Antimicrobial Susceptibility of Imipenem-Resistant Pseudomonas aeruginosa strains in a General Hospital of Venezuela: a Retrospective Preliminary Contribution to OprD and Efflux Systems Resistance Mechanisms

Autores: Rodríguez Cruz N, Rodríguez Morales Alfonso J, Calvo Alberto, García Ada, Duque Carmen Lucía, Jiménez Ivette, Meijomil Pilar, Barbella Aponte Rosa A

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Introduction Pseudomonas aeruginosa is a versatile gram-negative bacterium that grows in soil, marshes and coastal marine habitats, as well as on plant and animal tissues. As a human pathogen is involved mainly in bacteremia in burn victims, urinary tract infections (especially in catheterized patients) and hospital-acquired pneumonia in patients on respirators. P. Aeruginosa infections are particularly difficult to treat because of intrinsic resistance to antibiotics. This intrinsic multidrug resistance results from the synergy between broadly specific drug efflux pumps and a low degree of outer membrane permeability. For the carbapenem antimicrobials, the resistance is mostly mediated by OprD loss, which primarily confers a resistance to imipenem but also confers a low grade resistance to meropenem. Based on the carbapenem susceptibility patterns, the clinical isolates of carbapenem-resistant P. Aeruginosa could be divided into three groups as the imipenem-resistant and meropenem-sensitive group (IMI-R, MER-S), the imipenem-sensitive and meropenem-resistant group (IMI-S, MER-R), and the imipenem-resistant and meropenem-resistant group (IMI-R, MER-R). A second common type of resistance observed involves mutants of the nfxC class, which show an increased resistance to chloramphenicol, quinolones, and imipenem. They tend to show increased susceptibility towards most –lactam antibiotics (except imipenem) and aminoglycoside antibiotics.

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2006-04-25   |   1,741 visitas   |   Evalua este artículo 0 valoraciones

Vol. 4 Núm.1. Enero-Marzo 2006 Pags. 5-11 Acta Cient Estud 2006; 4(1)