Non-typeable Streptococcus pneumoniae carriage isolates genetically similar to invasive and carriage isolates expressing capsular type 14 in Brazilian infants

Andrade, Ana Lúcia; Franco, Caritas Marquez; Lamaro‐Cardoso, Juliana; André, María Claudia; Oliveira, Leandro Luís Galdino de; Kipnis, André; Rocha, Cristyane Gonçalves Benicio Bastos; Andrade, João Guimarães de; Alves, Sueli L.A.; Park, In H.; Nahm, Moon H.; Almeida, Samanta Cristine Grassi; Brandileone, Maria Cristina C.

doi:10.1016/j.jinf.2010.07.003

Cited by 22 publications

(14 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Only a minority of S. pneumoniae strains do not react with the anticapsular antisera; these strains, defined as non-typable Streptococcus pneumoniae (NTPn), are thought to be non-encapsulated. NTPn are typically isolated from carriage (Andrade et al, 2010;Sá-Leão et al, 2006), but are also found in conjunctivitis (Carvalho et al, 2003), acute otitis media (Xu et al, 2011) and, rarely, in invasive disease (Beall et al, 2006). Non-typability can be due to different genetic modifications, such as partial or complete loss of the cps gene cluster (Hathaway et al, 2004), and the presence of a novel gene (Baldry et al, 2009), single point mutations (Arrecubieta et al, 1994) or sequence duplications (Waite et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Point mutations in wchA are responsible for the non-typability of two invasive Streptococcus pneumoniae isolates

et al. 2012

View full text Add to dashboard Cite

Non-typable Streptococcus pneumoniae (NTPn) strains are typically isolated from nasopharyngeal carriage or from conjunctivitis. Since the isolation of NTPn from invasive disease is rare, we characterized the genetic basis of the non-typability of two isolates obtained in Italy from two cases of bacteraemic pneumonia. MLST revealed that both NTPn belonged to ST191, which, according to the MLST database, is associated with serotype 7F. Sequencing of the capsular locus (cps) confirmed the presence of a 7F cps in both strains and revealed the existence of distinct single point mutations in the wchA gene (a glycosyltransferase), both leading to the translation of proteins truncated at the C terminus. To verify that these mutations were responsible for the non-typability of the isolates, a functional 7F WchA was overexpressed in both NTPn. The two NTPn along with their WchA-overexpressing derivatives were analysed by transmission electron microscopy and by high-resolution magic angle spinning NMR spectroscopy. Both NTPn were devoid of a polysaccharide capsule, and WchA overexpression was sufficient to restore the assembly of a serotype 7F capsule on the surface of the two NTPn. In conclusion, we identified two new naturally occurring point mutations that lead to non-typability in the pneumococcus, and demonstrated that WchA is essential for the biosynthesis of the serotype 7F capsule. INTRODUCTIONThe Gram-positive pathogen Streptococcus pneumoniae is a major cause of community-acquired pneumonia, as well as upper respiratory tract infections such as acute otitis media and sinusitis, and invasive diseases such as meningitis, bacteraemia and endocarditis. However, S. pneumoniae is also a commensal of the upper respiratory tract, especially of young children, who represent the reservoir for pneumococcal transmission within the community.The ability of the pneumococcus to invade sterile sites is related to the expression of a polysaccharide capsule, which provides a barrier against host cell-mediated phagocytosis and allows bacterial persistence in the blood (Brown et al., 1983). In addition, capsular polysaccharides (CPSs) are immunogenic and antibodies against CPSs provide protection against pneumococcal disease; therefore, all of the current pneumococcal vaccines are based on a combination of different CPSs, either unconjugated or conjugated to a carrier protein (Gladstone et al., 2011).To date, 93 capsular types (serotypes) have been described on the basis of their different genetic, biochemical and antigenic properties (Bentley et al., 2006;Calix & Nahm, 2010;Park et al., 2007). Each pneumococcal serotype corresponds to a distinct CPS, synthesized on the bacterial surface by enzymes which are encoded within a single capsule locus (cps), with a few notable exceptions (Llull et al., 1999). The sequencing of different cps loci has revealed the presence of a core set of genes common to all capsular types, namely wzg, wzh, wzd and wze (also known as cpsA, B, C and D), and of additional genes that are CPS-specific (Bentley...

