Changing Susceptibility Pattern of Vibrio cholerae O1 Isolates to Commonly Used Antibiotics in the Largest Diarrheal Disease Hospital in Bangladesh during 2000–2018

The efficacy of commonly used antibiotics for treating severe cholera has been compromised over time because of the reduced antibiotic susceptibility. This study aimed to describe the rate of detection of Vibrio cholerae O1 from fecal samples and antimicrobial susceptibility profiles of V. cholerae O1 serotypes to commonly used antibiotics. During January 2000-December 2018, V. cholerae O1 was detected in fecal samples of 7,472 patients. Vibrio cholerae O1 Inaba serotype was predominant, ranging from 60% to 86% during the period 2000-2006 except for 2003 and 2005 when the Ogawa serotype was predominant. Later on, the Ogawa serotype became predominant from 2007 to 2015, fluctuating between 52% and 100%. However, in 2016 and 2017, isolation rates declined to 2% and 1%, respectively, but surged again to 75% in 2018. Nearly 100% of V. cholerae O1 strains were sensitive to tetracycline during 2000-2004. Thereafter, a declining trend of sensitivity was observed to be continued and dropped down to < 6% during 2012-2017 and again increased to 76% in 2018. Susceptibility to azithromycin and ciprofloxacin was nearly 100%, and susceptibility to cotrimoxazole and furazolidone was 01% throughout the study period. We also found the emergence of resistance to erythromycin in 2005 and sensitivity to cotrimoxazole in 2018. Thus, the rapid decline of the sensitivity of V. cholerae O1 to tetracycline and a reversed peak after 6 years need continued monitoring and reporting.