AUTHOR=Miao Chenglin , Yan Ziyi , Chen Chunmei , Kuang Linghan , Ao Keping , Li Yingying , Li Jialu , Huang Xiaocui , Zhu Xinghua , Zhao Yijia , Cui Yali , Jiang Yongmei , Xie Yi 

TITLE=Serotype, antibiotic susceptibility and whole-genome characterization of Streptococcus pneumoniae in all age groups living in Southwest China during 2018–2022

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1342839

DOI=10.3389/fmicb.2024.1342839

ISSN=1664-302X

ABSTRACT=<sec id="sec1"><title>Background</title><p><italic>Streptococcus pneumoniae</italic> is a common pathogen that colonizes the human upper respiratory tract, causing high morbidity and mortality worldwide. This study aimed to investigate the prevalence status of <italic>S. pneumoniae</italic> isolated from patients of all ages in Southwest China, including serotype, antibiotic susceptibility and other molecular characteristics, to provide a basis for clinical antibiotic usage and vaccine development.</p></sec><sec id="sec2"><title>Methods</title><p>This study was conducted from January 2018 to March 2022 at West China Hospital, West China Second University Hospital, First People’s Hospital of Longquanyi District (West China Longquan Hospital), Meishan Women and Children’s Hospital (Alliance Hospital of West China Second University Hospital) and Chengdu Jinjiang Hospital for Women and Children Health. Demographic and clinical characteristics of 263 pneumococcal disease (PD) all-age patients were collected and analyzed. The serotypes, sequence types (STs), and antibiotic resistance of the strains were determined by next-generation sequencing, sequence analysis and the microdilution broth method.</p></sec><sec id="sec3"><title>Results</title><p>The most common pneumococcal serotypes were 19F (17.87%), 19A (11.41%), 3 (8.75%), 23F (6.46%) and 6A (5.70%). Coverage rates for PCV10, PCV13, PCV15, PCV20 and PCV24 were 36.12, 61.98, 61.98, 63.12 and 64.26%, respectively. Prevalent STs were ST271 (12.55%), ST320 (11.79%), ST90 (4.18%), ST876 (4.18%) and ST11972 (3.42%). Penicillin-resistant <italic>S. pneumoniae</italic> (PRSP) accounted for 82.35 and 1.22% of meningitis and nonmeningitis PD cases, respectively. Resistance genes <italic>msrD</italic> (32.7%), <italic>mefA</italic> (32.7%), <italic>ermB</italic> (95.8%), <italic>tetM</italic> (97.3%) and <italic>catTC</italic> (7.6%) were found among 263 isolates. Most isolates showed high resistance to erythromycin (96.96%) and tetracycline (79.85%), with more than half being resistant to SXT (58.94%). A few isolates were resistant to AMX (9.89%), CTX (11.03%), MEN (9.13%), OFX (1.14%), LVX (1.14%) and MXF (0.38%). All isolates were susceptible to vancomycin and linezolid.</p></sec><sec id="sec4"><title>Conclusion</title><p>Our study provides reliable information, including the prevalence, molecular characterization and antimicrobial resistance of <italic>S. pneumoniae</italic> isolates causing pneumococcal diseases in Southwest China. The findings contribute to informed and clinical policy decisions for prevention and treatment.</p></sec>