Intro to Microbiology Lecture Notes Fall 2023 PDF

Intro to Microbiology TA: Justin Hedlund Fall 2023 Vet Prep RUSVM Email: [email protected] presentation title 1  Learning objectives 2023 Bacteriology 2  Key bacterial characteristics: Prokaryotes VS. Eukaryo...

Intro to Microbiology TA: Justin Hedlund Fall 2023 Vet Prep RUSVM Email: [email protected] presentation title 1  Learning objectives 2023 Bacteriology 2  Key bacterial characteristics: Prokaryotes VS. Eukaryotes Prokaryotes: Eukaryotes: (NOT BACTERIA) Unicellular Nucleus present No nucleus Larger in size or multicellular Single circular chromosome Multiple chromosomes No cytoskeleton Cytoskeleton present Division via binary fission Division via mitosis Chemically complex cell wall If cell wall is present its is chemically Asexual reproduction simple Meiosis for reproduction 2023 Bacteriology 3  Bacterial Cell Wall Mycoplasma (no cell wall, only exception) Functions: Protect against mechanical damage and osmotic lysis Allows non-selective transport Differences between structure and chemical composition between species provides differences in pathogenicity and staining properties Peptidoglycan: A chain of alternating NAG and NAM subunits crosslinked with short peptides. (N-acetylglucosamine, N-acetylmuramic acid) This is a polymer that is unique to the prokaryotic cell wall Gives the cell wall rigidity Differences between structure and chemical composition between species provides differences in pathogenicity and staining properties 2023 Bacteriology 4  Gram-positive Bacteria Cell Wall Have multilayered, thick peptidoglycan layer (which is why it can hold onto the crystal violet) Only one plasma membrane Highly resistance to physical disruption and drying (will NOT dry) Highly susceptible to ionic detergents (detergents DO work) Contain teichoic acids (linked with peptidoglycan) and lipoteichoic acids (linked with plasma membrane) These play a role in colonization, infection, and immune evasion Protect the bacteria against harmful molecules and stress form environment Strongly antigenic meaning it causes an immune response 2023 Bacteriology 5  Gram-negative Bacteria Cell Wall Thin single layer of peptidoglycan (why crystal violet can wash out with alcohol) Has an inner and outer plasma membrane with periplasmic space (periplasm) Not very resistant to physical disruption and drying (will dry out) Not very susceptible to ionic detergents (ionic detergents DON’T work) Have lipopolysaccharides (LPS) Virulence factor The lipid A components of the LPS is the endotoxin that will activate the immune system and cause harmful effects on its host. They are released upon cell disruption The polysaccharide component causes antigenicity of bacteria 2023 Bacteriology 6  Gram-staining Technique Differentiates bacteria by their chemical and physical properties of the walls by detecting their peptidoglycan Gram-positive shows up purple (‘absorbs’ the crystal violet dye) Gram-negative shows up pink (only ‘absorbs’ the safranin) Technique: Apply crystal violet (purple dye) Apply iodine (mordant) Wash with alcohol (decolorization) Apply safranin (counterstain) 2023 Bacteriology 7  Mycobacteria Cell Wall Has a thick waxy hydrophobic cell wall Many mycolic acids (don’t allow decolorization) Acid-fast staining aka Zeihl-Neelsen staining is used to visualize it under microscopy, for Mycobacteria Technique: Apply carbolfuschin (primary stain) Apply heat (mordant) Apply acid alcohol (decolorizer) Apply methylene blue (counterstain) 2023 Bacteriology 8  EXCEPTION: Mycoplasma Mycoplasma does not contain a cell wall; their plasma membranes contain sterols for rigidity instead. Side note: This is different then mycobacteria I know people would finally understood there is a difference in 3rd semester. Don’t be that person. 2023 Bacteriology 9  Plasma Membrane Composed of phospholipids and proteins – no sterols. Flexible structures with hydrophobic outside and hydrophobic inside faces Functions: Active transport of nutrient Eliminates waste metabolites Electron transport for bacterial respiration Phosphorylation Role with biosynthesis of DNA, cell wall polymers and lipids 2023 Bacteriology 10  Plasma membrane cont. 3 types of transport systems: (important) Facilitated diffusion Active transport Group translocation Mesosomes are an invagination of the plasma membrane into the cytoplasm – not found in all bacteria -Not an organelle! (Mesosomes are FYI for Dr. G) Left it in here because I think there is a practice question about 2023 Bacteriology 11  Genetic material locations