Streptococcus Equisimilis Research Articles

Influence of age on neutrophil function in foals

Functional activities (phagocytosis and killing) of neutrophil leucocytes (NL) and immunoglobulin G concentrations were evaluated in six healthy foals from birth to 6 months of age. Peripheral blood NL were reacted with Streptococcus equisimilis in 20 per cent pooled equine serum for 30, 60 and 90 mins and functional activities of NL were determined using a fluorochrome microassay. Values for foal NL function were compared with those of healthy adult horses (n = 28). Foal neutrophil function was influenced by age. Killing capacity of NL decreased, whereas phagocytic capacity increased, until 113 days of age, after which a reversal in trends became apparent. Immunoglobulin G concentrations changed significantly over time and were lowest at 29 to 56 days of age. All foal values for NL function fell within the range of normal values established for healthy adult horses.

Beta-D-glucuronidase activity assay for rapid differentiation of species within beta-haemolytic group C and G streptococci.

Methylumbelliferyl-conjugated enzyme substrates were assessed for their ability to differentiate beta haemolytic streptococci in Lancefield groups C and G. Both Streptococcus equisimilis (group C) and large colony human biotype group G strains were consistently differentiated from group C and G "Streptococcus milleri group" bacteria by their ability to hydrolyse the beta-D-glucuronide substrate. The test was completed in less than one hour.

Beta-haemolytic non-group A streptococci and pharyngitis: A case-control study

A case-control study was conducted to examine the association of beta-haemolytic non-group A streptococci and pharyngitis in a paediatric population (n = 502). No association could be found between disease and traditional Lancefield groups B, C, F, or G. When the analysis included the clustering of genetically related subgroups from different Lancefield groups, an association was evident for moderate and heavy quantitations of beta-haemolytic "large colony" group C and G streptococci (Streptococcus equisimilis and human biotypes of large colony group G streptococci) (p = 0.021). This study further defines a subset of the beta-haemolytic non-group A streptococci that merit recognition by both the laboratory and physician.

Group C Streptococcal Bacteremia: Analysis of 88 Cases

Eighty-eight cases of group C streptococcal bacteremia were reviewed retrospectively. Most patients had underlying diseases (72.7%), predominantly cardiovascular disease (20.5%) or malignancy (20.5%). The infection originated most often from the upper respiratory tract (20.5%), the gastrointestinal tract (18.2%), or the skin (17.1%). Prior exposure to animals or animal products was reported in 23.9% of cases. The most common clinical manifestations of group C streptococcal bacteremia were endocarditis (27.3%), primary bacteremia (22.7%), and meningitis (10.2%). Of streptococcal isolates, 61.4% were not speciated, 19.3% were Streptococcus equisimilis, 17.1% were Streptococcus zooepidemicus, and two (2.3%) were Streptococcus equi. The isolates were sensitive to most antibiotics, and most patients were treated with beta-lactam agents. Mortality was high (25.0%), especially among older patients and patients with endocarditis, meningitis, and disseminated infection. Group C streptococcal bacteremia does not differ from bloodstream infection caused by other beta-hemolytic streptococci with regard to clinical presentation, treatment, or outcome.

高齢者と小児の正常咽頭および腸管溶血レンサ球菌保菌状態の比較

A marked difference between the aged and children has been observed in the group distribution of hemolytic streptococci isolated from various clinical specimens. Group B strains from the urine and sputum, and group G from the sputum, pus and exudate have been predominant in the aged, whereas group A strains from the throat swab have dominated in children. The present study was undertaken to clarify the background for such a marked difference by investigating the normal state of pharyngeal and intestinal carriage of hemolytic streptococci both in the aged and children. 1. As to the pharyngeal carriage, quite a contrast was observed between the aged and children. In the former, the rate of carries was low and the predominant groups among the streptococcus isolates were B (Streptococcus agalactiae) and G (identified as Streptococcus equisimilis), while in the latter, the rate was high and group A (Streptococcus pyogenes) strains comprised approximately 75% of the isolates, most of them being from the throat swab. 2. Both the aged and children showed a similar state of streptococcus carriage in the intestine. The rate of carriers was low and the predominant group among the isolates was B in both populations. Although group G strains were occasionally isolated, group A strains were isolated neither in the aged nor in children. These results explain well the difference between the aged and children in the group distribution of the clinical isolates of hemolytic streptococci.

