Streptococcus oralis Employs Multiple Mechanisms of Salivary Mucin Binding That Differ Between Strains.

Streptococcus oralis is an oral commensal and opportunistic pathogen that can enter the bloodstream and cause bacteremia and infective endocarditis. Here, we investigated the mechanisms of S. oralis binding to oral mucins using clinical isolates, isogenic mutants and glycoconjugates. S. oralis bound to both MUC5B and MUC7, with a higher level of binding to MUC7. Mass spectrometry identified 128 glycans on MUC5B, MUC7 and the salivary agglutinin (SAG). MUC7/SAG contained a higher relative abundance of Lewis type structures, including Lewis b/y, sialyl-Lewis a/x and α2,3-linked sialic acid, compared to MUC5B. S. oralis subsp. oralis binding to MUC5B and MUC7/SAG was inhibited by Lewis b and Lacto-N-tetraose glycoconjugates. In addition, S. oralis binding to MUC7/SAG was inhibited by sialyl Lewis x. Binding was not inhibited by Lacto-N-fucopentaose, H type 2 and Lewis x conjugates. These data suggest that three distinct carbohydrate binding specificities are involved in S. oralis subsp. oralis binding to oral mucins and that the mechanisms of binding MUC5B and MUC7 differ. Efficient binding of S. oralis subsp. oralis to MUC5B and MUC7 required the gene encoding sortase A, suggesting that the adhesin(s) are LPXTG-containing surface protein(s). Further investigation demonstrated that one of these adhesins is the sialic acid binding protein AsaA.

Prospective Surveillance of Pediatric Invasive Group A Streptococcus Infection.

BACKGROUND: Invasive group A Streptococcus (GAS) disease has an incidence in high-income countries of 3 to 5 per 100000 per annum and a case-fatality ratio of 10% to 15%. Although these rates are comparable to those of invasive meningococcal disease in Australia before vaccine introduction, invasive GAS disease currently requires reporting in only 2 jurisdictions. METHODS: Data were collected prospectively through active surveillance at the Royal Children's Hospital, Melbourne (October 2014 to September 2016). Isolation of GAS from a sterile site was required for inclusion. Comprehensive demographic and clinical data were collected, and emm typing was performed on all isolates. Disease was considered severe if the patient required inotropic support or mechanical ventilation. RESULTS: We recruited 28 patients. The median age of the patients was 3.5 years (range, 4 days to 11 years). Ten (36%) patients had severe disease. Fifteen (54%) children had presented to a medical practitioner for review in the 48 hours before their eventual admission, including 7 of the 10 patients with severe GAS infection. Complications 6 months after discharge persisted in 21% of the patients. emm1 was the most common emm type (29%). CONCLUSION: We found considerable short- and longer-term morbidity associated with pediatric invasive GAS disease in our study. Disease manifestations were frequently severe, and more than one-third of the patients required cardiorespiratory support. More than one-half of the patients attended a medical practitioner for assessment but were discharged in the 48-hour period before admission, which suggests that there might have been a window for earlier diagnosis. Our methodology was easy to implement as a surveillance system.

Neuroanatomical features and its usefulness in classification of patients with PANDAS.

OBJECTIVE: An obsessive-compulsive disorder (OCD) subtype has been associated with streptococcal infections and is called pediatric autoimmune neuropsychiatric disorders associated with streptococci (PANDAS). The neuroanatomical characterization of subjects with this disorder is crucial for the better understanding of its pathophysiology; also, evaluation of these features as classifiers between patients and controls is relevant to determine potential biomarkers and useful in clinical diagnosis. This was the first multivariate pattern analysis (MVPA) study on an early-onset OCD subtype. METHODS: Fourteen pediatric patients with PANDAS were paired with 14 healthy subjects and were scanned to obtain structural magnetic resonance images (MRI). We identified neuroanatomical differences between subjects with PANDAS and healthy controls using voxel-based morphometry, diffusion tensor imaging (DTI), and surface analysis. We investigated the usefulness of these neuroanatomical differences to classify patients with PANDAS using MVPA. RESULTS: The pattern for the gray and white matter was significantly different between subjects with PANDAS and controls. Alterations emerged in the cortex, subcortex, and cerebellum. There were no significant group differences in DTI measures (fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity) or cortical features (thickness, sulci, volume, curvature, and gyrification). The overall accuracy of 75% was achieved using the gray matter features to classify patients with PANDAS and healthy controls. CONCLUSION: The results of this integrative study allow a better understanding of the neural substrates in this OCD subtype, suggesting that the anatomical gray matter characteristics could have an immune origin that might be helpful in patient classification.

