Vibrios, Campylobacters and Associated BacteriaGeneral Characteristics: Gram-negative rods Widely distributed in nature

Vibrio choleraeGeneral CharacteristicsCurved rods/ Comma-shapedAerobicGrow at very high pHMotile with polar flagellumNo spores

Vibrio cholerae

Vibrio choleraeClinical FindingsCholeraIncubation period: 1-4 daysS/S; nausea, vomiting, abdominal cramps, "rice water" stool (contains mucus, epithelial cells and large volume of vibrios), rapid fluid and electrolyte loss

Vibrio choleraePathologyEnterotoxin- causes hypersecretion of water and electrolytesAttach to the microvilliPathogenic only to humansNon-invasive

Vibrio choleraeBasis of classification: O antigenV. cholerae strain O group 1 - causes classical choleraSerotypes: Ogawa, Inaba, El Tor V. cholerae non-O1 - causes cholera-like disease *El Tor biotype cause milder diarrhea than the classic types

Vibrio choleraeDiagnostic Laboratory TestsDark-field or phase-contrast microscopyPeptone or TCBS (Thiosulfate Citrate Bile salts Sucrose) agar

TreatmentFluid and electrolyte replacement Tetracycline

Vibrio choleraeEpidemiology, Prevention and Control

Mortality rate with treatment is 25-50% Worldwide epidemics: 1960 - classical biotype1905 - El Tor biotype was discovered 1960 - pandemic in Asia, Middle East, and Africa

Vibrio cholerae

Endemic in India and Southeast AsiaTransmission: person-to-person contact (water, food, flies)Carrier state: 3-4 weeks

Vibrio parahaemolyticusHalophilic Causes acute gastroenteritisTransmission: ingestion of contaminated seafoodIncubation period: 12-24 hrsS/S: nausea, vomiting, abdominal cramps, fever, watery to bloody diarrheaThe disease subsides after 1-4 days with no treatment other than restoration of water and electrolytesOccurs worldwide

Vibrio parahaemolyticusTCBS Agar

Vibrio vulnificus

HalophilicCan cause skin lesions, enteritis, bacteremia

Camylobacter jejuni

General CharacteristicsGram-negative rods with comma, S or "gull-wing" shapes Motile with single polar flagellumDo not form spores

Camylobacter jejuni

Camylobacter jejuniClinical FindingsCampylobacter enteritisS/S: crampy abdominal pain, profuse diarrhea with blood, headache, malaise, and feverIllness is self-limited to 5-8 days

Camylobacter jejuniPathogenesisVirulence factor: lipopolysaccharide with endotoxic activityInvade the epithelium and produce inflammation that results in the appearance of RBC and WBC in stools

Helicobacter pyloriPreviously known as Campylobacter pyloriSpiral-shaped, gram-negative rodMotile Strong producer of ureaseGrow at pH 6.0-7.0

Helicobacter pyloriIt is present in the gastric mucosa of less than 20% of persons under age of 30 but increase in prevalence in elderlyMode of transmission: person-to-personCauses gastritis and appears to be important in the pathogenesis of duodenal (peptic) ulcerH. pylori modifies the gastric mucus and further reduces the ability of acid to diffuse through the mucus

Camylobacter jejuniDiagnostic Laboratory TestMicroscopy: dark-field or phase-contrastCulture: Skirrow's and Campy BAP mediumEpidemiology and ControlMode of transmission: oral route from food (milk), drink, contact with infected animals, sexual activities