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PubMed2006

[Bilateral breast bacterial cellulite secondary to Streptococcus agalactiae septicemia].

BACKGROUND: We report a case of group B streptococcal septicemia of digestive origin with secondary bilateral breast dermal-hypodermal localization. CASE REPORT: A 71 year-old woman with a past history of bilateral breast cancer treated by conservation therapy was hospitalized because of the sudden occurrence of two clearly delimited, inflammatory, dermal-hypodermal cutaneous plaques located on each breast, associated with fever (39 degrees C), 4 days after a colonoscopy. Further investigations eliminated carcinomatous mastitis and blood cultures were positive for group B beta-hemolytic streptococcus (Streptococcus agalactiae). Histological examination of a sigmoid polyp revealed a tubular adenocarcinoma. DISCUSSION: We report the first documented case of secondary dermal-hypodermal bacterial skin infection (cellulitis) due to group B beta-hemolytic streptococcus. The occurrence after colonoscopy examination, chronology of clinical features, bilaterality and positive blood cultures are arguments in favor of the secondary nature of the skin infection process.

Adenocarcinoma↗
PubMed1983

Virulent Streptococcus pyogenes: outbreak and spread within a geriatric unit.

An outbreak of infection due to Streptococcus pyogenes occurred in a geriatric rehabilitation unit between February and September 1981, affecting 10 patients and two staff. The severity of the illness ranged from asymptomatic throat carriage, through skin and soft-tissue sepsis, to fulminant septicaemia and necrotising fasciitis: two patients died of their infection. Streptococcus pyogenes infection may present in a variety of ways, and may be dangerous. Recently developed serological tests have been found useful in the surveillance of an outbreak. Although Streptococcus pyogenes is sensitive to penicillin and other antibiotics, good ward hygiene is still essential for controlling such an outbreak in an institution.

Aged↗
PubMed2003

Rapid detection and identification of Streptococcus macedonicus by species-specific PCR and DNA hybridisation.

The aim of this study was to develop a simple and specific method for the rapid detection and identification of Streptococcus macedonicus. The method was based on polymerase chain reaction (PCR) using species-specific primers derived from the 16S rRNA gene. Specific identification was proven on seven S. macedonicus strains, while 16 strains belonging to different lactic acid bacteria species were tested negative. The PCR assay was capable of detecting 100 pg of S. macedonicus DNA, and it was also efficient on single colonies of the bacterium. Furthermore, the same bacterial strains were used for the specificity evaluation of a S. macedonicus species-specific probe. Neither species-specific PCR nor DNA hybridisation experiments could differentiate Streptococcus waius from S. macedonicus, due to the identity of the 16S rRNA gene of the two species, indicating high phylogenetical relatedness. This was further confirmed by the comparative sequence analysis of the 16S-23S rRNA intergenic regions. It was thus clearly demonstrated that S. waius, recently described as a novel Streptococcus species, is phylogenetically identical to S. macedonicus.

Bacterial Typing Techniques↗
PubMed1992

Fatal peritonitis due to group B beta-hemolytic streptococcus in a patient receiving chronic ambulatory peritoneal dialysis.

Peritonitis in continuous ambulatory peritoneal dialysis (CAPD) patients is rarely caused by group B beta-hemolytic streptococcus species. We describe a 52-year-old man with chronic glomerulonephritis who developed a fatal peritonitis due to streptococcus group B in the absence of predisposing factors such as diabetes mellitus, malignancy, human immunodeficiency virus (HIV) infection, or liver disease. This report suggests that although beta-hemolytic streptococcus is a rare cause of peritonitis, the severity of the infection may be overwhelming and may rapidly lead to serious consequences and death.

Humans↗
PubMed1998

Potential virulence factors of Streptococcus dysgalactiae associated with bovine mastitis.

