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PubMed1983

Antipolysaccharide group-specific antibodies of Streptococcus pyogenes in children.

Evaluation of a new microtest for the detection of Streptococcus pyogenes group A antipolysaccharide antibodies in 996 control children and 562 streptococcal infections from 0 to 12 years. The case-list was divided in 4 groups, years 0-2. 2-4. 4-8. 8-12 for the evaluation of the age-related normality range. Under 2 years normal values between 60 and 120 U, from 2 to 12 years normal values under 240 U. In streptococcal infections identical patterns for the pathological values in the 4 age-ranges considered, with positivity percentage from 85% to 95%, thus confirming the same antibody response also in breast-fed children, unlike what occurs for ASO under 2 years, when the response is present only in 25% of the cases and in the 2-4 years age-range in 33.3%. Evident diagnostic superiority of MSK as compared with ASO in adenitis, pyodermic infections, bronchopneumopathies, acute tonsillitis at the onset of symptomatology. In rheumatic disease the percentage of positivity for MSK and ASO is similar, in post-streptococcal glomerulonephritis and in Schoenlein-Henoch syndrome the percentage of positivity for MSK is higher than for ASO. It is suggested the utility of insertion of MSK test in the routine assay for streptococcal infections diagnosis above all in children under 4 years and in infections with low or slow antigenic charge for 0-streptolysin.

Child↗

PubMed1976

Susceptibility of Staphylococcus aureus, Streptococcus pyogenes and Diplococcus pneumoniae to antibiotics. Comparison of patterns in Poland and Federal Republic of Germany.

One hundred and eighty five strains of Gram-positive cocci were tested for susceptibility to 16 antibiotics, including some newer drugs, by agar dilution technique. Of these, 100 strains (50 each isolated in Poland and Germany) were Staphylococcus aureus, 55 Streptococcus pyogenes, and 30 Diplococcus pneumoniae. Previous investigations of streptococci and pneumococci isolated in Poland and Federal Republic of Grmany, revealed no differences in antibiotic-susceptibility patterns in both countries, which was not the case with staphylococci. Present study demonstrates further evidence for existence of differences in antibiotic-sensitivity of staphylococci, depending of their geographical origin, and presents actual state of susceptibility to antibiotics of Streptococcus pyogenes and Diplococcus pneumoniae.

Anti-Bacterial Agents↗

PubMed2003

Comparative activity of garenoxacin and other agents by susceptibility and time-kill testing against Staphylococcus aureus, Streptococcus pyogenes and respiratory pathogens.

OBJECTIVES: Garenoxacin is a novel des-F(6)quinolone that has shown excellent antimicrobial activity against a wide range of clinically important microorganisms. In this study, its activity was examined, in comparison with that of other antimicrobial agents, by susceptibility and time-kill testing against Staphylococcus aureus, Streptococcus pyogenes and respiratory pathogens. METHODS: Overall, 200 bacterial strains were tested. The antimicrobial activity of garenoxacin was compared with that of ciprofloxacin, levofloxacin, moxifloxacin, amoxicillin, co-amoxiclav, cefuroxime, cefotaxime, ceftriaxone, imipenem, erythromycin and clarithromycin. In addition, the bactericidal activity of garenoxacin, moxifloxacin, levofloxacin and ciprofloxacin was evaluated by time-kill analysis against four strains each of staphylococci [two methicillin-susceptible (MSSA) and two methicillin-resistant (MRSA)], pneumococci (two penicillin-susceptible and two penicillin-resistant) and Streptococcus pyogenes (two erythromycin-susceptible and two erythromycin-resistant). Antibiotics were tested at concentrations 1-8 x MIC. RESULTS: MIC90 values of garenoxacin for the MSSA and MRSA strains were 0.03 and 2 mg/L, respectively. Among all the quinolones tested, garenoxacin yielded the lowest MIC values against all pneumococci (MIC90 0.12 mg/L) irrespective of macrolide resistance; the rank order of activity was garenoxacin> moxifloxacin>levofloxacin>ciprofloxacin. Excellent activity was shown also against Haemophilus influenzae (MIC90 or= 3 log10 decrease in viable counts (cfu/mL) within 3 h at 4 x MIC, whereas a moderate, slower killing rate was observed versus streptococci. CONCLUSIONS: This investigational des-F(6)quinolone represents a promising alternative for the treatment of respiratory tract infections.

Anti-Infective Agents↗

PubMed1984

An outbreak of Streptococcus pyogenes infections in a nursing home.

