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365 Cards in this Set
- Front
- Back
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Aerobic
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utilize glucose in presence of oxygen
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Anaerobic
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–will not grow in presence of oxygen, utilize
glucose in absence of oxygen only |
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Facultative
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utilize glucose both O2 and Ana, most
bacteria are facultative (ie enterics, Staph) |
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Microaerophilic
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require increased CO2 & reduced
oxygen to grow |
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Capnophilic
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requires increased CO2 to grow
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Aerotolerant - def and example
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anaerobes that survive temporary
exposure to oxygen (Clostridium tertium) |
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phases of growth: Lag Phase
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slowing down (not good
for biochemical or susceptibility testing usually occurs > 24 hours on agar |
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phases of growth: Exponential or log phase
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good for all testing ( usually at 18-24 hr on agar)
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phases of growth Stationary phase
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for
transporting specimens, |
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what can you add to urine to "stabilize" for transport and subsequent culture
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boric acid or or refrigerate @ one hour, <24 hr
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special growth conditions: anaerobes
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Anaerobes – swab or vial (port o cult)/ absence of O2
if not - organisms will die in one hour! |
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special growth conditions: N. gonorrhea!
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N. gonorrhoea– Jembec plate or charcoal swab, DO
NOT refrigerate (charcoal - protects from harsh environment) - grows on warm mucous membranes |
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what
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Amies charcoal swab - useful for N gonorrhea testing
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what transport media is used for swabs
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Stuart’s or Aimes transport
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what about CSF - how handle for transport
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Room temp (no refridgeration)
Strep pneumo, N. menitigitis |
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tissue
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Usually refrigerate <=12-24 hours for specimens
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components of a gram stain
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Crystal violet – primary stain
Gram’s iodine – mordant Acetone/Alcohol – decolorizer Safranin – counterstain |
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what is a mordant
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substance used to set dyes on fabrics or tissue sections
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problems with gram stain
polys blue polys washed out |
blue- underdecolorized
washed out -over decolorized |
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criteria for bad sputum
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Cells observed on 10X objective (low power)
>= 25 epithelial cells /field Sputum is judged to be spit / not sputum This is not an acceptable specimen for bacterial culture prefer not to use polys as criteria given prevelance of neutropenia |
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what can "rejected" sputum (aka spit) be used for
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AFB , fungus, etc
NOT BACTERIA |
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conclusion about this sputum
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=spit
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what is a methylene blue stain and how used
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stains polys blue, one step, can be useful for stool
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quellung reaction what does it test for
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- test for top two: H. influenza and S. pneumonia
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what is a quellung reaction
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biochemical reaction in which antibodies bind to the bacterial capsule, causes capsular swelling/enlargement
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what
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quellung reaction
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what is Acridine orange stain
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vital stain
for RNA and DNA when Gram stains are negative for bacteria |
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what is a vital stain
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stain that can be applied on living cells without killing them
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what does partially acid fast mean
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capable of retaining the stain carbolfuchsin during mild acid decolorization. This ability is found in bacteria of the genus Nocardia
can use H2SO4, but not HCl as acid |
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what might Fluorescent antibody stains be used to detect
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N. gonorrhoea or Beta Strep group A
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fluorescent stain vs. gram for n. gonorrhea
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for review
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B. Latex agglutination for capsular ag
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really important for CSF - partially treated patient for meningitis
kit with Ab - look for Ag good for n. men., h inf, gr B strp, S. pneumo |
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why use broth
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broth is used to detect low#’s of bacteria that might
not grow on agar media |
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example of selective agar and how to interpret
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Selective – CNA – colistin/naladixic acid agar, blood
based media that selects for G+C and against G-R (colistin and naladixic acid = antibiotics that don't allow G-R to grow |
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example of selective and differential agar
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MacConkey agar –
grows only gram negative rods and differentiates gram negative rods that ferment lactose (pink) from those that do not (colorless) |
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what is being displayed here
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differential nature of MacConkey's agar:
pink - lactose fermentation (e coli) color - lactose nonfermenter (proteus) |
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Gram stain of Staphylococcus
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- Gram positive cocci in clusters
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what
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staph (g+ cocci in clusters)
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what
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Strep, gram + chains (strep pneumo gram stain is invariably on exam)
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what
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micrococcus - gram + in tetrad
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what
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thick gram + rod: Clostridium
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what
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listeria - thin Gr+ rod
