Bacteriological characteristics and changes of Streptococcus pneumoniae serotype 35B after vaccine implementation in Japan.
Epidemiol Infect
; 152: e114, 2024 Oct 04.
Article
in En
| MEDLINE
| ID: mdl-39363586
ABSTRACT
Streptococcus pneumoniae serotype 35B, a non-vaccine type, is a major contributor to the increase in pneumococcal infection post-vaccination. We aimed to understand the mechanism of its spread by characterizing 35B. The serotype, type 1 pilus (T1P) positivity, and antimicrobial susceptibility of 319 isolates in 2018-2022 were analysed and compared with those of isolates in 2014-2017 to find the changes. 35B accounted for 40 (12.5%) isolates. T1P positivity was notably higher in 35B (87.5%) than in the other serotypes. To confirm the role of T1P, an adhesion factor, we compared adherence to A549 cells between T1P-positive 35B isolates and their T1P-deficient mutants, showing contribution of T1P to adherence. Penicillin-non-susceptible rate of 35B was 87.5%, and meropenem-resistant 35B rate was 35.0%, which increased from 14.5% of 2014-2017 (p = 0.009). Multilocus sequence typing was performed in 35B strains. Prevalence of clonal complex 558, harbouring T1P and exhibiting multidrug non-susceptibility, suggested the advantages of 35B in attachment and survival in the host. The emergence of ST156 isolates, T1P-positive and non-susceptible to ß-lactams, has raised concern about expansion in Japan. The increase of serotype 35B in pneumococcal diseases might have occurred due to its predominant colonizing ability after the elimination of the vaccine-serotypes.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Pneumococcal Infections
/
Streptococcus pneumoniae
/
Pneumococcal Vaccines
/
Serogroup
Limits:
Adolescent
/
Adult
/
Aged
/
Aged80
/
Child
/
Child, preschool
/
Female
/
Humans
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Infant
/
Male
Country/Region as subject:
Asia
Language:
En
Journal:
Epidemiol Infect
Journal subject:
DOENCAS TRANSMISSIVEIS
/
EPIDEMIOLOGIA
Year:
2024
Document type:
Article
Affiliation country:
Japan
Country of publication:
United kingdom