Molecular subtyping and antibiotic resistance of non-Typhi salmonella isolated from infants

Objective To investigate the molecular characteristics and antibiotic resistance of non-Typhi salmonella isolated from infants. Methods Stool samples were collected from infants with diarrhea in Shanghai to isolate non-Typhi salmonella. The isolated strains' identification, serotyping, molecular subtyping and drug susceptibility test were conducted Results A total of 19 non-Typhi salmonella strains were isolated from 583 infant stool samples, and the majority were Salmonella enterititis and Salmonella typhimurium strains. The PFGE patterns of Salmonella enterititis strains were similar (88.7%), and were the prevalent patterns of the strains isolated in Shanghai in recent years. The drug susceptibility test showed the antibiotic resistance rate of the strains in this study was 78.95% (15/19). The resistance rates to Nalidixic acid (68.42%), Ampicillin (63.20%), and the third generation Cephalosporins (40%) were higher than those to other antibiotics, and the resistance rates to Ciprofloxacin (10.53%) and Gentamicin (10.53%) were low. In addition, most strains (13) were multidrug resistant. Conclusion The antibiotic resistance of the non-Typhi salmonella isolated from infants with diarrhea was serious, and the differences in drug resistance among the strains with different serotypes and molecular types had no statistical significance.