Microbiology and Parasitology PDF

Microbiology and Parasitology Microbiology Naming and Classifying MCO - Greek - Linnaeus established the system of - Mikros = small scientific nomenclature - Bios = life...

Microbiology and Parasitology Microbiology Naming and Classifying MCO - Greek - Linnaeus established the system of - Mikros = small scientific nomenclature - Bios = life - Each organism has 2 names: genus - Logia - is the study of microscopic and specific epithet organisms. - Are italicized or underlined - The genus is capitalized; the Microorganism specific epithet is lowercase - microbes - are organisms that are too small to Scientific Names be seen w/the unaided human eye. - Are “Latinized” and used worldwide - Germ refers to a rapidly growing cell - May be descriptive or honor a scientist Microbes in Our Lives - After the first use, scientific names A few are pathogenic (disease- may be abbreviated w/ the first letter causing) of the genus and the specific epithet: Decompose organic waste Escherichia coli and Are producers in the ecosystem by Staphylococcus aureus are photosynthesis found in the human body Produce industrial chemicals such E. coli is found in the large as ethanol and acetone intestine, and S. aureus is on Produce fermented foods such as skin vinegar, cheese, and bread Produce products used in Types of Microorganisms manufacturing and disease Bacteria treatment Archaea Fungi Knowledge of MCO allows human to: Protozoa Prevent food spoilage Algae Prevent disease occurrence Viruses Lead to aseptic techniques to Multicellular animal parasites prevent contamination in medicine and in microbiology laboratories. Classification of Microorganisms 3 Domains: *Aseptic - free from contamination 1. Bacteria caused by harmful bacteria, viruses, or other 2. Archaea microorganisms 3. Eukarya Protists Fungi Plants  Animals - Treatment w/ chemicals is chemotherapy Germ Theory of Disease - Chemotherapeutic agents used to I835: Agostino Bassi showed that a treat infectious disease can be silkworm disease was caused by a synthetic drugs or antibiotics fungus - Antibiotics are chemicals produced I865: Pasteur believed that another by bacteria and fungi or kill other silkworm disease was caused by a microbes protozoan I840s: Ignaz Semmelweis *Paul Ehrlich – chemotheraphy advocated handwashing to prevent *Synthetic drugs are created using man- transmission of puerperal fever from made chemicals rather than natural one obstetrical patient to another ingredients. (ex. aphrodisiac tea; NBOMes; I860s: Applying Pasteur’s work legal highs; party pills; synthetic cocaine; showing microbes are in the air, can synthetic cannabis; herbal ecstasy; plant spoil food, and cause animal fertilizer) diseases, Joseph Lister used a chemical disinfectant to prevent First Synthetic Drugs surgical wound infections - Quinine from tree bark was long I876: Robert Koch proved that a used to treat malaria bacterium causes anthrax and - Paul Ehrlich speculated about a provided the experimental steps, “magic bullet” that could destroy a Koch’s postulate, to prove that a pathogen w/o harming the host specific microbe causes a specific - I9I0: Ehrlich developed a synthetic disease arsenic drug, salvarsan, to treat syphilis *Anthrax is a serious infectious disease - I930s: sulfonamides were caused by gram-positive, rod-shaped synthesized bacteria known as Bacillus anthracis. *Syphilis is a bacterial infection usually Vaccination spread by sexual contact. - I796: Edward Jenner inoculated a person w/ cowpox virus, who was Antibiotics then protected from smallpox - Fortunate Accident - Vaccination is derived from vacca, - I928: Alexander Fleming for cow discovered the first antibiotic - The protection is called immunity - Fleming observed that Penicillium - Inoculated - Vaccinated fungus made an antibiotic, penicillin, that killed S. aureus The Birth of Modern Chemotherapy  - I940s: Penicillin was tested clinically bacterial DNA, and the and mass produced bacteria produced an animal protein Modern Developments in Microbiology - I94I: George Beadle and Edward - Bacteriology is the study of bacteria Tatum showed that genes encode a - Mycology is the study of fungi cell’s enzymes - Virology is the study of viruses - I944: Oswald Avery, Colin - Parasitology is the study of MacLeod, and Maclyn McCarty protozoa and parasitic worms showed that DNA is the hereditary - Immunology is the study of material immunity - I96I: Francois Jacob and Jacques ❖ Vaccines and interferons Monod discovered the role of are being investigated to mRNA in protein synthesis prevent and cure viral diseases Microbial Ecology - The use of immunology to identify - Bacteria recycle carbon, nutrients, some bacteria according to sulfur, and phosphorous that can be serotypes was proposed