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PubMed2006

Antimicrobial susceptibility of Streptococcus pyogenes and Streptococcus pneumoniae: surveillance from 1993 to 2004 in Central Italy.

The susceptibility of 1870 Streptococcus pyogenes and 1595 Streptococcus pneumoniae to macrolides and lincosamides has been monitored from 1993 to 2004 in Central Italy. Among S. pyogenes, 30.2% were erythromycin resistant; 18.5% were also resistant to josamycin and clindamycin (MLS phenotype). After an increasing erythromycin resistance rate in 1993-1997 (maximum 53.16%), a definite decrease was observed since 2001 with resistance rates always less than 30%. Thirty six percent of pneumococcal isolates were erythromycin-resistant, with minor temporal fluctuations; the MLS phenotype was the most prevalent overall (32.6%) and in individual years. S. pneumoniae strains were also tested for susceptibility to beta-lactams and other antimicrobial agents: 11.2% were penicillin non-susceptible, with a gradually increasing prevalence after 2001 (maximum rate 17.3% in 2004), 31.15% were resistant to tetracycline, 4.9% to chloramphenicol, 0.74% to rifampin. All pneumococcal isolates were susceptible to teicoplanin and 99.9% to ceftriaxone and ofloxacin.

Drug Resistance, Bacterial↗
PubMed1993

An occurrence of equine transport pneumonia caused by mixed infection with Pasteurella caballi, Streptococcus suis and Streptococcus zooepidemicus.

An acute death occurred in a racehorse with pneumonia after long-distance transportation in December, 1990. Pasteurella caballi, Streptococcus suis and Streptococcus zooepidemicus were isolated from the lung at high rate. Specific antigens of these bacteria were also demonstrated immunohistologically in the pneumonic lesion. These findings indicated that the disease is equine transport pneumonia caused by a mixed infection of the three bacterial species. This is the first report on the isolation of P. caballi and S. suis from a racehorse in Japan.

Animals↗
PubMed1997

Antibiotic resistance in Streptococcus pneumoniae, Haemophilus influenzae and Streptococcus pyogenes in respiratory tract infections in outpatients.

Sensitivity patterns of Streptococcus pneumoniae, Haemophilus influenzae and Streptococcus pyogenes were studied prospectively in an outpatient population seeking medical advice for respiratory tract infections (RTI) in the Southern parts of Stockholm. In total, 3,214 nasopharyngeal and 1,907 throat swabs were cultured during January-February 1996. 32% of the patients had received antibiotics during the previous year. Reduced penicillin sensitivity in S. pneumoniae was rare (1.3%) and only seen in patients treated with antibiotics during the previous 4 months. Beta-lactamase production in H. influenzae was found in 13.4% of patients who had been treated with antibiotics during the last 4 months and in 7.9% of the others. No resistance (< 1%) to erythromycin was seen in S. pyogenes. In this population-based surveillance, the levels of resistance in common respiratory tract pathogens were thus low and correlated to previous antibiotic treatment. Strict indications for antibiotic treatment in uncomplicated RTI are advocated to maintain a low resistance rate. Penicillin is still the drug of choice in patients without frequent recurrences of RTI in a setting similar to the one studied.

Adolescent↗
PubMed2005

Simultaneous detection of mastitis pathogens, Staphylococcus aureus, Streptococcus uberis, and Streptococcus agalactiae by multiplex real-time polymerase chain reaction.

The objective of this study was to develop a multiplex real-time polymerase chain reaction (PCR) method for simultaneous detection of Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus uberis directly from milk. A genetic marker specific for Staph. aureus was used for primers and dual-labeled probe design. The target for Strep. agalactiae primers and dual-labeled probe was selected from the cfb gene encoding the Christie-Atkins-Munch-Petersen factor. The plasminogen activator gene was the target for primers and dual-labeled probe design for Strep. uberis. Quarter milk samples (n = 192) were analyzed by the multiplex real-time PCR assay and conventional microbiological methods. An additional 57 quarter milk samples were analyzed in a separate real-time PCR assay for Strep. agalactiae only. Using an overnight enrichment step, the real-time PCR technique correctly identified 96.4% of all quarter milk samples; 91.7% of Staph. aureus, 98.2% of Strep. agalactiae, and 100% of Strep. uberis. Results of conventional microbiological methods were used to determine the sensitivity and specificity of the multiplex real-time PCR procedure. The sensitivity of the procedure to correctly identify Staph. aureus, Strep. agalactiae, and Strep. uberis directly from milk was 95.5%, and the specificity was 99.6%. Results of this study indicate that the multiplex real-time PCR procedure has the potential to be a valuable diagnostic technique for simultaneous identification of Staph. aureus, Strep. agalactiae, and Strep. uberis directly from quarter milk samples.

