Detection of NDM-1 in Clinical Isolates of Klebsiella Pneumoniae from Northeast India 794-800
Dr. Giasuddin Ahmed
Professor, Department of Biotechnology, Gauhati University,
Guwahati-781014, Assam, India.
Introduction: The growing incidence of the resistance to carbapenems among the members of Enterobacteriaceae is of major concern throughout the world, as these drugs are often used now-a-days as the last line of effective treatment against the serious infections which are caused by multidrug resistant Enterobacteriaceae. We detected blaNDM-1 in the Klebsiella pneumoniae isolates which were collected from a tertiary care referral hospital in northeast India.
Materials and Methods: A total of 219 non-duplicated K. pneumoniae isolates were recovered from various clinical samples between August 2009 and July 2010. These isolates were screened for the detection of carbapenemase production on the basis of their reduced susceptibility to meropenem or ertapenem by the disc diffusion method. The screened isolates were further phenotypically studied for carbapenemase production by the modified Hodge test and the detection of metallo-β-lactamase production was carried out by using the combined disc test. All the screened isolates were also subjected to PCR detection of the blaNDM-1 gene and the additional bla genes which coded for TEM, SHV, CTX-M, and AmpC.
Results: Out of the 219 isolates, 19 were screened for the detection of carbapenemase production on the basis of their reduced susceptibility to meropenem or ertapenem. Both the phenotypic confirmatory tests showed positive results for all the screening positive isolates, although few weakly positive reactions for the modified Hodge test were observed. All the screened isolates were found to be positive for blaNDM-1. Each of the blaNDM-1 possessing isolates was also found to be positive for one or more additional bla genes.
Conclusion: This study indicated that the incidence of blaNDM-1, together with that of one or more additional bla genes among the K. pneumoniae isolates from hospitalized and non hospitalized patients in northeast India.