by used by plants and animals Rebecca Lancefield in I933 *Interferons are proteins that are part of your natural defenses. *A serotype or serovar is a distinct variation within a species of bacteria or virus or among immune cells of different individuals Bioremedation - Bacteria degrade organic matter in sewage Recombinant DNA Technology Microbial genetics: the study of - Bacteria degrade or detoxify how microbes inherit traits pollutants such as oil and mercury Molecular biology: the study of how DNA directs protein synthesis Genomics: the study of an organism’s genes; has provided new tools for classifying MCO Recombinant DNA: made from 2 different sources In the I960s, Paul Berg inserted animal DNA into  - They will grow on rocks, pipes, Biological Insecticides teeth, and medical implants - Microbes that are pathogenic to insects are alternatives to chemical pesticides in preventing insect damage to agricultural crops and disease transmission - Bacillus thuringiensis infections are fatal in many insects but Normal Microbiota harmless to other animals, including - Bacteria were once classified as humans, and to plants plants, giving rise to use of the term flora for microbes Biotechnology - This term has been replaced by - Biotechnology, the use of microbiota microbes to produce foods and - Microbes normally present in and on chemicals, is centuries old the human body are called normal - Recombinant DNA technology, a microbiota new technique for biotechnology, - Prevent growth of pathogens enables bacteria and fungi to - Produce growth factors, such as produce a variety of proteins, folic acid and vitamin K including vaccines and enzymes - Resistance is the ability of the body ❖ Missing or defective genes in human to ward off disease cells can be replaced in gene - Resistance factors include skin, therapy stomach acid, and antimicrobial ❖ Genetically modified bacteria are chemicals used to protect crops from insects and from freezing Infectious Diseases - When a pathogen overcomes the host’s resistance, disease results - Emerging infectious diseases (EIDs): new diseases and diseases increasing in incidence Drug Resistance The New Threat in Microbiology- (i.e. MRSA) Methicillin – resistance Staphylococcus aureus Biofilms 1950s: Penicillin resistance - Microbes attach to solid surfaces develop and grow into masses 1980s: Methicillin resistance  1990s: MRSA resistance to vancomycin reported VISA: vancomycin-intermediate- resistant S. aureus VRSA: vancomycin-resistant S. aureus *Methicillin-resistant Staphylococcus aureus (MRSA) is a cause of staph infection that is difficult to treat because of Structure of Bacteria resistance to some antibiotics. Bacteria are single-celled microorganisms with the absence of the *Methicillin antibiotic formerly used in the nucleus and other cell organelles; treatment of bacterial infections caused by classified as prokaryotic organisms. organisms of the genus Staphylococcus. Methicillin is a semisynthetic derivative of Versatile organisms, surviving in penicillin. extremely inhospitable conditions- called extremophiles- categorized into various Bacteria Definition types based on the types of environments - “Bacteria are unicellular organisms they inhabit: belonging to the prokaryotic group 1. Thermophiles - can survive at high where the organisms lack a few temperatures organelles and a true nucleus”. 2. Acidophiles - or acidophilic ❖ Prokaryotes organisms are those that thrive ❖ Peptidoglycan cell walls under highly acidic conditions ❖ Binary fission (usually at pH 2.0 or below). ❖ For energy, use organic & inorganic 3. Alkaliphiles - which grow optimally chemicals, or photosynthesis at pH value above 9.0, showing little or no growth at near neutral pH Bacteria Diagram values. - This represents the structure of 4. Osmophiles - adapted to bacteria with its different parts. The environments with high osmotic cell wall, plasmid, cytoplasm and pressures, such as high sugar flagella are clearly marked in the concentrations. Osmophiles are diagram. similar to halophiles (salt-loving organisms) 5. Barophiles - An organism that lives and thrives under high barometric pressure  6. Cryophiles - an organism that is able to survive and thrive in areas that have very low temperatures. 2nd - fascinating feature of bacteria is their protective cell wall, is made up of a special protein called peptidoglycan- is not found anywhere else in nature except in the cell walls of bacteria. ★ Ribosomes - sites of protein synthesis. They have an extra circular DNA called plasmid- which make some strains of bacteria resistant to antibiotics. Classification of Bacteria Bacteria can be classified into various categories based on their features and 3rd - protection layer called capsule. On the characteristics. outer layer, one or more flagella or pili is Shape attached, functions as a locomotory organ. Composition of the cell wall Pili can also help certain bacteria to attach Mode of respiration themselves to the host’s cells. They do not Mode of nutrition contain any cell organelle as in animal or plant cell except for ribosomes.  