Animals↗
PubMedDate not supplied

[Antimicrobial susceptibility of Streptococcus pyogenes, Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis from community acquired respiratory infections in 2000].

The Viriato Study is a nationwide, multicenter prospective study of the antimicrobial susceptibility of bacterial pathogens commonly associated with community-acquired respiratory tract infections in Portugal. In 2000, 28 laboratories participated in the study with a total of 1071 strains, with testing undertaken in a central laboratory. Of the 213 Streptococcus pyogenes strains isolated from patients with acute tonsillitis, all were susceptible to penicillin, amoxicillin/clavulanate and cefuroxime, but 21.1% were resistant to erythromycin, clarithromycin, azithromycin and 16.4% to tetracycline. From patients with lower respiratory tract infection, 403 strains of Haemophilus influenzae, 366 of Streptococcus pneumoniae and 89 of Moraxella catarrhalis were studied. 13.1% of H. influenzae and 94.4% of M. catarrhalis produced beta-lactamase. Among S. pneumoniae isolates, 25.1% were resistant to penicillin (8.8% showing high-level resistance), 14.5% to tetracycline, 12.8% to erythromycin, clarithromycin and azithromycin, and 10.1% to cefuroxime. Overall, penicillin was the most active antimicrobial against S. pyogenes and amoxycillin/clavulanate the most active in vitro simultaneously against H. influenzae, S. pneumoniae and M. catarrhalis isolated from patients with community-acquired LRTI in Portugal.

Community-Acquired Infections↗
PubMed2003

[Rapid detection of Streptococcus mutans and streptococcus sobrinus in human saliva by nested polymerase chain reaction].

OBJECTIVE: To establish a simple and rapid method to detect Streptococcus mutans and streptococcus sobrinus simultaneously in human saliva. METHODS: Chromosomal DNA from the bacteria was obtained by the extraction method with phenol-chloroform. A nested PCR method with two sets of primers specific for portions of the glucosyltransferase genes (gtfB of S. mutans and gtfI of S. sobrinus), was optimized to detect S. mutans and S. sobrinus from standard strains, clinical strains and directly in human saliva. RESULTS: The first process of nested PCR was capable of amplifying DNA fragments specific for these species from chromosomal DNA extracted from 10(5) CFU cells of standard and clinical strains, or from 1 ml clinical saliva samples containing 10(5) CFU cells of either species. a second process of nested PCR, using the first PCR product as a template with new internal primers to detect 10(3) CFU of either streptococcal species in 1ml saliva samples. CONCLUSION: Nested PCR could detect S. mutans and S. sobrinus rapidly and simply in human saliva. This finding would be important to studies of elucidation the role of these two streptococcal species in the etiology of dental caries.

Humans↗
PubMed2004

Multicenter surveillance of antimicrobial resistance of Streptococcus pyogenes, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis to 14 oral antibiotics.