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what
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actinomyces, nocardia - branched, gram+ rods
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what
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Neisseria (and moraxella)- gram neg cocci
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what
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acinobacter -variable gram positive/negative staining; variable cocci vs. coccobacilli
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what
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gram negative rods, thin enterobacteriaceae - ex. E coli
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what
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Coccobacilli, gram negative - usually characteristic of Haemophilus spp
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what
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curved, gram negative rod, Vibrio
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what
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gram neg rod, needle shaped - Fusobacterium
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morphologic and chemical fx of Staph group
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Gram + cocci in clusters; catalase +
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fx of staph aureus
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gram positive cocci in clusters; catalase +, coagulase+thermostable DNAase enzyme positive
yellow colony (aureus) can be beta-hemolytic |
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fx of coag negative staph
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gram positive cocci in clusters
coagulase negative usually white colonies usually not beta-hemolytic |
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what is the catalase test
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H2O2 + organism produces bubbles (O2)
recall: staph would all be positive for this test |
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what is coagulase test
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tube free coagulase - organism + rabbit plasma, 35 check at 4 hours (solid clot - positive) if still runny, at 24 hours (solid clot - positive) if runny, negative
slide coag - bound coagulase s. aureus produces both bound and free coagulase |
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what test
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coagulase test - clot formed in positive
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what test
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coagulase, S aureus positive
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what
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catalase test (O2 formation) - all Staph positive
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name virulence factors for S. aureus (5)
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Protein A
capsular polysacharides, enzymes (coagulase), toxins hemolysins |
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what are virulence factors
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"fx" of organism that enable them to navigate around the host (get in, evade immune system, etc)
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name diseases associated with s aureus
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toxic shock syndrome
scalded skin syndrome, soft tissue infection food poisoning, bacteremia and endocarditis |
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cause
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S aureus
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toxic shock syndrome
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s aureus
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s aureus toxins
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Panton valentine leucocidin (PVL),
Exfoliatin (SSS), Enterotoxins (food poisoning), Toxic shock syndrome toxin (TSST-1) |
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what accounts for resistance in MRSA
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Penicillin binding protein (PBP) produced by mec A gene for resistance to oxacillin
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two bacterial types
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S. aureus (hem) and coagulase neg Staph (not hem)
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what can lead to false positive in catalase activity
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blood - has inherent catalase activity - so try not to get blood in sample with catalase test
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what
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mannitol salt agar test
S aureus ferments mannitol and will turn agar yellow; others may grow (e.g. Staph epidermidis) but not ferment mannitol |
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what
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mannitol salt agar - S aureus positive (yellow) as ferments mannitol
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Staph epidermidis –
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major skin normal flora but
major cause of subacute bacterial endocarditis. Pathogenicity from cell adhesion factors forming biofilms on biologics and plastic (IV catheter) |
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Staph saprophyticus –
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urinary tract infections in the child bearing age female, this species adheres in greater #’s to epithelial cells than
other SCNG. Novobiocin resistant by KB disk test to ID |
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** Staph hemolyticus
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– line related sepsis, this is hemolytic on blood agar, do not confuse with
Staph aureus (HEMOLYTIC THOUGH) |
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name three coag neg staph of importance
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Staph epidermitis, Staph saphrolyticus, Staph hemolyticus
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if this is a Novobiocin KB disk test, what organisms
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Staph saprophyticus (Novobiocin KB test resistant)
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name two micrococcus species
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M. luteus and M. lylae
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cf S aureus to M luteus
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-Both yellow on colonies (M luteus is obnoxiously yellow)
results of Bacitracin, microdase and glucose: - M luteus is Bacitracin susceptible by KB disk test, Staph aureus is Bac resistant - Modified oxidase reaction positive- Microdase test + for M. luteus - M luteus does not ferment Glucose vs. Staph ferment Glu |
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does micrococcus cause problems
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part of natural environment, can cause some trouble in immunocompromised host
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what two bugs, bacitracin test
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micrococcus is Bacitracin susceptible
Staph aureus is Bacitracin resistant |
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what test, what bugs
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Microdase (Modified Oxidase) Test
–Detects cytochrome oxidase –Based on oxidase reaction but contains DMSO to release cytochrome oxidase Bugs: S aureus - no color change, no cytochrome oxidase Micrococus: positive, + cytochrome oxidase |
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what test, name example of what results would be for micrococcus vs. staph aureus
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red - negative control or micrococcus
yellow - positive, staph aureus |
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what is Rothia mucilaginosa
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NF of human skin and oral cavity
Pathogen: central lines, endocarditis, bacteremia of immune suppressed |
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what is unique about Rothia in lab
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Colonies are sticky or mucoid, white and
adherent to the agar worth knowing Large gram positive cocci in pairs or clusters |
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tell me about Streptococci...
