The emergence of OXA-48- and NDM-1-positive Klebsiella pneumoniae in Riyadh, Saudi Arabia

Objectives: To investigate the emergence of NDM-, OXA-48-, and VIM-producing Klebsiella pneumoniae in Saudi Arabia.

Methods: From June to December 2011, we obtained K. pneumoniae isolates with reduced sensitivity to carbapenem identified in Riyadh, Saudi Arabia. Only non-duplicate clinical and surveillance isolates obtained from inpatients were included. PCR amplification was carried out for the detection of extended-spectrum beta-lactamase genes (blaCTX-M, blaTEM, blaSHV) and carbapenemase genes (blaKPC, blaVIM, blaIMP, blaNDM, and blaOXA-48). Susceptibility to imipenem, meropenem, amikacin, gentamicin, trimethoprim-sulfamethoxazole, and colistin was determined.

Results: Of the 60K. pneumoniae isolates studied, 45 were from patients in the intensive care unit. Forty-seven isolates harbored blaOXA-48, 12 were positive for blaNDM, and one for blaVIM. No isolate harbored a combination of these resistance genes. No isolate harbored blaKPC or blaIMP. All 37 blaCTX-M-positive isolates belonged to CTX-M group 1, and 29 were positive for a combination of blaCTX-M and blaOXA-48. blaTEM and blaSHV genes were found in 17 and 39 isolates, respectively. All isolates were imipenem- and meropenem-resistant, with a high rate of co-resistance to the other antibiotics. Three blaOXA-48-positive isolates with colistin resistance were detected.

Conclusion: Multidrug-resistant K. pneumoniae isolates harboring blaOXA-48, blaNDM, and colistin resistance are emerging in Saudi Arabia.