Objective: The aim of this study was to describe resistance patterns of Citrobacter spp., Serratia spp. and Providencia spp. isolated from clinical samples in a general hospital of Caracas, Venezuela in a 7-year-period. Materials and Methods: The study was conducted in the period 1997-2003. Antibiotic-sensitivity testing was performed by disk diffusion as recommended by the NCCLS. Results: For the studied period, 221 clinical strains were isolated; 61.5% of Citrobacter freundii, 24.9% of Serratia marcescens, 6.8% of Serratia liquefasciens, 5.4% of Providencia rettgeri and 1.4% of Providencia stuartii. C. freundii showed 33.3% of resistance to norfloxacin, 32.8% to piperacillin, 27.3% to levofloxacin. Overall better antimicrobial susceptibility activity was with cefepime, 94.8%, imipenem, 99.1%, and meropenem, 100%. Extended spectrum b-lactamases activity was detected in 1.5% of isolated strains. S. marcescens showed 38.8% of resistance to tobramycin, 32.1% to gentamicin, 30.8% to amikacin, but was susceptible for ciprofloxacin, 94.1%, imipenem, 100%, and meropenem, 100%. P. rettgeri showed 37.5% of resistance to tobramycin, 25.0% to gentamicin and 20.0% to ciprofloxacin. Any isolate was resistance to meropenem. Conclusion: The emergence and spread of multi-drug resistant bacilli as Citrobacter, Serratia and Providencia in the nosocomial setting should be understood in terms of a complex interplay of bacterial clonality, resistance genes and genetic structures promoting rapid dissemination of antimicrobial resistance. Intervention strategies in the forthcoming scenario should identify existing epidemic and/or endemic situations involving clonal organisms or resistance genes carried by epidemic gene capture units. Antimicrobial activity surveillance should be continued in the hospital setting.
2006-03-31 | 3,835 visitas | Evalua este artículo 0 valoraciones
Vol. 3 Núm.2. Abril-Junio 2005 Pags. 54-64 Acta Cient Estud 2005; 3(2)