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Gram positive cocci in chains and or pairs
Catalase enzyme negative characterized by hemolysis on sheep blood agar |
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what does alpha hemolysis look like on sheep blood agar
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greening of agar, partial hemolysis of rbc
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what does beta hemolysis look like on sheep blood agar
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clearing of agar, complete hemolysis of rbc
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what does gamma hemolysis look like on sheep blood agar
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no clearing of agar, no hemolysis
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three bugs that display alpha hemolysis on sheep blood agar
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Viridans Strep
Strep pneumoniae Abiotrophia (nutritionally variant strep) |
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bugs that display beta hemolysis on sheep blood agar
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Beta hemolytic Strep groups A - G (exc. D)
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display gamma hemolysis on sheep blood agar
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Enterococci and Streptococcus Group D
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what kind of hemolysis, what bugs
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alpha hemolytic, that disk happens to be an optochin disk
options for alpha hemolysis would be: strep pneumo, strep viridans, and abiotrophia. Strep pneumo (as shown here) is resistant to optochin |
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example of beta hemolysis, name bugs
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for review
beta hemolytic strep |
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clever trigger for remembering hemolysis
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review
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example of what type of hemolysis, what two bugs
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gamma hemolysis
Enterococci and Streptococcus Group D |
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how do you group strep
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“C” carbohydrate in the cell wall of the bacteria/latex
agglutination - Lancefield grouping system defining A,B,C,F, and G has human Strep |
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what is group A beta hemolytic strep
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Strep pyogenes
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ID strep pyogenes (if not lancefield typing)
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Bacitracin –susceptible, inhibited (zone ng @ disk)
SXT - resistant PYR – positive (pyrrolidonyl arylmidase) |
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what test
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latex agglutination testing - main way to ID strep species these days by looking for C CHO on cell wall of bugs
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what is SXT useful for
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distinguishing between Gr A and Gr B strep
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virulence factors for Strep pyogenes
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M protein – resistance to phagocytosis
Capsule – hyaluronic acid – resists complement dependent killing Streptolysin O and Streptolysin S – cell toxins O is oxygen labile S is oxygen stable Streptococcal pyrogenic exotoxins |
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dz of strep pyogenes
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Pharyngitis
Impetigo Erysipelas Cellulitis Puerperal sepsis Toxic Shock Sequelae: Rheumatic fever and Glomerulonephritis |
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rheumatic fever, what bug
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strep pyogenes
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what besides s aureus can cause toxic shock
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strep pyogenes
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what, who causes
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impetigo, strep pyogenes
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what, what bug
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erysipelas - Group A (strep pyogenes)
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what caused
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group A strep (strep pyogenes)
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what is the main intent of a PYR test
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helps identify Group A and Group D strep: PYR test is positive for both
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what test
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PYR test, pink is positive - positive is Gr A and enterococcus (not bovis) strep
means that contain relevant enzyme for metabolizing PYR reagent (sort of, simplification) develop with cinnaldehyde |
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most important virulence factor (for testing) in S pyogenes
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M protein (resistant to phagocytosis)
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what is group B strep
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Streptococcus agalactiae
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properties of Strep agalactiae
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- Gram positive cocci in short chains
- Camp test positive - Rapid hippurate hydrolysis (4 hr) = positive |
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what bug is tested in pregnancy at 35-37 weeks
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Pregnant women screened at 35 – 37 weeks
using enrichment methods for GBS |
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in whom is Group B strep (strep agalactiae) pathogenic
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newborns (sepsis, pneumonia, meningitis) and elderly (UTIs in elderly)
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what is the camp test
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test to identify Group B strep (strep agalactiae) based on their formation of a substance (CAMP factor) that enlarges the area of hemolysis formed from Staphylococcus aureus
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what test
|
***camp test - identifies group B strep b/c forms arrowhead (by increasing hemolytic range of s aureus - the white streak across)
double arrows if positive, only one arrow if negative (not shown) |
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what is the Rapid hippurate hydrolysis
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ability of organism to hydrolyze hippurate
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what test
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hippurate test on disk: 4 hours
positive - blue, in this case: Strep agalactia (Gr B) negative - clear, in this case: Strep pyogenes (Gr A) |
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really basic properties of enterococcus
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strep so chains, catalase-
gamma hemolytic, |
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two types of enterococcus
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E. faecium, E. faecalis
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more specific features of enterococcus
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Bile esculin positive
6.5% salt positive PYR positive (Gp. A beta Strep also)* |
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way to distinguish between E. faecium and E. faecalis
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E. faecium = arabinose ferm pos
E. faecalis = arabinose neg |
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enterococcus: drug of choice
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Ampicillin/Vancomycin drugs of choice
note: natural resistance of cephalosporins |
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selective media to screen for VRE
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Can use bile esculin agar with vancomycin to screen for VRE
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clinical conditions with enterococcus
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pathogen of opportunity, normal flora in intestine,
cause UTI, bacteremia, abdominal infections |
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purpose of bile esculin agar
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to distinguish between enterococcus and strep
presence of 4% bile (oxgall) and hydrolyzing esculin |
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test, review
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bile esculin
negative -strep positive - enterococcus |
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what test
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bile esculin test: positive in enterococcus (E/E)
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6.5% salt test - who is allowed to grow and describe what the test looks like
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tube based - looking for turbidity (growth despite extra salt)
enterococcus can grow |
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who can ferment arabinose: e faecium or e faecalis
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"sans" arabinase - so e faecalis can't ferment arabinose
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who is Streptococcus Group D not enterococcus
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strep bovis
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differentiate enterococcus from strep D not enterococcus (bovis)
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both bile esculin positive
strep bovis is negative for PYR and negative growth in 6.5% salt (enterococcus is positive for both of these) |
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what is the clinical association for Strep bovis
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if found in blood, wonder about colonic adenoca
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name two of the alpha hemolytic strep
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S. pneumo and s viridans
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know s pneumo**
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gram positive, lancet shaped, capsule
bile solubility optochin sensitive Strep pneumo, Sensitivo, Solubilo |
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what
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strep pneumo, pairs,
|
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what is a virulence factor for strep pneumo
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polysaccharide capsule is virulence factor
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what is the bile solubility test
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Bile will selectively lyse colonies of Streptococcus pneumoniae while other strep are immune to bile's activity - delineates strep pneumo from other strep (in particular the other alpha hemolytic strep viridans)
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what test
|
review, bile solubility test
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what test
|
optochin test for strep pneumo (sensitive) - helps to delineate strep pneumo from strep viridans
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what is the chemical for optochin
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biochemical ethyl hydrocupreine hydrochloride
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how is resistance to strep pneumo
|
Acquired Resistance to Pen by Pen binding proteins
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how prevent strep pneumo
|
pneumovax
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clinical dz of s pneumo
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Pathogen of pneumonia, sepsis & CSF.
