Unusual GNR Fermenters Flashcards
inflammation of the stomach and intestines, resulting from bacterial toxins or viral infection and causing vomiting and diarrhea
gatroenteritis
Genera that are considered unusual fermenters
Vibrio, Aeromonas, Plesiomonas, Campylobacter
infection of the intestines resulting in severe diarrhea with the presence of blood and mucous in the feces
dysentery
Stool specimen collection requirements
stool or rectal swab has a two hour window if placed in a sterile cup
Stool specimen preservatives
Cary Blair, Buffered Glycerol Saline, Alkaline Peptone Water, Modified Stuart’s
Oxidase positive, fermenters of glucose, isolated in coastal areas (fresh, brackish, and salt water), associated with seafood consumption
Vibrio Species characteristics
Describe vibrio morphology
Curved or comma shaped GNRs, polar flagella, halophilic (require Na)
caused by Vibrio, spread by fecal-oral route, severity variable but usualy severe diarrhea, death results from massive fluid loss/shock/acidosis
Cholera
notorious pathogen, no tissue invasion, enterotoxin production (adheres to small intestine), “rice water stools”
Vibrio cholera
Treatment of cholera
fluid/electrolyte replacement; tetracycline in severe cases
collection/transport requirements for stool/wounds (cholera)
stool: susceptible to desiccation, within first 24 hrs of infection, cary-blair at room temp (no buffered glycerol saline transport); wounds: sterile swabs
What do we use to isolate cholera?
Thiosulfate Citrate Bile Salts Sucrose Agar (TCBS Agar), SBA, MAC
Describe TCBS agar
green plate; selective and differential; sucrose fermenters (yellow colonies)/non-sucrose fermenters (green colonies)
Hemolysis present on SBA from cholera
Beta
MAC Results in cholera
Most Lactose Negative
Inubation requirements for cholera
Ambient air at 35’C
What methods can we use to identify cholera?
string test, vibrostatic test, KIA and Phase II, automation, MALDI-TOF, O1 or O139 antisera in coastal areas
list 3 non-cholera vibrios
V. parahaemolyticus, V. vulnificus, V. alginolyticus
Endemic to Japan, mild gastroenteritis (ingestion of raw fish), wound infections (contaminated seawater), Kanagawa Phenomenon, does not ferment sucrose
V. parahaemolyticus
more wound infections than diarrhea (contaminated seawater), septicemia, invasive, liver disease, non-sucrose fermenting
V. vulnificus
wound infections, infections of ears and eyes, infrequently isolated in clinical laboratory, ferments sucrose
V. alginolyticus
straight/coccobacillary GNR, polar flagellum, inhabitants of aquatic ecosystems (fresh and brackish water); obtained from fresh produce, meat, and dairy products or exposure to aquatic source
Aeromonas spp
cause gastroenteritis (mild watery, self limiting diarrhea, spring to fall seasons) and extraintestinal infections
Aeromonas spp
specimen collection and transport for aeromonas spp
stool: Cary-Blair or buffered glycerol saline as transport; process within 2 hours
wounds: sterile swabs