Clonal lineages and antimicrobial resistance of nonencapsulated Streptococcus pneumoniae in the post-pneumococcal conjugate vaccine era in Japan

Abstract

The emergence and spread of nonencapsulated Streptococcus pneumoniae (NESp) is a public health concern in the post-pneumococcal conjugate vaccine era. We analyzed the prevalence, molecular characteristics, and antimicrobial resistance of NESp responsible for noninvasive infections in northern Japan. Methods: NESp isolates were identified using molecular and phenotypical methods among 4463 S. pneumoniae isolates from noninvasive infection cases during 4 study periods between January 2011 and January 2019. NESp isolates were analyzed for antimicrobial susceptibility, genotype, and virulenceassociated genes.Results: Seventy-one NESp isolates were identified (1.6% of total clinical isolates) and assigned to the null capsule clade (NCC)1 (pspK+) (94.4%) or NCC2 (aliC+/aliD+) (5.6%). The dominant sequence types (STs) were ST7502 (23.9%), ST4845 (19.7%), ST16214 (11.3%), ST11379 (9.9%), and ST7786 (7.0%). These 5 dominant STs and all 7 novel STs were related to the sporadic NESp lineage ST1106 or PMEN clone Denmark 14 -ST230. High non-susceptibility rates of NESp were observed for trimethoprim-sulfamethoxazole, erythromycin, and tetracycline (>92.9%), and multidrug resistance was observed in 88.7% of the NESp isolates, including all ST7502, ST4845, and ST11379 isolates. Conclusions:The study revealed that the dominant clonal groups of NESp were associated with a high prevalence of non-susceptibility to antimicrobials in northern Japan.

Serotype replacement and an increase in non-encapsulated isolates among community-acquired infections of Streptococcus pneumoniae during post-vaccine era in Japan

“…Phylogeny suggests that NCC3 is linked closely with Streptococcus pseudopneumoniae and Streptococcus mitis [8] . The antimicrobial susceptibility of NCC 1, 2, and 3 was similar to that of other serotypes, but the NCC clades tended to be less susceptible to penicillin G, similar to the findings of a previous report [28] ; however, the prevalence of low susceptibility was less noticeable when compared with serotypes 35B, 15A/F, and 23A.…”

A Review of the Impact of Streptococcal Infections and Antimicrobial Resistance on Human Health

“…In the period 2000-2015, PRSPs were found in a low range of 3.8 to 14.3% in the USA and Turkey [29,31]. In Poland, 45% of PRSPs were reported [21], and in Japan, it ranged from 33.8% and 67% [25,34]. During the same period, penicillin non-susceptibility in causative agents of invasive pneumococcal disease (IPD) was found to be around 20% in Spain and Croatia [28,30], 42.8% in Brazil [33], and 32% in China [35].…”

“…There is an increasing resistance to alternative antibiotics of penicillins such as macrolides and lincosamides among the Streptococcus genus, especially in Asia [6,34,35,47]. Macrolide resistance (MR) is the most common type of resistance among pneumococci and beta-streptococci groups A and B. Macrolides are commonly used to treat respiratory tract infections in both children and adults and were used empirically during the COVID-19 pandemic [83,84].…”

Invasive Pneumococcal Diseases in Korean Adults After the Introduction of Pneumococcal Vaccine into the National Immunization Program

“…In particular, during the 2019 - 2021 study period, 32.5% of invasive pneumococcal isolates were not susceptible to ceftriaxone, and during the 2013 - 2015 period, 18.7% of IPD isolates were not susceptible to ceftriaxone, but in most countries reported at a low rate. <10%: Japan (8.4%, 2011 - 2019), South Africa (8.0%, 2003 - 2010), United States (8.7%, 2010 - 2011) [ 56 57 ]. Penicillin resistance does not appear to affect survival, but there may be worse outcomes in patients with cephalosporin resistance.…”