Identification and Characterization of Major Causative Bacterial Agents of Diarrhea from Regions of Himachal Pradesh

Abstract

Diarrheal illness leads to an estimated 1.31 million deaths/annum among all age groups and mortality rates are quite higher (0.49 million deaths/annum) among children lt5 years. Disease burden is mainly concentrated in South East Asia particularly in India, where diarrhea incidences are quite higher as compared to other nations. Comprehensive surveillance studies exploring diarrhea incidences, their correlations with bacterial specific clinical parameters and antibiotic resistance are curbed in Himachal Pradesh. Therefore, present study was focused to investigate incidences of bacterial pathogens from an unexplored northern hilly state, Himachal Pradesh. newlineA total of 572 stool specimens were collected from diarrhea patients admitted to regional and tertiary care hospitals. From microbiological and biochemical characterization, diarrheagenic E. coli (DEC) was observed as major pathogen followed by Vibrio spp., Salmonella spp., and Shigella spp. Predominant pathogens; DEC and Vibrio spp. were further characterized using molecular approach. newlineIncidences of various DEC pathotypes were observed up to a level of 21%. DEC infection rates were quite higher in children lt5 years of age as compared to other age groups. Enteropathogenic E. coli (EPEC) was found as predominant molecular pathotype (13.7%) followed by enterotoxigenic E. coli (ETEC) (5.7%) and enteroaggregative E. coli (EAEC) (1.3%). Serogrouping of DEC pathotypes showed circulation of somatic antigens O26, O2 and O3 as major serogroup among EPEC, ETEC and EAEC pathotypes, respectively. DEC pathotypes exhibited alarming resistance against all tested antibiotics. newlineBiochemical and molecular characterization of Vibrio spp. showed incidences up to a level of 4.7%. Highest incidences of Vibrio spp. were observed among adolescents and adults than other age groups. Vibrio spp. exhibited higher levels of resistance against cephalosporins and nalidixic acid but showed susceptibility for carbapenems, aminoglycosides and quinolones classes of antibiotics. newline