Bacterial Taxonomy

Question 1

Coccus Gram-positive

Answer 1

Staphyl

Strepto

Question 2

Coccus Gram-negative

Answer 2

Neisseria

Question 3

Bacillus Gram-positive

Answer 3

Clostridium
Corynebacterium
Bacillus
Listeria
Mycobacterium 
Gardnerella

Question 4

Bacillus Gram-negative

Answer 4

Enterics: E. coli, Shigella, Salmonella, Yersinia, Kelbsiella, Proteus, Enterobacter, Serratia, Vibrio, CAmpylobacter,
Helicobacter, Pseudomonas, Bacteroides
Respiratory: Haemophilus, Legionella, Bordetella
Zoonotic: Francisella, Brucella, Pasteurella, Bactonella

Question 5

Branching filamentous Gram-positive

Answer 5

Actinomyces

Nocardia

Question 6

Pleomorphic Gram-negative

Answer 6

Rickettsiae
Chlamydiae
-Both use Giemsa

Question 7

Spiral Gram-negative

Answer 7

Spirochetes: Leptospira, Borrelia, Treponema

Question 8

No cell wall

Answer 8

Mycoplasma (contains sterols)

Question 9

Contains mycolic acid and high lipid content

Answer 9

Mycobacteria

Question 10

Obligate aerobes - what are they?
Examples.
What kind of infections?

Answer 10

Uses an O2 dependent system to generate ATP
Nocardia, Pseudomonas aeruginosa (burn wounds, diabetes, nosocomial, cystic fibrosis), Mycobacteria tuberculoss, Bacillus (Nagging Pests Must Breathe) and Reactivation of M. tuberculosis

Question 11

Obligate anaerobes - what are they?
Examples.
Where are they normally seen?
What antibiotics are ineffective?

Answer 11

Lack catalase or superoxide dismutase so susceptible to oxidative damage
Foul smelling, difficult to culture, produce gas (CO2 and H2)
Clostridium, Bacteroides, and Actinomyces (Can’t Breathe Air)
Normal in the GI, pathogenic elsewhere
Can’t use aminO2glycosides

Question 12

Intracellular
Obligate types?
Facultative types?

Answer 12

Obligate: Rickettsia, Chlamydia - can’t make their own ATP (stay inside when Really Cold)
Facultative: Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Legionella, Yersinia pestis (Some Nasty Bugs May Live FacultativeLY)

Question 13

Encapsulated bacteria - importance?
What test is used to detect?
Examples.
How are these cleared?

Answer 13

Capsule is antiphagocytic virulence factor (capsule + protein conjugate serve as antigen in vaccines)
Positive quellung reaction (capsule will swell)
Streptococcus pneumoniae, Haemophilus influenzae type B, Neisseria meningitidis, Escherichia coli, Salmonella, Klebsiella pneumoniae, group B Strep (SHiNE SKiS).
Opsonized - cleared by spleen (Asplenics have decreased opsonizing ability and are at risk for severe infections)

Question 14

Catalase-positive Organisms - how they work?
Who gets these infections?
Examples.

Answer 14

Catalase degrades H2O2 before it can be converted to microbicidal products by the enzyme myeloperoxidase.
People with chronic granulomatous disease (NADPH oxidase deficiency) have recurrent infections because they degrade the limited H2O2.
Pseudomonas, Listeria, Aspergillus, Candida, E. coli, S.aureus, Serratia (PLACESS forsyour cats)

Question 15

Urease-positive bugs

Answer 15

Crytococcus, H. pylori, Proteus, Ureaplasma, Nocardia, Klebsiella, S. epidermidis, S. saprophyticus (CHuck norris hates PUNKSS)

Question 16

Pigment-producing bacteria

Answer 16

Actinomyces isralii - yellow sulfur granules (filaments of bacteria - Israel has yellow sand)
S. aureus - yellow pigment (aureus = gold)
Pseudomonas aeruginosa - blue/green pigment (Aerugula is green)
Serratia marcescens - red pigment (maraschino cherries)

Question 17

Bacterial virulence factors - what are they?

Answer 17

Promote evasion of host immune response

Question 18

Protein A

Answer 18

Binds Fc region of Ig. Prevents opsonization and phagocytosis. Seen in S. aureus

Question 19

IgA protease

Answer 19

Enzyme that cleaves IgA. Secreated by S. pneumoniae, H. influenzae type B, and Neisseria (SHiN) in order to colonize respiratory mucosa

Question 20

M protein

Answer 20

Helps prevent phagocytosis. Expressed by group A. streptococci.

Question 21

Vaccines

Answer 21

Vaccines with polysaccharide capsule antigen - protein is conjugated to the polysaccharide antigen to promote T-cell activation and subsequent class switching. A polysaccharide antigen alone cannot be presented to T cells; therefore only IgM antibodies would be produced.
Pneumovax - polysaccharide wiht no conjugated protien
Prevnar - conjugated vaccine
H. influenzae type B - conjugated vaccine
Meningococcal vaccines - conjugated vaccine

Question 22

Exotoxin Source
Secreted?
Made of?
Location of genes?
Toxicity?
Antigenicity?
Vaccines?
Heat stability?
Diseases

Answer 22

Certain species of some gram-positive and gram-negative bacteria
Yes secreted
Polypeptide 
Plasmid or bacteriophage
High toxicity
Induce high-titer antibodies called antitoxin
Toxoids used as vaccines
Destroyed rapidly at 60 degrees C
Tetanus, botulism, diphtheria

Question 23

Endotoxin Source
Secreted?
Made of?
Location of genes?
Toxicity?
Clinical effects?
Mode of action?
Antigenicity?
Vaccines?
Heat stability?
Diseases

Answer 23

Outer cell membrane of most gram-negative bacteria
Not secreted
Lipopolysaccharide
Bacterial chromosome
Low toxicity 
Fever, shock clinically
Induces TNF and IL-1
Poorly antigenic
No toxoids formed so no vaccines
Stable at 100 degree C
Meningococcemia; sepsis by Gram-neg rods