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PubMed2002

Streptococcus gallinaceus sp. nov., from chickens.

Three isolates of an unknown Gram-positive, catalase-negative, chain-forming, coccus-shaped organism isolated from an outbreak of septicaemia in a flock of adult broiler parents were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the bacterium represents a new subline within the genus Streptococcus, related to, albeit distinct from, Streptococcus acidominimus, Streptococcus ovis, Streptococcus suis and close relatives. The unknown bacterium was readily distinguished from all recognized streptococcal species by biochemical tests. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium from chickens be classified as Streptococcus gallinaceus sp. nov. The type strain is CCUG 42692T (= CIP 107087T).

Animals↗
PubMed1989

A qualitative and quantitative study of the cellular fatty acids of 'Streptococcus milleri' with capillary gas chromatography.

Fatty acid analysis was done with GC and GC-MS on 21 strains of 'Streptococcus milleri', representative of the various proposed species. Although no qualitative differences were found in the fatty acid profiles, discriminant analysis of the quantitative data revealed three groups. Streptococcus anginosus and Streptococcus constellatus were indistinguishable but separated from the other two groups which comprised Streptococcus intermedius, with a wide fermentation pattern and Streptococcus intermedius with a narrow fermentation pattern. Three of the strains could be distinguished from the others by a 'fingerprint' of a particularly prominent fatty acid peak. The results support the suggestion that there is more than one species in this group of organisms and that the technique might be of value in epidemiological investigations of 'S. milleri'.

Fatty Acids↗
PubMed1998

Unconventional organization of the division and cell wall gene cluster of Streptococcus pneumoniae.

The genes responsible for cell wall biosynthesis and cell division (dcw genes) were identified and sequenced in Streptococcus pneumoniae. The genetic organization of the dcw cluster in Streptococcus pneumoniae differed significantly from the clusters of other bacteria reported to date. In particular, the genes corresponding to the 2 min region of the Escherichia coli chromosome were found distributed in three genetically separate regions of the Streptococcus pneumoniae chromosome. The first region contained the expected ftsA and ftsZ cell division genes at one end and pbp2b, ddl and murF at the other end. The murD, murG and divIB genes, always found located upstream of ftsA, were found in a second region separated from the first. A third region contained the yllC, yllD, pbp2x and mraY genes. The chromosomal region downstream of ftsZ was also sequenced and characterized. In Streptococcus pneumoniae this region contains four ORFs, all of unknown function, and an ORF encoding the Bacillus subtilis DivIVA homologue. The gene order and the organization of this region was found to be conserved in Staphylococcus aureus, Streptococcus pyogenes and Bacillus subtilis, raising the possibility that previously unidentified loci may also be involved in division.

Bacterial Proteins↗
PubMed1996

Inducer expulsion and the occurrence of an HPr(Ser-P)-activated sugar-phosphate phosphatase in Enterococcus faecalis and Streptococcus pyogenes.

Inducer expulsion, a phenomenon in which rapidly metabolizable sugars cause cytoplasmic dephosphorylation and efflux of pre-accumulated sugar-phosphates (sugar-P), has been documented for Streptococcus pyogenes, Streptococcus bovis, and Lactococcus lactis, but not for other Gram-positive bacteria. Using intact cells and membrane vesicles, we show that Enterococcus faecalis exhibits both inducer exclusion and inducer expulsion, and that the latter phenomenon is dependent on the metabolite-activated ATP-dependent HPr(Ser) kinase that phosphorylates Ser-46 in HPr of the phosphotransferase system. A small, heat-stable, membrane-associated, HPr(Ser-P)-activated sugar-P phosphatase (Pase II), previously identified only in Lc. lactis, is shown to be present in extracts of Enterococcus faecalis and Streptococcus pyogenes but not in those of Staphylococcus aureus, Streptococcus mutans, Streptococcus salivarius, or Bacillis subtilis, organisms that do not exhibit the inducer expulsion phenomenon. Further, Lactobacillus brevis, an organism that exhibits inducer expulsion by a different mechanism, also apparently lacks Pase II. The results reveal that Pase II is present in those organisms that exhibit the coupled sugar-P hydrolysis/expulsion mechanism but not those that lack this mechanism. They provide correlative evidence that Pase II initiates inducer expulsion in species of enterococci, streptococci and lactococci.

