| Congresso Brasileiro de Microbiologia 2023 | Resumo: 151-2 | ||||
Resumo:The 10-valent pneumococcal conjugate vaccine (PCV10) has been available for childhood immunization nationwide and free of charge since 2010 in Brazil. We have been systematically conducting cross-sectional studies in children in Niterói since 2010, where we detected the emergence and predominance of multidrug resistant (MDR) serotype 6C four years after PCV10 introduction. Serotype 19A has also been detected in colonization and it is the major serotype associated with invasive pneumococcal diseases (IPD) in Brazil. Thus, we conducted a cross-sectional study to evaluate the antimicrobial resistance profile and genetic lineages of serotypes 6C and 19A associated with carriage in children 9 years after PCV10 introduction in Niterói, RJ. Between September and December 2019, we recruited 602 children who attended two private clinics (n=270) and two public clinics (n=332) in Niterói. Isolates were detected by culture after a broth enrichment step and capsular types were determined by multiplex PCR and/or cpsB sequencing. Serotype 6C and 19A isolates were, then, subjected to antimicrobial susceptibility testing and multilocus sequencing typing (MLST). We identified 105 (17.4%) pneumococcal carriers and we recovered one isolate from each carrier. Serotype 6C made up 15.2% (n=16) of the 105 isolates and 10 (62.5%) of the 16 serotype 6C isolates belonged to ST386, mostly showing resistance to erythromycin (ERY), clindamycin (CLI), penicillin (PEN), and tetracycline. Serotype 6C isolates had MICs to PEN ranging from 0.12 µg/mL to 1.0 µg/mL and ERY > 256 µg/mL, mostly having the erm(B) gene. Serotype 19A isolates comprised 7.6% (n=8) and all but one were MDR, mostly with resistance to ERY, CLI, PEN, and sulfamethoxazole-trimethoprim. One isolate was susceptible for all drugs tested. Among the seven MDR 19A isolates, PEN MICs ranged from 2.0 µg/mL to 4.0 µg/mL. Six (75%) of the eight serotype 19A isolates had ERY MIC > 256 µg/mL and both the erm(B) and mef(A/E) genes. Most serotype 19A isolates belonged to clonal complex (CC) 320. After long-term childhood immunization with PCV10 in Brazil, carriage isolates of serotypes 6C and 19A are frequently associated with multidrug resistance and mostly belong to specific lineages. Expanding vaccination with the 13-valent PCV might help control transmission and IPD with these emerging MDR serotypes. Palavras-chave: Streptococcus pneumoniae, serotypes, antimicrobial resistance, genetic lineage, pneumococcal conjugate vaccines Agência de fomento:FAPERJ – Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro, CNPq – Conselho Nacional de Desenvolvimento Científico e Tecnológico, CAPES – Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, PDPA - Prefeitura de Niterói-RJ | |||||