Mastitis caused by environmental pathogens is a major problem that affects many well-managed dairy herds. Among the environmental pathogens, Streptococcus dysgalactiae is isolated frequently from intramammary infections during lactation and during the nonlactating period. In spite of its high prevalence, little is known about factors that contribute to the virulence of S. dysgalactiae. During the last decade, several cell-associated and extracellular factors of S. dysgalactiae have been identified; yet, the relative importance of these factors in the transmission and pathogenesis of mastitis caused by S. dysgalactiae has not been defined. Streptococcus dysgalactiae can interact with several plasma and extracellular host-derived proteins such as immunoglobulin G, albumin, fibronectin, fibrinogen, collagen, vitronectin, plasminogen, and alpha 2-macroglobulin. These interactions are mediated by bacterial surface proteins. This organism also produces hyaluronidase and fibrinolysin which may be involved in promoting dissemination of the organism into host tissue. Streptococcus dysgalactiae adheres to and is internalized by bovine mammary epithelial cells in vitro. Involvement of host cell kinases, intact microfilaments and de novo eukaryotic protein synthesis are required for internalization of S. dysgalactiae into bovine mammary epithelial cells; a process that appeared to occur by a receptor-mediated endocytosis mechanism. However, de novo bacterial protein synthesis was not required for epithelial cell internalization. Furthermore, S. dysgalactiae survived within mammary epithelial cells for extended periods of time without losing viability or damaging the eukaryotic cell. Further research on characterization of host-pathogen interactions that take place during the early stages of mammary gland infection will enhance our understanding of pathogenesis of intramammary infection which may contribute to development of methods to minimize production losses due to mastitis.

Animals↗
PubMed2000

Taxonomic study of "tufted mitior" strains of streptococci (Streptococcus sanguinis biotype 11); recognition of a new genospecies.

The taxonomic position of tufted strains of streptococci, phenotypically resembling Streptococcus mitis and previously referred to as 'tufted mitior' was investigated. By 16S rRNA sequence analysis, it was clear that the "tufted mitior" strains belonged to the mitis group of species within the genus Streptococcus. It was confirmed that these strains were taxonomically independent at the species level, sharing less than 43%, DNA-DNA similarity with all established species of the mitis group. However biochemical test data obtained, using three commercial identification kits (Rapid ID32 Strep, STREPTOGRAM, and Biolog GP-plate) together with in-house biochemical tests employing 4-MUF-linked fluorogenic substrates did not reveal sufficient differential tests with which to identify the "tufted mitior" strains unequivocally. From these data, we conclude that these "tufted mitior" strains represent a new taxon within the mitis group of the genus Streptococcus, and propose that they should be considered as a genospecies until differential phenotypic characteristics are found for their identification.

Bacterial Typing Techniques↗
PubMed1990

[Fatal maternal streptococcus A infection after cesarean section].

A case is reported of an infection with Streptococcus pyogenes, occurring 24 hours after an elective Caesarean section in a 30 year old woman. She worsened during the first 48 h, with shock (Pasys less than 70 mmHg, pH 7.28) as well as abdominal tenderness and guarding. Laparotomy revealed peritonitis, and subtotal hysterectomy was carried out. Gram positive cocci were found in the peritoneal exudate, with bacterial cultures yielding Streptococcus pyogenes. Histopathological examination of the specimen revealed necrosing endomyometritis with septic thrombophlebitis. During the immediate post-operative period, there were several prolonged episodes of circulatory arrest treated with dobutamine, adrenaline, and noradrenaline. Multiple organ failure occurred during the next five days, despite antibiotic therapy (vancomycin, tienamycin, amikacin) and intensive care. It included jaundice, thrombocytopaenia (10 G.l(-1] adult respiratory distress syndrome (ARDS). A further laparotomy was carried out because of abdominal and thigh cellulitis, with completion of the hysterectomy and bilateral salpingo-oophorectomy. Streptococcus pyogenes was still present in the peritoneal cavity. There followed an improvement, with a return to normal of the platelet count, haemodynamic stability such that vasoactive drugs were no longer needed, and a decrease in the degree of jaundice. However, the ARDS worsened, and the patient died 15 days after the Caesarean section. There have been recent reports of similar cases, suggesting an increase in the virulence of group A streptococci linked to a re-emergence of exotoxin A.

