城市化梯度下入侵生物非洲大蜗牛肠道微生物群落特征

Characteristics of gut microbiome communities in the invasive African giant snail under urbanization gradient

为了探究城市化梯度下入侵物种非洲大蜗牛肠道微生物多样性及群落结构特征,本研究在厦门市城市、城郊及农村的5个公园中采集了30只非洲大蜗牛样本。利用三代PacBio测序平台对其16S rRNA基因进行全长测序,解析了非洲大蜗牛肠道及栖息地土壤微生物的群落特征。结果表明:非洲大蜗牛肠道微生物与栖息地土壤微生物群落的组成之间存在显著差异,且非洲大蜗牛肠道微生物对城市化的响应更为敏感。非洲大蜗牛的栖息地土壤微生物α多样性指数(Sobs、Chao、Shannon指数)均高于其肠道内。虽然城市、城郊和农村土壤微生物群落β多样性指数相似,但非洲大蜗牛肠道微生物群落组成存在显著差异。城市化显著影响了非洲大蜗牛肠道微生物群落的组成,在城市及城郊,非洲大蜗牛的肠道微生物主要为肠杆菌科、黄单胞菌科、支原体科,而在农村主要为链球菌科和类芽孢杆菌科。在城市环境中,非洲大蜗牛肠道微生物组中潜在人类致病菌的种类和丰度显著增加,意味着城市化增加了非洲大蜗牛传播潜在致病菌的风险。

To investigate the diversity and community structure of gut microbiome of the invasive species,Achatina fulica,along an urbanization gradient,we collected 30 A.fulica samples from five parks in the urban,suburban,and rural areas of Xiamen City.Using full-length 16S rRNA gene sequencing performed by the third generation PacBio sequencing platform,we analyzed the community characteristics of gut microbiome and soil microbiome in different habitats.We found a significant disparity between the composition of gut microbiome of A.fulica and that of the soil microbiome in their habitats.Furthermore,the gut microbiome of A.fulica were more sensitive to urbanization.The microbialα-diversity indices(Sobs,Chao,Shannon indices)in the soil of A.fulica habitats were consistently higher than those within their guts.Despite the similarβ-diversity indices of microbial communities in urban,suburban,and rural soils,we found a significant discrepancy in gut microbiome composition.Urbanization significantly influenced A.fulica gut microbiome composition.Gut microbiome of A.fulica in urban and suburban regions primarily consisted of Enterobacteriaceae,Xanthomonadaceae,and Mycoplasmataceae,while that in rural areas chiefly composed of Streptococcaceae and Paenibacillaceae.The diversity and abundance of potential human pathogenic bacteria within the gut microbiome of A.fulica significantly increased in urban environments,suggesting that urbanization escalated the risk of A.fulica transmitting potential pathogens.