Molecular Mechanisms Associated with Nosocomial Carbapenem-resistant Acinetobacter baumannii in Mexico
Por:
Alcántar-Curiel M.D., García-Torres L.F., González-Chávez M.I., Morfín-Otero R., Gayosso-Vázquez C., Jarillo-Quijada M.D., Fernández-Vázquez J.L., Giono-Cerezo S., Rodríguez-Noriega E., Santos-Preciado J.I.
Publicada:
1 oct 2014
Categoría:
Medicine (miscellaneous)
Resumen:
Background and Aims. Acinetobacter baumannii is an emerging pathogen
worldwide that is most commonly associated with nosocomial infections
and multi-drug resistance. In the present study we determined the
mechanisms of carbapenem resistance and clonal diversity of A. baumannii
nosocomial isolates in Hospital Civil de Guadalajara, Mexico.
Methods. A total of 303 clinical isolates of A. baumannii identified
during a period expanding from 2004-2011 were analyzed for carbapenem
resistance using several microbiological and molecular methods. Clonal
relatedness of these isolates was determined using pulsed-field gel
electrophoresis.
Results. Of the 303 isolates, 84% were resistant to meropenem, 71.3%
to imipenem and 78.3% the resistant isolates were positive for
metallo-beta-lactamases as determined by the phenotypic assay. In
addition, 49.6% of carbapenem-intermediate or -resistant isolates
carried the bla(OXA-72) gene and 1.2% carried the bla(VIM-1) gene.
Efflux pump phenotype was responsible for reduced susceptibility to
meropenem in 14.5% and to imipenem in 31.6% of the resistant isolates,
respectively in the presence of the efflux pump inhibitor, carbonyl
cyanide 3-chlorophenylhydrazone. Strains representing different
carbapenem-resistant patterns exhibited reduced expression of 22, 29,
33, and 43 kDa OMPs. Among the bacterial collection studied, 48
different clones were identified, two of which were predominant and
persistently transmitted.
Conclusions. Carbapenemase production in combination with efflux pump
expression, reduction in OMPs expression and the cross-transmission of
clones appear to be major contributors to the high frequency of
carbapenem-resistance observed in A. baumannh. To our knowledge, this is
the first study to define the molecular mechanisms associated with
carbapenem-resistance in A. baumannii in Mexico. (C) 2014 IMSS.
Published by Elsevier Inc.
Filiaciones:
Alcántar-Curiel M.D.:
Univ Nacl Autonoma Mexico, Fac Med, Unidad Invest Med Expt, Mexico City 04510, DF, Mexico
García-Torres L.F.:
Univ Nacl Autonoma Mexico, Fac Med, Unidad Invest Med Expt, Mexico City 04510, DF, Mexico
González-Chávez M.I.:
Univ Nacl Autonoma Mexico, Fac Med, Unidad Invest Med Expt, Mexico City 04510, DF, Mexico
Morfín-Otero R.:
Hospital Civil de Guadalajara FAA, Instituto de Patología Infecciosa CUCS, UDG, Jalisco, Mexico
Gayosso-Vázquez C.:
Univ Nacl Autonoma Mexico, Fac Med, Unidad Invest Med Expt, Mexico City 04510, DF, Mexico
Jarillo-Quijada M.D.:
Univ Nacl Autonoma Mexico, Fac Med, Unidad Invest Med Expt, Mexico City 04510, DF, Mexico
Fernández-Vázquez J.L.:
Univ Nacl Autonoma Mexico, Fac Med, Unidad Invest Med Expt, Mexico City 04510, DF, Mexico
Giono-Cerezo S.:
Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, México D.F., Mexico
Rodríguez-Noriega E.:
Hospital Civil de Guadalajara FAA, Instituto de Patología Infecciosa CUCS, UDG, Jalisco, Mexico
Santos-Preciado J.I.:
Univ Nacl Autonoma Mexico, Fac Med, Unidad Invest Med Expt, Mexico City 04510, DF, Mexico
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