Adult↗
PubMed2002

Identification of streptococcus mitis group species by RFLP of the PCR-amplified 16S-23S rDNA intergenic spacer.

Mitis group streptococci are pioneer colonizers of tooth surfaces and are implicated in various pathologies. Thus, accurate identification of oral mitis group strains would be valuable for studies of plaque ecology and dental caries and for diagnostic use in endocarditis or sepsis patients. The aim of this study was to evaluate the usefulness of PCR-RFLP analysis of the 16S-23S intergenic spacer for differentiating and identifying streptococcus mitis group species. The 16S-23S rDNA spacer regions of 27 type and reference Streptococcus strains, representing 8 species, were studied by PCR-mediated amplification by using oligonucleotide primers FGPS 1490-72 and FGPL 132'-38. PCR products were digested, independently, with 14 restriction enzymes. Only AluI, MboI, CfoI, HinfI and MaeII distinguished some species, particularly AluI and CfoI, but not all the species. Eight clusters were clearly generated, corresponding to currently recognized species, but only with the addition of five ITS restriction patterns, generated by AluI + MboI + CfoI + HinfI + MaeII, then clustered by UPGMA, on a distance consensus matrix. The combination of these five ITS RFLP tests allowed a relatively conclusive genomic group differentiation of mitis group species. Despite this observation, more strains of each species will need to be analyzed, particularly clinical isolates, before arriving at general conclusions about the utility of ITS restrictions for identification of strains at the species level. An ITS PCR-RFLP-based identifying method for streptococcus mitis group species would provide significant advantages over other molecular taxonomic methods which require DNA extraction and DNA-DNA hybridization.

DNA, Ribosomal Spacer↗
PubMed2002

Clinical aspects and cost of invasive Streptococcus pneumoniae infections in children: resistant vs. susceptible strains.

Invasive Streptococcus pneumoniae infections in children are associated with serious consequences in terms of morbidity and mortality. The main objective of the study was to determine if invasive infections caused by penicillin-resistant Streptococcus pneumoniae (PRSP) differed in clinical presentation, outcome, risk factors, or cost from those caused by penicillin-susceptible strains (PSSP) in children. All patients aged 18 or less with invasive Streptococcus pneumoniae infections admitted to two teaching hospitals in Montreal between 1989 and 1998 were included in the study. We present a case-control study in which for each index case of PRSP, 3 controls with PSSP infections were matched for age, sex, and site of infection. One hundred and forty-four patients were included in the analysis (36 cases, 108 controls). There was no difference between the two groups in terms of initial clinical presentation (vital signs, laboratory results) or total length of stay. Mortality was 2.7% in both groups. Hospital antibiotic cost was higher in the PRSP group (211 Canadian dollars (CAD) vs. 74 CAD; P=0.02). Antibiotic consumption in the preceding month was significantly associated with PRSP infection. Underlying diseases or day-care attendance were not shown to be significant risk factors for acquiring invasive PRSP infection. There were no differences between invasive infections caused by PRSP and PSSP in terms of clinical presentation, morbidity or mortality in a paediatric population.

Adolescent↗
PubMedDate not supplied

Prevalence of Streptococcus pyogenes as an oropharynx colonizer in children attending daycare: a comparative study of different regions in Brazil.

UNLABELLED: Thirty percent of acute pharyngotonsillitis is caused by Streptococcus pyogenes, which increased the risk of glomerulonephritis and rheumatic fever. Children attending daycare centers have a higher incidence of these infections. AIM: to identify and compare the prevalence of Streptococcus pyogenes in the oropharynx of children who are enrolled and who are not enrolled in daycare centers in different regions of Brazil. MATERIALS AND METHODS: A prospective study of two hundred children from Sao Paulo/SP and Porto Velho/RO. Children from each city were divided into two groups: those attending, and those not attending daycare centers. Swabs of the oropharynx were taken for bacteriological culture and identification. RESULTS: The prevalence of Streptococcus pyogenes in the Sao Paulo groups were 8% and 2% for daycare and control groups, which was statistically significant (p=0.02). The prevalence in children from Porto Velho/RO was 24% and 16% for daycare and control groups, which was statistically significant (p=0.015). Statistical analysis also showed a significant difference between the corresponding groups in the two locations (p<0.01). CONCLUSION: These results show that daycare attendance is a risk factor for oropharyngeal streptococcal colonization; this was seen in different populations, but was statistically significance in only one of the two samples.

