Salmonella and Shigella caused infectious diarrhea in children and pathogens drug resistance in Hangzhou, Zhejiang, 2008-2012

Objective To understand the epidemiological and etiological characteristics of infectious diarrhea caused by Salmonella and Shigella in children and pathogens drug resistance in Hangzhou, Zhejiang province and provide evidence for the related research and rational use of antibiotics. Methods Salmonella and Shigella were cultured by using the stool samples collected from the diarrheal children hospitalized or seeking medical care in our hospital. The isolated strains were identified by biochemical and serological tests, and disk diffusion method was used to test the drug susceptibility of these strains. Results A total of 281 pathogenic strains were isolated from 2008 to 2012, including 119 Shigella strains (42.3%) and 162 Salmonella strains (57.6%). In 119 Shigella strains, 82 were S. flexneristrains (29.2%),31 were S. sonnei strains (11.0%) and 6 were S. boydii strains (2.1%). S. flexneriand S. sonnei strains were predominated with the ratio of 2.64:1. No S. dysenteriae was detected. The proportion of Salmonella strains detected increased year by year. The male to female ratio of the cases was 1.38:1. Infectious diarrhea mainly occurred from May to October, but the incidence peak was during July-August. The drug resistance of Shigella and Salmonella were different. The drug resistant rate of Shigella was higher than that of Salmonella. The results of drug susceptibility test in vitro showed the resistant rates of Shigella and Salmonella to cefotaxime, ceftriaxone, ampicillin/sulbactam and SMZ-TMP were higher than those to ceftazidime, ampicillin, cefepime, cefoperazone/sulbactam and piperacillin/tazobactam. No resistance to imipenem was detected. Conclusion In recent years, the incidence of diarrhea caused by Salmonella in children increased in Hangzhou. S. flexneri was also the major pathogen to cause bacteria diarrhea in children. Piperacillin/tazobactam, ceftazidime and cefepime. are usually used to treat infectious diarrhea caused by Shigella and Salmonella in children.