Summary Two main patterns of gene expression Streptococcus pneumoniae were observed during infection in the host by quantitative real time RT‐PCR; one was characteristic bacteria blood and tissue, such as brain lung. Gene characterized increased pneumolysin, pspA hrcA , while pneumococci tissue showed neuraminidases, metalloproteinases, oxidative stress competence genes. In vitro situations with similar detected liquid culture a newly developed pneumococcal model biofilm respectively. The...

The nucleotide sequence of comC, the gene encoding 17-residue competence-stimulating peptide (CSP) Streptococcus pneumoniae (L. S. Havarstein, G. Coomaraswamy, and D. A. Morrison, Proc. Natl. Acad. Sci. USA 92:11140-11144, 1995) was determined with 42 encapsulated strains different serotypes. A new allele, comC2, found in 13 strains, including type 3 Avery strain, A66, while all others carried a (now termed comC1) identical to that originally described for strain Rx1. predicted mature...

The important human pathogen Streptococcus pneumoniae was found to absorb factor H, an inhibitor of complement, from plasma. We identified the gene encoding a novel surface protein, H-binding complement (Hic), in pspC locus type 3 pneumococci. Unlike PspC proteins other serotypes, Hic is anchored cell wall by means LPXTG motif, and overall sequence homology various low. However, NH(2)-terminal region showed significant several proteins. A fragment Hic, covering this homologous region,...

The correlation between carbohydrate availability, pneumococcal biofilm formation, nasopharyngeal colonization, and invasion of the host has been investigated. Of a series sugars, only sialic acid (i.e., N-acetylneuraminic acid) enhanced formation in vitro, at concentrations similar to those free human saliva. In murine model carriage, intranasal inoculation significantly increased counts nasopharynx instigated translocation pneumococci lungs. Competition both acid-dependent phenotypes was...

ABSTRACT Susceptibilities to macrolides were evaluated in 267 Streptococcus pneumoniae isolates, of which 182 from patients with invasive diseases and 85 healthy carriers. Of the 98 resistant 20 strains showed an M phenotype carried mef . Strains that both (A) (E) found: 17 3 (E). The characteristics carrying genes properties mef- containing elements studied. belonged serotype 14, susceptible all antibiotics tested except erythromycin, appeared be clonally related by pulsed-field gel...

The success of Streptococcus pneumoniae (the pneumococcus) as a pulmonary pathogen is related to its restriction innate immune responses by respiratory epithelial cells. mechanisms used overcome this are incompletely elucidated. Pulmonary chemokine expression involves complex cellular and molecular networks, involving the epithelium, but specific interactions cytokines that control them defined. We show serotype 2 or 4 pneumococci induce only modest levels CXCL8 from cell lines, even in...

The mef(A) gene from a clinical isolate of Streptococcus pneumoniae exhibiting the M-type resistance to macrolides was found be part 7,244-bp chromosomal element Tn1207.1, which contained 8 open reading frames. orf2 encodes resolvase/invertase, and orf5 is homolog macrolide-streptogramin B msr(SA).

ABSTRACT Pneumococci frequently colonize the upper respiratory tract, and these pneumococci are believed to act as a reservoir for infection of lower tract bacteremia. We investigated how pneumococcal toxin pneumolysin affects capacity infect mouse. Wild-type Streptococcus pneumoniae serotype 2 3 strains, pneumolysin-deficient mutant, mutant with gene reinserted were used study differences in colonization disease. In addition, we also examined chimeric (capsule type switched from 3) gain...

The ZmpC zinc metalloproteinase of Streptococcus pneumoniae, annotated in the type 4 genome as SP0071, was found to cleave human matrix 9 (MMP-9). previously described IgA protease activity confirmed be specifically linked IgA1-protease/SP1154 metalloproteinase. MMP-9 is a cleaving extracellular gelatin and collagen activated by proteolytic cleavage like most proteases. involved variety physiological pathological degrading processes, including tissue invasion metastases opening blood-brain...

ABSTRACT The type 2 capsule locus of Streptococcus pneumoniae was characterized in Avery’s strain D39, which is the parent standard transformation recipients currently used pneumococcal research and largely as a virulent studies on pathogenesis infections. sequenced by using 21.7-kb PCR fragment from D39 genome template. Sequence data analysis showed presence 18 open reading frames, 17 have same direction transcription all are potentially involved biosynthesis. It also shown that R36A R6,...

Abstract Background Different models for biofilm in Streptococcus pneumoniae have been described literature. To permit comparison of experimental data, we characterised the impact pneumococcal quorum-sensing competence system on formation three models. For this scope, used two microtiter and one continuous culture system. Results In both influences stability structure late attachment phase synthetic stimulating peptide (CSP) restored wild type phenotypes comC mutants unable to produce...

