The apparent importation of penicillin-resistant capsular type 14 Spanish/French clone of Streptococcus pneumoniae into Uruguay in the early 1990s

Abstract

Since 1987, Streptococcus pneumoniae (SPN) has been monitored in pediatric and adult populations. In 1994, the SIREVA/PAHO surveillance allowed the assessment of a dramatic increase of penicillin resistance, mainly associated to SPN type 14 also resistance to trimethoprim/sulfamethoxazole. To determine the genetic relatedness of the resistant isolates, analysis of SmaI digests of 61 isolates was performed by pulsed field gel electrophoresis (PFGE). Twelve different profiles were identified. The type 14 resistant SPN (n = 47) displayed a common B pattern, with 15 genetically related subtypes (1-6 bands of difference), with B1 the predominant one (51%). One of the subtypes (B12) was indistinguishable from a French isolate (M13P). This strain represented a South European clone, identified in the late 1980s, that also included serogroup 9 isolates. The type 23F isolates (n = 3) were identical with a representative strain of the well-characterized intercontinental type 23F clone. Neither the type 14 penicillin-susceptible (n = 4) nor the resistant SPN of other serotypes (n = 10) belonged to the B pattern. In summary, the results suggest that the dramatic increase of penicillin resistance in Uruguay depends on the introduction and spread of a type 14 clone, apparently imported from the south of Europe. Follow-up of this phenomenon is mandatory from the point of view of epidemiology and is also a priority for biologic research.