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Updated: Nov 5, 2025

Investigating the Effects of Probiotics on Pneumococcal Colonization Using an In Vitro Adherence Assay
Published on: April 28, 2014
Streptococcus pneumoniae prevalence in nasopharynx, oropharynx and gingival sulcus in Brazilian adults:A preliminary
P G Lomardo1, N T Cardoso-Marques2, L A Motta1
1Post-graduation in Dentistry, School of Dentistry, Universidade Federal Fluminense, Brazil.
Aim:
This study aimed to evaluate the prevalence of S. pneumoniae colonization in three different sites in healthy adults: nasopharynx, oropharynx and gingival sulcus.
Methods:
Two-hundred and sixty five adults, aged 20-60 years, who attended dental clinics in one public university (n = 106) and one military institution (n = 159) were enrolled in this study. Pneumococcal detection was performed by direct culture (DC) and PCR for lytA gene after a broth enrichment step. Capsular types were determined by sequential multiplex PCR.
Results:
We identified 18 (6.8%) pneumococcal carriers among 265 adults by PCR, but only one (0.4%) pneumococcal strain was isolated by DC method. Oropharynx (17; 6.4%) was the main source of S. pneumoniae. Colonization of gingival sulcus and nasopharynx was found in 4 (1.5%) and 2 (0.8%) adults, respectively. Nine distinct capsular types were detected from 9 adults and co-colonization with 2 serotypes was confirmed in 4 (1.5%) subjects. Factors associated with carriage were being females, low level of schooling, non-military and regular medication. We observed a low (6.8%) pneumococcal carriage prevalence, but oropharyngeal samples yielded more sensitive results, especially by the PCR-based detection methodology.
Conclusion:
Gingival sulcus was found to be a possible reservoir for S. pneumoniae independently of the oropharynx or nasopharynx colonization.
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