甘肃某地区奶牛运动场环境中耐药菌流行情况及相关耐药基因检测

为了解甘肃某地区奶牛运动场环境中主要耐药性细菌的分布情况及耐药基因的携带情况,试验采用抗性平板筛选法分离、纯化耐药菌后再通过16S rRNA鉴定;采用PCR方法检测6类22种耐药基因携带情况。结果显示,两年两个奶牛运动场(A和B)分离出不同种属的耐药菌共665株,经16S rRNA PCR鉴定主要为大肠杆菌、屎肠球菌和普通变形杆菌,其中耐药性大肠杆菌数量最多(398株),A牛场耐药菌数两年相比增长28.50%,B牛场耐药菌数量持平;通过对样品进行10类药物筛选耐药菌结果显示,耐药率前3位的分别为糖肽类(11.13%,74/665)、四环素类和磺胺类(10.98%,73/665)及β-内酰胺类和氨基糖苷类(10.23%,68/665)。采用PCR方法对样品进行耐药基因检测发现,两年两个奶牛运动场的耐药基因携带情况基本相同,喹诺酮类耐药基因qnrB、qnrS的携带率分别为10.81%和83.78%,磺胺类耐药基因Sul1、Sul2和Sul3的携带率分别为100%、100%和56.76%,糖肽类耐药基因VanA、VanB和VanC的携带率分别为78.38%、100%和100%,四环素类耐药基因tetA、tetB、tetC、tetM、tetO、tetL的携带率分别为100%、100%、100%、100%、81.08%和75.68%,KPC、NDM、aac(6′)-Ⅰb-cr耐药基因的携带率分别为32.43%、29.73%及24.32%,未检出qnrC、tetK、tetW、VIM和OXA耐药基因。携带耐药基因与GenBank中登录参考株基因序列的同源性为98%~99%。甘肃地区奶牛运动场中耐药菌对常用抗菌药物普遍耐药且携带相应耐药基因,奶牛运动场中碳青霉烯类及氨基糖苷类耐药基因与上年结果相比数量增加,各相关单位人员应对其加强奶牛场中耐药菌的监测,临床治疗中应合理用药,以降低环境中耐药菌转移给人类的潜在风险。

运动场环境对奶牛肢蹄健康的影响

试验研究运动场环境对于奶牛肢蹄健康的影响,对15户奶牛养殖户饲养的221头成年泌乳牛的饲养方式、运动场地面及运动场饲养密度进行调查,通过一般线性模型的单变量方差分析奶牛肢蹄健康情况与运动场环境的关系。结果显示:在运动场地面局部潮湿、干燥的情况下,运动场密度在12.3～33.4 m2/头范围时,其对奶牛肢蹄病发生无显著影响;而运动场地面为三合土、黄土、沙土及干粪时,其奶牛肢蹄病发病率极显著低于立砖地面的发病率。

The Moderating Effect of the Ski Resort Environment on the Skier’s Travel Radius under the Restriction of Skill Consumption

Starting from the skill characteristics of ski tourism,this paper discusses the impact of consumer skill on travel decisions,and the moderating effect of the ski resort’s comprehensive leisure environment(including the ski resort sports environment and the regional cultural tourism environment),in order to both understand their impacts on the travel distance characteristics of skiers and attempt to provide necessary research support for the development of China’s ski industry and the construction of destinations.Based on the data from multi-period visitor surveys,this paper constructs the consumption skill-travel radius decision-making influence model under the moderating effect of the ski resort comprehensive leisure environment.The results show three main characteristics.(1)The travel radius obviously differs among skiers with different skill levels.The skill level of skiers has a significant positive effect on the larger travel radius,and a significant negative effect on the smaller travel radius.That is,skiers with a higher skill level are more inclined to undertake long-distance skiing travel,while skiers with a lower skill level are more inclined to undertake short-distance skiing travel.(2)The comprehensive leisure environment has a significant moderating effect on the skiers’travel radius,with a significant positive impact on enlarging the travel radius,while the influences on high-skill and low-skill skiers are significantly higher than on middle-skill skiers.(3)In the comprehensive leisure environment,there are differences in the moderating effect of the ski resort sports environment and the regional cultural tourism environment on the skiers travel radius,and the positive moderating effect of the ski resort sports environment on the high-skill skiers’travel radius is more obvious.While the regional cultural tourism environment has a more obvious positive moderating effect on the travel radius of non-skiers and junior skiers,it is more conducive to promoting domestic travel.In general,the skier skill level in China was generally lower,and the ski resort comprehensive leisure environment optimization is conducive to overcoming the limitation of the travel radius caused by the disadvantageous skill level of consumers.However,to promote the development of China’s ski industry in the long run,it is necessary to focus on improving the consumer’s ski skill level,but prevent the risk of losing high-skill consumers overseas.In the course of improving the level of domestic ski sports facilities,we should also focus on the domestic leisure cultural tourism environment to better enhance the attractiveness of domestic ski destinations.

Effects of environmental variability and offspring growth on the movement ecology of breeding Scopoli＇s shearwater Calonectris diomedea

Most seabird species display colonial behavior during the breeding period which implies that food resources around breeding sites can easily go depleted. Seabirds need to both reach profitable areas, which can be located far from the colony, and return to the colony regularly. In this context, flexibility in movement behavior may be crucial for breeding success. During chick-rearing, Procellariformes species can alternate short trips lasting 1-4 days for chick provisioning with longer trips for self-provisioning in what has been called a dual-foraging strategy. We analyzed foraging trips from 136 Scopoli＇s shearwaters from three Mediterranean colonies tracked with GPS during 6 chick-rearing seasons to assess whether the adoption of a dual fo- raging strategy depends on the quality of habitat surrounding the colony. We found a marked dual-foraging strategy only in birds from the Linosa colony which was the largest colony in terms of breeding pairs and was characterized by having a lower marine habitat quality. Birds from this colony performed foraging trips that extended up to 369 km from the nest and lasted more than 10 days. In general, the decision to perform long lasting trips was triggered by lower values of primary production and higher offspring weight. Contrary to expectation, the decision to feed far from the colony was not related to the parents＇ weight. At the same time, despite the higher productivity offered by distant areas, the higher proportion of long trips performed by birds breeding in poor areas was not sufficient to maintain the same body mass as the ones breeding in richer areas [Current Zoology 60 （5）： 622-630, 2014].