[Prevalence of Plasmid-mediated Quinolone Resistance Determinant Aac(6')-Ib-cr Among ESBL Producing Enterobacteria Isolates from Chilean Hospitals]

Introduction: The frequency of aac(6')-Ib-cr gene in ESBL-producing strains of Klebsiella pneumoniae and Escherichia coli is unknown, in Chile.

Methodology: The aac(6')-Ib and aac(6')-Ib-cr genes were investigated using polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), and sequencing, in strains isolated from 10 Chilean hospitals between 2008-2009.

Results: The aac(6')-Ib-cr gene was detected in 54% of K. pneumoniae and 74% of E. coli strains. The CIM(50) of CIP was higher among strains harboring aac(6')-Ib-cr, 8 times higher in K. pneumoniae and 4 times higher in E. coli. Moreover, both aac(6')-Ib and aac(6')-Ib-cr were simultaneously found in 13 K. pneumoniae and 3 E. coli isolates.

Conclusion: This is the first report of aac(6')-Ib-cr in ESBL-producing strains of K. pneumoniae and E. coli isolated from in-patients in Chilean hospitals located along an area of more than 2,800 Km.