Exam 1: General bacteriology Review Flashcards
T/F. Prokaryotes have no nucleus
T
T/F Bacteria are unicellular microorganisms
T
How do bacteria reproduce?
binary fission
Bacteria have a complex cell wall with a unique component called ______.
Peptidoglycan
What are the 3 groups of bacteria based on their unique cell wall components.
- Gram Positive bacteria
- Gram negative bacteria
- Mycobacteria
What is the unique cell wall component found in gram positive bacteria?
Lipoteichoic acid
What is the unique cell wall component found in gram negative bacteria?
Outer memb. containing lipopolysaccharide (LPS)
What is the unique cell wall component found in Mycobacteria?
Mycolic acid
What component of LPS can activate immune system and exert harmful effects on the host polysaccharide component contributes to antigenicity
Lipid A component
Gram positive stain ____
purple
Gram negative stain ____
pink
Describe why Gram positive bacteria stain purple
large crystal violet and grams iodine complexes cannot escape thick peptidoglycan layer
Describe why Gram negative bacteria stain pink.
picks up safranin because the thin peptidoglycan layer allows the passage of large crystal volet and grams iodine complexes
Acid Fast staining is due to the presence of _____.
mycolic acid
Acid fast positive bacteria have gram ____ cell wall
positive
Acid fast positive organisms stain ____
pink
Describe the staining of Acid fast positive organisms.
Retains the color of carbol fuchsin the primary stain b/c of the presence of mycolic acid in the cell wall
Acid fast negative organisms stain ____
blue
Describe the staining of Acid fast negative organisms.
get decolorized due to the absence of mycolic acid
Structure on the bacterial surface used in locomotion
Flagella
Small thread like structures on bacterial surface facilitate adherence to the host tissue through specific receptors
Pili/ fimbriae
Outer coating of the bacteria made of polysaccharide in most bacteria, help bacteria to evade phagocytosis
Capsule
Survival mech. for some gram pos. bacteria, spores are highly resistant dormant form of bacteria
Endospores
When are endospores produced?
when bacteria are exposed to adverse conditions and when essential nutrients are depleted
What are the 4 bacterial growth pahses?
- Lag phase
- Log phase
- Stationary phase
- Decline phase
What are the 3 types of bacterium that are oxygen dependent:
- aerobic
- microaerophilic
- capnophilic
What are the 2 types of bacterium that are oxygen independent:
- Obligate anaerobe
2. aerotolerant anaerobe
What type of bacterium can be oxygen dependent or independent.
Facultative anaerobe
Proteins produced by bacteria and released to outside and they exert action of specific target cells
Exotoxins
T/F Exotoxins are heat stable
F. Endotoxins are heat stable
T/F Exotoxins are cell wall components
F. Endotoxins
When are endotoxins released?
When bacteria are dead or killed
Bacterial virulence factor produced by pathogenic microbes. indiscriminate binding to MHC class 2 molecule on the antigen presentng cells and T helper cell receptor.
Superantigens
What is the result of superantigens?
Polyclonal T cell activation and massive cytokine release
Microbes come together in masses cling to surfaces, produce extracellular substances and take in nutrients and forms this
Biofilm
Smaller circular DNA present in Bacteria
Plasmids
Virus particles which attach bacteria
Bacteriophages
Virulence factors are transferred between bacteria through processes such as _____, _____, and _____.
Conjugation, Transformation, Transdddution
Science dealing with evolutionary relationship b/t living organisms.
Phylogeny
T/F. Fungi are Eukaryotes
T
T/F. Most bacteria are not pahtogens
t
A microbe that can cause disease
Pathogen
Mech. by which cause disease
pathogenesis
Degree of pahogenicity, includes severity
Virulence
Properties or traits found in isolates that cause disease but which are not found in isolates that cause disease but which are not found in isolates of the same spp. that lack the ability to cause disease
Virulence factors
What predisposes and animal to infectious disease
Predisposition
T/F. The majority of bacteria are intracellular pathogens
F.
What is the sequence of events in bacterial or fungal pahogenesis?
- entry to host
- evade host defence
- colonize the host
- multiply
- exert damage in host
- transmit to other hosts
What are 3 ways bacterium or fungi cause disease?
- depleting the host nutrients by using them
- direct damage to the host cells (toxins)
3 As a result of immune response to the microbe
or combination
Host response to presence of microorganisms or its products
Inflammation
the purpose of being a pathogen or at times adopting a pathogenic lifestyle
Transmission
T/F. Bacterium have no nucleus
T
T/F. Bacterium have a simple cell wall
F. complex
T/F Bacterium have a single linear DNA
F. Circular
T/F Bacterium undergo asexual repro.
T. Binary fission
T/F All bacteria contains peptidoglycan
T
T/F Gram negative bacteria have a thick peptidoglycan layer
F. Gram pos.
T/F Only gram negative bacteria has an outer memb. which contains LPS.
T
T/F. Lipid A or endotoxin is harmful
T
T/F. Only Gram Pos. bacteria contain Teichoic acid on their cell walls
T
T/F Mycobacteria contain mycolic acid and contribute to acid fast positive staining
T