Nucleoid is the region in the cell where the nuclear material is currently occupying. Single haploid circular chromosome Double stranded DNA Extensively folded chromosome Plasmids are small circular pieces of DNA that are capable of replication independent of the nucleoid DNA Carries genes that are associated with disease → virulence factors Carries genes to survive in the presence of antibiotics or toxic compounds → resistance genes 2023 Bacteriology 12  Flagella Located on bacterial surface for the function of locomotion or motility Structure: filament, hook, and basal body Flagellar arrangement is dependent of the number of flagella and the position in which they’re on the cell wall. Monotrichous → one flagella only and its on one of the ends of the cell Amphitrichous → one flagella on either side of cell Lophotrichous → multiple flagella on one side of cell (ponytail) Peritrichous → many flagella all over the surface of the cell Composed by the protein flagellin Endoflagella are flagella located in the periplasmic space which allow for a corkscrew-like motility (e.g. spirochetes) 2023 Bacteriology 13  Pili/Fimbriae Fine, straight, hair-like appendages attached to the cell wall More common in gram-negative bacterial Composed of the protein pilin Functions for adhesion to host tissue and can contribute to antigenicity The cause of E.coli K88 in neonatal piglets and K99 in neonatal calves 2023 Bacteriology 14  Capsule Aka Glycocalyx which is an extracellular polymeric matrix made up mostly of polysaccharides. Only found in some bacterial species Functions for nutrient reserve, protection from adverse conditions in environment, adherence to host cell surface, inference with phagocytosis. 2023 Bacteriology 15  Endospores Bacteria will be in a cryptobiotic state of dormancy, and this endospore is the most durable type of cell in nature. It ensures the survival of the cell during adverse environmental condition for long periods of time The bacterial will eventually be released as free spores. Produces by 2 genera → clostridium and bacillus 2023 Bacteriology 16  Endospores: Sporulation summary Step 1: DNA replicates and elongates Step 2: septum forms on one side of the cell to separate a forespore from the mother cell → they both get a chromosome Step 3: Mother cell will engulf the forespore giving the forespore a second membrane Step 4: mother cell chromosomes disintegrate Step 5: forespore develops cortex layer between their original membrane and their mother cells membrane they gained. Step 6: synthesize materials into their spore coat The cell will remain dormant until time to be released by its mother cell where then after it will germinate into a mature cell. 2023 Bacteriology 17  Bacterial Morphology Know differences between cocci, streptococci, diplococci, encapsulated diplococci, staphylococci, and tetrad. Know differences between bacillus, diplobacilli, pallisades, and streptobacilli. Know differences between corkscrew, filamentous, spirochete Know differences between club rod, helical form, and budding/appendaged bacteria (FYI) Be able to identify these in microscopy 2023 Bacteriology 18  Bacterial Metabolism, Phylogeny, and Pathogenesis Understand: Bacterial growth, growth curve, and enumeration of bacteria Polyphasic taxonomy Know terminology and what they mean in relation to metabolism and pathogenesis Know concepts of infectious diseases and bacterial pathogenesis Know and understand the time period in the course of infectious disease 2023 Bacteriology 19  Factors Required for Bacterial Growth Sources of metabolic energy: Gaseous requirements: O2 and CO2 Environmental factors: Aerobic respiration: requires Aerobes: unable to grow without oxygen Nutrients oxygen for growth Facultative anaerobes: can grow under pH – most pathogenic bacteria Anaerobic respiration: Uses both aerobic and anaerobic conditions have optimal growth around 7.2- other electron acceptors than 7.4 oxygen Anaerobes: only able to grow in the Ionic strength and osmotic Fermentation: uses either absence of free oxygen pressure lactic-acid, acetic-acid, carbon Microaerophiles: requires oxygen at lower Light dioxide, and/or proteolysis levels than atmospheric levels Photosynthesis: converts light energy into chemical energy Capnophiles: requires CO2 for optimal Temperature (most are (BacT in vet med do NOT do growth mesophilic this!) 2023 Bacteriology 20   Gaseous requirements Obligate aerobes: notice growth on top closest to oxygen Obligate anaerobes: notice growth on bottom farthest from the oxygen Facultative anaerobes: most