Prevalence of Salmonella and Shigella spp. and antibiotic resistance status in acute childhood gastroenteritis

Abstract

Objective: Acute gastroenteritis is an important cause of morbidity and mortality in developing countries. Children under 5 years of age are more commonly affected, while 80% of deaths occur in children under 2 years of age. Escherichia coli, Salmonella spp., and Shigella spp. are the most common causative bacterial pathogens. Since the summer of 2014, a large number of Salmonella and Shigella gastroenteritis cases have occurred in our region, which is considered as a small local outbreak. We aim to report the features and antibiotic susceptibility of microorganism isolates obtained during this epidemic. Material and Methods: Between July and September 2014, patients who were admitted to pediatric clinics and emergency services on account of acute gastroenteritis lasted less than 15 days were included in this retrospective study. Stool microscopy, stool cultures, and blood cultures were performed. Salmonella and Shigella strains were subjected to antimicrobial susceptibility testing. Results: A total of 2425 patients were admitted because of acute gastroenteritis during the study period. Salmonella spp. and Shigella spp. were isolated in 113 children. The mean age of the children was 91.5±60.3 months (4-213 months). Of the 113 patients, 56% were male and 44% were female. Shigella spp. were found in 77 patients (3.2%), and Salmonella spp. were found in 36 patients (1.5%). Salmonella enteritidis was detected in 29 patients (80.5%), whereas Salmonella typhimurium was detected in 3 patients (8.3%). In addition, Shigella sonnei was identified in 63 patients (81.8%) and Shigella flexneri in 8 patients (10.3%). In contrast to ceftriaxone susceptibility in Salmonella strains, 9.1% of Shigella strains were found to be resistant to ceftriaxone. Ciprofloxacin resistancewas found in 5.6% and 1.3% strains of Salmonella and Shigella spp. respectively. Although the ampicillin resistance values of 2 strains were close, trimethoprim-sulfamethoxazole (TMP) resistance was found in 89.6% Shigella strains. Conclusion: Salmonella and Shigella are common bacterial pathogens. Resistance patterns must be known to select the most effective treatment. According to our study, ceftriaxone and ciprofloxacin appear to be the first choice of empirical treatment for acute bacterial gastroenteritis. Additionally, if the resistance states of ampicillin and TMP are known, these drugs can also be used as empirical treatment.