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Of 46 viridans streptococci isolated from cases of probably true bacteremia, 26 strains or 56% could be grouped serologically in the Lancefield system. Eight strains (17%) were identified as serogroup H (characteristic of Streptococcus sanguis), ten strains (22%) as serogroup W (a new group antigen found in S. sanguis) and eight strains (17%) as serogroup K (related to S. mitis (mitior)). The high number of serogroupable viridans streptococci was specially due to the introduction of serogroup W and indicates the importance of this serogroup in cases of bacteremia. A set of six diagnostic tests (production of hydrogen peroxide, arginine and esculin hydrolysis, polysaccharide production, Voges-Proskauer reaction, mannitol fermentation) was used for speciation of the viridans streptococci; in addition, search for spreading zones around the colonies was included in the diagnostic procedure. Spreading zones were only present in S. sanguis and occurred more frequently in group H strains than group W strains. The 46 viridans streptococci were tested in genetic transformation. The prevalence of spontaneous competence in strains isolated from the blood was high, particularly in S. sanguis serogroup H (88%) and W (50%). For serogroup H, spontaneous competence was found as frequently among invasive strains as among carrier isolates previously studied.

Streptococcus sanguis (serogroups H and W) strains are frequently competent in genetic transformation. In a collection of 18 strains of S. sanguis isolated from blood cultures, 12 strains were spontaneously competent in transformation by streptomycin-resistant DNA, and three strains were induced to competence by the use of culture filtrates containing competence factor (CF). Culture filtrates from spontaneously competent S. sanguis strains only induced competence in transformation of strains of the same species. In addition to the three "constitutional" types of S. sanguis with regard to specificity of transformation previously reported (originally represented by the strain Challis, 13b and NCTC 7863), a possible fourth type, (represented by strain 21452) was found. Further studies are required to ascertain the role of these types. The "constitutional" types are characterized by the range of activity of their CF's. These specificities seem useful in identification of S. sanguis and its separation from S. mitis (mitior). Tests of spontaneously competent strains with culture filtrates from other competent strains showed variable effects on the transformation frequencies in different strains.

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We describe the symptomatology of different disease entities caused by group A beta-hemolytic streptococci (Streptococcus pyogenes, GAS). The case histories of four patients, two of whom died, emphasize the severity of certain clinical manifestations of GAS-infections. A 34 year-old woman was admitted to hospital four days after start of the symptoms. She presented a clinical picture very similar to that observed in fulminant meningococcal septicaemia; i.e. extensive skin haemorrhages, circulatory collapse, and multiple organ failure. She died within 12 hours of admission. GAS were isolated in blood culture. A seven day-old girl died before admission to hospital. GAS were isolated in blood cultures, cerebrospinal fluid and from her nose and throat. An eight year-old, psychomotoric retarded girl developed a severe left-sided pneumonia, empyema and scarlatina. GAS were detected in throat culture. She responded poorly to high doses of benzylpenicillin given intravenously. She recovered rapidly after thoracotomy and decortication of her left lung. Finally, we describe the case of an 11 year-old boy with rheumatic fever without cardiac involvement. The reported cases underline the need for careful diagnosis and penicillin treatment in cases of GAS-infections.

Counterimmunoelectrophoresis (CIE) and fluorescent antibody (FA) technique were evaluated in the diagnosis of bacterial meningitis caused by Neisseria meningitidis (groups A, B, C), Streptococcus pneumoniae and Haemophilus influenzae type b. FA was positive in 80% and CIE in 70% of the 59 cases of bacterial meningitis investigated. Ultrasonic treatment of the cerebrospinal fluid (CSF) increased the efficacy of CIE from 50% to 70%. By FA it was possible to demonstrate bacterial antigen in CSF up to 3 days after the beginning of antibacterial therapy. Bacterial antigens could be demonstrated by the two immunological methods from 2 to 24 days when stored at 20 degrees C. At storage at 4 degrees C the antigens were demonstrable for 2 to 13 weeks by FA and for 2 to 10 weeks by CIE.

Plasma LPS were quantitated in 40 patients with bacteriological verified systemic meningococcal infection (SMD). Twenty-two patients (55%) demonstrated LPS greater than 25 pg/ml. Fourteen patients with initial plasma LPS levels greater than 700 pg/ml developed a severe septic shock, impaired renal function and extensive coagulopathy compared to 2 out of 26 patients with LPS levels below 700 pg/ml. Seven patients died due to the circulatory collapse and multiple organ failure all with initial LPS levels greater than 1,000 pg/ml. Initiation of antibiotic therapy did not result in further increase of plasma LPS concentration. LPS were cleared from the circulation with a half-life of 1.5-3 hours after initiation of antibiotic treatment with penicillin and chloramphenicol. The results suggest that plasma LPS are quantitatively related to the development of septic shock, multiple organ failure and death from these complications in SMD, making LPS measurement a direct prognostic marker.

Since 1987 the number of severe and fatal cases of group A-beta-hemolytic streptococci (GAS) infections has increased in Scandinavia. It therefore seems reasonable to stress the monitoring, diagnosis and treatment of infections caused by GAS. Treatment with phenoxymethylpenicillin for ten days is recommended for patients with uncomplicated disease. Patients with severe disease should be treated with benzylpenicillin intravenously. We discuss alternative antibiotics, treatment of immunological complications, and general hygienic precautions.

Two different methods of inoculum preparation for susceptibility testing were analysed. The first method was adjustment of inoculum size by haemocytometer counting. The second method was spectrophotometric adjustment at 530 nm. The reliability of both methods was assessed by colony counting. The overall agreement between colony counting and haemocytometer counts was 93.6%, and the intraclass coefficient correlation was 0.71 (P < 0.05). Pearson's correlation index between colony counts and optical density values was -0.059 (P > 0.05). Optical densities ranged between 0.01 and 1.2, showing less reproducibility than expected by the NCCLS M38-P standard. Haemocytometer counting is a more reliable method of inoculum preparation for antifungal susceptibility testing.