Antimicrobial Susceptibility and Molecular Typing of Salmonella Agona Isolated from Humans and Other Sources

Salmonella enterica serotype Agona (Salmonella Agona) has been among the top 10 serotypes that cause human diarrheal diseases in China. A total of 95 Salmonella Agona (67 from humans, and 28 from animals, food of animal origins, and environmental sources) recovered in Shanghai, China from 2005 to 2011 were subjected to antimicrobial susceptibility testing and molecular subtyping using pulsed-field gel electrophoresis (PFGE). Approximately 68.4% of the Salmonella Agona isolates were pansusceptible to 15 antimicrobial agents tested, and 4 isolates (4.21%) were resistant to at least 3 antimicrobials. PFGE analysis resulted in 41 unique patterns, of which 4 major PFGE patterns (X3, X4, X5, and X6) were grouped together at 96.1% similarity. Isolates of the four patterns included those from food (pork, beef, and chicken) and humans. Our findings showed that the same clones of Salmonella Agona were recovered from human patients and food, and that food of animal origin was potentially a major vehicle of Salmonella Agona in human salmonellosis in Shanghai.