Phenotypic and genotypic studies of Nonfermenting bacteria from clinical samples

Abstract

Introduction: newline Nonfermenting Gram negative bacilli (Nonfermenters / NFGNB) are taxonomically diverse group of aerobic, nonsporing bacilli. Pseudomonas aeruginosa and Acinetobacter baumanii, the two important and more prevalent NFGNB from clinical samples. The study focuses on the prevalence of the metallo betalactamase producers, their antibiotic susceptibility pattern and presence of plasmids. Existence of the bla gene has been looked far. Biofilm production by Pseudomonas aeruginosa and the ways to control the production have been evaluated. newlineMaterial and methods: newline The isolation and identification of Nonfermenting Gram negative bacilli from clinical samples were carried out by standard protocol. Metallo and#946; lactamases enzyme production by the multidrug resistant Pseudomonas aeruginosa and Acinetobacter baumanii isolates were confirmed by different phenotypic methods. Plasmids were demonstrated from these isolates and the presence of the bla gene was detected by PCR amplification using appropriate primers. The amplified products of bla gene were sequenced and analysed. The biofilm formation by Pseudomonas aeruginosa strains and its inhibition by the amikacin was demonstrated by in-vitro studies. newlineResults: newline A total of 2018 NFGNB were isolated from clinical samples. Among them 48% were Pseudomonas aeruginosa and 24% Acinetobacter baumanii. The plasmids were demonstrated from 50 % of Pseudomonas aeruginosa isolates and 15 % of Acinetobacter baumanii isolates. The blaVIM metallo and#946; lactamase genes were detected in 80% of Pseudomonas aeruginosa isolates. Sequencing of the blaVIM genes of Pseudomonas aeruginosa, blaVIM and blaOXA genes of Acinetobacter baumanii was carried out. The resulting sequences were compared with those available in GenBank (www.ncbi.nih.gov/BLAST). The gene accession numbers were KF975367, KF975368, KF975369. newline A qualitative invitro analysis of the biofilm formation of the Pseudomonas aeruginosa was studied. The amikacin-agarose coated catheter tips significantly reduced the biofilm formation. newlineConclusion: newline Findings of the study reveals that MBLs are emerging as major cause of broad spectrum and#946; lactam resistance. newline