Abstract

Muhammad Aziz, Nuri Bassim Mikhail, Ali H. Donnyand Ashur D. Sargisand Baqir Al-Sadr

In this study, several Salmonella (n=25) isolated from turkey meat were characterized using conventional culture methods, biochemical, serological, antimicrobial testing and analysed for presence of virulence genes. For molecular analysis, the 16S rDNAs of all strains of Salmonella were sequenced and used for construction of a phylogenetic tree. Six different serotypes were identified of which Salmonella Saintpaul (n=10) was the most frequent, followed by Salmonella Agona (n=6), Salmonella Typhimurium (n=4), Salmonella Heidelberg (n=3), Salmonella Infantis (n=1) and Salmonella Bredeney (n=1). All strains were positive for nine virulence genes (spiA, sifA, spaN, sopB, sipB, iroN, orgA, sitC and prgH), but none were positive for spvB genes. Salmonella isolates most frequently exhibiting resistance to 3-8 antibiotics were Agona (83%), Typhimurium (75%) and Saintpaul (60%), though one strain (S. Agona) is an Extended-spectrum beta-lactamase (ESBL) with a minimal inhibitory concentration (MIC) for ceftriaxone (16 µg/Ml). Salmonella strains were clustered into four phylogenetic groups and three sub clusters. However, S. Infantis, S. Bredeney and S. Agona AE136/2 betalactamase producing (ESBL) were placed separately on side branches separate from the remaining strains, while 100% (n=25) strains possessed a 16S rDNA sequence with ≥97% similarity to that of a genus Salmonella.