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PubMed1995

Transfer of Streptococcus adjacens and Streptococcus defectivus to Abiotrophia gen. nov. as Abiotrophia adiacens comb. nov. and Abiotrophia defectiva comb. nov., respectively.

We performed this study to determine the 16S rRNA sequences of the type strains of Streptococcus adjacens and Streptococcus defectivus and to calculate the phylogenetic distances between these two nutritionally variant streptococci (NVS) and other members of the genus Streptococcus. S. adjacens and S. defectivus belonged to one cluster, but this cluster was not closely related to other streptococcal species. A comparative analysis of the sequences of these organisms and other low-G+C-content gram-positive bacteria revealed that the two NVS species formed a distinct cluster and were only remotely related to the Aerococcus and Carnobacterium clusters. The highest level of homology (93.7%) was found between S. adjacens and Carnobacterium divergens. Carnobacterium species have meso-diaminopimelic acid in their cell walls, but S. adjacens and S. defectivus have L-lysine as the diamino acid at position 3 in their peptidoglycan tetrapeptides. On the basis of our findings and the results of previous phenotypic studies, we propose that the NVS species should be placed in a new genus, the genus Abiotrophia, as Abiotrophia adiacens comb. nov. and Abiotrophia defectiva comb. nov.

Base Sequence↗
PubMed1997

Streptococcus hyovaginalis sp. nov. and Streptococcus thoraltensis sp. nov., from the genital tract of sows.

Two groups of strains isolated from sows were shown to belong to new sublines in the genus Streptococcus. Based on phenotypic and phylogenetic analyses, we propose that these bacteria should be classified as two new species, Streptococcus hyovaginalis sp. nov. and Streptococcus thoraltensis sp. nov. These two species are found in the genital tract, but the capnophilic species S. thoraltensis may also occur in the intestinal tract of pigs. The type strain of S. hyovaginalis is SHV515 (= LMG 14710), and S69 (= LMG 13593) is the type strain of S. thoraltensis.

Animals↗
PubMed2000

Streptococcus didelphis sp. nov., a streptococcus with marked catalase activity isolated from opossums (Didelphis virginiana) with suppurative dermatitis and liver fibrosis.

beta-Haemolytic, catalase-positive, Gram-positive cocci that formed chains in broth media but did not react with Lancefield group antisera were isolated from skin lesions, spleen, liver and lungs of nine opossums, including eight from a research colony and one from a wildlife rehabilitation organization. The isolates had vigorous catalase activity that was retained on initial passage on non-blood-containing media, but this activity was lost in subsequent passages. The use of standard phenotypic tests did not lead to satisfactory identification of these organisms beyond the genus level, even if the aberrant catalase reaction was not considered. The 16S rRNA gene sequence of the isolates was most similar (96%) to Streptococcus dysgalactiae, but distinct from that species as 16S rRNA gene similarity of different strains of S. dysgalactiae was > 99%. Characterization of biochemical reactions and cell-wall fatty acid profiles also revealed significant differences between the opossum isolates and all other known Streptococcus spp., thus it is proposed as a new species with the name Streptococcus didelphis, sp. nov. The type strain is ATCC 700828T.

Animals↗
PubMed2001

Streptococcus australis sp. nov., a novel oral streptococcus.

Strains of streptococci were isolated from the mouths of children attending the United Dental Hospital, Sydney, Australia. These strains were analysed biochemically using the Rapid ID32 Strep microsystem, were subjected to DNA-DNA hybridization with other members of the oral streptococci and had their 165 rRNA analysed. On the basis of DNA-DNA hybridization, their nearest relative was Streptococcus parasanguinis, whereas, on the basis of 16S rRNA analysis, it was Streptococcus infantis. The name Streptococcus australis sp. nov. is proposed for the new species. The type strain is AI-1T (= ATCC 700641T = NCTC 13166T).

Base Composition↗
PubMed1983

Streptococcus garvieae sp. nov. and Streptococcus plantarum sp. nov.

Biochemical and chemotaxonomical studies were performed on some streptococci from frozen peas and bovine mastitis in an attempt to clarify their taxonomy. The results of the present and earlier studies indicate the pea and mastitis isolates represent two new species of the genus Streptococcus. The isolates from frozen peas are named Streptococcus plantarum sp. nov. and those from mastitis, Streptococcus garvieae sp. nov. The type strains are NCDO 1869 and NCDO 2155, respectively.

