Final Microbiology 2024-2025 PDF

Mansoura National University Faculty of Nursing MICROBIOLOGY FIRST LEVEL FIRST SEMSETER ACADEMIC YEAR 2024-2025 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Mansoura National Universit...

Mansoura National University Faculty of Nursing MICROBIOLOGY FIRST LEVEL FIRST SEMSETER ACADEMIC YEAR 2024-2025 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Mansoura National University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Prepared by: Prof. Dr. Rasha Barwa Prof. Dr. Dina Eid Professor of Microbiology and Immunology 2024/2025 1 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Introduction Microbiology plays a vital role in the foundation of nursing practice, offering essential insights into the microscopic world that profoundly affects human health. As a nursing student, your understanding of microorganisms— their structure, behavior, and impact—will equip you to prevent, diagnose, and manage infections with confidence and precision. This course is designed to provide nursing students with a comprehensive understanding of immunology, genetics, virology, mycology, and infection control—while emphasizing their relevance to clinical practice. 2024/2025 2 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 General Bacteriology 2024/2025 3 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Microbiology Microbiology: It is defined as the study of organisms that are too small to be seen clearly by the naked eye, that is the study of microorganisms. e.g. Bacteria, fungi, algae, and viruses Microorganisms are organized into fields of study: Bacteriology Virology Mycology Protozoology Parasitology. A microorganism: is simply a very, very small organism that you cannot see with your naked eye, but you sure feel its effect 2024/2025 4 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Bacteria are prokaryotic organisms A prokaryotic organism is a one-celled organism that does not have a true nucleus. Nomenclature: The first word =genus (first letter always capitalized) the second word= species (not capitalized). Both words are always italicized or underlined ex: Staphylococcus aureus or S. aureus or Staphylococcus aureus Bacillus anthracis or B. anthracis or Bacillus anthracis Escherichia coli or E. coli or Escherichia coli Typical structure of Bacterial cell: Cytoplasm ‫ ٭‬All components are present in all types of bacterial cells except capsule, pilus, and flagellum 2024/2025 5 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Capsule: - Composed of polysaccharides. - Protects bacterial cells from immune system or from attack by antibiotics. Flagellum: - For the movement of bacteria. Pilus: - Attachment of bacteria to surface of human cells. - Transfer of genetic material from one cell to another. Cell wall: - It is a rigid, porous layer. - Composed of polymeric material called murein (peptidoglycan). - Function: - It provides the definite shape of the bacteria. - Protects the cell from mechanical damage and lysis. The basic structure of peptidoglycan is an alternating series of two major subunits, N-acetylmuramic acid (NAM) N-acetylglucosamine (NAG). cross-linked to one another by tetrapeptide chains 2024/2025 6 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Cell membrane: - Composed of lipid bilayer that completely surrounds the cell and separates the inside from the outside. - Function: Control movement of substances (Ions, proteins, nutrients) between the cell and the surrounding environment. Cytoplasm: - It is the fluid that fills the cells and composed mainly of water and salts. - It contains different components of the cell (Components are called organelles). Ribosome: - Synthesis of proteins of the cell. - DNA or (Chromosome): - Carries all the genetic information of the bacterial cell. Plasmids are circular, supercoiled, double-stranded DNA molecules. - They carry EXTRA GENES that can be used for special situations such as antibiotic resistance, production of toxins synthesis of enzymes. 2024/2025 7 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Nucleoid region: - It is an irregularly shaped part of a bacterial cell where DNA is present. - It lacks the membrane that is found around the nucleus of eukaryotic cells. Other components (organelles) that are present in other living cells but not bacteria (eukaryotes): Mitochondria: - Synthesis and storage of energy (ATP) for the cell. Golgi apparatus: - Responsible for transporting, modifying, and packaging proteins and lipids for delivery to targeted destinations. Endoplasmic reticulum: - Folding of proteins (Allow proteins to take the functional structure and transport to Golgi apparatus. Nucleus: - Typical nucleus with a membrane. Scale of size of living organisms: 2024/2025 8 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Comparison between Prokaryotic and Eukaryotic cells: Eukaryotic cells Prokaryotic cells ‫حقيقيات النواة‬ Property ‫بدائية النواة‬ 1- Cell size Small cells (0.5 -5) µm Large cells (5 -50) µm 2- Nucleus Absent Present Cell division by binary 3- Cell division by mitosis and meiosis. fission. 4- Sexual systems absent present DNA composed of only DNA composed of: 5- DNA one chromosome 2-46 chromosomes 7- Mitochondria absent Present 8- Golgi apparatus absent Present 9- Endoplasmic reticulum absent Present 10- Examples: Bacteria Human cells, animal cells, fungi Additional resources Structure and Replication of Bacterial Cells Mechanisms of antibiotic action 2024/2025 9 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 1- In this bacterium “Bacillus anthracis” the genus is: a. Anthracis b. Bacillus c. Both a and b 2- Flagella in bacteria enable bacteria to a. Reproduce b. Move c. Nutrition d. No answer is true 3- The following components of the cell determine its shape: a. Cell wall b. Flagellum c. Capsule d. pili 2024/2025 10 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Bacterial shape and classification Shape of bacteria: Cocci: spherical in shape Bacilli: rod shape Cocco-bacilli: elongated bacilli Vibrio: comma-shaped Spirillum: spiral Arrangement of bacteria: Cocci: a) Diplococci: Pairs of cocci b) Streptococci: Chain of cocci c) Staphylococci: Grape-like structure d) Tetrads e) Sarcina Bacilli: a) Scattered: No special arrangement. b) Diplobacilli: pairs of bacilli c) Streptobacilli: Chains of bacilli 2024/2025 11 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Classifications of bacteria: According to the cell wall composition into: A- Gram positive Bacteria. B- Gram negative Bacteria. The ability of bacteria to cause disease (pathogenicity). A- Pathogenic bacteria: Able to cause a disease B- Non-pathogenic bacteria: Don’t cause a disease. According spore formation into: A- Endospore forming bacteria. B- Non-endospore forming bacteria. Bacterial classification according to the cell wall composition: Parameter Gram- Positive Gram-Negative Peptidoglycan layer Thick layer Thin layer Lipid content Low high Outer membrane Absent present (lipopolysaccharide) Teichoic acid, present Absent Lipoteichoic acid Gram stain Violet Red- purple Examples Staphylococcus aureus, Escherichia coli. Bacillus anthracis 2024/2025 12 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Outer membrane consists of lipid bilayer and lipopolysaccharides (LPS) LPS consists of: 1- Lipid A: It causes fever. 