Multidrug resistant Salmonella species harboring sulfonamide (sul1 and sul2) resistant gene isolated from typhoid patients in a university teaching hospital – A threat to public health

Abstract

This study aimed at characterizing multidrug resistant Salmonella species harboring sulfonamide ( sul1 and sul2 ) resistant gene that encode resistance to first line antibiotics used for the treatment of typhoid fever. The study examined two hundred and ten (210) stool samples from male and female patients attending Enugu State University Teaching Hospital, (ESUTH). Standard bacteriological techniques were used to screen for the presence of Salmonella enterica sub species. The antibiotics resistance pattern of the test isolates was determined using Kirby-Bauer disc diffusion method. Whereas the presence of antibiotic resistance genes were determined using primer specific 16S rRNA polymerase chain reaction (PCR) protocol. A total of 44 (20.95 %) Salmonella isolates were obtained, from both male (18 /26.47 %) and female (26 /19.70 %) with a significant difference (p<0.045). The test isolates from male patients displayed complete resistance to amoxicillin/clauvanic acid (100 %) and varied resistance to, trimethroprim-sulfamethoxazole (77.78 %), ampicillin (66.67 %), tetracycline (66.67 %) and chloramphenicol (61.11 %). While isolates from female patients displayed complete resistance to tetracycline (100 %) and varied resistance to amoxicillin/clauvanic acid (96.15%), chloramphenicol (84.62 %), ampicillin (84.62 %) and trimethoprim-sulfamethoxazole (61.54%). The study observed a mean multiple antibiotic resistant indexes (Mean MARI ± SD) of 0.72 ± 0.28ᵃ and 0.85 ± 0.18ᵇ in isolates from both male and female patients respectively. PCR analysis identified Salmonella specie strain KU641454, Salmonella enterica subsp. Enterica strain KY656604.1, Salmonella enterica subsp. Enterica serovar Heidelberg strain CP016579.1, Salmonella enterica subsp. Enterica serovar Chingola strain U92192 and Salmonella enterica subsp Enterica serovar Paratyphi B strain JQ694526 in the study. The study detected the presence of sul 1 and sul 2 resistance gene in Salmonella enterica subsp. Enterica strain KY656604.1 while other detected strains harboured only sul 2 gene. The presence and rapid spread of these resistance genes in bacteria pathogens are a concern in the nosocomial environment and if not properly monitored, they will constitute a threat in the treatment of bacterial infections.