Study of New Delhi Metallo Beta Lactamase and Oxacillinase beta Lactamase coexistence in Carbapenem Resistant Klebsiella Pneumoniae Obtained from Bloodstream Infections

Background: Carbapenem‑resistant Klebsiella pneumoniae(CRkp) is of utmost clinical importance because they challenge the armamentarium of the treating clinicians, hampering current treatment strategies. This study aimed to compare the outcomes of oxacillinases β-lactamases (OXA-48) and New Delhi metallo-β-lactamase (NDM-1)-producing CRKP isolates, the two most common carbapenemases reported from Worldwide including India, obtained from patients with bloodstream infections in an ICU in a tertiary care center in southern part of Rajasthan and to compare the different laboratory methods for their detection. Materials and methods: Klebsiella pneumoniaeisolates obtained from the blood culture of patients admitted to various ICUs were subjected to screened for carbapenem resistant detection by Combined Disc Test and subsequently by real time multiplex polymerase chain reactions. Antibiotic susceptibility tests (AST) were performed and clinical data were recorded. Results: A total of 91 Klebsiella pneumoniaeisolates were obtained from the blood culture. 63 isolates were showing resistance for carbapenem(meropenem/imipenem/ertapenem) by Antibiotic susceptibility test on Mueller Hinton Agar. In Combined Disc test 40 isolates were found positive for class B group of carbapenemases. Among 63 carbapenem resistance isolates, 50(79%) were found positive rest 13(20%) reported as negative by real time Multiplex RTpcr. There were 23(36%) isolates showing with NDM and OXA β-Lactamases coexistence in Carbapenem-Resistant Klebsiella Pneumoniae. Statistically significant differences were found in the AST pattern between the isolates with two genes. Conclusion: This study revealed the increase in trend of carbapenemase production and a high prevalence of coexistence of different carbapenemase gene that’s why Surveillance of carbapenemase genes in a hospital setting is essential. Key words: Carbapenem‑resistant Klebsiella pneumoniae (CRkp), oxacillinase β-lactamases (OXA-48) and New Delhi metallo-β-lactamase (NDM), Combined Disc test, real time Multiplex RTPCR