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optochin disk has _ on it
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P, 14 mm is the diameter to indicate resistance
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what is the group of organisms encompassed under Strep viridans, where normally found
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S. mutans S. salivarius S. sanguis S. mitis
mouth, oral flora |
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dz of strep viridans
|
sub acute endocarditis in preexisitng
native valve disease |
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what are the findings of Strep viridans for:Bile esculin, bile solubility, Optochin susceptbility
|
Bile esculin negative
Not bile soluble Optochin resistant - <=13 mm |
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what is the angiosis group
|
more virulent that the group of S. viridans strep and include:
S. anginosus S. constellatus S. intermedius deep tissue abscesses, bacteremia, endocarditis,intra abdominal infections… |
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what do Abiotrophia defectiva and Globicatella adiacens fall under
|
nutritionally variant strep; defective vit B6 (require this)
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what does abiotrophia need
|
vit b6
Will grow in a blood culture bottle – but not on the blood agar plate sub – needs Staph aureus streak to grow “satellite” or media supplemented with vit B6 |
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what dz can Abiotrophia defectiva and Globicatella adiacens get
|
endocarditis - way more resistant to abc
|
|
what
|
Abiotrophia defectiva
Globicatella adiacens only way you can get these organisms to grow on blood agar plate is with a streak of S aureus and subsequent satellitosis |
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what is Leuconostoc species
|
in nursing home patients,
vancoymysin resistant (not VRE!) bile esculin- PYR- |
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what is an important fx to remember about N. gonorrhea growth
|
Neisseria gonnorhoeae will not grow on blood
agar |
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what is the agar of choice for N. gonorrhea
|
Thayer Martin selective agar
|
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name two important gram negative cocci
|
Neisseria spp
Moraxella |
|
what
|
n gonorrhea
|
|
what (direct attention to cocci)
|
N. gonorrhea, Small kidney bean shaped - pairs
|
|
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what chemical test is useful for gram negative cocci, Neisseria, moraxella
|
oxidase test (+)
|
|
what
|
oxidase test
|
|
what, what might be positive for oxidase
|
oxidase test, for review
gram negative cocci, neisseria, moraxella |
|
|
CTA sugar fermentations for identification
|
N. gonnorhoeae Gluc + Mal - Lac - Suc -
N. meningitidis Gluc + Mal + Lac - Suc - N. lactamica Gluc + Mal + Lac+ Suc- B. catarrhalis all negative, Dna’ase + |
|
|
where are GC organisms found in active infection
|
intracellular
|
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what would be a danger to using only a Gram stain to diagnosis N. gonorrhea in the female genital tract
|
acinetobacter can look just like N. gonorrhea on gram stain and the acinetobacter is found on in normal female flora
|
|
what
|
acinobacter gram negative coccobacillus bigger, not always in pairs (in comparison to GC)
|
|
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what's the order for memorizing the sugars for fermentation
|
GMLS
gamal's |
|
|
n. gonorrhea sugar fermentation
|
glucose only
|
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n. meningitidis sugar fermentation
|
glucose+ maltose+
|
|
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n. lactimica sugar fermentation
|
Glucose, maltose and lactose
|
|
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B/M catarrhalis sugar fermatation
|
all negative, DNase+
|
|
|
trick on test with sugar fermentation
|
while you've memorized the GMLS order, that may not be how they present it
|
|
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what color is usu positive for sugar fermentation on tests
|
yellow is usually positive, red is negative
|
|
|
main disease for N. meningitidis and hallmark clinical finding
|
meningitis (!) and petechiae
occurs in young/young adult |
|
|
virulence factor of n. meningiditis
|
capsular polysaccharide
|
|
|
what can predispose one to chronic N. meningiditis
|
Complement deficiencies in 7,8,and 9 can predispose
to chronic type disease |
|
|
association with Waterhouse friedrichsen
|
n. meningiditis
|
|
|
how prevent n. meningitidis, most common form these days in US
|
vaccine;
Type C is the current endemic strain in the USA – problem in college Freshmen living in dorms recommend immunization rifampin prophaxylasis |
|
|
can direct Gram stain be useful for dx of N. gonorrhea in males
|
yes, not in females (due to prevalence of acinetobacter)
|
|
|
dz of n. gonorrhea
|
Acute urethritis, endocervix, ocular, rectal,
oropharynx |
|
|
recall transport for n. gonorrhea
|
charcoal swabs
|
|
|
dz for moraxella catarrhalis
|
Pneumonia, eye, sinus, otitis media
|
|
|
morphologic fx of moraxella catarrhalis
|
Direct gram stain of sputum
Polys and gram negative diplococci ockey puck colony oxidase positive DNA’ase positive Resistant to amp by beta lactamase |
|
|
name some gram positive rods (5)
|
cornyebacterium spp.
