BACKGROUND: Salmonellosis is one of the most important
zoonotic diseases throughout the world. OBJECTIVES: The
purpose of this study was to characterize a large collection of
Salmonella isolates from different poultry sources in Iran.
METHODS: A total of 123 Salmonella isolates from different
poultry sources were subjected to drug susceptibility test,
hemolysin production, motility test, and plasmid profile (50
isolates). RESULTS: Seventy-one resistance patterns were found
to 29 antimicrobial agents among 123 Salmonella isolates, in
which 81% of isolates were resistant to more than one
antibacterial agent. The resistance patterns of 123 isolates to 10
commonly used antibacterials in Iranian poultry industry were
also quite variable and included 31 patterns. Four different
plasmid patterns were found among 50 Salmonellaisolates. Fifty
four percent of Salmonella isolates harbored one or three
plasmids with approximate molecular size ranging from 2.3 to
68 kb. No plasmid was detected in 46% of isolates. Aband of 68
kb size was detected in all isolates that harbored plasmid. All
isolates were motile but no isolate showed hemolysin
production. CONCLUSIONS: The frequency of resistance to
antibacterial agents among avian Salmonella isolates is a major
public health concern.