Bacteriology Lecture Week 1 PDF

CLINICAL BACTERIOLOGY LECTURE / SECOND SEMESTER Mr. Glenford D. Monzon, RMT LESSON 1: FUNDAMENTALS OF BACTERIOLOGY AND BACTERIAL CELL TOPIC 1: HISTORY John Needham’s Experiment Microbiology Branch of biology that deals with mi...

CLINICAL BACTERIOLOGY LECTURE / SECOND SEMESTER Mr. Glenford D. Monzon, RMT LESSON 1: FUNDAMENTALS OF BACTERIOLOGY AND BACTERIAL CELL TOPIC 1: HISTORY John Needham’s Experiment Microbiology Branch of biology that deals with microorganisms and their effects on their effect on other living organisms. History of Microbiology Lazzaro Spallanzani Experiment Greeks: Abiogenesis Abiogenesis - production of life from nonliving organisms. 2nd Century: Varro Invisible living creatures 1546: Fracastorius “Seminaria” / “seeds” "Seminaria" - germs 1665: Robert Hooke Cells 1673: Anton Van Leeuwenhoek Heat killed the microbes, and, since the Animalcules flasks were sealed, microbes did not Father of Microbiology reappear. 1668: Francesco Redi Refuted spontaneous generation Golden Age of Microbiology: (1857-1914) 1745: John Needham Microbes as the real ethioloical agents of Supported Abiogenesis disease 1765: Lazzaro Spallanzani Rapid discovery of microbes causing Refured Needham’s Experiment diseases 1838: Rudold Virchow, Theodore Schwann, Discovery of treatments and aseptic Matthias Schleiden techniques Cell Theory Role of immunology in preventing and 1861: Louis Pasteur curing diseases Father of Modern Microbiology Golden age of microbiology Germ Theory of Disease Proof That Microbes Causes Diseases Pasteurization Fracastorius: Phenomenon of Contagious infection 1835 - Agostino Bassi De Lodi: Fungi causes silkworm disease 1847 - Ignaz Semmelweiz: Introduced hand washing Louis Pasteur: Germ Theory of Diseases Joseph Lister: Aseptic Technique ⋄ Aseptic technique using carbolic acid / phenol Robert Koch: Koch’s Postulates Jhen Anne D. Abana | 1  ⋄ Significant - framework for Modern Developments in Microbiology germ theory of diseases Immunology Using Jenner’s experiment, Pasteur Koch's Postulate Experiment developed vaccines against fowl cholera, anthrax, and rabies 1933: Rebecca Lancefield ⋄ Proposed that streptococci be classified according to serotypes Molecular Developments in Microbiology Molecular genetics 1960: Paul Berg inserted animal DNA into bacterial DNA and the bacteria produced animal protein Other Notable Discovery 1901 Von Behring Diptheria antitoxin 1902 Ronald Ross Malaria Transmission 1905 Robert Koch TB bacterium 1908 Metchnifkoff Phagocytes 1952 Wakman Streptomycin 1969 Delbruck, Viral replication Hershey, Luria Koch's contribution 1987 Susumu Antibody genetics Aseptic technique Tonegawa Pure culture technique 1997 Stanley Prusiner Prions Stains The Birth of Chemotherapy Chemotherapy Treatment of diseases using chemical substances Synthetic drugs 1910: Salvarsan 1930: Sulfonomides Quinine: from a tree bark Antibiotics Penicillin: from Penicillium chrysogenum Living organisms Paul Erhlich Wanted to find “magic bullet” an agent that would kill the disease aent without hurting the patient Developed Salvarsan for syphilis Jhen Anne D. Abana | 2  TOPIC 2: TYPES OF MICROORGANISMS, NOMENCLATURE, AND CLASSIFICATION Bacteria ⋄ Prokaryotes ⋄ Peptidoglycan walls Pure microbiology ⋄ Binary fission Bacteriology - Bacteria ⋄ For energy, use organic chemicals, Mycology - Fungi inorganic chemicals, or Nematology - Nematodes or roundworms photosynthesis Parasitology - Protozoa and Parasitic worms Archea ⋄ Prokaryotic Phycology - Algae ⋄ Lack of peptidoglycan Protozoology - Protozoa ⋄ Live in extreme environment Virology - Virus ⋄ Include: ⊳ Methanogens: produce methane Major Fields of Applied Microbiology as a waste product from Medical microbiology respiration Aquatic microbiology ⊳ Extreme halophiles: (halo = salt; Food microbiology philic = loving) live in extremely salty environments Agricultural microbiology ⊳ Extreme thermophiles: (therm = Industrial microbiology heat) live in hot sulfurous water Geochemical microbiology Fungi ⋄ Eukaryotes