Duplication of the streptokinase gene in the chromosome ofStreptococcus equisimilisH46A

The erythromycin resistance plasmid pSM752 carrying the cloned streptokinase gene, skc, was introduced by protoplast transformation into Streptococcus equisimilis H46A from which skc was originally cloned. Cells transiently supporting the replication of pSM752 gave rise to an erythromycin-resistant clone designated H46SM which was plasmid free and produced streptokinase at levels approximately twice as high as the wild type. Southern hybridization of total cell DNA with an skc-containing probe provided evidence for the duplication of the skc gene in the H46SM chromosome. The results, which have some bearing on industrial streptokinase production, can be best explained by a single cross-over event between the chromosome and the plasmid in the region of shared homology leading to the integration of pSM752 in a Campbell-like manner.

Duplication of the streptokinase gene in the chromosome of Streptococcus equisimilis H46A

The erythromycin resistance plasmid pSM752 carrying the cloned streptokinase gene, skc, was introduced by protoplast transformation into Streptococcus equisimilis H46A from which skc was originally cloned. Cells transiently supporting the replication of pSM752 gave rise to an erythromycin-resistant clone designated H46SM which was plasmid free and produced streptokinase at levels approximately twice as high as the wild type. Southern hybridization of total cell DNA with an skc-containing probe provided evidence for the duplication of the skc gene in the H46SM chromosome. The results, which have some bearing on industrial streptokinase production, can be best explained by a single cross-over event between the chromosome and the plasmid in the region of shared homology leading to the integration of pSM752 in a Campbell-like manner.

Group C Streptococcal Arthritis: Case Report and Review

Streptococci account for approximately 15%-20% of cases of nongonococcal septic arthritis. The majority of these are due to group A streptococci, but group B and group G streptococci are being isolated more frequently. We present a case of group C streptococcal arthritis and summarize nine additional cases reported in the literature. The group C streptococci include the large colony of Voges-Proskauer-negative bacteria (Streptococcus equi, Streptococcus equisimilis, Streptococcus zooepidemicus, and Streptococcus dysgalactiae) as well as as the minute colony of Voges-Proskauer-positive Streptococcus anginosus ("Streptococcus milleri") group C organisms. Any joint may become infected, but joints affected by preexisting rheumatologic abnormalities are more frequently involved. Bacteremia was documented in five of the 10 patients. One patient had an associated pneumonia, and another patient had an associated acute aortic valve endocarditis. None of the infections involved a prosthetic joint or an overlying cellulitis, associations reported for group G streptococcal arthritis. Surgical drainage of the infected joint was required in six of the 10 patients. We concluded that the presence of two groups of organisms sharing the same Lancefield group antigen necessitates the careful identification of isolates to determine potential clinical differences.

Vaccination of horses against microbial infections: vaccine production against Streptococcus equisimilis, Streptococcus zooepidemicus, Streptococcus equi and horse influenza virus

Vaccination of horses against microbial infections: vaccine production against Streptococcus equisimilis, Streptococcus zooepidemicus, Streptococcus equi and horse influenza virus

The presence of M proteins in outbreak strains of Streptococcus equisimilis T-type 204

Cultures of Streptococcus equisimilis (Lancefield group C) from three outbreaks of illness were found to carry the T-protein antigen 204. Strains of this type were not otherwise represented in a collection of 743 cultures of these 'pyogenes-like' streptococci isolated from other outbreaks of infection or as random isolates. Two of the three outbreaks were of pharyngitis. The third arose in a maternity unit where the organism was isolated from mothers with puerperal fever, from staff and also from the environment. Representative strains were found to carry M-protein antigens as judged by their ability to survive and multiply in fresh normal human blood. Comparison of absorbed rabbit antiserum to the M antigens in opsonic and precipitin tests showed that a distinct M antigen was present on isolates from one outbreak of sore throat and that all cultures from the other two incidents shared a common M antigen. Samples of serum were also available from patients in the outbreak of puerperal sepsis. Most patients developed antibodies to one or more streptococcal antigens including the M protein, streptolysin O, streptokinase and the hyaluronidase specific for strains of group C and group G streptococci.

Outbreaks of human infection caused by pyogenic streptococci of Lancefield groups C and G.

Within a collection of 749 strains of group C streptococci (Streptococcus equisimilis) and 2348 of group G, isolated over a period of 6 years, there were clusters from 63 probable outbreaks of infection. These occurred in burns and maternity units, hospital wards, outpatient clinics, army camps and religious communities. Overall, it was possible to identify T-protein antigens in 88% of the group C strains and in 82% of group G. Serotyping by the identification of T-protein antigens was a useful method for the subdivision of these strains.

