Evaluation the virulence factors and biofilm formation ability of isolated Acinetobacter baumannii strains from the teaching hospitals in Shiraz-Iran.

Background and Aim : Acinetobacter baumannii as an opportunistic pathogen with the ability to form biofilm on biotic and abiotic surfaces and is one of the concerns related to nosocomial infections and hospital outbreaks worldwide. The aim of this study was to evaluate the presence of various virulence factors and the ability of isolated Acinetobacter baumannii bacteria from the hospitalized patients in Shiraz- Iran. Methods : In this study the prevalence of A. baumannii isolates in clinical samples were investigated through the conventional biochemical tests. Also polymerase chain reaction (PCR) was used to evaluate the presence of virulence factors. Moreover, the biofilm formation ability was determined by microtiter plate methods.Results : Out of ۱۲۰ samples, about ۱۰۰ isolate were confirmed as Acinetobacter baumannii. Although the presence of iutA (۱۰%) and papC (۵%) genes were affirmed by PCR method, the isolates were negative for the presence of cnf۱, cnf۲, fbn and kpsMT۲. Additionally, the phenotypic biofilm formation (microtiter plate) showed that ۶۱% of the Acinetobacter baumannii isolates had the ability to form biofilm. (p=۰.۰۲۸). Besides, there was no significant relationship between the presence of iutA and papC genes and biofilm formation. Conclusion : the remarkable rates of Acinetobacter baumannii isolates were able to form biofilm which promotes their survival and growth in various environments and also in hospitals. Furthermore, we confirmed that iron uptake and fimbriae production plays an important role in virulence and adherence of Acinetobacter baumannii in order to initiate its pathogenesis.

کلیدواژه ها:

Acinetobacter baumannii ، Polymerase chain reaction ، Biofilm ، iutA ، papC.