Accurate assessment of health risks associated with bovine (cattle) fecal pollution requires a reliable host-specific genetic marker and a rapid quantification method. We report the development of quantitative PCR assays for the detection of two recently described bovine feces-specific genetic markers and a method for the enumeration of these markers using a Markov chain Monte Carlo approach. Both assays exhibited a range of quantification from 25 to 2 ؋ 10 6 copies of target DNA, with a coefficient of variation of <2.1%. One of these assays can be multiplexed with an internal amplification control to simultaneously detect the bovine-specific genetic target and presence of amplification inhibitors. The assays detected only cattle fecal specimens when tested against 204 fecal DNA extracts from 16 different animal species and also demonstrated a broad distribution among individual bovine samples (98 to 100%) collected from five geographically distinct locations. The abundance of each bovine-specific genetic marker was measured in 48 individual samples and compared to quantitative PCR-enumerated quantities of rRNA gene sequences representing total Bacteroidetes, Bacteroides thetaiotaomicron, and enterococci in the same specimens. Acceptable assay performance combined with the prevalence of DNA targets across different cattle populations provides experimental evidence that these quantitative assays will be useful in monitoring bovine fecal pollution in ambient waters.
Lung transplantation with its attendant life-long immunosuppression contributes to bone loss and its sequelae, fractures and kyphosis, in patients with lung disease, many of whom already suffer from severe osteoporosis. Patients with cystic fibrosis (CF) are one of the most severely affected groups. We conducted a controlled, randomized, nonblinded trial of pamidronate (30 mg intravenously every 3 mo) with vitamin D (800 IU/d) and calcium (1 g/d) (n = 16) compared with vitamin D and calcium alone (n = 18, the control subjects) for 2 yr in 34 patients after lung transplant to improve bone mineral density (BMD). The treatment groups were similar in age, sex, baseline T-scores, renal function, hospitalization rates, immunosuppressant levels, change in lung function, and body mass index (BMI) over the study period. The patients treated with pamidronate gained 8.8 +/- 2.5% and 8.2 +/- 3.8% in spine and femur BMD after 2 yr in comparison to control subjects, who gained, on average (+/- SD), 2.6 +/- 3.2 and 0.3 +/- 2.2%, respectively (p = 0.015 for both). Seven and six fractures occurred in the control and pamidronate groups, respectively (p > 0.2). Measures of bone resorption were highest immediately after lung transplant and improved with both pamidronate and time. Measures of bone formation were very poor after lung transplant, but recovered in the first post-lung transplant year irrespective of therapy. We conclude that pamidronate was more effective than control in improving bone mineral density after lung transplantation in patients with CF and appears to be one of the most promising agents studied to date for posttransplant osteoporosis.
Assays for the detection and typing of adenoviruses, enteroviruses and F+ specific coliphages were performed on samples created as part of a national microbial source tracking methods comparison study. The samples were created blind to the researchers, and were inoculated with a variety of types of fecal contamination source (human, sewage, dog, seagull and cow) and mixtures of sources. Viral tracer and pathogen assays demonstrated a general ability to discriminate human from non-human fecal contamination. For example, samples inoculated with sewage were correctly identified as containing human fecal contamination because they contained human adenovirus or human enterovirus. In samples containing fecal material from individual humans, human pathogen analysis yielded negative results probably because the stool samples were taken from healthy individuals. False positive rates for the virus-based methods (0-8%) were among the lowest observed during the methods comparison study. It is suggested that virus-based source tracking methods are useful for identification of sewage contamination, and that these methods may also be useful as an indication of the public health risk associated with viral pathogens. Overall, virus-based source tracking methods are an important approach to include in the microbial source tracking 'toolbox'.
Vitamin D2 absorption was significantly lower in CF patients than in control subjects. These results may help explain the etiology of vitamin D deficiency in CF patients, which may contribute to their low BMD.
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