Objective: To understand the infection of Salmonella (S.) in patients with diarrhea and outbreaks caused by Salmonella to identify the serotypes, resistance to antibiotics and PFGE types of the strains from the surveillance program in Guangdong province.
Methods: S. strains from patients with diarrhea were detected, and all the positive strains collected in routine and outbreak surveillance programs, were tested by serum agglutination, antibiotic susceptibility and PFGE.
Results: 71 S. strains were isolated from 1922 stool samples in 2008, with positive rate as 3.7%. 85 S. strains were isolated from 2110 stool samples in 2009, with positive rate as 4.0%. All the 156 strains were divided into 37 serotypes, with S. serotype typhimurium and enteritidis as the most common serotypes. 10 incidents of food poisoning were detected, of which 4 were caused by enteritidis and 3 by typhimurium. A suspected outbreak by enteritidis was discovered and under epidemiological investigation. The findings indicated that 2 of the 4 patients from this outbreak were infected with identical enteritidis isolates. 80% of the 229 isolates were found susceptible to cephalosporins and quinolone and 59.3% of them were multiresistant to the antibiotics.
Conclusion: S. enteritidis and S. typhimurium were the most common serotypes that caused infectious diarrhoea and food poisoning in Guangdong province.