[Streptococcal toxic shock syndrome caused by Streptococcus pyogenes: a retrospective study of 15 pediatric cases].

Objective: To improve the understanding of clinical characteristics of streptococcal toxic shock syndrome (STSS) caused by Streptococcus pyogenes (S. pyogenes) in children. Methods: A retrospective study was conducted to analyze the clinical data of STSS caused by S. pyogenes (culture-confirmed) in 7 tertiary hospitals during 2010-2017 in China. Clinical and laboratory data were collected by reviewing the medical records. Results: Fifteen cases of STSS, including 9 males, were confirmed and the ages of the patients ranged from 6 months to 15 years, with median age of 3 years. All cases had the positive blood culture for S. pyogenes and only 3 cases had short course of ß-lactam treatment before blood culture. Medical evaluation was initiated within (5.1±4.6) days after symptom onset. All patients had fever, and 13 patients had multiple organ dysfunction and 10 patients had disseminated intravascular coagulationl (DIC). Twelve cases had severe pneumonia with or without skin and (or) soft tissue infections. Underlying conditions included giant hemangioma of the skin in 2 patients and varicella in 1 patient. All isolated strains in 14 cases were sensitive to penicillin G, ceftriaxone/cefotaxime, vancomycin, but 12 and 13 isolates were resistant to clindamycin and erythromycin, respectively. Eight patients died, and 5 of them died within 24 hours after admission. One patient was lost to follow-up after intended discharge against medical advice. Conclusion: STSS caused by S. pyogenes in children is a severe syndrome with rapid clinical progression and high mortality rate, and thus the pediatricians should be aware of STSS and immediately initiate aggressive treatment for the suspected cases.

Caracterización molecular de cepas invasivas de Streptococcus dysgalactiae subsp. equisimilis: estudio multicéntrico Argentina 2011-2012 / Molecular characterization of invasive Streptococcus dysgalactiae subsp. equisimilis. Multicenter study: Argentina 2011-2012

Streptococcus dysgalactiae subsp. equisimilis (SDSE) has virulence factors similar to those of Streptococcus pyogenes. Therefore, it causes pharyngitis and severe infections indistinguishable from those caused by the classic pathogen. The objectives of this study were: to know the prevalence of SDSE invasive infections in Argentina, to study the genetic diversity, to determine the presence of virulence genes, to study antibiotic susceptibility and to detect antibiotic resistance genes. Conventional methods of identification were used. Antibiotic susceptibility was determined by the disk diffusion and the agar dilution methods and the E-test. Twenty eight centers from 16 Argentinean cities participated in the study. Twenty three isolates (16 group G and 7 group C) were obtained between July 1 2011 and June 30 2012. Two adult patients died (8.7%). Most of the isolates were recovered from blood (60.9%). All isolates carried speJ and ssa genes. stG62647, stG653 and stG840 were the most frequent emm types. Nineteen different PFGE patterns were detected. All isolates were susceptible to penicillin and levofloxacin, 6 (26.1%) showed resistance or reduced susceptibility to erythromycin --#91;1 mef(A), 3 erm(TR), 1 mef(A) + erm(TR) and 1 erm(TR) + erm(B)--#93; and 7 (30.4%) were resistant or exhibited reduced susceptibility to tetracycline --#91;2 tet(M), 5 tet(M) + tet(O)--#93;. The prevalence in Argentina was of at least 23 invasive infections by SDSE. A wide genetic diversity was observed. All isolates carried speJ and ssa genes. Similarly to other studies, macrolide resistance (26.1%) was mainly associated to the MLS B phenotype.