BACKGROUND AND PURPOSE: Data on the in vitro activities of orally administered cephalosporins, particularly third-generation cephalosporins, against recent pathogens responsible for community-respiratory tract infection are lacking. METHODS: A susceptibility surveillance of 267 isolates of Streptococcus pneumoniae, 205 of Streptococcus pyogenes, 204 of Haemophilus influenzae, and 147 of Moraxella catarrhalis to 14 oral antimicrobial agents using the agar dilution method was carried out from March 2002 to October 2002 in Taiwan. RESULTS: High rates of non-susceptibility to penicillin (60%), cefaclor (67%), cefuroxime (62%), cefpodoxime (64%), clarithromycin (91%), and trimethoprim-sulfamethoxazole (98%) for S. pneumoniae isolates and high rates of non-susceptibility to ampicillin (70%), clarithromycin (34%), and trimethoprim-sulfamethoxazole (63%) for H. influenzae isolates were found. The rank order of oral cephalosporin activity based on the minimum concentrations at which 90% of the isolates were inhibited (MIC90s) for S. pneumoniae was cefpodoxime > cefuroxime > cefixime > cefaclor, cephradine > cephalexin and for H. influenzae and M. catarrhalis was cefixime > cefpodoxime > cefuroxime > cefaclor > cephalexin, cephradine. Among the 75 S. pneumoniae isolates resistant to penicillin (MICs ranged 2 to 4 mg/L), 4% were intermediate to amoxicillin and > 90% were resistant to cefaclor, cefuroxime, and cefpodoxime. For S. pyogenes isolates, all were susceptible to penicillin, 21% were not susceptible to clarithromycin and 4% were not susceptible to clindamycin. Thirty four percent of H. influenzae isolates were not susceptible to clarithromycin. The MIC90 of clarithromycin against M. catarrhalis isolates was 0.5 mg/L. CONCLUSIONS: Cefpodoxime, cefixime, and cefuroxime are promising agents against these bacterial pathogens, except for penicillin-non-susceptible S. pneumoniae isolates.

Anti-Bacterial Agents↗
PubMed1990

Conjugative mobilization of the cloned M6 protein gene from Streptococcus pneumoniae to Streptococcus pyogenes.

The host-vector system omega 6001-pDP36 was used to transfer the M6 protein gene (emm-6.1) of Streptococcus pyogenes to other S. pyogenes strains, isogenic and nonisogenic to D471, the strain from which emm-6.1 was originally cloned. The first step was to subclone emm-6.1 into the insertion vector pDP36. The resulting plasmid, pRMB20, was used as donor in transformation to insert emm-6.1 into the conjugative transposon omega 6001. Streptococcus pneumoniae DP1322, carrying omega 6001 integrated into the chromosome, was the recipient in the transformation experiment. omega 6001 containing emm-6.1 was then transferred by conjugation from S. pneumoniae to the chromosomes of M+ and M- S. pyogenes strains. S. pyogenes transconjugants contained one intact copy of emm-6.1 integrated into the chromosome, but no expression of M6 protein could be detected by Western blot analysis. We found no evidence of the positive transacting regulation of emm gene expression postulated by other authors. In fact, the cloned emm-6.1 was not expressed in three strains expressing their own M proteins (M5, M17 and a shorter M6). In these partial diploids M protein genes were expressed only when present in the original chromosomal locus.

Antigens, Bacterial↗
PubMed1989

[Cariogenicity of Propionibacterium acnes, Streptococcus intermedius and Streptococcus mutans in germ-free rats].

A comparative study has been made on the cariogenic potentials of Propionibacterium acnes ATCC 11828, Streptococcus intermedius OE-1 and Streptococcus mutans OZ-1. The strains of P. acnes and S. intermedius have chondroitinase activity. As metabolic end-products, the P. acnes strain produces mainly a weak acid, propionic acid, whereas strong lactic acid is the main product of the strains of S. intermedius and S. mutans. Five germ-free rats were used for infection with each bacterial strain. The rats were fed with a 25% sucrose diet for 100 days and then sacrificed. The upper and lower molars were used for the determination of the smooth surface caries score. The right upper and lower jaws were used for the preparation of sections which were employed for the determination of the fissure caries score and microradiography. The left upper and lower jaws were decalcified and used for the preparation of thin sections for staining with Gram's, hematoxilin eosin, Mallory's, alcian blue-PAS, silver and toluidine blue stain. The results obtained were as follows: 1. The recoveries of infected cells in the specimens obtained by swabbing the oral cavities were in the order of 10(4) CFU/mg wet weight regardless of the strains injected. 2. Macroscopically, the P. acnes strain decalcified to a lesser extent some of the enamel surfaces of the lower molars. However, the S. intermedius strain produced mainly the fissure caries of the lower molars. The S. mutans strain destroyed the enamel extensively, resulting in the induction of rampant carious lesions. 3. The caries scores of smooth surface determined by Keyes's method were 19.4 +/- 7.8, 46.8 +/- 5.8 and 118.4 +/- 15.4 in the rats infected with the strains of P. acnes, S. intermedius and S. mutans, respectively. The fissure caries score determined by the modified König's method were 8.5, 22.3 and 36.5 in the sections prepared from the rats infected with the strains of P. acnes, S. intermedius and S. mutans, respectively. 4. Microradiography revealed no translucent area in the enamel and dentine of the P. acnes-infected molars, while in the S. intermedius-infected molars translucent areas were found at the dentino-enamel junction neighboring the bottoms of some fissures. The S. mutans-infected molars showed extensive translucent areas over the enamel and dentine of all of the molars. Even defects of the enamel and dentinal areas were observed in some of the molars. 5. The decalcified tooth sections were stained in a similar manner irrespective of the type of organisms used to infect them.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1981

