Bacteriology - Part I (Classification)

Question 1

Gram Positive cell wall structure

Answer 1

Consists of cytoplasmic membrane (including phospholipids and protein) and peptidoglycan which contains lipotechoic acid

Question 2

Gram negative cell wall structure

Answer 2

Consists of inner membrane (including phospholipids and protein), periplasm (Peptidoglycan), and outer membrane (porin, lipid A endotoxin and lipopolysaccharides)

Question 3

Lipopolysaccharide components

Answer 3

O-antigen repeat (variable strain to strain), outer core and inner core

Question 4

Capsule functions

Answer 4

made mostly of polysaccharides, facilitates interactions between bacteria and can go undetected by host’s immune system, and protects against different forms of clearance

Question 5

Flagella functions

Answer 5

promotes mobility toward or away from chemicals or cell attachment, recognized by the immune system but doesn’t always have to be expressed, can be polar or at both ends of cell

Question 6

Pili (fimbriae)

Answer 6

adhesion molecules that assist with colonization and is implicated in virulence

Question 7

Spore formation

Answer 7

when unfavorable conditions exist some low G/C + bacillus form these and they are not easily killed

Question 8

What bacterial genus lacks a cell wall?

Answer 8

Mycoplasma

Question 9

Host damage - weak response

Answer 9

Weak responses allow the pathogen to damage the host

Question 10

Host damage - strong response

Answer 10

strong responses are excessive and can damage the host themselves

Question 11

Types of bacterial niches

Answer 11

Obligate aerobe, facultative anaerobe, obligate anaerobe, microaerophile, and aerotolerant anaerobe

Question 12

Obligate aerobe

Answer 12

requires O2 to survive, has catalase, superoxide dismutase,

Question 13

Example of Obligate aerobe

Answer 13

Mycobacterium Tuberculosis

Question 14

Facultative anaerobe

Answer 14

more growth in the presence of oxygen but can grow in anaerobic areas too, has catalase and superoxide dismutase

Question 15

Example of Facultative anaerobe

Answer 15

Enterobacteriae

S. Aureus

Question 16

Obligate Anaerobe

Answer 16

Dies in the presence of oxygen, no enzymes available to neutralize toxic by-products

Question 17

Example of obligate anaerobe

Answer 17

Costridium

Question 18

Microaerophile

Answer 18

low oxygen concentration required for growth and has superoxide dismutase

Question 19

Example of Microaerophile

Answer 19

Neisseria gonorrhoeae

Question 20

Aerotolerant anaerobe

Answer 20

Oxygen can be present but just doesn’t use it, has superoxide dismutase

Question 21

Example of Aerotolerant anaerobe

Answer 21

Lactobacillus