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167 Cards in this Set
- Front
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General Characteristics of Enterobacteriaceae
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Gram negative bacilli
oxidase negative MacConkey positive All Glucose fermenters most reduce nitrate to nitrite |
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Genera of Enterobacteriaceae
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Citrobacter Hafnia
Edwardsiella Klebsiella Enterobacter Proteus Escherichia Salmonella Serratia Yersinia Shigella |
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Fermentation
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Oxidation reduction reaction that makes pyruvate.
Tested with pH changes Most bacteria that metabolize carbohydrates are facultative anaerobes |
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Methyl Red test
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Mixed acid fermentation
large amount of acid causes pH to drop which causes color change detects prduction of strong acids from glucose fermentation |
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Voges-Proskauer
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Butylene glycol pathway (tests for glucose fermentation)
acetyl methyl carbinol acetoin Positive VP=negative methyl red |
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Gas Production
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all gas producers form acids
Durham tubes or TSI |
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Lactose Fermentation
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two enzymes necessary
B-galactosidase and B-galactose permease |
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ONPG test
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tests for B-galactosidase
ONPG is colorless B-galactosidase cleaves ON from PG causing test to turn yellow |
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Cytochrome oxidase
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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 |
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Nitrate reduction
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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 |
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Indole
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tests for tryptophanase
add kovac's reagent red=positive |
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Citrate utilization
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tests to see if organism can use sodium citrate as only carbon source
blue=positive |
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Urease production
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can organism hydrolyze urea and produce ammonia
pink=positive |
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Decarboxylation of amino acids
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decarboxylation enzymes remove CO2 to form alkaline-reacting amines
bright purple=positive |
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Phenylalanine deaminase production
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detects oxidative deamination of phenylalanine
green=positive |
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Hydrogen Sulfide production
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detects organisms ability to produce H2S from sulfur-containing amino acids or other compounds
black precipitate |
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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 |
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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 |
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Enterotoxigenic E. coli
ETEC |
traveler's diarrhea
watery stool NO Blood or Mucous abdominal cramps |
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Enteropathogenic E. coli
EPEC |
babies
low grade fever diarrhea with mucous NO BLOOD |
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Enteroinvasive E. coli
EIEC |
dysentery, fever, colitis
BLOOD, MUCOUS and WBCs in stool |
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Enterohemorrhagic E coli
EHEC |
diarrhea, abdominal pain
BLOOD, NO WBCs, No fever |
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Enteroaggregative
EaggEC |
watery diarrhea, some abdominal pain, dehydration, vomiting
looks like ETEC |
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Shigella
biochemically inert lactose negative |
rarely slow lactose fermenters, rarely produce gas
most communicable form of bacterial diarrheas |
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Shigella sonnei
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ONPG positive
most common diarrhea in US mild, some may be asymptomatic |
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Shigella dysenteriae
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cannot ferment mannitol
least common in US most common 3rd world countries |
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Shigella flexneri and Shigella boydii
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difficult to differentiate biochemically
S. flexneri decarboyxlates ornithine |
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Edwardsiella tarda
reptiles, fresh water fish |
H2S positive
non-lactose fermenter wounds from trauma, iron availability increases severity of infection |
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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" |
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Salmonella infections
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Typhoid fever
contaminated food, water, milk Non-typhi common in US from contaminated poultry or eggs some contact with reptiles |
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Typhoid fever
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fever and constipation first 2 weeks, positive blood, negative stool
after 2 weeks, positive stool, negative blood, diarrhea begins |
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Enteric fever
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caused by any strain of Salmonella
usually mild fever and diarrhea |
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Gastroenteritis
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most frequent manifestation
low grade fever, mild to severe diarrhea |
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Bacteriemia (bacteria in blood) and Septicemia (bacteria in blood causing infections in other places)
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can occur without GI symptoms
High fever with positive blood cultures |
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Carrier states (Salmonella)
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usually seen in people with previous infection although may just carry.