2- The polysaccharide moiety (O Antigen): Antigen: Means substance that stimulates the host immune system to produce antibodies. Types of bacteria that are not Gram-positive or negative bacteria: Cell wall free bacteria: e.g. Mycoplasma Acid fast bacteria: (Bacteria resistant to acids) - It has small amount of peptidoglycan and large amounts of glycolipids. - e.g. Mycobacterium tuberculosis 2024/2025 13 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Classifications of bacteria according to pathogenicity: Pathogenic bacteria Non-pathogenic bacteria Able to cause a disease. don’t cause a disease The degree of pathogenicity differs from one Normal flora or Commensal bacteria bacterium to another Present naturally in the human body (e.g. on skin, in mouth, in stomach, intestine) Present in the environment e.g.: Soil, Seawater, Rivers. Useful and used in the biotechnology field: - Streptomyces griseus from soil is used for production of Streptomycin. - Lactobacillus is used for production of yoghurt. Classifications of bacteria according to spore formation: Endospore: A specialized form of bacterial cells that allows bacteria to resist unfavorable conditions of growth. The structures may remain dormant for perhaps 100 years, or even longer, It is highly resistant to antimicrobial agents and sterilization process. 2024/2025 14 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 can germinate, to become a multiplying cell, called a vegetative cell. Bacteria are classified according to spore formation into: Endospore forming bacteria usually Non-endospore forming bacteria bacillus bacteria e.g. Bacillus anthrax. Microbial growth requirements I. Nutritional requirements. II) Environmental requirements. 1- Macronutrients 1- Temperature 2- Trace elements 2- pH. 3- Growth factors 3- Oxygen. 4- Osmotic pressure (Salt concentration). 2024/2025 15 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 I.Nutritional requirements. 1- Macronutrients: Microorganisms require about ten elements in large quantities, because they are used to construct carbohydrates, lipids, proteins, and nucleic acids. They constitute 95% or more of cell dry weight: Carbon, oxygen, nitrogen, sulfur, phosphorus, hydrogen, potassium, calcium, magnesium and iron. 2- Trace elements: Needed in very small amounts and act as parts of enzymes and cofactors. Usually mineral elements: such as copper, molybdenum, and zinc. 3- Growth factors: A- Amino acids: are needed for protein synthesis. B- Purines and pyrimidines are needed for nucleic acid synthesis. C- Vitamins: make up all or part of enzyme cofactors 2024/2025 16 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 1- Examples of the useful use of microorganisms in biotechnology is Production of: A. Bread B. Insulin C. Both A & B D. No answer is correct 2- S. aureus differs from E. coli in that: A. It contains no cell wall B. It contains no cell membrane C. It contains no periplasmic space D. All the above 3- The organelle that is responsible for protein synthesis is: A. Ribosome B. Mitochondria C. Endoplasmic reticulum D. Golgi apparatus 4- The following shape of bacteria is called: A. Cocci B. Vibrio C. Bacilli D. Spiral 5- Bacteria A is less pathogenic than B, this means that bacteria A: a. More able to cause a disease b. Difficult to be detected in labs. c. Both a and b. d. No answer is correct 2024/2025 17 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Microbial growth Microbial growth requirements II. Environmental requirements. 1- Temperature: According to the optimum temperature for growth the organism can be classified into: a) Psychrophiles: - Grow best between 0-15 oC. - None can live in the human body. - Cause spoilage of refrigerated foods. b) Mesophiles: - Include most microorganisms and grow best between 25 and 40 oC. - Human pathogens are included in this category and most grow best near human body temperature (37 oC). c) Moderate thermophiles: - Grow best between 55 and 65 oC. (Bacteria live in hot springs) d) Extreme thermophiles: - Grow best between 80 and 113 oC. (Bacteria live in volcanic vents) - 2024/2025 18 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 2- PH: - Most bacteria prefer neutral pH (6.5-7.5). - Fungi and yeast grow in acidic pH between 5 and 6. - Acidity inhibits most microbial growth and is used frequently for food preservation (Ex. pickling). - Alkalinity inhibits microbial growth but is not commonly used for food preservation. 3- Oxygen requirement: a) Aerobic: Growth occurs only in the presence of oxygen. b) Obligate anaerobes: Growth occurs only in the absence of oxygen. c) Facultative anaerobes: Growth is best in the presence of oxygen but can grow in its absence. d) Aerotolerant anaerobes: Anaerobic bacteria that can grow in the presence of oxygen. e) Microaerophilic: Aerobic organisms that do not tolerate atmospheric concentrations of oxygen. Growth occurs only at a lower level of oxygen concentration. 2024/2025 19 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Microbial growth & reproduction: Microbial growth: an increase in the number of cells. Reproduction of bacteria occurs by binary fission. Growth curve: Microbial growth is measured by the growth curve. Growth cycle of microbes composed of four characteristic phases: 2024/2025 20 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 (a) Lag phase: cells begin to synthesize inducible enzymes and use stored food reserves to start reproduction (0-2 h from cultivation) (b) Logarithmic (log = exponential) phase: The number of cells increases exponentially. (2-8 h from cultivation) (c) Stationary phase: The number of cells is constant. (8-20 h from cultivation) - reproduction rate is equal to death rate (d) Death (decline) phase: The number of cells decrease. (After 20 h cultivation) - death rate is more than reproduction rate Cultivation of bacteria Culture media: Nutrient material prepared for the growth of microorganisms Can be used to: - Enrich the numbers of bacteria - Select for certain bacteria and suppress others. - Differentiate among different kinds of bacteria The media may be: Liquid medium Components are dissolved in water and sterilized. Solid medium A medium to which has been added a gelling agent [Agar (most commonly used), Gelatin, Silica gel] 2024/2025 21 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Types of culture media There are two basic types of media: A- Complex media B- Synthetic media A- Complex media - Often consist of plant or animal extracts, such as soybean meal, milk protein, etc. Include most routine laboratory media. e.g., tryptic soya broth 1- Basal media: E.g. nutrient broth/agar 2- Enriched media - Complex medium to which additional nutrients are added (blood or serum) - Eg. Blood agar medium 3- Selective media - media contain a selective agent, allowing some bacteria to grow, while inhibiting other bacteria. Eg. Lowenstien-Jensen (L-J) media 4- Differential media - Medium contains substances that allow certain groups of bacteria to appear differently when growing on it (differential agent). - Eg. blood agar 5- Selective and Differential - Media has both selective and differential agent - Eg. Mannitol Salt Agar 2024/2025 22 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 B- Synthetic media - Chemically defined media. - Contain pure chemical compounds. - Ingredient must be of analytical quality. - Water must be distilled. Identification of microorganism 1. Microscopy 3. Biochemical - Staining: Gram, Zeel-Nielsen - Oxygen requirement - Shape and arrangement - Enzymes 2. Culture 4. Serology: antigen antibody interaction - Media: liquid, solid, differentiate, 5. Genetic selective - Morphology Bacterial Growth in the Lab Additional resources Identify the oxygen requirement of organisms in tubes 1-6 2024/2025 23 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 1- Which of the following describes bacteria that grow best near the surface, where oxygen is available, but growth occurs throughout the tube? A. Obligate aerobes B. Obligate anaerobes C. Facultative anaerobes D. Aerotolerant anaerobe 2- What is the