Int J Infect Dis. 2016 Apr 7. pii: S1201-9712(16)31018-9. doi: 10.1016/j.ijid.2016.04.005. [Epub ahead of print]

Serotypes and genotypes of Streptococcus pneumoniae isolates from Trinidad and Tobago.

Nurse-Lucas M1, McGee L2, Hawkins PA3, Swanston WH1, Akpaka PE4.

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There are currently 94 pneumococcal capsular polysaccharide serotypes and their prevalence differs somewhat by geographic region and the period studied. Infections by Streptococcus pneumoniae have been clinically diagnosed in Trinidad and Tobago and other Caribbean countries, however there are limited data on serotype and sequence type distributions in this country. The objective of this study was to determine serotypes and multilocus sequence types of invasive and non-invasive pneumococcal isolates from Trinidad and Tobago.


Ninety-eight pneumococcal isolates from several regional hospitals in the country were analyzed using both standard microbiological methods and molecular analysis. This included invasive (n=83) and selected non-invasive (n=15) strains recovered before (n=25) and after (n=73) the introduction of pneumococcal conjugated vaccine.


More than half of the isolates (54.1%) were recovered from children below 15 years of age, with the largest proportion being from children under 2 years of age (24.5%). The most prevalent serotypes were 19F (18.4%), 6B (15.3%), 23F (14.3%), 3 (11.2%), 19A (6.1%), 6A (5.1%), 14 (5.1%) and 9V (4.1%). The most common serotype/MLST combinations were 6B/ST138 (n=10, 10.2%), 3/ST180 (n=5, 5.1%), 23F/ST629 (n=5, 5.1%), 19F/ST8398 (n=4, 4.1%), and 3 each of 6B/ST145, 14/9V/ST156, 9V/ST162, 19A/320 and 3/ST10440.


This report gives the first glimpse of prevailing pneumococcal sequence types in the country, revealing that most of these isolates represented serotypes in PCV10 (61.2% of isolates) and PCV13 (83.7%). A detailed population study is warranted to fully determine the circulating pneumococcal sequence types and the implementation of an effective and continued surveillance system in Trinidad-Tobago is paramount to monitor vaccine impact.

Copyright © 2016. Published by Elsevier Ltd.


Invasive pneumococcal disease; Multilocus sequence typing; Pneumococcal conjugated vaccine; Sequence types; Trinidad & Tobago

PMID: 27062986 [PubMed - as supplied by publisher]