Pseudopneumoniae, S. mitis, S. parasanguinis, S. australis, S. mutans, S. peroris, S. oligofermentans, S. intestinalis, S. vestibularis, S. cristatus, S. salivarius, S. gordonii, S. sanguinis, S. sinensis and Dolosigranulum pigrum. Reference, genome-sequenced, S. pneumoniae strain D39 [37] (GenBank accession # NC_008533) and TIGR4 [38] (GenBank accession # NZ_AAGY00000000) were utilized as controls throughout the study.psaACCTGCTGAAAAGAAACTCATTGTA AGGTCTTGATTTGTTCAGGAGTTCpsrPGCTGCTAGAACTCCAAGTAACACA TCACAAGTTGGAAATACTTCTGGAcodYTATAACGCATAAAATAGCCAAGCA ATTACATCAATTTTGAAACGCTCAcbpDTCCTGTTGATTTAGAACCATTTGA GAGGGAGTGACTTCTTCACAAAATEnoGACGGTACTCCTAACAAAGGTAAA ATAGCTGTAAAGTGGGATTTCAAGrrn, intergenic spacer regionTGYACACACCGCCCGT GGGTTBCCCCATTCRGNasopharyngeal samplesThe NP samples utilized in this work were part of a study of S. pneumoniae colonization conducted in Peru [14]. Children enrolled in the mentioned study were aged 0? years of age; more details on the study population can be found in our recent publication [14]. Briefly, samples were collected using rayon swabs and Asiaticoside A supplier immediately placed in 1 ml of transport medium [skim-milk, tryptone, glucose, and glycerol (STGG) [39] at 4uC and*From ref (44). doi:10.1371/journal.pone.0067147.tcomponents of new vaccine formulations are Ply [22,23], pneumococcal surface protein A (PspA) [24,25], pneumococcal surface protein C (PspC) [26] and pneumococcal surface antigen AExpression of Sp Genes in the Human NasopharynxFigure 1. PCR amplification of the lytA gene and RT-PCR detection of its transcript. (A) DNA was 18204824 extracted from NP samples and utilized as template in PCR reactions amplifying the lytA gene. The loads of pneumococcus cells in each NP sample is indicated below each lane. The larger the bacterial loads, greater the amount of DNA that should be obtained from each sample. This PCR reaction thus detected DNA from NP samples containing at least ,2.86104 CFU/ml (samples 8, 9 and 12). (B) RNA was extracted from the indicated NP sample and was utilized as template in RTPCR reactions targeting the lytA gene. Reactions were added (+) or not (2) with retrotranscriptase (RT). In both panels, the size of the lytA product is shown at left in base pairs. doi:10.1371/journal.pone.0067147.gFigure 2. In silico analysis of the especificity of primers to amplify the eno gene. Sequences of primers designed to ampify the S. pneumoniae eno gene were entered into the BLAST website. Among others, total query coverage of 100 and 75 was observed for S. pneumoniae strain ST556 or S. pyogenes MGAS1882, respectively. Left bottom panel shows that both the left and right primers in silico hybridyzed on the S. pneumoniae eno gene. Right bottom panel shows hybridization of only the left primer on the S. pyogenes eno gene. Part of the righ primer in silico hybridized somewhere else in the genome. doi:10.1371/journal.pone.0067147.gExpression of Sp Genes in the Human Nasopharynxtransported to a central laboratory usually MedChemExpress ML 281 within 4 h and then stored at 280uC. The density of S. pneumoniae (CFU/ml) in these NP samples had been previously investigated utilizing a molecular approach [14].copies. A standard curve was constructed and final copies of each gene target, and therefore mRNA copies, were calculated using the Bio-Rad CFX manager software.RT-PCR reactions DNA extractionStrains were grown overnight on blood agar plates, this culture was utilized to prepare a cell suspension in 200 ml of sterile DNA grade water. The suspensi.Pseudopneumoniae, S. mitis, S. parasanguinis, S. australis, S. mutans, S. peroris, S. oligofermentans, S. intestinalis, S. vestibularis, S. cristatus, S. salivarius, S. gordonii, S. sanguinis, S. sinensis and Dolosigranulum pigrum. Reference, genome-sequenced, S. pneumoniae strain D39 [37] (GenBank accession # NC_008533) and TIGR4 [38] (GenBank accession # NZ_AAGY00000000) were utilized as controls throughout the study.psaACCTGCTGAAAAGAAACTCATTGTA AGGTCTTGATTTGTTCAGGAGTTCpsrPGCTGCTAGAACTCCAAGTAACACA TCACAAGTTGGAAATACTTCTGGAcodYTATAACGCATAAAATAGCCAAGCA ATTACATCAATTTTGAAACGCTCAcbpDTCCTGTTGATTTAGAACCATTTGA GAGGGAGTGACTTCTTCACAAAATEnoGACGGTACTCCTAACAAAGGTAAA ATAGCTGTAAAGTGGGATTTCAAGrrn, intergenic spacer regionTGYACACACCGCCCGT GGGTTBCCCCATTCRGNasopharyngeal samplesThe NP samples utilized in this work were part of a study of S. pneumoniae colonization conducted in Peru [14]. Children enrolled in the mentioned study were aged 0? years of age; more details on the study population can be found in our recent publication [14]. Briefly, samples were collected using rayon swabs and immediately placed in 1 ml of transport medium [skim-milk, tryptone, glucose, and glycerol (STGG) [39] at 4uC and*From ref (44). doi:10.1371/journal.pone.0067147.tcomponents of new vaccine formulations are Ply [22,23], pneumococcal surface protein A (PspA) [24,25], pneumococcal surface protein C (PspC) [26] and pneumococcal surface antigen AExpression of Sp Genes in the Human NasopharynxFigure 1. PCR amplification of the lytA gene and RT-PCR detection of its transcript. (A) DNA was 18204824 extracted from NP samples and utilized as template in PCR reactions amplifying the lytA gene. The loads of pneumococcus cells in each NP sample is indicated below each lane. The larger the bacterial loads, greater the amount of DNA that should be obtained from each sample. This PCR reaction thus detected DNA from NP samples containing at least ,2.86104 CFU/ml (samples 8, 9 and 12). (B) RNA was extracted from the indicated NP sample and was utilized as template in RTPCR reactions targeting the lytA gene. Reactions were added (+) or not (2) with retrotranscriptase (RT). In both panels, the size of the lytA product is shown at left in base pairs. doi:10.1371/journal.pone.0067147.gFigure 2. In silico analysis of the especificity of primers to amplify the eno gene. Sequences of primers designed to ampify the S. pneumoniae eno gene were entered into the BLAST website. Among others, total query coverage of 100 and 75 was observed for S. pneumoniae strain ST556 or S. pyogenes MGAS1882, respectively. Left bottom panel shows that both the left and right primers in silico hybridyzed on the S. pneumoniae eno gene. Right bottom panel shows hybridization of only the left primer on the S. pyogenes eno gene. Part of the righ primer in silico hybridized somewhere else in the genome. doi:10.1371/journal.pone.0067147.gExpression of Sp Genes in the Human Nasopharynxtransported to a central laboratory usually within 4 h and then stored at 280uC. The density of S. pneumoniae (CFU/ml) in these NP samples had been previously investigated utilizing a molecular approach [14].copies. A standard curve was constructed and final copies of each gene target, and therefore mRNA copies, were calculated using the Bio-Rad CFX manager software.RT-PCR reactions DNA extractionStrains were grown overnight on blood agar plates, this culture was utilized to prepare a cell suspension in 200 ml of sterile DNA grade water. The suspensi.