Molecular Characterization of Predominant Serotypes, Drug Resistance, and Virulence Genes of Streptococcus pneumoniae Isolates From East China

Abstract

Streptococcus pneumoniae is a common diplococcus pathogen found worldwide. The characterization of predominant serotypes, drug resistance, and virulence genes of S. pneumoniae isolates prevailing in different areas and countries is clinically important for choice of antibiotics and improvement of vaccines. In this study, pneumonia (78.7%) and meningitis (37.0%) were the predominant diseases observed in the 282 (children) and 27 (adults) S. pneumoniae-infected patients (p < 0.05) from seven hospitals in different areas of East China. Of the 309 pneumococcal isolates, 90.3% were classified by PCR into 15 serotypes, with serotypes 19F (27.2%) and the 6A/B (19.1%) being most predominant (p < 0.05). Importantly, serotypes 15A and 15B/C combined for a total of 10.4% of the isolates, but these serotypes are not included in the 13-valent pneumococcal capsule conjugate vaccine used in China. Antimicrobial susceptibility analysis by the E-test showed that >95% of the 309 pneumococcal isolates were susceptible to moxifloxacin and levofloxacin, as well as 18.4, 85.8, and 81.6% of the isolates displayed susceptibility to penicillin, cefotaxime, and imipenem, respectively. A significant correlation between the prevalence of predominant serotypes and their penicillin resistance was observed (p < 0.05). In particular, >95% of all the pneumococcal isolates showed resistance to erythromycin and azithromycin. Of the nine detected virulence genes, the lytA, ply, hysA, and nanA were the most common with 95–100% positive rates in the 309 pneumococcal isolates, while the pavA and psaA genes displayed a significant correlation with pneumococcal bacteremia and meningitis (p < 0.05). Overall, our data suggested that the predominant serotypes, drug resistance, and virulence genes of the S. pneumoniae isolates prevailing in East China are distinct from those observed in other areas of China and adjacent countries.

Molecular characterization of invasive Streptococcus pneumoniae clinical isolates from a tertiary children’s hospital in eastern China

“…The distribution of serotypes varies with geographic region, age, infection type, and time. In this study, the most prevalent distribution of serotypes among invasive S. pneumoniae -infected children in Nanjing was 19F, 14, 6A, 23F, 19A, and 6B, which were similar to other geographic regions of China, such as southwest China (19F, 19A, 6B, 6A, and 14), East China (19F, 6A/B, 23F, 14, and 15A), Shanghai (19F, 19A, 6A, 14, and 6B), and Beijing (19F, 19A, 23F, 14, and 6A) ( 15 , 16 , 21 , 22 ). Conversely, there were differences in the serotype distribution in international regions, such as Africa (28F, 6A, 11A, 3, and 7C) and Egypt (1, 6ABC, 19F, 5, and 18ABC) ( 3 , 23 , 24 ).…”

Antimicrobial susceptibility and serotype distribution of Streptococcus pneumoniae isolates among children in Suzhou, China

“…Serotype distribution among different countries is remarkably different. In this study, the most prevalent pneumococcal serotype was 19F, and similar findings have been observed in most domestic reports in recent years ( 14 , 15 ). This finding differs from previous studies conducted in other countries, including the USA (35B, 3, 23A) and Japan (12F, 3, 23A, 19A) ( 16 , 17 ).…”

<strong></strong>Effect of Erythromycin Residuals in Food on the Development of Resistance in <em>Streptococcus pneumoniae</em>: An <em>In Vivo</em> Study in <em>Galleria mellonella</em>

“…The S. pneumoniae isolate used for this experiment had the following virulence genes: cbpD, cbpG, cps4A, cps4B, cps4C, cps4D, hysA, lytA, lytB, lytC, nanB, pavA, pce, pfbA, ply, psaA that encode products important for adherence, colonization, invasion, and survival [35][36][37][38][39][40][41][42][43][44]. Both intrinsic and acquired mechanisms affect susceptibility to a large variety of antibiotics [45].…”