An outbreak of serious infections caused by Streptococcus pyogenes occurred in a nursing home for elderly patients. The outbreak began in mid-winter and continued for 12 months. Thirteen residents and two nurses had infections. Severity of infection was worse in residents, who developed sepsis, necrotizing fasciitis, cellulitis, septic arthritis, pneumonia, and conjunctivitis; in contrast, the nurses had pharyngitis only. Six of thirteen residents required acute hospital care, and the index case died with sepsis. Typing of S. pyogenes was done in 13 of 15 cases, and the same serotype (M-non-typable, T-25) was found. Control measures consisted of identifying all patients with infections, obtaining cultures, and providing prompt treatment. Patients in nursing homes are highly susceptible to serious infections with S. pyogenes.

Aged↗

PubMed1996

Phylogenetic distribution of streptococcal superantigen SSA allelic variants provides evidence for horizontal transfer of ssa within Streptococcus pyogenes.

Phylogenetic analyses recently found the gene encoding the streptococcal superantigen SSA of Streptococcus pyogenes to occur in several well-differentiated clones comprising 10 (12.5%) of 80 clonal lineages examined. To determine if distinct clonal lineages carried the same ssa coding sequence or harbored a group of allelic variants, ssa was sequenced from 23 S. pyogenes strains representing the 10 clones identified by multilocus enzyme electrophoresis. Three alleles of ssa were found in natural populations of S. pyogenes. ssa-1 and ssa-3 differed by a single synonymous substitution in codon 94; both encoded SSA-1. Each of these alleles was present in phylogenetically diverse clones that had not shared a recent common ancestor. ssa-2 was present in a single clonal lineage. It was identical to ssa-3 at codon 94 but had a nonsynonymous substitution at codon 28 that changed the second amino acid of the mature protein from serine to arginine. This substitution altered the predicted isoelectric point and affected the apparent molecular mass during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Despite sequence variation both upstream of and within the ssa locus, all ssa-positive lineages expressed either SSA-1 or SSA-2. The observed patterns of ssa allele-clone distribution provide evidence for individual incidences of horizontal transfer and recombination of ssa among distinct group A streptococcal lineages. Although the extensive homology of SSA to the staphylococcal superantigen SEB raises the possibility of intergeneric gene transfer, a search for ssa in 68 genetically diverse clones of Staphylococcus aureus did not identify the gene. Moreover, the absence of ssa among 119 representative strains of Lancefield group B, C, or G streptococci suggests that ssa is confined to S. pyogenes.

Alleles↗

PubMed2003

Bacitracin-resistant clone of Streptococcus pyogenes isolated from pharyngitis patients in Belgium.

We report 16 bacitracin-resistant Streptococcus pyogenes isolates recovered from pharyngitis patients in Belgium, 14 of which belonged to a particular emm type (emm28). All 16 isolates were constitutively resistant to macrolides and carried erm(B). The emergence of a bacitracin-resistant S. pyogenes clone raises questions about the continued reliability of bacitracin susceptibility testing for S. pyogenes identification.

Anti-Bacterial Agents↗

PubMed1992

Streptococcus pyogenes outbreak in a long-term care facility.

BACKGROUND: Although outbreaks involving Streptococcus pyogenes have been uncommon among the elderly population, recent reports suggest that this organism is an important nosocomial pathogen among institutionalized older patients and carries significant morbidity and mortality. An outbreak of S. pyogenes, type M12, T12, occurred in a large long-term care institution serving the ill and chronically disabled. The outbreak involved 14 residents of the intermediate care facility and lasted for 4 months. METHODS: A prospective epidemiologic investigation was initiated at the onset of the outbreak. Pertinent clinical and demographic information regarding both residents and personnel was obtained by interview, review of medical and surveillance records, and examination of patients for lesions. Cultures were obtained within 24 hours of symptom onset from those with characteristic clinical symptoms. Unpaired convalescent sera were tested for group A streptococcal extracellular antigens by a rapid hemagglutination slide test. Control measures included active surveillance of residents and staff for suspicious clinical syndromes, transfer of high-risk patients, elimination of a common seating area, and improved handwashing and hygiene measures. RESULTS: The attack rate was 7.5%, with 64.3% of these patients residing on one unit. S. pyogenes was isolated from eight residents, 5 residents had a characteristic syndrome and an elevated streptozyme hemagglutination titer of 400, and 1 resident died within hours of having cellulitis of the groin. Clinical syndromes included cellulitis, pharyngitis, bronchitis, pneumonia, and septicemia. Seven residents required acute care; two residents died within 3 weeks of the onset, yielding a case fatality rate of 14.3%. CONCLUSIONS: The major means of transmission appeared to be direct contact between residents, although transmission from an infected staff member may have accounted for some cases. The hypothesis of long-term colonization was supported by the extended times between infections. The severity of illness and the apparent transmission through direct contact between residents warrants (1) early detection of infected lesions, (2) recognition of invasive illness, (3) prompt effective treatment, and (4) surveillance for S. pyogenes infections among residents and personnel.