An outbreak of puerperal fever caused by group C streptococci

Between 19 February and 18 April 1987, 33 confirmed cases of puerperal fever caused by Streptococcus equisimilis serotype T204 occurred at three hospitals in and around Chelmsford. Most of the cases (70%) occurred on one ward, in which toilet seats and a shower are believed to have aided transmission, although insufficient data were obtained to exclude a role for person-to-person spread. Possession of M-protein antigen was demonstrated in the outbreak strain.

Sequence-directed DNA bending upstream of the streptokinase promoter.

A 450-base pair (bp) HinfI restriction fragment from the chromosome of Streptococcus equisimilis H46A contains the early coding region of the streptokinase gene (skc), the skc promoter, and a stretch of DNA 5' to the--35 region of the skc promoter. Two-dimensional polyacrylamide (PA) gel electrophoresis at two different temperatures showed that this fragment migrates anomalously slowly on PA gels, suggesting the existence of a bent DNA conformation. Inspection of the nucleotide sequence confirmed this suggestion by revealing numerous oligomeric dA.dT tracts, some of which are in phase with the helix screw. Computer analysis of the sequence predicted the existence of two bending loci, one of which is located upstream of the skc promoter. In addition to showing DNA bending, the 450-bp HinfI fragment contains multiple 13-bp sequences homologous to the Escherichia coli integration host factor DNA-binding consensus sequence. Insertion of IS1 into a site immediately upstream of the--35 region decreased the expression level of skc in E. coli, suggesting that DNA conformation upstream of the promoter has a role in skc expression.

Tripartite streptokinase gene fusion vectors for gram-positive and gram-negative procaryotes

A specific 1,596 bp HincII fragment ('skc) from the chromosome of Streptococcus equisimilis contains an active streptokinase (SK) gene (skc) lacking, in addition to the expression signals, codons 1 through 39 of wild-type skc but retaining the remainder of the skc coding sequence together with the transcription terminator. Using this fragment as an indicator gene, we constructed two types of vectors which in appropriate hosts resulted in the synthesis of SK fusion proteins after insertional activation of 'skc. The first type are open reading frame (ORF) vectors in which 'skc was inserted into pUC18 out of frame with respect to lacZ', thus conferring an SK-negative phenotype. Any DNA fragments representing ORFs inserted between the lacZ' expression signals and 'skc such that the skc reading frame was restored resulted in the production of tripartite proteins which exhibited SK activity. The second type of vector, which functioned in both gram-positive and gram-negative bacteria, used the streptococcal speA expression and secretion signals in front of the ORF to activate 'skc insertionally. Using a large fragment from the chymosin gene as the target sequence, the usefulness of these vectors for studying foreign gene expression in streptococci as well as Escherichia coli was demonstrated.

Extraction of group C streptococcal IgG-binding receptor and characterization of the active peptides by Western blotting and isoelectric focusing

Three different enzymatic extraction procedures were tested for their effectivity in releasing IgG-binding peptides from the streptococcal cell wall. Streptococcus equisimilis strain 12628 isolated from pig was incubated with phage-associated lysin, trypsin and Streptomyces globisporus lytic enzyme and the extracts were investigated by Western blotting, indirect erythrocyte agglutination and Ouchterlony diffusion for IgG-binding activity. With all treatments IgG-binding peptides were extracted. However, no homogenous IgG-binding material was released by the enzymes tested. In each case a multiple peptide pattern with IgG-binding activity was found. The molecular weights of the active peptides released also differed between the extraction procedures. The isoelectric points between 4.0 and 4.3 of IgG-binding components were found to be similar for all three extracts.

Human Fc(gamma) receptors for differentiation in throat cultures of group C "Streptococcus equisimilis" and group C "Streptococcus milleri".

The biochemical characteristics and the presence of human Fc(gamma) receptors of 52 throat isolates of group C beta-hemolytic streptococci were examined. Among these isolates, 38 were identified as "Streptococcus milleri" and 14 were identified as "Streptococcus equisimilis." The differentiation of group C "S. equisimilis" from "S. milleri" with identical group antigens was easy to perform by the measurement of the size of the hemolytic zone on a sheep blood agar plate in an anaerobic atmosphere and by biochemical tests (Voges-Proskauer test). A clear-cut criterion for differentiation was noted among these isolates, i.e., the presence of Fc(gamma) receptors. "S. equisimilis," which are generally associated with pharyngitis, possess human Fc(gamma) receptors, while "S. milleri", which are generally isolated from healthy persons, have no such receptors.

