[Macrolide-resistant Streptococcus pneumoniae on the islands of Gran Canaria and Lanzarote (Spain): molecular mechanisms and serogroup relationships].
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.


CONCLUSIONS
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.
Artiles
Fernando
F
Servicio de Microbiología. Hospital Universitario de Gran Canaria. Las Palmas de Gran Canaria. España.
Horcajada-Herrera
Iballa
I
Noguera-Catalán
Javier
J
Alamo-Antúnez
Isabel
I
Bordes-Benítez
Ana
A
Lafarga-Capuz
Bernardo
B
D000293:Adolescent; D000328:Adult; D001266:Atlantic Islands / Q000453:epidemiology; D001426:Bacterial Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D018942:Macrolides / Q000494:pharmacology*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D010641:Phenotype; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D012703:Serotyping; D013030:Spain / Q000453:epidemiology; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification
D001426:Bacterial Proteins; D018942:Macrolides; C117866:MefA protein, Streptococcus; C431304:MefE protein, Streptococcus pneumoniae; D008565:Membrane Proteins