Aged↗

PubMed2003

Survival of Streptococcus pyogenes within host phagocytic cells: a pathogenic mechanism for persistence and systemic invasion.

Streptococcus pyogenes is generally an extracellular pathogen that can survive and persist within the host by circumventing the host defense mechanisms. To achieve this, S. pyogenes has developed a number of strategies to circumvent the host immune system (e.g., virulence factors directed to prevent phagocytosis). By use of a murine model of skin infection, it was shown that survival within host phagocytic cells constitutes an additional strategy used by S. pyogenes to evade the host defenses and disseminate. Viable microorganisms were isolated from mouse phagocytic cells after in vitro or during in vivo infection. The capacity of intracellularly located bacteria to establish infection was demonstrated by the efficiency of gentamicin-treated neutrophils isolated from infected mice to transfer infection when injected intravenously into naive mice. The ability of S. pyogenes to exploit the inflammatory response of the host by surviving inside phagocytic cells may constitute an additional virulence mechanism of this pathogen.

Animals↗

PubMed2005

Telithromycin activity is reduced by efflux in Streptococcus pyogenes.

OBJECTIVES: To investigate whether telithromycin is a substrate for efflux pumps in Streptococcus pyogenes. METHODS: The distribution of telithromycin MICs was analysed for two distinct collections of Italian (n=486) and Spanish (n=210) S. pyogenes strains. The effect of an efflux mechanism was investigated using [(3)H]telithromycin. RESULTS: Telithromycin MIC ranges were < or = 0.004-0.06 mg/L (MIC(50) and MIC(90), 0.01 mg/L) in erythromycin-susceptible strains (lacking both mef and erm genes) and 0.01-1 mg/L (MIC(50) and MIC(90), 0.5 mg/L) in strains endowed with the M phenotype and expressing the mef(A) gene. A distinct telithromycin efflux was detected in the strains expressing the mef(A) gene, but not in those expressing the erm(B) gene, nor in the susceptible strains lacking mef(A) or erm genes. Efflux reversibility by addition of an inhibiting compound (sodium arsenate) was demonstrated. An msr-like sequence was also found in all strains effluxing telithromycin, but not in the others. CONCLUSIONS: This study shows that telithromycin can be removed from S. pyogenes by efflux. That the efflux is related to the presence of the mef(A) gene is demonstrated, but-owing to the increasingly evident complexity of S. pyogenes efflux systems-the possibility that other genes may contribute to the efflux cannot be excluded.

Anti-Bacterial Agents↗

PubMed2003

Identification and characterization of a Streptococcus pyogenes operon involved in binding of hemoproteins and acquisition of iron.

The hemolytic Streptococcus pyogenes can use a variety of heme compounds as an iron source. In this study, we investigate hemoprotein utilization by S. pyogenes. We demonstrate that surface proteins contribute to the binding of hemoproteins to S. pyogenes. We identify an ABC transporter from the iron complex family named sia for streptococcal iron acquisition, which consists of a lipoprotein (siaA), membrane permease (siaB), and ATPase (siaC). The sia transporter is part of a highly conserved, iron regulated, 10-gene operon. SiaA, which was localized to the cell membrane, could specifically bind hemoglobin. The operon's first gene encodes a novel bacterial protein that bound hemoglobin, myoglobin, heme-albumin, and hemoglobin-haptoglobin (but not apo-haptoglobin) and therefore was named Shr, for streptococcal hemoprotein receptor. PhoZ fusion and Western blot analysis showed that Shr has a leader peptide and is found in both membrane-bound and soluble forms. An M1 SF370 strain with a polar mutation in shr was more resistant to streptonigrin and hydrogen peroxide, suggesting decreased iron uptake. The addition of hemoglobin to the culture medium increased cell resistance to hydrogen peroxide in SF370 but not in the mutant, implying the sia operon may be involved in hemoglobin-dependent resistance to oxidative stress. The shr mutant demonstrated reduced hemoglobin binding, though cell growth in iron-depleted medium supplemented with hemoglobin, whole blood, or ferric citrate was not affected, suggesting additional systems are involved in hemoglobin utilization. SiaA and Shr are the first hemoprotein receptors identified in S. pyogenes; their possible role in iron capture is discussed.

