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 β-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.

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.

[Streptococcus milleri. An early sign of cancer in otorhinolaryngologic patients?]

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.

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.

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.

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.