Biological Transport↗
PubMed2005

A unique nine-gene comY operon in Streptococcus mutans.

Many Gram-positive and Gram-negative bacteria possess natural competence mechanisms for DNA capture and internalization. In Bacillus subtilis, natural competence is absolutely dependent upon the presence of a seven-gene operon known as the comG operon (comGA-G). In species of Streptococcus, this function has been described for a four-gene operon (comYA-D in Streptococcus gordonii and cglA-D in Streptococcus pneumoniae). In this study, a nine-orf operon (named comYA-I) required for natural competence in Streptococcus mutans was identified and characterized. Orf analysis of this operon indicates that the first four Orfs (ComYA-D) share strong homology with ComYA-D of S. gordonii and CglA-D of S. pneumoniae, the fifth to seventh Orfs (ComYE-G) match conserved hypothetical proteins from various species of Streptococcus with ComYF possessing a predicted ComGF domain, the eighth Orf (ComYH) shows a strong homology to numerous DNA methyltransferases from restriction/modification systems, and the ninth Orf (ComYI) is homologous to acetate kinase (AckA). RT-PCR analysis of the orf junctions confirmed that all nine orfs were present in a single transcript, while real-time RT-PCR analysis demonstrated that these orfs were expressed at a level very similar to that of the first orf in the operon. Mutations were constructed in all nine putative orfs. The first seven genes (comYA-G) were found to be essential for natural competence, while comYH and comYI had reduced and normal natural competence ability, respectively. Analyses of S. mutans comY-luciferase reporter fusions indicated that comY expression is growth-phase dependent, with maximal expression at an OD(600) of about 0.2, while mutations in ciaH, comC and luxS reduced the level of comY expression. In addition, comY operon expression appears to be correlated with natural competence ability.

Bacterial Proteins↗
PubMed2006

Horizontal transfer of the immunoglobulin A1 protease gene (iga) from Streptococcus to Gemella haemolysans.

Bacterial IgA1 proteases share the ability to cleave human IgA1 at the hinge region. Nature has developed this trait along at least five independent evolutionary lineages. To obtain further insight into the phylogeny and function of IgA1 proteases, the nucleotide sequence of the iga gene that encodes the IgA1 protease was determined from two Streptococcus mitis strains and one Gemella haemolysans strain. Heterologous expression in Escherichia coli confirmed that the genes encode human IgA1-cleaving activity. IgA1 proteases from Streptococcus and G. haemolysans shared structural features, including a motif typical for zinc-dependent metalloproteases of clan MA(E) family M26 and an N-terminal signal sequence followed by an LPXTG cell-wall-anchor motif and two putative membrane-spanning domains. In addition, they all harboured a repeat region preceding the active site of the protease. In the streptococcal IgA1 proteases, a G5 domain, which has been suggested to bind N-acetylglucosamine, was identified. Conservation of these structures in otherwise diverse proteases suggests that they are essential to the biological function of the enzyme. The phylogenetic distribution of homologous iga genes and conservation of gene order in the iga gene region in different Streptococcus species, combined with the sequence homologies, strongly suggest that the iga gene is more ancient in Streptococcus than in G. haemolysans, and therefore that the IgA1 protease gene was transferred from Streptococcus to G. haemolysans.

Base Sequence↗
PubMed2005

Acute guttate psoriasis patients have positive streptococcus hemolyticus throat cultures and elevated antistreptococcal M6 protein titers.