ATP-Binding Cassette Transporters↗

PubMed1985

Human plasma fibronectin inhibits adherence of Streptococcus pyogenes to hexadecane.

The effect of human plasma fibronectin on the adherence of Streptococcus pyogenes to hexadecane droplets was investigated. Fibronectin blocked the adherence of streptococci to hexadecane in a dose-dependent manner. The inhibitory effect resulted from the binding of fibronectin to the streptococcal cells; radiolabeled fibronectin failed to bind to the hexadecane but bound readily to untreated streptococci. Chemical treatments of streptococci that decreased streptococcal binding of fibronectin also decreased their binding to hexadecane. Pretreatment of fibronectin with lipoteichoic acid blocked the binding of fibronectin to streptococci and abolished its ability to inhibit streptococcal adherence to hexadecane in a dose-related manner. In contrast, wheat germ agglutinin, which binds to N-acetylglucosamine on the surface of S. pyogenes cells, failed to alter hexadecane adherence. The data suggest that fibronectin binds to lipoteichoic acid on the surface of the streptococci, thereby preventing lipoteichoic acid from interacting with the hexadecane phase.

Alkanes↗

PubMed1995

Isolation and characterization of a novel collagen-binding protein from Streptococcus pyogenes strain 6414.

In this report we have analyzed the binding of collagen to Streptococcus pyogenes strain 6414. This binding was rapid, specific, and involved a limited number of receptor molecules (11,600 copies per cell). When the proteins in a streptococcal lysate were blotted onto a nitrocellulose filter and probed with 125I-labeled collagen, a prominent collagen-binding protein of 57 kDa was identified as well as minor 130-150-kDa components. The major 57-kDa protein was isolated by affinity chromatography on collagen-Sepharose followed by gel filtration chromatography. The 57-kDa protein purified from S. pyogenes was used to raise a monospecific antibody which also reacted with a collagen-binding protein of similar molecular size isolated from Streptococcus zooepidemicus. The two collagen-binding proteins from streptococci have a similar amino acid composition and isoelectric points. Isolated collagen-binding protein was specifically recognized by 125I-collagen in a solid-phase binding assay and displayed an affinity for the ligand quite similar to that exhibited by intact bacteria (Kd = 3.1 versus 3.5 x 10(-9) M, respectively). Surface-labeled bacteria attached to microtiter wells coated with different collagen types and the 57-kDa protein blocked the adhesion to collagen substrate. We propose that the 57-kDa protein is an adhesin involved in the attachment of streptococci to host tissues.

Amino Acid Sequence↗

PubMed2002

Erythromycin resistance in italian isolates of Streptococcus pyogenes and correlations with pulsed-field gel electrophoresis analysis.

Erythromycin resistance among Streptococcus pyogenes strains has been reported in Italy at high rates during the last few years. A total of 152 erythromycin-resistant isolates of this species from southern Italian regions were characterized for the macrolide-resistance phenotype and screened by PCR for the corresponding genetic determinant. A close correlation was found between these phenotypic/genotypic data concerning macrolide resistance and results of Sma I macrorestriction fragment patterns (PFGE) analysis. In fact, the vast majority of the isolates assigned to individual PFGE classes mostly belonged to a single phenotype of macrolide resistance. All untypeable isolates belonged to the M phenotype. Twenty-two distinct PFGE types were recognized, of which 11 were recorded in only one isolate (one-strain type); about 50% of typeable isolates fell into five type clusters and 70% in seven. The increased erythromycin resistance among Italian isolates of S. pyogenes does not appear to be due to the spread of a single clone, but results indicate that the majority of group A streptococci examined are probably spread from a limited number of clones.

Anti-Bacterial Agents↗

PubMed1977

[Relationships between Streptococcus pyogenes T4-antigens and haptoglobin types (author's transl)].