Streptococcus dysgalactiae subsp. equisimilis (SDSE) posee factores de virulencia similares a Streptococcus pyogenes y, en consecuencia, produce faringitis e infecciones graves indistinguibles de las generadas por este patógeno clásico. Los objetivos del estudio fueron conocer la prevalencia de SDSE en infecciones invasivas en Argentina, estudiar su diversidad genética, determinar la presencia de genes de virulencia, ensayar su sensibilidad a los antibióticos y conocer los genes de resistencia. Se emplearon métodos convencionales de identificación. La sensibilidad se determinó por difusión, Etest y dilución en agar. Participaron 28 centros de 16 ciudades argentinas. Se obtuvieron 23 aislamientos (16 del grupo G y 7 del grupo C) desde el 1-7-2011 hasta el 30-6-2012. Se registraron 2 muertes en adultos (8,7%). La mayoría de los aislamientos fueron obtenidos de sangre (60,9%). Todos eran portadores de los genes speJ y ssa. Los genotipos más frecuentes fueron stG62647, stG653 y stG840. Se detectaron 19 pulsotipos distintos. Todos los aislamientos fueron sensibles a penicilina y levofloxacina, 6 (26,1%) presentaron resistencia o sensibilidad disminuida a eritromicina (1 mef--#91;A--#93;, 3 erm--#91;TR--#93;, 1 mef--#91;A--#93; + erm--#91;TR--#93; y 1 erm--#91;TR--#93; + erm--#91;B--#93;) y 7 (30,4%) fueron resistentes o tuvieron sensibilidad disminuida a tetraciclina (2 tet--#91;M--#93;, 5 tet--#91;M--#93; + tet--#91;O--#93;). La prevalencia anual en la Argentina fue de al menos 23 infecciones invasivas por SDSE y se observó una amplia diversidad genética. Todos los aislamientos presentaron los genes ssa y speJ. Como en otros estudios, la resistencia a macrólidos (26,1%) estuvo asociada, principalmente, al fenotipo MLS B.

[MICROBIOLOGICAL ASPECTS OF INFECTIOUS BALANOPOSTHITIS].

Treatment and prevention of diseases of the male reproductive organs largely influence male population fertility and the health of the future generations. This review summarizes current views on the problem of infectious balanoposthitis and presents generalized information on its pathogens. Refined classification and diagnostic workup are provided. The important role of pathogenic microflora in the formation of the glans penis and foreskin inflammation is shown. Importance of Enterococcus spp. in the etiology of balanoposthitis is demonstrated. The modern treatment regimens and prevention of balanoposthitis are described.

Cloning and expression of serum opacity factor in fish pathogenic Streptococcus dysgalactiae and its application to discriminate between fish and mammalian isolates.

Lancefield group C Streptococcus dysgalactiae (GCSD) is known as a causative agent of bovine mastitis and cardiopulmonary diseases in humans. Recently, GCSD has been isolated from diseased fish in Japan. Almost all culture supernatants and sodium dodecyl sulfate extracts obtained from GCSD isolated from farmed fish possessed serum opacity activity. Serum opacity factor (SOF) is a bifunctional cell-associated protein that causes serum opacification. In this study, a gene coding SOF, which was named sof-FD, was identified from GCSD isolated from fish. The amino acid sequence of sof-FD showed 40.1-46.5% identity to those of other SOFs from mammalian strains of S. dysgalactiae and Streptococcus pyogenes. Repetitive fibronectin binding domains were also observed in sof-FD, the structures of which were similar to those of other SOFs, as previously reported. The amino acid sequence of SOF was identical among fish isolates. A primer set targeting the sof-FD gene was designed and applied to a PCR assay for discriminating fish isolates from mammalian isolates.

Relationship between clinical manifestations and pulsed-field gel profiles of Streptococcus canis isolates from dogs and cats.

