RAPID DIAGNOSIS OF CHOLERA CAUSED BY VIBRIO-CHOLERAE O139

Hybridomas secreting specific monoclonal antibodies (MAbs) to Vibrio c holerae serogroup O139 were produced. Sis monoclones (hybridomas) secr eting MAbs specific only to lipopolysaccharide of V. cholerae O139 str ains and which did not cross-react to 137 strains of other enteric mic roorganisms were obtained. These clones were designated 12F5-G11, 12F5 -G2, 15F5-H5, 5B9-F8, 14C9-D2, and 6D2-D8, The immunoglobulin (Ig) hea vy chain isotypes secreted by these clones were 1gG2b, IgG2b, IgG2b, I gM, IgG2b, and IgG3, respectively. Clone 12F5-G11 was selected for mas s production of MAb, which was used as a detection reagent in the anti gen detection assay for diagnosis of cholera caused by V. cholerae O13 9, and this assay was compared to the conventional bacterial isolation method. Five batches of rectal swab cultures in alkaline-peptone wate r were collected from 6,497 patients with watery diarrhea. These were 6,310 patients admitted to Bamrasnaradura Infectious Diseases Hospital , 16 patients from Krung Thon Hospital, 78 patients from Bangkok Child ren's Hospital, 19 patients from Karen refugee camps, and 74 Indian pa tients from the National Institute of Cholera and Enteric Diseases, Ca lcutta, India. The V. cholerae O139 isolations from the rectal swab cu ltures and the antigen detection assays (i.e., the MAb based dot-blot ELISA) were performed by different persons of different laboratories, and the results were revealed after all specimens had been tested. Of the 6,497 samples tested, the dot-blot ELISA correctly identified 42 o f 42 V. cholerae O139-positive samples and gave a result of positive f or three samples which were culture negative for V. cholerae O139, The diagnostic sensitivity, specificity, and efficacy of the dot-blot ELI SA were 100, 99.95, and 99.26%, respectively, The ELISA is easy to per form and relatively inexpensive, It can test multiple samples at a sin gle time, does not require special equipment, and does not produce gre at quantities of contaminated waste. Most of all, it reduces the diagn ostic time from at least 2 days for the bacterial isolation to less th an 90 min. The assay is recommended as a rapid screening test of chole ra cases caused by V. cholerae O139.