name of bacteria that live at high temperature (80-113 ºC)? A. Psychrophiles B. Mesophiles C. Hyperthermophiles D. Alkaliphiles 3- During which stage of bacterial growth curve, the reproduction rate is equal to death rate? A. Decline phase B. Stationary phase C. Lag phase D. Log phase 4- Bacteria reproduce by: A. Binary fission B. meiosis C. mitosis D. No answer is correct 2024/2025 24 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Genetics 2024/2025 25 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Genetics The branch of science that studies heredity and how traits are passed to new generations of species and between microorganisms Our genes are on our chromosomes. Chromosomes are made up of a chemical called DNA. Function - DNA carries the instructions for the development, growth, reproduction, and functioning of all life. Structure of DNA DNA consists of two long chains (two strands) that twist around each other, forming a double helix Each strand consists of repeating nucleotides The backbone of DNA strand consists of: phosphate alternating phosphate and deoxyribose sugar. deoxyribose A nucleotide in a DNA chain consists of bases 1. A nitrogenous base 2. A phosphate group 3. Sugar (deoxyribose) 2024/2025 26 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 There are two major types of nitrogenous bases. Adenine (A) Purines Guanine(G) Cytosine (C) Pyrimidines Thymine (T). The two DNA chains are held together by hydrogen bonds between their nitrogenous bases. The deoxyribose sugars are joined at both the 3'-hydroxyl and 5'-hydroxyl groups to phosphate groups in ester links, which are known as "phosphodiester" bonds. DNA Composed of parallel strand and anti- parallel strand (one oriented 5’– 3’ and the other 3’ – 5’) The two chains of the double helix have complementary sequence sequence 5’-A T G T C-3’ complementary sequence 3’-T A C A G-5’ 2024/2025 27 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 In prokaryote the DNA is supercoiled In eukaryote, the super coiled DNA binds with proteins to form chromatin that make up the contents of the nucleus of a cell. Chromosome: It is a single DNA molecule In bacteria there is a single chromosome while in Human there are 46 chromosomes (23 x 2) Genes: Are part of DNA that carry the information for a phenotypic character ⮚ Eukaryotic genes; are characterized by the presence of ▪ Introns (noncoding sequences) ▪ Exons (coding sequences) 2024/2025 28 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 RNA (Ribonucleic acid) structure: RNA is a single-stranded polynucleotide that contains ribose as a sugar moiety uracil instead of thymine. 2024/2025 29 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Types of RNA according to function messenger RNA (mRNA): carries genetic codes from the DNA in the nucleus to ribosomes transfer RNA (tRNA): bring the specified amino acids to the ribosomes, where they are linked to form proteins ribosomal RNA (rRNA): encodes ribosome protein subunits Transcription: DNA ---> mRNA in Prokaryotes ⮚ DNA serves as a template for RNA synthesis ⮚ A codon is a sequence of three nucleotides ⮚ Codons, translated into chains of amino acids (polypeptides, proteins) Translation: mRNA---> Protein 3` to 5` is the template strand tRNA and rRNA 2024/2025 30 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Codons for amino acids Transcription Additional resources Protein translation 2024/2025 31 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Immunology 2024/2025 32 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 The Immune System Immunology: It is the science that deals with the parts of immune system and how the immune system overcomes foreign organisms. Importance of immune system Defense against infections e.g pathogenic bacteria, fungi and viruses. Defense against tumors (Cancer). Clearance of dead tissues and repair. Antigen It is any foreign material causing an immune response, Typically, they are proteins, polypeptides, or sugars Examples of Antigens Bacterial cell wall components, such as lipopolysaccharides. Proteins on the surface of viruses. Pollen grains. Transplanted tissue or organ cells from another individual. Markers on blood cells and tumor cells 2024/2025 33 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Antibody Antibodies are proteins formed in the body by immune system in response to antigen. It reacts specifically with antigen that stimulate their production They are called immunoglobulins (Igs). Organs and cells of the Immune System Organs of immune system Primary Lymphoid Secondary lymphoid Tonsils (‫)اللوز‬ organs organs and adenoids Thymus I. Thymus I. Lymph nodes Bone II. Bone marrow II. Spleen Lymph III. Skin nodes IV. Tonsils Spleen V. Small intestine Peyer’s Lymph Appendix nodes 2024/2025 34 ‫دودية زائدة‬ National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Cells of immune system Blood consists of three Types of cells: White blood cells Red blood cells Platelets plasma White blood cells (Leukocytes) are the cells of the immune system. Granulocytes: Neutrophils: are often the first cells to leave the blood and fight incoming pathogens can perform phagocytosis are the most abundant type of granulocytes 2024/2025 35 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Eosinophils: play a role in defense against parasitic infections. Basophils: Play a role in both parasitic infections allergies Antigen-presenting cells are immune cells that capture foreign pathogens, process their antigens, and present them on their surface Ex: dendritic cells Macrophages B cells Lymphocytes: B- cells: produces antibodies T cells: mediate cellular immunity Natural killer cells: innate immune system that control several types of tumors and microbial infections 2024/2025 36 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 - The immune system is composed of two major subdivisions: I-The innate system II-The adaptive, acquired nonspecific immune system specific immune system The first and second line of The third line of defense defense ❑ I- The innate system. first lines of defense Non-specific defenses are designed to prevent infections by viruses and bacteria. There is immediate maximal response These include the skin mucous membranes saliva Tears stomach acidity bacterial normal flora on skin, in mouth and stomach Second line of defenses Fever Inflammation Antimicrobial proteins e.g. Interferon. Phagocytosis (phagocytes) NK (natural killer) 2024/2025 37 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 ❑ II-The adaptive, acquired Third lines of defense specific defenses There is a lag time between exposure and maximal response (days) The adaptive immune response is divided into two systems: Humoral immunity Cellular immunity Humoral immunity Cellular immunity Mediated by B cells. T cells are the main cells of cellular They mature in bone marrow. immunity. They are produced in bone marrow They mature in Thymus. o Once activated by antigen, divide in They are differentiated into blood and secondary lymphatic Cytotoxic T cells (killer T cells) Helper T cells organ into two types of cells: Suppressor T cells Plasma cells that secrete antibodies Memory T cells. Memory cells. 