Evaluation of recovery methods to detect faecal streptococci in polluted waters.

AIMS: This paper compares the faecal streptococci count on 25 samples of polluted waters obtained with three techniques: most probable number (MPN), membrane filtration (MF) and pour plate (PP) methods. Although the PP method is a simple technique, familiar to water bacteriologists, it is not recommended in the international methods. METHODS AND RESULTS: For the MPN method, azide dextrose broth and ethyl violet azide broth were employed. For the MF technique, Millipore filters were placed onto azide maltose agar (KF agar), while for the PP method, 1 ml of a decimal water dilution was added to (Kennel Faecal) KF medium. Regression analysis and Friedman's ANOVA were performed to determine the relationship between faecal streptococci counts obtained with the three techniques. Statistical analysis of the results showed that the MPN, MF and PP techniques were equally valid with respect to faecal streptococci enumeration in polluted waters. CONCLUSION: Since the PP method was found to be as good as the other techniques, it may be preferred in polluted waters. It is more economical in terms of both time and materials than the MPN count, and it is as accurate as the MF count. SIGNIFICANCE AND IMPACT OF THE STUDY: This study indicates that the PP method, although not recommended internationally, is a reliable alternative to MF and MPN.

[Clinical results and modification of left ventricular function after emergency revascularization for acute myocardial infarction]. / Risultati clinici e modificazioni della funzione ventricolare sinistra dopo rivascolarizzazione d'emergenza per infarto miocardico acuto.

Results of emergency revascularization for evolving myocardial infarction have been evaluated in 43 consecutive patients operated between January 1985 and March 1988. Time interval between onset of symptoms and coronary bypass averaged 6.7 +/- 0.5 hours (0.75-48). Intravenous or intracoronary thrombolysis was attempted pre-operatively in 26 cases. Overall hospital mortality was 6.9% (3/43) but this decreased to only 2.7% if patients in cardiogenic shock were excluded. Follow-up averaged 20.6 +/- 9.5 months (4-42). Actuarial survival was 82.9 +/- 7.3% at 36 months. Of the 36 survivors, 28 were free from angina and reinfarction at control. Nineteen patients were evaluated with angiography at follow-up (averaging 10.1 +/- 5.7 months). Left ventricular and regional ejection fraction were calculated on pre- and post-operative angiograms; regional ejection fraction was determined with the centerline method. Left ventricular ejection fraction increased from 0.49 +/- 0.15 to 0.52 +/- 0.19 (NS), regional ejection fraction improved from 0.20 +/- 0.1 to 0.27 +/- 0.16 (35% increment, p less than 0.05). The analysis of left ventricular and regional ejection fraction variations with the time elapsed from the onset of symptoms to surgery identified two subgroups of patients: those operated within and after six hours. In the first subgroup, left ventricular ejection fraction increased from 0.52 +/- 0.16 to 0.62 +/- 0.13 (p less than 0.005) and regional ejection fraction from 0.19 +/- 0.08 to 0.36 +/- 0.14 (89% increment, p less than 0.0005). In the second subgroup, both left ventricular and regional ejection fractions decreased from 0.44 +/- 0.13 to 0.36 +/- 0.11 (NS) and from 0.20 +/- 0.13 to 0.12 +/- 0.08 (NS), respectively. These results lead to the conclusion that improved left ventricular performance may be achieved in selected groups of patients if they undergo surgery within six hours of the onset of pain.