Infecciones por estreptococos del grupo S. anginosus en pediatría / S. anginosus group streptococcal infections in children

Los estreptococos del grupo Streptococcus anginosus (EGA), también llamados "Streptococcus milleri", fueron reconocidos como parte de los estreptococos del grupo viridans (EGV) desde principios del siglo XX. Su rol como patógenos humanos, sin embargo comenzó a destacarse recién en la década de 1970. En esta actualización se describen aspectos microbiológicos y clínicos de los EGA. Los métodos fenotípicos de identificacón e incluso algunos genotípicos carecen de precisión para reconocer las tres especies del grupo (Streptococcus anginosus, Streptococcus constellatus y Streptococcus intermedius) e incluso pueden fallar en su clasificación a nivel de grupo. La mayoría de ellos son sensibles a los antibióticos beta-lactámicos pero son considerables los porcentajes de resistencia a macrólidos, lincosamidas y tetraciclinas. Los EGA son colonizantes habituales de las mucosas orofaríngea, intestinal y genitourinaria, pero, cada vez más frecuentemente, son reconocidos como patógenos humanos. Es ampliamente conocida su capacidad de formar abscesos en órganos sólidos, especialmente abscesos cerebrales, pulmonares y hepáticos. También producen sinusitis, empiemas y colecciones en piel y tejidos blandos, hueso, articulaciones, etc. Se han encontrado asociados con exacerbaciones pulmonares en pacientes con fibrosis quística y con enfermedad pulmonar obstructiva crónica. Producen también infecciones posteriores a mordeduras humanas, infecciones diseminadas, bacteriemia sin foco aparente y, en menor medida, endocarditis infecciosa (AU)

Streptococci from the Streptococcus anginosus group (SAG), also termed "Streptococcus milleri", were recognized as members of the viridans group streptococci (VGS) in the early 20th century. Nevertheless, their role as human pathogens only became evident in the 1970s. In this update, microbiological and clinical aspects of the SAG are described. Phenotypic and even some genotypic identification methods lack accuracy in recognizing the three species of the group (Streptococcus anginosus, Streptococcus constellatus, and Streptococcus intermedius) and may fail to classify them at the group level. Most of them are sensitive to beta-lactam antibiotics but rates of resistance to macrolides, lincosamides, and tetracyclines are significant. SAGs are common colonizers of the oropharyngeal, intestinal, and genitourinary mucosa, but are increasingly recognized as human pathogens. Their ability to form abscesses in solid organs, especially brain, lung and liver, is widely known. They may produce sinusitis, empyemas, and collections in skin and soft tissues, bone, joints, etc. They have also been associated with pulmonary exacerbations in patients with cystic fibrosis and chronic obstructive pulmonary disease. In addition, they may cause infections following human bites, disseminated infections, bacteremia without apparent focus, and, to a lesser extent, infective endocarditis (AU)

Angicin, a novel bacteriocin of Streptococcus anginosus.

As a conserved defense mechanism, many bacteria produce antimicrobial peptides, called bacteriocins, which provide a colonization advantage in a multispecies environment. Here the first bacteriocin of Streptococcus anginosus, designated Angicin, is described. S. anginosus is commonly described as a commensal, however it also possesses a high pathogenic potential. Therefore, understanding factors contributing to its host colonization and persistence are important. A radial diffusion assay was used to identify S. anginosus BSU 1211 as a potent bacteriocin producer. By genetic mutagenesis the background of bacteriocin production and the bacteriocin gene itself were identified. Synthetic Angicin shows high activity against closely related streptococci, listeria and vancomycin resistant enterococci. It has a fast mechanism of action and causes a membrane disruption in target cells. Angicin, present in cell free supernatant, is insensitive to changes in temperature from - 70 to 90 °C and pH values from 2 to 10, suggesting that it represents an interesting compound for potential applications in food preservation or clinical settings.

