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.

Is there any difference in pyogenic liver abscess caused by Streptococcus milleri and Klebsiella spp?: retrospective analysis over a 10-year period in a regional hospital.

BACKGROUND/PURPOSE: To compare the clinical characteristics of patients with Streptococcus milleri (SM) and Klebsiella spp. associated pyogenic liver abscess (PLA). METHODS: A retrospective study of patients with PLA due to SM and Klebsiella spp. was conducted. Clinical characteristics, laboratory and radiological features, management and outcomes were analyzed. RESULTS: From 2000 to 2009 inclusive, 21 and 140 patients had SM and Klebsiella spp. associated monomicrobial infected PLA, respectively. A higher incidence of active malignancy occurred in the SM group (14.3% vs. 3.6%, p < 0.03). The common clinical features of the patients were fever, chill and right upper quadrant pain. A longer duration (6.3 vs. 4.4 day, p = 0.04) of symptoms and a higher incidence of hepatomegaly (14.3% vs. 2.9%, p < 0.01) occurred in the SM group. Common laboratory and imaging abnormalities included: anemia, leukocytosis, high erythrocyte sedimentation rate and C-reactive protein, hypoalbuminemia, elevated total bilirubin and alanine aminotransferase, right hepatic lobe involvement, hypoechoic in ultrasonograpghy, rim enhancement and septal lobulation in computed tomography. The biliary tract disorder was the most common cause of the disease in the two groups. Patients with Klebsiella spp. associated PLA tended to have more complications: bacteremia (61.6% vs. 31.6%, p < 0.01) septic shock (33.6% vs. 19%, p = 0.11), disseminated intravascular coagulation (20.7% vs. 4.8%, p = 0.04), metastatic infections (10.7% vs. 0%, p = 0.06), acute renal and respiratory failure (5% vs. 0%, p = 0.14). However, both were effectively managed by the combination of antibiotics and image-guided aspiration with/without drainage, and their mortality rates were comparable to each other. Those patients with metastatic infection might need a longer duration (6.07 vs. 5.32 week, p = 0.144) of antibiotic therapy, which was due to the longer mean duration (3.85 vs. 2.86, p < 0.04) of an intravenous counterpart. CONCLUSION: SM associated PLA tends to have a distinct clinical syndrome as compared with that of Klebsiella spp. with regard to risk factors, clinical manifestations and complications. However, both can be effectively treated with a combination of antibiotics and image-guided aspiration with/without drainage.

Inflammatory index and treatment of brain abscess.

This study retrospectively analyzed 12 patients with brain abscesses. Half of the patients were diagnosed inaccurately in the initial stage, and 7.2 days were required to achieve the final diagnosis of brain abscess. The patients presented only with a moderately elevated leukocyte count, serum CRP levels, or body temperatures during the initial stage. These markers changed, first with an increase in the leukocyte count, followed by the CRP and body temperature. The degree of elevation tended to be less prominent, and the time for each inflammatory index to reach its maximum value tended to be longer in the patients without ventriculitis than in those with it. The causative organisms of a brain abscess were detected in 10 cases. The primary causative organisms from dental caries were Streptococcus viridians or milleri, and Fusobacterium nucleatum. Nocardia sp. or farcinica were common when the abscess was found in other regions. The primary causative organisms of unrecognized sources of infection were Streptococcus milleri and Prolionibacterium sp. Nocardia is resistant to many antibiotics. However, carbapenem, tetracycline and quinolone were effective for Nocardia as well as many other kinds of bacteria. In summary, the brain abscesses presented with only mildly elevated inflammatory markers of body temperature, leukocyte and CRP. These inflammatory markers were less obvious in the patients without ventriculitis and/or meningitis. The source of infection tended to suggest some specific primary causative organism. It was reasonable to initiate therapy with carbapenem.

Streptococcus anginosus group disseminated infection: case report and review of literature.

