Micro Flashcards
what mycobacteria are considered rapid growers?
M. fortuitum
M. chelonae
M. abcessus
What is a photochromogen?
Turns yellow on plate when grown in light
What mycobacteria are photochromogens?
M. kansasii
M. marinum
M. asiaticum
What is a scotochromogen?
Turns yellow on plate with growth in light or dark
What mycobacteria are scotochromogens?
M. gordonae
M. scrofulaceum
M. xenopi
which mycobacteria are considered non-chromogens?
MAC
M. ulcerans
M. haemophilum
MTB**although classification does not technically apply
What serogroups of vibrio cholera cause disease?
O1 and O139
What type of E. coli produces shiga-like toxin?
Enterohemorrhagic E. coli (EHEC)
*most common strain O157:H7
What bacteria is most common cause of Guillan-Barre?
Campylobacter jejuni
3 major caauses of pneumonia in COPD patients?
H. flu, moraxella catarrhalis, legionella pneumophilia
What are HACEK organisms
Causes of culture negative endocarditis
Haemophilus, Aggregetibacter, cardiobacterium, eikenella, Kingella
ideal protocol for blood cultures
3 sets, drawn at separate times (1-8 hrs apart), each paried with adequate volume (20-30cc)
Causes of bacterial meningitis in neonates
GBS, gram - bacilli, listeria
Causes of bacterial meningitis in kids
N. meningitidis, S. pneumo, H. flu type B
Causes of bacterial meningitis in adults
S. pneumo, N. meningitidis
Causes of meningitis in AIDS pts
S. pneumo, MTB, cryptococcus neoformans
Cause of rate bite fever (fever, rash, b/l ankle + shoulder pain)
streptobacillus moniliformis
what are the hemadsorption/hemagglutinin tests? What viruses can they detect?
hemagglutinins adsorb guinea pig RBCs
influenza and parainfluenza viruses
Name the 1 ssDNA non-enveloped viruses
Parvovirus
2 dsDNA non-enveloped viruses
adenovirus
papillomavirus
polyomavirus
3 dsDNA enveloped viruses
herpes virus
hepadnavirus (HBV)
poxvirus
ssRNA non-enveloped viruses
Picornaviridae (polio virus, enterovirus, HAV, rhinovirus)
calciviridae (norovirus)
Hepeviridae (HEV)
dsRNA non-enveloped virus
reoviridae (rotavirus)
ssRNA enveloped virus
- 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)
HBV is what type of virus?
enveloped dsDNA
HCV is what type of virus?
enveloped ssRNA
What subtypes of adenovirus are associated with hemorrhagic cystitis?
11 and 12
What subtypes of adenovirus are associated with childhood gastroenteritis?
40 and 41
What is antigenic drift and which virus shows this?
Antigenic drift=minor changes, due to point mutations in H&N genes
influenza A
What is antigenic shift and which virus shows this?
Antigenic shift=major changes, due to genetic reassortment between strains (causes worldwide pandemics)
Influenza A
What is name of measles virus?
morbillivirus
most common cause of viral meningitis
enterovirus
viral cause of myocarditis
coxsackie B
cause of hand, foot and mouth disease
coxsackie A
What is vector for dengue and yellow fever
Aedes mosquito
What is vector for WNV
culex mosquito
What is mechanism of MRSA?
mecA gene; encodes PBP2A; detected by latex agglutination tests
Which two types of malaria can remain dormant in liver?
P. vivax and P. ovale.
What parasites are cultured on a bed of e. coli?
Acanthamoeba and Naegleria
What does sandfly transmit?
Leismania
sandfly aka phlebotomus and lutzomyia
What stain detects microsporidia in stool sample?
modified trichrome
which type of malaria causes nephrotic syndrome?
P. malariae
which type of malaria shows CNS involvment?
P. falciparum
which type of malaria shows hemosidinuria, hemoglobinuria, and renal failure?
P. falciparum (“blackwater fever”)
which type of malaria infect young red cells?
P. vivax and P. ovale
which type of malaria infect old red cells?
P. malariae
which types of malaria show schuffner dots (stippling)?
P. vivax and P. ovale
What nematode can cause iron deficiency anemia
hookworms-ancylostoma duodenale and necator americanus
What causes visceral larva migrans
toxocara canis (dog tapeworm) and cati (cat roundworm)
Which trematode (fluke) is a risk factor for cholangiocarcinoma?
Clonorchis sinesis/opisthorchis
What cestode (tapeworm) is associated with vit B12 def?
Diphyllobothrium latum (fish tapeworm)
Which type of fungus requires fungal medium overlaid with olive oil?
Malassezia furfur
*requires lipid supplementation for growth
Bird seed (niger seed) agar is used to identify which fungus
cryptococcus neoformans (demosntrates phenol oxidase activity)
Which species of aspergillus is resistant to amphotericin B
A. terreus
Positive germ tube test ID’s which yeast?
Candida albicans
Rapid trelahose assimilation ID’s which yeast?
C. glabrata
Urease test ID’s which yeast?
cryptococcus
Phenol oxidase test ID’s which yeast
cryptococcus neoformans
Which candida species shows “feet” around colonies
C. albicans
What 2 bacteria are PYR pos?
Group A strep (strep pyogenes) and enterococcus
What is buffered charcoal yeast extract (BCYE) used to grow?
legionella
What is thiosulfate-citrate-bile salt-sucrose (TCBS) agar used to grow
Vibrio spp.
which vibrio spp is sucrose fermenting?
Vibrio cholera
At what temperature does yersinia enterocolitica grow best?
25-30 deg
At what temp does campylobacter grow best
42
Which staph spp is novobiocin resistant/
S. saprophyticus
Which strep spp is susceptible to optochin (P disk)?
S. pneumo
Name 2 bacteria which produce CAMP factor
Group B strep (strep agalacticae) and Listeria monocytogenes
Name 2 bacteria which produce positive PYR test
Group A strep (strep pyogenes) and enterococcus
Which gram neg bacteria are oxidase pos
Neisseria, moraxella, pseudomonas, legionella, curved gram neg rods (campylobacter, vibrio, helicobacter)
Which gram neg bacteria are oxidase neg
enterobacteriaceae
which bacteria is positive for indole
E. coli
Which 2 bacteria are rapid urease pos?
H. pylori and proteus
Which bacteria are positive for hippurate hydrolysis
C. jejuni Listeria monocytogenes Strep. agalacticae Gardnerella vaginalis Legionella pneumophila
which staph spp is positive by slide coagulase test but negative by tube coagulase
S. lugdunensis
How can you tell apart group A vs group B strep
Both are beta hemolytic and catalase neg
- Group A strep: PYR+ and bacitracin (A disk) susceptible
- Group B strep: PYR-, Bacitracin (A Disk) resistant
What type of hemolysis does S. pneumo show
alpha
What type of hemolysis does enterococcus show
none! gamma-hemolytic
How can you differentiate Bacillus anthracis from bacillus cereus
B. anthracis: non-hemolytic and non-motile
B. cereus: beta hemolytic and motile
Which rapidly growing mycobacteria is NaCL tolerant
M. abcessus
Which rapidly growing mycobacteria uses citrate
M. chelonae
Which rapidly growing mycobacteria uptakes iron, is NaCL tolerant and uses nitrate
M. fortuitum
What causes roseola
HHV-6
aka sixth disease