Abscesos cerebrales múltiples por Streptococcus milleri / Multiple brain abscesses due to Streptococcus milleri

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[Multiple brain abscesses due to Streptococcus milleri]. / Abscesos cerebrales múltiples por Streptococcus milleri.

TITLE: Abscesos cerebrales múltiples por Streptococcus milleri.

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)

Estreptococos del grupo Streptococcus anginosus Parte IIIb. Infecciones en localizaciones diferentes de las de cabeza y cuello / Streptococcus anginosus group. Part IIIb. Other than head and neck infections

Resumen Las bacterias del grupo Streptococcus anginosus (EGA) son colonizantes habituales de las mucosas orofaríngea, intestinal y genitourinaria, pero, cada vez más frecuentemente, son reconocidas como patógenos humanos. En esta parte III se describen las tendencias de los EGA a la producción de distintas patologías humanas. Por su extensión debió ser desdoblada a su vez en otras dos partes (IIIa y IIIb). 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, huesos, articulaciones, etc. Se han encontrado asociados con infecciones urinarias, vaginitis aeróbica y 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 infecciosas, generalmente complicadas con abscesos perivalvulares. Esta parte IIIb está focalizada en las infecciones que no comprometen la cabeza y el cuello.

Abstract Streptococcus anginosus (SGA) group streptococci are common colonizers of the oropharyngeal, intestinal, and genitourinary mucosa, but they are increasingly recognized as human pathogens. In this part III, tendencies of the EGA to the production of different human pathologies are described. Due to its length, it had to be divided into two other parts (IIIa and IIIb). Its ability to form abscesses in solid organs, especially brain, lung and liver abscesses, is widely known. They also cause sinusitis, empyema and collections in skin and soft tissues, bones, joints, etc. They have been found associated with urinary tract infections, aerobic vaginitis and with pulmonary exacerbations in patients with cystic fibrosis and chronic obstructive pulmonary disease. They also cause infections after human bites, disseminated infections, bacteremia without apparent focus and, to a lesser extent, infective endocarditis, generally complicated by perivalvular abscesses. This part IIIb is focused on other than head and neck infections.

Resumo As bactérias do grupo Streptococcus anginosus (EGA) são colonizadores comuns da mucosa orofaríngea, intestinal e geniturinária, mas são cada vez mais reconhecidos como patógenos humanos. Nesta parte III são descritas as tendências do EGA à produção de diferentes patologias humanas. Devido ao seu comprimento, teve que ser dividido em duas outras partes (IIIa e IIIb). Sua capacidade de formar abcessos em órgãos sólidos, principalmente cérebro, pulmão e fígado, é amplamente conhecida. Eles também causam sinusite, empiema e coleções na pele e tecidos moles, ossos, articulações, etc. Eles foram encontrados associados à infecções urinárias, vaginite aeróbia e às exacerbações pulmonares em pacientes com fibrose cística e doença pulmonar obstrutiva crônica. Também causam infecções após picadas humanas, infecções disseminadas, bacteremia sem origem aparente e, em menor grau, endocardite infecciosa, geralmente complicada por abscessos perivalvulares. Seu papel na faringite é controverso, embora algumas das subespécies possam estar envolvidas em tais infecções. Seu potencial carcinogênico também é postulado pela associação com carcinomas orofaríngeos, gástricos ou esofágicos. Esta parte IIIb enfoca infecções em diferentes locais da cabeça e pescoço.

Images of the month: Cavernous sinus venous thrombosis secondary to Streptococcus milleri maxillary sinusitis: An unusual cause of diplopia and headache.

Cavernous sinus venous thrombosis is an uncommon condition associated with high mortality rates if not recognised early. Symptoms include headache, visual loss, ophthalmoplegia, altered consciousness, proptosis and periorbital oedema. High-quality imaging is critical in early diagnosis and successful management. Primary infection (such as sinusitis) and possible complications (including meningitis) should be considered as potential aetiologies of cavernous sinus venous thrombosis, especially in those with a preceding history of localised infection. We present a case of a 50-year-old man with a bilateral cavernous sinus venous thrombosis with associated meningitis caused by Streptococcus milleri, secondary to maxillary sinusitis and otomastoiditis. He was successfully treated with antimicrobial treatment, surgical drainage and anticoagulation.

