Streptococcus pneumoniae prevalence in nasopharynx, oropharynx and gingival sulcus in Brazilian adults:A preliminary study.

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.

Pneumococcal nasopharyngeal carriage among children in Brazil prior to the introduction of the 10-valent conjugate vaccine: a culture- and PCR-based survey.

We performed two different approaches (broth enrichment step prior to culture (BEC) and PCR (BEPCR)) for detecting Streptococcus pneumoniae from nasopharyngeal specimens collected from 242 children aged <6 years attending one hospital (n = 140) and one childcare centre (n = 102) in a major urban area in Brazil. These specimens were collected immediately before the introduction of the 10-valent pneumococcal conjugate vaccine (PCV10) and the 13-valent vaccine (PCV13) for routine use in Brazil. Results were compared with previous findings obtained with direct culture (DC) on a selective medium. Colonisation prevalence was 58·3% (n = 141), being higher among children attending the childcare centre (62·7% vs. 55%). The culture-based methods (DC and BEC) enabled the detection of S. pneumoniae in 119 (49·2%) and 115 (47·5%) children, respectively. The PCR-based method (BEPCR) was more sensitive and 137 (56·6%) carriers were identified. Twenty-six serogroups/serotypes were identified, predominantly 6B, 19F, 14, 6A, 15C and 23F. Multiple colonisation was observed in 13 (5·4%) children. The estimated serotypes coverage of available PCVs was 40·4% for the 10-valent (included in the Brazilian immunisation programme) and 55·8% for the 13-valent (only available in private clinics). The use of robust approaches to obtain a more realistic insight about the asymptomatic carrier status is of paramount importance to estimate and assess the impact of vaccine implementation. The combination between culture-based and molecular methods constitutes a suitable strategy.

Wolbachia spp. interfere na detecção molecular de Ehrlichia canis e Anaplasma platys em cães com microfilaremia / Wolbachia spp. interferes with molecular detection of Ehrlichia canis and Anaplasma platys in microfilaremic dogs

This report aimed to study the interference in molecular testing for Ehrlichia canis and Anaplasma platys in blood of 155 dogs from the coastal region of Rio de Janeiro. Five Anaplasmataceae positive samples but negative for E. canis and A. platys, from microfilaremic animals, were chosen for sequencing. These sequences, when compared to Gen et Bank database, showed 88% to 100% similarity with Wolbachia spp. denoting an interference in the detection of DNA from other members of Anaplasmataceae, possibly due to a high concentration of Wolbachia spp. DNA.(AU)