Occurrence of aac(6’)-Ib variants among Enterobacteriaceae: Is aac(6’)-Ib-cr the most predominant variant?

Occurrence of aac(6')-Ib variants among Enterobacteriaceae: Is aac(6')-Ib-cr the most predominant variant?

at codon 102 in the “cr” variant, it does not possess the BtsC1 restriction site. Hence, the PCR amplicons were digested with BtsC1 and the fragments were visualised in agarose gel electrophoresis. Strains harbouring wild-type variants of aac(6’)‐Ib gene shows fragments of 272 bp and 210 bp on gel electrophoresis and those which harbour aac(6’)‐Ib‐cr gene shows a single undigested DNA fragment ...

Identification of strain harboring both aac(6')-Ib and aac(6')-Ib-cr variant simultaneously in Escherichia coli and Klebsiella pneumoniae.

The aac(6')-Ib gene is the most prevalent gene that encodes aminoglycoside-modifying enzymes and confers resistance to tobramycin, kanamycin, and amikacin. The aac(6')-Ib-cr variant gene can induce resistance against aminoglycoside and fluoroquinolone simultaneously. Two main methods, sequence analysis and the restriction enzyme method, can detect the aac(6')-Ib-cr variant in clinical strains. ...

Prevalence of aac(6')-Ib-cr plasmid-mediated and chromosome-encoded fluoroquinolone resistance in Enterobacteriaceae in Italy

The spread of aac(6')-Ib-cr plasmid-mediated quinolone resistance determinants was evaluated in 197 enterobacterial isolates recovered in an Italian teaching hospital. The aac(6')-Ib-cr gene was found exclusively in Escherichia coli strains. The gene was located on a plasmid which presented additional ESBL genes. Most of the clinical strains were clonally related and displayed three point mutat...

Complete nucleotide sequences of plasmids pEK204, pEK499, and pEK516, encoding CTX-M enzymes in three major Escherichia coli lineages from the United Kingdom, all belonging to the international O25:H4-ST131 clone.

We determined the complete nucleotide sequences of three plasmids that encode CTX-M extended-spectrum beta-lactamases (ESBLs) in pulsed-field gel electrophoresis-defined United Kingdom variants (strains A, C, and D) of the internationally prevalent Escherichia coli O25:H4-ST131 clone. Plasmid pEK499 (strain A; 117,536 bp) was a fusion of type FII and FIA replicons and harbored the following 10 ...

Nobilis IB 4-91