Classification of Bacteria 1. Cell wall: gram-positive bacteria is consisting of thick layers of peptidoglycan whereas gram- negative bacteria is consisting of thin layers of peptidoglycan. 2. During the gram staining procedure a gram-positive cell retains the purple-colored stain. But gram negative do not retain the purple colored stain. Classification of Bacteria 3. Gram-positive bacteria produce exotoxins, whereas gram-negative bacteria produce endotoxins. Gram-negative bacteria cause many infections in humans. Some common illness is indigestion, food poisoning, pneumonia, meningitis, etc. Some other infections also *Autotrophs are known as producers happen in the blood cells, because they are able to make their own bloodstream, wound infections, etc. food from raw materials and energy due to these bacteria. *Heterotrophs cannot make their own food, Reproduction in Bacteria so they must eat or absorb it/ consumers. - Bacteria follow an asexual mode of reproduction - binary fission. A single bacterium divides into two daughter cells. These are identical to the parent cell as well as to each other. Replication of DNA within parent bacterium marks the beginning of the fission. Cell elongates to form two daughter cells. - The rate and timing of reproduction depend upon the conditions like temperature and availability of nutrients. When there is a favourable condition, E.coli or Escherichia coli  produces about 2 million bacteria Production of antibiotics, which is every 7 hours. used in the treatment and prevention - Bacterial reproduction is strictly of bacterial infections – Soil bacteria asexual, but it can undergo sexual reproduction in very rare cases. Harmful Bacteria - Genetic recombination in bacteria There are bacteria that can cause a has the potential to occur through multitude of illnesses. They are conjugation, transformation, or responsible for many of infectious transduction. In such cases, the diseases like pneumonia, bacteria may become resistant to tuberculosis, diphtheria, syphilis, antibiotics since there is variation in tooth decay. Their effects can be the genetic material (as opposed to rectified by taking antibiotics and asexual reproduction where the prescribed medication. same genetic material is present in Precaution is much more effective. generations) Most of these disease-causing bacteria can be eliminated by sterilizing or disinfecting exposed surfaces, instruments, tools and other utilities. These methods include- application of heat, disinfectants, UV radiations, pasteurization, boiling, etc. Archaea Useful Bacteria Not all bacteria are harmful to humans. ❖ Archaea, (domain Archaea), any of a There are some bacteria which are beneficial group of single-celled prokaryotic organisms (organisms whose cells in different ways. lack a defined nucleus) that have Few benefits of bacteria: distinct molecular characteristics Convert milk into curd – separating them from bacteria (more prominent group of prokaryotes) as Lactobacillus or lactic acid bacteria well as from eukaryotes (organisms, Ferment food products – including plants and animals, whose cells contain a defined nucleus). Streptococcus and Bacillus ❖ Archaea is derived from the Greek Help in digestion and improving the body’s immunity system – word archaios, meaning “ancient” or Actinobacteria, Bacteroidetes, “primitive.” ❖ Members of the archaea include: Firmicutes, Proteobacteria Pyrolobus fumarii, which holds the upper temperature limit for life at 113  °C (235 °F) and was found living in hydrothermal vents; species of Picrophilus, which were isolated from acidic soils in Japan and are the most acid-tolerant organisms known—capable of growth at around pH 0; and the methanogens, which produce methane gas as a metabolic by- product and are found in anaerobic environments, such as in marshes, hot springs, and the guts of animals, Eukaryote including humans. - [u-kar´e-ōt] an organism of the Eucaryotae, whose cells ❖ Prokaryotic (eukaryotic cells) have a true ❖ Lack peptidoglycan nucleus that is bounded by a nuclear ❖ Live in extreme environments: membrane, contains the ➔ Methanogens chromosomes, and divides by ➔ Extreme halophiles mitosis. ➔ Extreme thermophiles - Eukaryotic cells also contain membrane-bound organelles, such Members of the archaea include: as mitochondria, chloroplasts, Pyrolobus fumarii, which holds the lysosomes, and the Golgi upper temperature limit for life at 113 apparatus. Plants and