Perfil plasmídico y resistencia antimicrobiana en cepas de Shigella aisladas en Cuba / Plasmidic profile and antimicrobial resistance in Shigella strains isolated in Cuba

RESUMEN

Se investigó un total de 240 cepas de Shigella, procedentes de los Centros Provinciales de Higiene y Epidemiología, durante el período de enero a diciembre de 2002. Estas especies constituyen los microorganismos aislados con mayor frecuencia de infecciones diarreicas agudas en los países en vías de desarrollo y en Cuba. Mediante el estudio de diferentes marcadores fenotípicos y genotípicos como serotipaje, estudios de resistencia a drogas antimicrobianas y perfil plasmídico, se investigó la relación epidemiológica de las cepas en estudio. Los serogrupos predominantes fueron S. flexneri 142 (59 %) y S. sonnei 76 cepas (32 %). El comportamiento de la susceptibilidad antimicrobiana mostró 79,2 % de cepas resistentes. Al analizar el comportamiento de S. flexneri según la región de origen, el perfil de resistencia y el perfil plasmídico se realizaron 2 agrupamientos y en el serogrupo S. sonnei se encontraron 5 agrupamientos. Los resultados obtenidos demuestran la heterogeneidad genética en las cepas de Shigella que circulan en el país.

ABSTRACT

240 Shigella strains from the Provincial Centers of Hygine and Epidemiology were investigated from Janaury to December, 2002. These species are the isolated microorganisms with the highest frequency of acute diarrheal infections in the developing countries and in Cuba. By the study of different phenotypic and genotypic markers as serotyping, studies of resistance to antimicrobial drugs and plasmidic profile, the epidemiological relation of the strains under study was analyzed. The predominating serogroups were 142 S. flexneri (59 %) and 76 S. sonnei strains (32 %). The antimicrobial susceptibility behavior showed 79.2 % of resistant strains. The resistance phenotypes most frequently found were streptomycin, trimethropim-sulfamethoxazole 71 (37.4 %); ampicillin, ampicillin-sulbactam, tetracycline, trimethroprim-sulfametoxazole, cloramphenicol 24 (12.7 %); ampicillin, ampicillin-sulbactram, streptomycin, tetracycline, amoxicyllin- clavulanic acid, trimethropim-sulfametoxazole 18 (9.5%). The plasmidic profiles detected in the S. flexneri serogrup were 6. Each profile contained between 2 and 7 plasmides and they were excluding. The diversity index was (ID 0.85), whereas in the S. sonnei serogroup there were 8 different profiles. Each one had between 2 and 8 plasmides with ID (0.86). On analyzing the behavior of S. flexneri according to the region of origen, the resistance profile and the plasmidic profile, 2 groupings were created.and 5 groupings were found in the S. sonnei serogroup. The results obtained showed the genetic heterogeneity in the Shigella strains that circulate in the country.