Distribution of Biofilm-associated Genes among Acinetobacter baumannii by in-silico PCR

Abstract

Background: Acinetobacter baumannii is a coccobacillus that is Gram negative, non motile, non fermentative and oxidase negative. It is the most common and successful nosocomial pathogen recognised by WHO. This dreadful pathogen causes urinary tract infections, ventilator associated pneumonia (VAP), bacteremia, etc., These infections are most common in hospital wards especially Intensive Care Unit (ICU). The infections are due to biofilm formation by the virulent genes of A. baumannii, and the common biofilm-associated genes of A. baumannii were bap, csuE, fimH, epsA, bfmS, ptk, pgaB, ompA, blaPER-1. Among these, bap, epsA and ompA genes are highly prevalent among the clinical strains of A. baumannii. Aim:  To detect the three vital biofilm-associated genes of A. baumannii by in-silico PCR analysis. Materials and Methods: 19 isolates of A. baumannii were selected and 3 target genes, namely epsA, ompA and bap gene were used for the amplification process through in-silico PCR simulation tools. Evolutionary analysis was done for the ompA gene. Results: The epsA gene was expressed in 10.52% of the total strains selected with the highest occurrence of ompA gene as 57.89%. bap gene was not observed from the study strains included. From evolutionary analysis based on ompA distributed strains, the Acinetobacter baumannii SDF and Acinetobacter baumannii BJAB0715 might be the parental strains where the evolution of strains would have started. Through successive generations, the Acinetobacter baumannii MDR-ZJ06 and Acinetobacter baumannii TYTH-1 had become the multidrug resistant strains present in the environment. Conclusion: The findings of the study confirms the distribution of epsA and ompA genes among the 19 different strains of A. baumannii. The study suggests periodical monitoring of biofilm based virulence genes among the clinical strains and to curtail the A. baumannii infections.