Some strains of beta-haemolytic streptococci were agglutinated with high titers (1:200-1:6400) by human sera of the haptoglobin types 2-2 and 2-1. No agglutination or with low titers (up to 1:20) was observed with sera of the haptoglobin type 1-1. This reactivity depends from the contents of Streptococcus pyogenes T-antigens of the T-complex 4,24... This T4-antigen is present in group A streptococci (Strep. pyogenes) of the types 4, 24, 26, 28, 29, 46, 48 and 60 but it may be present also in some strains of streptococcal groups C and G. During a 10-year period we isolated 12 strains of Strep. equisimilis (group C) carrying the T-4 antigen (1.6%) and 50 group-G streptococci with T-4 antigen (6.4%) of all group G streptococci). These strains were agglutinated without an exception with high titers by Hp 2-2 and Hp 2-1 sera but not by sera of the haptoglobin type 1-1. The same particuliarity was shown by Streptococcus pyogenes types of the T-complex 4, 24... One strain of type 26 (BC 179) has no T antigen and therefore it was not agglutinated in the above mentioned manner. The phenomenon depends from the medium; it occurs after cultivation of the streptococci in Pope broth or in meat-infusion with glucose but not or only reduced in beef heart-proteose-medium. The agglutination reaction is caused by the haptoglobin but not by agglutinins against the T4-antigens.

Agglutination↗

PubMed2005

Intranasal immunization with serum opacity factor (SOF) of Streptococcus pyogenes fails to protect mice against lethal mucosal challenge with a heterologous strain.

Streptococcus pyogenes is a human pathogen causing invasive and non-invasive diseases, as well as severe sequels, such as rheumatic fever. Several bacterial factors have been proposed as candidate vaccine antigens. Among them, the serum opacity factor (SOF), which was able to confer protective immunity against an intraperitoneal challenge after vaccination by the parenteral route. In an attempt to develop more efficient vaccines, we combined SOF with an additional well-known protective antigen, namely, the fibronectin-binding protein I (SfbI). Intranasal immunization of mice with SOF and SfbI stimulates strong systemic and mucosal immune responses against both antigens. Animals vaccinated with SfbI, alone or in combination with SOF, were also efficiently protected against a lethal challenge with a SOF/SfbI-positive virulent S. pyogenes strain (80% survival). In contrast, those vaccinated with SOF alone were not protected against a mucosal challenge (100% lethality), which mimics more closely natural infections. These results highlight the importance of developing adequate experimental animal models to evaluate vaccine efficiency, according to the selected antigen.

Adhesins, Bacterial↗

PubMed1982

Minimum amount of penicillin prophylaxis required to control Streptococcus pyogenes epidemic in closed community.

The prophylaxis required to control an epidemic of Streptococcus pyogenes throat infection in a junior detention centre has been reported. In a further epidemic an attempt was made to determine the minimum amount of penicillin required to control the outbreak. Oral penicillin (0.5 g) given as a single daily dose for 10 days to all boys after entry proved effective. The added risk of relatively deprived adolescent boys developing rheumatic fever is stressed.

Adolescent↗

PubMed2005

Macrolide- and telithromycin-resistant Streptococcus pyogenes, Belgium, 1999-2003.

We found a 13% macrolide resistance in 3,866 Streptococcus pyogenes isolated from tonsillopharyngitis patients; 59% macrolide-resistant isolates were distributed in 5 clones, suggesting the importance of both resistance gene transfer and clonal dissemination in the spread of these organisms. We also report one of the largest collections of telithromycin-resistant isolates.

Adolescent↗

PubMed2003

Rheumatic fever-associated Streptococcus pyogenes isolates aggregate collagen.

Acute rheumatic fever is a serious autoimmune sequel of Streptococcus pyogenes infection. This study shows that serotype M3 and M18 S. pyogenes isolated during outbreaks of rheumatic fever have the unique capability to bind and aggregate human basement membrane collagen type IV. M3 protein is identified as collagen-binding factor of M3 streptococci, whereas M18 isolates bind collagen through a hyaluronic acid capsule, revealing a novel function for M3 protein and capsule. Following in vivo mouse passage, conversion of a nonencapsulated and collagen-binding negative M1 S. pyogenes into an encapsulated, collagen-binding strain further supports the crucial role of capsule in mediating collagen binding. Collagen binding represents a novel colonization mechanism, as it is demonstrated that S. pyogenes bind to collagen matrix in vitro and in vivo. Moreover, immunization of mice with purified recombinant M3 protein led to the generation of anti-collagen type IV antibodies. Finally, sera from acute rheumatic fever patients had significantly increased titers of anti-collagen type IV antibodies as compared with healthy controls. These findings may suggest a link between the potential of rheumatogenic S. pyogenes isolates to bind collagen, and the presence of collagen-reactive autoantibodies in the serum of rheumatic fever patients, which may form a basis for post-streptococcal rheumatic disease. These anti-collagen antibodies may form a basis for poststreptococcal rheumatic disease.

Animals↗