Streptococcus anginosus group is widely known for its ability to cause invasive pyogenic infections. There are very few reports of disseminated infections sustained by members of this streptococcal group. We report a case of a highly disseminated infection and analyse previous literature reports. Disseminated pyogenic infection has been defined as an infection affecting two or more of the following organs/systems: central nervous system, lung, liver and spleen. We performed a PubMed search using the terms: S. milleri, S. anginosus, brain abscess, pulmonary abscess, hepatic abscess, spleen abscess. We reviewed 12 case reports including the one presented in this paper. Underlying conditions such as dental infections, malignancy, gastrointestinal and respiratory tract disease accounted for 42% of cases. No definite endocarditis was encountered, even though positive blood cultures were found in 67% of patients. Concomitant brain-liver, brain-lung and brain-spleen involvement occurred in 50%, 42% and 8% of cases respectively. Ninety-one percent (91%) of patients were treated with ß-lactams, and surgical procedures were performed in 67% of patients. Infections caused by S. anginosus group members are satisfactorily treated with penicillin G and cephalosporins. It is very important to associate surgery to antimicrobial chemotherapy in order to achieve a full or nearly full clinical recovery.

Precipitating factors in the pathogenesis of peritonsillar abscess and bacteriological significance of the Streptococcus milleri group.

Peritonsillar abscess (PTA) is conventionally considered to be a complication of acute tonsillitis, but no pathogenical association has been demonstrated. To investigate the precipitating factors in the pathogenesis of PTA, the clinical status of 117 patients with PTA and 78 patients with peritonsillar cellulitis (PC) were reviewed, comparing them with 188 cases of acute tonsillitis as a control group. The period between the onset of symptoms and the date of starting hospitalized medication was 4 to 5 days in all the three groups, with no significant differences. Higher prevalence of smoking habit was noted in the PTA group (odds ratio, 1.92; 95% confidence interval, 1.17-3.16). Bacteriological culture revealed that 55 of 67 aerobic isolates were Streptococcus subspecies, with the Streptococcus milleri group (SMG) as the most common (20 isolates). Twenty-three anaerobic species were isolated. Only 51% of the patients with neither the SMG nor anaerobic bacteria were smokers, whereas 90% of the patients with both the SMG and anaerobic bacteria were smokers. We hypothesize that delay or failure to receive medical care do not contribute to the pathogenesis of PTA or PC, and that smoking is positively correlated with the occurrence of PTA, as well as the bacteriological character.

Streptococcus milleri group infection associated with digestive fistula in patients with vascular graft: report of seven cases and review.

We described seven patients with Streptococcus milleri group aortic (six patients) or vena cava (one patient) graft infection secondary to a vasculo-digestive fistula. Time between vascular graft setting and first clinical signs varied from eight months to more than thirteen years. Six patients had fever. Three patients presented with recurrent fever for more than nine months and in two of these cases, delay before diagnosis was long because repeated blood cultures were sterile. Three patients had abdominal pain and/or digestive haemorrhage. Abdominal CT-scan S. milleri was not contributive for the diagnosis in four patients. Streptococcus anginosus was isolated in four patients, Streptococcus constellatus in three patients. One patient died before surgical management. The other six patients were cured by a surgical management associated with a prolonged antibiotic (lactams) treatment. S. milleri group graft infections are rare (or misdiagnosed) while we found only 4 similar cases in the English medical literature. We conclude that a peri-prosthetic infection secondary to a digestive fistula must be insistently searched (and blood cultures must be repeated many times) in any patient with an aortic (or any other vascular) graft presenting prolonged or recurrent fever or acute digestive symptoms.

Empieza pleural causado por streptococcus milleri / No disponible

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Absceso cervical por Streptococcus angious-milleri tras ingestión de cuerpo extraño y sospecha de perforación esofágica / Cervical abscess by Streptococcus anginosus-milleri after foreign body ingestion and suspicion of esophageal perforation

Presentamos un caso de absceso cervical tras ingestión de cuerpo extraño (pollo con hueso) secundario a probable perforación esofágica que nos fue remitido con sospecha de complicación mediastínica. Se trataba de una chica de 17 años que nada más llegar a nuestro centro hospitalario requirió ingreso en UCI dada la gravedad de su proceso: Fiebre alta, dolor intenso cérvico-torácico, tumefacción láterocervical izquierda difusa de carácter progresivo y mal estado general. El TAC informó de la presencia de un absceso bien definido y de abundante componente aéreo que disecaba la musculatura cervical por lo que fue necesario realizar drenaje comprobando intraoperatoriamente la no afectación del mediastino. El cultivo de la colección purulenta reveló Streptococcus anginosus-milleri resistente a clindamicina pero sensible a penicilina y derivados. Realizamos una serie de consideraciones al respecto de este microorganismo y su significación clínica