Lemierre's syndrome involving milleri group streptococci: further insight into age and aetiology.

Lemierre's syndrome (LS) is a suppurative thrombophlebitis of the internal jugular vein secondary to otorhinolaryngologic infection. It is classically associated with the Gram-negative anaerobe Fusobacterium necrophorum (FN) and is thought to be a disease of young people. Here, we describe the case of a 56-year-old woman with LS involving milleri group streptococci (MGS), which has been reported only 13 times since it was first observed in 2003. Subgroup analysis of all published cases of LS involving MGS demonstrated these patients were significantly older than those involving FN (median age 49 years versus 18 years, p = 0.007, IQR 36-58 years), although this finding is limited by publication bias. This report clarifies a 2014 hypothesis regarding the relationship between age and aetiology in this rare disease. While FN remains the most common cause of LS overall, empiric antibiotic therapy should also cover oral streptococci such as MGS, even in younger adults.

Paradoxical High-Level Spiramycin Resistance and Erythromycin Susceptibility due to 23S rRNA Mutation in Streptococcus constellatus.

Objectives: The aim of the study was to characterize phenotypically and genotypically an uncommon mechanism of resistance to macrolides, lincosamides, and streptogramins (MLS) in a Streptococcus milleri group clinical isolate. Materials and Methods: The isolate UCN96 was recovered from an osteoradionecrosis wound, and was identified using the matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and the partial sequencing of the sodA gene. Antimicrobial susceptibility testing were carried out by the disk diffusion method and minimal inhibitory concentrations (MICs) were determined by the broth microdilution technique. PCR screening was performed for MLS resistance genes described in Gram-positive bacteria. Specific mutations in the ribosomal proteins L3-, L4-, and L22-encoding genes were also screened and those in domain V of the 23S rRNA gene (rrl). The number of mutated copies of the rrl gene was determined using amplification-refractory mutation system quantitative-polymerase chain reaction (qPCR) analysis. Results: The clinical isolate UCN96 was unambiguously identified as Streptococcus constellatus. It was susceptible to all macrolides and lincosamides (ML) antibiotics except spiramycin (MIC >256 mg/L) while it was also resistant to streptogramins. Screening for all acquired resistance genes was negative and no mutation was found in genes coding for L3, L4, and L22 ribosomal proteins. Of interest, a single mutation, A2062C (according to Escherichia coli numbering), was detected in the domain V of 23S rRNA. Conclusion: Mutations at the position 2062 of 23S rRNA have been detected once in Streptococcus pneumoniae, and not yet in other Streptococcus spp. This mechanism is very likely uncommon in Gram-positive bacteria because different copies of 23S rRNA operons should be mutated for development of such a resistance pattern.

A pediatric case of central skull base osteomyelitis caused by Streptococcus milleri group infection and mimicking malignancy.

Central skull base osteomyelitis (CSBO) that has expanded to the middle cranial fossa is a rare complication of nasopharyngeal infection in children. Diagnosing CSBO is challenging in children, because specific symptoms are lacking and imaging findings can mimic skull base malignancy. We report on a 3-year-old girl who complained of pyrexia, headache, and vomiting and in whom a mass around the clivus was detected with magnetic resonance imaging. The patient received a diagnosis of CSBO based on characteristic imaging findings and the detection of a Streptococcus milleri group (SMG) in blood cultures. Clinical symptoms and abnormal imaging findings, including a mass lesion, were improved by prompt antibiotic treatment. The present patient had paranasal sinusitis with bacteremia of SMG, leading to the speculation of hematogeneous dissemination of SMG from the paranasal sinus. Awareness of CSBO, its early diagnosis, and aggressive management are required because CSBO is associated with high morbidity due to a life-threating infection involving multiple cranial nerves.

