Detection of Non-Typhoidal Salmonella Gastroenteritis in a Tertiary Children's Hospital in China

Background: Non-typhoidal Salmonella (NTS) especially the invasive NTS (iNTS) is associated with various gastrointestinal diseases with a significant increase in antibiotic resistance. Objectives: We determined the prevalence, antibiotic susceptibility of NTS and iNTS isolated from stool and blood samples of children aged 2 - 15 years, respectively. Methods: A total of 537 stool and 405 blood samples were collected from 613 children with symptomatic gastroenteritis between January 2016 and May 2018. Samples were subjected to microbiological analysis and antibiotic resistance was determined by the minimum inhibitory concentration (MIC) assay. beta-lactamase genes were detected by polymerase chain reaction (PCR). Results: A total of a total of 213 (39.7%) and 165 (40.7%) stool and blood samples grew Salmonella sp, respectively. Of these; 54 (10.1%) and 38 (9.4%) were identified as NTS and iNTS, respectively. Nalidixic acid (54.3%) resistance was the most the predominant resistance followed by ciprofloxacin (47.8%), cefotaxime (41.3%) and gentamicin (39.1%) among our isolates. The rate of resistance among iNTS was comparable and there was no significant (P > 0.05) difference observed in the resistance pattern between NTS and iNTS isolates. Among the resistant isolates, bla(CMY-2) gene (32.6%) was the most commonly detected gene. Conclusions: Overall, Salmonella typhimurium was the predominant species identified and bla(CMY-2) was the predominant gene amplified by our isolates. The high prevalence and increased resistance especially among iNTS is a cause of concern and reiterates the need to test blood samples along with the stool samples for better management of gastroenteritis.