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167 Cards in this Set

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General Characteristics of Enterobacteriaceae
Gram negative bacilli
oxidase negative
MacConkey positive
All Glucose fermenters
most reduce nitrate to nitrite
Genera of Enterobacteriaceae
Citrobacter Hafnia
Edwardsiella Klebsiella
Enterobacter Proteus
Escherichia Salmonella
Serratia Yersinia
Shigella
Fermentation
Oxidation reduction reaction that makes pyruvate.
Tested with pH changes
Most bacteria that metabolize carbohydrates are facultative anaerobes
Methyl Red test
Mixed acid fermentation
large amount of acid causes pH to drop which causes color change
detects prduction of strong acids from glucose fermentation
Voges-Proskauer
Butylene glycol pathway (tests for glucose fermentation)
acetyl methyl carbinol
acetoin
Positive VP=negative methyl red
Gas Production
all gas producers form acids
Durham tubes or TSI
Lactose Fermentation
two enzymes necessary
B-galactosidase and B-galactose permease
ONPG test
tests for B-galactosidase
ONPG is colorless
B-galactosidase cleaves ON from PG causing test to turn yellow
Cytochrome oxidase
iron-containing hemoproteins
tetramethyl-p-phenylenediamine dye accepts the final electron instead of oxygen and causes color change
reduced dye-colorless
oxidized dye-indophenol blue formation
Nitrate reduction
some reduce nitrate to nitrate but some go all the way
nitrate to nitrite will turn red immediately
if negative add zinc
if turns red, still negative
remains clear--positive for reduction of nitrate
Indole
tests for tryptophanase
add kovac's reagent
red=positive
Citrate utilization
tests to see if organism can use sodium citrate as only carbon source

blue=positive
Urease production
can organism hydrolyze urea and produce ammonia
pink=positive
Decarboxylation of amino acids
decarboxylation enzymes remove CO2 to form alkaline-reacting amines
bright purple=positive
Phenylalanine deaminase production
detects oxidative deamination of phenylalanine
green=positive
Hydrogen Sulfide production
detects organisms ability to produce H2S from sulfur-containing amino acids or other compounds
black precipitate
Escherichia coli

lactose fermenter
most commonly recovered organism
H2S negative, methyl red positive
E. coli O157:H7
shigella-like toxins
dysentery
lack of sorbitol fermentation on special MacConkey agar
Escherichia coli

symptoms
sepsis, endotoxin enduced shock, UTI's (most common S. sapro second most)
wound infections, gastroenteritis, meningitis in newborns, pneumonia in petri dish people
Enterotoxigenic E. coli

ETEC
traveler's diarrhea
watery stool
NO Blood or Mucous
abdominal cramps
Enteropathogenic E. coli

EPEC
babies
low grade fever
diarrhea with mucous NO BLOOD
Enteroinvasive E. coli

EIEC
dysentery, fever, colitis
BLOOD, MUCOUS and WBCs in stool
Enterohemorrhagic E coli

EHEC
diarrhea, abdominal pain
BLOOD, NO WBCs, No fever
Enteroaggregative

EaggEC
watery diarrhea, some abdominal pain, dehydration, vomiting

looks like ETEC
Shigella

biochemically inert
lactose negative
rarely slow lactose fermenters, rarely produce gas
most communicable form of bacterial diarrheas
Shigella sonnei
ONPG positive
most common diarrhea in US
mild, some may be asymptomatic
Shigella dysenteriae
cannot ferment mannitol
least common in US most common 3rd world countries
Shigella flexneri and Shigella boydii
difficult to differentiate biochemically
S. flexneri decarboyxlates ornithine
Edwardsiella tarda

reptiles, fresh water fish
H2S positive
non-lactose fermenter
wounds from trauma, iron availability increases severity of infection
Salmonella typhi

all others are hard to distinguish biochemically
trae amounts of H2S
Citrate negative
ONPG negative
negative for gas