Prevalence and antibiotic susceptibility of group A beta-haemolytic streptococcal isolates in children presenting with acute pharyngitis in Lusaka, Zambia

Background. Group A beta-haemolytic streptococci (GABHS)-associated pharyngitis can complicate into rheumatic fever and rheumatic heart disease (RHD).Objectives. To determine the prevalence and antibiotic susceptibility of GABHS isolates in children presenting with acute pharyngitis and assess the utility of Zambian Treatment Guideline (ZTG) criteria as a local clinical scoring system.Methods. This descriptive cross-sectional study was conducted at the paediatric outpatient department of the University Teaching Hospital in Lusaka, Zambia. The study cohort, comprising children aged 3 - 15 years (n=146), were recruited as presenting with symptoms of pharyngitis. The children underwent a clinical assessment that included a detailed case history, presenting symptoms and a throat swab that was subsequently cultured. Microbial isolates were typed and the antibiotic sensitivity of cultured GABHS to penicillin and erythromycin determined.Results. GABHS were cultured from 22 (15.1%) children within this study. All the GABHS isolates (n=22) were susceptible to penicillin G; however, 19% of isolates displayed reduced susceptibility to erythromycin. None of the ZTG criteria, when used individually, was sufficiently sensitive to detect GABHS pharyngitis among this cohort.Conclusion. The prevalence of GABHS pharyngitis is similar that been described elsewhere. While GABHS remains highly susceptible to penicillin, which is used in the local RHD control programmes, concern remains for children treated with erythromycin owing to the resistance noted in some of the isolates. The ZTG clinical criteria displayed poor sensitivity in identifying GABHS pharyngitis. This has significant implications for effective diagnosis and treatment of pharyngitis and associated complications within this high RHD endemic area

Polymicrobial Cerebral Abscess in a Child with Uncorrected Tetralogy of Fallot.

Aggregatibacter aphrophilus and Beta haemolytic Streptococci Lancefield group F are part of the normal oral flora and are known to cause endocarditis, sinusitis, empyema, meningitis and septic arthritis. They are now emerging as a cause of brain abscess particularly in patients with congenital heart diseases. We report a case of a 10-year-old boy with Tetralogy of Fallot (TOF), who presented with fever, headache and drowsiness. Culture yielded the growth of Aggregatibacter aphrophilus and Beta hemolytic streptococci Lancefield group F. He became clinically stable after treatment with ceftriaxone.

Clinical characteristics and treatment outcomes in a cohort of patients with pyogenic and amoebic liver abscess.

BACKGROUND: We describe the clinical features of a cohort of patients with liver abscesses and investigate relationships between clinical, radiological and microbiological findings and mortality. METHODS: Retrospective review of pyogenic (PLA) or amoebic liver abscesses (ALA) diagnosed and treated at a major infectious diseases department in London over 9 years. RESULTS: One hundred forty-one patient records were identified; 132 (93.6%) had PLA and 9 (6.4%) ALA. No organism was identified in 38.6% (51/132); a single bacterial species was isolated in 47.0% (62/132) of PLA, ≥ 2 in 14.4% (19/132). There was weak evidence of variation in abscess size by type of microorganism, with streptococcal PLA typically larger (p = 0.03 for Streptococcus milleri group, p = 0.05 for non-milleri streptococci). Patients with ALA were younger (median 41, IQR 37-51 years) than those with PLA (median 68, IQR 50.5-78 years) (p = 0.003) and all were male (9/9, 100%, (p = 0.03)), with a history of recent travel in the majority (6/9, 66.7% (p = 0.003)). C-reactive protein was higher in ALA than in PLA (p = 0.06). In the entire cohort, loculation (HR = 2.51 (95% CI 1.00-6.32), p = 0.04) and baseline ALP (HR = 4.78 (95% CI 1.19-19.2) per log10 increase, p = 0.03) were associated with mortality. 16S ribosomal RNA (rRNA) analysis was used in a subset of culture-negative cases and increased the diagnostic yield by 13%. CONCLUSIONS: Clinical or radiological features cannot be used to distinguish between PLA and ALA, or help identify the bacterial cause of PLA. However, ALA is more common in young, male patients with a history of travel. 16S rRNA analysis of abscess fluid has a role in improving microbiological diagnosis in culture-negative cases.

Successive complications after anterior cervical fixation: pharyngoesophageal diverticulum, fistulization, and cervical spondylitis by Streptococcus milleri - case report and literature review.

