Antibiotic Susceptibility Testing (AST) Reports: A Basis for Environmental/Epidemiological Surveillance and Infection Control Amongst Environmental Vibrio cholerae

Distribution, investigation, surveillance and control (DISC) of cholera outbreaks in endemic/non-endemic regions has been a concerted approach towards the management of the causal pathogen. Relevant organization, government, health systems and the public have implemented several steps towards controlling the menace, yet pathogen continues to occur with diverse phenotypes/genotypes of high clinical and epidemiological relevance. The study determines antibiotic susceptibility/resistance pattern of Vibrio cholerae isolates retrieved from six domestic water sources between March and August 2018. Serological and molecular typing methods (polymerase chain reaction or PCR) were used to confirm the isolates identity. Antibiotic susceptibility testing was conducted using six commonly employed antibiotics of V. cholerae according to the recommendation of Clinical Laboratory Standard and European Committee for Antimicrobial Susceptibility Testing with other relevant antibiotics of investigative epidemiology and infection control, employing both disc diffusion test and PCR gene detection. Samples presumptive counts ranged between 1.10 to 7.91 log10 CFU/mL. Amongst the 759 presumptive isolates retrieved, sixty-one were confirmed as V. cholerae which were further serogrouped as Non-O1/Non-O139 V. cholerae . Various V. cholerae resistant phenotypes/genoytypes were detected vis: carbapenemase (CR-Vc; 31.1%/5.3%). New Delhi Metallobetalactamase (NDM-1-Vc; 23.0%/42.5%), extended spectrum betalactamase (ESBL-Vc; 42.6%/blaTEM:86,7%), chloramphenicol resistance (62.3%/Flor: 46.2%}, tetracycline resistance (70.5%/46.7%), AmpC resistance (21.0 (34.4%/56.7%)) and various other resistant genotypes/phenotypes. It was observed that more than 50% of the confirmed V. cholerae isolates possess resistance to two or more antibiotic classes/groups with multiple antibiotic resistance index (MARI) ranging from 0.031 to 0.5. This observation provides necessary information and updates for surveillance, planning and implementation of control strategies for cholera. It would also encourage decision making, formulation of policy by the government and cholera control authorities.