Can shed for up to a year after infection |
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Recovery and identification of Salmonella
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Hektoen enteric media will be colorless with black centers
fluorescene tests |
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Citrobacter
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H2S positive
Grow in KCN lysine decarboylase negative ONPG positive |
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Citrobacter freundii
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usually found in hospitalized patients or with chronic conditions
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Citrobacter koseri (diversus)
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infant meningitis
1/3 survive and 3/4 of those will have neurological damage |
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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 |
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Klebsiella oxytoca
indole positive |
found in feces, blood
nosocomial infections.. all Klebsiellas are highly resistant to antibiotics |
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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 |
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Hafnia alvei
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smells like poop
pathogenesis uncertain |
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Genus Serratia
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differentiate based on
lipase, gelatinase, DNAse resistant to cephalothin and colistin |
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Serratia marcescens
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opportunistic pathogen
pneumonia and septicemia in leukemia patients Red on MacConkey at room temp |
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Tribe Proteeae
Proteus, Morganella, Providencia |
PDA positive only ones of Enterobacteriaceae that are
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Proteus mirabilis
PDA positive swarming motility most H2S positive |
UTIs and wound infections
indole neg esculine neg salicin neg |
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Proteus vulgaris
most H2S positive |
immunosupressed hosts on longterm antibiotics
indole positive esculine positive salicin positive |
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Morganella morganii
trehalose negative PDA positive |
UTIs, wounds, occasionally diarrhea
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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 |
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Yersinia psudotuberculosis
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birds
mesenteric lymphadenitis (infected lymph nodes) underlying disorders may cause septicemia with high mortality rate |
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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 |
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General Identification of Haemophilus
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small non-motile Gram negative rods (coccobacillary)
oxidase positive catalase negative require X and V factors |
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X-factor
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tetrapyrrole compounds provided by iron containing pigments such as hemin and hematin
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V-factor
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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 |
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Satellite colonies
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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
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Haemophilus influenzae
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2 categories
typeable(capsule) and nontypeable (no capsule) |
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Haemophilus influenzae
virulence factors |
capsule (types a,b,c,d,e, or f) and bacterial attachment to epithelial cells
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Haemophilus influenzae type b
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vaccinate against this
most common type 2 months to 5 years most common under 2 years |
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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) |
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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) |
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Haemophilus influenzae
Epiglottitis |
second most common disease state from H. influenzae
chldren age 2-7 rapid onset of symptoms laryngeal edema |
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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 |
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Haemophilus influenzae
Sinusitis |
children and adults
secondary infections after viral infection usually nontypeable |
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Haemophilus influenzae
Upper Respiratory tract infections |
previous infection with virus makes more susceptible
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Haemophilus influenzae
Tracheobronchitis |
chronic bronchitis
can become purulent sputum and acute febrile tracheobronchitis non-typeable H. influenzae can develop into pneumonia |
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Haemophilus influenzae
Pneumonia |
complication of bronchitis
usually type b nontypeable or other than b are elderly patients with underlying respiratory problems |
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Haemophilus influenzae
Bacteremia |
common manifestation in early stages of meningitis
secondary complications: especially maternal-fetal or maternal-perinatal transmission |
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Haemophilus parainfluenzae
H. aphrophilus and paraphrophilus Endocarditis rarely H. influenzae |
young to middle-age adults
upper respiratory tract or dental problems |
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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 |
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Haemophilus influenzae biogroup aegyptius
Conjunctivitis |
pink eye
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Brazilian pupuric fever
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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 |
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Haemophilus ducreyi
Chancroid |
sexually transmitted disease
genital and perianal ulcers tender inguinal lymphadenopathy (buboes) soft chancre, look different than syphillus |
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Immunologic techniques for Haemophilus
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latex agglutination and enzyme immunoassay
direct test body fluid for antigens |
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Isolation in culture of Haemophilus
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don't grow well on SBA
Rabit or horse blood or chocolate Capnophilic usually use quad plates to identify |
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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 |
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ALA-porphyrin test
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checks for ability to synthesize proporphyrin intermediates from ALA
if can don't need X-factor if can't do need X-factor |
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H. ducreyi
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catalase negative
oxidase positive Gram negative coccobacilli Mueller-Hinton agar supplemented with IsoVitalex and vancomycin can use RapID-NH to identify |
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Haemophilus antibiotic susceptibility
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resistant to ampicillin and chloramphenicol
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Haemophilus prevention
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vaccines for H. influenza b
vaccination at 2 months standard Rifampin chemoprophylaxix common for household contact |
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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 |
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Haemophilus aphrophilus/paraphrophilus
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aphrophilus--only species that doesn't require X and V factors
paraphrophilus--requires V and has positive ALA test |
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Haemophilus aphrophilus/paraphrophilus
Identification |
3 days to grow.
