PENICILLIN-RESISTANT STREPTOCOCCUS-PNEUMONIAE IN ARGENTINA - FREQUENTOCCURRENCE OF AN INTERNATIONALLY SPREAD SEROTYPE-14 CLONE

Six Latin-American countries participated in an epidemiological survei llance study conducted by the Pan American Health Organization in orde r to determine the relative prevalence of capsular types and antimicro bial resistance patterns of Streptococcus pneumoniae (SPN) causing inv asive infections in children <5 years of age, In Argentina, the incide nce of penicillin resistance (PR) was 24.4%, and it was significantly associated with serotype 14 (p < 0.001), The chromosomal DNA of 56 of those SPN isolates, 39 PR and 17 susceptible, was digested with SmaI a nd resolved by PFGE, Eighty-two percent (32/39) of the PR isolates sha red characteristics with the widely spread International Spanish/Frenc h clone (clone B), All members of clone B except one expressed serotyp e 14, with the exception of one isolate that expressed serotype 19F an d probably resulted from an in vivo capsular transformation event. Onl y a single isolate shared features with the 23F International Spanish/ USA clone (clone A). The 17 penicillin-susceptible (PS) SPN isolates p resented an enormous degree of variation in the chromosomal background , expressing 12 serotypes and 13 PFGE patterns. The data suggest that over 80% of the SPN-PR isolates in Argentina were imported, and this c onfirms the importance of the geographic spread of SPN clones in South America.