listeria bacillus spp (anthrax, b. cereus) Erysipelothrix Arcanobacterium |
|
|
morphologic fx of cornyebacterium
|
Catalase +, diphtheroid morphology, no spores
|
|
|
toxic effect of C. diphtheriae is mediated by
|
phage mediated toxin detected by Elek
immunoprecipitation procedure (not all are toxin producing) |
|
|
moraxella catarrhalis
|
Polys and gram negative diplococci
Hockey puck colony oxidase positive DNA’ase positive Resistant to amp |
|
what
|
gram stain of moraxella
|
|
what
|
elek test for C. diphtheriae
|
|
what
|
elek2
|
|
|
what
|
bull's neck in C. diptheriae
|
|
|
two tests for C. diptheririae
|
- Cysteine tellurite agar (modified Tinsdale) for
isolation – black colonies with brown halos - Loefflers slant + stain with methylene blue to look for metachromatic granules |
|
what
|
Cysteine tellurite agar (modified Tinsdale) for
isolation – black colonies with brown halos, reduction of tellurite selective and differentiation |
|
visual review of gram stain
|
for review
|
|
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on a loeffler's slant, what would you see for c. diphtheriae
|
metachromatic granules
egg containing loeffler slant, look for bug |
|
what
|
corynebacterium spp. chinese letters
|
|
|
classic desc of c. diphtheriae
|
diphtheritic pseudo membrane adherent in
throat in diphtheria |
|
|
Corynebacterium jekeium problems
|
patients with plastic catheters and indwelling
devices, normal skin flora (lipophilic) only sus to vanc and tetra |
|
|
Corynebacterium urealyticum clinical findings
|
Rapidly urease positive diphtheroid found in
urine cultures – alkaline encrusted cystitis |
|
|
morphologic/enzymatic fx of bacillus
|
boxcar, catalase +, spores
|
|
what
|
bacillus anthracis
|
|
what
|
B. anthracis
|
|
what
|
b anthracis - black eschar skin lesions
|
|
|
medusa head colonies on BAP
|
B. anthracis
|
|
what
|
B. anthracis medusa head
|
|
|
cf b anthracis vs. b cereus
|
b. anthracis - non-hemolytic, non-motile,
b cereus - beta hemolytic and motile |
|
|
morphologic fx of listeria
|
catalase positive,
beta hemolytic colony intracellular pathogen in macrophages |
|
|
tumbling motility
|
listeria >25 than >35
grows on cold |
|
|
who is listeria is most concern for
|
pregnant ( ingest-sepsis-stillbirth) or
immune suppressed (CNS and sepsis) |
|
|
cf beta hemolytic strep vs. listeria
|
can look like beta hemo strep on gram strain
major difference: listeria is catalase + (NOT STREP!) different meds |
|
|
umbrella stab
|
listeria
|
|
|
Erysipelothrix rhusiopathiae –
|
catalase negative, alpha hemolytic colony
***only G+R that produces H2S (TSI)* associated iwth endocarditis |
|
|
Arcanobacterium hemotyticumbeta
|
hemolytic, catalase negative
causes pharyngitis* trick - could be confused with Strep pyogenes (but rod) |
|
|
definition Enterobacteriaceae
|
Glucose fermented, Oxidase = negative and
Nitrate is reduced to nitrite |
|
|
what are lactose fermenters
|
turn pink on MacConkey agar from lactose fermentation
|
|
|
E.coli – results for lactose and indole
|
Lactose positive and indole positive (green sheen on EMB agar)*
|
|
|
common pneumonia in alcoholics
|
Klebsiella pneumoniae –
|
|
|
morphology of kleibsella on plate
|
mucoid colony,
|
|
|
sputum appearance for klebsiella
|
currant jelly sputum*
|
|
|
proteus spp - fermentation vs. no
|
nonlactose fermenters
|
|
|
difference between Proteus spp - P. vulgaris and P. mirabilis
|
Indole positive – P. vulgaris
Indole negative – P. mirabilis |
|
|
Serratia marcescens
|
has red pigment/infection in immune suppressed
|
|
what
|
proteus swarming
|
|
what
|
serratia marcescens
|
|
|
clinical sx of salmonella
|
Diarrhea +/- fever – polys in the stool
Can become bacteremic in immune suppressed (HIV) |
|
|
selective media for salmonella
|
Selective media – Hektoen and SS
|
|
|
how to type salmonella
|
Identification based on biochemical reactions and
serologic typing “Kaufman White typing scheme” |
|
|
what is "Kaufman White typing scheme” for- what bug group and what properties about that bug group
|
Salmonella
O Somatic antigen – cell wall H flagellar antigens – 2 phases h1 h2 Vi capsular antigen –Found in S. typhi only |
|
|
clinical setting for S. typhi
|
different than other salmonella, Typhoid fever – sepsis and fever
|
|
|
antigens on S. typhi: how to evaluate for capsular vs. somatic antigen
|
Vi capsular antigen, can mask D
Can boil solution of organism for 15 minutes to destroy the VI and expose the somatic antigen |
|
|
tsi and salmonella
|
lots of H2S production with salmonella except with S. typhi (just a Moustache of H2S in the TSI tube)
|
|
|
cf salmonella and shigella
|
shigella is nonmotile and doesn't produce H2S (salmonella is motile and produces H2S on TSI slant)
|
|
|
4 species of shigella based off antigens
|
S. boydii Group C
S. dysenteriae Group A S. flexneri Group B S. sonnei Group D |
|
|
clin findings in yersinia
|
Cause of diarrhea
-Major reservoir – swine -Septicemia in iron overload syndromes -Mesenteric adenitis – RLQ pain mimics apy |
|
|
two bugs that grow well at 4c
|
yersinia and listeria
|
|
|
Has been associated with banked blood infections – Transfusion Rxn
|
Yersinia
|
|
|
Bipolar staining “safety pin” gram negative