Microbes and Human Welfare ⋄ Chitin cells walls Microbial Ecology ⋄ Use organic chemicals for energy Bacteria recycle carbon, nutrients, and ⋄ Mold and mushrooms are multicellular phosphorus that can be used by plants and consisting masses of mycelia, which are composed of filaments called animals hyphae Bacteria degrade organic matter in sewage ⋄ Yeasts are unicellular Bacteria may degrade or detoxify pollutants such as oil and mercury Protozoa ⋄ Eukaryotes Bacteria can be used as alternative ⋄ Absorb or ingest organic chemicals insecticides/pesticide t prevent damage to ⋄ May be motile via pseudopods, cilla, agricultural crops/disease transmission or flagella (Bacillus thuringiensis) Algae ⋄ Eukaryotes ⋄ Cellulose cell walls Modern Biotechnology and Genetic Engineering ⋄ Use photosynthesis for energy Biotechnology - The use of microbes to ⋄ Produce molecular oxygen and produce food and chemicals organic compounds Genetic Enineering is a new technique for biotechnology. It allows microbes (bacteria Viruses ⋄ Acellular ⋄ Consist of DNA or RNA core and fungi) to produce a variety of proteins ⋄ Core is surrounded by a protein coat including vaccines and enzymes ⋄ Coat may be enclosed in a lipid Gene Therapy - Missing or defective genes envelope can be replaced ⋄ Viruses are replicate only when they Genetically Modified bacteria are used to are living in a living host cell protect crops or enhance the flavor, texture, and shelf-life of some agricultural Helminths ⋄ Eukaryote products ⋄ Multicellular animals ⋄ Parasitic flatworms and round worms are called helminths ⋄ Microscopic stages in life cycle Jhen Anne D. Abana | 3 Naming and Classifying Microorganisms Linnaeus established the system of scientific nomenclature Classification is the organixzation of microorganisms that share similar morphologic, physiologic, and genetic traits into specific groups or taco Five kingdom system (Animalia, Mycetae, Plantae, Protista, Prokaryotae) Three domain system Nomenclature Each organism has two names: the genus and specific epithet Are italized or underlined. The genus is capitalized, and the specific epithet is lower case E.g. Escherichia(genus) coli(specie) Are “Latinized” and used worldwide After the first use, scientific names may be abbreviated with the first letter of the genus and the specific epithet: Staphylococcus aureus and Escherichia coli are found in the human, S. aureus is on skin and E. coli, in the large intestine Scietific Names May be descriptive or in honor of a scientist Staphylococcus aureus: clustered arrangement, golden colonies Escherichia coli: in honor of Theodor Erhlich, habitat (colon) Neisseria gonorrhea: In honor of Albert Neisser Identification Process of delineating microorganism’s key feature Genotypic characteristics Phenotypic characteristics Major Characteristics Used in Taxonomy Classical characteristics Useful in routine identification nad phylogenetic information-morphology, physiology, metabolism, ecology, and genetic analysis Molecular characteristics Based on the study of nucleic acid composition and proteins Jhen Anne D. Abana | 4 TOPIC 3: BACTERIAL CELLS: STRUCTURE, METABOLISM, ⋄ Sometimes, Staphylococcus spp. also AND REPRODUCTION form in tetrads d. Sarcinae Prokaryote VS Eukaryote ⋄ Cocci that divide in three planes and remain in groups / in cube-like groups Prokaryote Eukarote e. Staphylococci One circular Paired chromosomes, in ⋄ Divide in multiple planes and form chromosome, not in a nuclear membrane grape-like clusters membrane ⋄ Ex. Staphylococcus aureus (gram +) Bacilli (rod-shaped) No histones Histones a. Single bacillus No organelles Organelles ⋄ Single rod ⋄ Most bacilli form as single rods Peptidoglycan cell wall Polysaccharide cell walls ⋄ Ex. Bacillus cereus (gram +) b. Diplobacillus Binary fission Mitotic spindle ⋄ Appear in pairs after division c. Streptobacillus Bacterial Morphology ⋄ Appear in chains after division Prokaryotic d. Coccobacillus Average size: 0.4 - 2 um ⋄ Fat and short Smallest: Mycoplasma ⋄ Look like cocci and bacillus Largest: