Affiliation:
1. Department of Microbiology, All India Institute of Medical Sciences, Bhubaneswar, Orissa, India
2. Department of Anaesthesiology & Critical Care Medicine, All India Institute of Medical Sciences, Bhubaneswar, Orissa, India
3. Department of Infection Control Nursing, All India Institute of Medical Sciences, Bhubaneswar, Orissa, India
Abstract
Abstract
Objective The performance of Xpert Carba-R assay for the direct identification of carbapenemases directly from positive blood culture vials was evaluated.
Materials and Methods In total, 176 positively flagged blood culture vials, yielding carbapenem-resistant GNB (CR-GNB), were enrolled for the detection and differentiation of blaKPC, blaNDM, blaVIM, blaOXA-48, and blaIMP using Xpert Carba-R.
Results Klebsiella pneumoniae (76/176, 43.1%), Acinetobacter baumannii complex (67/176, 38%), and Escherichia coli (29/176,16.4%) were the predominant isolates. Overall, NDM production was the commonest (61/176, 34.6%), followed by the co-production of NDM + OXA-48 and the absence of any CR gene (44/176, 25%), followed by OXA-48 (27/176, 15.3%). In CR K. pneumoniae, the co-production of NDM + OXA-48 was most frequent (34/76, 44.7%), whereas in the A. baumannii complex, no CR gene was detected in the majority of isolates (38/67, 56.7%). bla NDM was the commonest gene in E. coli (18/29, 62%) and A. baumannii complex (26/67, 38.8%).
Conclusion Xpert Carba-R can identify the molecular mechanism of CR within hours after a blood culture turns positive and, thus, has the potential for optimization of antimicrobial therapy, choosing appropriate novel β-lactam combination agents, as well as infection control interventions.