Quantitative bacteriological analysis of the aerobic fecal microflora of 75 patients indicated that, at the time of admission to hospital, Escherichia coli were the predominant fecal aerotolerant bacteria. Subsequent fecal samples showed a progressive supplantation of E coli by Klebsiella, Enterobacter and Proteus. At the end of 21 days of hospitalization, E coli remained predominant in only 30 patients. None of the patients had received antibiotics, undergone surgery or been subjected to x-ray studies of the gastrointestinal tract. The cause of the change of fecal flora in these patients is unknown, and no change of flora was observed in a control group of nonhospitalized persons, also studied for 21 days. The appearance of Klebsiella, Enterobacter and Proteus as predominant in the fecal flora of hospitalized patients may be an important factor in the natural history of hospital-associated infections.

Bacteria↗

PubMedDate not supplied

The relation between aerobic fecal and oropharyngeal microflora in hospitalized patients.

The aerobic fecal and oropharyngeal bacterial flora was examined in 75 patients hospitalized, but not given antibiotics; in 70 patients given antibiotics during hospitalization and in 25 nonhospitalized controls. In all subjects, when first examined, normal throat flora were predominant. At the end of 21 days, however, a gram-negative bacilli became predominant in 17 (22.7%) of the Hospital Group and 33 (47.1%) of the Antibiotic Group. Newly appearing genera of gram-negative bacilli in the pharynx were almost always represented those present in the fecal flora. The Hospital Group all had recognizable components of the normal oropharyngeal flora present at 21 days, but 12 (17.1%) of the Antibiotic Group had no demonstrable normal oropharyngeal flora at 21 days. The findings suggest that hospitalization alone can be associated with the appearance of gram-negative bacilli in the oropharynx, and that the intestinal tract is their most likely point of origin.

Anti-Bacterial Agents↗

PubMedDate not supplied

Life expectancy estimation with breast cancer: bias of the declining exponential function and an alternative to its use.

BACKGROUND: Life expectancy gain (LEG) is an outcome measure commonly estimated with a declining exponential function in a Markov model. The accuracy of such estimates has not been objectively evaluated. PURPOSE: To compare LEGs from declining exponential function estimates with those calculated from population data, using published screening mammography studies as examples. METHOD: SEER-based population data are used to compare LEG calculation with declining exponential function estimation and empiric population data in a new model, the "nested" Markov. RESULTS: Analyses of the LEG of mammographic screening based on the declining exponential function significantly overestimate LEGs for younger women and underestimate them for older women. Because of offsetting errors, all-age analyses paradoxically appear accurate. CONCLUSION: Declining exponential function estimates of LEGs for chronic diseases with low mortality rates and long time horizons are liable to significant bias, especially with limited age cohorts.

Adult↗