growing near oxygen but many growing at other distances from oxygen Aerotolerant: oxygen has no effect on growth Ideal temperature (environmental factor) → Majority of pathogenic bacteria grow around 10-48 degrees Celsius 2023 Bacteriology 21 Bacterial Reproduction Reproduction occurs via binary fission Chromosomes duplicate, cell elongates and divides, each contain their own DNA identical to one another Amount of time that is required for a bacterial cell to divide into 2 daughter cells its known as generation time 2023 Bacteriology 22  Bacterial Growth Curve: 4 Phases 1) Lag phase: cells get larger, cell metabolism is active, but no division is occurring 2) Exponential/logarithmic phase: multiplication of cells at maximal rate 3) Maximal stationary phase: Static phase due to balance between slow multiplication and cell death – due to lack of nutrients or accumulation of toxins. Also, this is the phase here a spore would form 4) Decline/death phase: cell death occurring significantly more than cell growth 2023 Bacteriology 23 2023 Bacteriology 24  Methods for Bacterial Counting Microscopic counting: Colony Counting: Direct smear: counting from a fixed & Spread plate method: Fixed volume stained smeared from a defined fluid from ten-fold dilution is spread on volume the surface of the medium. Counting chamber: Use of a calibrated Bacteria grows on the surface slide from a fixed volume of bacterial Pour plate method: Fixed volume suspension. Counting the amount of from ten-fold dilution is placed in bacterial cells in each square. the petri dish and mixed together with the agar. Bacteria grow on the surface and within the agar 2023 Bacteriology 25  Phylogeny and Taxonomy Bacterial phylogenetic Bacterial taxonomy is the study of bacterial identification, nomenclature, and classification. This allows for permitting accurate classifications are information, precise naming, and the ability to group similar based on their 16s organisms rRNA genes – which Polyphasic taxonomy is the classification of bacteria based on their are highly conserved genotypic, phylogenetic, and phenotypic properties such as: throughout evolution Morphology and motility DNA profiling Metabolism and physiology 16s rRNA gene sequencing Biochemical characteristics Whole genome sequencing Classifying a bacterial species is different and based on multiple types of similarities: Defined by - ICBN, LPSN, and international journal of systematic and evolutionary microbiology 2023 Bacteriology 26  We Live in a Microbial World Beneficial bacteria (and non-harmful) are much more present than harmful bacteria Symbiont = an organism living in symbiosis with Beneficial: another dissimilar organism Symbionts – commensals, mutualism Mutualism = when two organisms from different Free-living (planktonic) species are in a symbiotic relationship where they Harmful: both are benefited. These are your pathogenic bacteria: Commensalism = the relationship between two Obligate pathogens species where one is consuming food or has some Facultative pathogens other benefit and neither are being harmed or Opportunistic pathogens benefited Accidental pathogens 2023 Bacteriology 27  Pathogens: An infectious agent (microorganism) that can cause disease upon colonization of the host Obligate pathogen: a microorganism which must infect its host and cause disease in order for them to be able to multiply and transmit form one host to another Facultative pathogen: a microorganism which can infect and multiply in hosts but is almost able to multiply within the environment Opportunistic pathogen: a microorganism that normally does not cause disease but if within a certain condition they can become pathogenetic (E.g. suppressed host immune system) 2023 Bacteriology 28  Bacterial Pathogenesis Host Pathogen Environment Breed age, sex, (Geno)type Housing, genotype management, hygiene Physiology and Virulence, Nutrient ‘damage’ resistance, survival Immunity Route, vector Disease control tropism -- Inoculation dose -- 2023 Bacteriology 29  An Infection does not Always Result in Disease Disease: a disorder of structure or function in the host that adversely impacts the host and is not simply a direct result of physical injury Infectious disease: a disease caused by pathogens and is transmitted to other hosts Pathogenesis: biological mechanism(s) that lead to a disease → how it causes the disease. Pathogenicity: the ability of a microorganism to cause damage to the host Infection: the invasion and multiplication of pathogens in either an individual or a population Virulence: the relative capacity of a pathogen to damage a host → the severity of disease (varies amongst pathogens) 2023 Bacteriology 30  Bacterial Pathogenesis For something to act as a pathogen they must be able to find an appropriate host → compete with microbiota and adhere to host tissues → evade or overcome the hosts defense mechanisms → and be able to express their genes that cause a disease. Basically, either the BacT is phagocytosed, but if infection is not cleared by immune system, then inflammation is activated. 