animals, °C (235 °F) and was found living in protozoa, fungi, and algae (except hydrothermal vents blue-green algae) are eukaryotes. f Picrophilus, which were isolated Other organisms (the bacteria) are from acidic soils in Japan and are prokaryotes. the most acid-tolerant organisms known—capable of growth at 1. A cell containing a membrane- around pH 0; and the methanogens, bound nucleus with chromosomes which produce archaea of DNA and proteins, generally large (10-100 mcm), with cell division *Archaea are found in a diverse range of involving a form of mitosis in which extreme environments, including the salt mitotic spindles are involved; deposits on the shores of the Dead Sea. mitochondria are present, in photosynthetic species, plastids are found; undulipodia (cilia or flagella) are of the complex organization of microtubules and various proteins.  Possession of an eukaryote type of they have been separated from cell characterizes the four kingdoms plants. above the Monera or prokaryote - In addition, fungi are clearly level of complexity: Protoctista, distinguished from all other living Fungi, Plantae, and Animalia, organisms, including animals, by combined into the superkingdom their principal modes of vegetative Eukaryotae. growth and nutrient intake. Fungi grow from the tips of filaments 2. Common name for members of the (hyphae) that make up the bodies of Eukaryotae. Synonym(s): eucaryote the organisms (mycelia), and they digest organic matter externally before absorbing it into their mycelia. While mushrooms and toadstools (poisonous mushrooms) means the most numerous or economically significant fungi, most easily recognized. The Latin word for mushroom, fungus (plural fungi), has come to stand for the whole group. Fungus Similarly, the study of fungi is known - (plural: fungi or funguses ) is any as mycology—a broad application of member of the group of eukaryotic the Greek word for mushroom, organisms that includes mykēs. Fungi other than mushrooms microorganisms such as yeasts and are sometimes collectively called molds, as well as the mushrooms. molds, although this term is better - These organisms are classified as a restricted to fungi of the sort kingdom, which is separate from the represented by bread mold. other eukaryotic life kingdoms of A characteristic that places fungi in a plants and animals. different kingdom from plants, - Fungi are free-living in soil or water; bacteria, and some protists is chitin others form parasitic or symbiotic in their cell walls. Similar to animals, relationships with plants or animals. fungi are heterotrophs; they acquire - Fungi are eukaryotic organisms; their food by absorbing dissolved i.e., their cells contain membrane- molecules, typically by secreting bound organelles and clearly defined digestive enzymes into their nuclei, included in the plant kingdom; environment. Fungi do not because fungi lack chlorophyll and photosynthesize. Growth is their are distinguished by unique means of mobility, except for spores structural and physiological features  (a few of which are flagellated), which ★ Chitin cell walls may travel through the air or water. ★ Use organic chemicals for energy ★ Molds & mushrooms are Fungi are the principal multicellular, consisting of masses of decomposers in ecological mycelia, which are composed of systems. filaments called hyphae Myxomycetes (slime molds) and ★ Yeasts are unicellular oomycetes (water molds). The study of fungi is known as Examples: mycology (from the Greek μύκης 1. panther cap mushrooms mykes, mushroom). (mushroom Panther cap Amanita In the past, mycology was regarded pantherina). Closely related to the as a branch of botany, although it is death cap mushroom (Amanita now known fungi are genetically phalloides), the panther cap is highly more closely related to animals than poisonous. to plants. 2. The fly agaric (Amanita muscaria) is a Most fungi are inconspicuous poisonous fungus. because of the small size of their 3. Sven Samelius structures, and their cryptic lifestyles 4. artist's conk Artist's conk in soil or on dead matter. (Ganoderma applanatum), a Fungi include symbionts of plants, bracket fungi. Distributed worldwide, animals, or other fungi and also the artist's conk is a wood-decaying parasites. They may become fungus that primarily grows on dead noticeable when fruiting, either as or dying trees. mushrooms or as molds. Fungi perform an essential role in the Protozoa decomposition of organic matter and - (prōt″ ă-zō′ ă) [ proto- + -zoa] have fundamental roles in nutrient - The phylum of the kingdom Protista cycling and exchange in the that includes unicellular, animal-like environment. microorganisms. They have long been used as a - Many protozoa are saprophytes direct source of human food, in the that live on