2024/2025 38 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 2024/2025 39 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Comparison between innate and acquired immune system Innate Immune system Acquired Immune system Response Fast Response Slow response (minutes to few hours) (10 days) Specificity Non-specific specific Cells do not distinguish invaders Memory no immunologic memory Immunologic memory Additional resources Innate immunity Adaptive immunity 2024/2025 40 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 One of the first line defense mechanisms a) Fever b) Inflammation c) phagocytosis d) Respiratory cilia Which the following are considered as adaptive immune response? a) Inflammation. b) Fever c) Phagocytosis. d) Production of antibodies The innate immunity is characterized by: a) Have memory cells b) Protect against specific pathogens c) Provide antibody for protection d) Exist from birth All the following are secondary organs of immune system EXCEPT a) Lymph nodes b) Bone marrow c) Tonsils d) Spleen The second line defense includes: a) Inflammation b) Fever c) Phagocytosis d) All answers are correct 2024/2025 41 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Antibodies Antibodies (Ab) or immunoglobulins (Ig) are large Y-shaped protein molecules produced by plasma cells that bind to antigens that occur on pathogens. Each antibody consists of Two identical heavy chains Two identical light chains. Disulfide bonds connect the chains. The region at the top of the “Y” has variable amino acids that form the antigen binding site. 2024/2025 42 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Humans have 5 Types of antibodies: 1. Immunoglobulin A (IgA): 2. Immunoglobulin D (IgD) 3. Immunoglobulin E (IgE) 4. Immunoglobulin G (IgG) 5. Immunoglobulin M (IgM). 1. Immunoglobulin A (IgA): ✓ occurs in breast milk, tears, and saliva ✓ the antibody that helps protect breast-fed babies from infection. 2. Immunoglobulin D (IgD) ✓ B cells produce it as a signaling antibody that stimulates the release of IgM antibodies. 3. Immunoglobulin E (IgE): ✓ responsible for allergic reactions ✓ protects the body from parasitic infections 2024/2025 43 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 4. Immunoglobulin G (IgG) ✓ the most abundant antibody (80%) ✓ the only antibody class that crosses the placenta ✓ For diagnosis of chronic infection. 5. Immunoglobulin M (IgM): ✓ Produced in early or acute infection. ✓ the first antibodies formed for fighting an infection Immunization ❖ Immunization: is the process whereby a person naturally acquires or is induced to acquire immunity or resistance to an infectious disease. ❖ An individual can acquire such immunity either passively or actively Passive immunity: o passive immunization, a person receives antibodies that have been produced by another individual’s immune system Active immunity: o The individual’s own immune system is stimulated to produce antibodies. 2024/2025 44 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 1- Passive immunity o passive immunization, a person receives antibodies that have been produced by another individual’s immune system A- Natural From mother to fetus across the placenta From mother to baby through breast milk. B- Artificial injection of antibodies, that are e developed in another individual or animal 2024/2025 45 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 2- Active immunity The individual’s own immune system is stimulated to produce antibodies. A- Natural when an individual is exposed to an antigen or pathogen B- Artificial by means of vaccines There are several types of vaccines, including: 1. Live-attenuated vaccines: a weakened (or attenuated) form of the germ that causes a disease 2. Inactivated vaccines: killed version of the germ that causes a disease 3. Messenger RNA (mRNA) vaccines: make proteins in order to trigger an immune response. 4. Protein Subunit vaccines: fragments of proteins or polysaccharides of a pathogen 5. Virus -like protein (recombinant): molecules that mimic viruses but are not infectious 6. Viral vector 2024/2025 46 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 2024/2025 47 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Immune System Disorders Immune system disorders cause abnormally low activity, over activity or misguided activity of immune system. Hypersensitivity: Too much - Excessive immunologic responses occurring in response to an antigen or allergen Autoimmunity: Misdirected - The body's natural defense system can't differentiate between self-antigen and foreign antigens, causing the body to mistakenly attack normal cells. Immunodeficiency: Too little - A failure or absence of elements of the immune system 2024/2025 48 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 1- The antibody formed in the first 4- The antibody that has a role in infection is: allergy is: a) Immunoglobulin A (IgA) a) Immunoglobulin A (IgA) b) Immunoglobulin D (IgD) b) Immunoglobulin D (IgD) c) Immunoglobulin E (IgE) c) Immunoglobulin E (IgE) d) Immunoglobulin G (IgG) d) Immunoglobulin G (IgG) e) Immunoglobulin M (IgM) e) Immunoglobulin M (IgM) 2- The most abundant antibody is: 4- The antibody that can cross the a) Immunoglobulin A (IgA) placenta is: b) Immunoglobulin D (IgD) a) Immunoglobulin A (IgA) c) Immunoglobulin E (IgE) b) Immunoglobulin D (IgD) d) Immunoglobulin G (IgG) c) Immunoglobulin E (IgE) e) Immunoglobulin M (IgM) d) Immunoglobulin G (IgG) e) Immunoglobulin M (IgM) 3- The antibody found in tears and breast milk is: 4- The antibody that has a role in a) Immunoglobulin A (IgA) parasitic infection in: b) Immunoglobulin D (IgD) a) Immunoglobulin A (IgA) c) Immunoglobulin E (IgE) b) Immunoglobulin D (IgD) d) Immunoglobulin G (IgG) c) Immunoglobulin E (IgE) e) Immunoglobulin M (IgM) d) Immunoglobulin G (IgG) e) Immunoglobulin M (IgM) 5- A failure or absence of elements of the immune system is known as ……… 6- Excessive immunologic responses on exposure to an allergen is …….. 2024/2025 49 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Systematic Bacteriology 2024/2025 50 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Host-microbe interaction ‫ ٭‬Medical Microbiology: is a science of studying micro-organisms that are associated with human disease ‫ ٭‬This field focuses on pathogens, diseases, and body defenses Some Important definitions: Colonization Establishment and growth of a microorganism on a body surface. Infection: Infection is the entry and development or multiplication of an infectious agent in the body of man or animals. Disease: Change from a state of health Health: A state of complete physical, mental and social well being Etiology of the disease: Study of the cause of a disease Principles of Infectious Disease An infection that results in disease is called an infectious disease. Diseases are characterized by symptoms and signs Effects of one disease may leave a person predisposed to developing another. Primary infection: The initial infection Secondary infection: an additional infection that occurs as a result of the primary infection. Pathogenicity Microorganisms are classified according to pathogenicity (the ability to cause a disease) into: 1- Non-pathogen: A microorganism that does not cause disease. It may be part of the normal flora. 2- Pathogen: A microorganism capable of causing disease in healthy individuals. 2024/2025 51 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 3- Opportunistic pathogen: microbe able to cause disease only when the body’s innate or adaptive defenses are compromised (immunocompromised), or when introduced into an unusual location Virulence: the degree or intensity of pathogenicity Virulence Factors (Determinants): Attributes of a microorganism or virus that promote pathogenicity Characteristics of Infectious Disease Course of Infectious Disease The course of an infectious disease includes several stages 1- Incubation period - The time between acquisition of the organism & the beginning of symptoms - It varies from only a few days (common cold), to several weeks (hepatitis A), to many months (rabies), and even years (leprosy). 