Serotypes and genotypes of invasive Streptococcus pneumoniae before and after PCV10 implementation in southern Brazil.

Juliana Caierão,Cícero Dias,Fernando Hayashi Sant’anna,Pedro Alves d’Azevedo,Paulina Hawkins,Lesley McGee,Gabriela Rosa da Cunha,Herminia de Lencastre

doi:10.1371/journal.pone.0111129

Abstract

To reduce the burden of pneumococcal diseases, different formulations of pneumococcal conjugate vaccines (PCV) have been introduced in many countries. In Brazil, PCV10 has been available since 2010. We aimed to analyze the serotype and genetic composition of invasive pneumococci from Brazil in pre- and post- vaccination periods (2007–2012). Antibiotic susceptibility was determined and genotypes of macrolide and fluoroquinolone resistance were characterized. The genotypes of isolates of the most frequent serotypes were determined by multilocus sequence typing. The study included 325 isolates, which were primarily recovered from blood. The most common serotypes recovered were 14, 3, 4, 23F, 7F, 9V, 12F, 20, 19F, 8, 19A, and 5. Thirty-eight pneumococci (11.7%) were from children ≤5 years old. Considering the overall population, PCV10 and PCV13 serotype coverage was 50.1% and 64.9%, respectively. During the pre-vaccine period, isolates with serotypes belonging to the PVC10 represented 51.5% (100/194), whereas in the post vaccine they represented 48.0% (63/131). PCV13 serotypes represented 67.5% (131/194) and 59.2% (77/131) of total for pre- and post-vaccination periods, respectively. Seventy different sequence types [STs] were found, accounting for 9 clonal complexes [CCs] and 45 singletons. Eight STs (156, 180, 218, 8889, 53, 191, 770, and 4967) represented the majority (51.5%) of isolates. Fifty STs were associated with the pre-vaccination period (27 exclusive) and 43 (20 exclusive) with the post-vaccination period; 23 STs were identified in both periods. Some serotypes were particularly clonal (7F, 8, 12F, 20). Non-susceptibility to penicillin was associated with serotype 19A, CC320. Erythromycin resistance was heterogeneous when considering serotype and ST. A single serotype 23F (ST4967) isolate was resistant to levofloxacin. Continued surveillance is required to determine vaccine impact and to monitor changes in pneumococcal population biology post-PCV10 introduction in Brazil.

Highlights

Infections associated with Streptococcus pneumoniae are a global public health problem
A total of 325 non-duplicate pneumococci recovered from patients with Invasive pneumococcal diseases (IPD) were included in the study
S. pneumoniae infections were mostly associated with the following serotypes: 14 (11.4%), 3 (8.3%), 4 (7.1%), 23F (6.1%), 7F (5.8%), 9V (4.9%), 12F (4.9%), 20 (4.9%), 19F (4%), 8 (4%), 19A (3.4%) and 5 (3.4%)

Summary

Introduction

Infections associated with Streptococcus pneumoniae are a global public health problem. Invasive pneumococcal diseases (IPD), such as meningitis and bacteremia, are especially associated with high morbidity and mortality [1]. About 3,600 cases of meningitis, 14,000 cases of bacteremia, and between 200,000 and 300,000 cases of pneumonia associated with pneumococci occur annually in Latin America [2]. In Brazil, from 2000 to 2008, pneumococcal meningitis represented 11% of all bacterial meningitis, with an incidence of 9.5 cases/100,000 inhabitants in patients less than one year of age. Official data from Brazil demonstrate that in the same period 7,129,291 hospitalizations were associated with complications of community-acquired pneumonia where S. pneumoniae was the major etiological agent Andrade and co-workers estimated the incidence of IPD in children less than three years of age from Brazil (2007– 2009) at 57.5/100,000 inhabitants [3]

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