Little is known regarding the degree of genotypic relatedness between Streptococcus canis isolates from dogs and cats. The purpose of this study was to determine whether correlations existed between the genotypes of canine and feline S. canis isolates as determined using pulsed-field gel electrophoresis (PFGE) and different clinical manifestations of disease. Eighty-two isolates of S. canis were examined that had been collected from dogs and cats presenting to the University of California, Davis Veterinary Medical Teaching Hospital (VMTH) between 1998 and 2005. Associated clinical manifestations included sepsis, otitis, pyometra, skin infections, necrotizing fasciitis, respiratory disease, and urinary tract infections. In addition, 9 feline isolates from a southern California shelter that experienced an outbreak of S. canis infection manifesting as necrotizing fasciitis and death were examined. Bacterial isolates were characterized by PFGE analysis using the restriction enzyme SmaI. The relationships between banding patterns were analyzed using gel analysis software combined with visual interpretation. The feline shelter isolates of S. canis were 99% similar in bacterial PFGE profile. The remainder of samples had less than 80% similarity in PFGE banding patterns. The relatedness of the PFGE profile in the feline shelter isolates suggested a clonal origin. In the isolates from the VMTH population, there was no relationship between specific disease manifestations and PFGE profile. PFGE typing does not appear to be useful for identifying isolates associated with specific disease presentations; however may be more useful to identify outbreaks of S. canis infections or to detect clonal populations in outbreaks.

Streptococcus pyogenes emm and T types within a decade, 1996-2005: implications for epidemiology and future vaccines.

Streptococcus pyogenes group A (GAS) is a primary human pathogen. We performed genetic emm sequence and serological T-antigen typing of 819 mostly invasive GAS isolates recovered in Israel during 1996-2005. Of the 72 emm types found, the six most prevalent types (1, 81, 89, 14, 28, 5) comprised 30.2% of all isolates, and emm-type changes were observed over the years. The predicted coverage of the 26-valent S. pyogenes vaccine formulated for usage in the USA was predicted to be only approximately 60%. On the basis of different emm-T antigen type associations, some Israeli strains are probably different clonal types than those found in USA. About 2% of GAS had emm types that were originally associated with S. dysgalactiae subsp. equisimilis emm genes. Therefore, routine emm typing allows meaningful GAS strain surveillance, and provides data relevant to better vaccine coverage.

Population biology of the human restricted pathogen, Streptococcus pyogenes.

Streptococcus pyogenes, also referred to as beta-hemolytic group A streptococci, are strictly human pathogens with a global distribution and high prevalence of infection. The organisms are characterized by high levels of genetic recombination, extensive strain diversity, and a narrow habitat. This review highlights many key features of the population genetics and molecular epidemiology of this biologically diverse bacterial species, with special emphasis on ecological subdivisions and tissue-specific infections, strain diversity and population dynamics in communities, selection pressures arising from the specific host immune response and antibiotic exposure, and within-host selection during the course of invasive disease.

Randomized, comparative efficacy trial of oral penicillin versus cefuroxime for perianal streptococcal dermatitis in children.

OBJECTIVE: To investigate the efficacy of penicillin compared with cefuroxime for group A beta-hemolytic Streptococcus pyogenes (GABHS) perianal dermatitis. STUDY DESIGN: Children 1 to 16 years of age with signs and symptoms of perianal dermatitis and a positive anal swab were randomized to penicillin or cefuroxime treatment and were clinically re-evaluated on day 3 and at the end of treatment (cefuroxime, day 7; penicillin, day 10). An anal swab was obtained to document eradication of GABHS at the end of treatment. Severity of disease was assessed with a clinical score (perianal erythema, 5 points; perianal itch, 3 points; painful defecation, 3 points; constipation, 2 points). RESULTS: Patients were enrolled and randomly assigned to penicillin (n = 18) or cefuroxime (n = 17) treatment. Treatment with penicillin was inferior to cefuroxime, which led to premature study termination after consultation with the ethics committee. Clinical improvement was more rapid in the cefuroxime group (P = .028) and GAHBS was not isolated from the anus the last day of therapy in 13 of 14 patients treated with cefuroxime compared with 7 of 15 patients treated with penicillin (P < .01). CONCLUSIONS: Cefuroxime was more effective than penicillin and therefore should be considered as the treatment of choice for perianal dermatitis due to GABHS.

Human case of Streptococcus suis serotype 16 infection.