2023 Bacteriology 31 Bacterial Pathogenesis: Inflammation The biological response of host tissue to a harmful stimuli such as pathogens and/or their metabolites and can be caused by: Local tissue damage – from toxins and/or immune response Toxaemia – causing structural or functional alteration of host cells Acute systemic disease Chronic disease 2023 Bacteriology 32  Iceberg Concept of Disease Majority of bacteria that cause infection are asymptomatic (subclinical disease) – but still may have the ability to infect others Other bacteria may cause mild illness, while a smaller group can cause severe disease and death Exposure doesn’t always mean infection 2023 Bacteriology 33  The 5 consequences of host- pathogen interaction 1) No colonization (exposure without infection) 2) Infection → subclinical disease 3) Infection → disease → recovery 4) Infection → disease → persistence (carrier of the disease) 5) Infection → disease → death or disability 2023 Bacteriology 34  Time Periods, Symptoms, and Infectiousness of Pathogens Latent period: When the pathogen is multiplying and colonizing but the host is not infectious yet Infectious period: Current host is now able to transmit the pathogen to another host Incubation period: time when the pathogen is growing and multiplying within the host before the onset of clinical signs or disease 2023 Bacteriology 35  Bacterial Virulence Factors Virulence factors = bacterial traits that allow for pathogenicity Allows the bacteria to colonize in the host either extracellularly or intracellularly Majority pathogenic bacteria are extracellular An obligate intracellular pathogen needs to be inside the host cell to replicate Facultative intracellular pathogens can reproduce inside a host cell if the opportunity arised 2023 Bacteriology 36  Some Types of Virulence Factors of Bacteria… Capsule, flagella, and fimbria being present on the bacterial cell Toxins (endotoxins and exotoxins) Biofilm formation Quorum sensing Capability of being intracellular Ex. Listeria = intracellular 2023 Bacteriology 37  Exotoxin VS. Endotoxin Exotoxin Endotoxin Produced by live bacteria -- both G+ and G- Physical component of the cell wall within G- bacteria, cell death is how toxin is released. Can be They are proteins G+ too (newly discovered) They are a lipopolysaccharide (LPS) with lipid A (the Susceptible to be damaged by heat (heat liable) virulent portion) Not easily damaged by heat (heat stable) They are potent toxins that have very specific activity in the host. (e.g, a given exotoxin could be a They are moderate toxins, with unspecific activity neurotoxin, leukotoxin, enterotoxin, etc) Highly antigenic – bigger immune response Weakly antigenic – smaller immune response Synthesis is determined outside of chromosomal Coded for within their chromosomal DNA DNA (likely within the plasmid genes) 2023 Bacteriology 38  Is it easier to make a vaccine against an endotoxin or exotoxin? Bonus Why? 2023 Bacteriology 39  Is it easier to make a vaccine against an endotoxin or exotoxin? Exotoxin b/c protein antigen Lipid antigens are hard to make vaccines for 2023 Bacteriology 40  Exotoxins are a Superantigen Cause dysfunction of the host immune system by finding a “loophole” around the adaptive immune system in which they will link the two most important antigen receptors This linkage will result in a huge T-cell proliferation and cytokine release with no immune protection in the host body. (the receptors are still activated but there's no antibodies or other specific antigenic effects to go after the bacteria) This causes: Fever Shock Multiple-organ system failure “ Toxic Shock Syndrome” 2023 Bacteriology 41  Quorum sensing Quorum sensing = is the regulation of gene expression in response to fluctuations in cell- population density. Quorum Summery: sensing bacteria produce and Bacteria: release chemical signal Depending on density molecules called autoinducers “communicate” via autoinducers or that increase in concentration as pheromones a function of cell density. The For the ultimate purpose