吸血行为对草原革蜱和森林革蜱中肠菌群结构的影响

Effects of Blood-sucking Behavior on the Microbial Community in the Midgut of Dermacentor nuttalli and Dermacentor silvarum

本研究旨在探明随吸血时间的延长,草原革蜱和森林革蜱中肠菌群结构的特征及变化。从内蒙古呼伦贝尔和宁夏固原绵羊体表分别采集半饱血、饱血草原革蜱和半饱血、饱血森林革蜱,无菌条件下收集蜱中肠内容物,提取细菌总DNA,扩增细菌16S rDNA V3-V4区,IonS5^TMXL高通量测序,对比分析各样本菌群结构的特征。结果显示,森林革蜱半饱血中肠内的细菌多样性最高,草原革蜱饱血和半饱血中肠内的细菌多样性次之,森林革蜱饱血中肠内的细菌多样性最低;变形菌门为4个样品的优势菌门;无形体属、立克次体属、寡养单胞菌属和柯克斯体属为4个样品的优势菌属,其中无形体属在草原革蜱和森林革蜱饱血中肠内的含量高于2种蜱半饱血中肠,立克次体属和柯克斯体属在2种蜱半饱血中肠内的含量明显大于饱血中肠;边缘无形体、弯曲假单胞菌和柯克斯体科RFE02菌为4个样品的优势菌种,其中边缘无形体的分布特点与无形体属在2种蜱中肠内的分布特点相一致。结果表明,草原革蜱和森林革蜱中肠菌群结构易受到吸血行为的影响,共有菌属和菌种在不同蜱种和不同饱血状态下的相对丰度变化较大。

The aim of this study is to investigate the characteristics and changes of bacterial flora in midguts of Dermacentor nuttalli and Dermacentor silvarum with the extension of feeding time.The half or fully engorged D.nuttalli and D.silvarum were obtained from sheep body surface in Hulun Buir of Inner Mongolia and Guyuan of Ningxia,respectively.The midgut contents were collected from ticks under sterile environment.Then the total DNA of bacteria were extracted and the V3-V4 areas of 16 S rDNA were amplified.The PCR product of each sample was sequenced by IonS5^TMXL high-throughput sequencing platform.Each sample’s bacterial flora characteristic and the differences among four groups(half engorged D.nuttalli,fully engorged D.nuttalli,half engorged D.silvarum and fully engorged D.silvarum)were analyzed.The results showed that the bacterial diversity of midguts from the half engorged D.silvarum was the highest,followed by that of midguts from half and fully engorged D.nuttalli,the bacterial diversity of midguts from the fully engorged D.silvarum was the lowest.Proteobacteria was the most predominant phyla in all samples.Anaplasma,Rickettsia,Stenotrophomonas and Coxiella were the major genera.The relative abundance of Anaplasma in midguts from fully engorged D.nuttalli and D.silvarum were higher than that in the midguts from the half engorged ticks.The relative abundance of Rickettsia and Coxiella in midguts from half engorged D.nuttalli and D.silvarum were higher than that in the midguts from the fully engorged ticks.Anaplasma marginale,Pseudomonas geniculate and Coxiellaceae bacterium RFE02 were the most predominant species in four samples.Distributions of A.marginale in the midguts of D.nuttalli and D.silvarum were consistent with that of Anaplasma.These findings suggested that the midgut bacterial flora of D.nuttalli and D.silvarum are susceptible to the blood-sucking behavior.The relative abundance of common bacteria genera and species vary greatly in different tick species and engorged statuses.