PCR primers specific for the Mycobacterium tuberculosis complex were used to detect the presence of Mycobacterium bovis BCG (Pasteur) in soil microcosms and Mycobacterium bovis in environmental samples taken from a farm in Ireland with a history of bovine tuberculosis. M. bovis genes were detected in soil at 4 and 21 months after possible contamination. Gene levels were found in the range of 1 ؋ 10 3 to 3.6 ؋ 10 3 gene copies g of soil ؊1 , depending on the sampling area. Areas around badger setts had the highest levels of detectable genes and were shown to have the highest levels of gene persistence. M. bovis-specific 16S rRNA sequences were detected, providing evidence of the presence of viable cells in Irish soils. Studies of DNA turnover in soil microcosms proved that dead cells of M. bovis BCG did not persist beyond 10 days. Further microcosm experiments revealed that M. bovis BCG survival was optimal at 37°C with moist soil (؊20 kPa; 30% [vol/wt]). This study provides clear evidence that M. bovis can persist in the farm environment outside of its hosts and that climatic factors influence survival rates.Environmental and wildlife reservoirs of Mycobacterium bovis are of significance due to the increasing number of bovine tuberculosis breakdowns in cattle herds in both the United Kingdom and Ireland. In Europe, the badger (Meles meles) has been implicated, but it is unclear how the disease is transmitted to cattle from badgers. Few studies have considered dissemination and persistence of environmental M. bovis. Tanner and Michel (12) reported survival of up to 6 weeks for M. bovis cells inoculated into soil and feces, detected by traditional selective cultivation methods. However, cultivation techniques for monitoring M. bovis and other mycobacteria in soil are impeded by the slow growth rates of M. bovis and the need for prolonged incubation of highly selective agars. Pretreatment or decontamination of samples is required involving the addition of 1 to 5% NaOH, often followed by further treatments with H 2
Background/Objectives To compare the effects of supplemental inorganic nitrate (NO3) on microvascular endothelial function and blood pressure in younger vs. older participants. Subjects/Methods 25 individuals participated in a double-blind, randomised, placebo-controlled crossover pilot study. Participants were stratified by age (18–35 and ≥55 years) and consumed a single dose beetroot juice (providing 6.4 mmol NO3) or NO3-depleted beetroot juice. Blood pressure, microvascular function (via Laser Doppler Flowmetry; LDF) and urinary NO3 were assessed, and the effects of NO3 supplementation on cardiovascular parameters were compared between participants and conditions using mixed-design ANOVA. Results Treatments and methods were well tolerated, and no adverse events were reported. Urinary NO3 increased 3 h following ingestion in both groups, (P = 0.02). Levels remained elevated at 24 h post consumption in younger participants only (P = 0.02). Beetroot juice had no effect on blood pressure in either group nor on microcirculatory endothelial function. Conclusions Beetroot juice had no effect on blood pressure or microvascular endothelial function in young and older individuals. Dosage and timing regimens for supplemental beetroot juice should be avenues for further inquiry.
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