Molecular characterization of non-vaccine Streptococcus pneumoniae serotypes 11A, 15 B/C and 23A recovered from invasive isolates in Colombia

Abstract

Introducción. En Colombia se recolectaron 192 aislamientos invasivos de Streptococcus pneumoniae de los serotipos 11A, 15B/C y 23A (no incluidos en las vacunas conjugadas) entre 1994 y 2014, como parte de las actividades del Sistema de Redes de Vigilancia de los Agentes Responsables de Neumonías y Meningitis Bacterianas (SIREVA II).Objetivo. Determinar las características moleculares de aislamientos invasivos de los serotipos 11A, 15B/C y 23A de S. pneumoniae recolectados en Colombia entre 1994 y 2014. Materiales y métodos. La caracterización molecular de los aislamientos se hizo mediante electroforesis en gel de campo pulsado (Pulse-Field Gel Electrophoresis, PFGE) y por tipificación de secuencias multilocus (Multilocus Sequence Typing, MLST).Resultados. El serotipo 11A mostró un grupo clonal representado por el ST62, en tanto que el serotipo 15B/C se distribuyó en tres grupos asociados con los clones Netherlands15B-37 ST199 (28,75 %), ST8495 (18,75 %) y SLV (variante en un solo locus) de ST193 (21,25 %). Los aislamientos con serotipo 23A se agruparon en tres grupos clonales; 70,21 % de ellos estaban estrechamente relacionados con el ST42, 17,02 % con el Colombia23F-ST338, y 6,38 % con el Netherlands15B-37 ST199.Conclusión. Los clones Colombia23F-ST338 y Netherlands15B-ST199 encontrados en este estudio abarcaron más serotipos de los reportados previamente por otros autores, incluido el serotipo 23A. Estos análisis revelan la importancia de la conmutación (switching) capsular en la expansión de clones exitosos entre los serotipos no vacunales como causa de enfermedad invasiva neumocócica.

Polysaccharide Capsule Serotype and Antibiotic Susceptibility Pattern of Streptococcus pneumoniae Clinical Isolates in Bali

“…19 Several studies have also identified non-vaccine strains, namely serotype 15B/C, in France, Colombia, Thailand, and Indonesia (Lombok, Jakarta, and Semarang). [5][6][7][20][21][22] Interestingly, serotype 15B/C is not covered by PCV13 or PPSV23. Serotype 15B/C has potential as a vaccine candidate, considering that cases of invasive pneumonia caused by this serotype, including serotype 15B/C, are increasing in several countries such as France, Colombia, Thailand, and Indonesia.…”

“…[20][21][22] The introduction and use of unconjugated versus conjugated pneumococcal polysaccharide vaccines have reduced the proportion of pneumococcal infections caused by S. pneumoniae. Those two years of age or older are protected against invasive illness caused by the 23 capsular serotypes included in the PPSV23 vaccination because of the development of a vaccine called PPSV23.…”

Pneumococcal Burden in Hospitalized Adults in Bogotá, Colombia.

“…Importantly, only 1.3% (4/310) had been previously immunized with PCV13 and 0.6% (2/310) with PPV 23 polysaccharide vaccine, and 1.3% (4/310) with in uenza vaccine. (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) in CAP, 13 (7)(8)(9)(10)(11)(12)(13)(14)(15) in meningitis, and 12 (9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) in patients with other diagnoses (Table 2). ).…”

“…However, these ndings were obtained from small studies of children admitted to few hospitals. Another study identi ed the molecular characteristics of serotypes 11A, 23A, 15B/C, aiming at documenting the importance of capsular switching in the spread of non-vaccine serotypes causing IPD in children [20]. However, there is a lack of epidemiological data regarding IPD burden, serotype distribution, and clinical characteristics of adults hospitalized due to IPD in Colombia.…”