Enterotoxigenic Escherichia coli causing cholerogenic syndrome during an interepidemic period of cholera in North India

Abstract

A study was undertaken to look for heat-labile enterotoxin producing Escherichia coli (LT-ETEC) in patients with acute watery diarrhea resembling cholera in Chandigarh in North India. Two periods were selected, an interepidemic (2001) and an epidemic (2002) period. Heat-labile enterotoxin (LT) was detected using reverse passive latex agglutination test. LT-ETEC strains were serotyped and antimicrobial susceptibility was studied. LT-ETEC was detected in 16 of 21 stool samples during 2001. Other organisms isolated included Vibrio cholerae O1 Ogawa and Aeromonas hydrophila in 2 and 3 patients, respectively. During the epidemic period, 4 of 17 samples tested positive for LT-ETEC, whereas V. cholerae, Shigella, and Salmonella were isolated in 91, 2, and 1 patient, respectively. Similar features such as acute watery diarrhea and dehydration were common to patients examined in the interepidemic period and those examined during the cholera epidemic. The serotypes isolated were O15 (8), O63 (2), O148 (2), and O158 (2), and the remaining strains were untypable. More than 50% of patients were adults. Antimicrobial susceptibility was as follows: amoxycillin (3/20), nalidixic acid (6/20), trimethoprim (5/20), chloramphenicol (8/20), amikacin (19/20), gentamicin (13/20), cefotaxime (15/20), and ciprofloxacin (10/20). High fluoroquinolone resistance in ETEC may be a serious cause of concern for travelers visiting this region, and thus there is a need to monitor drug resistance in this pathogen.