Vibro, Pleo, Aero, Campy Flashcards
Vibrio Spp. similarities in habitat
Aquatic enviroments, fresh water, brackish, marine or alt water
Halophilic (except Vcholerae and V mimicu)
Tolerate alk enviro(toxic to other orgs)
Vibrio Spp. general Characteristics
GNR Polar sheathed flagella (in broth), peritrichous unsheathed (on solid media) Rods are curved in clinical specimens but straight rods after culture Facultatively anaerobic have O and H ag(allow serotyping) most are oxidase pos Nitrate pos all sus to O/129 Ferm glucose string with sod desoxycholate
Hints to Vibrio Infection
Recent consumption of raw seafood (especially oysters)
Recent immigration or foreign travel
Accidental trauma during contact with fresh or marine water
Predisposing factors–> liver problems (alcoholic), malignancies, diabetes
Vibrio cholerae
Environment Salt water and freshwater Warm season and poor sanitation Undercooked seafood Microscopic morphology Comma shaped gram negative rods Shooting star motility in fresh stool O1 or O139 causative agents of cholera “Rice Water” stools**** Colorless or gray fluid with flecks of mucus Caused by cholera toxin or choleragen(hypersecrete electrolytes),metabolic acidosis, shock, circ failure Loss of electrolytes & water Dehydration is usual cause of death Man is the only host
Special considerations and media for Vibrio cholerae
Specimen collection and transportation
Cary-Blair medium
Alkaline peptone water
Media for isolation
Routine
Thiosulfate citrate bile salts sucrose (TCBS) agar
BAPmed to large, alpha to beta hemo, yellow to greenish hue, NLF on Mac
OXIDASE pos must diff from enterics
TCBSvibro ability to ferment sucrose, 1% NaCl to help grow, change from blue grren to yellow with ferm
Vibrio cholerae Identification
Routine media SBA Medium-large colonies; smooth, opaque, irredescent with a greenish hue; might see α or β- hemolysis MAC NLF Selective/Differential Media TCBS (Thiosulfate citrate bile salts sucrose) agar Yellow colonies indicate acid production Positive result for V. cholerae Susceptibility to O/129 10 µg – susceptible 150 µg - susceptible String Test: 7mm
Serogroup O1 El Tor
Hemolyze RBC, Beta hemolysis
Vibrio parahemolyticus Characteristics
“Summer diarrhea” in Japan
Gastroenteritis
Most cases traced to recent consumption of raw, improperly cooked, seafood, especially oysters….they like warm ocean water
Gastrointestinal symptoms are generally self-limiting; watery diarrhea, moderate cramps or vomiting
Skin infections associated with salt water exposure(occasionally)
Vibrio parahaemolyticus Identification
Microscopic morphology: straight or curved gram negative rods Halophilic Nonfermenters of lactose Oxidase + Indole + Colonies are GREEN on TCBS agar String test: shorter than 3 mm Susceptibility to O/129 10 µg – resistant 150 µg – susceptible
Vibrio vulnificus characteristics
Found in marine environments along all coasts in the U.S.
Two categories of infections
Primary septicemia following consumption of contaminated shellfish, especially raw oysters; patients with liver dysfunction that results in increased levels of iron are predisposed
Wound infections following traumatic aquatic wound(fishing)
Vibrio vulnificus Identification
MacConkey agar Ferments lactose TCBS agar Non-sucrose fermenter Appears as clear, blue-green Oxidase + Lactose fermenter** grows better with addition of 1% NaCl
Aeromonas hydrophila Characteristics
Environment
Fresh and salt water
Leeches
Cold blooded animals
Microscopic morphology: straight or curved gram negative rods
Aeromonas species are ubiquitous and are readily recovered from water, including tap water in hospitals and carbonated mineral water They have been identified in the mucus trails of leeches , where they are the main or even the only bacteria present
Aeromonas hydrophila Infections
Gastroenteritis
Usually results from consumption of contaminated seafood, especially raw oysters or clams; illness usually self-limiting, except in very young and old populations
Wound infections
Resulting from traumatic water-related wound
Septicemia
Targets immunocompromised
Summer months inc risk of infection
Aeromonas hydrophila: Laboratory Diagnosis
SBA
large, round, raised, opaque colonies, often mucoid, can be translucent- white; Beta-hemolytic
MAC
Most do NOT ferment Lactose, but some strains can
CIN (cefulodin, irgasan, novobiocin)
pink-centered colony
Oxidase + AND Indole +
Differentiate from VIBRIO by NEGATIVE ornithine decarboxylase reaction, NO growth on TCBS or 6.0% NaCl, and resistance to O/129
Can look like Yersinia
Plesiomonas Characteristics
Found in soil and aquatic environments; particularly fish and estuarine waters of tropical and subtropical climates
Warm and cold blooded animals are carriers
Occupational exposure is the source of some infections;(fish handlers, vets, zookeepers)
