AUTHOR=Pinto Tatiana C. A. , Costa Natália S. , Pina Sandrine E. C. M. , Souza Aline R. V. , Oliveira Laura M. A. , Moura Camille A. B. , Kegele Fabíola C. O. , Merquior Vânia L. C. , Botelho Ana Caroline N. , Peralta José M. , Teixeira Lúcia M. TITLE=Virulence-Associated Characteristics of Serotype 14 and Serogroup 9 Streptococcus pneumoniae Clones Circulating in Brazil: Association of Penicillin Non-susceptibility With Transparent Colony Phenotype Variants JOURNAL=Frontiers in Microbiology VOLUME=Volume 11 - 2020 YEAR=2020 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.02009 DOI=10.3389/fmicb.2020.02009 ISSN=1664-302X ABSTRACT=Streptococcus pneumoniae remains as a major agent of invasive diseases, especially in children and the elderly. The presence of pneumococcal capsule, pneumococcal surface protein A (PspA) and pilus type 1 (PI-1), and the ability of colony phase variation are assumed to play important roles in the virulence potential of this microorganism. Differences in the capsular polysaccharide allow the characterization of more than 90 pneumococcal serotypes; among them, serotype 14 and serogroup 9 stand out due to their prevalence in the pre-PCV era and frequent association with penicillin-nonsusceptibility. Here we investigated the distribution of PI-1 and pspA genes and colony phase variants among 315 S. pneumoniae isolates belonging to serotype 14 and serogroup 9 recovered over 20 years in Brazil, and correlated these characteristics with penicillin susceptibility and genotype as determined by MLST. All strains were shown to carry pspA genes, being those of family 2 (pspA2) the most common; and nearly half of the strains harbored P1-1 genes. pspA gene family and presence of PI-1 genes were conserved features among strains belonging to a given clone. A trend for increasing occurrence of pspA2 and PI-1 genes over the period of investigation was observed, and it coincided with the dissemination of CC156 (Spain9V-3) clone in Brazil, suggesting a role for these virulence attributes in the establishment and persistence of this successful clone. Opaque variant was the colony phenotype most frequently observed regardless of clonal type. On the other hand, the transparent variant was more commonly associated with penicillin-nonsusceptible pneumococci (PNSP) and with strains presenting evidence of recombination events involving the genes coding for polysaccharide capsule and PspA, suggesting that pneumococcal transparent variants may present a higher ability to acquire exogenous DNA. The results bring to light new information about the virulence potentials of serotype 14 and serogroup 9 S. pneumoniae isolates representing the major clones that have been associated with the emergence and dissemination of antimicrobial resistance in our setting since the late 1980’s.