Streptococcus pneumoniae serotype 3 genotypes in invasive isolates from Colombia

Area of Science:

• Microbiology
• Epidemiology
• Genetics

Background:

• Streptococcus pneumoniae serotype 3 is a significant pathogen causing pneumonia, bacteremia, and meningitis.
• Understanding the genetic diversity and evolution of S. pneumoniae serotypes is crucial for public health interventions.

Purpose of the Study:

• To determine the circulating genotypes of Streptococcus pneumoniae serotype 3 isolates from invasive diseases in Colombia between 1994 and 2015.
• To analyze the genetic relatedness and clonal evolution of S. pneumoniae serotype 3 in the Colombian population.

Main Methods:

• Genotyping of 117 S. pneumoniae serotype 3 isolates using pulsed-field gel electrophoresis (PFGE).
• Multilocus sequence typing (MLST) was performed on representative isolates.
• Analysis of isolate data collected through a national laboratory surveillance program.

Main Results:

• The frequency of S. pneumoniae serotype 3 increased significantly from 2.7% (1994-1998) to 9.1% (2011-2015).
• Over 91% of isolates exhibited high genetic similarity (>77%), predominantly related to the Netherlands3-31 (PMEN31) clone CC180.
• Antimicrobial resistance was identified in two subtypes of the CC180 clone.

Conclusions:

• The pneumococcal population of capsular type 3 in Colombia demonstrates continuous and homogeneous circulation.
• The clonal group ST-180 is the dominant genotype for S. pneumoniae serotype 3 in Colombia.
• The findings highlight the importance of ongoing surveillance for S. pneumoniae serotype 3 and its evolving resistance patterns.