Brazil↗
PubMed2002

Streptococcus pyogenes prtFII, but not sfbI, sfbII or fbp54, is represented more frequently among invasive-disease isolates of tropical Australia.

Streptococcus pyogenes (group A streptococcus) strains may express several distinct fibronectin-binding proteins (FBPs) which are considered as major streptococcal adhesins. Of the FBPs, SfbI was shown in vitro to promote internalization of the bacterium into host cells and has been implicated in persistence. In the tropical Northern Territory, where group 4 streptococcal infection is common, multiple genotypes of the organism were found among isolates from invasive disease cases and no dominant strains were observed. To determine whether any FBPs is associated with invasive disease propensity of S. pyogenes, we have screened streptococcal isolates from bacteraemic and necrotizing fasciitis patients and isolates from uncomplicated infections for genetic endowment of 4 FBPs. No difference was observed in the distribution of sfbII, fbp54 and sfbI between the blood isolates and isolates from uncomplicated infection. We conclude that the presence of sfbI does not appear to promote invasive diseases, despite its association with persistence. We also show a higher proportion of group A streptococcus strains isolated from invasive disease cases possess prtFII when compared to strains isolated from non-invasive disease cases. We suggest that S. pyogenes may recruit different FBPs for different purposes.

Adhesins, Bacterial↗
PubMed2000

Genetic transformation in Streptococcus mutans requires a peptide secretion-like apparatus.

Competence for genetic transformation in Streptococcus pneumoniae and Streptococcus gordonii involves the ComAB secretion apparatus, which is thought to export the competence-stimulating peptide. Homologous secretory systems are also used for the export of certain bacteriocins and bacteriocin-like peptides. In this study, a similar secretory apparatus was found in the Streptococcus mutans genome, and its role in transformation was investigated. Gene inactivation resulted in a mutant deficient in transformability. We suggest that secretion of a peptide, possibly the competence-stimulating peptide itself, is involved in competence induction also in S. mutans.

ATP-Binding Cassette Transporters↗
PubMed1998

Random amplified polymorphic DNA and amplified ribosomal DNA spacer polymorphism: powerful methods to differentiate Streptococcus thermophilus strains.

Streptococci from different collections and dairy materials were characterized by conventional and molecular methods. After amplification of the 16S-23S rDNA spacer region, all the strains referable to the genus Streptococcus exhibited a single polymerase chain reaction (PCR) product, allowing their differentiation from enterococci. Cleaving this PCR product with Hae III, two different restriction patterns could be observed, allowing Streptococcus salivarius DSM 20560T, Strep. thermophilus NCDO 822 and two strains of Streptococcus spp. to be gathered in one group and all the other strains in another. In order to achieve strain typing, all the cultures were investigated by random amplified polymorphic DNA (RAPD)-PCR analysis employing two selected primers. The results were treated by cluster analysis, appearing significantly consistent with both the taxonomic position and the origin of the strains. Pulsed-field gel electrophoresis (PFGE) of Sma I digests of the genomic DNA from 11 representative strains with decreasing levels of RAPD similarity allowed their diversity to be confirmed, even though RAPD-PCR proved to be less discriminating than PFGE analysis. The results are discussed with reference to the capability of the analytical procedures used to aid both identification and strain typing of streptococci, as well as the taxonomic structure of the species Strep. thermophilus.