Lethal effect of CAMP-factor and UBERIS-factor--a new finding about diffusible exosubstances of streptococcus agalactiae and Streptococcus uberis.

CAMP-factor, the exosubstance of Streptococcus agalactiae, and UBERIS-factor, the exosubstance of Streptococcus uberis, exerted lethal effect when administered parenterally to rabbits and white mice. A single intravenous dosis of 1,500 activity units per 1 kg body weight resulted in rapid death of the rabbits. To kill mice, the intravenous or intraperitoneal dosis had to be 45 times higher in relation to the body mass. After formaldehyde treatment, both streptococcal exosubstances were deprived of their lethal effect as well as of their synergistic hemolytic activity with the staphylococcal beta-toxin.

Animals↗
PubMed1981

Ultrastructural location of Streptococcus mutans and Streptococcus sanguis antigens in carious human dentine.

The ultrastructural localization of bacterial antigens of Streptococcus sanguis and of the various serotypes a,b,c,d,e,f and g of Streptococcus mutans was studied in human carious dentine using the indirect peroxidase-antiperoxidase method with appropriate controls. No positive staining was seen in adjacent normal dentine. In the inner dentine underlying the cytoplasm of fibroblasts and Schwann cells of unmyelinated nerve fibrils. In sclerosed tubules, or on the plasmalemma of the odontoblast process or on both structures. Only in the odontoblast, facing the carious cone, were dense stainings noted in vacuoles of various sizes located in the Golgi apparatus in juxta-nuclear position and in their odontoblast processes. In pulpal regions, underlying the carious cone, dense vacuoles were also observed in the cytoplasm of fibroblasts and Schwann cells of unmyelinated nerve fibrils. In sclerosed tubules, electron dense deposits were noted in the lumen and the walls of the calcified tubules. In the outer carious dentine, invaded by micro-organisms, positive antigenic stainings were observed in the cell wall and capsular material of a great number of micro-organisms as well as in the interbacterial matrix.

Antigens, Bacterial↗
PubMed1995

Fibronectin binding by Streptococcus milleri group strains and partial characterisation of the fibronectin receptor of Streptococcus anginosus F4.

The Streptococcus milleri group were shown to bind fibronectin (Fn) to their cell-surface and this binding increased the adhesion of cells to hydroxyapatite. The binding of Fn to Streptococcus anginosus F4 was studied in more detail. Fn binding to bacterial cells increased the association of the bacteria with the polymorphonuclear leukocytes obtained from the peritoneal cavity of rats but did not increase killing of the bacteria. The cell-surface receptor was a protein of M(r) 14,000 which was released from cells after mutanolysin digestion. The binding was specific, with cells having a maximum number of binding sites per cell of 770. Electron microscopy, using gold-labelled Fn, localised the receptor to areas between daughter cells.

Animals↗
PubMed1999

Recombinant hyaluronate associated protein as a protective immunogen against Streptococcus equi and Streptococcus zooepidemicus challenge in mice.

