Impact of temperature and soil type on Mycobacterium bovis survival in the environment
Impact of temperature and soil type on Mycobacterium bovis survival in the environment
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DOI：
10.1371/journal.pone.0176315
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发表时间：
2017-04-27
期刊：
影响因子：
3.7
通讯作者：
Hartmann, Alain
中科院分区：
文献类型：
--
作者：
Barbier, Elodie;Rochelet, Murielle;Hartmann, Alain
牛结核分枝杆菌（Mycobacterium bovis）是牛结核病（botuberculosis，bTB）的病原体，主要影响牛，其天然宿主，但也影响广泛的家养和野生哺乳动物。除了通过污染的气溶胶直接传播外，M。野生动物和牲畜之间的牛感染可能通过吸入或摄入受感染动物脱落污染的环境基质而发生。我们监测了M的生存情况。牛在两个土壤样品选择其对比的物理和化学性质（即pH值，粘土含量）。M的人口。在4 ℃和22 ℃下孵育14、30、60、90、120和150天后，通过基于培养的方法对加标在无菌土壤中的牛进行计数。还进行了靶向IS1561'基因座的基于qPCR的测定以监测M。牛在无菌和生物掺加土壤。用培养法分析存活曲线表明，M。牛在较低温度下存活时间更长（4摄氏度对22摄氏度），而土壤特性对M.牛的持久性不明显。此外，基于qPCR的测定检测到M.牛的时间比基于培养的方法更长，在无菌土壤中观察到的基因拷贝数比在生物土壤中观察到的更高。土壤类型对M.牛的持久性需要加深，以填补有关疾病间接传播知识的差距。
Mycobacterium bovis, the causative agent of the bovine tuberculosis (bTB), mainly affects cattle, its natural reservoir, but also a wide range of domestic and wild mammals. Besides direct transmission via contaminated aerosols, indirect transmission of the M. bovis between wildlife and livestock might occur by inhalation or ingestion of environmental substrates contaminated through infected animal shedding. We monitored the survival of M. bovis in two soil samples chosen for their contrasted physical and-chemical properties (i.e. pH, clay content). The population of M. bovis spiked in sterile soils was enumerated by a culture-based method after 14, 30, 60, 90, 120 and 150 days of incubation at 4 degrees C and 22 degrees C. A qPCR based assay targeting the IS1561' locus was also performed to monitor M. bovis in both sterile and biotic spiked soils. The analysis of survival profiles using culture-based method showed that M. bovis survived longer at lower temperature (4 degrees C versus 22 degrees C) whereas the impact of soil characteristics on M. bovis persistence was not obvious. Furthermore, qPCR-based assay detected M. bovis for a longer period of time than the culture based method with higher gene copy numbers observed in sterile soils than in biotic ones. Impact of soil type on M. bovis persistence need to be deepened in order to fill the gap of knowledge concerning indirect transmission of the disease.