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

Mahdi Hussain, Muheel Alammar
unpublished
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
more » ... d, 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. Introduction: Enterobacter spp. belonging to the family Enterobacteriaceae which are facultative anaerobic gram-negative bacilli, most species are motile with flagella and have class 1 fimbriae.They produce acid upon glucose fermentation , methyl red negative , and Voges-Proskauer positive , with an optimal growth temperature 30˚C30˚C, 80% are capsulated [1 ]. In human, multiple Enterobcter species are known to act as opportunistic pathogens, including E. cloacae, E. aerogenes , E .sakazakii ,E. gergoviae , and E. agglomerans. Enterobacter spp. which can cause numerous infections , including eye and skin infections , meningitis , bacteremia , pneumonia , urinary tract infections , wound , intestinal infections and surgical site infections[2]. Enterobacter involved in extra intestinal infections, which are known to possess virulence associated characteristics, they have the ability to adhere to and invade eukaryotic cells, once outside the gastrointestinal tract, they would take advantage of being able to chelate iron to survive and spread within the host .In enteric bacteria one of seven additional factors (Sigma-factors) bind RNAP (the complex is termed RNAP holoenzyme) and confer promoter recognition of specific groups of genes (termed regulons The sigma factors were σ70 RpoD(growth related/housekeeping), σ54 RpoN
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