INTRODUCTION: Pharyngoesophageal diverticulum is an uncommon complication after anterior cervical discectomy and fusion surgery. CASE PRESENTATION: Our patient was a 48-year-old woman with two previous cervical surgeries with fixation of C4-C5 and C5-C6, the last one in 2003. Two years after surgery, she presented with arthralgia, arthritis, chills, and fluctuating rash. In 2007, she presented with dysphagia, halitosis, and sputum production. She was diagnosed with a pharyngoesophageal diverticulum with a fistula to C6 vertebra and secondary spondylitis. She was taken for open surgery with removal of screws and plates, cricopharyngeal myotomy, and esophageal repair. Streptococcus milleri grew in tissue and osteosynthetic material. She received 4 months of amoxicillin and probenecid and had a complete recovery. Since 1991, 19 similar cases have been reported with one fatality. To our knowledge, this is the first reported case of diverticulum complicated with fistula and secondary spondylitis. CONCLUSIONS: In patients with a history of anterior cervical discectomy and fusion complaining of dysphagia, even years after surgery, it is mandatory to perform an esophagogram. This symptom was referred to in 88% of the cases reported in the literature.

The Yin and Yang of Streptococcus Lung Infections in Cystic Fibrosis: a Model for Studying Polymicrobial Interactions.

The streptococci are increasingly recognized as a core component of the cystic fibrosis (CF) lung microbiome, yet the role that they play in CF lung disease is unclear. The presence of the Streptococcus milleri group (SMG; also known as the anginosus group streptococci [AGS]) correlates with exacerbation when these microbes are the predominant species in the lung. In contrast, microbiome studies have indicated that an increased relative abundance of streptococci in the lung, including members of the oral microflora, correlates with impacts on lung disease less severe than those caused by other CF-associated microflora, indicating a complex role for this genus in the context of CF. Recent findings suggest that streptococci in the CF lung microenvironment may influence the growth and/or virulence of other CF pathogens, as evidenced by increased virulence factor production by Pseudomonas aeruginosa when grown in coculture with oral streptococci. Conversely, the presence of P. aeruginosa can enhance the growth of streptococci, including members of the SMG, a phenomenon that could be exacerbated by the fact that streptococci are not susceptible to some of the frontline antibiotics used to treat P. aeruginosa infections. Collectively, these studies indicate the necessity for further investigation into the role of streptococci in the CF airway to determine how these microbes, alone or via interactions with other CF-associated pathogens, might influence CF lung disease, for better or for worse. We also propose that the interactions of streptococci with other CF pathogens is an ideal model to study clinically relevant microbial interactions.

Pseudomonas aeruginosa Can Inhibit Growth of Streptococcal Species via Siderophore Production.

Cystic fibrosis (CF) is a genetic disease that causes patients to accumulate thick, dehydrated mucus in the lung and develop chronic, polymicrobial infections due to reduced mucociliary clearance. These chronic polymicrobial infections and subsequent decline in lung function are significant factors in the morbidity and mortality of CF. Pseudomonas aeruginosa and Streptococcus spp. are among the most prevalent organisms in the CF lung; the presence of P. aeruginosa correlates with lung function decline, and the Streptococcus milleri group (SMG), a subgroup of the viridans streptococci, is associated with exacerbations in patients with CF. Here we characterized the interspecies interactions that occur between these two genera. We demonstrated that multiple P. aeruginosa laboratory strains and clinical CF isolates promote the growth of multiple SMG strains and oral streptococci in an in vitro coculture system. We investigated the mechanism by which P. aeruginosa enhances growth of streptococci by screening for mutants of P. aeruginosa PA14 that are unable to enhance Streptococcus growth, and we identified the P. aeruginosapqsL::TnM mutant, which failed to promote growth of Streptococcus constellatus and S. sanguinis Characterization of the P. aeruginosa ΔpqsL mutant revealed that this strain cannot promote Streptococcus growth. Our genetic data and growth studies support a model whereby the P. aeruginosa ΔpqsL mutant overproduces siderophores and thus likely outcompetes Streptococcus sanguinis for limited iron. We propose a model whereby competition for iron represents one important means of interaction between P. aeruginosa and Streptococcus spp.IMPORTANCE Cystic fibrosis (CF) lung infections are increasingly recognized for their polymicrobial nature. These polymicrobial infections may alter the biology of the organisms involved in CF-related infections, leading to changes in growth, virulence, and/or antibiotic tolerance, and could thereby affect patient health and response to treatment. In this study, we demonstrate interactions between P. aeruginosa and streptococci using a coculture model and show that one interaction between these microbes is likely competition for iron. Thus, these data indicate that one CF pathogen may influence the growth of another, and they add to our limited knowledge of polymicrobial interactions in the CF airway.