|
Yersinia pestis - plague (GNR)
|
|
|
clinical sx of Y pestis
|
Flea bite leads to Bubonic form with painful
buboes (lymph node swelling) Pneumonic form- bacteremic spread or patient to patient fatality >=50% |
|
what
|
Yersinia pestis safety pin
|
|
|
vibrio chlorae sx
|
Rice water stools – mucus flecks in liquid stool
|
|
|
mechanism of vibrio cholera pathogenicity
|
Toxin – receptor on epith cell –activates adenylate
cyclase – inc cAMP – hyper secretion of NaCl and H20 |
|
|
lab tests for vibrio cholera
|
Halophilic – salt loving , 1% salt enhances growth
Selective media – TCBS = thio citrate bile sucrose agar, turns yellow due to sucrose fermentation |
|
|
most virulent form of vibrio cholera
|
01 most virulent – classic & El Tor
|
|
|
cf seagulls to commas
|
seagulls - campylobacter
commas - vibrio |
|
|
Vibrio parahemolyticus - clinical setting
|
Sucrose negative – green on TCBS
Diarrhea from ingestion of raw fish and shellfish |
|
|
vibrios on TCBS
|
vibrio cholera - yellow
vibrio parahemolytica - green vibrio vulnificus - yellow or green, lactose + |
|
|
clinical setting for Vibrio vulnificus **
|
-Causes painful skin lesions with muscle necrosis on
lower extremities and septicemia in patients with pre existing liver disease 50% fatality rate -Ingestion of raw oysters and shellfish from coastal waters |
|
|
Glu nonfermenters/oxidase -
|
usually noscomial
|
|
|
morphology acinetobacter
|
Gram negative cocco baccilli – big diplococci
|
|
|
two types of acinetobacter - how to distinguish
|
Acinetobacter baumannii – gluc oxidizer
Acinetobacter lwoffi – gluc non oxidizer |
|
|
Stenotrophomonas maltophilia lab findings
|
rapid maltose oxidizer
Gram negative bacillus |
|
|
imipenem - this shows up
|
supercolonizer - Stenotrophomonas maltophilia
|
|
|
how know if if a gram negative rod
ferments, or oxidizes a sugar |
Oxidative/Fermentative (OF)
sugar reactions |
|
|
fermentation how work
|
anaerobic, can work under oil
|
|
|
O/F sugar tubes
|
two tubes, one with oil, one without, green indicator dye
if turns yellow in both tubes = fermenter if turns yellow in one tube w/o oil= assimilation if no yellow, but growth = oxidizer |
|
|
pseudomonas lab properaties
|
Glucose non-fermenter/oxidase +
fluorescent pigment and blue green pigment (pyocyanin) Grape like odor Growth at 42*C (Ps fluorescens/putida – no growth at 42*)*** |
|
|
clinical settings for pseudomonas
|
Major pathogen in cystic fibrosis – in combination
with Burkholderia cepacia can cause major lung damage - Nosocomial pathogen |
|
|
Burkholderia cepacia
|
Dry , yellow colony, oxidase negative
|
|
|
Alkaligenes - property in lab
|
-sweet fruity odor
|
|
|
Flavobacterium (Chryseobacterium) clinical
|
F. meningiosepticum - meningitis outbreaks in NICUs
|
|
|
Hemophilus influenza clinical dz
|
cause of CNS, pulmonary, eye, ear…...infections
|
|
|
growth fx of Hemophilus influenzae
|
Growth factor requirement (X = hemin and V= NAD)
-Growth on choc agar not blood plates requires high level C02 - 15 – 20% resistance to Ampicillin by beta lactamase production |
|
|
what is Hemophilus parainfluenza
|
– requires V factor, usually normal flora
|
|
|
Hemophilus aphrophilus - clinical dz, requirements for lab
|
does not require X or V factor, cause of abscesses (liver, lung, brain) & endocarditis
|
|
|
Hemophilus ducreyi growth, clinical, lab findings
|
– requires X factor (Chancroid - venereal disease)
|
|
|
what organisms can be found in satellites
|
H. influenzae, Abiotropha (nutrient variant Strep)
|
|
|
HACEK group
|
Haemophilus aphrophilus
Actinobacillus actinomycetecomitans Cardiobacterium hominis Eikinella corrodens Kingella kingii |
|
|
endocarditis, gram negative rod
|
HACEK
|
|
|
HACEK organisms and differential staining
|
Haemophilus aphrophilus = oxidase neg,
catalase neg Actinobacillus actinomycetecomitans = oxidase neg, catalase pos Cardiobacterium hominis = oxidase pos Eikinella corrodens = oxidase pos, pits BAP Kingella kingii = oxidase pos, hemolytic on BAP |
|
|
HACEK group
|
Oral flora – pathogens of endocarditis, can require 2-4 days to grow in blood cultures
|
|
|
Bordetella pertussis clinical
|
whooping cough
|
|
|
Bordetella - lab requirements/tests
|
Direct detection or ID by Fluorescent antibody stain
Charcoal containing media for transport and culture – Regan Lowe Charcoal agar |
|
|
gram stain for bordetella
|
Tiny gram negative coccobacillus
|
|
|
sx of whooping cough
|
3 stages of disease –(1)Prodromal (2) Catarrhal (3)
Paroxysmal Prodromal most contagious Cough caused by toxin adhering to bronchial epithelial cells, can last for months, esp deadly to young children |
|
|
how detect bordetella
|
Nasopharyngeal swab for culture
|
|
|
Pasteurella multocida: source
|
Cat and Dog bites/normal flora in animal’s mouth
|
|
|
Pasteurella multocida growth/test findings
|
Small gram negative coccobacilli
Grows on blood / not MacConkey agar Sensitive to penicillin / Oxidase positive |
|
|
two dog bite organisms
|
Pasteurella multocida (small) or Capnocytophyga
canimorsis (pleomorphic) |
|
|
Brucella
|
-Very small gram negative coccobacilli
-Castaneda biphasic blood culture historically used for culture – hold 14-21 day – now use Bactec automated system |