Late onset periprosthetic joint infection of the knee caused by Streptococcus anginosus. Case presentation and literature review.

Periprosthetic joint infection (PJI) is one of the most dramatic complications of joint arthroplasty. Although streptococcal bone and joint infections are less common than staphylococcal cases, their role as causative agents of bone and joint remains significant accounting for at least 10% of PJIs. Streptococcus anginosus group (SAG) bacteria are usually found in the normal flora of the urogenital tract, intestinal tract and oropharynx and could cause pyogenic infections to affect brain, lungs and liver. SAG bacteria are uncommonly reported as a cause of osteomyelitis and the involvement of a joint represent a rare event. S. anginosus has been anecdotical related to implant devices infections such as vascular prosthesis or orthopedic implants, however, PJI of the knee has never been fully reported before. We describe the case of a late onset periprosthetic knee infection due to Streptococcus anginosus successfully treated by a two-stage revision arthroplasty and postoperative parenteral Vancomycin, (2 g per day) and Levofloxacin (750 mg per day) for 4 weeks and then oral Levofloxacin for a further 2 weeks.

Changes in the Vaginal Microbiome during the Pregnancy to Postpartum Transition.

Substantial changes in the composition of the vaginal microbiome occur following the end of pregnancy. To identify potential drivers of microbiome changes in individual women during the pregnancy to postpartum transition, we evaluated vaginal samples from 48 pregnant women during their first and third trimesters and postpartum. We determined the species composition of vaginal communities and the vaginal fluid levels of compounds involved in mediating changes in host physiology and the immune system at each time point. We used linear mixed-effects models to characterize associations. Consistent with previous reports, but with a larger sample size, a US population, and variations in the dominant bacteria, the vaginal microbiome was found to be more diverse during the postpartum period. There was a lower abundance of Lactobacillus and significantly higher proportions of Streptococcus anginosus and Prevotella bivia. Moreover, we uniquely demonstrated that postpartum vaginal secretions were also altered postpartum. There were elevated levels of hyaluronan and Hsp70 and decreased levels of the D- and L-lactic acid isomers. We posit that these variations are consequences of alterations in the vagina after delivery that profoundly alter the host environment and, thus, lead to changes in the capability of different bacterial species to survive and proliferate.

Prosthetic valve endocarditis caused by silent infection of methicillin-resistant coagulase-negative staphylococci.

Surgery for prosthetic valve endocarditis in the mitral valve position is still challenging for surgeons. Reconstruction of the mitral annulus is useful for patients with a mitral annulus disputed by infection. Here, we report a redo mitral valve replacement using a collar-reinforced tissue valve, which was inserted into a mitral annulus reconstructed with a bovine patch. Though the preoperative blood culture detected Streptococcus anginosus, the intraoperative culture detected methicillin-resistant coagulase-negative staphylococci (MRCNS). MRCNS is rarely detected because of its indolent nature.

Update on the in vitro activity of dalbavancin against indicated species (Staphylococcus aureus, Enterococcus faecalis, ß-hemolytic streptococci, and Streptococcus anginosus group) collected from United States hospitals in 2017-2019.

This study updates dalbavancin activity against contemporary (2017-2019) isolates of indicated species/groups (n = 16,451). Isolates from 71 hospitals were tested by broth microdilution method. All isolates were susceptible to dalbavancin. Dalbavancin MIC50/90 values remained stable for Staphylococcus aureus, vancomycin-susceptible Enterococcus faecalis, ß-hemolytic streptococci, and Streptococcus anginosus group since its clinical approval.

Oral infectious bacteria in dental plaque and saliva as risk factors in patients with esophageal cancer.

