Characterization of Streptococcus pneumoniae invasive serotype 19A isolates from Argentina (1993-2014).

Characterization of Streptococcus pneumoniae invasive serotype 19A isolates from Argentina (1993-2014). Vaccine. 2017 Jul 20;: Authors: Gagetti P, Faccone D, Reijtman V, Fossati S, Rodriguez M, Veliz O, Ceriana P, Regueira M, SIREVA II Group, Corso A Abstract The aim of this study was to characterize Streptococcus pneumoniae serotype 19A isolates causing invasive pneumococcal disease in children, collected in Argentina between 1993 and 2014. A total of 176 isolates serotype 19A were analyzed. There was an increase in the proportion of serotype 19A isolates from 3% in 1993 to 6% in 2011, prior to the introduction of PCV13 in 2012, and from 2012 to 2014 its proportion gradually decreased. Penicillin resistance among serotype 19A isolates throughout the study period was 65.9%, but a significant increase was observed from 0% in 1993 to 87.5% in 2014. Genetic relationship of the isolates was determined by PFGE and selected strains were studied by MLST. Most of the isolates belonged to two clonal types: A (54.5%) and B (11.4%). Isolates of clonal type A were ST1131, a single locus variant of ST172 and accounted for 54% of the total collection. They were detected for the first time in our country in 1997 and most of them (93%) were penicillin non susceptible. Isolates of clonal type B were ST8121, a single locus variant of ST199, and were mainly susceptible to penicillin. These two clonal types are still in circulation and appear to be resp...
Source: Vaccine - Category: Allergy & Immunology Authors: Tags: Vaccine Source Type: research