report as either "S. typhi" or "Salmonella spp not typhi"
Salmonella infections
Typhoid fever
contaminated food, water, milk
Non-typhi
common in US from contaminated poultry or eggs
some contact with reptiles
Typhoid fever
fever and constipation first 2 weeks, positive blood, negative stool
after 2 weeks, positive stool, negative blood, diarrhea begins
Enteric fever
caused by any strain of Salmonella
usually mild fever and diarrhea
Gastroenteritis
most frequent manifestation
low grade fever, mild to severe diarrhea
Bacteriemia (bacteria in blood) and Septicemia (bacteria in blood causing infections in other places)
can occur without GI symptoms
High fever with positive blood cultures
Carrier states (Salmonella)
usually seen in people with previous infection although may just carry.
Can shed for up to a year after infection
Recovery and identification of Salmonella
Hektoen enteric media will be colorless with black centers
fluorescene tests
Citrobacter
H2S positive
Grow in KCN
lysine decarboylase negative
ONPG positive
Citrobacter freundii
usually found in hospitalized patients or with chronic conditions
Citrobacter koseri (diversus)
infant meningitis
1/3 survive and 3/4 of those will have neurological damage
Klebsiella pneumoniae

indole negative
mucoid
nonmotile
ornithine decarboyxlase negative
slow urea
classic pneumonia tissue necrosis and hemorrhage
thick, brick red sputum and mucoid or thin and slimy
Klebsiella oxytoca
indole positive
found in feces, blood
nosocomial infections..

all Klebsiellas are highly resistant to antibiotics
Enterobacter
differentiate from Klebsiella because

MOTILE, Ornithine positive

Chromosomally encoded B-lactamase that interferes with susceptibility testing..no PCN use
E. aerogenes and E. cloacae are most common
Normal intestinal flora
opportunistic infections of other sites

E. sakazaki neonatal meningitis high mortality rate bright yellow pigment
Hafnia alvei
smells like poop

pathogenesis uncertain
Genus Serratia
differentiate based on
lipase, gelatinase, DNAse
resistant to cephalothin and colistin
Serratia marcescens
opportunistic pathogen
pneumonia and septicemia in leukemia patients
Red on MacConkey at room temp
Tribe Proteeae
Proteus, Morganella, Providencia
PDA positive only ones of Enterobacteriaceae that are
Proteus mirabilis

PDA positive
swarming motility
most H2S positive
UTIs and wound infections
indole neg
esculine neg
salicin neg
Proteus vulgaris

most H2S positive
immunosupressed hosts on longterm antibiotics
indole positive
esculine positive
salicin positive
Morganella morganii

trehalose negative
PDA positive
UTIs, wounds, occasionally diarrhea
Yersinia pestis

urea negative
ornithine neg
rodents
urban plague (rats) sylvatic plague (US from rodents)
transfer to humans from flea bite
causes pneumonic(bad) and bubonic plague
Yersinia psudotuberculosis
birds
mesenteric lymphadenitis (infected lymph nodes)
underlying disorders may cause septicemia with high mortality rate
Yersinia entercolitica

associated with transfusion reactions
grow in refrigeration produces endotoxin after 2-3 week lag phase
lakes and reservoirs
diarrhea, lymphadenopathy, pnumonia
oral-digestive route of infection
chitterling cleaning (pig intestines)
CIN agar (cefsoludin-irgasan-novobiocin) makes bullseye pattern
General Identification of Haemophilus
small non-motile Gram negative rods (coccobacillary)
oxidase positive
catalase negative

require X and V factors
X-factor
tetrapyrrole compounds provided by iron containing pigments such as hemin and hematin
V-factor
NAD or NADP
found in blood but may be hydrolyzed by enzymes found in intact sheep RBCs. so V factor requiring organisms don't grow well on SBA but grow on chocolate just fine
Satellite colonies
some organisms release x and v factors as they grow (S. aureus) so streak whole plate with haemophilus and a line of S. aureus. X factor released with cells lyse from b-hemolysis and S. aureus releases v factor as grows
Haemophilus influenzae
2 categories
typeable(capsule) and nontypeable (no capsule)
Haemophilus influenzae

