犬科动物粪便菌群组成及多样性分析

【作者】 曹先海；

【导师】 张洪海；

【作者基本信息】 曲阜师范大学 ， 野生动植物保护与利用， 2011， 硕士

【摘要】 犬科动物是食肉目动物中分布最为广泛的类群,几万年前就与人类生活在一起,二者之间有着不可分割的联系。在犬科动物的研究过程中,其消化生理学领域的研究非常重要,特别是消化道菌群生态方面的研究早已成为学术界的热点话题。目前国内外对家犬肠道正常微生物的研究相对比较深入,但对于其他生存在野外环境下的犬科动物的消化道菌群的的组成及多样性研究较少。为了解犬科动物的消化道菌群组成及多样性特征,本文应用传统培养方法对五种犬科动物(狼、赤狐、沙狐、乌苏里貉和豺)粪便内微生物菌群组成和多样性进行研究,通过与已报道的家犬肠道菌群进行对比分析,全面展现犬科动物肠道正常微生物菌群组成、群落结构及微生态平衡,为犬科动物粪便菌群的研究积累基础资料,并为研究犬科动物肠道微生态环境和肠道疾病提供科学依据。根据菌落形态、革兰氏染色特性和显微镜镜鉴,从狼(Canis lupus)粪便菌群中分离到45株菌,赤狐(Vulpes vulpes)粪便菌群中33株菌,沙狐(Vulpes corsac)粪便菌群中27株菌,乌苏里貉(Nyctereutes procyonoides)粪便菌群中38株菌,豺(Cuon alpinus)粪便菌群中39株菌。结合生理生化实验结果,根据细菌鉴定相关资料综合判断,最终确定狼粪便菌群中有22个菌属,赤狐粪便菌群中有19个菌属,沙狐粪便菌群中有21个菌属,乌苏里貉粪便菌群中有21个菌属,豺粪便菌群中有19个菌属,还有一些未能鉴定的菌属。通过对五种犬科动物粪便菌群组成及多样性分析,发现粪便菌群组成在犬科动物之间不但具有物种特有性,还具有个体差异性。菌群总量在1010cfu/ml～1011cfu/ml之间,具有一定的稳定性,其中狼粪便菌群总量为(1.442±0.219)×1011cfu/g,赤狐粪便菌群总量为(0.833±0.097)×1011cfu/g,沙狐粪便菌群总量为(0.817±0.130)×1011cfu/g,乌苏里貉粪便菌群总量为(0.862±0.128)×1011cfu/g,豺粪便菌群总量为(1.485±0.144)×1011cfu/g。粪便菌群总量在同一物种不同个体间无明显差异(P>0.05),其中P(Canis lupus)=0.191;P(Vulpes vulpes)=0.898;P(Vulpes corsac)=0.315;P(Nyctereutes procyonoides)=0.074;P(Cuon alpinus)=0.197),不同物种间存在一定差异(P<0.05)。其中狼和豺粪便菌群总量无明显差异,赤狐、沙狐和乌苏里貉粪便菌群总量无明显差异,而狼和豺与赤狐、沙狐和乌苏里貉粪便菌群总量之间存在较为明显的差异(P<0.05)。粪便菌群组成在不同犬科动物间匹配度较高,大约在65%-80%之间,其中狼与赤狐、沙狐、乌苏里貉和豺的粪便菌群匹配度分别为66.67%、69.77%、69.77%、63.41%；赤狐与沙狐、乌苏里貉和豺的粪便菌群组成匹配度分别为80.00%、65.00%、78.95%；沙狐与乌苏里貉和豺的粪便菌群组成匹配度分别为71.43%和75.00%；乌苏里貉与豺的粪便菌群组成匹配度为70.00%。优势菌群主要包括埃希氏大肠杆菌、肠杆菌、链球菌、变形菌、肠球菌和乳酸杆菌,其中埃希氏大肠杆菌和肠杆菌为犬科动物共有优势菌,优势菌在不同犬科动物粪便菌群中有一定的差异,但相似度较高。更多还原

【Abstract】 Canidae, as the most widely distributed taxa in Carnivora, is inextricably linked to our life. Among the studies on canine animals, the researches of digestive physiology play a very important role, and the study on the digestive tract microbial communities is becoming a much hotter topic in recent years. Although the microbial communities in the different segments of the intestinal tract of domestic dogs (Canis lupus familiaris) have been good characterized in domestic and foreign, to our knowledge, no traditional culture-dependent methods has assessed the composition and diversity of the microbial communities in the intestinal tracts of wild carnivore species(Canis lupus, Vulpes vulpes, Vulpes corsac, Nyctereutes procyonoides, Cuon alpinus). Therefore, the first purpose of the present study is to characterize the microbial composition and diversity in the distal gut of a group of five healthy unrelated adult animals by using traditional culture-dependent methods. Comparative with the flora of intestinal in dogs have been reported, the conclusion reveals that the composition and diversity, community structure and microecological balance of the fecal flora of five carnivore species. The results have accumulated basic data for research the flora of intestinal in carnivore, and provided scientific basis for research microecology environment and disease in intestinal tract of carnivores.Gram-positive spore bacilli, gram-positive having no spore bacilli, gram-positive coccobacteria, gram-negative coccobacteria and gram-negative bacilli were first identified through microscopic observation and then formal identification tests were carried out, including oxygen needing, methyl red and Acetyl methyl methanol test, catalase, gelatin liquefaction, KNO3 reduction, indole, fermentation of saccharides and mellows, sodium citrate and NaCl-phily and so on. Based on the results of these physiological and biochemical tests, along with the morphological description, species from approximately 19-21 genera were identified in the feces. The number of genera in the feces was 22 in Canis lupus,19 in Cuon alpinus,21 in Nyctereutes procyonoides,21 in Vulpes corsac and 19 in Vulpes vulpes, as well as some unidentified strains.Although, some strains were endemic to the carnivore gut, there were some differences in the community among individuals and species. The carnivore fecal flora comprised 1010-1011 colony forming units/g of feces (wet weight). The amount of bacteria reached 1.442×1011cfu/g in Canis lupus,8.330×1010cfu/g in Vulpes vulpes,8.170×1010cfu/g in Vulpes corsac,8.620×1010cfu/g in Nyctereutes procyonoides and 1.485×1011cfu/g in Cuon alpinus. The amount of bacteria was significantly different among species (P<0.05) but not among different individuals of the same species (Canis lupus:P=0.19; Vulpes vulpes:P=0.898; Vulpes corsac:P=0.315; Nyctereutes procyonoides:P=0.074; Cuon alpinus:P=0.197). It is no obvious difference in the amount of bacteria between Canis lupus and Cuon alpinus, between Vulpes vulpes, Vulpes corsac and Nyctereutes procyonoides, but it has obvious differences between Canis lupus, Cuon alpinus and Vulpes vulpes, Vulpes corsac, Nyctereutes procyonoides.The percentage of shared species among different carnivores was 65-80%, with the highest percentage between Vulpes vulpes and Vulpes corsac, and the lowest between Canis lupus and Cuon alpinus. Although the proportion of shared species between Vulpes vulpes and Cuon alpinus was 78.95%, the amount of bacteria was markedly different. There was no correlation between the amount and the diversity of bacteria. The most common microbes were Escherichia, Enterobacter, Streptococcus, Proteus, Enterococcus and Lactobacillus. Of these, Escherichia and Enterobacter can be considered as beneficial strains and they were found in all the carnivores. Our findings suggest that, despite some differences, there is high similarity in the dominant fecal bacteria of different carnivores.更多还原