Seasonal epidemiology of gastrointestinal nematodes of cattle in the northern continental climate zone of western Canada as revealed by internal transcribed spacer-2 ribosomal DNA nemabiome barcoding.
Seasonal epidemiology of gastrointestinal nematodes of cattle in the northern continental climate zone of western Canada as revealed by internal transcribed spacer-2 ribosomal DNA nemabiome barcoding.
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DOI：
10.1186/s13071-021-05101-w
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发表时间：
2021-12-11
影响因子：
3.2
通讯作者：
Gilleard JS
中科院分区：
文献类型：
--
作者：
Wang T;Redman EM;Morosetti A;Chen R;Kulle S;Morden N;McFarland C;Vineer HR;Colwell DD;Morgan ER;Gilleard JS
由于全球变暖和新出现的驱虫药耐药性等因素，世界许多地区的胃肠道线虫(GIN)流行病学正在发生变化。然而，由于缺乏经验数据，人们对北部大陆性气候带这些变化的动态了解很少。本文研究了自然感染放牧牛粪便中不同种类杜松子酒自由生活感染三期幼虫(L3)在牧场上的积累。这项实地研究在加拿大西部艾伯塔省的三个有机农场进行。从每个农场的三个不同牧场的每个牧场采集了24个粪便样本。用内转录间隔物-2线虫代谢编码来确定收获幼虫的杜松子种组成。牛的轮流放牧模式确保了每个牧场只被粪便拍打沉积污染一次。这一设计使我们能够在自然气候条件下监测特定杜松子酒品种在牧场上的L3积累，而不会受到牧场再污染或驱虫处理的混杂影响。在9个牧场中，有7个牧场的草L3计数在粪便沉积后约9周达到峰值，然后逐渐下降。然而，在放牧季节结束时，粪便中残留了较多的L3。线虫代谢物编码表明，在所有牧场上最丰富的两个物种是凤尾草和玉米草，幼虫在草地上的积累动态相似。在整个采样期内，大部分牧场的日降雨量和气温都是相似的，多元线性回归表明，样本采集前1周的累积降雨量对牧场L3种群有显著影响，而样本采集前3周的累积降雨量对牧场L3种群没有显著影响。结果表明，短时小气候条件改变了草地L3种群，有利于向草地的水平迁移。总体而言，研究结果显示了粪便PAT作为加拿大西部牧场L3级杜松子牛的避难所和贮藏室的重要性，并为该地区轮牧管理的风险评估提供了证据基础。网上版载有补充材料，可在10.1186/s13071-021-05101-w查阅。
Gastrointestinal nematode (GIN) epidemiology is changing in many regions of the world due to factors such as global warming and emerging anthelmintic resistance. However, the dynamics of these changes in northern continental climate zones are poorly understood due to a lack of empirical data. We studied the accumulation on pasture of free-living infective third-stage larvae (L3) of different GIN species from fecal pats deposited by naturally infected grazing cattle. The field study was conducted on three organic farms in Alberta, western Canada. Grass samples adjacent to 24 fecal pats were collected from each of three different pastures on each farm. Internal transcribed spacer-2 nemabiome metabarcoding was used to determine the GIN species composition of the harvested larvae. The rotational grazing patterns of the cattle ensured that each pasture was contaminated only once by fecal pat deposition. This design allowed us to monitor the accumulation of L3 of specific GIN species on pastures under natural climatic conditions without the confounding effects of pasture recontamination or anthelmintic treatments. In seven out of the nine pastures, grass L3 counts peaked approximately 9 weeks after fecal deposition and then gradually declined. However, a relatively large number of L3 remained in the fecal pats at the end of the grazing season. Nemabiome metabarcoding revealed that Cooperia oncophora and Ostertagia ostertagi were the two most abundant species on all of the pastures and that the dynamics of larval accumulation on grass were similar for both species. Daily precipitation and temperature across the whole sampling period were similar for most of the pastures, and multiple linear regression showed that accumulated rainfall 1 week prior to sample collection had a significant impact on the pasture L3 population, but accumulated rainfall 3 weeks prior to sample collection did not. The results suggest that the pasture L3 population was altered by short-term microclimatic conditions conducive for horizontal migration onto grass. Overall, the results show the importance of the fecal pat as a refuge and reservoir for L3 of cattle GIN on western Canadian pastures, and provide an evidence base for the risk assessment of rotational grazing management in the region. The online version contains supplementary material available at 10.1186/s13071-021-05101-w.
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DOI：
10.1016/j.cvfa.2019.11.008
发表时间：
2020-03-01
影响因子：
4.1
作者：
Hildreth, Michael B.;McKenzie, John B.
通讯作者：
McKenzie, John B.
影响因子：
48
作者：
Callahan BJ;McMurdie PJ;Rosen MJ;Han AW;Johnson AJ;Holmes SP
通讯作者：
Holmes SP
影响因子：
2.6
作者：
Eysker, M;van der Aar, WM;Kooyman, FNJ
通讯作者：
Kooyman, FNJ
影响因子：
2.4
作者：
GRENFELL, BT;SMITH, G;ANDERSON, RM
通讯作者：
ANDERSON, RM
影响因子：
3.7
作者：
Kim ES;Sonstegard TS;da Silva MV;Gasbarre LC;Van Tassell CP
通讯作者：
Van Tassell CP