To further study the role of Streptococci hemolyticus infection and streptococcal M6 protein in the pathogenesis of acute guttate psoriasis, streptococcal cultures were taken from the throats of 68 patients with acute guttate psoriasis. PCR technique was applied to detect M6 protein encoding DNA from those cultured streptococci. Pure M6 protein was obtained by Sephacry/S-200HR and Mono-Q chromatography from proliferated Streptococcus hemolyticus. Antistreptococcal M6 protein titers were measured in the serum of patients with acute guttate psoriasis, plaque psoriasis and healthy controls by ELISA. A high incidence of Streptococcus hemolyticus culture was observed in the guttate psoriatic group compared with the plaque psoriasis and control groups. Fourteen strains of Streptococcus hemolyticus were cultured from the throats of 68 acute guttate psoriasis patients. Of these, 5 strains contain DNA encoding the M6 protein gene as confirmed by PCR technique. More than 85% purification of M6 protein was obtained from Streptococcus pyogenes. Applying our pure M6 protein with the ELISA methods, we found that the titer of antistreptococcal M6 protein was significantly higher in the serum of guttate psoriasis patients than in the control or plaque psoriasis groups (P < 0.01). We verified that patients of acute guttate psoriasis have a high incidence of Streptococcus hemolyticus in their throats and raised titers of antistreptococcal M6 protein in their sera.

Adolescent↗
PubMed1989

Molecular characterization of a surface protein antigen gene from serotype c Streptococcus mutans, implicated in dental caries.

The complete nucleotide sequence of the gene for a cell-surface protein antigen (PAc) of Streptococcus mutans MT8148 (serotype c) was determined. The pac gene consisted of 4695 bp and coded for a 170773D protein. The pac gene product contained a putative 38 amino acid signal peptide, resulting in a 166817D mature protein. A potential promoter sequence and a putative Shine-Dalgarno sequence preceded the open reading frame. Two internal repeating amino acid sequences were present in the PAc. One repeating region located in the N-terminal region was rich in alanine, and the other located in the central region was rich in proline. Southern blot analysis under the less stringent condition (allowing up to 35% base mismatch) revealed that the probe covering the proline-rich region hybridized to DNA preparations from strains of Streptococcus cricetus, Streptococcus sobrinus and Streptococcus downei as well as Streptococcus mutans.

Amino Acid Sequence↗
PubMed1992

Reduced nicotinamide adenine dinucleotide oxidase involvement in defense against oxygen toxicity of Streptococcus mutans.

The growth inhibition of the Streptococcus mutans group, including Streptococcus mutans, Streptococcus cricetus, Streptococcus rattus and Streptococcus sobrinus, on glucose by oxygen and the properties of reduced nicotinamide adenine dinucleotide (NADH) oxidase induced by oxygen, using a representative oxygen-tolerant strain, were examined. The growth response to oxygen varied among strains and correlated with the level of NADH oxidase activity in the cell extract. The induced synthesis of NADH oxidase as well as superoxide dismutase was affected by oxygen tension and energy sources. The induced NADH oxidase involved at least two types, major H2O-forming NADH oxidase and minor H2O2-forming NADH oxidase activity. In the presence of a scavenger of H2O2, pyruvate, the growth inhibition by oxygen in an oxygen-sensitive strain (GS5) was protected but not in another oxygen-sensitive strain (MT8148). The high level of induced H2O-forming NADH oxidase activity protected against oxygen toxicity.

Aerobiosis↗
PubMed2004

Characterization of Streptococcus bovis from the rumen of the dromedary camel and Rusa deer.

AIMS: Isolation and characterization of Streptococcus bovis from the dromedary camel and Rusa deer. METHODS AND RESULTS: Bacteria were isolated from the rumen contents of four camels and two deer fed lucerne hay by culturing on the semi-selective medium MRS agar. Based on Gram morphology and RFLP analysis seven isolates, MPR1, MPR2, MPR3, MPR4, MPR5, RD09 and RD11 were selected and putatively identified as Streptococcus. The identity of these isolates was later confirmed by comparative DNA sequence analysis of the 16S rRNA gene with the homologous sequence from S. bovis strains, JB1, C14b1, NCFB2476, SbR1, SbR7 and Sb5, from cattle and sheep, and the Streptococcus equinus strain NCD01037T. The percentage similarity amongst all strains was >99%, confirming the identification of the camel isolates as S. bovis. The strains were further characterized by their ability to utilize a range of carbohydrates, the production of volatile fatty acids (VFA) and lactate and the determination of the doubling time in basal medium 10 supplemented with glucose. All the isolates produced l-lactate as a major fermentation end product, while four of five camel isolates produced VFA. The range of carbohydrates utilized by all the strains tested, including those from cattle and sheep were identical, except that all camel isolates and the deer isolate RD11 were additionally able to utilize arabinose. CONCLUSIONS: Streptococcus bovis was successfully isolated from the rumen of camels and deer, and shown by molecular and biochemical characterization to be almost identical to S. bovis isolates from cattle and sheep. SIGNIFICANCE AND IMPACT OF THE STUDY: Streptococcus bovis is considered a key lactic acid producing bacterium from the gastrointestinal tract of ruminants, and has been implicated as a causative agent of lactic acidosis. This study is the first report of the isolation and characterization of S. bovis from the dromedary camel and Rusa deer, and suggests a major contributive role of this bacterium to fermentative acidosis.

