Análisis de resistencia a antibióticos en cepas que producen infecciones nosocomiales en el Hospital para el Niño del DIF, en el Estado de México

Bacterial strains producing nosocomial infections at Hospital para el Niño, DIF, in Toluca, State of Mexico (Mexico), during 1992 were analysed in regara to their resistance to antibiotics routinely used in that hospital to fight such infections. The strains under study belonged to three groups: Enterobacteriaceae, Pseudomonas, and Stapbylococcus. Two (Aztreonam and Ceftazidime) out of seven antimicrobial agents assayed in vitro against the Enterobacteriaceae strains were relatively effective since oniy 16% and 20% ofthe strains were resistant, respectívely. This data contrast the average rate of resistant strains to the other five antibiotics included (93%). Five antibiotics were assayed with the Pseudomonas strains, resulting that Aztreonam and Ceftazidime had again the lowest rotes of resistant strains altbough the differences were not as marked as they were for Enterobacteriaceae strains. Six antibiotics were studied on the Stapbylococcus strains, and none of them outstoodfor having a specially high efficacy, being Rifampicin the antibiotic with tbe lowest rate ofresistant strains (54.5%). It is very important to be aware of the phenomenon of antibiotic resistance in tbe hospitals, to be able to extend tbe lifespan of antibiotics such as Aztreonam and Ceftazidime in this study, which prove effective because of tbeir relatively low rotes of resistant strains. The excessive usage ofthese drugs will lead to growing rates of resistant strains.Las infecciones nosocomiales son aquéllas que se presentan en los pacientes durante su estancia en un hospital, sin que al ser admitidos se encuentren dichas infecciones manifiestas o en período de incubación (Schaberg, et. al. 1980).La prevalencia de los microorganismos que producen infecciones nosocomiales es muy significativa debido a que poseen características de invasividad y defensa especialmente desarrolladas, particularmente en lo concerniente a su capacidad para proliferar en ambientes con concentraciones importantes de diversos antibióticos.1El fenómeno de la resistencia bacteriana a los antimicrobianos en general es cada vez más agudo.2 En los hospitales esta situación es influida fuertemente por el empleo abundante que se hace de los antibióticos, en ocasiones de forma justificada y en ocasiones no (Moss, et. al. 1981 y Narsallah, 1983). La consecuencia lógica del uso excesivo de los antibióticos es la proliferación de los microorganismos resistentes (Williams, 1988) por un mecanismo simple de selección