show abstract

Section: Introductionmentioning

confidence: 99%

“…The characterization of NTPn by MLST has revealed the presence of specific non-typable pneumococcal lineages which have lost the cps gene cluster (Hanage et al, 2006;Hathaway et al, 2004) as well as of NTPn that are genetically related to encapsulated strains (Andrade et al, 2010;Hathaway et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Point mutations in wchA are responsible for the non-typability of two invasive Streptococcus pneumoniae isolates

et al. 2012

View full text Add to dashboard Cite

show abstract

“…However, three were ST1106 which is associated with serotype 14. Although previous studies have found non-typeable isolates genetically related to serotype 14 [56, 57], further investigation of our isolates using a serotype 14-specific PCR suggest that these isolates may lack part of the capsule locus or have capsule sequences that are sufficiently divergent that they are not detected by the serotype 14-specific PCR.…”

Section: Discussionmentioning

confidence: 63%

Long-term impact of pneumococcal polysaccharide vaccination on nasopharyngeal carriage in children previously vaccinated with various pneumococcal conjugate vaccine regimes

Boelsen

Dunne

Lamb

et al. 2015

Vaccine

View full text Add to dashboard Cite

Previously, the Fiji Pneumococcal Project (FiPP) evaluated reduced dose immunization schedules that incorporated pneumococcal protein conjugate and/or polysaccharide vaccine (PCV7 and 23vPPV, respectively). Immune hyporesponsiveness was observed in children vaccinated with 23vPPV at 12 months of age compared with children who did not receive 23vPPV. Here we assess the long-term impact of 23vPPV vaccination on nasopharyngeal carriage rates and densities of Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus and Moraxella catarrhalis. Nasopharyngeal swabs (n=194) were obtained from healthy children who participated in FiPP (now aged 5–7 years). S. pneumoniae were isolated and identified by standard culture-based methods, and serotyped using latex agglutination and the Quellung reaction. Carriage rates and densities of S. pneumoniae, H. influenzae, S. aureus and M. catarrhalis were determined using real-time quantitative PCR. There were no differences in the rate or density of S. pneumoniae, H. influenzae or M. catarrhalis carriage by PCV7 dose or 23vPPV vaccination in the vaccinated participants overall. However, differences were observed between the two main ethnic groups: Fijian children of Indian descent (Indo-Fijian) were less likely to carry S. pneumoniae, H. influenzae and M. catarrhalis, and there was evidence of a higher carriage rate of S. aureus compared with indigenous Fijian (iTaukei) children. Polysaccharide vaccination appeared to have effects that varied between ethnic groups, with 23vPPV vaccination associated with a higher carriage rate of S. aureus in iTaukei children, while there was a lower carriage rate of S. pneumoniae associated with 23vPPV vaccination in Indo-Fijian children. Overall, polysaccharide vaccination had no long-term impact on pneumococcal carriage, but may have impacted on S. aureus carriage and have varying effects in ethnic groups, suggesting current WHO vaccine schedule recommendations against the use of 23vPPV in children under two years of age are appropriate.

show abstract

“…Com predominância entre as crianças, soma 50% dos isolados resistentes à penicilina (ANDRADE et al, 2010;CASTAÑEDA et al, 2009 A pneumolisina também tem se mostrado necessária para a propagação de pneumococos dos pulmões para a corrente sangüínea (KADIOGLU et al, 2008).…”

Section: Polissacarídeo Capsular Sorotipo 14unclassified

Desenvolvimento e avaliação da resposta imune humoral de uma vacina anti-pneumocócica conjugada: polissacarídeo capsular sorotipo 14 - proteína de superfície pneumocócica A.

Santamaria¹

View full text Add to dashboard Cite

Non-typeable Streptococcus pneumoniae carriage isolates genetically similar to invasive and carriage isolates expressing capsular type 14 in Brazilian infants

Cited by 22 publications

References 47 publications

Point mutations in wchA are responsible for the non-typability of two invasive Streptococcus pneumoniae isolates

Point mutations in wchA are responsible for the non-typability of two invasive Streptococcus pneumoniae isolates

Long-term impact of pneumococcal polysaccharide vaccination on nasopharyngeal carriage in children previously vaccinated with various pneumococcal conjugate vaccine regimes

Desenvolvimento e avaliação da resposta imune humoral de uma vacina anti-pneumocócica conjugada: polissacarídeo capsular sorotipo 14 - proteína de superfície pneumocócica A.

Contact Info

Product

Resources

About