ONPG positive catalase negative make acid from glucose and lactose |
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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 |
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Haemophilus aphrophilus/paraphrophilus
Antimicrobial susceptibility |
some resistance to PCN and ampicillin noted
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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 |
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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 |
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Actionbacillus ureae
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petri dish people
pleomorphic gram negative rods with filaments 24 hours on blood in CO2 urease positive all amino acid tests negative |
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Cardiobacterium hominis
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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 |
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Eikenella corrodens
family Neisseriaceae Virulence factors |
adherance to epithelial cells RBC agglutination, pili
outer membrane causes premature release of lysozyme from macrophages slime layer |
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Eikenella corrodens
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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 |
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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 |
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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 |
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Non Fermenting gram negative bacilli
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cannot utilize carbohydrates by fermentation pathways.
Oxidizers or Asaccharolytic (don't use carbohydrates) |
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Non Fermenting gram negative bacilli
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usually infections caused by wounds or underlying conditions
found everywhere. Nosocomial infections |
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Differentiation from Enterobacteriaceae
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Enterobacteriaceae utilize glucose with or without oxygen
use Embden-Meyerhof pathway use lactate, mixed acids, butylene glycol NON-FERMENTERS cannot processes these things |
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Presumptive identification of Non-fermenters
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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 |
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Grouping Non-fermenters
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Growth on MacConkey
Oxidase Reaction Oxidizer or non-oxidizer |
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Pseudomonads
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motile
Usually oxidizer Oxidase positive Growth on MacConkey reistant to most antibiotics Nosocomial infections very common |
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Pseudomonas aeruginosa
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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 |
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Stenotrophomonas maltophilia
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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) |
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Acinetobacter
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Oxidase-, MacConkey +(u), non-utilizer (+/-), NON-MOTILE, FLN acid test
resistant to PCN and chloramphenicol |
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Alcaligenes
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Oxidase+,MacConkey+,non-utilizer, motile, reduces nitrates to nitrites
A.faecalis-opportunistic pathogen fruity odor |
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Pseudomonas fluorescens
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pyoverdin but not pyocyanin
Gelatinase positive |
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Burkholderia cepacia
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Oxidase-, MacConkey+, oxidizer, non-fluorescent yellow pigment
nosocomila infections, endocarditis, pneumonia lysine positive (differentiate from Pseudomonas) very antibiotic resistant |
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Methylobacterium
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Oxidase+, MacConkey-, non-utilizer
methanol as carbon source bacteremia and skin ulcers found in sewage |
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Agrobacterium
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non-fermentative (duh??)
Peritrichous flagella plant pathogen (Crown gall disease) indicated in endocarditis and catherter-related infections |
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Flavobacterium
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infection in prmature infants and petridish people
indole positive (tube) oxidizers, motile, oxidase+ F. meningosepticum PCN resistant..causes neonatal meningitis |
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Sphingobacterium
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Oxidase+, MacConkey-, oxidizers
septicemia have sphigophosphates in cellwall |
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Moraxella
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Oxidase+, MacConkey-, non-utilizer
opportunist can cause disease of respiratory tract and eyes |
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Dysgonic Fermenters
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Need CO2 to ferment sugars
some classified as Capnocytophagia indicated in septicemia from animal bites |
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Capnocytophagia
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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 |
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Streptobacillus moniliformis
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wound infections rodent bites
rat bite or haverhill fever 7-10 day onset can become chronic serologic identification PCN drug of choice |
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Pasteurella species
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nonmotile, Gram negative
rods or coccobacilli, facultative anaerobes oxidase + catalase + Alkaline phophatase + reduce nitrate |
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Pasteurella multicida
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animal bites (tigers, dogs, cats)
respiratory infection PDpeps chocolate, blood NOT MacConkey Capnophilic, Ornithine and Indole POSITIVE, urease NEG susceptible to many antibiotics |
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Pasteurella pneumotropica
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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 |
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Pasteurella haemolytica
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domesticated animals
rare human infections Grows on MacConkey, Indole and Urease Neg |
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Pasteurella aerogenes
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oropharyngeal and intestinal flora of PIGS
MacConkey+, Indole-, Urease+ |
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Pasteurella bettyae
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genital ulcers
may be sexually transmitted (how the hell do you get it? if it's normal in dog mouth) |
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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 |
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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 |
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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) |
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Brucella species
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undulant fever, Bang's disease.