of detection of a minimal threshold altering/regulating gene expressing stimulatory concentration of an autoinducer leads to an alteration Importance: AMR in gene expression 2023 Bacteriology 42  What is the best explanation of quorum sensing? A. is the regulation of gene expression in response to fluctuations in cell-population density to make toxins B. is communication for the purpose of making biofilm C. is bacteria produce and release autoinducers that increase in concentration as a function of cell density which in turn regulate gene expression 2023 Bacteriology 43  What is the best explanation of quorum sensing? A. is the regulation of gene expression in response to fluctuations in cell-population density to make toxins B. is communication for the purpose of making biofilm C. is bacteria produce and release autoinducers that increase in concentration as a function of cell density which in turn regulate gene expression 2023 Bacteriology 44  Biofilm Formation Biofilms are formed from bacteria adhering either to each other or a surface of some kinds and enclosing themselves in a thick, durable, bipolymer matrix which will be hydrated and give them nutrients to survive. Plays a role in persistence infections and plaque formation First Step: attachment! 2023 Bacteriology 45  Quorum Sensing Bacteria will produce signaling molecules to communicate with each other. Once a certain density of a bacteria's population is reached, these signaling molecules will bind to nearby bacterial receptors which will cause the bacteria to express genes to act as a community rather than individually This is how a biofilm formation, sporulation, antibiotic production, etc occurs 2023 Bacteriology 46  Transfer of Virulence Factors Between Bacteria Many genes for virulence factors (bacterial resistance, toxins, etc) are carried by plasmids and bacteriophages and they can be transferred from one bacterial cell to another. This process can be mediated by capsules, fimbria, and bacteriophages Recall that a plasmid is a small circular DNA present in the bacteria. A bacteriophage is a virus that infects and replicates within bacteria 2023 Bacteriology 47  Methods of Bacterial Transfer Bacterial transformation = uptake of naked DNA segment directly, and recipient incorporates the exogenous genetic material Bacterial transduction = a bacteriophage infected cell releases the phage where it then goes to infect another bacterial cell → viral vector Bacterial conjugation = when capsules of two bacteria make direct contact temporarily to transfer the genetic material from donor to recipient 2023 Bacteriology 48  Antimicrobial Resistance Innate resistance: preexisting genomic property (in their genes) Acquired resistance: acquired by mutation or horizonal gene transfer As a clinician used the best possible antibiotic most specific and safe, and only when you know that bacteria is there. 2023 Bacteriology 49  Question Time 2023 Bacteriology 50  A patient comes in showing signs of multiple- organ system failure, shock, and fever. Which type of virulence factor likely caused this? A) Capsule B) Endotoxin C) Exotoxin D) Biofilm formation 2023 Bacteriology 51  A patient comes in showing signs of multiple- organ system failure, shock, and fever. Which type of virulence factor likely caused this? A) Capsule B) Endotoxin C) Exotoxin D) Biofilm formation 2023 Bacteriology 52  T/F: a bacteria releases autoinducers in an environment with every little other bacteria of its kind, this will cause group functioning 2023 Bacteriology 53  T/F: a bacteria releases autoinducers in an environment with every little other bacteria of its kind, this will cause group functioning False, this is quorum sensing, the denser the bacterial population in the given area, the easier it will reach its threshold of autoinducers binding to the receptors of other bacteria → allowing the bacteria to function as a group rather than as an individual 2023 Bacteriology 54  Virulent gene factors transfer to other bacteria via a viral vector, which mechanism is this? A) Bacterial conjugation B) Bacterial transformation C) Bacterial transduction 2023 Bacteriology 55  T/F: all bacterial cell walls contain peptidoglycan 2023 Bacteriology 56  T/F: all bacterial cell walls contain peptidoglycan TRUE! 2023 Bacteriology 57  Which of the following has a thick peptidoglycan layer with (lipo)teichoic acids A) Gram-positive B) Gram-negative C) Mycoplasma D) Mycobacteria 2023 Bacteriology 58  Which of the following has a thick peptidoglycan layer with (lipo)teichoic acids A) Gram-positive