A collection of 518 "Streptococcus milleri" isolates recovered from clinical specimens was identified to the species level according to recently established criteria. Streptococcus anginosus was the most frequently isolated species (59.3%), followed by S constellatus (30.3%) and S intermedius (10.4%). One third (34%) of all isolates were /3-hemolytic. The majority of S anginosus isolates were nonhemolytic, carried I.ancefield group F, or were nongroupable. Most of the 5 constellatus isolates were /3-hemolytic, as well as 16.6% of S intermedius strains. Streptococcus anginosus was recovered more often from the genital and urinary tracts and S constellatus was recovered from the thorax. Streptococcus intermedius was mostly found in the head and neck area, but was also isolated from the abdomen and the skin, bone, and soft tissue. Streptococcus intermedius and nonhemolytic isolates were recovered most often from abscess-related specimens. Strains belonging to the "Streptococcus milleri" group form a heterogeneous group within the viridans streptococci. They encompass organisms listed in the 1986 edition of Bergey's Manual 1 as S anginosus, Streptococcus MG, Sconstellatus, Sintermedius, "Smilleri, "and minute /3-hemolytic streptococci of Lancefield groups F and G 2 . Although the name "Streptococcus milleri" is not included in the approved lists of bacterial names, 3 the term remains popular because it conveys clinical significance. It refers to those viridans streptococci that may be associated with abscesses or other purulent infections. 4 Recent molecular studies clarified taxonomic relationships within the "Streptococcus milleri"group and Whiley and coworkers 5 redefined three species: S anginosus, S constellatus and S intermedius. In addition, they developed biochemical tests that allow for phenotypic differentiation between the three species. 6 In this study, we were interested in the clinical relevance of the three species within the "S milleri" group. We retrospectively identified a collection of 518 "S mil- From leri" isolates to the species according to Whiley and coworkers. 6 The collection consisted of mainly consecutive isolates from clinical specimens. We tried to establish possible associations between the distinct species, their anatomic distribution, and the relation with infection and abscesses. In addition, we described the hemolytic and serologic characteristics of the three species. MATERIALS AND METHODSThe streptococci studied were collected over a period of almost 3 years (July 1991-June 1994, and were consecutively recovered from clinical specimens routinely submitted for culture at the microbiological laboratory of the University Hospital of Maastricht (azM), a 600-bed tertiary care center. Streptococci were grown on blood agar base (Oxoid, Basingstoke, UK) containing 5% (v/v) sheep blood and on the same plates supplemented with nalidixic acid (5 mg/L) and polymixin B (10 mg/L). These plates were incubated in a C0 2 -enriched atmosphere and inspected for growth after 1 and 2 days. Blood wa...

During a 3-year study period, 19 patients at the University Hospital of Maastricht developed bloodstream infections with species of the "Streptococcus milleri" group, for an incidence of 0.33 per 1,000 admissions. The patients' median age was 48 years; the male-to-female ratio was 2.8. Eleven patients (57.9%) had underlying diseases, among which malignancy was predominant. Local trauma to the mucosal barrier was an important risk factor. An associated site of infection was found most frequently in the abdominal and thoracic cavities (nine and five cases, respectively). Bacteremia was polymicrobial in four of 19 episodes. The 20 infecting S. milleri strains were identified to the species level; Streptococcus anginosus was the most prevalent (16 strains). Eight strains carried Lancefield group C. The isolates were sensitive to most antibiotics. Abscess formation was documented in nine cases (47.3%); repeated drainage procedures were required in half of these episodes. Mortality was high (five of 19 patients, or 26.3%).

We conclude that hypothermic cardioplegic arrest during coronary artery bypass graft operations is associated with a transiently increased uptake and oxidation of carbohydrates during the immediate reperfusion phase.

In a double-blind randomized placebo-controlled study, the effects of intravenous glutamate infusion on myocardial haemodynamics and metabolism were studied in 22 patients undergoing routine coronary artery bypass graft (CABG) surgery. Immediately after aortic cross-clamp release, an intravenous infusion of a solution of glutamate (125 mmol x l(-1)) at a rate of 1.5 ml x h(-1) x kg(-1) was given over 1 h to 11 patients (G group). The other 11 patients received a placebo infusion (0.9% NaCl) (P group). Haemodynamic functions and rates of exchange of glucose, non-esterified fatty acids and lactic acid over the heart were measured before sternotomy (T1), 40 min after cross-clamp release (T2) and 4 h after cross-clamp release (T3). At T2, decreases were seen in comparison with T1 in systemic vascular resistance index, and increases were seen in cardiac index and coronary sinus flow. All of these changes were greater in the G group than in the P group (P<0.05). Myocardial glutamate consumption increased 2-fold after glutamate administration. No significant changes were observed in the myocardial utilization of glucose, lactate or non-esterified fatty acids between the P and the G groups at T1, T2 or T3. These data show that an intravenous glutamate infusion after routine CABG surgery significantly improved cardiac haemodynamic performance without direct effects on cardiac substrate metabolism. This suggests that a reduction of the afterload via a peripheral vasodilatory effect is the main mechanism leading to the observed changes in haemodynamics. Earlier claims that patients with post-operative cardiac failure show metabolic benefits from the glutamate infusion do not seem to apply to patients undergoing routine CABG surgery.

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