The mef(A) gene was originally identified as the resistance determinant responsible for type M to macrolides, a phenotype frequently found in clinical isolates of Streptococcus pneumoniae and pyogenes. MefA defined secondary transporter Major Facilitator Superfamily driven by proton-motive force. However, when characterizing mef(A)-carrying elements Tn1207.1 Φ1207.3, another macrolide gene, msr(D), adjacent mef(A). To define respective contribution msr(D) resistance, 3 isogenic deletion...

Streptococcus pyogenes (Group A Streptococcus; GAS) is a pathogen of global significance. In the pre-antibiotic era, GAS was major cause childhood morbidity and mortality, but its spread rapidly declined until mid-2010s. The continuing increase in infections, associated with expansion M1UK lineage, observed first United Kingdom (UK) and, later, globally. Here, we endeavor to assess various determinants underlying post-pandemic upsurge, focus on microbial genomic features. We performed an...

The macrolide efflux gene mef(A) of the Streptococcus pyogenes clinical strain 2812A was found to be carried by a 52-kb chromosomal genetic element that could transferred conjugation chromosome other streptococcal species. characteristics this are typical conjugative transposons and named Tn1207.3. size Tn1207.3 established pulsed-field gel electrophoresis (PFGE), DNA sequencing analysis showed 7,244 bp at left end were identical those pneumococcal Tn1207.1 element. Tn1207.3-like elements...

Opsonization enhances Streptococcus pneumoniae–induced human monocyte–derived macrophage (MDM) apoptosis. Both depletion of complement and immunoglobulin from opsonizing serum blockade the macrophages CR1, CR3, FcγRII, FcγRIII partially decreased MDM apoptosis after S. pneumoniae phagocytosis, these effects correlated with reduced numbers internalized bacteria. Chloramphenicol inhibition protein synthesis by opsonized down-regulated subsequent Phagocytosis an unencapsulated mutant resulted...

ABSTRACT The role of pneumococcal surface protein C (PspC; also called SpsA, CbpA, and Hic) in sepsis by Streptococcus pneumoniae was investigated a murine infection model. pspC gene deleted strains D39 (type 2) A66 3), the mutants were tested being injected intravenously into mice. animals infected with mutant showed significant increase survival, 50% lethal dose up to 250-fold higher than that for wild type. Our findings indicate PspC affords decisive contribution development.

The association between the macrolide efflux gene mef(E) and tet(M) was studied in two clinical strains of Streptococcus pneumoniae that belonged to serotypes 19F 6A, respectively, were resistant both tetracycline erythromycin. mef(E)-carrying element mega (macrolide genetic assembly; 5,511 bp) found be inserted into a Tn916-like present chromosomes pneumococcal strains. In strains, integrated at same site, an open reading frame identical orf6 Tn916. new composite element, Tn2009, about 23.5...

Genetic element Φ1207.3 (formerly Tn1207.3) is a prophage of Streptococcus pyogenes which carries the macrolide efflux resistance genes mef(A)/msr(D) and capable conjugal transfer among streptococci. Complete nucleotide sequence showed that 52,491 bp in length contained 58 open reading frames (ORFs). A manual homology-based annotation with functional prediction hypothetical gene product was possible only for 34 out ORFs. codes two different C-methylation systems, several phage structural...

Streptococcus pneumoniae possesses large zinc metalloproteinases on its surface. To analyse the importance in virulence of three these metalloproteinases, intranasal challenge MF1 outbred mice was carried out using a range infecting doses wild type and knock-out pneumococcal mutant strains, order to compare survival. Observation survival percentages over time detection LD50s knock mutants proteinase genes comparison 4 TIGR4 strain revealed two major aspects: i) Iga ZmpB, present all strains...

The structure of the macrolide efflux genetic assembly (mega) element, its genomic locations, and association with other resistance determinants elements were investigated in 16 Streptococcus pneumoniae isolates carrying mef(E), which 1 isolate also carried tet(M) 4 erm(B). All a mega element similar size that included operon mef(E)-msr(D) encoding transport system. Among tetracycline-susceptible isolates, six different integration sites identified, five recognized inside open reading frames...

Competence for genetic transformation in Streptococcus pneumoniae is regulated by a quorum-sensing mechanism involving the pheromone competence stimulating peptide (CSP) encoded comC and two-component signal transduction system, ComD-ComE (TCS12). In presence of CSP, transmembrane histidine kinase ComD receptor activates response regulator ComE. The comC, comD comE genes are part an operon denoted as comCDE. this work, comCDE locus 17 S. strains was characterized DNA sequencing. Two major...

Pneumococcal surface protein C (PspC) is a virulence factor of Streptococcus pneumoniae previously shown to play role in bacterial adherence, invasion, and evasion complement. We investigated the this our murine models pneumococcal pneumonia with different strains. The deletion pspC strains serotypes 2, 3, 19F did not significantly alter host survival times model. In contrast, reduced serotype 4 strain, TIGR4, both bacteremia models. Therefore, systemic pulmonary determinant for S....