Vibrio
The organism gram -ve, these organism are most commonly found in water bodies.
Both fresh water and marine water environment.
Rid shaped, curved shaped, highly motile, they possess O and H antigen.
Most important member of genus is vibrio cholerae.
Vibrio cholerae causes cholera in human.
Human pathogenic members of vibrio are;
1. Vibrio cholerae serogroup 01 strain.
2. Non- 01 vibrio cholerae strain
3. Non agglutinating vibrio (NAV)
4. Vibrio parahaemolyticus
1. Vibrio cholerae
It causes cholera disease in human beings.
Morphology
Gram -ve, curved or comma shaped, rod, non sporing, non capsulated.
Size; about 1.5 micrometre X 0.2- 0.4 micrometre in size.
Highly motile
Characteristics
Strongly aerobic.
Grow with temperature range of 16-40 degree celcius.
Best in alkaline media, optimum PH 8.2
Sources and mode of Transmission
Vibrio cholerae transmitted by;
1. Contaminated water and food.
2. Row or uncooked sea food from contaminated water.
Pathogenesis
Vibrio cholerae causes acute diarrhoeal disease known as cholera and it occurs only in man.
Human infection occurs by ingestion of contaminated food and drink.
Vibrio cholerae pass through acid barrier of stomach and multiply in alkaline medium of small intestine.
Cause vomiting, watery stool, rectal swab.
Vibrio cholerae produce Enterotoxin (Cholera toxins).
Laboratory Diagnosis
Specimen collection and transport proper
Watery stool, rectal swab
Strip of blotting paper
Hanging drop method
Gram stain
Culture characteristics and culture
Biochemical test
Ferments glucose, sucrose, maltose and mannitol.
Treatment
Oral rehydration therapy
Water and electrolytes
Intravenous therapy
Antibiotics; tetracycline is useful in reducing number of stool.
Prevention
Purification of water supplies.
Better provision of sewage disposal.
Infected patient should be isolated, their excreta disinfected.
Intake hygienic food.
Non Cholera Vibrios, NAV, Vibrio Parahaemolyticus
All organisms have ability to grow in high concentration of NaCl. So they are common in costal sea water.
Vibrio Parahaemolyticus is associated with gastroentestinal illness.
Non Cholera Vibrios and NAV are associated with soft tissue infection and septicemia.
Treatment
Administration of antibiotics such as tetracycline or cefotaxime are effective.
In severe case surgical drainage may required.
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