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Flashcards in Micro Deck (83)
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1
Q

what mycobacteria are considered rapid growers?

A

M. fortuitum
M. chelonae
M. abcessus

2
Q

What is a photochromogen?

A

Turns yellow on plate when grown in light

3
Q

What mycobacteria are photochromogens?

A

M. kansasii
M. marinum
M. asiaticum

4
Q

What is a scotochromogen?

A

Turns yellow on plate with growth in light or dark

5
Q

What mycobacteria are scotochromogens?

A

M. gordonae
M. scrofulaceum
M. xenopi

6
Q

which mycobacteria are considered non-chromogens?

A

MAC
M. ulcerans
M. haemophilum
MTB**although classification does not technically apply

7
Q

What serogroups of vibrio cholera cause disease?

A

O1 and O139

8
Q

What type of E. coli produces shiga-like toxin?

A

Enterohemorrhagic E. coli (EHEC)

*most common strain O157:H7

9
Q

What bacteria is most common cause of Guillan-Barre?

A

Campylobacter jejuni

10
Q

3 major caauses of pneumonia in COPD patients?

A

H. flu, moraxella catarrhalis, legionella pneumophilia

11
Q

What are HACEK organisms

A

Causes of culture negative endocarditis

Haemophilus, Aggregetibacter, cardiobacterium, eikenella, Kingella

12
Q

ideal protocol for blood cultures

A

3 sets, drawn at separate times (1-8 hrs apart), each paried with adequate volume (20-30cc)

13
Q

Causes of bacterial meningitis in neonates

A

GBS, gram - bacilli, listeria

14
Q

Causes of bacterial meningitis in kids

A

N. meningitidis, S. pneumo, H. flu type B

15
Q

Causes of bacterial meningitis in adults

A

S. pneumo, N. meningitidis

16
Q

Causes of meningitis in AIDS pts

A

S. pneumo, MTB, cryptococcus neoformans

17
Q

Cause of rate bite fever (fever, rash, b/l ankle + shoulder pain)

A

streptobacillus moniliformis

18
Q

what are the hemadsorption/hemagglutinin tests? What viruses can they detect?

A

hemagglutinins adsorb guinea pig RBCs

influenza and parainfluenza viruses

19
Q

Name the 1 ssDNA non-enveloped viruses

A

Parvovirus

20
Q

2 dsDNA non-enveloped viruses

A

adenovirus
papillomavirus
polyomavirus

21
Q

3 dsDNA enveloped viruses

A

herpes virus
hepadnavirus (HBV)
poxvirus

22
Q

ssRNA non-enveloped viruses

A

Picornaviridae (polio virus, enterovirus, HAV, rhinovirus)
calciviridae (norovirus)
Hepeviridae (HEV)

23
Q

dsRNA non-enveloped virus

A

reoviridae (rotavirus)

24
Q

ssRNA enveloped virus

A
  • Flaviviridae (HCV, yellow fever, WNV, dengue)
  • Togaviridae (rubella, EEE, WEE)
  • Retroviridae (HIV, HTLV)
  • Orthomyxoviridae (influenza)
  • Paramyxoviridae (RSV, parainfluenza, mumps, measles)
  • Rhabdoviridae (Rabies)
  • Coronavridiae
  • Arenaviridae
  • Bunyaviridae (hantavirus, california encephalitis)
  • Delta virus (HDV)
25
Q

HBV is what type of virus?

A

enveloped dsDNA

26
Q

HCV is what type of virus?

A

enveloped ssRNA

27
Q

What subtypes of adenovirus are associated with hemorrhagic cystitis?

A

11 and 12

28
Q

What subtypes of adenovirus are associated with childhood gastroenteritis?

A

40 and 41

29
Q

What is antigenic drift and which virus shows this?

A

Antigenic drift=minor changes, due to point mutations in H&N genes
influenza A

30
Q

What is antigenic shift and which virus shows this?

A

Antigenic shift=major changes, due to genetic reassortment between strains (causes worldwide pandemics)
Influenza A

31
Q

What is name of measles virus?

A

morbillivirus

32
Q

most common cause of viral meningitis

A

enterovirus

33
Q

viral cause of myocarditis

A

coxsackie B

34
Q

cause of hand, foot and mouth disease

A

coxsackie A

35
Q

What is vector for dengue and yellow fever

A

Aedes mosquito

36
Q

What is vector for WNV

A

culex mosquito

37
Q

What is mechanism of MRSA?

A

mecA gene; encodes PBP2A; detected by latex agglutination tests

38
Q

Which two types of malaria can remain dormant in liver?

A

P. vivax and P. ovale.

39
Q

What parasites are cultured on a bed of e. coli?

