title: Plasmid Profile Analysis and bla VIM Gene Detection of Metalo β-lactamase (MBL) Producing Pseudomonas aeruginosa Isolates from Clinical Samples.
abstract: BACKGROUND
  Pseudomonas aeruginosa is a frequent colonizer of hospitalized patients. They are responsible for serious infections such as meningitis, urological infections, septicemia and pneumonia. Carbapenem resistance of Pseudomonas aeruginosa is currently increasingly reported which is often mediated by production of metallo-β-lactamase (MBL). Multidrug resistant Pseudomonas aeruginosa isolates may involve reduced cell wall permeability, production of chromosomal and plasmid mediated β lactamases, aminoglycosides modifying enzymes and an active multidrug efflux mechanism.
  
  
  OBJECTIVE
  This study is aimed to detect the presence and the nature of plasmids among metallo-β-lactamase producing Pseudomonas aeruginosa isolates. Also to detect the presence of bla VIM gene from these isolates.
  
  
  METHODS
  Clinical isolates of Pseudomonas aeruginosa showing the metalo-β-lactamase enzyme (MBL) production were isolated. The MBL production was confirmed by three different methods. From the MBL producing isolates plasmid extraction was done by alkaline lysis method. Plasmid positive isolates were subjected for blaVIM gene detection by PCR method.
  
  
  RESULTS
  Two thousand seventy six clinical samples yielded 316 (15.22%) Pseudomonas aeruginosa isolates, out of which 141 (44.62%) were multidrug resistant. Among them 25 (17.73%) were metallo-β-lactamase enzyme producers. Plasmids were extracted from 18 out of 25 isolates tested. Five out of 18 isolates were positive for the blaVIM gene detection by the PCR amplification.
  
  
  CONCLUSIONS
  The MBL producers were susceptible to polymyxin /colistin with MIC ranging from 0.5 - 2μg/ml. Molecular detection of specific genes bla VIM were positive among the carbapenem resistant isolates.
authors.affiliation: Associate Professor, Department of Microbiology, Chettinad Hospital & Research Institute, Rajiv Gandhi Salai , Kelambakkam, Kanchipuram District, Chennai, Tamil Nadu, India .
authors.forename: Jayanthi
authors.initials: J
authors.lastname: S
authors.affiliation: Professor, Head of Department, Department of Microbiology, Chettinad Hospital & Research Institute, Rajiv Gandhi Salai , Kelambakkam, Kanchipuram District, Chennai, Tamil Nadu, India .
authors.forename: Jeya
authors.initials: J
authors.lastname: M
keywords: BlaVIM; Carbapenem resistance; Metallo-β-lactamase enzyme producers; Plasmids; Pseudomonas aeruginosa