Molecular study of some virulence factors encoding genes of Enterobacter spp. Isolated from different clinical specimens

The study aimed to isolation and identification of Enterobacter spp. from different clinical infections ,as well as virulence factors encoding gene were detected by PCR.The clinical specimens (100) were collected from patients suffering from different infectious from various hospitals of Najaf during the period from February 2011 to June 2012. Enterobacter isolates which were diagnosed according cultural and biochemical tests as well as API 20E . Eighty four isolates of Enterobacter were collected, from different samples which distributed in two species of Enterobacter , E.cloacae (89.3%) and E.sakazakii (10.7%) . The results showed that all isolates were produced of siderophore , and most isolates were capsule formation , but give negative result for haemolysin and protease. Also, 80 (95%) of Enterobacter has the CFA / III and 15(18 %) of isolates are bacteriocin production. The results showed that 26 (31%) of isolates were had rpoS gene , and these isolates were more resistance to stress conditions which lack the gene . The resistance was high in stationary phase than that in log phase. The result showed that all isolates were contained nitroreductase gene, but not had shiga like toxin gene.