19 - Vibrio

major species

V. cholerae
V. parahaemolyticus
V. vulnificus

gram stain / morphology

gram neg, curved rods

motility

monotrichous

unique characteristics

tolerates high pH. susceptible to low pH
O antigen

V. parahaemolyticus, V. vulnuficus
- transmission
- clinical manifestation
- treatment

- raw fish --> gastroenteritis (common in Japan/SE Asia)
- wound infections, septicemia --> Doxycycline + Cephalosporin
- tissue necrosis, necrotizing fasciitis

V. vulnuficus --> gasteroenteritis --> septicemia

V. parahaemolyticus, V. vulnuficus - when do infections occur

summer
- seafood contamination
- water contamination doing water activities

V. cholerae - discovery

1884 R Koch
1854 J Snow made connection bw cholera outbreaks and water quality

V. cholerae - serotypes assoc w outbreaks

O1 and O139

O1 has no K antigen

V. cholerae - how many epidemics since what year?
what serotype caused them
where do outbreaks occur
principal cause of outbreaks

7 major epidemics since 1816
caused by serotype O1
occur in underdeveloped countries
principal cause - lack of access to safe water

V. cholerae - where is it found

bacteria multiply in water, high bac in feces of infected/recovering patients

V. cholerae - transmission

consumption of contaminated water
in US - returning travelers/consumption of contaminated seafood

V. cholerae - infectious dose

high, 10^6-10^8

V. cholerae - clinical manifestations (what serotypes)

cholera (O1 and O139)
gastroenteritis

cholera - symptoms

abrupt onset (2-3 days)
watery diarrhea, vomiting
"rice water" stools - colorless/odorless, speckled w mucus (high bac)
up to 1L fluid loss hourly
dehydration, cardiac/renal failure
60% mortality untreated

gastroenteritis symptoms, caused by what V. cholerae serotypes

mild diarrhea, self limiting
non cholera toxin serotypes

V. cholerae pathogenesis - factors and what do they do

cholera toxin --> loss of water/electrolytes
toxin co-regulated pilus --> adhesin
colonization factor --> adhesin
toxins that inc intestinal fluid secretion
ToxR regulator?

V. cholerae diagnosis

McConkey - non lactose fermenter
TCBS
PCR based detection of toxin gene
O antigen

what is TCBS

thiosulfate citrate bile salts sucrose
- sulfate/citrate inhibit Entero
- bile salts inhibit gram pos

V. cholerae treatment

replacement of fluids/salts - rehydration (ORS), drink as much as you lose
sometime IV fluid replacement
antibiotics to shorten course/reduce severity
- Doxycycline for adults
- TMS for children

what is ORS

oral replacement salts
treatment for V. cholerae

V. cholerae prevention

sanitation
food safety
oral vaccine recommended during outbreaks

2 cholera vaccines, purpose and why its given

Dukoral, ShanChol
offers short term protection
during outbreaks to limit transmission

what is Dukoral

choler vaccine
based on heat killed bacteria (O1) and cholera toxin B subunit

what is ShanChol

cholera vaccine
based on heat inactivated bacteria (O1 and O139)