Animals↗
PubMed1998

Subtyping of Streptococcus dysgalactiae and Streptococcus uberis isolated from bovine mammary secretions by DNA fingerprinting.

Streptococcus dysgalactiae and Streptococcus uberis isolated from mammary secretions of cows from Tennessee and New Zealand were subtyped using polymerase chain reaction-based DNA fingerprinting. Such DNA fingerprinting using primer 8.6d (5'-GTAACGCC3') resulted in categorizing 116 S. dysgalactiae isolates into 25 different subtypes, with 17 subtypes observed in isolates from Tennessee and eight in isolates from New Zealand. All S. dysgalactiae DNA fingerprint profiles, regardless of origin, contained 700- and 330-base pair fragments. The majority of S. dysgalactiae isolates (73%) from Tennessee belonged to two subtypes. The remaining 23 isolates belonged to 15 different DNA fingerprint subtypes. Streptococcus dysgalactiae isolates from New Zealand (n = 32) were grouped into eight different subtypes; 66% belonged to two subtypes. A characteristic feature of S. dysgalactiae isolates from New Zealand was the presence of a 270-base pair DNA fragment seen infrequently in S. dysgalactiae isolates from Tennessee. When primer OPE-4 (5'-GTGACATGCC-3') was used, DNA fingerprinting differentiated S. uberis from Tennessee (n = 28) and New Zealand (n = 30) into 20 subtypes; 14 subtypes were observed in isolates from Tennessee, and six in isolates from New Zealand. All S. uberis DNA fingerprint profiles, regardless of origin, contained 1100-, 640-, and 450-base pair fragments. A characteristic feature of S. uberis isolates from New Zealand was the presence of a 300-base pair DNA fragment seen infrequently in S. uberis isolates from Tennessee. The most common subtypes of S. dysgalactiae and S. uberis from Tennessee herds were isolated in milk from lactating cows during monthly herd surveys, in milk from cows with clinical mastitis, and in mammary secretions from cows during the periparturient period, and thus were not confined to one particular stage of lactation. These data suggest that S. dysgalactiae and S. uberis from New Zealand are distinct from those isolated from the USA, and that DNA fingerprinting can be used as an epidemiological tool to differentiate streptococci and identify important sources of these mastitis pathogens on dairy farms.

Animals↗
PubMed2004

Polymerase chain reaction mediated identification of Streptococcus uberis and Streptococcus parauberis using species-specific sequences of the genes encoding superoxide dismutase A and chaperonin 60*.

Streptococcus uberis, a well-known bacterial pathogen associated with bovine mastitis, appears to be biochemically and serologically almost indistinguishable from the closely related species Streptococcus parauberis. In the present study, species-specific oligonucleotide primers were designed using internal parts of the genes sodA, encoding superoxide dismutase A, and cpn60 encoding chaperonin 60 of S. uberis and S. parauberis, respectively. The two oligonucleotide primer pairs allowed a rapid and reliable PCR-mediated identification and differentiation of both species. These studies, performed with S. uberis and S. parauberis reference cultures and clinical isolates from routine diagnostics, revealed that the occurrence of S. parauberis as causative agent of bovine mastitis appears to be rare. In addition the sodA and cpn60 sequence data confirmed that both species could taxonomically be classified to the pyogenic group of genus Streptococcus.

Animals↗
PubMed1984

Rutin-induced beta-glucosidase activity in Streptococcus faecium VGH-1 and Streptococcus sp. strain FRP-17 isolated from human feces: formation of the mutagen, quercetin, from rutin.

A fecal isolate, Streptococcus sp. strain FRP-17, and strain VGH-1 of Streptococcus faecium were shown to contain beta-glucosidases which converted rutin (quercetin-3-O-beta-D-glucose-alpha-L-rhamnose) to quercetin and were active against o-nitrophenyl-beta-D-glucose. The activity against rutin could be measured by increased mutagenicity in the Ames assay or visualized on thin-layer chromatography plates. In both organisms, the beta-glucosidase activities were inducible by the addition of rutin to the growth media. Several closely related strains of Streptococcus spp. lacked any beta-glucosidase activity. In cell preparations of the active organisms, activities with rutin and o-nitrophenyl-beta-D-glucose were optimal at pH 6.8 and could be enhanced by increasing the ionic strength of the assay system. At low ionic strengths, both quercetin and a new product (intermediate between the polarities of rutin and quercetin) were formed by the incubation of rutin with cell preparations of either active organism. This product disappeared with increased ionic strength, suggesting that it may be a reaction intermediate, quercetin-3-O-beta-D-glucose. These results suggest that the beta-glucosidase active against rutin and that active against o-nitrophenyl-beta-D-glucose are the same.