virulence factors
capsule (types a,b,c,d,e, or f) and bacterial attachment to epithelial cells
Haemophilus influenzae type b
vaccinate against this
most common type
2 months to 5 years
most common under 2 years
Haemophilus influenzae
Meningitis
just less than 1/2 of all meningitis cases are H. influenzae
in adults (complication of preexisting state typeable and nontypeable found equally in adults)
Haemophilus influenzae
Meningitis in Children
children under 5
type b most common cause between 1 month and 2 years
2years and 5years, H, influenzae and N. meningitidus are equal
HIGHLY contagious
Complication of CSF shunts (nosocomial infections)
Haemophilus influenzae
Epiglottitis
second most common disease state from H. influenzae
chldren age 2-7
rapid onset of symptoms
laryngeal edema
Haemophilus influenzae
Otitis media
most nontypeable form

if type b have meningitis and bacteremia too
S. pneumonia and H. influenzae most common in acute ear infections
6 months to 2 years
Haemophilus influenzae
Sinusitis
children and adults
secondary infections after viral infection
usually nontypeable
Haemophilus influenzae
Upper Respiratory tract infections
previous infection with virus makes more susceptible
Haemophilus influenzae
Tracheobronchitis
chronic bronchitis
can become purulent sputum and acute febrile tracheobronchitis
non-typeable H. influenzae
can develop into pneumonia
Haemophilus influenzae
Pneumonia
complication of bronchitis
usually type b
nontypeable or other than b are elderly patients with underlying respiratory problems
Haemophilus influenzae
Bacteremia
common manifestation in early stages of meningitis
secondary complications: especially maternal-fetal or maternal-perinatal transmission
Haemophilus parainfluenzae
H. aphrophilus and paraphrophilus
Endocarditis

rarely H. influenzae
young to middle-age adults
upper respiratory tract or dental problems
non-typeable Haemophilus influenzae and H. parainfluenzae

urogenital, maternal, and perinateal infections
nongonococcal urethritis, infections of female genital tract, postpartum bacteremia and neonatal sepsis

pre-existing conditions or IUDs
Haemophilus influenzae biogroup aegyptius

Conjunctivitis
pink eye
Brazilian pupuric fever
subgroup of strains looking like H. aegyptius
high fever, abdominal pain, vomiting, petechiae within 3 days
vascualr collapse, hypotensive shock, and death
children had conjunctivitis previously
only seen in Brazil and Australia so far
Haemophilus ducreyi

Chancroid
sexually transmitted disease
genital and perianal ulcers tender inguinal lymphadenopathy (buboes)
soft chancre, look different than syphillus
Immunologic techniques for Haemophilus
latex agglutination and enzyme immunoassay
direct test body fluid for antigens
Isolation in culture of Haemophilus
don't grow well on SBA
Rabit or horse blood or chocolate
Capnophilic
usually use quad plates to identify
H. influenza X&V factor
H. haemolyticus X&V, hemolytic
H. parainfluenza
H. parahaemolyticus only v
but parahaemolyticus is hemolytic on HBA
H. ducreyi only X
H. aphrophilis will grow anywhere
ALA-porphyrin test
checks for ability to synthesize proporphyrin intermediates from ALA

if can don't need X-factor
if can't do need X-factor
H. ducreyi
catalase negative
oxidase positive Gram negative coccobacilli
Mueller-Hinton agar supplemented with IsoVitalex and vancomycin
can use RapID-NH to identify
Haemophilus antibiotic susceptibility
resistant to ampicillin and chloramphenicol
Haemophilus prevention
vaccines for H. influenza b
vaccination at 2 months standard
Rifampin chemoprophylaxix common for household contact
HACEK
Haemophilus aphrophilus
Actinobacillus actinomycetemcomitans
Cardiobacterium hominis
Eikenella corrodens
Kingella species
Fastidious Gram negative bacilli
all part of normal flora of oropharyngeal or urogenital tracts
2-3 days to 2 weeks to grow
chocolate or blood agar
DO NOT grow on MacConkey, EMB or other enteric media
Capnophilic
Haemophilus aphrophilus/paraphrophilus
aphrophilus--only species that doesn't require X and V factors
paraphrophilus--requires V and has positive ALA test
Haemophilus aphrophilus/paraphrophilus

Identification
3 days to grow.
ONPG positive
catalase negative
make acid from glucose and lactose
Haemophilus aphrophilus/paraphrophilus