Is FCH PET able to identify foci of infection superiorly to FDG PET?

We report a case of a brain abscess identified on fluorine-18 choline (FCH) positron emission tomography (PET) scan, which was not identified on fluorodeoxyglucose (FDG) PET scan. To our knowledge, there are no previous case reports of incidental brain abscess identified by FCH PET imaging. A 51-year-old man, with liver cirrhosis complicated by hepatocellular carcinoma (HCC) was enrolled in a research trial comparing HCC detection in FCH PET versus FDG PET. During the course of the trial, he underwent radiofrequency ablation (RFA) for HCC. A repeat FCH PET scan post-RFA incidentally revealed a 2.5 cm lesion with avid uptake in the left occipital area of the brain. The patient was asymptomatic. MRI suggested this was an abscess. A craniotomy and drainage was performed, with culture of Streptococcus intermedius (Smilleri group) from the thick-walled collection, a causative organism for previous episode of pneumonia. He successfully completed a 6 week course of antibiotics.

In vitro/in vivo evaluation of the efficacy of gatifloxacine-loaded PLGA and hydroxyapatite composite for treating osteomyelitis.

Molten 10 wt% gatifloxacine (GLFX-loaded poly(lactide-co-glycolide) (PLGA) was introduced into three-dimensionally interconnected pores and onto the surfaces of hydroxyapatite (HA) granules. The composite granules exhibited clinically sufficient bactericidal activities against Streptococcus milleri and Bacteroides fragilis from 3 h to 10 days. The composite granules were implanted in bone defects created by debridement of osteomyelitis lesions in rabbit mandibles. After 4-week implantation, inflammation in the composite granule-implanted group was significantly smaller than that in the debridement group (p<0.05). Moreover, newly formed bone was observed in the pores and on the surface of HA granules of the composite. These findings show that GFLX/HA composite controls bacterial infection and supports bone regeneration for osteomyelitis treatment.

Idiopathic pretracheal deep neck space infection with mediastinal extension: A series of 3 cases and review of the literature.

Idiopathic pretracheal deep neck space infection is an extremely rare condition with potentially devastating complications. We present a series of 3 cases of pretracheal deep neck space infection that arose in the absence of trauma or a congenital lesion and that exhibited mediastinal spread. To the best of our knowledge, these cases represent the first reported series of this rare condition to be published in the English-language literature. All cultures grew Streptococcus milleri, and all patients had a favorable outcome. A high index of suspicion for a deep neck space infection is warranted in view of the devastating complications of this condition. Computed tomography is the investigation of choice. Treatment with intravenous antibiotics and surgical drainage, particularly when mediastinitis is present, is recommended. This rare presentation warrants a thorough investigation to identify the source of infection.

[Streptococcus milleri: An unusual cause of skull extensive osteomyelitis in an immunocompetent patient]. / Streptococcus milleri : une cause inhabituelle d'ostéite extensive du crâne chez un patient immunocompétent.

INTRODUCTION: Streptococcus milleri (Streptococcus anginosus, intermedius and constellatus) are commensal organisms, which can become pathogenic and cause infection with frequent abscess formation, local or metastatic extension. Osteomyelitis of the skull has been rarely reported in this type of infection. CASE REPORT: Skull osteomyelitis due to Streptococcus milleri is reported in a 61-year-old immunocompetent man without any medical history, occurring 10 months after a head injury without any wound or complication at initial presentation. A progressive right parieto-occipital headache with worsening and increased acute phase reactants evoked a giant cell arteritis. After few days of corticosteroid therapy (0.5 mg/kg/day), diagnosis of subcutaneous abscess associated to an extensive osteomyelitis of the skull due to Streptococcus milleri was diagnosed. The outcome was favorable after drainage of one liter of pus, irrigation, debridement and antibiotherapy by amoxicillin for 8 weeks. CONCLUSION: It is necessary to discuss the differential diagnosis of giant cell arteritis particularly when symptoms are unusual. Even a short-term corticosteroid therapy may dramatically exacerbate an undetected infection.

Late aortic silver graft re-infection due to Streptococcus milleri group (Streptococcus anginosus). Case report and literature review / Reinfección tardía de prótesis aórtica de plata debida a grupo Streptococcus milleri (Streptococcus anginosus). Reporte de caso y revisión de la literatura

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