Bacterial Proteins↗
PubMed1992

Expression of Streptococcus mutans gtf genes in Streptococcus milleri.

The Streptococcus mutans glucosyltransferase (GTF) genes gtfB and gtfC were ligated into Escherichia coli-streptococcus shuttle plasmids and introduced into Streptococcus milleri. gtfB transformant KSB8 formed an S. mutans-like rough colony on mitis salivarius agar and expressed an extracellular GTF-I, of 158 kDa, and two cell-bound GTF-Is, of 158 and 135 kDa. gtfC transformant KSC43 formed a semirough colony on mitis salivarius agar and expressed primarily an extracellular GTF-SI, of 146 kDa, and two cell-bound GTF-SIs, of 146 and 152 kDa. The extracellular GTFs from KSB8 and KSC43 were purified and characterized. The two types of GTF also reacted specifically with monoclonal antibodies directed against each enzyme. Both enzymes synthesized significant amounts of oligosaccharides, consisting primarily of alpha-1,6-glucosidic linkages, as well as water-insoluble glucans, containing alpha-1,3-glucosidic linkages. Insoluble-glucan-synthesizing activities of both enzymes were stimulated (three- to sixfold) by the addition of dextran T10 and were inhibited in the presence of 1.5 M ammonium sulfate. The Km(s) for sucrose and the optimal pHs were also similar for both enzymes. However, when the transformants were grown in Todd-Hewitt broth supplemented with sucrose, KSC43 cells, expressing GTF-SI activity, adhered to glass surfaces in vitro, while KSB8 cells, expressing GTF-I activity, did not. These results are discussed relative to the potential role of the gtfB and gftC genes in S. mutans cariogenicity.

Ammonium Sulfate↗
PubMed2000

Identification of lipoprotein homologues of pneumococcal PsaA in the equine pathogens Streptococcus equi and Streptococcus zooepidemicus.

Streptococcus equi and Streptococcus zooepidemicus are major etiological agents of upper and lower airway disease in horses. Despite the considerable animal suffering and economic burden associated with these diseases, the factors that contribute to the virulence of these equine pathogens have not been extensively investigated. Here we demonstrate the presence of a homologue of the Streptococcus pneumoniae PsaA protein in both of these equine pathogens. Inhibition of signal peptide processing by the antibiotic globomycin confirmed the lipoprotein nature of the mature proteins, and surface exposure was confirmed by their release from intact cells by mild trypsinolysis.

Adhesins, Bacterial↗
PubMed1993

The cell-bound fructosyltransferase of Streptococcus salivarius: the carboxyl terminus specifies attachment in a Streptococcus gordonii model system.

The ftf gene, coding for the cell-bound beta-D-fructosyltransferase (FTF) of Streptococcus salivarius ATCC 25975, has been analyzed, and its deduced amino acid sequence has been compared with that of the secreted FTF of Streptococcus mutans and the levansucrases (SacBs) of Bacillus species. A unique proline-rich region detected at the C terminus of the FTF of S. salivarius preceded a hydrophobic terminal domain. This proline-rich region was shown to possess strong homology to the product of the prgC gene from pCF10 in Enterococcus faecalis, which encodes a pheromone-responsive protein of unknown function, as well as homology to the human proline-rich salivary protein PRP-4. A series of 3'-OH deletions of the S. salivarius ftf gene expressed in Streptococcus gordonii Challis LGR2 showed that the C terminus was required for cell surface attachment in this heterologous organism, as only the complete gene product was cell bound. This cell-bound activity was released in the presence of sucrose, suggesting that the mode of attachment and release of the S. salivarius FTF in S. gordonii was similar to that in its native host.

Amino Acid Sequence↗
PubMed2003

Molecular epidemiology of Streptococcus agalactiae (group B Streptococcus).

