Emergence of Klebsiella pneumoniae isolate co-producing NDM-1 with KPC-2 from India.

References 1 Cuzon G, Naas T, Truong H et al. Worldwide diversity of Klebsiella pneumoniae that produces b-lactamase bla KPC-2 gene. related Klebsiella pneumoniae isolates of sequence type 258 producing plasmid-mediated KPC carbapenemase in Norway and Sweden. et al. Plasmid-mediated carbapenem-hydrolyzing enzyme KPC-2 and ArmA 16S rRNA methylase conferring high-level aminoglycoside resistance in carbapenem-resistant Enterobacter cloacae in China. Sir, The emergence of NDM-1-producing isolates and their sources have been clearly identified in several countries worldwide. In particular, the bla NDM-1 gene was identified in various genera of Enterobacteriaceae and in non-fermenting Gram-negative bacilli from environmental samples in India. 3 Furthermore, the increasing co-production of NDM-1 with other carbapenemases has been detected amongst isolates of Enterobacteriaceae and Acinetobacter sp. in many parts of India. 4 – 7 We report here the isolation of a strain of Klebsiella pneumoniae (designated IR98) from a urine sample from a middle-aged patient admitted to the intensive care unit of a tertiary care hospital in Chennai, India in July 2010. Species identification and antibiotic susceptibility, determined using an automated system (VITEK-2, bioMérieux Inc.), showed wide-spectrum resistance to b-lactams, aminoglycoside, fluoroquinolones, co-trimoxazole, nitrofurantoin and tigecycline, but susceptibility to colistin and fos-fomycin, according to CLSI guidelines. 8 MICs of various antibiotics were determined using the agar dilution method, while the tigecycline MIC was determined using the broth microdilution method. European Committee on Antimi-crobial Susceptibility Testing (EUCAST) breakpoints were applied to interpret the susceptibilities. 9 The isolate was highly resistant to imipenem (256 mg/L), meropenem (128 mg/L), ceftazidime The double-disc synergy test (DDST), modified Hodge test (MHT) 10 and combined-disc synergy test (CDST) 11 were used for the detection of metallo-b-lactamases (MBLs), other carbapenemases and KPC, or KPC with MBLs. The simultaneous production of MBL and KPC-like carbapenemases was confirmed by positive DDST, MHT and CDST with meropenem discs containing both EDTA and phenylboronic acid (PBA) or EDTA, while meropenem discs supplemented with PBA were negative. PCR assays for genes encoding b-lactamases 12 and 16S rRNA methylases 13 revealed the presence of bla NDM-1 , bla KPC-2 , bla CTX-M-15 , bla SHV-12 , bla TEM-1 , bla OXA-1 and rmtB genes. Plasmid analysis using the Kieser technique 14 revealed that K. pneumoniae IR98 harboured four plasmids, with sizes of 160, 120, 70 and 40 kb, using Escherichia coli NCTC 50192 as a reference. 15 To study the transferability of these plasmids (encoding the resistance determinants), transconjugation and transformation …