Animals↗
PubMed2002

[The utility of the Pneumonia PORT prediction rule for evaluating the severity of community-acquired pneumonia in Japan. The relationship between disease severity and drug-resistant Streptococcus pneumoniae].

To examine the utility of the Pneumonia PORT prediction rule for evaluating the severity of community-acquired pneumonia (CAP) in Japan, 127 consecutive patients with CAP admitted during one-year period were recruited and stratified by the rule. The relationship between CAP severity determined by the rule and drug-resistant Streptococcus pneumoniae was also investigated. The number of the patients classified into each class was 20 (15.7%) in class I, 32 (25.2%) in class II, 32 (25.2%) in class III, 31 (24.4%) in class IV, and 12 (9.4%) in class V, respectively. Risk class-specific mortality rate was 0% in class I and II, 3.1% in class III, 3.2% in class IV, and 41.7% in class V, respectively. Twenty-seven patients (21.3%) were diagnosed as pneumococcal pneumonia. In terms of penicillin-susceptibility of Streptococcus pneumoniae, 19 strains (70.4%) were penicillin-susceptible Streptococcus pneumoniae (PSSP). Five (18.5%) were penicillin-intermediate Streptococcus pneumoniae (PISP), and 3 (11.1%) were penicillin-resistant Streptococcus pneumoniae (PRSP). Highly resistant pneumococci with penicillin MIC > or = 4.0 micrograms/mL was not observed. For severity of drug-resistant pneumococcal pneumonia, 3 patients infected with PISP were classified as class IV, 2 with PISP were as class V, 2 with PRSP were as class IV, and 1 with PRSP was as class V. The patients with drug-resistant pneumococcal pneumonia were classified as high risk classes (class IV to V), however, the mortality rate was low (0%). In conclusion, the Pneumonia PORT prediction rule is effective for evaluating the severity of CAP in Japan, especially in classifying the class V patients who are related to high mortality. The mortality rate of the patients with drug-resistant pneumococcal pneumonia was low.

Aged↗
PubMed2001

In vitro activities of the novel ketolide telithromycin (HMR 3647) against erythromycin-resistant Streptococcus species.

The in vitro susceptibilities of 184 erythromycin-resistant streptococci to a novel ketolide, telithromycin (HMR 3647), were tested. These clinical isolates included 111 Streptococcus pyogenes, 18 group C streptococcus, 18 group G streptococcus, and 37 Streptococcus pneumoniae strains. The MICs for all but eight S. pyogenes strains were < or =0.5 microg/ml, indicating that telithromycin is active in vitro against erythromycin-resistant Streptococcus strains. All strains for which MICs were > or =1 microg/ml had an erm(B) resistance gene and six strains for which MICs were > or =4 microg/ml had a constitutive erm(B) gene (MIC range, 4 to 64 microg/ml). Interestingly, for S. pneumoniae strains with a constitutive erm(B) gene, MICs were < or =0.25 microg/ml (MIC range, < or =0.008 to 0.25 microg/ml). Our in vitro data show that for S. pyogenes strains which constitutively express the erm(B) methylase gene, MICs are so high that the strains might be clinically resistant to telithromycin.

Anti-Bacterial Agents↗
PubMed1984

Lactose transport in Streptococcus mutans: isolation and characterization of factor IIIlac, a specific protein component of the phosphoenolpyruvate-lactose phosphotransferase system.