2- Illness: - A phase that follows the incubation period. - a person will experience the signs and symptoms of the disease. Symptoms = subjective changes in bod function. e.g. pain o Evidence of a disease that is experienced by the patient o Cannot be measured Sign = objective changes in body function that can be measured e.g. fever o Evidence of a disease that is observed by others (doctors, nurses, … ) o Can be measured Syndrome = specific group of symptoms & signs that may accompany a particular disease 2024/2025 52 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Convalescence: the stage of recovery from the disease. Duration of Symptoms Acute infections are characterized by symptoms that have a rapid onset but last only a short time; an example is strep throat. Chronic infections develop slowly and last for months or years; an example is tuberculosis. Latent infections: the microbe continues to exist in host tissues, often within host cells, for years without causing any symptoms. If there is a decrease in immune response, the latent infection may become reactivated and symptomatic. Distribution of the Pathogen Infections are often described according to the distribution of the causative agent in the body.: localized infection: the microbe is limited to a small area; an example is a boil systemic (generalized) infection: the infectious agent is spread, or disseminated, throughout the body; an example is measles. Note: bacteremia: bacteria are circulating in the bloodstream. Toxemia: toxins circulating in the bloodstream Viremia: viral particles circulating in the bloodstream. Septicemia: an acute, life-threatening illness caused by infectious agents or their products circulating in the bloodstream. 2024/2025 53 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Establishing the Cause of Infectious Disease Germ theory (Koch’s Postulates) Robert Koch proposed that in order to conclude that a microbe causes a particular disease, these postulates must be fulfilled: 1. The same pathogen must be present in every case of the disease. 2. The pathogen must be isolated from the diseased host and grown in pure culture. 3. The pathogen from the pure culture must cause the same disease when it is inoculated into a new healthy susceptible animal host 4. The pathogen must be isolated from the inoculated Sick animal and must be shown to be the same original pathogen. 2024/2025 54 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Why do people get infectious diseases? People get infectious diseases when microorganisms overpower our host defenses (i.e., when the balance between the organism and the host shifts in favor of the organism). From the organism’s perspective - The number of organisms to which the host, or person, is exposed - The virulence of these organisms - Incubation Period From the host’s perspective, Immunity, age, gender, General health: malnutrition, Chain of Infection Components The chain of components has six sections. They include: Infectious agent is the pathogen (germ) that causes diseases Reservoir includes places in the environment where the pathogen lives (this includes people, animals and insects, medical equipment, and soil and water) Portal of exit is the way the infectious agent leaves the reservoir (through open wounds, aerosols, and splatter of body fluids including coughing, sneezing, and saliva) Mode of transmission is the way the infectious agent can be passed on. Portal of entry is the way the infectious agent can enter a new host (through broken skin, the respiratory tract, mucous membranes, and catheters and tubes) Susceptible host Young children, elderly, patients with chronic disease, malnutrition, immunocompromised 2024/2025 55 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Routes of Transmission: The mode of transmission of many infectious diseases can be from human-to-human or nonhuman sources by: 1- Contact Direct contact transmission (touching, Sexual Contact) Indirect contact: Fomite (nonliving surfaces contaminated with an infectious agent) like doorknobs, telephones, towels, cups, and utensils. 2- Airborne Aerosol Infectious agents (bacteria, viruses, etc) are carried in the air via aerosols (long-lasting particles) 3- Respiratory droplet an infected person coughs or sneezes on or near you the respiratory droplets can either enter directly into the nose or mouth or land on unwashed hands and spread 2024/2025 56 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 4- Enteric (fecal-oral) spread via from the feces of an infected individual to the mouth another individual - poor hygiene - food and water. 5- Vector-borne: Vectors: The term “vector” applies to any living organism that can carry a disease-causing microbe such as mosquitoes, fleas, lice, and ticks. 6- Blood transfusion: introduction of a pathogen via blood transfusion 7- Vertical (maternal-fetal) pathogen that is passed from mother to child either in utero (via the placenta), or during childbirth Chain of infection 2024/2025 57 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 1- Which of the following is considered as portal of exit? A- Tears B- Saliva C- urine D- All the above 2- Which of the following represents the route of infection transmission by fomites? A- Direct contact B- Respiratory droplet C- Feco-oral D- vertical 3- Evidence of a disease that is observed by others is: A- Symptom B- infection C- sign D- no answer is true 4- Which of the following represents convalescent period? A- time between acquisition of the organism & the beginning of symptoms B- phase of the signs and symptoms of the disease. C- stage of recovery from the disease D- no answer is true 2024/2025 58 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Common Bacterial Diseases Importance: Recognizing and managing bacterial infections is key to patient care, particularly in infection control and prevention. Gastrointestinal Infections Salmonellosis Causative Agent: Salmonella species Transmission: Consumption of contaminated food (especially undercooked poultry, eggs, and dairy) Common Symptoms: Diarrhea (sometimes bloody), fever, abdominal cramps, nausea, vomiting Prevention: Food safety practices, hand hygiene. Nursing Focus: - Dehydration management - infection control. Shigellosis Causative Agent: Shigella species. Transmission: Fecal-oral route, contaminated food/water. Symptoms: Bloody diarrhea, abdominal pain, fever. Prevention: Hand hygiene, safe food handling. Nursing Focus: Monitor for dehydration, isolation to prevent spread. 2024/2025 59 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Cholera Causative Agent: Vibrio cholerae Transmission: - contaminated water or food Common Symptoms: Profuse watery diarrhea ("rice-water stools"), dehydration, vomiting, muscle cramps, shock in severe cases prevention: Safe water and sanitation. Nursing Focus: Immediate rehydration (oral or IV fluids). Botulism Causative Agent: Clostridium botulinum Common Symptoms: Nausea, vomiting, diarrhea (initial), followed by neurological symptoms like blurred vision, muscle weakness, paralysis Transmission: - Ingestion of contaminated food (especially improperly canned or preserved foods) Helicobacter pylori Infection Causative Agent: Helicobacter pylori Common Symptoms: Indigestion or burning stomach pain, nausea, bloating, peptic ulcers, potential stomach cancer Transmission: Person-to-person contact via saliva or fecal-oral route Contaminated food or water 2024/2025 60 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Prevention: Good hygiene: Handwashing, safe food and water practices. Avoid sharing utensils in areas where transmission is common. Respiratory tract infection Pneumonia Causative Bacteria: Streptococcus pneumoniae (most common cause of bacterial pneumonia) Staphylococcus aureus, Mycoplasma pneumoniae Haemophilus influenzae, Mode of Transmission: - Spread via respiratory droplets from coughs and sneezes. - Can be acquired in hospital settings (hospital-acquired pneumonia) or the community (community-acquired pneumonia). Common Symptoms: Cough, fever, chills, difficulty breathing chest pain Fatigue and weakness. 