Differentiation
aphrophilus-not x or v factor dependent
ALA positive
sucrose, maltose, mannose negative

paraphrophilus--V factor dependent, ALA positive
sucrose, mannose, maltose positive
Haemophilus aphrophilus/paraphrophilus

Antimicrobial susceptibility
some resistance to PCN and ampicillin noted
Actinobacillus actinomycetemcomitans

oral flora
a, b, c, d and e types
co-isolated with Actinomycetes
subacute endocarditis (valve problems previously)
localized jevenile periodontitis (11-20is)
produce leukotoxin
Papillon-Lefevere syndrome
Actinobacillus actinomycetemcomitans

Culture characteristics
48-72 hours on blood& chocolate
star shaped colonies after a week
ferment glucose, fructose, mannose, catalase positive and reduce nitrate
Actionbacillus ureae
petri dish people
pleomorphic gram negative rods with filaments
24 hours on blood in CO2
urease positive
all amino acid tests negative
Cardiobacterium hominis
endocarditis
previously damaged heart valves
prior dental work
grows in 3-5 days with constant subculturing
gram variable
may be neg in middle and positive at poles
Indole positive in broth
pits agar, treated PCN
Eikenella corrodens

family Neisseriaceae

Virulence factors
adherance to epithelial cells RBC agglutination, pili
outer membrane causes premature release of lysozyme from macrophages
slime layer
Eikenella corrodens
causes infections of head and neck
bacteremia in IV drug users
pale yellow, smells like bleach, pits agar, needs x if grown aerobically
variable with PCN and cephalosporins
Kingella spp and Suttonella spp
Normal upper erspiratory and genitourinary tract flora
K. kingae infects cardiac tissue, valvular tissue, skeletal tissue
seen in bacteremia, endocarditis and joint infections
poor oral hygiene
Kingella spp and Suttonella spp

Culture characterisitics
Plump gram negative rods on SBA and chocolate
pairs or short chains
K. kingae is b-hemolytic on SBA
oxidase postive, catalase neg
multiple colonies on single culture. pit agar
S. indologenes indole pos

resistant to clindamycin, erythromycin, lincomycin and vancomycin
Non Fermenting gram negative bacilli
cannot utilize carbohydrates by fermentation pathways.
Oxidizers or Asaccharolytic (don't use carbohydrates)
Non Fermenting gram negative bacilli
usually infections caused by wounds or underlying conditions
found everywhere. Nosocomial infections
Differentiation from Enterobacteriaceae
Enterobacteriaceae utilize glucose with or without oxygen
use Embden-Meyerhof pathway
use lactate, mixed acids, butylene glycol

