Selective suppression of alimentary tract microbial flora as prophylaxis during granulocytopenia.

Oral nonabsorbable antibiotics have been used to suppress the rectal flora in granulocytopenic patients. Problems with these therapies, i.e., compliance, acquisition of undesirable flora, and cost, motivated the search for an alternative therapy which would increase compliance and effectively reduce the Enterobacteriaceae without creating a microbiol vacuum. Trimethoprim-sulfamethoxazole was found to be easily taken, to suppress the Enterobacteriaceae, and to maintain the anaerobic rectal flora for biological stability of the rectal ecosystem. However, concurrent use of parenteral antibiotics profoundly influenced rectal flora and temporarily destroyed the colonization resistance afforded by the anaerobes.

A comparison of trimethoprim-sulfamethoxazole plus nystatin with gentamicin plus nystatin in the prevention of infections in acute leukemia.

Fifty-three profoundly granulocytopenic patients with relapsed acute leukemia who were undergoing reinduction chemotherapy were prospectively randomized to receive either trimethoprim-sulfamethoxazole plus nystatin or gentamicin plus nystatin for prevention of infections. The acquisition of new organisms per patient during the total study period was similar in both groups. Thirty-five symptomatic infections (five of which were bacteremias) occurred in patients receiving trimethoprim-sulfamethoxazole plus nystatin, whereas 31 infections (eight bacteremias) occurred in patients receiving gentamicin plus nystatin. Four deaths related to infection occurred in patients taking trimethoprim-sulfamethoxazole, and eight occurred in patients taking gentamicin. We conclude that trimethoprim-sulfamethoxazole plus nystatin was approximately as effective as gentamicin plus nystatin for prophylaxis against infection in relapsed acute leukemia. Furthermore, side effects were fewer and compliance was better with trimethoprim-sulfamethoxazole plus nystatin.

Aspergillus vegetative endocarditis and complete heart block in a patient with acute leukemia.

Aspergillus flavus vegetative endocarditis together with myocardial abscesses and pneumonitis developed in a patient with acute lymphocytic leukemia. The initial diagnosis was not suspected until 67gallium imaging revealed a radiographically undetectable thoracic abnormality. Despite apparently "early" diagnosis, antifungal therapy was inadequate to prevent disruption of the bundle of His, complete heart block and death.

Effect of physical parameters on the in situ survival of Escherichia coli MC-6 in an estuarine environment.

Survival of Escherichia coli MC-6 of fecal origin in an estuarine environment as affected by time, water temperature, dissolved oxygen, salinity, and montmorillonite in diffusion chambers has been elucidated. Several in situ physical parameters were recorded simultaneously, and viable cell numbers were estimated. The survival of the bacteria varied seasonally. Montmorillonite addition extended the time needed for a 50% reduction of the viable cell population (t1/2) of cells by 40% over the t1/2 of cells in Rhode River water alone. The effect of this clay was not significantly greater between 50- to 1,000 mug/ml montmorillonite concentrations. In all experiments, the relationships among pairs of variables were studied by regression and correlation analysis. The slope between viable cell numbers and water temperatures increased about 50% for each 10 C increment in temperature and gave a correlation coefficient r = 0.617, significant at 95% confidence level. A similar correlation coefficient, r = 0.670, was obtained between water temperature and t1/2 of the initial cell population. In all experiments regressions were performed considering all variables after bacteria had been in the Rhode River environment for 3 days. Coefficient of multiple determination was estimated as R2 = 0.756. Approximately 75.6% of the variance of viable cell numbers can be explained by variation in water temperature, dissolved oxygen, and salinity. Simple correlation coefficients within the regression steps were also computed. Survival of bacteria was closely and negatively correlated with increasing water temperature (r = -0.717). It is suggested that water temperature is the most important factor in predicting fecal coliform survival from point and nonpoint sources in assessing water quality in an estuarine ecosystem.