Epidemiological Analysis of Salmonella Enterica Serovar Typhimurium and Serovar 1,4,[5],12:i:- Isolates Determined by Pulsed Field Gel Electrophoresis and Antibiotic Susceptibility: Comparison of Isolates from Broiler Chickens, Humans and the Environment in Reunion Island

摘要

Salmonella enterica ssp. enterica is a leading cause of bacterial food-borne disease outbreaks worldwide and isalso an economic burden particularly in Reunion Island because its population consumes large amounts of chicken andcooks 100% chicken sausages (35 kg per capita per year).The aim of this study was to investigate the epidemiology of Salmonella Typhimurium and Salmonella 1,4,[5],12:i:- frombroiler chickens, humans and the environment by using pulsed field gel electrophoresis (PFGE) and antibioticsusceptibility and to assess the significance of broiler chicken meat as a source of human infection.A total of 157 Salmonella Typhimurium and 19 S. I 4,[5],12:i:- were collected and isolated from broiler chickens, humansand the environment between October 2007 and January 2009. The PFGE of Xba1 digested chromosomal DNA gave 30distinct profiles for Salmonella Typhimurium and S. 1,4,[5],12:i:-. Salmonella Typhimurium was characterized by a mainpulsotype (B54) and accounted for 32% of all isolates. This pulsotype included isolates from many sources such as broilerchickens, poultry houses, slaughterhouses, other animal species (ducks, pigs and rodents) and humans, suggesting that ithad already colonized every step of the food chain. Antibiotic susceptibility tests showed that most isolates were resistantto ampicillin, streptomycin, sulfonamides and tetracycline.The similarity of PFGE profiles of isolates from various sources and particularly from poultry and humans underlinedpossible transmission of Salmonella from contaminated broiler meat, but most of the isolates remained drug-sensitive.Significance and impact of study: Efforts are needed to eliminate Salmonella from poultry meat destined for humanconsumption. This study has also shown the importance of monitoring antimicrobial resistance in bacteria associated withanimals and humans.