The transport of lactose in Streptococcus mutans is mediated via an inducible phosphoenolpyruvate-lactose phosphotransferase system. This system requires for catalytic activity a membrane fraction (enzyme II), two general proteins called enzyme I and HPr, and a soluble specific protein termed factor IIIlac. This protein factor was purified from S. mutans ATCC 27352 by chromatographies on DEAE-cellulose, hydroxylapatite, Ultrogel AcA 34, and phosphocellulose. The purified protein migrated as a single band with a molecular weight of 10,000 on polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and urea. The molecular weight calculated from the amino acid composition was 10,541. Gel filtration of the native protein gave a molecular weight of 41,500. Its isoelectric point was ca. 4.70. A specific antiserum was prepared against purified factor IIIlac. Immunodiffusion experiments revealed that only cellular extracts from lactose-grown cells contained factor IIIlac. A cross-reaction was observed with all of the S. mutans strains tested as well as with Streptococcus sanguis 10556, Streptococcus lactis 11454, and Staphylococcus aureus 6538. No precipitin band was observed with extracts of Streptococcus salivarius, Streptococcus faecalis, Lactobacillus casei, and Bacillus subtilis.

Amino Acids↗
PubMed1984

Penicillin-induced lysis of Streptococcus mutans.

Treatment of Streptococcus mutans GS-5 cells with concentrations of penicillin G within a relatively narrow range resulted in substantial lysis. This penicillin-induced lysis was dependent upon cell density and pH of the lysis medium. Other oral streptococci (Streptococcus sobrinus, Streptococcus rattus, and Streptococcus cricetus) also demonstrated substantial levels of penicillin-induced lysis under appropriate conditions. Lesser degrees of lysis were seen in a related organism, Streptococcus ferus.

Dose-Response Relationship, Drug↗
PubMed1986

Isolation and characterization of a 60-kilodalton salivary glycoprotein with agglutinating activity against strains of Streptococcus mutans.

A bacterial agglutinin specific for strains of Streptococcus mutans was isolated from human saliva. Physiochemical analyses showed the agglutinin to be a glycoprotein with a molecular weight of 60,000. The agglutinin aggregated four of the eight strains of Streptococcus mutans tested but did not aggregate the strains of Streptococcus salivarius, Streptococcus sanguis, and Streptococcus mitis tested. Chemical modification of carbohydrate moieties of the agglutinin with sodium metaperiodate had no effect on aggregation, whereas modification of the polypeptide portion with trypsin abolished aggregating activity. A set of five murine hybridoma antibodies was employed to further analyze the agglutinin. Two carbohydrate-specific antibodies, directed against D-mannose and N-acetylgalactosamine moieties, respectively, failed to block agglutinin- or whole saliva-mediated aggregation of S. mutans cells. In contrast, two antibodies directed against pronase-sensitive antigenic sites blocked both agglutinin- and saliva-mediated aggregation of S. mutans cells. Western blot analysis with the agglutinin-specific hybridoma antibodies demonstrated the agglutinin in whole saliva and in artificial tooth pellicles formed on hydroxyapatite beads incubated with saliva. These results suggest that a 60-kilodalton glycoprotein of human saliva is a bacterial agglutinin with specificity for certain strains of S. mutans. They further suggest that aggregation is mediated by polypeptide rather than carbohydrate determinants of the glycoprotein.

Agglutination↗
PubMed1990

Characterization of Streptococcus gordonii (S. sanguis) PK488 adhesin-mediated coaggregation with Actinomyces naeslundii PK606.

Intergeneric coaggregation of Streptococcus gordonii (S. sanguis) PK488 and Actinomyces naeslundii PK606 was studied by using coaggregation-defective (Cog-) mutants of both strains. A streptococcal protein of 38 kilodaltons was identified with anti-S. gordonii serum absorbed with Cog- cells of the streptococcus. Absorbed immunoglobulin G specifically blocked coaggregation of the streptococcus-actinomyces pair but did not affect the coaggregation of the streptococcus with other coaggregation partners. The 38-kilodalton protein was found in the supernatant of mild sonicated cell suspensions and was extracted from whole cells with sodium barbital or with 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CHAPS). An immunoreactive protein of the same size was found in sonicated cell supernatants of several other oral streptococci that also coaggregated with A. naeslundii PK606. Inhibition of S. gordonii PK488-A. naeslundii PK606 coaggregation was not observed with any of 16 different sugars tested. We propose that a functionally similar adhesin that mediates coaggregations with A. naeslundii PK606 is expressed by several species of the genus Streptococcus.