NON-FERMENTERS cannot processes these things
Presumptive identification of Non-fermenters
gram negative bacilli that do not ferment carbohydrates
differentiate based on:
growth on MacConkey, oxidase reaction, oxidative use of carbohydrates, motility, nitrogen utilization, decarboxylation of amino acids, gelatin hydrolyzation
Grouping Non-fermenters
Growth on MacConkey
Oxidase Reaction
Oxidizer or non-oxidizer
Pseudomonads
motile
Usually oxidizer
Oxidase positive
Growth on MacConkey
reistant to most antibiotics
Nosocomial infections very common
Pseudomonas aeruginosa
most frequently isolated
moist, aerated environments
can grow in distilled water
motile, Oxidase+, MacConkey+, Oxidizer
B-hemolytic (sometimes) Characteristic odor and color
produces both pyocyanin and some pyoverdin
citrate +, growth at 42 degrees
slime layer and exotoxins
Cystic fibrosis patients
synergy with virus infections
Stenotrophomonas maltophilia
motile, water, sewage, plant decay
nosocomial infections in petri dish people
significant antibiotic resistance
oxidase-, MacConkey+, Oxidizer/non-utilizer
distinguished from Pseudomonas by lysine, DNAse + tests (and Oxidase)
Acinetobacter
Oxidase-, MacConkey +(u), non-utilizer (+/-), NON-MOTILE, FLN acid test
resistant to PCN and chloramphenicol
Alcaligenes
Oxidase+,MacConkey+,non-utilizer, motile, reduces nitrates to nitrites
A.faecalis-opportunistic pathogen fruity odor
Pseudomonas fluorescens
pyoverdin but not pyocyanin
Gelatinase positive
Burkholderia cepacia
Oxidase-, MacConkey+, oxidizer, non-fluorescent yellow pigment
nosocomila infections, endocarditis, pneumonia
lysine positive (differentiate from Pseudomonas) very antibiotic resistant
Methylobacterium
Oxidase+, MacConkey-, non-utilizer
methanol as carbon source
bacteremia and skin ulcers
found in sewage
Agrobacterium
non-fermentative (duh??)
Peritrichous flagella
plant pathogen (Crown gall disease)
indicated in endocarditis and catherter-related infections
Flavobacterium
infection in prmature infants and petridish people
indole positive (tube)
oxidizers, motile, oxidase+
F. meningosepticum PCN resistant..causes neonatal meningitis
Sphingobacterium
Oxidase+, MacConkey-, oxidizers
septicemia
have sphigophosphates in cellwall
Moraxella
Oxidase+, MacConkey-, non-utilizer
opportunist
can cause disease of respiratory tract and eyes
Dysgonic Fermenters
Need CO2 to ferment sugars
some classified as Capnocytophagia
indicated in septicemia from animal bites
Capnocytophagia
CO2 required for growth
Gram negative rods, normal mouth flora
gliding motility
juvenile peridontitis--Actinomycetes& Actinobacillus actinmycetemcomtans
DOG BITES
Female genital tract
Aminopeptidases-virulence
Resistant to aminoglycosides and drugs of MTM (vancomycin
yellow pigment, MTM, blood, chocolate
Fusiform or curved GNR oxidase and catalse neg
Streptobacillus moniliformis
wound infections rodent bites
rat bite or haverhill fever
7-10 day onset
can become chronic
serologic identification
PCN drug of choice
Pasteurella species
nonmotile, Gram negative
rods or coccobacilli, facultative anaerobes
oxidase +
catalase +
Alkaline phophatase +
reduce nitrate
Pasteurella multicida
animal bites (tigers, dogs, cats)
respiratory infection PDpeps
chocolate, blood NOT MacConkey
Capnophilic, Ornithine and Indole POSITIVE, urease NEG
susceptible to many antibiotics
Pasteurella pneumotropica
normal in resp tract of dogs, cats, rats and mice.
humans-traumatic exposure to animals
urease, indole, ornithine POS
some grow on MacConkey
Urease differentiates from multicida
Pasteurella haemolytica
domesticated animals
rare human infections
Grows on MacConkey, Indole and Urease Neg
Pasteurella aerogenes
oropharyngeal and intestinal flora of PIGS
MacConkey+, Indole-, Urease+
Pasteurella bettyae
genital ulcers
may be sexually transmitted
(how the hell do you get it? if it's normal in dog mouth)
Bordetella pertussis

small gram negative coccobacilli
require specialized media
whooping cough, highly contagious
lasts 6-8 weeks
swelling of epiglottis causes whooping sound
3 stages: prodromal 5-10 days post exposure (best chance to culture)
paroxysmal stage--7-14 days "whooping stage"
convalescent stage--4 weeks after onset
Bordetella pertussis
vaccines and virulence factors
before vaccine 5-10k deaths per year
DPT not used anymore
DPaT now (acellular pertussis)

