Pathogenic characteristics of Pseudomonas aeruginosa strains resistant to carbapenems associated with biofilm formation
Por:
Ochoa S.A., López-Montiel F., Escalona G., Cruz-Córdova A., Dávila L.B., López-Martínez B., Jiménez-Tapia Y., Giono S., Eslava C., HernándezCastro R., Xicohtencatl-Cortes J.
Publicada:
1 ene 2013
Categoría:
Pediatrics, Perinatology and Child Health
Resumen:
Background. In recent years, the worldwide emergence of multidrug-resistant strains of Pseudomonas aeruginosa has been observed. This opportunistic pathogen produces mechanisms of resistance to several antibiotics. The resistance to carbapenems in P. aeruginosa strains has been associated with bacterial biofilm formation, favored by the presence of exopolysaccharides (EPS) embedded in an extracellular matrix and to the production of type IV pili (T4P). We undertook this study to assess biofilm formation in clinical strains of P. aeruginosa resistant to carbapenems isolated at the Hospital Infantil de Mexico Federico Gomez (HIMFG) through quantification of total-reducing EPS and its association with the phenotypic expression of T4P. Methods. Antibiotic susceptibility tests were performed using the Kirby-Bauer method in 92 clinical isolates of P. aeruginosa; likewise, the minimum inhibitory concentration (MIC) was determined for imipenem (IMP) and meropenem (MEM) by the serial dilution method in agar plates with a Steers replicator. Production of metallo-ß-lactamase (MBL) was determined by the disk diffusion method and synergism. Biofilm formation was performed in clinical isolates of P. aeruginosa resistant to carbapenems through the quantification of crystal violet, total sugar (anthrone), and reducing sugar (DNS), in addition to the phenotypic expression of T4P activity of twitching motility. The genetic diversity of strains forming biofilm and producing reducing sugars was evaluated by pulsed-field gel electrophoresis (PFGE).
Filiaciones:
Ochoa S.A.:
Laboratorio de Bacteriología Intestinal, Mexico
López-Montiel F.:
Laboratorio de Bacteriología Intestinal, Mexico
Escalona G.:
Laboratorio de Bacteriología Intestinal, Mexico
Cruz-Córdova A.:
Laboratorio de Bacteriología Intestinal, Mexico
Dávila L.B.:
Laboratorio de Bacteriología Intestinal, Mexico
López-Martínez B.:
Laboratorio de Bacteriología Intestinal, Mexico
Jiménez-Tapia Y.:
Departamento Clínico, Hospital Infantil de México Federico Gómez, Mexico
Giono S.:
Laboratorio de Bacteriología Médica, Departamento de Microbiología, Instituto Politécnico Nacional, Mexico
Eslava C.:
Departamento de Salud Pública, Universidad Nacional Autónoma de México, Mexico
HernándezCastro R.:
Departamento de Ecología de Agentes Patógenos, Hospital General Dr. Manuel Gea González, México D.F, Mexico
Xicohtencatl-Cortes J.:
Laboratorio de Bacteriología Intestinal, Mexico
|