Characterization of phenotypically metallo-β-lactamase positive Pseudomonas aeruginosa human isolates from Himachal Pradesh for MBL genes (blaVIM-2 and blaIMP-1), integrase gene class 1, 2, 3 (int1, int2 and int3) and sulphonamide resistance gene (sul1)

Abstract

Background & objectives: The present study highlights the occurrence of MBL gene (blaVIM-2), integron class 1 (int1) and sulphonamide resistance (sul1) genes in P. aeruginosa isolates recovered from patients of Shimla region of India. Methods: P. aeruginosa isolates detected positive for MBL by Combined Disc and Ezy MIC tests were characterized by PCR amplification of segments of blaIMP-1 and blaVIM-2, integrase genes encoding integron classes int1, int2 and int3, and sul1 gene. The nucleotide sequence homologies with the published sequences of Pseudomonas spp and other gram-negative bacilli were determined. Results: All the confirmed isolates of P. aeruginosa were further subjected to nucleotide sequencing of 16SrRNA amplicons. MBL gene (blaVIM-2) was amplified in six out of 27 MBL positive isolates, int1 gene in eleven and sul1 gene in 14 MBL positive isolates .Only one isolate Pa138 carried both blaVIM-2 and int1 genes. The specificity was established by nucleotide sequencing of the amplicons. Interpretation & Conclusion: The occurrence of blaVIM-2, int1 and sul1 genes has been reported in the P. aeruginosa isolates of Shimla region of Himachal Pradesh. The studies might be useful to the clinicians for selecting suitable antibiotic for treating and controlling P. aeruginosa infections in this region.

Keywords

• P. aeruginosa
• MBL
• integron
• blaVIM-2
• int1
• sul1