title: Occurrence of co-existing bla VIM-2 and bla NDM-1 in clinical isolates of Pseudomonas aeruginosa from India.
abstract: BACKGROUND
  bla VIM-2 harboring Pseudomonas aeruginosa has been reported worldwide and considered as the most prevalent metallo-β-lactamase after NDM which are found horizontally transferable and mostly associated with integron gene cassettes. The present study investigates the genetic background, transmission dynamics as well as stability of bla VIM-2 in clinical isolates of P. aeruginosa harbor bla NDM-1 as well which were collected from October 2012 to September 2013.
  
  
  METHODS
  Two P. aeruginosa strains harboring bla VIM-2 along with bla NDM-1 were isolated from Silchar Medical College and Hospital, India. Genetic environment of these resistance determinants was determined and transferability was checked by transformation and conjugation assay which was further confirmed by Southern hybridization. Replicon typing was performed to determine the incompatibility group of the resistant plasmid and their stability was checked by serial passage method. Antimicrobial susceptibility pattern of the isolates was determined and their clonal relatedness was checked by pulsed field gel electrophoresis.
  
  
  RESULTS
  bla VIM-2 was found to be horizontally transferable through an Inc F type plasmid of approximately 30 kb in size. bla VIM-2 was found to be associated with integron gene cassette and was flanked by two different types of cassette arrays. Both the isolates were co-harboring bla NDM-1 which was carried within Inc N type of plasmid with an approximate 24 kb in size and associated with ISAba125 in their upstream region. Reduced susceptibility rate as well as high MIC range was observed in case of wild strains and transformants carrying bla VIM-2 and bla NDM-1.
  
  
  CONCLUSIONS
  The detection of this co-existence of multiple carbapenem resistance genes in this part of world is worrisome and further investigation is required in order to trace the source and to initiate proper treatment option.
authors.affiliation: Department of Microbiology, Assam University, Silchar, India.
authors.forename: Deepjyoti
authors.initials: D
authors.lastname: Paul
authors.affiliation: Department of Microbiology, Silchar Medical College and Hospital, Silchar, India.
authors.forename: Debadatta
authors.initials: D
authors.lastname: Dhar
authors.affiliation: Department of Microbiology, Assam University, Silchar, India.
authors.forename: Anand Prakash
authors.initials: AP
authors.lastname: Maurya
authors.affiliation: Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
authors.forename: Shweta
authors.initials: S
authors.lastname: Mishra
authors.affiliation: Department of Life Science and Bioinformatics, Assam University, Silchar, India.
authors.forename: Gauri Dutt
authors.initials: GD
authors.lastname: Sharma
authors.affiliation: Department of Microbiology, Silchar Medical College and Hospital, Silchar, India.
authors.forename: Atanu
authors.initials: A
authors.lastname: Chakravarty
authors.affiliation: Department of Microbiology, Assam University, Silchar, India. ab0404@gmail.com.
authors.forename: Amitabha
authors.initials: A
authors.lastname: Bhattacharjee
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D007194:India; D032023:Integrons; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001618:beta-Lactamases
keywords: Inc F type; Integron; Pseudomonas aeruginosa; bla NDM-1; bla VIM-2