Description of optochin-resistant Streptococcus pneumoniae due to an uncommon mutation in the atpA gene and comparison with previously identified atpC mutants from Brazil.

Optochin susceptibility testing is a major assay used for presumptive identification of Streptococcus pneumoniae. Still, atypical optochin-resistant (Opt) pneumococci have been reported and this phenotype has been attributed to nucleotide substitutions in the genes coding for the FFATPase. While substitutions in the atpC gene (c-subunit of ATPase) are more common and better characterized, data on mutations in the atpA (a-subunit) are still limited.

Virulence-Associated Characteristics of Serotype 14 and Serogroup 9 Clones Circulating in Brazil: Association of Penicillin Non-susceptibility With Transparent Colony Phenotype Variants.

remains 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- pneumococcal conjugate vaccine era and frequent association with penicillin non-susceptibility.

Phenotypic and molecular characterization of optochin-resistant Streptococcus pneumoniae isolates from Brazil, with description of five novel mutations in the ATPC gene.

Optochin (Opt) susceptibility is used largely for the identification of Streptococcus pneumoniae in diagnostic laboratories. Opt-resistant (Opt(r)) S. pneumoniae isolates have been reported, however, indicating the potential for misidentification of this important pathogen.