We report a case of cervical abscess after the ingestion of foreign body (chicken bone) secondary to probable esophageal perforation that it was sent to us with suspicion of mediastinal complication. The girl, 17 years-old, nothing else to arrive our hospitalary center required entrance in ICU due to her severe clinical process: High rever, intense neck-thoracic pain, laterocervical diffuse and progressive left inflammation and bad general state. The CT showed the presence of a well defined abscess and abundant aerial component that dissected the cervical muscles that made necessary to perform drainage verifying intraoperatively no mediastinal involvement. The culture of the purulent collection revealed Streptococcus anginosus/milleri resistant to clindamicine but sensible to penicilina and derivatives. We exposed a serie of considerations at respect of such microorganism and its clinical signification

[Streptococcus milleri. An early sign of cancer in otorhinolaryngologic patients?]. / Streptococcus milleri. Ein Hinweis auf Karzinome im HNO-Bereich?

The Streptococcus milleri group, which also includes S. anginosus, S. intermedius and S. constellatus, is found in the oropharynx and gastrointestinal tract mucosa. Recent isolations of S. milleri DNA sequences have been made from both gastric and oesophageal carcinoma. There are only a few publications on the isolation of viable bacteria and S. milleri DNA, and their role in carcinogenesis, in otorhinolaryngologic malignoma. We present four patients with a cervical abscess and the isolation of S. milleri -group bacteria, without signs of malignancy or other risk factors. After a delay of several months, squamous cell carcinoma of the oropharynx was diagnosed in three patients and a neck metastasis without primary tumor in the fourth.

Meningitis y absceso cerebral por Streptococcus intermedius en un paciente con infección por VIH-1 / Meningitis and brain abscess caused by streptpcoccus intermedius in a patient infected with HIV-1

Los estreptococos de grupo milleri se caracterizan por su tendencia a provocar infecciones piógenas invasoras en diferentes localizaciones. Las meningitis estreptocócicas no neumocócicas son poco frecuentes en pacientes adultos y pueden asociarse a la presencia de un absceso cerebral. Los abscesos cerebrales son colecciones localizadas dentro del parénquima cerebral que se originan como complicación de una infección, siendo los estreptococos microaerófilos y las bacterias anaerobiaslos microorganismos más frecuentemente aislados. Aunque no es inusual la presencia de colecciones intracraneales de etiología infecciosa en pacientes con infección por VIH-1, los abscesos cerebrales producidos por las bacterias piógenas habituales son muy infrecuentes y es T. gondiiel agente etiológico más frecuente. Aportamos un caso de meningitis y absceso cerebral por S. intermedius en un paciente con infección por VIH-1

Streptococcus milleri group have been recognized as an important pathogens for abscess formation in various organs. Streptococci other than Streptococcus pneumoniae are a rare cause of bacterial meningitis in adults and can be associated with the presence of an undiagnosed brain abscess. Brain abscess is a focal collection within the brain parenchyma wich can arise as a complication of a variety of infections. The most common etiologic organisms in clinical series have been microaerophilic streptococci and anaerobic bacterias. Although intracraneal mass lesions that occur as a result of infection have commonly been reported in patients infected with the human immunodeficiency virus, brain abscess due to the common bacterial pathogens are rarely described in HIV infected patients and Toxoplasma gondii is the organism most frecuently isolated from stereotactic brain biopsy in these patients. We report a patient with both HIV-1 infection and streptococcal meningitis secondary to brain abscess caused by S. intermedius

The role of the capsule of the Streptococcus milleri group in its pathogenicity.

Study of the pathogenicity of encapsulated strains of the Streptococcus milleri group (SMG) was performed by examination of the ability to cause subcutaneous abscesses in mice and by phagocytosis and phagocytic killing of human polymorphonuclear neutrophils (PMNs) against the organisms. All 3 encapsulated isolates from patients with pneumonia or lung abscess induced abscesses in the mice; however, only 2 of 20 unencapsulated isolates from patients with lung abscess or thoracic empyema did so. The 3 encapsulated strains inhibited more phagocytosis and phagocytic killing of PMNs than the unencapsulated strains. In addition, encapsular material separated from Streptococcus constellatus RZYK001 also inhibited phagocytosis and phagocytic killing in proportion to increasing concentrations of the capsular material. These results suggest that capsular material produced by SMG might be a pathogenic factor.

