Stanford K, Reuter T, Gilroyed B H, McAllister T A
Alberta Agriculture and Rural Development, Lethbridge, AB, Canada.
J Appl Microbiol. 2015 Apr;118(4):989-97. doi: 10.1111/jam.12749. Epub 2015 Feb 4.
To investigate impact of sporulation and compost temperatures on feasibility of composting for disposal of carcasses contaminated with Bacillus anthracis.
Two strains of B. cereus, 805 and 1391, were sporulated at either 20 or 37°C (Sporulation temperature, ST) and 7 Log10 CFU g(-1) spores added to autoclaved manure in nylon bags (pore size 50 μm) or in sealed vials. Vials and nylon bags were embedded into compost in either a sawdust or manure matrix each containing 16 bovine mortalities (average weight 617 ± 33 kg), retrieved from compost at intervals over 217 days and survival of B. cereus spores assessed. A ST of 20°C decreased spore survival by 1·4 log10 CFU g(-1) (P < 0·05) compared to a 37°C ST. Spore survival was strain dependent. Compost temperatures >55°C reduced spore survival (P < 0·05) and more frequently occurred in the sawdust matrix.
Sporulation and compost temperatures were key factors influencing survival of B. cereus spores in mortality compost.
Composting may be most appropriate for the disposal of carcasses infected with B. anthracis at ambient temperatures ≤20°C under thermophillic composting conditions (>55°C).
研究芽孢形成和堆肥温度对炭疽芽孢杆菌污染尸体堆肥处理可行性的影响。
蜡样芽孢杆菌的两株菌株805和1391分别在20℃或37℃（芽孢形成温度，ST）下形成芽孢，将7 Log10 CFU g(-1)的芽孢添加到尼龙袋（孔径50μm）或密封小瓶中的高压灭菌粪便中。小瓶和尼龙袋分别埋入锯末或粪便基质的堆肥中，每种基质均含有16头牛尸体（平均体重617±33 kg），在217天内定期从堆肥中取出，评估蜡样芽孢杆菌芽孢的存活率。与37℃的芽孢形成温度相比，20℃的芽孢形成温度使芽孢存活率降低了1·4 log单位CFU g(-1)（P < 0·05）。芽孢存活率因菌株而异。堆肥温度>55℃会降低芽孢存活率（P < 0·05）且在锯末基质中更频繁出现。
芽孢形成和堆肥温度是影响蜡样芽孢杆菌芽孢在尸体堆肥中存活的关键因素。
在嗜热堆肥条件（>55℃）下，堆肥可能最适合处理在环境温度≤20℃时感染炭疽芽孢杆菌的尸体。