Bacterial Typing Techniques↗
PubMed2002

Isolation and characterization of a mutant strain of Streptococcus uberis, which fails to utilize a plasmin derived beta-casein peptide for the acquisition of methionine.

AIMS: To isolate and characterize a mutant of Streptococcus uberis strain 0140J which fails to utilize a plasmin derived beta-casein peptide for the acquisition of methionine. METHODS AND RESULTS: Random insertional mutagenesis was used to isolate a mutant strain of Strep. uberis 0140J which was unable to utilize methionine from within a casein-derived peptide. The altered gene in the mutant strain showed homology to an oligopeptide permease gene of Streptococcus pyogenes (oppF). The mutant was unable to obtain specific amino acids from defined peptides of various lengths and its growth yield in skimmed milk was between 1 and 10% that of the wild-type strain, but was restored following the inclusion of these amino acids. CONCLUSIONS: The oligopeptide permease homologue of Strep. uberis 0140J is necessary for the utilization of amino acids from within specific peptides. Efficient acquisition of essential amino acids by Strep. uberis 0140J is required for the bacterium to achieve an optimum yield in milk. SIGNIFICANCE AND IMPACT OF THE STUDY: Streptococcus uberis is a major agent of bovine mastitis with a corresponding high economic loss. By targeting metabolic pathways essential to the growth of Strep. uberis it may be possible to prevent the establishment of growth of the bacterium in milk. This study has identified the acquisition of essential amino acids as playing a role in the growth of Strep. uberis in milk.

Animals↗
PubMed1996

Protein F2, a novel fibronectin-binding protein from Streptococcus pyogenes, possesses two binding domains.

Binding of the group A streptococcus (GAS) to respiratory epithelium is mediated by the fibronectin (Fn)-binding adhesin, protein F1. Previous studies have suggested that certain GAS strains express Fn-binding proteins that are different from protein F1. In this study, we have cloned, sequenced, and characterized a gene (prtF2) from GAS strain 100076 encoding a novel Fn-binding protein, termed protein F2. Insertional inactivation of prtF2 in strain 100076 abolishes its high-affinity Fn binding. prtF2-related genes exist in most GAS strains that lack prtF1 (encoding protein F1) but bind Fn with high affinity. These observations suggest that protein F2 is a major Fn-binding protein in GAS. Protein F2 is highly homologous to Fn-binding proteins from Streptococcus dysgalactiae and Streptococcus equisimilis, particularly in its carboxy-terminal portion. Two domains are responsible for Fn binding by protein F2. One domains (FBRD) consists of three consecutive repeats, whereas the other domain (UFBD) resides on a non-repeated stretch of approximately 100 amino acids and is located 100 amino acids aminoterminal of FBRD. Each of these domains is capable of binding Fn when expressed as a separate protein. In strain 100076, protein F2 activity is regulated in response to alterations in the concentration of atmospheric oxygen.

Adhesins, Bacterial↗
PubMed1998

Structure of the has operon promoter and regulation of hyaluronic acid capsule expression in group A Streptococcus.

Group A streptococcal strains vary widely in the amount of hyaluronic acid capsule they produce, although the has operon, which encodes the enzymes required for hyaluronic acid synthesis, is highly conserved. The three genes making up the has operon are transcribed from a single promoter located upstream of the first gene in the operon, hasA. To investigate transcriptional regulation of capsule synthesis, we studied the structure and function of the has operon promoter sequences from two strains of group A Streptococcus: a highly encapsulated M-type 18 strain and a poorly encapsulated M-type 3 strain. Transcriptional fusions of the has operon promoter to a promoterless chloramphenicol acetyltransferase gene were constructed in a temperature-sensitive shuttle vector. The influence of promoter structure on has operon transcription was reflected by chloramphenicol acetyl transferase activity in cell lysates of Escherichia coli harbouring the recombinant plasmids and in group A Streptococcus after integration of the promoter fusions into the streptococcal chromosome. Fusions including as few as 12 nucleotides upstream from the -35 site of the has promoter exhibited full activity, indicating that sequences further upstream do not affect has gene transcription. A transcriptional fusion of the has promoter from the highly encapsulated M-type 18 strain was threefold more active than a similar construct from the poorly encapsulated M-type 3 strain. Analysis of the promoter sequences for the two strains revealed differences in three nucleotides in the -35, -10 spacer region of the promoter and in four nucleotides in the +2 to +8 positions relative to the start site of hasA transcription. To determine the relative importance of the two groups of nucleotide substitutions, chimeric promoter sequences were constructed in which either of the two clusters of variant nucleotides from the M18 has promoter was substituted for the corresponding positions in the M3 has promoter. Analysis of these chimeric promoter fusions showed that sequence changes in both regions influenced promoter strength. These results define the limits of cis-acting chromosomal sequences that influence transcription of the has operon and indicate that the fine structure of the promoter is an important determinant of capsule gene expression in group A Streptococcus.

