NON ENTERIC GASTROINTESTINAL PATHOGEN Flashcards
Comma/curved bacillus
Vibrio
It is found in brackish or estuarine water, and marine water or salt water. It is temperature sensitive (> 20°C) and it can be isolated from algae, plankton, fish and shellfish.
Vibrio
Facultative anaerobe, monotrichous, halophillic organism (halophilic except V. cholerae and R. mimicus)
Vibrio
Vibrio spp. are halophilic except…
V. cholerae and R. mimicus
Microscopic appearance of Vibrio
Gram negative short, curved rod
Asporogenous
Susceptibility test for Vibrio spp.
150ug VIbriostatic disk on MHA or TSA (01/29)
Virbio mode of acquisition
Consumption of raw or undercooked seafoods
Diseases /Infection associated with Vibrio
Cholera, wound infection, septicemia and necrotizing fasciitis
Smooth, opaque, Iridescent with a greenish hue (CAP)
a or ß hemolysis (BAP)
Oxidase (+)
Reduce nitrates to nitrite
Glucose fermenter, NLF
Motility test: polar sheated flagella (broth)
Peritrichous, unsheated flagella (solid media)
Vibrio
Reduce nitrates to nitrite except V. metschnikovii
Glucose fermenter, NLF except V. vulnificus
Vibrio spp. that causes the most severe disease
V. vulnificus
The causative agent of cholera/asiatic cholera/epidemic cholera
V. cholerae 01
The single flagellum Is covered with lipopolysaccharide sheath. It has rapid darting or shooting-star motility.
Vibrio cholerae
Vibrio cholerae has caused Cholera epidemic (_____strains) and seven pandemics (______ strains)
01 and 0139 strains
01 strains
Epidemic V. cholerae 01 biogroups
Classical
El tor
VP (-); do not agglutinate chicken RBC, susceptible to polymixin B (50kg)
Classical V. cholerae 01
VP (+); agglutinate chicken RBC; resistant to polymixin B (50/g).
El tor V. cholerae 01
Vibrio cholerae potent enterotoxins
Cholera toxin (CT)
Zot toxin
Ace toxin
Vibrio cholerae virulence factor
Choleragen
String test reaction of Vibrio cholerae
Mucoid “stringing” reaction
Vibrio cholerae antigenic structures
Somatic O and Flagellar H (V. cholerae subgroups)
Virbio cholerae TSI reaction
A/A, (-) gas, (-) H2S
Mode of acquisition of Cholera
Mainly through contaminated water
Ingestion of improperly preserved food like seafoods (shellfish), milk and ice cream
It is an acute diarrheal disease with rice-watery stool (10-30x of defecation/day)
Cholera
2 functional units of choleragen
Enzymatic A subunit
Intestinal receptor-binding B subunit
How does choleragen stimulate diarrhea?
A subunit choleragen enters the intestinal epithelial cells and activates the enzyme adenylate cyclase by the addition of an ADP-ribosyl group in a way similar to that employed by diptheria toxin
Responsible for the stimulation of hypersecretion of water and chloride ions while Inhibiting absorption of sodium ions, leading to massive fluld loss (10-15 liters) and electrolytes
Choleragen
____ provides the attachment to mucosal cells for cholera toxin release
Toxin-coregulated pili (TCP)
Allows for the penetration of the mucosal layers
Mucinase
The second most common Vibrio species Implicated in gastroenteritis
Vibrio parahaemolyticus
It is the etlologic agent of “summer diarrhea” in Japan
Vibrio parahaemolyticus
Vibrio parahaemolyticus pandemic strain
V. parahaemolyticus serotype Us:K6
Vibrio parahaemolyticus mode of acquisition
Eating contaminated seafoods like oyster, scallops, crabs, lobsters and shrimps, and even sardines
Vibrio parahaemolyticus virulence factor
Heat-stable hemolysin
The phenomenon wherein hemolysis is induced by hemolysins
Kanagawa phenomenon
Bacteria associated with kanagawa phenomenon
Vibrio parahaemolyticus
Selective medium for Vibrio parahaemolyticus
Wagatsuma agar (high-salt mannitol medium)
Strains of Virbio parahaemolyticus that can lyse human RBCs is known as…
Konagawa toxin positive.
It was commonly referred to as the “lactose-positive” Vibrio
Vibrio vulnificus
Second to V. cholerae in terms in producing serious type of Vibrio-associated infection
Vibrio vulnificus