LIVESTOCK meningitis, endocarditis, osteomyelitis |
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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 |
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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 |
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Francisella tularensis
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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 |
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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) |
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Francisella tularensis
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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 |
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Bartonella species
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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 |
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Bartonella henselae and B. quintana
Bacillary angiomatosis |
vascular proliferation
HIV infected patients red to purple nodules BITES OR SCRATCHES FROM CATS |
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Bartonella henselae and B. quintana
peliosis |
cystic, blood filled lesions throughout the parenchyma of infected organ
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Bartonella henselae and B. quintana
fever and bacteremia |
immunocompromised patients
usually detected histopathologically or by molecular methods |
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B. quintana
Endocarditis |
culture negative endocarditis
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Bartonella henselae
Cat-scratch disease (CSD) |
lyphadenopathy in children and adolescents
prior exposure to cats |
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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 |
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Afipia species
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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 |
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Legionella species
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non-spore forming narrow Gram negative rods, most motile
Require L-cysteine and iron salts for growth buffered charcoal yeast extract or BCYE agar |
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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 |
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Legionella species
clinical significance |
L. pneumophilia
immunocompromised people at higher risk Antibody testing for asymptomatic cases middle age or older people |
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Legionella species
Pathology |
severe pneumonia that may or may not include abscesses
facultative intracellular pathogens spread by inhalation of aerosolized organisms |
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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 |
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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 |
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Campylobacter jejuni subsp jejuni
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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 |
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Campylobacter coli
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diarrheal disease in humans
same as jejuni |
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Campylobacter species
symptoms |
abdominal pain, bloody diarrhea, chills, fever
self-limiting for a week secondary--severe arthritis, meningitis, Guillain-Barre syndrome |
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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 |
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Campylobacter species
Isolation |
selective media and proper conditions
42degrees, 5% O2, 10%CO2, 85%N2 Liquid stools direct plating formed, emulsified in PBS first |
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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 |
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Campylobacter-selective media
(CSM) Campy-BAP |
Brucella agar base
10% sheep blood Vancomycin Trimethoprim Polymixin B Cephalothin Amphotericin B |
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Differentiate Campy species
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both jejuni hydrolyze hyppurate and are resistant to cephalothin and susceptible to nalidixic acid
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Campylobacter jejuni subsp doylei
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diarrheal stools of children
susceptible to cephalothin |
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Arcobacter
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aerotolerant Campylobacter
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Helicobacter pylori
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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 |
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Vibrionaceae
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Non-enteric
glucose fermenting Gram negative rods Oxidase + Motile with polar flagella MacConkey+ fresh water and salt water habitat |
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Vibrio cholerae
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undercooked seafood
epidemics--oral-fecal contamination of water somatic antigens 01 and 0139 |
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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 |
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Non-cholera Vibrios
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severe diarrheal symptoms, extraintestinal infections..some are invasive
wounds from infected marine water |
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Vibrio parahaemolyticus
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gastroenteritis in humas after eating contaminated seafood
mild to moderate, self-limiting extraintestinal infections from wounds rehydration only treatment required |
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Vibrio vulnificus
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very virulent. associated with wound infections
Septicemia and death reported after eating contaminated seafood 40-60% fatality rate invasive. hepatic disease makes more susceptible |
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Isolation of Vibrios
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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 |
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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 |
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Vibrio colony characteristics
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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 |
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Differentiation of Vibrios, Aeromonas, Plesiomonas and Chromobacterium
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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 |
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Treatment and prevention of non-cholera infections
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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 |
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Aeromonas
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Gram negative straight-not curved-rods
fresh and sometimes sea water coldblooded aquatic animals tap and distilled water wound infections, diarrheal disease, septicemia |
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Plesiomonas
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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 |
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Chromobacterium
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slightly curved, medium to long gram negative rods with rounded ends
C. violaceum bright purple pigment (interferes with oxidase test) |
