Microbiology

Question 1

What is the major component in LPS of g- bacteria which makes the patient sick?

Answer 1

Lipid A

Question 2

Which organism has yellow orange appearance, named “sulfur granule”?

Answer 2

Actinomyces

Question 3

which bacteria are fastidious?
(not grow on std media)

Answer 3

H. influenza
legionella

Question 4

how can we differentiate strep?
all are catalase -
all make chain

Answer 4

based on hemolysis on blood agar

beta: BSP(bacitracin sensitive pyogen) #agalactiae

alpha:OSP(optochin sensitive pneumonia) CP( has Capsule, Pneumonia)# viridans

gamma:BOB(bile only bovis)#enterococcus

Question 5

which organisms have beta hemolytic pattern on blood agar?

Answer 5

1)beta hemolytic strep(BSP:pyogen)and (#agalactiae)
2)staph aureus
3)pseudomonas

Question 6

what plates are suitable for growing H. influenza?

Answer 6

1)chocolate agar
2)blood agar “if” S. aureus present

Question 7

which culture plates are suitable for each organism?

Answer 7

H.influenza : chocolate agar
neisseria : Thayer martin (=VPN=VCN=supplementel chocolate plus vanco and polymyxin/colistin)
bordetella pertusis : bordet gengou agar(=potato agar)
c. diphtheria : loeffler’s , tellurite
Tb : lowenstein-jensen
mycoplasma pneumoniae : eaton’s agar
G- bacteria : Macconkey’s agar (bile salts inhibit g+ growth), EMB (eosin y and methylene blue inhibit g+ growth)
Ecoli O157:H7 stains : sorbitol Macconkey’s agar(unlike other ecoli cannot ferment sorbitol so make colorless colonies on medium)
legionella : buffered charcoal yeast extract (BCYE)
fungi : sabouraud’s agar
s bovis and enterococcus : bile esculin agar
enterococcus : NACL media
staph aureus(SA) : mannitol salt agar (MSA)
alkalin media : vibrio

Question 8

blood agar can be differential by HEMOLYSIS PATTERN

beta(BSP)
alpha(OSP)
gamma(BOB)

Answer 8

Macconkey’s agar and EMB agar can be differential by LACTOSE FERMENTATION

lactose fermenters(Ecoli…)
lactos non fermenters(shigella…)

Question 9

bile salts inhibit g+ growth
exception?

Answer 9

can grow on bile esculin agar
gamma hemolytic streps
1)BOB(bile only bovis)
2)#bile and Nacl : enterococcus

Question 10

which media is suitable for growth of Bordetella Pertusis?

Answer 10

Bordet-gengou agar
=Potato agar

Question 11

eaton’s agar is the suitable media for growing of which organism?

Answer 11

Mycoplasma Pneumonia

Question 12

how can we differentiate S. Aureus from other staphs?

Answer 12

1)coagulase +
2) mannitol salt agar (MSA) : SA fermentes mannitol and media turns yellow

Question 13

which G- bacteria contain oxidase?

Answer 13

campylobacter
vibrio
pseudomonas
H. pylori

Question 14

obligate aerobes?

Answer 14

Pseudomonas
TB
Nocardia

Question 15

Obligate anaerobes

Answer 15

Actinomyces
Bacteroids
clostridium

Question 16

درمان عفونت های بی هوازی؟

Answer 16

بالای دیافراگم کلیندامایسین
زیر دیافراگم مترونیدازول
AG NOT effective

Question 17

درمان عفونت های بی هوازی؟

Answer 17

بالای دیافراگم کلیندامایسین
زیر دیافراگم مترونیدازول
AG NOT effective

Question 18

what is pasteur effect?

Answer 18

in facultative anaerobes:oxygen inhibints fermentation

Question 19

obligate intracellular bacteria?
1)Rickettsia
2)chlamydia

Answer 19

Facultative intracellular bacteria?
1)Mb
2)Legionella
3)Salmonella
4)Neisseeia
5)Listeria
6)Brucella
7)Francisella
8)Yersinia Pestis

Question 20

Dairy
Mayonnaise
Eggs
“Potato salad”

Staph aureus

Answer 20

Fried rice
Reheated rice

Bacillus cereus

Question 21

Which receptor on the MQ binds to LPS?

Answer 21

CD14

Question 22

Whst is the mechanism of pen resistance in S.aureus?
Producing beta lactamase

Answer 22

Whst is the mechanism of pen resistance in MRSA?
Changing pen binding proteins(PBPs)

Question 23

what is the treatment of most of the zoonotic bacteria?
bartonella,brucella,Q fever,psittacosis

Answer 23

Doxycyclin

Question 24

FP VDRL/RPR

Answer 24

Infectious mono
Reumatic fever
SLE
Leprosy
Pregnancy