Enterobacteriaceae isolates carrying the New Delhi metallo-β-lactamase gene in Yemen

Ten carbapenem-resistant Enterobacteriaceae (eight Klebsiella pneumoniae isolates and two Enterobacter cloacae) isolates from Yemen were investigated using in vitro antimicrobial susceptibility testing, phenotypic carbapenemase detection, multilocus sequence typing (MLST) and replicon typing. Carbapenemase, extended-spectrum Hactamase (ESBL) and plasmidmediated quinolone resistance determinant genes were identified using FOR and sequencing. All of the 10 carbapenem-resistant Enterobacteriaceae were resistant to beta-lactams, tobramycin, ciprofloxacin and cotrimoxazole. Imipenem, doripenem and meropenem MICs ranged from 2 to >32 mg l(-1) and ertapenem MICs ranged from 6 to >32 mg l(-1). All of the K. pneumoniae isolates showed ESBL activity in phenotypic tests. Genes encoding bla(NDM) were detected in all strains. All K. pneumoniae strains produced CTX-M-15 ESBL and SHV beta-lactamases. TEM-1 beta-lactamase was detected in seven isolates. Nine isolates were qnr positive including OnrB1, CtnrA1 and CtnrS1, and six isolates produced AAC-6'-lb-cr. MLST identified five different sequence types (STs): ST1399, ST147, ST29, ST405 and ST340. Rep licon typing showed the presence of IncFII1K plasmids in four transforrnants. To the best of our knowledge, this is the first report of NDM-1-producing Enterobacteriaceae isolates in Yemen.