Bacillus Spiral bacteria Unusual shapes a. Vibrio Star -shaped Stella ⋄ Curved spirals Square Haloarcula ⋄ Comma-shaped Most bacteria are monomorphic (single ⋄ Ex. Vibrio cholerae (gram -) form) b. Spirillum A few are pleomorphic (different form) ⋄ Helical-shaped and fairly rigid bodies ⋄ Flagella are externally located c. Spirochete ⋄ Have flexible bodies ⋄ Are flexible because of axial filaments/endo flagella (wound around their bodies) ⋄ Move in a corkscrew manner Cocci (spherical, round, ovoid) a. Diplococci ⋄ Composed of two cocci (remain in pairs after dividing) ⋄ Ex. Neisseria gonorrhoeae b. Streptococci ⋄ Cocci that are in chain after dividing ⋄ Ex. Streptococcus pneumoniae (gram +) and Streptococcus pyogenes (gram +) c. Tetrad ⋄ Divide into two planes and remain in groups of 4 Jhen Anne D. Abana | 5 Important Components of a Bacteria Plasma Membrane Capsule Phospolipid bilayer with embedded proteins Cell wall Does not contain sterols (except Plasma membrane mycoplasma) Pili Osmotic barrier, site of electron transport Endospores chain Flagella Selective permeability Inclusions bodies Nucleus Movement Across Membrane Ribosomes Passive Simple Diffusion Ribosomes and Nucleus Facilitated Diffusion Ribosomes: protein synthesis ⋄ Protein carriers Nucloid: DNA in the bacterial cell is Osmosis generally located at the center ⋄ Protein carriers Cell wall Active Also known as “murein layer” or Requires ATP and transporter chain “peptidoglycan layer” Rigid layer that maintains cell shape Glycocalyx VS Capsule Point of anchorage for flagella. Site of attachment Glococalyx Capsule Determines the staining characteristics of the bacteria Outside cell wall Peptidoglycan Polymer of disaccharide Usually sticky (slime N-acetylglucosamine (NAG) and layer) N-acetylmuramic acid (NAM) Linked by peptides Neatly organized Unorganized and loose Extracellular Prevents phagocytosis polysaccharide allows Gram Positive Gram Negative cell to attach Outer cell layer Thicker cell wall Thinner cell wall Lipid A: Capsule (+) endotoxin Bacillus anthracis Klebsiella pneume.onae Cell wall Lipoteichoic Lipopolysacchar Haemophilus influenzae structure acid ide (washed out during staining) Streptococcus pneumoniae Neisseria meningiditis Periplasm has nutrients Flagella Outside the cell wall Made of chains of flagellin Atypical Cell Walls Attached to a protein hook Acid fast cell walls Anchored to the wall and membrane by Contains mycolic acid the basal body Mycoplasma and Ureaplasma Rotate flagella to run or tumble Lacks of cell wall Move toad or away from stimuli (taxis) Contains sterols in plasma Flagella proteins are H antigens (e.g., E.coli membrane O157:H7) Archea Cell appendage used for locomotion Wall less or walls of pseudomurein Jhen Anne D. Abana | 6  Many bacilli and spiral are motile while true Resistant to dessication, heat, and motility is seldom in cocci chemicals Motility is best seen in room temperature Bacillus, Clostridium Brownian motion Sporulation Movement of nonmotile organism Endospore formation due to movement of molecules Germination surrounding them Return to vegetative state Type of movement Bacteria Gliding motion Capnocytophaga Darting motion Campylobacter jejuni Tumbling motion Listeria monocytogenes Twitching motiom Kingella kingale Metachromatic Granules / Inclusion Bodies Shooting star motion Vibrio cholerae Metachromatic Phosphate reserves Corkscrew motion Spirochetes Granules Flagellar Arrangement Polysaccharide Monotrichous granules Flagellum located on a single pole Energy reserves Lipid inclusion Lophotrichous Flagella located on one pole Sulfur granules Peritrichous Flagella surround thebacteria Carboxysomes Ribulose Amphitrichous 1,5-diphosphate Flagella on both poles of the carboxylase (CO2 bacteria fixation) Ways to demonstrate motility Use of flagellar stain Gas vauoles Proteins covered Hanging drop cylinders Semi solid media Manetosomes Iron oxide (destroys Axial Filaments H2O2) Endoflagella In spirochetes Barterial Metabolism Anchored at one end of a cell Energy is needed by