Expansion of the multidrug-resistant clonal complex 320 among invasive Streptococcus pneumoniae snerotype 19A after the introduction of a ten-valent pneumococcal conjugate vaccine in Brazil

Author(s)

Cassiolato, Ana Paula ^[1] ; Grassi Almeida, Samanta Cristine ^[1] ; Andrade, Ana Lucia ^[2] ; Minamisava, Ruth ^[3] ; de Cunto Brandileone, Maria Cristina ^[1]

Affiliation

^[1] Adolfo Lutz Inst, Ctr Bacteriol, Natl Lab Meningitis & Pneumococcal Infect, Sao Paulo, SP - Brazil

^[2] Univ Fed Goias, Inst Trop Pathol & Publ Hlth, Goiania, Go - Brazil

^[3] Univ Fed Goias, Fac Nursing, Goiania, Go - Brazil

• Document type: Journal article
• Source: PLoS One; v. 13, n. 11 NOV 29 2018.
• Web of Science Citations: 8

Abstract

Background In 2010, a ten-valent pneumococcal conjugate vaccine (PCV10) was introduced in the routine infant national immunization program in Brazil. Invasive pneumococcal disease (IPD) caused by serotype 19A (Spn19A) increased after the introduction of PCVs in several countries. We compared the frequency, antimicrobial resistance and molecular patterns of invasive Spn19A strains before and after PCV10 introduction in Brazil using data from the national laboratory-based surveillance. Methods We analyzed invasive Spn19A strains isolated from 2005-2009 (pre-PCV10 period), 2011-2015 and 2016-2017 (post-PCV10 periods). Antimicrobial susceptibility was performed for all Spn19A strains, and multilocus sequence typing (MLST) was performed for strains isolated in the age groups < 5 years and >= 50 years. Results Among the study period, a total of 9,852 invasive Spn strains were analyzed, and 673 (6.8%) belonged to serotype 19A. Overall, the proportion of Spn19A among the total number of IPD strains increased from 2.8% in 2005-2009 to 7.0% and 16.4% in 2011-2015 and 2016-2017, respectively. The relative increase in Spn19A was observed especially in children < 5 years old (2005-2009: 3.2%; 2011-2015: 15.5%; 2016-2017: 31.2%). The percentage of penicillin resistance (MIC 2.0-4.0 mu g/mL), erythromycin resistance and multidrug resistance (MDR) increased after PCV10 introduction due to the expansion of the MDR clonal complex CC320 (2005-2009: 8.6%; 2011-2015: 56.1%; 2016-2017: 66.5%). Conclusion We observed an expansion of MDR-CC320 among invasive Spn19A strains after PCV10 introduction in Brazil, probably related to a combination of factors, such as vaccination and antimicrobial pressure. Continued surveillance of Spn19A strains is necessary to monitor the sustainability of this clonal complex in the Brazilian population. (AU)

• FAPESP's process: 13/03968-6 - Importance of Streptococcus pneumoniae serotype 19A isolated from carriers and invasive disease before and after introduction of conjugate vaccine 10-valente in Brazil
• Grantee: Ana Paula Cassiolato
• Support Opportunities: Scholarships in Brazil - Master