ABSTRACT
BACKGROUND: Macrolide resistance in Streptococcus pneumoniae is coded by the ermB and mefA/E genes. The aim of this study was to determine the status of macrolide-resistance, the molecular mechanisms involved, the serogroup relationships, and the level of co-resistance in S. pneumoniae isolates from Gran Canaria and Lanzarote, in the Canary Islands, Spain. METHODS: Macrolide resistance phenotypes were investigated in 261 S. pneumoniae clinical isolates over a two-year period (2004 and 2005). Genotypes were determined by PCR (detection of ermB and mefA/E genes). RESULTS: Overall macrolide resistance was 40.6% (106 isolates); 79.2% (84) of resistant isolates presented the MLSB phenotype (98.8% harbored the ermB gene), with a predominance of serogroup 19, and 20.8% (22) presented the M phenotype (77.3% displayed the mefA/E gene), all associated with serogroup 14. Worthy of note, the M phenotype was found in 8 invasive isolates from Lanzarote (80%) all from serogroup 14. The ermB and mefA/E genes were detected in 7 isolates belonging to serogroup 19. Absence of co-resistance was observed most frequently in serogroup 14 (66.7%). Co-resistance with penicillin G, tetracycline, and trimethoprim-sulfamethoxazole was associated with serogroup 19 (36.8%). Two isolates (0.8%) were resistant to telithromycin. CONCLUSION: The frequency of macrolide resistance mechanisms in the Canary Islands is different from that observed in the rest of Spain, particularly in Lanzarote, where 80% of isolates harbored the mefA/E gene and belonged to serogroup 14.
Subject(s)
Drug Resistance, Multiple, Bacterial , Macrolides/pharmacology , Pneumococcal Infections/microbiology , Streptococcus pneumoniae/drug effects , Adolescent , Adult , Atlantic Islands/epidemiology , Bacterial Proteins/genetics , Child , Child, Preschool , Drug Resistance, Multiple, Bacterial/genetics , Female , Genotype , Humans , Infant , Male , Membrane Proteins/genetics , Phenotype , Pneumococcal Infections/epidemiology , Serotyping , Spain/epidemiology , Streptococcus pneumoniae/classification , Streptococcus pneumoniae/genetics , Streptococcus pneumoniae/isolation & purificationABSTRACT
Introducción. La resistencia a macrólidos en Streptococcus pneumoniae está codificada por los genes ermB y mefA/E. Nuestro objetivo fue conocer el estado de resistencia a macrólidos, los mecanismos moleculares implicados, la relación con los serogrupos y la corresistencia en las islas de Gran Canaria y Lanzarote. Métodos. Sobre 261 cepas aisladas durante dos años (2004-2005), se estudiaron los fenotipos de resistencia a macrólidos. Los genes ermB y mefA/E se detectaron por reacción en cadena de la polimerasa (PCR). Resultados. La resistencia global a macrólidos fue del 40,6% (106 cepas). El 79,2% (84) de las cepas presentó el fenotipo MLSB (el 98,8% portó el gen ermB), con predominio del serogrupo 19. El 20,8% (22) de las cepas presentó el fenotipo M (el 77,3% portó el gen mefA/E), con predominio del serogrupo 14. Destacamos la presencia del fenotipo M (8 cepas, 80%) en cepas invasivas de Lanzarote, todas del serogrupo 14. Se detectaron 7 cepas del serogrupo 19 portadoras de los genes ermB y mefA/E. La ausencia de corresistencia se relacionó con el serogrupo 14 (66,7%). La corresistencia con penicilina G, tetraciclina y trimetoprim-sulfametoxazol se relacionó con el serogrupo 19 (36,8%). Dos cepas (0,8%) fueron resistentes a telitromicina. Conclusión. La frecuencia de los mecanismos de resistencia a macrólidos en Canarias es diferente a la del resto de España, en particular en Lanzarote, con un predominio del gen mefA/E (80% de las cepas, todas ellas del serogrupo 14) (AU)
Background. Macrolide resistance in Streptococcus pneumoniae is coded by the ermB and mefA/E genes. The aim of this study was to determine the status of macrolide-resistance, the molecular mechanisms involved, the serogroup relationships, and the level of co-resistance in S. pneumoniae isolates from Gran Canaria and Lanzarote, in the Canary Islands, Spain. Methods. Macrolide resistance phenotypes were investigated in 261 S. pneumoniae clinical isolates over a two-year period (2004 and 2005). Genotypes were determined by PCR (detection of ermB and mefA/E genes). Results. Overall macrolide resistance was 40.6% (106 isolates); 79.2% (84) of resistant isolates presented the MLSB phenotype (98.8% harbored the ermB gene), with a predominance of serogroup 19, and 20.8% (22) presented the M phenotype (77.3% displayed the mefA/E gene), all associated with serogroup 14. Worthy of note, the M phenotype was found in 8 invasive isolates from Lanzarote (80%) all from serogroup 14. The ermB and mefA/E genes were detected in 7 isolates belonging to serogroup 19. Absence of co-resistance was observed most frequently in serogroup 14 (66.7%). Co-resistance with penicillin G, tetracycline, and trimethoprim-sulfamethoxazole was associated with serogroup 19 (36.8%). Two isolates (0.8%) were resistant to telithromycin. Conclusion. The frequency of macrolide resistance mechanisms in the Canary Islands is different from that observed in the rest of Spain, particularly in Lanzarote, where 80% of isolates harbored the mefA/E gene and belonged to serogroup 14 (AU)