The capsule of Streptococcus equi, the cause of strangles, and Streptococcus zooepidemicus, associated with equine lower airway disease, plays an important role in evasion of phagocytosis by polymorphonuclear leucocytes. It is composed of hyaluronate, making it non-immunogenic. A hyaluronate associated protein (HAP) from S. equisimilis, whose gene has been sequenced [1], was investigated (a) for its presence in S. equi and S. zooepidemicus and (b) as an immunogen able to interfere with capsule structure and protect against experimental challenge of mice. The purified capsule of S. equi contained a protein of similar molecular mass to the S. equisimilis protein (approximately 53 kDa). Polymerase chain reaction (PCR) using primers derived from the published sequence of S. equisimilis HAP yielded a product from S. equi and S. zooepidemicus of the expected size and susceptibility to restriction endonucleases. Subcloning of two large in frame StuI/SspI fragments of the HAP gene from S. equi, approximately equivalent to the two halves of the molecule, into the expression vector pGEX-3X yielded only the carboxy half in the correct orientation. This latter recombinant produced a GST fusion protein (HAP-GST) of the expected size that was affinity purified. Antibodies in rabbit antiserum to the native protein in purified hyaluronate reacted strongly in immunoblots with HAP-GST. Antiserum to HAP-GST, when soaked into filter paper strips, caused a diminution of capsule production by S. equi cultured on blood agar. Antiserum added into fresh rabbit blood was not opsonic for S. equi. Immunization with HAP-GST significantly reduced rhinitis in Balb/C mice challenged nasally with S. equi and significantly increased survival time and clearance of bacteria in CBA/CA mice challenged intraperitoneally with S. zooepidemicus.

Animals↗
PubMed1981

Inactivation of D-glucosyltransferases from oral Streptococcus mutans and Streptococcus sanguis by photochemical oxidation.

Cell-free D-glucosyltransferase of D-glucose-grown Streptococcus mutans AHT was completely inactivated in the presence of 0.002% of Methylene Blue at 25 degrees and pH 7.0 after illumination with a 150-W incandescent lamp. The rate of inactivation was decreased at pH values less than 7.0. Histidine was the only amino acid residue modified to a significant extent, and the rates of oxidation of histidine residues and loss of enzyme activity closely agreed. Production of both water-insoluble and -soluble D-glucan fractions from sucrose by the oxidized D-glucosyltransferase preparations was significantly inhibited. Photooxidation with 0.002% of Rose Bengal at pH 7.0 or higher also induced complete inactivation of the D-glucosyltransferase. These results strongly suggest that the imidazole portion of histidine may function as part of the active sites of both D-glucosyltransferase isozymes of S. mutans AHT, which are responsible for the synthesis of (1 goes to 3)- and (1 goes to 6)-alpha-D-glucosidic linkages. The D-glucosyltransferases from S. mutans 6715 and AHT-mutant M1, and Streptococcus sanguis ATCC 10558 were also almost completely inactivated by Methylene Blue-sensitized photooxidation.

Amino Acids↗
PubMed2001

Streptococcus agalactiae and Streptococcus difficile 16S-23S intergenic rDNA: genetic homogeneity and species-specific PCR.

Streptococcus difficile is a non-hemolytic Gram-positive bacterial coccus that causes septicemia and meningoencephalitis in farmed tilapia (Oreochromis sp.) and rainbow trout (Oncorhynchus mykiss). Recent studies have demonstrated S. difficile to be a group B, type Ib streptococcus with a whole cell protein electrophoretic profile indistinguishable from S. agalactiae and a biochemical profile similar to that observed for other group B, type Ib streptococci isolated from fish and frogs. The aim of this study was to expand on these findings by comparative nucleic acid sequence analysis of the 16S-23S ribosomal DNA (rDNA) intergenic spacers of S. difficile and S. agalactiae. The 97.7% sequence homology identified in these studies supports the taxonomic relationship of these two organisms. The sequence data generated were also used to construct a pair of species-specific PCR primers for use in molecular detection and identification schemes.

Animals↗
PubMed2003

Effect of penethamate hydriodide treatment on bacteriological cure, somatic cell count and milk production of cows and quarters with chronic subclinical Streptococcus uberis or Streptococcus dysgalactiae infection.