BACKGROUND: High levels of periodontopathic bacteria as well as Streptococcus anginosus were detected in cancer tissue from patients with esophageal cancer. An association between oral infectious bacteria and esophageal cancer has been reported. METHODS: Characteristics of the oral microbiota and periodontal conditions were studied as clinicopathologic factors in patients with esophageal cancer. The study included 61 patients with esophageal cancer and 62 matched individuals without any cancers. Samples of subgingival dental plaque and unstimulated saliva were collected to evaluate the prevalence and abundance of the following oral bacteria using a real-time polymerase chain reaction assay: Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Treponema denticola, and S. anginosus. RESULTS: In the cancer group, the prevalence of all bacteria, with the exception of F. nucleatum, in dental plaque; the prevalence of A. actinomycetemcomitans in saliva; the abundance of all bacteria, with the exception of F. nucleatum and P. intermedia, in dental plaque; and the abundance of A. actinomycetemcomitans and S. anginosus in saliva were significantly higher. Furthermore, a logistic regression analysis suggested that the prevalence of T. forsythia and S. anginosus in dental plaque and of A. actinomycetemcomitans in saliva, as well as a drinking habit, were associated with a high risk of esophageal cancer, with a high odds ratio. CONCLUSIONS: The current findings have potential implications for the early diagnosis of esophageal cancer.

Asymptomatic man with an incidental finding of a massive empyema.

We describe the case of a 67-year-old asymptomatic man who was referred to our hospital for abnormal laboratory results. He was incidentally found to have a massive empyema without underlying bronchopulmonary pneumonia. Following thoracentesis, he was diagnosed with chronic Streptococcus anginosus empyema. Therapeutic thoracentesis and treatment with tissue plasminogen activator and deoxyribonuclease failed to resolve the empyema, and there was residual loculated pleural fluid that was surrounded by a thick rind. The patient was referred to thoracic surgery for decortication of the pleural space via video-assisted thoracoscopic surgery. At 2-month follow-up, the patient had complete re-expansion of the lung tissue.

Tyrosine tRNA synthetase as a novel extracellular immunomodulatory protein in Streptococcus anginosus.

Streptococcus anginosus is frequently detected in patients with infective endocarditis, abscesses or oral cancer. Although S. anginosus is considered the causative pathogen of these diseases, the pathogenic mechanisms of the bacterium have remained unclear. Previously, we suggested that an extracellular antigen from S. anginosus (SAA) serves as a pathogenic factor by inducing nitric oxide production in murine macrophages. In the present study, we identified SAA using LC-MS/MS and assessed the biological activities of His-tagged recombinant SAA in murine macrophages. SAA was identified as a tyrosine tRNA synthetase (SaTyrRS) that was isolated from the extracellular fraction of S. anginosus but not from other oral streptococci. In addition, inducible nitric oxide synthase and TNF-α mRNA expression was induced in recombinant SaTyrRS-stimulated murine macrophages. However, their mRNA expression was not induced in macrophages stimulated with truncated or heat-inactivated recombinant SaTyrRS, and the activation motif was identified as Arg264-Thr270. Consequently, these results indicated that SaTyrRS could be a novel and specific immunomodulatory protein in S. anginosus.

Transbronchial Needle Aspiration Cytology and Purulent Pericarditis.

Endobronchial ultrasound with transbronchial needle aspiration (TBNA) is commonly performed for the evaluation of mediastinal lymphadenopathy. Purulent pericarditis is a rare, yet potentially fatal complication of TBNA. It commonly presents with nonspecific symptoms such as chest pain, shortness of breath, palpitations, or vague abdominal discomfort. Additionally, more severe symptoms such as cardiac tamponade and even death have been reported. In this article, we present the case of a 58-year-old male who developed purulent pericardial effusion with tamponade thought to be caused by TBNA cytology. This case raises an important question regarding the current guidelines for prophylactic antibiotic treatment for patients at high risk of developing purulent pericarditis as a complication of TBNA.

Rapidly progressive necrotizing pneumonia: remember the Streptococcus anginosus group!