|
|
brucella
|
B. abortus – raw cow milk
B. melitensis – raw goat milk, feta cheese B. suis – pigs B. canis - dogs |
|
|
brucella
|
hip and knee pain, bone and joint pain
|
|
|
gram stain campylobacter
|
Small curved gram negative bacilli – shaped like sea gull wings
|
|
|
clinical sx/setting C jejuni
|
agent of diarrhea
Related to undercooked poultry ingestion Guillain Barre syndrome as sequelae |
|
|
growth characteristics C jejuni
|
-requires selective media containing antibiotics (Skirrow’s blood agar), put
-42*C in microaerophilic atmosphere |
|
|
cf Campylobacter jejuni, c. fetus
|
C. jejuni – grows at 37*C and 42*C
C. fetus - grows at 37*C and 25*C |
|
|
clinical setting Campylobacter fetus
|
blood culture pathogen in the immune
suppressed host |
|
|
Capnocytophyga morphology
|
Fusiform shaped gram negative rods – very
pleomorphic Oxidase negative, Catalase negative Gliding motility, fingerlike projections from colonies |
|
|
Francisella tularensis
|
Strongly associated with skinning rabbits with bare hands
|
|
|
Francisella tularensis sx
|
Can cause painful skin lesions – lymph nodes - leading to bacteremia (ulcerogladular tularemia) Pneumatic
|
|
|
culture requirement Francisella tularensis
|
cysteine
|
|
|
h pylori identification
|
Rapidly!! And strongly urease positive –
this test is used for identification from antral biopsy tissue Difficult to grow stool ag |
|
|
media for legionella
|
“Buffered Charcoal Yeast Extract agar”
|
|
|
trick of legionella to id
|
not routine gram, need silver or different counterstain to gram
|
|
|
what requires cysteine for growth
|
legionella, Francisella tularensis
|
|
|
main way to detect L. pneumophila
|
Urinary antigen test to detect L. pneumophila
type I infection only |
|
|
legionella - setting
|
water
|
|
|
what to use to treat legionella
|
Erythromycin
|
|
|
Bacteria without cell walls
|
Mycoplasma and Ureaplasma - cell membrane only
|
|
|
requirement for mycoplasma/ureaplasma
|
Media and transport must contain sterols to
protect the membrane. |
|
|
M. pneumoniae – clinical setting
|
community acquired pneumonia
|
|
|
M. hominis –clinical setting, appearance
|
fried egg colony, vaginitis, cervicitis, postpartum sepsis, neonatal infections , pre rupture of membranes
|
|
|
U. urealyticum - lab, clinical
|
rapid urea hydrolysis in broth, NGU, upper genital tract
brillo pads |
|
|
tough to grow organisms
|
Bartonella spp
Chlamydiae spp Ehrlichia spp |
|
|
bartenella bacilliformis
|
cat scratch disease, bacillary angiomatosis (vascular
proliferation) & Oroyo fever |
|
|
disease assoc: Bartonella quintana
|
trench fever - Quintan fever, 5 day fever, think WWI
|
|
|
Chlamydiae trachomatis – clinical disease
|
trachoma (eyelid granularity due to LA) and STD
Serovars L1,L2,& L3 = Lymphogranuloma venereum (infection of lymphatics and lymph nodes |
|
|
C. trachomatis lab findings
|
spin down shell vial culture, probe,
amplification |
|
|
C. psittaci- clinical dz and associated etiology
|
psittacosis, pneumonia, parakeets (3 P's)
|
|
|
where is erlichia found
|
midwest, tick bite
|
|
|
sx of erlichia
|
fever, leukopenia, thrombocytopenia, elevated
serum aminotransferases |
|
|
Borrelia burgdorferi - dx, tick
|
lyme, ixodes
spirochete |
|
|
Borrelia recurrentis dz
|
relapsing fever - human body louse
spirochete |
|
|
Leptospira interrogans
|
Leptospirosis, rats and other animals
water association allowing water that has been contaminated by animal urine to come in contact with unhealed breaks in the skin, the eyes, or with the mucous membranes spirochete |
|
|
Treponema pallidum - disease association
|
syphilis, spirochete
|
|
|
Bacteroides fragilis group
|
anaerobe - growth in the presence of bile, esculin positive, main organism in human bowel, pleomorphic gram negative rod
|
|
|
Bacteroides frag group
|
B. fragilis
B. ovatus B. distansonis B. uniformas B. thetaiotamicrons – only indole positive in this B. uniformis B. vulgatus |
|
|
Fusobacterium - in lab
|
Fusiform gram negative bacilli, spindle shaped with pointed ends
|
|
|
Fusobacterium - clinically
|
Associated with mouth and respiratory tract abscesses
|
|
|
Clostridium spp in lab
|
Gram positive bacilli (boxcar shaped) with spores
|
|
|
Clostridium perfringens on plate
|
double zone of beta hemolysis
|
|
|
test to remember for clostridium perfringens
|
reverse camp test +
|
|
|
Clostridium botulinum clinically
|
food borne toxin ingestion in adults
spore ingestion in small children flaccid paralysis |
|
|
Clostridium tetani clinically
|
rigid paralysis
Toxin enters due to penetrating skin injury |
|
|
Clostridum tetani in lab
|
tennis racket looking organism due to spore at the end
|
|
|
if see Clostridium septicum, what should you think of
|
organism in the blood associated with cancer
|
|
|
Clostridium difficle in lab
|
entertoxin A and Cytotoxin B,
Can detect B with cell culture and A and B with EIA or latex agglutination |
|
|
C difficle clinically
|
– cause of antibiotic associated colitis
|
|
|
Actinomyces in lab
|
Branching gram positive bacilli that do not form spores, capable of forming sulfur granules in tissue
|
|
|
A. israelii in lab
|
Bread crumb colonies in broth, molar tooth colony on agar plates.