A randomized, controlled field trial was performed in The Netherlands to determine the therapeutic efficacy of parenteral penethamate hydriodide (Leocillin) against naturally occurring, chronic, streptococcal mastitis during lactation. Quarter milk samples were collected from subclinical cases of Streptococcus uberis or Streptococcus dysgalactiae mastitis to determine the effect of treatment on bacteriological cure and somatic cell count (SCC) at quarter level. A quarter was considered to be cured when the bacterial species, isolated prior to treatment, was not isolated from the quarter milk samples taken on days 10 and 20 post-treatment (bacteriological cure), or when a quarter milk SCC (QMSCC) was <250000 cells/ml on days 10 and 20 post-treatment (SCC cure). Longitudinal data analysis was performed to determine the effect of antibiotic therapy on SCC and milk yield at cow level. Bacteriological cure occurred in 59% of 29 treated quarters, while no cure was observed in any of the 21 untreated control quarters. Treatment resulted in a significant decrease in SCC at cow and quarter level in comparison with untreated controls. There was no significant effect of treatment on milk production. Antibacterial treatment of subclinical streptococcal infections during lactation also prevented clinical mastitis. Furthermore, the treatment may contribute to reduction of bulk milk SCC and to prevention of pathogen spread in dairy herds.

Animals↗
PubMed1992

Complete structure of the adhesin receptor polysaccharide of Streptococcus oralis ATCC 55229 (Streptococcus sanguis H1).

This report describes the determination of the complete primary structure of the adhesin receptor polysaccharide of Streptococcus oralis ATCC 55229 (previously characterized as Streptococcus sanguis H1), a Gram-positive bacteria implicated in dental plaque formation. The polysaccharide was isolated from S. oralis ATCC 55229 cells after deproteination, enzymatic hydrolysis, and ion exchange chromatography. It was shown to consist of rhamnose, galactose, glucose, glycerol, and phosphate, in molar ratios of 2:3:1:1:1. Sequence and linkage assignments of the glycosyl residues were obtained by methylation analysis followed by gas-liquid chromatography and electron-impact mass spectrometry. 31P NMR spectroscopy revealed that phosphate was present in a diester, connecting glycerol to one of the galactosyl residues. High-performance liquid chromatography of a partial acid hydrolysate of the polysaccharide confirmed this finding by showing galactose 6-phosphate and glycerol 1-phosphate. The structural determination was completed by the combination of two-dimensional homonuclear Hartmann-Hahn and NOE experiments and heteronuclear [1H,13C] and [1H,31P] multiple-quantum coherence experiments. Thus, the adhesin receptor polysaccharide of S. oralis ATCC 55229 was found to be a polymer composed of hexasaccharide repeating units that contain glycerol linked through a phosphodiester to C6 of the alpha-galactopyranosyl residue and are joined end-to-end through galactofuranosyl-beta(1-->3)-rhamnopyranosyl linkages: [formula: see text] This structure is novel among bacterial cell surface polysaccharides in general and specifically among those implicated in dental plaque formation.

Bacterial Proteins↗
PubMed1999

Antibacterial synergistic effect of chlorhexidine and hydrogen peroxide against Streptococcus sobrinus, Streptococcus faecalis and Staphylococcus aureus.

Chlorhexidine (CHX) and Hydrogen peroxide (HP) are potent antibacterial agents that are used in controlling dental plaque. However, both agents bear undesired side-effects. We have tested the hypothesis that an antibacterial synergistic effect can occur between the two agents against Streptococcus sobrinus, Streptococcus faecalis and Staphylococcus aureus. We have found that at several combinations of HP and CHX an antibacterial synergistic effect does occur, while at other combinations a on-significant synergism was noticed. No antagonism between the two agents was found in our experimental system. It can be postulated that the mechanism of this synergistic effect is via alteration of the bacterial cell-surface by CHX thereby allowing for an increased amount of HP to penetrate and to react with the intercellular organelles of the bacteria. These results suggest that CHX and HP can be of use in controlling the dental plaque in the oral cavity.

Anti-Infective Agents, Local↗