Objective: To study the characteristics and the evolution through time of a single Streptococcus pneumoniae multidrug-resistant international clone.
Methods: From 1981 to 2002, the presence of the multidrug-resistant Spain14-5 clone was studied among the 4201 S. pneumoniae isolated in Gipuzkoa (northern Spain).
Results: Overall, 93 isolates belonging to the Spain14-5 clone were identified. The first isolate of this clone was detected in 1981 and was already resistant to beta-lactams, erythromycin, clindamycin and chloramphenicol. The reference strain from the international collection for this clone was susceptible to macrolides and lincosamides whereas most of the isolates studied, including the first isolate detected in 1981, were resistant to macrolides and had the erm(B) gene encoding macrolide resistance.
Conclusions: The clone was genetically stable through time, was multiresistant since its inception and has recently become highly resistant to fluoroquinolones. The characteristic antibiotic resistance pattern of this clone should include erythromycin resistance.