Mohan kumar yadav

B.Sc-M.Sc Bioinformatics

JNU,Jaipur

Vibrio cholerae is a usual inhabitant of the marine environment

causes severe diarrheal disease contaminating thousands of people each year in developing countries.

Cholera is still a threat to a large number of people in the universe.

Gram-negativeHighly motile; polar flagellum Brackish rivers, coastal waters

Associate with plankton and algaeProliferate in summers Cholera toxinPathogenic and nonpathogenic

strains206 serogroups

Grows in salt and fresh water Can survive and multiply in brackish

water by infecting copepods Has over 150 identified serotypes

based on O-antigen Only O1 and O139 are toxigenic and

cause Cholera disease 2 categories of O1 serotypes –

Classical and El Tor

A life-threatening secretory diarrhea induced by enterotoxin secreted by V. cholerae

food contaminated by copepods infected by V. cholerae

An enterotoxic enteropathy (a non-invasive diarrheal disease)

A major epidemic disease

Occur 2-3 days after consumption of contaminated food/water

Usually mild, or no symptoms at all 75% asymptomatic 20% mild disease 2-5% severe

Vomiting Cramps Watery diarrhea (1L/hour) Without treatment, death in 18

hours-several days

One hundred water samples were collected from four stations of Ahvaz Karun River.

After DNA extraction, a polymeras chian reaction (PCR) assay was performed for detection of ctxA and tcpA (both Classical and ElTor variants) and OmpW was in the strain that was recognized as V. cholerae non - O139 and non - O1

The virulence of Vibrio spp. is regulated by the ctxAB and tcpA genes.

These genes are supposed to be exclusively associated with clinical strains of O1 and O139 serogroups

Among 100 environmental samples of fresh water in this study, 27 isolate confirmed as V. cholerae spp. by PCR assay with ompW gene.

4 isolate that were confirmed V. cholerae non O1- non O139 had gene for toxin coregulated pilli.

2 main serogroups carry set of virulence genes necessary for pathogenesis

O1Classical: 1 case per 30-100 infections

El Tor: 1 case per 2-4 infections O139

Contained in India, Bangladesh

V. cholerae is one of the major causes of morbidity and mortality in the developing countries.

The studies that were performed on V. cholera nonO1, nonO139 strains that usually do not carry the ctx genes coding for cholera toxin (CT) or toxin-co regulated pilus which are the most important virulence characteristics of the cholera causing strains.

Pathogenic strains of V. cholerae contains two essential genetic elements, CTX element and the vibrio pathogenicity island (VPI) and toxin co-regulated pilus (TCP), respectively (Mishra et al., 2011)

tcp gene

ctx gene

It is believed that most of the environmental strains do not produce cholera toxin

The knack of pathogenic Vibrio spp. to cause disease depends on the expression of virulence factors like a potent enterotoxin (CT), a pilus colonization factor toxin co-regulated pilus; TCP).

Cholera toxin (CT), which is responsible for the life threatening diarrheal disease cholera gravis caused by epidemic cholera (Blackstone et al., 2007). All Vibrio strains that are able of causing cholera continuously carry genes for TCP

The nucleotide sequencing of OmpW gene in V. cholerae strains has unchanged among different V. cholerae strains that has made it a highly proper genetic marker for the organism (Nandy et al., 2000).

Gene Primer Oligonucleotide Amplicon size

1.CtxA *F 5-CTCAGACGGGATTTGTTAGGCACG-3 301-bp References –(Shirai et al. (1991)).

*R 5-TCTATCTCTGTAGCCCCTATTACG-3

tcpA *F 5-CACGATAAGAAAACCGGTCAAGAG-3 617-bp

*R 5-ACCAAATGCAACGCCGAATGGAGC-3 tcpA *F 5-GAAGAAGTTTGTAAAAGAAGAACAC-3 471-bp *R 5-GAAAGGACCTTCTTTCACGTTG-3 OmpW- *F 5-CACCAAGAAGGTGACTTTATTGTG-3 588 bp *R 5-GAACTTATAACCACCCGCG-3

In this investigation, we have studied the probability of the presence of genes that cods tcpA and ctxAB in V. cholerae non O1 and non O139.

Boil or treat water with chlorine or iodine Cook everything Wash hands frequently

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Identification of Vibrio cholerae pathogenicity island (ctxA, OmpW and tcpA) in non - O139 and non - O1 V. cholerae strains isolated from Karun River in

Ahvaz, Iran Ahmad Farajzadeh Sheikh1,2, Hamed Goodarzi1* and Sajad Aslani1