Actinomyces↗
PubMed1995

Adherence of Candida albicans to a cell surface polysaccharide receptor on Streptococcus gordonii.

Candida albicans ATCC 10261 and CA2 bound to cells of the oral bacteria Streptococcus gordonii, Streptococcus oralis, and Streptococcus sanguis when these bacteria were immobilized onto microtiter plate wells, but they did not bind to cells of Streptococcus mutans or Streptococcus salivarius. Cell wall polysaccharide was extracted with alkali from S. gordonii NCTC 7869, the streptococcal species to which C. albicans bound with highest affinity, and was effective in blocking the coaggregation of C. albicans and S. gordonii cells in the fluid phase. When fixed to microtiter plate wells, the S. gordonii polysaccharide was bound by all strains of C. albicans tested. The polysaccharide contained Rha, Glc, GalNAc, GlcNAc, and Gal and was related compositionally to previously characterized cell wall polysaccharides from strains of S. oralis and S. sanguis. The adherence of yeast cells to the immobilized polysaccharide was not inhibitable by a number of saccharides. Antiserum raised to the S. gordonii NCTC 7869 polysaccharide blocked adherence of C. albicans ATCC 10261 to the polysaccharide. The results identify a complex cell wall polysaccharide of S. gordonii as the coaggregation receptor for C. albicans. Adherent interactions of yeast cells with streptococci and other bacteria may be important for colonization of both hard and soft oral surfaces by C. albicans.

Candida albicans↗
PubMed1995

Use of a novel mobilizable vector to inactivate the scrA gene of Streptococcus sobrinus by allelic replacement.

The virulence factors of the cariogenic bacterium Streptococcus sobrinus have been difficult to assess because of a lack of tools for the genetic manipulation of this organism. The construction of an Escherichia coli-Streptococcus shuttle vector, pDL289, that can be mobilized into S. sobrinus by the conjugative plasmid pAM beta 1 was described in a previous report. The vector contains pVA380-1 for replication and mobilization in streptococci, the pSC101 replicon for maintenance in E. coli, a kanamycin resistance marker that functions in both hosts, and the multiple cloning site and lacZ from pGEM7Zf(-). pDL289 is stable with or without selection in several species of Streptococcus. In this study, a derivative with a deletion in the minus origin of the pVA380-1 component of pDL289 was constructed. This derivative, pDL289 delta 202, was less stable than pDL289 in Streptococcus gordonii Challis, Streptococcus mutans, and S. sobrinus. Both pDL289 and pDL289 delta 202 were mobilizable by pAM beta 1 into S. sobrinus, with frequencies of 3 x 10(-6) and 1 x 10(-7) transconjugants per recipient CFU, respectively. The cloned scrA gene of S. sobrinus 6715-10 coding for the EIISuc of the sucrose-specific phosphoenolpyruvate phosphotransferase system was interrupted by the insertion of a streptococcal spectinomycin resistance gene active in E. coli and streptococci. The interrupted scrA gene was subcloned into both pDL289 and pDL289 delta 202. Each recombinant plasmid was introduced into the DL1 strain of S. gordonii Challis, which was then used as a recipient for the conjugative transfer of pAM beta 1. The latter plasmid was used to mobilize each recombinant plasmid from S. gordonii Challis DL1 to S. sobrinus 6715-10RF. Subsequently, recombinants derived from a double-crossover event were isolated on the basis of resistance to spectinomycin and susceptibility to kanamycin. Recombinational events were confirmed by Southern hybridization, and the inactivation of the EII Suc in double crossovers was confirmed by phosphotransferase system assays. This is the first report of allelic replacement in S. sobrinus.

Cloning, Molecular↗