|
|
|
Actinomyces israelii clinically
|
associated with oral, thoracic, and abdominal infections, IUD infections.
|
|
|
Propionibacterium acnes in lab
|
Anaerobic diphtheroid – pleomorphic gram
positive rod, does not branch |
|
|
Propionibacterium acnes: clinical association
|
Can be pathogen in cerebral shunt infections – can cause shunt nephritis
|
|
|
disease associations: Francisella tularensis
|
– tularemia - vectors are ticks and deer flies,
disease is named after Tulare County, California (like san FRANCIS) |
|
|
disease association: Bordetella pertussis –
|
pertussis
|
|
|
disease association: H. ducreyi
|
chancroid
|
|
|
disease association: Pasteurella multocida
|
dog bite (and cats)
|
|
|
disease association: Capnocytophyga canimorsus
|
dog bite (and cats)
|
|
|
disease association: Legionella pneumophila
|
Legionnaire’s
|
|
|
disease association: Gardnerella vaginalis
|
Bacterial vaginosis, can
use human blood to culture, hemolytic colonies |
|
|
disease association: Helicobacter pylori
|
gastritis, ulcer
|
|
|
disease association: Calymnobacterium granulomatis
|
granuloma inguinale - painless genital ulcers
|
|
|
disease association: Streptobacillus moniliformis
|
rat bite fever (sodoku)
|
|
|
disease association: Bartonella
|
cat scratch
bacillary angiomatosis |
|
|
disease association: Borrelia burgdorferi
|
lyme
|
|
|
disease association: B. recurrentis -
|
Borreliosis - louse based, relapsing fever
|
|
|
disease association: Treponema pallidum
|
– syphilis
|
|
|
disease association: T. whippelii –
|
Whipples disease
|
|
|
disease association: Bacillus anthracis
|
– anthrax (black eschar)
|
|
|
disease association: Erysipelothrix rhusiopathiae
|
erysipeloid (raw fish handler)
|
|
|
disease association: Beta Strep group A
|
erysipelas
|
|
what
|
erysipelas: sharply demarcated skin infection, infants, elderly, orange peel, caused by beta Strep group A (s pyogenes)
|
|
what
|
erysipelothrix - probably would have trouble delineating from beta hemolytic group A strep (s pyogenes) if only clinical, but note on hands, associated with handling raw fish
|
|
what
|
bacillary angiomatosis
|
|
what
|
bacillary angiomatosis
|
|
reverse camp test for review
|
review
|
|
what test, what for
|
umbrella motility stab test
listeria - left is negative control, right is listeria |
|
|
what is the only gram positive rod that produces H2S on a TSI
|
Erysipelothrix rhusiopathiae
|
|
gram positive rod with above finding what is it
|
H2S on TSI, Erysipelothorix
|
|
emb agar, what bug
|
e coli
|
|
|
what is emb agar
|
Eosin-methylene blue (EMB) agar - differentiates between sugar fermenters and nonfermenters
|
|
what
|
kleibsella pneumoniae, mucoid
|
|
|
enterobacteraciae - Non lactose fermenters (clear on MacConkey's
|
proteus, serratia, salmonella, shigella, yersinia (?)
|
|
|
name three strong lactose fermenters in enterobacteriaceae family
|
Escherichia, Klebsiella, Enterobacter
|
|
|
name five enterobacteriaceae that are usually negative on macConkey's (nonlactose fermenters)
|
- Proteus
- Salmonella -Shigella - Serratia (can be weak) - Yersinia (is a sucrose fermenter though) |
|
|
three common characteristics to enterobacteriaceae (with some exceptions)
|
- glucose is fermented
- cytochrome oxidase is negative - nitrate is reduced to nitrite |
|
|
name two curved gram negative rods, oxidase-postive fermenters
|
campylobacter
vibrio |
|
|
selective media for vibrio
|
TCBS - Selective media – TCBS = thio citrate bile sucrose
agar, turns yellow due to sucrose fermentation (vibrio is a glucose and sucrose fermenter) |
|
what
|
tcbs for positive vibrio
|