pertussis toxin--virulence factor
Bordetella species
Culture characteristics
Nasopharyngeal or aspirates NO COTTON SWABS
Bordet-Gengou agar(high starch from potatoes) look like mercury and are b-hemolytic
Regan-Lowe media charcoal/horse blood, looks like mother-of-pearl
identified-fluorescent antibodies
resistant to tetracyline
(most species more resistant than pertussis)
Brucella species
undulant fever, Bang's disease.
LIVESTOCK
meningitis, endocarditis, osteomyelitis
Brucella species
Virulence
antigenic variation
smooth phase-resistant to killing by neutrophils
facultative intracellular organisms
contaminated meat or dairy products.
hide in macrophages til release..causes up and down fever spikes
Brucella species
Identification
blood and bone marrow specimens of choice
biosafety level 3 organism
bloodbroth/agar mix
CO2 requirements, H2S and urease production, growth in thionin blue and basic fuschin dyes and serological test
need combination therapy for weeks
Francisella tularensis
Fastidious gram negative coccobacilli
causes tularemia
ticks and biting flies
direct contact with blood or internal organs of infected animal, ingestion of infected meat, water or aerosols
highly contagious
seen in south central states
Fracisella tularensis
clinical significance
unknown virulence factors
ulceroglandular(tick bite lesion)
Gladular(no skin lesion, lymphadenopathy)
Typhoidal (fever, chills)
oculoglandular(conjuctivitis)
oropharyngeal(tonsillitis)
pneumonic(complication of other forms)
Francisella tularensis
serological or EIA
3-7 days on special media if will grow at all
blood-cysteine agar best choice
Thayer-Martin or chocolate with Isovitalex
oxidase negative, weakly catalase positive
aminoglycoside streptomycin
Bartonella species
immunocompromised patients especially HIV
Oroya Fever and Verruga Peruana
sandfly vector B. bacilliformis
restricted to Peru, Ecuador, and Columbia
Fever portion 3weeks-3months lasts a week or more then enters Verruga stage
characterized by lesions, pain in joints
Bartonella henselae and B. quintana

Bacillary angiomatosis
vascular proliferation
HIV infected patients red to purple nodules

BITES OR SCRATCHES FROM CATS
Bartonella henselae and B. quintana

peliosis
cystic, blood filled lesions throughout the parenchyma of infected organ
Bartonella henselae and B. quintana

fever and bacteremia
immunocompromised patients
usually detected histopathologically or by molecular methods
B. quintana

Endocarditis
culture negative endocarditis
Bartonella henselae

Cat-scratch disease (CSD)
lyphadenopathy in children and adolescents
prior exposure to cats
Bartonella species
Identification
cauliflower like colonies
5-15 days blood or chocolate in 5% CO2
curved rods, twitching motility
Molecular, immunological or GLC methods
BIOCHEMICALLY inactive
Susceptible to ampicillin, tetracyclines
Afipia species
associated with CSD too
A. felis
gram negative
oxidase+, motile rods
blood agar, rarely MacConkey
3-4 days at RT scat at 35degrees
urease positive
susceptible to aminoglycosides
Legionella species
non-spore forming narrow Gram negative rods, most motile
Require L-cysteine and iron salts for growth
buffered charcoal yeast extract or BCYE agar
Legionella species
diseases
Legionnaire's disease-pneumonia with 10-20% fatality rate
Pontiac fever-self-limiting, non-fatal respiratory disease
Wound abscesses, encephalitis, and endocarditis
Legionella species

clinical significance
L. pneumophilia
immunocompromised people at higher risk
Antibody testing for asymptomatic cases
middle age or older people
Legionella species
Pathology
severe pneumonia that may or may not include abscesses
facultative intracellular pathogens
spread by inhalation of aerosolized organisms
Legionella species
Culture characteristics
growth on BYCE, no growth on blood clue to legionella, but F. tularensis also does this
Legionella do not ferment or oxidize glucose
limited biochemical testing
Serotying useful
Legionella species
epidemiology
contracetd from exposure to wide variety of environmental sources, no evidence of person to person
3rd most common pneumonia (after S. pneumonia and H. influenzae)
nosocomial infections
showers and baths spread
AC units
grow in association with amebae. Giemsa stain, Antigen detection EIA
Erythromycin drug of choice
Campylobacter jejuni subsp jejuni
microaerophilic
curved or spiral, motile, non-fermentative and non-oxidative Gram negative bacilli--gullwings
cattle and swine transmitted via food, milk or water
chicken consumption
diarrheal disease in humans
Campylobacter coli
diarrheal disease in humans
same as jejuni
Campylobacter species
symptoms
abdominal pain, bloody diarrhea, chills, fever
self-limiting for a week
secondary--severe arthritis, meningitis, Guillain-Barre syndrome
Campylobacter species
Presumptive ID
Characteristic Gram stain
Gullwings, curved, s-shape or spiral from diarrheal stools
Wet prep for PMNs and bacteria--darting motility
some labs require before culture
Campylobacter species
Isolation
selective media and proper conditions
42degrees, 5% O2, 10%CO2, 85%N2
Liquid stools direct plating
formed, emulsified in PBS first
Campylobacter species
Isolation Continued.....
prep for isolation:
prepare turbid suspension in BHI broth, inoculate 2 CSM plates
centrifuge 1000g 5 minutes
filter, discard 1st 3 ml
1-2 drops of remaining to inoculate 2 chocolate plates
incumate one set of CSM and chocolate each at 42 and 35 in 5% O2, 85% N2, 10%CO2
Campylobacter-selective media
(CSM)