Acute necrotizing pneumonia in an immunocompetent host is uncommon and usually caused by Staphylococcus aureus infection. Streptococcus anginosus group (SAG) is a less recognized cause of rapidly destructive lung infection resulting in significant patient morbidity and mortality. Unlike many other bacterial infections, SAG can cross fascial planes and cause fulminant infections. Necrotizing pneumonia and lung abscesses due to SAG often fails conservative therapy with antimicrobials and requires definitive surgical intervention. Consideration of SAG as a potential etiology might help to institute definitive therapy earlier and prevent complications.

Lung abscess secondary to lung cancer with Eikenella corrodens and Streptococcus anginosus: a case report.

BACKGROUND: Eikenella corrodens and Streptococcus anginosus, which are primary colonization bacteria of the normal flora of the oropharynx, are infrequent bacteria, especially the former. Here, we report a case of lung abscess with a coinfection of Eikenella corrodens and Streptococcus anginosus in a lung cancer patient. CASE PRESENTATION: A 66-year-old Chinese man with lung cancer was admitted to the hospital, complaining of a cough and expectoration for five months and fever for two months. After a series of inspections to differentiate a cancer-related fever from an infectious fever, he was diagnosed with lung abscess. Draining pus culture demonstrated Eikenella corrodens and Streptococcus anginosus. After more than 1 month of antibiotic therapy and draining in total, he gradually recovered to fight against lung cancer. CONCLUSION: This report highlights the increased pathogenicity of Eikenella corrodens and Streptococcus anginosus in an immunocompromised cancer patient, especially after a few invasive operations. Additionally, even though a patient has been diagnosed with cancerous fever, strong vigilance is needed in case an infection arises.

Bladder bacterial diversity differs in continent and incontinent women: a cross-sectional study.

BACKGROUND: Since the discovery of the bladder microbiome (urobiome), interest has grown in learning whether urobiome characteristics have a role in clinical phenotyping and provide opportunities for novel therapeutic approaches for women with common forms of urinary incontinence. OBJECTIVE: This study aimed to test the hypothesis that the bladder urobiome differs among women in the control cohort and women affected by urinary incontinence by assessing associations between urinary incontinence status and the cultured urobiome. STUDY DESIGN: With institutional review board oversight, urine specimens from 309 adult women were collected through transurethral catheterization. These women were categorized into 3 cohorts (continent control, stress urinary incontinence [SUI], and urgency urinary incontinence [UUI]) based on their responses to the validated Pelvic Floor Distress Inventory (PFDI) questionnaire. Among 309 women, 150 were in the continent control cohort, 50 were in the SUI cohort, and 109 were in the UUI cohort. Symptom severity was assessed by subscale scoring with the Urinary Distress Inventory (UDI), subscale of the Pelvic Floor Distress Inventory. Microbes were assessed by expanded quantitative urine culture protocol, which detects the most common bladder microbes (bacteria and yeast). Microbes were identified to the species level by matrix-assisted laser desorption and ionization time-of-flight mass spectrometry. Alpha diversity indices were calculated for culture-positive samples and compared across the 3 cohorts. The correlations of UDI scores, alpha diversity indices, and species abundance were estimated. RESULTS: Participants had a mean age of 53 years (range 22-90); most were whites (65%). Women with urinary incontinence were slightly older (control, 47; SUI, 54; UUI, 61). By design, UDI symptom scores differed (control, 8.43 [10.1]; SUI, 97.95 [55.36]; UUI, 93.71 [49.12]; P<.001). Among 309 participants, 216 (70%) had expanded quantitative urine culture-detected bacteria; furthermore, the urinary incontinence cohorts had a higher detection frequency than the control cohort (control, 57%; SUI, 86%; UUI, 81%; P<.001). In addition, the most frequently detected species among the cohorts were as follows: continent control, Lactobacillus iners (12.7%), Streptococcus anginosus (12.7%), L crispatus (10.7%), and L gasseri (10%); SUI, S anginosus (26%), L iners (18%), Staphylococcus epidermidis (18%), and L jensenii (16%); and UUI, S anginosus (30.3%), L gasseri (22%), Aerococcus urinae (18.3%), and Gardnerella vaginalis (17.4%). However, only Actinotignum schaalii (formerly Actinobaculum schaalii), A urinae, A sanguinicola, and Corynebacterium lipophile group were found at significantly higher mean abundances in 1 of the urinary incontinence cohorts when compared with the control cohort (Wilcoxon rank sum test; P<.02), and no individual genus differed significantly between the 2 urinary incontinence cohorts. Both urinary incontinence cohorts had increased alpha diversity similar to continent control cohort with indices of species richness, but not evenness, strongly associated with urinary incontinence. CONCLUSION: In adult women, the composition of the culturable bladder urobiome is associated with urinary incontinence, regardless of common incontinence subtype. Detection of more unique living microbes was associated with worsening incontinence symptom severity. Culturable species richness was significantly greater in the urinary incontinence cohorts than in the continent control cohort.