dead matter in water and form of mushrooms and truffles; as a soil. Many parasitic protozoa infect leavening agent for bread; and in the only humans without adequate fermentation of various food immunological defenses although a products, such as wine, beer, and few infect the immunocompetent. soy sauce. Infections are spread by the fecal- oral route, through ingestion of food Fungi: or water contaminated with cysts or ★ Eukaryotes spores, or by the bite of a mosquito  or other insect that has previously ❖ Protozoa: Primitive, single-celled bitten an infected person. (unicellular) or acellular organisms - Common protozoan infections that are found in moist soil or water. include malaria (Plasmodium vivax, They tend to exist as parasites, living P. malariae); gastroenteritis off other life forms. microscopic (Entamoeba histolytica, Giardia animals able to move by amoeboid lamblia); leishmaniasis, an action or by means of CILIA or whip- inflammatory skin or visceral disease like appendages (flagella). (Leishmania species); sleeping ❖ Many protozoa are parasitic on sickness (Trypanosoma brucei humans and are of medical gambiense, T. b. rhodiense); and importance. They are motile and can vaginal infections (Trichomonas move by: vaginalis). Pneumocystis jiroveci, ❖ Cilia - tiny hair like structures that previously classified as a protozoan, cover the outside of the microbe. is now categorized as a fungus. They beat in a regular continuous - Opportunistic protozoan pattern like flexible oars. infections caused by ❖ Flagella - long thread-like structures Cryptosporidium parvum and that extend from the cell surface. Toxoplasma gondii are seen in Move in a whip-like motion that patients who are immunosuppressed produces waves that propel the by disease or drug therapy. microbe around. ❖ Amoeboid movement - the organism moves by sending out pseudopodia, temporary protrusions that fill with cytoplasm that flows from the body of the cell. Eukaryotes Absorb or ingest organic chemicals May be motile via pseudopods, cilia, or flagella Algae - singular alga, members of a group of predominantly aquatic photosynthetic organisms of the kingdom Protista. - Algae have many types of life cycles, and they range in size from microscopic Micromonas species to giant kelps that reach 60 metres (200 feet) in length. - Their photosynthetic pigments are more varied than those of plants, and their cells have features not found among plants and animals. - In addition to their ecological roles as oxygen producers and as the food base for almost all aquatic life, algae are economically important as a source of crude oil and as sources of food and a number of pharmaceutical and industrial products for humans. - The taxonomy of algae is contentious and subject to rapid change as new molecular information is discovered. The study of algae is called phycology, and a  person who studies algae is a phycologist. - Algae as seen through a microscope. - Red algae is the most common form of marine algae. Uses ❖ A number of types of seaweed, especially among the red algae, can be eaten. Seaweeds also provide a number of important food additives, and agar — a type of gel used for culturing microorganisms. ❖ Another potential use is in the production of biofuels. The organisms are fast growing and undemanding in terms of conditions and nutritional requirements, and so they can provide a cheap and efficient way of accumulating biomass for fuel. ➔ Eukaryotes ➔ Cellulose cell walls ➔ Use photosynthesis for energy ➔ Produce molecular oxygen & organic compounds Viruses: Acellular Consist of DNA or RNA core Core is surrounded by a protein coat Coat may be enclosed in a lipid envelope Are replicated only when they are in a living host cell Multicellular Animal Parasites: Eukaryotes Multicellular Animals Parasitic flatworms & roundworms are called helminths Microscopic stages in life cycles  Protozoa - Unicellular, animal-like organism - Lives on a dead matter - Infects person with low immune system, may pass through fecal- oral route, ingestion of contaminated substance/food, bite of insects that has bitten infected person - Absorb/ingest organic chemicals - Motile via pseudopods, cilia, flagella Algae - Eukaryotes Bacteria - Cellulose cell walls - Prokaryotic - Autotrophs - Peptidoglycan cell wall - Produce molecular oxygen and - Binary fission organic compounds Archaea - Prokaryotic / single-celled without defined nucleus - Lack peptidoglycan - Lives in extreme environment Eukaryote - With defined nucleus/ plant and animal cell - Undergoes mitosis/ cell division Prokaryotes - Membrane-bound with nucleus Fungi - Yeast(unicellular), molds& mushroom(multicellular) - Eukaryotic - Chitin cell walls (major constituents of fungi’s cell walls) - Use organic chemicals for energy