2024/2025 61 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Prevention: - Vaccination: Pneumococcal vaccines. - Hand hygiene: Regular handwashing to prevent spread. - Respiratory hygiene: Covering mouth when coughing or sneezing. Strep Throat Causative Bacteria: Streptococcus pyogenes Mode of Transmission: - Spread via respiratory droplets from coughs and sneezes. - Can also spread by sharing utensils or surfaces with an infected person. Common Symptoms: Sore throat difficulty swallowing, red and swollen tonsils (sometimes with white patches) fever. Swollen lymph nodes in the neck. Complication: Rheumatic fever Prevention: - Good hygiene practices: Handwashing, avoiding sharing utensils with infected individuals. - Covering coughs and sneezes to reduce spread. - Prompt treatment: Early antibiotic treatment to prevent complications like rheumatic fever. 2024/2025 62 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Tuberculosis (TB) Causative Bacteria: Mycobacterium tuberculosis Mode of Transmission: - Spread via respiratory droplets from coughs and sneezes. Common Symptoms: Persistent cough (lasting more than 3 weeks), fever, night sweats, and weight loss. Coughing up blood in advanced stages. Prevention: BCG vaccine. Nursing Focus: Patient isolation, respiratory precautions, medication adherence. Urinary Tract Infections (UTIs) Causative Bacteria: Escherichia coli (most common, causing about 80% of cases) Other bacteria: Proteus, Klebsiella, Staphylococcus saprophyticus. Mode of Transmission: - Often results from bacteria from the gut entering the urinary tract, typically through the urethra. - Risk factors include sexual activity, poor hygiene, catheter use, and certain medical conditions. 2024/2025 63 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Common Symptoms: cloudy or bloody urine. Strong odor Burning sensation when urinating, frequent urge to urinate Lower abdominal pain, sometimes accompanied by fever in severe cases. Prevention: Good personal hygiene: Regular washing of the genital area. Stay hydrated: Drinking plenty of water to flush out bacteria. Proper catheter care: In hospital settings, use of sterile techniques and early removal of catheters. Bacterial Meningitis Bacterial meningitis is a bacterial infection of the meninges, which is the protective covering for the brain and spinal cord resulting in inflammation. Causative Bacteria: Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae. Mode of Transmission: - Spread via close contact, coughing, or sharing utensils. - In some cases, it may follow an ear or sinus infection. 2024/2025 64 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Common Symptoms: - Severe headache - stiff neck - fever and vomiting. - sensitivity to light, nausea, and vomiting. - In severe cases, mental confusion and seizures. Prevention: Vaccination Early treatment. Public health measures: Avoid close contact with infected individuals. Staphylococcus aureus infections: https://www.cdc.gov/staphylococcus-aureus/about/index.html https://www.webmd.com/skin-problems-and- treatments/staph-infection-cellulitis 2024/2025 65 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 General Nursing Focus in Bacterial Infections: Infection Control: (hand hygiene, isolation). Vital Signs Monitoring: Regularly assess for signs of sepsis or worsening infection. Antibiotic Management: Ensure timely and complete administration Hydration: Maintain fluid balance, especially in febrile or GI infections. Symptom Management: Administer pain relief and manage fever. Patient Education: Teach about infection prevention, treatment adherence, and warning signs. Nutritional Support: Promote adequate nutrition and modify diet if needed. Complication Monitoring: Watch for sepsis, organ failure, or other complications. Wound Care: Properly clean and monitor wounds for signs of infection. 2024/2025 66 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Virology 2024/2025 67 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Viruses General Properties They are the smallest infectious agents. ` They infect man, animals, plants and bacteria. In contrast to bacteria, fungi and parasites, viruses are not cells. They contain one kind of nucleic acid (RNA or DNA). They are obligate intracellular parasites; hence they cannot grow in artificial medium. They do not have nucleus, cytoplasm, mitochondria, or ribosomes. They cannot generate energy or synthesize protein. Virus Size a- Very small organisms 25- 250 nm Comparative Sizes of Viruses and Bacteria 2024/2025 68 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Structure of viruses The simplest viruses are constructed of a nucleocapsid which is composed of nucleic acid held within a protein coat called capsid. Nucleic acid core. Protein coat (capsid). Envelope. 1- Viral nucleic acid: - Only one type of nucleic acid (DNA or RNA). - Depending on the type of nucleic acid they contain, viruses are frequently referred to as RNA or DNA viruses 2- Viral Capsid - The capsid, composed of a defined number of protein units called capsomers, is held together by non-covalent bonds. - Functions: 1- Protect viral genome. 2- Give the virus its geometrical symmetry: 2024/2025 69 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Virus shape A- Icosahedral: 20 identical equilateral triangles, (eg. Herpes) B- Helical: tubular C- Complex: icosahedral heads bound to helical tails. eg: Bacteriophage 3- Viral envelope: According to presence or absence of envelope Naked virus: Enveloped viruses: no additional Covering outside an envelope surrounds the protein capsid coat Spikes (Peplomer) project from the capsid or the envelope and are involved in attaching the virus to the host cell (attachment proteins) 2024/2025 70 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Viral replication 1. Attachment 2. Entry 3. Uncoating 4. Replication 5. Assembly 6. Release 1. Attachment Attachment of the virus to the host cell by interaction between specific proteins on viral surface and specific receptors on target cell membrane The attachment sites of one group of viruses differ from the others. (Host specificity) 2. Entry Three modes of entry of viruses occur: (a) Direct penetration: 2024/2025 71 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 (b) Fusion with plasma membrane: (c) Endocytosis: 3. Uncoating: The viral capsid is removed and degraded by viral enzymes or host enzymes releasing the viral genomic nucleic acid. 4. Replication: synthesis of viral proteins and genome. Important enzymes for replication: a. DNA polymerase in DNA viruses b. RNA polymerase in RNA viruses c. Reverse transcriptase converts RNA to DNA in HIV. d. Protease catalyzes the proteolytic cleavage of viral precursor proteins 2024/2025 72 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 5. Assembly Viral proteins are packaged with newly replicated viral genome into new virions that are ready for release from the host cell. 6. Release - Lysis: rupture of cell membrane - Exocytosis - Budding through outer cell membrane. 2024/2025 73 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Additional resources According to the video: 1- Enveloped viruses enter the cell by………….. 2- Naked viruses enter the cell by……. 