A

Acanthamoeba and Naegleria

40
Q

What does sandfly transmit?

A

Leismania

sandfly aka phlebotomus and lutzomyia

41
Q

What stain detects microsporidia in stool sample?

A

modified trichrome

42
Q

which type of malaria causes nephrotic syndrome?

A

P. malariae

43
Q

which type of malaria shows CNS involvment?

A

P. falciparum

44
Q

which type of malaria shows hemosidinuria, hemoglobinuria, and renal failure?

A

P. falciparum (“blackwater fever”)

45
Q

which type of malaria infect young red cells?

A

P. vivax and P. ovale

46
Q

which type of malaria infect old red cells?

A

P. malariae

47
Q

which types of malaria show schuffner dots (stippling)?

A

P. vivax and P. ovale

48
Q

What nematode can cause iron deficiency anemia

A

hookworms-ancylostoma duodenale and necator americanus

49
Q

What causes visceral larva migrans

A

toxocara canis (dog tapeworm) and cati (cat roundworm)

50
Q

Which trematode (fluke) is a risk factor for cholangiocarcinoma?

A

Clonorchis sinesis/opisthorchis

51
Q

What cestode (tapeworm) is associated with vit B12 def?

A

Diphyllobothrium latum (fish tapeworm)

52
Q

Which type of fungus requires fungal medium overlaid with olive oil?

A

Malassezia furfur

*requires lipid supplementation for growth

53
Q

Bird seed (niger seed) agar is used to identify which fungus

A

cryptococcus neoformans (demosntrates phenol oxidase activity)

54
Q

Which species of aspergillus is resistant to amphotericin B

A

A. terreus

55
Q

Positive germ tube test ID’s which yeast?

A

Candida albicans

56
Q

Rapid trelahose assimilation ID’s which yeast?

A

C. glabrata

57
Q

Urease test ID’s which yeast?

A

cryptococcus

58
Q

Phenol oxidase test ID’s which yeast

A

cryptococcus neoformans

59
Q

Which candida species shows “feet” around colonies

A

C. albicans

60
Q

What 2 bacteria are PYR pos?

A

Group A strep (strep pyogenes) and enterococcus

61
Q

What is buffered charcoal yeast extract (BCYE) used to grow?

A

legionella

62
Q

What is thiosulfate-citrate-bile salt-sucrose (TCBS) agar used to grow

A

Vibrio spp.

63
Q

which vibrio spp is sucrose fermenting?

A

Vibrio cholera

64
Q

At what temperature does yersinia enterocolitica grow best?

A

25-30 deg

65
Q

At what temp does campylobacter grow best

A

42

66
Q

Which staph spp is novobiocin resistant/

A

S. saprophyticus

67
Q

Which strep spp is susceptible to optochin (P disk)?

A

S. pneumo

68
Q

Name 2 bacteria which produce CAMP factor

A

Group B strep (strep agalacticae) and Listeria monocytogenes

69
Q

Name 2 bacteria which produce positive PYR test

A

Group A strep (strep pyogenes) and enterococcus

70
Q

Which gram neg bacteria are oxidase pos

A

Neisseria, moraxella, pseudomonas, legionella, curved gram neg rods (campylobacter, vibrio, helicobacter)

71
Q

Which gram neg bacteria are oxidase neg

A

enterobacteriaceae

72
Q

which bacteria is positive for indole

A

E. coli

73
Q

Which 2 bacteria are rapid urease pos?

A

H. pylori and proteus

74
Q

Which bacteria are positive for hippurate hydrolysis

A
C. jejuni
Listeria monocytogenes
Strep. agalacticae
Gardnerella vaginalis
Legionella pneumophila
75
Q

which staph spp is positive by slide coagulase test but negative by tube coagulase

A

S. lugdunensis

76
Q

How can you tell apart group A vs group B strep

A

Both are beta hemolytic and catalase neg

  • Group A strep: PYR+ and bacitracin (A disk) susceptible
  • Group B strep: PYR-, Bacitracin (A Disk) resistant
77
Q

What type of hemolysis does S. pneumo show

A

alpha

78
Q

What type of hemolysis does enterococcus show

A

none! gamma-hemolytic

79
Q

How can you differentiate Bacillus anthracis from bacillus cereus

A

B. anthracis: non-hemolytic and non-motile

B. cereus: beta hemolytic and motile

80
Q

Which rapidly growing mycobacteria is NaCL tolerant

A

M. abcessus

81
Q

Which rapidly growing mycobacteria uses citrate

A

M. chelonae

82
Q

Which rapidly growing mycobacteria uptakes iron, is NaCL tolerant and uses nitrate

A

M. fortuitum

83
Q

What causes roseola

A

HHV-6

aka sixth disease