Unusual bacteria and other medically important microorganisms

Question 1

what are the aerobic actinomycetales?

Answer 1

nocardia asteroids
myobacterium tb
myobacterium leprae
myobacterium marinum

Question 2

anaerobic actinomycetales

Answer 2

actinomyces

Question 3

Nocardia asteroids

Answer 3

transmission- inhalation via dust
produces virulent form of pneumonia
symptoms more severe in immunocompromised

Question 4

myobacterium tuberculosis

Answer 4

resevoir- humans
transmission- air droplets from person with disease
phagocytized by alveolar macrophages in lungs but unable to kill due to cell wall
protective granulomas formed due to production of cytokines and upregulation of proteins

Question 5

myobacterium leprae

Answer 5

gentically based obligate intracellular parasite
transmission- coughing, sneezing and prolonged close contact with someone untreated
2 forms- 1. tuberculoid- discrete lesions consisting of well organized granulomas having few bacilli
2. Lepromatous- several nodular or diffuse lesions containing many bacilli in poorly organized granulomas

Question 6

myobacterium marinum

Answer 6

wound infections found in bodies of fresh or saltwater
skin infections relatively uncommon, usually acquired from contact with fish/aquarium
first signs include a reddish or tan skin with a granuloma

Question 7

Actinomyces

Answer 7

70% due to either A. israelii or gerencseriae
live in small spaces btwn teeth and gums causing infection only when they can multiply freely in anoxic enviroment
formation of painful abscesses in mouth, lungs, breast or GI

Question 8

Cell wall of mycobacterium and Nocardia

Answer 8

mycolic acid forms a waxy layer which limits nutrient uptake slowing the growth rate
waxy coat retards normal staining
cord factor- glycolipid on the surface, v toxic due to disruption of oxidative phosphorylation

Question 9

Ziehl Neelsen stain method

Answer 9

1. application of carbolfuchsin- primary stain
2. application of heat- mordant, needed to get into layers
3. application of acid alcohol- decolorizer
4. application of methylene blue- counter stain

Question 10

Mycoplasma ssp

Answer 10

do not have a cell wall
smallest prokaryote
sterols in membrane

Question 11

mycoplasma pneumoniae

Answer 11

causes lung infections
1/3 of infected get “walking pneumoniae” of “tracheobronchitis”
transmission via air droplets from sick pt

Question 12

Mycoplasma genitalium

Answer 12

transmission via having sex with someone infected
women- pain, bleed after sex, discharge
men- urethritis, stinging/burning, discharge

Question 13

ureaplasma

Answer 13

part of the body’s bacterial pop, live in balance

passed during sexual contact

Question 14

Chlamydia

Answer 14

obligate intracellular parasite, depends on host for ATP and NAD
complex life cycle with 2 types: 1. elementary body- infectious form 2. reticulate body- replicative form

Question 15

chlamydia trachomatis

Answer 15

trachoma and sti

Question 16

chlamydia pneumoniae

Answer 16

pneumonia

Question 17

chlamydia psittaci

Answer 17

ornithosis and psittacosis

zoonotic disease

Question 18

Chlamydia life cycle

Answer 18

1. transformation of EB to RB
2. replication of RB
3. transformation of RB to EB
4. lysis

Question 19

Rickettsia

Answer 19

multiply at site of arthropod attachment and produce a lesion
penetrate skin or mucous membranes, multiple in endothelieal cells of small bvs
symp: regional lymphadenopathy, petechial rash, encephalitic signs and gangrene of skin and tissues

Question 20

3 species that cause most Rickettsia human infections

Answer 20

r. rickettsii
r. prowazekii
r. typhi