Bacterial Capsules↗
PubMed1999

The R28 protein of Streptococcus pyogenes is related to several group B streptococcal surface proteins, confers protective immunity and promotes binding to human epithelial cells.

The R28 protein is a surface molecule expressed by some strains of Streptococcus pyogenes (group A streptococcus). Here, we present evidence that R28 may play an important role in virulence. Sequence analysis demonstrated that R28 has an extremely repetitive sequence and can be viewed as a chimera derived from the three surface proteins Rib, alpha and beta of the group B streptococcus (GBS). Thus, the gene encoding R28 may have originated in GBS. The R28 protein promotes adhesion to human epithelial cells, as shown by experiments with an R28-negative mutant and by the demonstration that antibodies to highly purified R28 inhibited adhesion. In a mouse model of lethal intraperitoneal S. pyogenes infection, antibodies to R28 conferred protective immunity. However, the virulence of an R28-negative mutant was similar to that of the parental strain in the intraperitoneal infection model. Together, these data indicate that R28 represents a novel type of adhesin expressed by S. pyogenes and that R28 may also act as a target for protective antibodies at later stages of an infection. We consider the hypothesis that R28 played a pathogenetic role in the well-known epidemics of childbed fever (puerperal fever), which were caused by S. pyogenes. A role for R28 in these epidemics is suggested by epidemiological data.

Animals↗
PubMed2001

A secondary RNA polymerase sigma factor from Streptococcus pyogenes.

The important human pathogen Streptococcus pyogenes (the group A streptococcus or GAS) causes diseases ranging from mild, self-limiting pharyngitis to severe invasive infections. Regulation of the expression of GAS genes in response to specific environmental differences within the host is probably key in determining the course of the infectious process, however, little is known of global regulators of gene expression in GAS. Although secondary RNA polymerase sigma factors act as global regulators of gene expression in many other bacteria, none has yet been isolated from the GAS. The newly available GAS genome sequence indicates that the only candidate secondary sigma factor is encoded by two identical open reading frames (ORFS). These ORFS encode a protein that is 40% identical to the transcription factor ComX, believed to act as an RNA polymerase sigma factor in Streptococcus pneumoniae. To test whether the GAS ComX homologue functions as a sigma factor, we cloned and purified it from Escherichia coli. We found that in vitro, this GAS protein, which we call sigmaX, directed core RNA polymerase from Bacillus subtilis to transcribe from two GAS promoters that contain the cin-box region, required for transcription by S. pneumoniae ComX in vivo. On the other hand, GAS sigmaX did not promote transcription of a GAS promoter (hasA) expected to be dependent on sigmaA, the housekeeping or primary RNA polymerase sigma factor. Addition of monoclonal antibody that inhibited sigmaA-directed transcription had no effect on sigmaX-directed transcription, showing that the latter was not the result of contaminating sigmaA. Transcription of both cin-box-containing promoters initiated downstream of the cin-box and two different single basepair substitutions in the cin-box of the cinA promoter each caused a severe reduction of sigmaX-directed transcription in vitro. Thus, the cin-box is required for sigmaX-directed transcription.

Bacillus subtilis↗