Group B Streptococcus (GBS) is a common cause of sepsis and meningitis in newborns, and causes disease in pregnant women and non-pregnant adults. The incidence of disease among non-pregnant adults, particularly those with underlying conditions, is increasing. In addition, many individuals are asymptomatically colonized with GBS. When compared to group A Streptococcus and Streptococcus pneumoniae, however, little is known about the pathogenesis, natural history and transmission dynamics of GBS. Various molecular tools have been utilized to study this organism, including both phenotypic techniques, such as serotyping and multilocus enzyme electrophoresis, and genotypic techniques such as plasmid analysis and pulsed-field gel electrophoresis. This review outlines the contributions of these methods to our current understanding of GBS infections.

Animals↗
PubMed1992

[Incidence of alpha-streptococcus having inhibitory activity against beta-streptococcus in patients with tonsillitis].

Inhibitory activity against the proliferation of group A beta-streptococci by alpha-streptococci, part of the normal flora of the oral cavity and throat, plays a role in host defense against infection. We speculated that there might be some relationship between alteration of oral flora and the presence of recurring tonsillitis. Accordingly, 141 cases of tonsillitis have been investigated for the detection of inhibitory alpha-streptococci. In patients scheduled for tonsillectomy, the mean number of inhibitory alpha-streptococci was preoperatively decreased and postoperatively increased. In patients in whom beta-streptococcus had been detected (including patients scheduled for tonsillectomy), the mean number of inhibitory alpha-streptococci was markedly decreased, indicating a high incidence of beta-streptococci in patients with tonsillitis. As inhibitory strains of alpha-streptococcus are sensitive to almost all antibiotics, it is suggested that chemotherapy may disrupt the normal flora of the throat. In summary, investigation of the oral cavity and the throat for the detection of inhibitory alpha-streptococcus appear to be useful in the management of group A beta-streptococcal infection.

Adolescent↗
PubMed2002

[Analysis of virulence-related proteins of Streptococcus suis type 2 from swine Streptococcus isolated in China].

Virulence-related proteins, muraminidase-released protein (MRP) and extracellular factor (EF) of Streptococcus suis type 2, were extracted from Jiangsu Isolate HA9801 and were used as antigens for preparation of antibodies. Bacterium cell envelope proteins and extracellular proteins of swine Streptococcus strains including 17 Chinese isolates, 1 German strain and 1 human isolate of Streptococcus suis type 2, were analyzed by SDS-PAGE and immunoblotting using the above antibodies, 11 strains produced MRP and 10 strains possessed EF or EF. They exist four phenotypes: MRP+ EF+ (8/19), MRP+ EF (1/19), MRP+ EF- (1/19), MRP- EF- (10/19).

Animals↗
PubMed1983

Streptococcus R (Streptococcus suis type II) infection in pigs in Japan.

Since the first outbreak of an epizootic disease on a pig farm in Shimane Prefecture in 1979, similar diseases have occurred continually on other 8 pig farms in the same prefecture until 1982. Main clinical symptoms of the disease were recumbency, convulsion, anorexia and paddling. The diseased pigs ranged mostly from 35 to 67 days of age. Monthly fatality on one pig farm for 1 year was 0.2 to 3.6%. Morbidities in affected litters were mostly at a level of 20 to 30% on 7 pig farms. The diseases were diagnosed as streptococcal meningitis and septicemia with each one of endocarditis and pneumonitis by pathological and bacteriological studies on 20 affected pigs. Distribution of piglets from a breeding farm to pig farms was considered as one of the causes of prevalence in the prefecture. Representative 20 strains of the isolates from diseased animals on 9 pig farms were identified as Streptococcus R (Streptococcus suis type II) by biological and serological examinations. For the latter examination, anti-Streptococcus R, S and T sera were prepared. It was also indicated that the disease had occurred in 8 prefectures in addition to Shimane, because positive results had been obtained from 41 strains submitted from those prefectures for serological diagnosis. The minimal inhibitory concentration was examined in 18 drugs to 19 isolates. It was the lowest in ampicillin and thiopeptin of all the drugs.

Animals↗
PubMed2006

In vitro inhibitory effects of Polygonum cuspidatum on bacterial viability and virulence factors of Streptococcus mutans and Streptococcus sobrinus.

