Population Structure of Streptococcus pneumoniae Causing Invasive Disease in Adults in Portugal before PCV13 Availability for Adults: 2008-2011

Abstract

Among the 1660 isolates recovered from invasive pneumococcal disease (IPD) in adults (> = 18 yrs) in 2008–2011, a random sample of ≥50% of each serotype (n = 871) was chosen for MLST analysis and evaluation for the presence and type of pilus islands (PIs). The genetic diversity was high with 206 different sequence types (STs) detected, but it varied significantly between serotypes. The different STs represented 80 clonal complexes (CCs) according to goeBURST with the six more frequent accounting for more than half (50.6%) of the isolates—CC156 (serotypes 14, 9V and 23F), CC191 (serotype 7F), CC180 (serotype 3), CC306 (serotype 1), CC62 (serotypes 8 and 11A) and CC230 (serotype 19A). Most of the isolates (n = 587, 67.3%) were related to 29 Pneumococcal Molecular Epidemiology Network recognized clones. The overall proportion of isolates positive for any of the PIs was small (31.9%) and declined gradually during the study period (26.6% in 2011), mostly due to the significant decline of serotype 1 which is associated with PI-2. The changes in serotypes that occurred in adult IPD after the introduction of the seven-valent pneumococcal conjugate vaccine (PCV7) for children were mostly due to the expansion of previously circulating clones, while capsular switching was infrequent and not related to vaccine use. The reduction of IPD caused by PCV7 serotypes in the years following PCV7 implementation did not result in a decline of antimicrobial resistance in part due to the selection of resistant genotypes among serotypes 14 and 19A.

Streptococcus pneumoniae Serotype 3 in Mexico (1994 to 2017): Decrease of the Unusual Clonal Complex 4909 Lineage following PCV13 Introduction

“…The CC260 lineage present in Mexico was also present as a minor serotype 3 lineage in other countries (14,27). In line with previous observations, this lineage was mostly susceptible to all antimicrobials.…”

“…CC180 was previously found in adults and children, in carriage, and causing a range of infections, from otitis media to meningitis, a diversity also reflected in the Mexican isolates. In contrast to what was found in Japan (15) but similar to what was found elsewhere (5,18,26,27), CC180 isolates in Mexico were mostly susceptible to all antimicrobials tested. A genomic analysis revealed three distinct sublineages of CC180 isolates associated with distinct antimicrobial resistance patterns (25), raising the possibility that different sublineages may be dominant in different geographic regions.…”

“…Although, to date, there is limited evidence of a differential effect of PCV13 in different lineages expressing the same vaccine serotype, the decrease of CC4909 in the post-PCV13 period deserves closer scrutiny. Having said this, data from Portugal, also using MLST to identify lineages, revealed that both CC260 and CC458, which were circulating together with CC180, declined as a cause of adult IPD even before PCV13 use in children (27), suggesting that temporal trends may also play a major role in the dynamics of serotype 3 lineages. The persistence of CC4909 in Mexico and its apparent restricted geographic dissemination are puzzling.…”

Overview of pneumococcal serotypes and genotypes causing diseases in patients with chronic obstructive pulmonary disease in a Spanish hospital between 2013 and 2016

“… 10 The continuous increase of CC386 (serotype 6C) is yet another important issue, because this multidrug-resistant clone has resistance to macrolides and lincosamides and has been detected in neighboring European countries such as France or Portugal as a cause of pneumococcal disease, especially in adults. 29 – 31 It is possible that the increased use of azithromycin to treat patients with advanced COPD pathology, because of their possible anti-inflammatory activity, could have contributed to the high prevalence of this macrolide- and multidrug-resistant clone. 32 …”

Association Between Pneumococcal Surface Protein A Family and Genetic/Antimicrobial Resistance Traits of Non-Invasive Pneumococcal Isolates from Adults in Northern Japan

“…The serotype 3/ST180 lineage was found to be predominant globally, 36,37 and was documented as a common lineage in adults. [38][39][40] This serotype was mainly isolated from IPD adult patients from pre-PCV to post-PCV period. 41 In Greece, serotype 3 accounted for 33% in isolates obtained from PCV13vaccinated children, 42 while in Portugal its prevalence in children did not show a significant change.…”