Genotyping of MDR Acinetobacter baumannii to detect the Co–existence of MBL and Carbapenemase Genes Including NDM–1 and the Sequencing of the Most Prevalent Resistance Genes

Mrs. Aparna Shivaprasad; Dr.Beena Antony; Dr. Chaitra.C

Volume : VII, Issue : X, October - 2017

Genotyping of MDR Acinetobacter baumannii to detect the Co–existence of MBL and Carbapenemase Genes Including NDM–1 and the Sequencing of the Most Prevalent Resistance Genes

Mrs. Aparna Shivaprasad, Dr. Beena Antony, Dr. Chaitra. C

Abstract :

Multidrug–resistance is quite common among non–fermenting gram negative rods including Acinetobacter baumannii (A.baumannii). The rapid spread of multidrug–resistant A.baumannii in clinical settings has made the treatment options difficult for clinicians. Molecular characterization of suspected pathogens might help to provide an idea about the acquisition/presence of resistance genes among them and to provide appropriate therapy. Materials and Methods– 251 isolates of A.baumannii were collected from various samples and screened by phenotypic methods, were subjected to PCR to detect the presence of drug resistance genes [Metallo–β–lactamase (MBL) and Oxacillinase genes (OXA)] – bla_IMP, bla_VIM, bla_NDM–1, bla_OXA–23, bla_OXA40, bla_OXA51 and bla_OXA58. Five isolates were selected and sequencing was done by Sanger’s sequencing method for each gene.Results and Discussion–The 251 isolates showed the co–existence of various MBL and Oxacillinase [Carbapenemase] genes that contributed to their drug resistance. The analysis of sequencing done showed mutations in bla_OXA–51, bla_O_XA–58 and bla_NDM–1genes. There was no difference in bla_OXA–23gene sequence. Conclusion–The co–existence of multiple Oxacillinases [Carbapenemases] and MBLs along with other resistance mechanisms might result in treatment failure. Genotypic screening should be performed for the detection of resistance genes in nosocomial MDR and XDR A.baumannii isolates.