Co-infection with Streptococcus anginosus and Mycobacterium tuberculosis in an immunocompetent pediatric patient. A case report.

BACKGROUND: Simultaneous infection in tuberculosis (TB) is rare. The mixed infection between Streptococcus anginosus group (SAG) and M. tuberculosis (MTB) has not been reported in children. The aim of this report was to describe a pediatric case with a pulmonary abscess caused by the duality SAG-MTB co-infection. CASE PRESENTATION: An 11-year-old boy with an acute onset of throbbing pain of two-day evolution located in the anterior chest wall. The patient reported a history of fever, cough and rhinorrhea during the last seven days. An anterior chest radiography revealed a heterogenic opacity at the lower right lobe while the lateral projection showed an obliteration at the anterior diaphragmatic insertion. Parenteral Ceftriaxone (100 mg/kg/day) and Dicloxacillin (200 mg/kg/day) was started. The abscess was subsequently drained and analyzed. After a year of follow-up, the patient remained asymptomatic. CONCLUSION: This case represents the first reported case of pulmonary co-infection involving MTB and SAG in an immunocompetent pediatric patient.

Clinical characteristics of patients with bacterial pleuritis in the presence of Streptococcus anginosus group and obligate anaerobes detected by clone library analysis.

INTRODUCTION: Bacterial pleuritis is one of the most important pleural and respiratory infectious diseases, in addition, there have been no reports describing the clinical characteristics of patients with bacterial pleuritis according to molecular methods. An accurate understanding of the clinical characteristics and etiology of bacterial pleuritis is an issue that must be addressed. OBJECTIVES: The aim of this study was to clarify the clinical characteristics of the bacterial species in bacterial pleuritis. METHODS: Pleural effusion samples were obtained from 29 patients with bacterial pleuritis. The microbiota of pleural effusion samples was analyzed by clone library analysis using the 16S ribosomal RNA gene. RESULTS: The phylotypes of Fusobacterium spp. (24.1%) were most frequently the predominant phylotypes, followed by those of Streptococcus anginosus group (SAG) (20.7%) and S. aureus (17.2%). The predominant phylotypes of obligate anaerobes, including the Fusobacterium spp., were detected in 11 of 29 patients (37.9%). Patients in the SAG group were significantly older and presented lower serum albumin levels than those in the obligate anaerobe and other bacterial groups. Patients from the obligate anaerobe group took longer to present symptoms, and therefore the diagnosis of pleuritis was also delayed, in comparison to patients in the other bacterial groups. CONCLUSIONS: Our results demonstrated that there were characteristic differences between patients in SAG, obligate anaerobe and other bacterial groups. Physicians may need to consider treatment strategy options based on the clinical characteristics of patients with bacterial pleuritis.

Invasive pyogenic infection and infective endocarditis due to Streptococcus anginosus: A case report.