Effects of discharged fraction in repeated batch culture for hyaluronate lyase production

The production of hyaluronate lyase (EC 4.2.21), HL, by Streptococcus equisimilis strain SHL-03 has been studied in repeated batch culture with various harvest volumes (discharged fraction, α = 0.875, 0.75, 0.625, and 0.50). The optimum discharged fraction to obtain the highest production was α = 0.75. The productivity of this system was 73% higher than that of a classical batch culture. The process could be repeated for 15 cyclase (245 h) with stable hyaluronate lyase production rate and yield. These results suggest that this system could provide a practical procedure to increase the productivity of an industrial plant without changes in facilities and with minimal investment.

Incidence and characterization of beta-hemolytic Streptococcus milleri and differentiation from S. pyogenes (group A), S. equisimilis (group C), and large-colony group G streptococci.

The biochemical characteristics of 172 clinical isolates of group A, C, F, or G or "nongroupable" beta-hemolytic streptococci were examined. Among these isolates, 91 were identified as beta-hemolytic strains of Streptococcus milleri. The remaining isolates included 20 Streptococcus pyogenes, 21 Streptococcus equisimilis, 37 large-colony group G streptococci, and 3 unidentified nongroupable isolates. A majority (84%) of the S. milleri strains possessed Lancefield group antigen (3 A, 27 C, 41 F, and 5 G), whereas 15 S. milleri strains (16%) were nongroupable. Serological tests did not differentiate S. milleri isolates with group A, C, or G antigen from S. pyogenes (group A), S. equisimilis (group C), or large-colony group G streptococci. Biochemical tests which were found useful for differentiation included the Voges-Proskauer test, hydrolysis of pyroglutamic acid and beta-D-glucuronide, bacitracin susceptibility, and acid production from ribose. S. milleri represented 56% of the group C, 100% of the group F, and 83% of the nongroupable beta-hemolytic streptococci isolated in our clinical laboratory, whereas the incidence of S. milleri among group A and group G streptococci was estimated to be low. The role of beta-hemolytic S. milleri as a cause of human infection remains obscured by the failure to routinely differentiate S. milleri from other beta-hemolytic streptococci.

Nucleotide sequence of the streptokinase gene from Streptococcus equisimilis H46A

The entire nucleotide sequence of a cloned 2568-bp PstI fragment from the genome of Streptococcus equisimilis H46A encoding the streptokinase gene ( skc) has been determined. The longest open reading frame comprises 1320 bp which code for streptokinase. The protein is synthesized with a 26-amino acid residue N-terminal extension having properties characteristic of a signal peptide. Comparison of the deduced amino acid sequence with the available amino acid sequence of a commercial streptokinase reveals minor primary structure differences. The nucleotide sequencing of skc does not support the hypothesis that the gene has evolved by duplication and fusion, as suggested by internal twofold amino acid homologies of its product. Furthermore, the skc gene sequence shows no extended regions homologous to the staphylokinase gene. Upstream from the skc gene, the putative skc promoter and the ribosome-binding site sequence have been identified; downstream from the coding region, inverted repeat sequences thought to function as transcription terminators have been detected.

Binding of human fibronectin to group A, C, and G streptococci.

A total of 387 bacterial strains belonging to 35 species were tested in direct binding experiments for the uptake of purified radiolabeled human fibronectin. Positive binding was found in group A, C, and G streptococci and in Staphylococcus aureus. The group C streptococcal species Streptococcus equisimilis, Streptococcus zooepidemicus, Streptococcus equi, and Streptococcus dysgalactiae were uniformly reactive with fibronectin. Beta-hemolytic bovine group G streptococci showed the same degree of reactivity as human group G strains. In contrast, only 4 out of 15 alpha-hemolytic bovine group G strains were able to bind fibronectin. The uptake of fibronectin measured at room temperature with a human group G streptococcus was a slow, time-dependent process with maximum binding after approximately 1 h. Human polyclonal immunoglobulin G and serum albumin tested in inhibition experiments did not affect the fibronectin binding. Fibronectin seems, therefore, to interact with a surface component that is different from the specific binding sites previously described for human immunoglobulin G and serum albumin.