Streptococcus suis infection is an emerging zoonosis in Southeast Asia. We report a fatal case of S. suis serotype 16 infection in a Vietnamese man in 2001.

[Invasive Streptococcus agalactiae infections in non-pregnant adults]. / Les infections invasives à Streptococcus agalactiae chez l'adulte (femme enceinte exclue).

OBJECTIVES: Streptococcus agalactiae (Group B streptococcus) is a major cause of invasive diseases in non-pregnant adults, particularly in the elderly and those with underlying conditions. We describe these conditions and clinical characteristics of patients followed in our teaching hospital. METHODS: We retrospectively reviewed clinical records of 64 patients with S. agalactiae-related invasive infection, hospitalized between January 1997 and January 2006. RESULTS: The mean age of patients was 59 (+/-17 years). The H:F sex ratio was 1.06. At least one underlying condition was found in 90.6%. Diabetes mellitus (43.7%), peripheral vascular disease (34.4%), myocardial ischemia (20.3%) and malignant neoplasms (20.3%) were among the most frequent conditions. The mean index of comorbidity (Charlson) was 2.5 (+/-2). Common clinical manifestations included infection of the urinary tract (32.8%), skin and soft-tissue (25%), and osteoarthritis (21.9%). Bacteremia occurred in 31.2% with no identified source in 2 patients. During the first month, 2 cases of endocarditis, 1 case of meningitis, and 4 deaths occurred. CONCLUSION: We confirm the importance of underlying diseases in the emergence of S. agalactiae infections.

Febre reumática / Rheumatic fever

A febre reumática (FR) é seqüela da infecção de orofaringe pelo estreptococo beta-hemolítico do grupo A, em 3 a 4% das crianças (3 a 18 anos) acometidas por faringoamidalite, e não tratadas, que apresentam fatores genéticos predispondo ao desenvolvimento da doença. A doença reumática cardíaca (DRC) é considerada...

Endocardite infecciosa em valva nativa / Infective endocarditis at native valve

A endocardite é uma das doenças de mais rica propedêutica na cardiologia. Desde a primeira descrição de um quadro clínico sugestivo de endocardite infecciosa, em 1646, por Lazare Reviere, muitas mudanças ocorreram, com progressiva sistematização de diagnóstico e terapêutica. Após mais de 200 anos...

Investigation of the effect of the coronal restoration quality on the composition of the root canal microflora in teeth with apical periodontitis by means of T-RFLP analysis.

AIM: To investigate the effect of the radiographic and clinical quality of coronal restorations on the composition of the root canal flora of teeth with necrotic pulps and teeth with root fillings associated with apical periodontitis. METHODOLOGY: Twenty-eight necrotic pulps and 35 root filled canals with signs of apical periodontitis were studied. Both the coronal filling (presence of radiographically or clinically deficient margins and/or secondary caries) and the root filling (homogeneity and length) were scored. Bacterial root canal samples were taken with sterile paper points under rubber dam and using measures to prevent contamination. A DNA-based nonculture bacterial identification technique was used, namely terminal restriction fragment length polymorphism (T-RFLP) analysis. RESULTS: Twelve samples were negative for bacterial DNA. A total of 33 different terminal restriction fragments (TRFs) were detected. The Fusobacterium nucleatum/Streptococcus mitis group was the most frequently encountered TRF. The mean number of TRFs per necrotic pulp was 6.2 and 5.8 for the groups with acceptable and unacceptable coronal restorations, respectively. This difference was not significant. In the root filled group, these values (respectively, 5.2 and 8.6) were statistically significantly different (P < 0.05). The following parameters in root filled teeth had no significant influence on the mean numbers of TRFs detected: the length and homogeneity of the root filling and the type of tooth (anterior-premolar-molar). CONCLUSION: T-RFLP allowed the rapid assessment of bacterial biodiversity in root canal samples. The technique revealed the presence of bacteria that have rarely been described in the root canals of teeth with apical periodontitis. Biodiversity in the root filled group was high, as compared with culture-dependent studies where monoinfections were more frequently reported. Only in root filled teeth did defective coronal restorations have a statistically significant influence on the mean numbers of detected TRFs per sample.