OBJECTIVES: Polygonum cuspidatum has been used in Korean folk medicine to improve oral hygiene. This study was performed to evaluate the effects of methanol extract from root of P. cuspidatum (MEP) on bacterial viability and the virulence factors of Streptococcus mutans and Streptococcus sobrinus. METHODS: To test the effects of MEP on bacterial viability, we determined the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) against 20 bacterial strains, including S. mutans and S. sobrinus, using a micro-dilution assay. In case of S. mutans and S. sobrinus, the assays for time-kill and bacterial growth rate at sub-MIC concentrations were also performed. To determine effects of the extract on the virulence factors of S. mutans and S. sobrinus, the assays for sucrose-dependent adherence, water-insoluble glucan formation, glycolytic acid production, and acid tolerance were performed at sub-MIC levels. Phytochemical analysis for constituents of MEP was carried out. RESULTS: MEP showed a broad antibacterial range (MIC 0.5-4 mg/ml). The MBC was two to four times higher than the MIC. The time-kill curves showed S. mutans and S. sobrinus were significantly killed after 1h of incubation. At sub-MIC levels, doubling times of S. mutans and S. sobrinus dose-dependently increased up to 211% and 123%, respectively. At sub-MIC levels, MEP also showed inhibitory effects on the virulence factors of S. mutans and S. sobrinus in a dose-dependent fashion. Phytochemical analysis revealed the presence of alkaloids, sterol/terpenes, tannins, flavonoids, and carbohydrates. CONCLUSION: These data indicate that MEP has inhibitory effects on bacterial viability at higher concentrations (> or =MIC) and the virulence factors of S. mutans and S. sobrinus at sub-MIC concentrations, suggesting that it might be useful for the control of dental plaque formation and subsequent dental caries formation.

Anti-Bacterial Agents↗
PubMed1985

Effects of oxygen on pyruvate formate-lyase in situ and sugar metabolism of Streptococcus mutans and Streptococcus sanguis.

The strictly anaerobic metabolism of sugar in strains of Streptococcus mutans and Streptococcus sanguis was studied because deep layers of dental plaque are strictly anaerobic. Galactose-grown cells of these streptococcal strains had higher pyruvate formate-lyase activity than did glucose-grown cells. Among these strains, two strains of S. mutans had a significantly higher pyruvate formate-lyase activity than did the others. This enzyme is extremely sensitive to oxygen, and even in situ the enzyme was inactivated by exposure of the cells to air. Lactate was less than 50% of the total end product of the strictly anaerobic incubation of the galactose-grown cells of S. mutans with excess glucose, and a significant amount of formate, acetate, and ethanol was produced through the catalysis of pyruvate formate-lyase. But the cells exclusively produced lactate when exposed to air for 2 min before the anaerobic incubation. The metabolism of sorbitol by S. mutans was seriously impaired by the exposure of the cells to oxygen, and the metabolic rate was reduced to less than 1/20 of that found under strictly anaerobic conditions because of the inactivation of pyruvate formate-lyase. S. sanguis produced a smaller amount of the volatile products from glucose than did S. mutans because of the low level of pyruvate formate-lyase. However, the pyruvate formate-lyase in situ in S. sanguis was less sensitive to oxygen than was that in S. mutans. Because of this low sensitivity, S. sanguis metabolized glucose more rapidly under aerobic conditions, whereas the rates of the aerobic and anaerobic metabolism of glucose by S. mutans were similar, which suggests that S. mutans rather than S. sanguis can sustain the rapid sugar metabolism in the deep layers of dental plaque.

Acetyltransferases↗
PubMedDate not supplied

Susceptibility of Streptococcus mutans and Streptococcus sobrinus to cell wall inhibitors and development of a novel selective medium for S. sobrinus.

Representative strains of Streptococcus mutans and Streptococcus sobrinus showed differences in susceptibility to members of the monobactam group of beta-lactam antibiotics: S. sobrinus was less sensitive than S. mutans. The minimum inhibitory concentrations of aztreonam (AZT) and carumonam, both of which belong to this group, were 2,000 microg/ml for S. sobrinus and 125 microg/ml for S. mutans. Further addition of fosfomycin, bacitracin and sodium chloride to Mitis Salivarius agar (MS) supplemented with AZT resulted in growth inhibition of S. mutans and oral streptococci other than S. sobrinus, and was therefore used as a selective medium for S. sobrinus (MS-SOB medium). The average growth recovery of laboratory and clinically isolated strains of S. sobrinus on MS-SOB medium was 74.1% compared to that on MS medium. Seventy-eight percent of clinical samples in which S. sobrinus was detected yielded pure growth of S. sobrinus on MS-SOB medium.

Anti-Bacterial Agents↗