B) Gram-negative C) Mycoplasma D) Mycobacteria 2023 Bacteriology 59  Which is correct regarding Gram- negative bacteria A) One plasma membrane B) No cell wall C) Have mycolic acids D) Double plasma membrane with LPS 2023 Bacteriology 60  Which is correct regarding Gram- negative bacteria A) One plasma membrane B) No cell wall C) Have mycolic acids D) Double plasma membrane with LPS 2023 Bacteriology 61  T/F: the nucleoid contains genetic material for virulence 2023 Bacteriology 62  T/F: the nucleoid contains genetic material for virulence FALSE, this is the plasmid 2023 Bacteriology 63  Which bacterial cell structure helps evade phagocytosis A) Flagella B) Fimbriae C) Capsule D) Endospore 2023 Bacteriology 64  Which bacterial cell structure helps evade phagocytosis A) Flagella B) Fimbriae C) Capsule D) Endospore 2023 Bacteriology 65  Which uses Zeihl-Neelsen (acid- base) staining A) Gram-positive B) Gram-negative C) Mycobacteria D) Mycoplasma 2023 Bacteriology 66  Which uses Zeihl-Neelsen (acid- base) staining A) Gram-positive B) Gram-negative C) Mycobacteria D) Mycoplasma 2023 Bacteriology 67  Which of the following is the phase when there a is a balance between death of cells and slow multiplication of cells? A) Lag phase B) Logarithmic phase C) Maximal stationary phase D) Decline phase 2023 Bacteriology 68  Which of the following phase is when there a is a balance between slow multiplication and cell death? A) Lag phase B) Logarithmic phase C) Maximal stationary phase D) Decline phase 2023 Bacteriology 69  You’re counting bacteria and you’re doing this by looking at how many visible masses are seen on top and within a medium. Which method is this? A) Direct smear B) Counting chamber C) Spread plate method D) Pour plate method 2023 Bacteriology 70  You’re counting bacteria and you’re doing this by looking at how many visible masses are seen on top and within a medium. Which method is this? A) Direct smear B) Counting chamber C) Spread plate method D) Pour plate method 2023 Bacteriology 71  Which is not a way to classify bacteria in polyphasic taxonomy? A) Morphology and motility B) Biochemical characteristics C) 16s rRNA gene sequencing D) Virulency 2023 Bacteriology 72  Which is not a way to classify bacteria in polyphasic taxonomy? A) Morphology and motility B) Biochemical characteristics C) 16s rRNA gene sequencing D) Virulency 2023 Bacteriology 73  If a microorganism is only able to multiply and transmit is by infecting and causing disease in a host, which type of pathogen is this? A) Obligate pathogen B) Facultative pathogen C) Opportunistic pathogen 2023 Bacteriology 74  If a microorganism is only able to multiply and transmit is by infecting and causing disease in a host, which type of pathogen is this? A) Obligate pathogen B) Facultative pathogen C) Opportunistic pathogen 2023 Bacteriology 75  Virulence, resistance, and survival are aspects to which parts of the infectious disease complex? A) Host B) Pathogen C) Environment 2023 Bacteriology 76  Virulence, resistance, and survival are aspects to which parts of the infectious disease complex? A) Host B) Pathogen C) Environment 2023 Bacteriology 77  T/F: an infection always causes disease 2023 Bacteriology 78  T/F: an infection always causes disease FALSE!!!!! 2023 Bacteriology 79  T/F: within infection, the step after entering a host is to trigger an inflammatory response 2023 Bacteriology 80  T/F: within infection, the step after entering a host is to trigger an inflammatory response FALSE, its adherence to host tissues 2023 Bacteriology 81  T/F: an infection will always lead to a carrier of the disease 2023 Bacteriology 82  T/F: an infection will always lead to a carrier of the disease FALSE, First: an infection doesn’t always lead to disease, which would need to occur in order to be a carrier Secondly: even if a host has disease, it doesn’t mean that microorganism has the capacity to leave the host as a carrier 2023 Bacteriology 83  Which phase is when the bacteria is multiplying but not yet contagious? A) Latent B) Incubation C) Infectious 2023 Bacteriology 84  Which phase is when the bacteria is multiplying but not yet contagious? A) Latent B) Incubation C) Infectious 2023 Bacteriology 85  The onset of symptoms occurs at the end of which phase? A) Latent period B) Infectious period C) Incubation period 2023 Bacteriology 86  The onset of symptoms occurs at the end of which phase? A) Latent period B) Infectious period C) Incubation period 2023 Bacteriology 87  A patient comes in showing signs of multiple- organ system failure, shock, and