Apical periodontitis development and bacterial response to endodontic treatment. Experimental root canal infections in monkeys with selected bacterial strains.

In six monkeys, 160 root canals were inoculated with a combination of four bacterial strains belonging to species Streptococcus milleri, Peptostreptococcus anaerobius, Prevotella oralis, and Fusobacterium nucleatum. In two other monkeys, 24 root canals were inoculated with a five-strain combination consisting of these strains and a strain of Enterococcus faecalis. All strains were previously isolated from an infected monkey root canal. After 8-12 months, survival of the strains was recorded bacteriologically, and the reaction in the periapical region was radiographed. From 180 of 184 root canals, one or more of the bacterial strains were reisolated. The two facultative strains were more frequently reisolated than the anaerobic strains. Apical periodontitis was registered in the periapical region of more than 96% of root canals with reisolated bacteria but in none of those without reisolated bacteria. Endodontic treatment was carried out in two sessions with an interval of 14 d without interappointment dressings, and the effect was evaluated bacteriologically before and after each treatment. The chemo-mechanical treatment reduced significantly the number of strains and bacterial cells. The facultative bacteria were more resistant to the treatment than the anaerobic bacteria. The five-strain combination had a higher survival rate than the four-strain combination.

Comparison between adult endocarditis due to beta-hemolytic streptococci (serogroups A, B, C, and G) and Streptococcus milleri: a multicenter study in France.

BACKGROUND: Limited data exist on infective endocarditis (IE) due to Streptococcus milleri (Sm) or beta-hemolytic streptococci (BHS). Because BHS and Sm share some physiologic and pathogenic properties, we wondered whether IE caused by these streptococci might present similarities. METHODS: Through a nationwide retrospective study in France, the medical and microbiologic charts of adults with definite Sm or BHS IE observed between January 1, 1991, and December 31, 1996, in university and general hospitals were reviewed. RESULTS: Fifty-six patients had BHS IE (33 men and 23 women; median age, 59 years; range, 18-91 years) and 29 had Sm IE (18 men and 11 women; median age, 66 years; range, 37-97 years). The BHS group tended to have more underlying medical conditions (46%) and fewer previous cardiopathies (48%) than the Sm group (28% and 71%, respectively). Multivariate analysis showed that a longer median time of IE evolution before diagnosis and identification of the presumed portal of entry were independently associated with Sm IE (P<.01). Extracardiac complications were more frequent in the BHS group (55%) than in the Sm group (39%). Comparison of echocardiographic findings between the 2 groups did not establish any statistically significant difference. Thirty-six patients (64%) in the BHS group and 18 (62%) in the Sm group underwent valve replacement. Overall, mortality was 27% for the BHS group and 14% for the Sm group. For all patients, multivariate analysis retained older age as the only significant risk factor for death (P =.01). CONCLUSION: Compared with Sm IE, BHS IE occurs in younger patients with more underlying diseases and fewer underlying cardiopathies and has a more aggressive presentation and evolution.

[Etiology of community-acquired pneumonia among adult patients in Japan].

To clarify the etiology of community-acquired pneumonia (CAP) in Japan, the causative pathogens were prospectively investigated in adult patients admitted to Kurashiki Central Hospital. The microbiological diagnosis was based on the results of quantitative sputum culture, blood culture, and other invasive procedures, including transthoracic needle aspiration or bronchoscopic examination. Five hundred fifty-two episodes of CAP in 540 patients were admitted between July 1994 and June 1999. Causative pathogens were identified in 353 episodes (63.9%). Several characteristics about the etiology of CAP in Japan were recognized: 1) Streptococcus pneumoniae is the most common pathogen followed by Haemophilus influenzae; 2) Mycoplasma pneumonia is dominant among young patients; 3) Chlomydia pneumoniae is one of the significant pathogens in Japan as well as in western countries; 4) Streptococcus milleri group and anaerobes are important pathogens in patients with suppurative pulmonary diseases; 5) The incidence of Legionella pneumonia is far lower than in western countries; 6) The prevalence of tuberculosis in CAP is still high in Japan; etc. Recognition of these results will lead us to treat patients with prompt antimicrobial therapy.