3- A common mechanism of entry of enveloped and naked viruses is……… 2024/2025 74 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 1- The following is true regarding viruses: A. It can replicate in milk B. The genetic information is stored always on DNA C. It is unable to generate energy or synthesize protein D. All the above 2- Viruses can exit the infected cells by A. Budding B. Endocytosis C. Lysis D. Both A and C 3- A common entry method of both naked and enveloped viruses A. Exocytosis B. Direct penetration C. Membrane fusion D. Endocytosis 2024/2025 75 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Viral diseases DNA viruses RNA viruses Herpes Simplex -1 Enveloped Influenza Enveloped Rhinovirus Varicella-Zoster Enveloped Hepatitis C HCV Enveloped Rabies virus Enveloped Hepatitis B Enveloped HIV (AIDs) Enveloped Rota virus Non enveloped, naked COVID-19 Enveloped 2024/2025 76 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Herpes simplex virus 1 Transmission: direct contact with virus-containing secretions Disease Primary infections: Gingivostomatitis in young children tonsillitis and pharyngitis in adults Latency: trigeminal ganglia Reactivation: ("cold sores" or "fever blisters") around the lips 2024/2025 77 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Varicella-Zoster Transmission: respiratory droplets Disease Primary infections: Varicella (chickenpox) fever, malaise, headache, abdominal pain virus-containing vesicles ("pox") causing severe itching Latency: trigeminal and dorsal root ganglia Reactivation: Zoster (shingles): a painful, usually itchy, rash that develops on one side of the face or body. Most commonly on the trunk But can occurs around one eye or one side of neck or face Prevention: Vaccine varicella vaccine for children and adolescent shingles vaccine is recommended for some older adults and people with a severely weakened immune system. 2024/2025 78 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Hepatitis B virus Transmission: Infectious HBV is present in all body fluids so can be transmit through: Disease 1. Acute hepatitis: In about two thirds of individuals is asymptomatic In acute HBV infections: - Incubation period (45 and 120 days) - Preicteric (prejaundice) period (few days- week) - The acute, icteric phase (1-2 months) - Convalescent period of several more months is followed by complete recovery (80-90% of adults 2. Fulminant hepatitis More extensive necrosis of the liver occurs 3. chronic disease Following resolution of the acute disease (or asymptomatic infection), About 2 -10 % of adults and over 25 % of young children remain chronically infected. Prevention: HBV vaccination is as a routine infant immunization 2024/2025 79 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Rhinovirus Influenza virus Transmission: respiratory droplets made when people cough, sneeze, or talk Disease: common-cold Flu Symptoms: Prevention: - Vaccination (Influenza) - Clean your hands. - Avoid touching your eyes, nose or mouth - Cover your mouth and nose. - Stay home when you are sick. - Avoid close contact. 2024/2025 80 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Hepatitis C virus Transmission: a bloodborne virus Disease Symptoms Fever feeling very tired loss of appetite nausea and vomiting abdominal page dark urine pale feces joint pain jaundice (yellowing of the skin or eyes). Prevention: There is no vaccine to prevent hepatitis C. The best way to prevent hepatitis C is by avoiding behaviors that can spread the disease 2024/2025 81 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Rabies virus Transmission: infected saliva through bite of an animal (dog, cats,…) Disease: Rabies Once clinical symptoms appear, rabies is virtually 100% fatal. Symptoms incubation period: 2-3 months Initial symptoms: fever, pain and unusual or unexplained tingling, or burning sensations at the wound site. There are two forms of rabies: Furious rabies: hyperactivity, hallucinations, hydrophobia (fear of water) Death occurs after a few days Paralytic rabies: longer course than the furious form Muscles gradually become paralyzed, coma, death Prevention: Pre-exposure prophylaxis (PrEP) recommended for individuals at higher risk 2024/2025 82 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 because of their occupation, travel or residence in an endemic setting post-exposure prophylaxis 1- washing the wound with water and soap for approximately 15 minutes, 2- Immediate vaccination. Hydrophobia 2024/2025 83 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Influenza virus replication Corona virus 1. An example of RNA virus is: 3. Rabies is transmitted by: A. COVID-19 A. Bite of dog B. HBV B. Respiratory droplet C. HIV C. Skin contact D. Both A & C D. Ingestion 2. An example of DNA virus is: 4. Reactivation of Herpes simplex 1 A. COVID-19 results in: B. HCV A. Shingles C. Herpes B. Chicken pox D. No answer is correct C. Cold sores D. Hydrophobia 2024/2025 84 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Summarize the lecture Virus Mode of Disease Important prevention transmission symptoms 2024/2025 85 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Mycology 2024/2025 86 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Fungi ❖ Mycology: It is the scientific study of fungi. Structure of fungi 1-Fungal cell wall composition Consist of polysaccharides, chitin, mannan, glucan. 2- The plasma membrane Structure: sterol ergosterol 3- Fungal nuclei Surrounded by Nuclear membrane Contain chromosomes 4-Other organelles Mitochondria Golgi bodies Other types: - Ribosomes 80 S(40S, 60S) - Endoplasmic reticulum, vacuoles, lipid bodies, vesicles Classification: Yeasts Molds Mushroom Unicellular Multicellular 2024/2025 87 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Shape It could be: ⮚ Unicellular, basic form is the yeast cell. ⮚ Multicellular, basic form is the filamentous hypha - intertwined hyphae are called mycelium. ⮚ Sometimes fungi can exist in two morphological forms (dimorphic) Yeast cell Hypha Mycelium Reproduction o Budding: o Spore formation: 2024/2025 88 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Spores of fungi germinate to form a projection from the side of the cell called a germ tube Germ cells elongate to form hyphae. Hyphae continue to grow to form a mycelium. Hypha: a long, branching, filamentous structure of a fungus that is the main mode of vegetative growth Mycelium: a mass of hyphae Dimorphic fungi: can grow either as yeast-like cells or as mycelia, depending on the environmental conditions. Cultivation and growth conditions ▪ Optimal pH 4-6 ▪ Optimal temperature 22-28 C ▪ pathogenic fungi 37 C. ▪ Media; Sabouraud’s dextrose agar. 2024/2025 89 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Fungal benefits: ❑ Food industry - Yeast or Saccharomyces cerevisiae: wine, beer, cheese, bread. ❑ In Biotechnology in the production of: - Enzymes (for example: protease, pectinase, Invertase) - Acids (for example: citric acid) - Antibiotics (for example: Penicillin) - Proteins of pharmaceutical value Hormones (for example: Insulin.) Vaccines (for example. Hepatitis B virus (HBV) vaccine). 