RATIONALE: Streptococcus anginosus mostly colonizes the digestive and genitourinary system, including the oropharyngeal region. It commonly causes invasive pyogenic infection, but less likely causes infective endocarditis (IE). PATIENT CONCERNS: An 18-year-old woman who had an underlying mitral valve prolapse without mitral regurgitation presented to our hospital with low-grade fever, left leg weakness, and left abdominal pain. She was diagnosed with brain infarction and microabscess as well as IE. The patient totally recovered after the 6-week course of intravenous antibiotics. DIAGNOSIS: Brain magnetic resonance imaging revealed brain infarction and microabscess. Abdominal computed tomography revealed splenic and left renal infarction. Three sets of blood culture were positive for S anginosus. Transthoracic echocardiogram identified mitral valve prolapse with moderate eccentric mitral valve regurgitation, and a 0.3 × 0.6-cm vegetation was found on the left mitral valve. All of these results meet the modified Duke criteria. INTERVENTIONS: The abdominal pain and left leg weakness were improving after 2 weeks of intravenous antibiotics treatment. No neurological sequelae were noted after completing the 6-week course of medical treatment. OUTCOMES: The patient was successfully treated and discharged after completing the 6-week intravenous antibiotics treatment. LESSONS: IE should be considered in young patients with native valve disease who have prolonged fever. Though S anginosus commonly causes invasive pyogenic infection, patients with native valve disease should be checked for IE.

Treating an intramuscular abscess following toothpick injury in a diabetic patient: A case report and literature review (CARE Complaint).

RATIONALE: Toothpick puncture (TPP) is a penetrating injury that can result in bringing pathogens to the deep space. Such penetrating wounds are typically of pinpoint size with initial symptoms appearing subtle. Consequently, the injury itself is often neglected by patients, or is not detected during physical examinations by medical doctors. Reported complications from such injuries include osteomyelitis and septic arthritis, mostly due to delayed treatment. PATIENT CONCERNS: A diabetic patient aged 83-year-old presented a 2-day history of skin redness, swelling, and tenderness over his forearm following a TPP a week earlier. Laboratory investigations showed leukocytosis with neutrophilic predominance and a high level of C-reactive protein. Before his operation, cultures of aspirated fluid from the injured site revealed the presence of Streptococcus anginosus, Streptococci viridans, Prevotella intermedia, and Pavimonas (Peptostreptococcus) micra. DIAGNOSIS: Intramuscular abscess associated with toothpick injury. INTERVENTIONS: Surgical irrigation with debridement and adjunctive antibiotics of ceftriaxone and clindamycin were given with a satisfactory response. Cultures of debrided tissue showed the presence of P intermedia and P (Peptostreptococcus) micra. OUTCOMES: A split-thickness skin graft was done. Patient was discharged on the 30th postoperative day. LESSONS: Toothpick injury, initial symptoms of which are subtle, can in some cases, lead to serious complications especially when managements are delayed. In such situations (including the present case), surgical irrigation and debridement are administrated for the eradication of infections, removal of potentially retained toothpick, and tissue cultures analyzed. Adjunctive antibiotics is recommended to combat both the aerobic and anaerobic microorganisms of the gastrointestinal tract, skin surface, and oral cavity.

A Rare Case of Myonecrosis with Soft-Tissue Emphysema in a Diabetic Foot Caused by Streptococcus anginosus Isolated in Pure Culture: A Case Study.

Streptococcus anginosus (SAG) is a known human pathogen and member of the Streptococcus milleri group. SAG is a known bacterial cause of soft-tissue abscesses and bacteremia and is an increasingly prevalent pathogen in infections in patients with cystic fibrosis. We describe a rare case of SAG as an infectious agent in a case of nonclostridial myonecrosis with soft-tissue emphysema. This is the only case found in the literature of SAG cultured as a pure isolate in this type of infection and was associated with a prolonged course of treatment in an otherwise healthy patient.