the bacterium and Rotation causes cell to move generated from various metabolic pathway Important to study to help micro biologist PIli and Fimbriae identify phenotypic markers Fimbriae allow attachment to surfaces Utilization of various substrate as carbon Pili are used to transfer DNA from one cell to source another Production of specific products Commonly found in Gram Negative organisms like Production of an acid/alkaline pH in E. coli, N. gonorrhoeae, and Pseudomonas test medium Fermentation VS Respiration Endospores Fermentation: does not requires oxygen Resting cells Respiration: requires oxygen Jhen Anne D. Abana | 7 Pyruvic Utilization Benzpyrene Fermentative ⋄ From smoke and soot Alcoholic Fermentation (ethanol) Aflatoxin Homolactic Fermentation Radiation ⋄ lactic acid Heterolactic Fermentation Mechanism of Mutation ⋄ lactic acid + CO2, ROH, Formic Substitution of a nucleotide acid, and acetic acid ○ Base substitution (point mutation) Propionic Acid Fermentation involves the changing of single base ⋄ propionic acid in the DNA sequence Mixed Acid Fermentation ○ Transition ⋄ Lactic / Acetic / Succinic / Formic If one purine (A or G) or Acid pyrimidine (C or T) is Butanediol Fermentation replaced by the other ⋄ Acetoin ○ Transversion Butyric Acid Fermentation If a purine is replaced by ⋄ Butyric+acetic, CO2, H2 pyrimidine or vice versa Oxidative Deletion or addition of nucleotides: during Kreb Cycle and ETC DNA replication ○ Insertional mutation TOPIC 4: BACTERIAL GENETICS When a transposon (jumping gene) insert itself into a gene, Genetic Exchange and Diversity which leads to disruption of Mutation gene Alteration in the original nucleotide sequence of a gene Significance of Mutation Effects of mutation varies Discovery of a mutation in a gene can help Genetic Recombination in identifying the function of that gene Altered genotypes to DNA Mutations can be induced at a desired recombination region to create a suitable mutant, A donor cell exchanges a DNA especially to produce vaccines segment to a recipient cell Spontaneous mutation can result in (homologenous recombination) emergence of antibiotic resistance in ⋄ Mainly facilitated by recA protein bacteria Mutation Mutations can result in change in Latin word “to change” - HUgo de Vries phenotype such as: Are heritable changes in genotype that can Appearance of noel antigen (Ag) occur spontaneously or be induced by Alteration in physiological properties chemical or physical treatments Change in colony morphology, Wild type nutritional requirements, and Mutants biochemical reactions Mutagenesis: process of mutation Growth characteristics Mutagen Virulence Mutagen Host range Chemicals Nitrous Acid Gene Recombination ⋄ Which laters adenine to pair with Genes are transferred or exchanged cytosine instead of thymine between similar regions on 2 DNA molecules Acridine dyes Crossin over ⋄ Nucleoside analogs that are similar in structure to nitrgenous bases Jhen Anne D. Abana | 8 Advantages of Bacteria in Genetic Study 1. They are haploid (no masking) 2. New generation is produces every 20 minutes 3. Easy to grow in enormous numbers 4. Individual members of these large populations are genetically identical (or very nearly so) Mechanism of Gene Transfer Transformation The process where bacteria manage to “uptake” or bring in a piece of external DNA Once the DNA has been taken up, it can be incorporated into the bacterial genome by recombination Cells that can be external DNA are called competent E.g., S. pneumonae, N. gonorrheae, H. influenzae Transduction Transfer of bacterial genes by a bacteriophage (a bacterial virus) from one cell to another Process by which DNA is transferred from one bacterium to another by a virus ⋄ Bacteriophage: virus that infect bacteria Conjugation The process in which DNA is transferred from bacterial donor cell to a recipient cell by cell-to-cell contact The ability to transfer DNA by conjugation is dependent on the presence of a cytoplasmic entity termed the fertility factor, or F F+ and F- Jhen Anne D. Abana | 9