2024/2025 90 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 The pathogenicity of fungi ⮚ Cause human disease. ⮚ Fungi can destroy food and wooden structures. ⮚ Fungi cause numerous plant diseases ⮚ Fungal toxins Fungal diseases (Mycosis) o Cutaneous (Dermatophytes): Cause infections of the keratinized tissues (skin, hair, nails) e.g. Tinea infections Tinea corporis: Body ringworm (red, ring-shaped rash). Tinea pedis: Athlete’s foot (itchy, scaly skin between toes). Tinea capitis: Scalp ringworm, common in children. o Subcutaneous: under the skin (rare) o Systemic: infect lungs and internal organs e.g. Candidiasis. Candidiasis (Candida infections) Causative Agent: Candida species (most commonly Candida albicans). Types: o Oral thrush: White patches in the mouth, common in immunocompromised individuals or after antibiotic use. 2024/2025 91 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 o Vulvovaginal candidiasis: Vaginal itching, discharge. o Invasive candidiasis: Bloodstream infection, typically in hospitalized patients with weakened immune systems. Fungal toxins Mycotoxin: Group of compounds produced by some strains of certain fungi that cause illness or death when ingested by man or animals. Mycotoxicosis: diseases syndrome that result from the ingestion of mycotoxins 1. Aflatoxicosis: results from ingestion cereal grains and food stuffs such as maize, groundnuts contaminated with Aspergillus flavus aflatoxins - may cause Liver cancer 2. Ergot poisoning resulting from the ingestion of grain (wheat) contaminated with Claviceps purpurea. - with vomiting, diarrhea, thirst, fever, hallucinations, gangrene of the limbs and death 2024/2025 92 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Aspergillosis 2024/2025 93 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Which of the following is an example of fungal infections of the skin? A- Tinea B- Candida albicans C- Saccharomyces cerevisiae D- Hyphae Saccharomyces cerevisiae is useful in production of: Aflatoxicosis is caused by? A- Bread and HBV vaccine A- Candida albicans B- Insulin B- Saccharomyces cerevisiae C- Yoghurt C- Aspergillus flavus D- Both A & B D- Claviceps purpurea Saccharomyces cerevisiae is useful in production of: A- Bread and HBV vaccine B- Insulin C- Yoghurt D- Both A & B Which of the following represents Beneficial effects of the fungi? A- Ergotism B- Mycotoxicosis C- Systemic candida infection D- Bread industry 2024/2025 94 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Nosocomial Infections 2024/2025 95 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Nosocomial infection Nosocomial infections: Infections acquired in hospitals or healthcare settings also known as hospital-acquired infections (HAIs). To be considered nosocomial, the infection cannot be present at admission; rather, it must develop at least 48 hours after admission Importance: Nosocomial infections lead to: increased morbidity, mortality, prolonged hospital stays, and higher healthcare costs. Where do the microbes come from? 1-Endogenous sources: patients own flora 2- Exogenous sources: Cross infection from medical personnel Cross infection from patient to patient Hospital environment Inanimate objects 2024/2025 96 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Main routes of HAI transmission Direct Contact: Skin-to-skin contact with infected individuals or contaminated surfaces (e.g., MRSA). Indirect Contact: Via contaminated equipment or healthcare worker’s hands. Droplet Transmission: Through respiratory droplets (e.g., influenza, COVID-19). Airborne Transmission: Pathogens remain suspended in air (e.g., tuberculosis) Common vehicle transmission: Common source transmission applies when multiple people are exposed to and become ill from a common inanimate vehicle (contaminated food, water, medication, devices) Vector-borne: Spread through organisms like mosquitoes (less common in hospitals). 2024/2025 97 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Types of Nosocomial infection 1. Urinary Tract Infections (UTIs) Cause: Often linked to catheter use (Catheter-associated urinary tract infections – CAUTI). Common Pathogens: Escherichia coli, Enterococcus spp., Pseudomonas aeruginosa. Prevention: - Proper catheter insertion techniques. - Early removal of catheters when no longer needed. 2. Surgical Site Infections (SSIs) Cause: Bacterial contamination during or after surgery. 2024/2025 98 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Common Pathogens: Staphylococcus aureus, Streptococcus spp., Enterococcus spp. Prevention: - Proper surgical hand antisepsis. - Sterile techniques during surgery. - Antibiotic prophylaxis when indicated. 3. Ventilator-Associated Pneumonia (VAP) Cause: Pneumonia developing in patients on mechanical ventilation. Common Pathogens: Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter spp. Prevention: - Elevating the head of the bed. - Regular oral hygiene. - Early weaning off mechanical ventilation. 4. Bloodstream Infections (BSIs) Cause: Linked to the use of central venous catheters (Catheter- associated bloodstream infections – CLABSIs). 2024/2025 99 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Common Pathogens: Staphylococcus aureus (including MRSA), Candida spp., Enterococcus spp. Prevention: - Use of sterile technique during catheter insertion. - Regular cleaning of catheter sites and appropriate dressing changes. 5. Antibiotic-Resistant Infections Common Pathogens: Methicillin-resistant Staphylococcus aureus (MRSA), Vancomycin-resistant Enterococcus (VRE), Carbapenem-resistant Enterobacteriaceae (CRE). Prevention: - Judicious use of antibiotics (antibiotic stewardship). - Adherence to strict infection control practices. Preventing HAIs 1. Excluding sources of infection from the hospital environment ✓ Sterile instruments, dressings, medicaments, uncontaminated food ✓ Staff must undergo health screening before employment and regular health checks ✓ Appropriate immunization of staff 2024/2025 100 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 2- Interrupting the transmission of infection from source to susceptible host (breaking the chain of infection) ✓ Facilitation of aseptic behavior o Hand washing: the most important way of controlling HAI o Proper Use of Personal Protective Equipment (gloves, gowns, face mask, protective eyewear, face shield) ✓ proper installation of ventilation systems to control air-borne transmission of infection especially in operating theaters ✓ Patient isolation (protective or source isolation) 3. Enhancing the host’s ability to resist infection Boosting immunity with active or passive immunization Appropriate use of prophylactic antibiotics Care of invasive devices that breach the natural defenses 2024/2025 101 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Nursing Role in Infection Control  Patient Education: o Teach patients and families about the importance of hand hygiene and the proper use of Personal Protective Equipment. o Explain why certain precautions (e.g., isolation) are necessary to prevent infection spread.  Advocating for Safe Practices: o Ensure that infection control measures are being followed by all members of the healthcare team.  Monitoring for Early Signs of Infection: o Regularly assess patients for signs of infection and intervene early to prevent progression. 2024/2025 102 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 2024/2025 103 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 References 1 Cornelissen, C. N., Fisher, B. D., Harvey, R. A., & Harvey, R. A. (2013). Lippincott's illustrated reviews: Microbiology. 3rd edition, Philadelphia: Lippincott Williams & Wilkins. 2 Surinder Kumar (2016): Essentials of Microbiology. First Edition. Jaypee Brothers Medical Publishers 3 Levinson, W. (2014). Review of Medical microbiology & immunology Thirteenth Edition 4 Sherris & Ryan,s (2022): Medical microbiology. Eighteenth edotion, McGraw Hill 5. http://www.sciencedirect.com / http://www.google.com / http://www.pubmed.com Centers for Disease Control and Prevention. 2024/2025 104 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 Content Chapter Lecture topics Page no. 1 General Bacteriology 3 2 Genetics 25 3 Genetics 32 4 Systematic Bacteriology 50 5 Virology 67 6 Mycology 86 7 Nosocomial Infections 95 8 References 104 2024/2025 105 National Mansoura University Faculty of Nursing Microbiology (MansNurCMSc 105) Level 1 2024/2025 106