Campy-BAP
Brucella agar base
10% sheep blood
Vancomycin
Trimethoprim
Polymixin B
Cephalothin
Amphotericin B
Differentiate Campy species
both jejuni hydrolyze hyppurate and are resistant to cephalothin and susceptible to nalidixic acid
Campylobacter jejuni subsp doylei
diarrheal stools of children
susceptible to cephalothin
Arcobacter
aerotolerant Campylobacter
Helicobacter pylori
chronic antral gastritis, factor in pahtogenesis of peptic ulcers
isolated from tissue biopses
Urease method to measure excreted radioactive ammonia (less invasive)
small, gray, weakly b-hemolytic, Gram negative curved bacteria
Catalase+, Oxidase+, rapid urease reaction
Vibrionaceae
Non-enteric
glucose fermenting
Gram negative rods
Oxidase +
Motile with polar flagella
MacConkey+
fresh water and salt water habitat
Vibrio cholerae
undercooked seafood
epidemics--oral-fecal contamination of water
somatic antigens 01 and 0139
Vibrio cholerae
Pathogenesis
non-invasive
diarrhea caused by toxin
binds epithelial cells preventing uptake of water
10-30 rice water stools per day..electrolytes and water
rapid onset 15-60 minutes
fluids very necessary or death from dehydration occurs
kill with tetracycline, but toxin remains for hours
Resistance to SXT
bacteria flushed from system after 5 days
Non-cholera Vibrios
severe diarrheal symptoms, extraintestinal infections..some are invasive
wounds from infected marine water
Vibrio parahaemolyticus
gastroenteritis in humas after eating contaminated seafood
mild to moderate, self-limiting
extraintestinal infections from wounds
rehydration only treatment required
Vibrio vulnificus
very virulent. associated with wound infections
Septicemia and death reported after eating contaminated seafood 40-60% fatality rate
invasive. hepatic disease makes more susceptible
Isolation of Vibrios
must be kept moist
inoculate to SBA and MacConkey ASAP
gram stain and oxidase+ then transfer to thiosulfate citrate bile sucrose (TCBS) agar.
Direct detection of toxin by ELISA or latex agglutination
Isolation of Vibrios
continued
straight or curved gram negative rods from special media--presumptive for vibrio
rapid darting or star motility on wet mount
TCBS differential
V. cholerae is yellow
alkaline peptone water broth to enhance growth before TCBS plating
Vibrio colony characteristics
smooth, opaque and irridescent with greenish color on blood containing agars
sucrose fermenters yellow on TCBS (V. cholerae and some V. vulnificus)
nonsucrose fermenters are green
most V. vulnificus and V. parahaemolytics
Differentiation of Vibrios, Aeromonas, Plesiomonas and Chromobacterium
Growth and color on TCBS
Growth in O% salt (V. cholerae, Aeromonas, Plesiomonas, C. violaceum)
Growth in 6% salt (all vibrios)
Aeromonas and Plesiomonas will NOT grow on TCBS or in 6% NaCl
Treatment and prevention of non-cholera infections
no standard susceptibility methods
vaccines and chemopropylaxis suggested for cholera
2 oral vaccines available worldwild
Tetracycline or SXT given to household contacts only
no preventative for non-cholera vibrios
Aeromonas
Gram negative straight-not curved-rods
fresh and sometimes sea water
coldblooded aquatic animals
tap and distilled water
wound infections, diarrheal disease, septicemia
Plesiomonas
pleomorphic gram negative rods--singly, pairs, short chains, long filamentous forms
P. shigelloides
surface waters and coldblooded animals
eating contaminated food
mild diarrhea, serious in petridish people
Chromobacterium
slightly curved, medium to long gram negative rods with rounded ends
C. violaceum bright purple pigment (interferes with oxidase test)