fever. Which type of virulence factor likely caused this? A) Capsule B) Endotoxin C) Exotoxin D) Biofilm formation 2023 Bacteriology 88  A patient comes in showing signs of multiple- organ system failure, shock, and fever. Which type of virulence factor likely caused this? A) Capsule B) Endotoxin C) Exotoxin D) Biofilm formation 2023 Bacteriology 89  T/F: a bacteria releases autoinducers in an environment with every little other bacteria of its kind, this will cause group functioning 2023 Bacteriology 90  T/F: a bacteria releases autoinducers in an environment with every little other bacteria of its kind, this will cause group functioning False, this is quorum sensing, the denser the bacterial population in the given area, the easier it will reach its threshold of autoinducers binding to the receptors of other bacteria → allowing the bacteria to function as a group rather than as an individual 2023 Bacteriology 91  Virulent gene factors transfer to other bacteria via a viral vector, which mechanism is this? A) Bacterial conjugation B) Bacterial transformation C) Bacterial transduction 2023 Bacteriology 92  Virulent gene factors transfer to other bacteria via a viral vector, which mechanism is this? A) Bacterial conjugation B) Bacterial transformation C) Bacterial transduction 2023 Bacteriology 93  Bacteria make direct contact temporarily to transfer the genetic material from donor to recipient is? A) Bacterial conjugation B) Bacterial transformation C) Bacterial transduction 2023 Bacteriology 94  Bacteria make direct contact temporarily to transfer the genetic material from donor to recipient is? A) Bacterial conjugation B) Bacterial transformation C) Bacterial transduction 2023 Bacteriology 95  Which is NOT a virulence factor? A. Capsule B. Intracellular bacteria C. Flagella D. Pilin E. Mesophilic 2023 Bacteriology 96  Which is NOT a virulence factor? A. Capsule B. Intracellular bacteria C. Flagella D. Pilin E. Mesophilic 2023 Bacteriology 97  A dog come into your clinic with signs of the flu. After diagnostics you suspect lepto because this organism is seen on a urinalysis. What virulence factor does this visually spirochete express? A. Plasmid with virulence genes B. Flagella C. Endoflagella D. Intracellular Bacteria 2023 Bacteriology 98  A dog come into your clinic with signs of the flu. After diagnostics you suspect lepto because this organism is seen on a urinalysis. What virulence factor does this visually spirochete express? A. Plasmid with virulence genes B. Flagella C. Endoflagella D. Intracellular Bacteria 2023 Bacteriology 99  A noobie forgets the alcohol step in gram stanning. How would this effect your gram stanning A. You would only see mycoplasma B. All Bacteria would be pink C. All Bacteria would be Purple D. All Bacteria would be clear E. No change. Alcohol is bad anyways. 2023 Bacteriology 100  A noobie forgets the alcohol step in gram stanning. How would this effect your gram stanning A. You would only see mycoplasma B. All Bacteria would be pink C. All Bacteria would be Purple D. All Bacteria would be clear E. No change. Alcohol is bad anyways. 2023 Bacteriology 101  Which type of bacteria actually do contain sterols but no cell wall? A. Gram + B. Gram – C. Mycobacteria D. Mycoplasma E. Intracellular Bacteria 2023 Bacteriology 102  Which type of bacteria actually do contain sterols but no cell wall? A. Gram + B. Gram – C. Mycobacteria D. Mycoplasma (damages cilia = pneumonia in pigs) E. Intracellular Bacteria 2023 Bacteriology 103  What is the first step in the formation of biofilm? A. Enclosing themselves in a thick, durable, bipolymer matrix B. Making a capsule C. Attachment to a surface D. Spore formation E. Superantigen creating cytokine storm 2023 Bacteriology 104  What is the first step in the formation of biofilm? A. Enclosing themselves in a thick, durable, bipolymer matrix B. Making a capsule C. Attachment to a surface D. Spore formation E. Superantigen creating cytokine storm 2023 Bacteriology 105  Superantigen is a? A. Superhero immune cell killing antigens B. An overstimulated phagocyte C. Endotoxin that evades MHC complexes and creates a cytokine storm D. Exotoxin that evades MHC complexes and creates a cytokine storm 2023 Bacteriology 106  Superantigen is a? A. Superhero immune cell killing antigens B. An overstimulated phagocyte C. Endotoxin that evades MHC complexes and creates a cytokine storm D. Exotoxin that evades MHC complexes and creates a cytokine storm 2023 Bacteriology 107  Have a good week! 2023 Bacteriology 108  See you next week!! 2023 Bacteriology 109