Background:Biomphalaria straminea is an invasive vector in China,posing a significant threat to public health.Understanding the factors affecting the establishment of this snail is crucial to improve our ability to ma...Background:Biomphalaria straminea is an invasive vector in China,posing a significant threat to public health.Understanding the factors affecting the establishment of this snail is crucial to improve our ability to manage its dispersal and potential risk of schistosomiasis transmission.This study sought to determine the spatial distribution of B.straminea in China's Mainland and whether environmental factors were divergent between places with and without B.straminea.Methods:A malacological survey of B.straminea was conducted in Guangdong Province,China.Snails were identified using anatomical keys.Water and sediment samples were taken,and their physicochemical properties were analyzed using national standard methods.Landscape and climatic variables were also collected for each site.We compared the environmental characteristics between sites with and without B.straminea using Mann-Whitney U test.We further used generalized linear mixed models to account for seasonal effects.Results:B.straminea was found at six sites,including one in Dongguan and five in Shenzhen.Probability map found a hot spot of B.straminea distribution at Shenzhen and Hong Kong.Sites occupied by B.straminea were characterized by higher median altitude,mean annual precipitation and moderate temperature.Water with snails had higher median concentrations of total nitrogen,nitrate and nitrites,ammoniacal nitrogen,calcium,zinc and manganese but lower dissolved oxygen and magnesium.Sediments with snails had higher median copper,zinc and manganese.B.straminea was associated with maximum temperature of the warmest month(pMCMC<0.001)and sediment zinc(pMCMC<0.001).Conclusions:B.straminea is distributed in Shenzhen and its surrounding areas in Guangdong,China.Sites with and without B.straminea differed in the maximum temperature of the warmest month and sediment zinc.Surveillance should be continued to monitor the dispersal of this snail in China.展开更多
Background:Schistosomiasis is a common parasitic disease designated as a neglected tropical disease by the World Health Organization.Schistosomiasis mansoni is a form of the disease that is caused by the digenean trem...Background:Schistosomiasis is a common parasitic disease designated as a neglected tropical disease by the World Health Organization.Schistosomiasis mansoni is a form of the disease that is caused by the digenean trematode Schistosoma mansoni,transmitted through Biomphalaria spp.as an intermediate host.Biomphalaria was introduced to Hong Kong,China in aquatic plants shipments coming from Brazil and the snail rapidly established its habitats in southern China.Earlier studies of Biomphalaria spp.introduced to southern China identified the snails as Biomphalaria straminea,one of the susceptible species implicated in S.mansoni transmission in South America.However,recent molecular investigations also indicated the presence of another South American species,B.kuhniana,which is refractory to infection.As such,it is important to identify accurately the species currently distributed in southern China,especially with emerging reports of active S.mansoni infections in Chinese workers returning from Africa.Methods:We combined morphological and molecular taxonomy tools to precisely identify Biomphalaria spp.distributed in Guangdong Province,southern China.In order to clearly understand the molecular profile of the species,we constructed a phylogeny using mtDNA data(COI and 16S rRNA sequences)from six populations of Biomphalaria spp.from Shenzhen City in Guangdong Province.In addition,we examined the external morphology of the shell and internal anatomy of the reproductive organs.Results:Both morphological and molecular evidences indicated a close affinity between Biomphalaria spp.populations from Guangdong and B.straminea from Brazil.The shell morphology was roughly identical in all the populations collected with rounded whorls on one side and subangulated on the other,a smooth periphery,an egg-shaped aperture bowed to one side,and a deep umbilicus.The shape and number of prostate diverticula(ranged from 11.67 to 17.67)in Guangdong populations supports its close affinity to B.straminea rather than B.kuhniana.Molecular analysis did not conflict with morphological analysis.Little genetic differentiation was observed within Biomphalaria populations collected.Phylogenetic analysis of COI and 16S rRNA haplotypes from snails collected and B.straminea sequences from Brazil and China using Bayesian inference revealed that Guangdong populations were clustered in one clade with B.straminea from Hong Kong of China and B.straminea from Brazil indicating their close affinity to each other.Conclusions:Data obtained in the current study clearly show that the populations of Biomphalaria spp.investigated are B.straminea,and we assume that those snails were either introduced via passive dispersal from Hong Kong of China or as a result of multiple introduction routes from Brazil.展开更多
目的了解我国藁杆双脐螺来源,为我国曼氏血吸虫病流行风险评估和双脐螺控制提供依据。方法选择我国深圳市观澜河,大沙河,深圳水库,葵涌河上、下游,新圳河作为采样点,每个采样点采集10个双脐螺样本,提取螺样本基因组DNA。自南美洲巴西米...目的了解我国藁杆双脐螺来源,为我国曼氏血吸虫病流行风险评估和双脐螺控制提供依据。方法选择我国深圳市观澜河,大沙河,深圳水库,葵涌河上、下游,新圳河作为采样点,每个采样点采集10个双脐螺样本,提取螺样本基因组DNA。自南美洲巴西米纳斯吉拉斯州、帕拉州、联邦区、伯南布哥州、圣保罗州的5个采样点获得15个藁杆双脐螺DNA样本。对上述DNA样本的细胞色素c氧化酶亚基Ⅰ(cytochrome c oxidaseⅠ,COI)和线粒体16S核糖体RNA(16S ribosomal RNA,16S rRNA)基因进行扩增和测序。同时,从GenBank中下载藁杆双脐螺COI和16S rRNA基因序列,并获取其采样点信息。将所有基因序列进行比对并构建进化树,分析我国和南美洲双脐螺样本的遗传相似度和谱系进化关系。结果从我国双脐螺样本中共获得60个长度为529 bp的COI序列,其中3个为单倍型。从GenBank中获得165条藁杆双脐螺COI序列,与上述60条序列比对后,共获得33个单倍型。进化树分析显示,采自我国的双脐螺3个单倍型聚在一支,其中单倍型China11与GenBank中获得的来自巴西的3个样本属于同一单倍型。地理进化分析结果显示,巴西东部沿海3个采样点的样本有与我国China11相同的单倍型,另2个采样点的样本与China11亲缘关系较近。扩增我国双脐螺样本16S r DNA基因,共获得60条长度约为322 bp的序列和2个单倍型。从GenBank中获得70条藁杆双脐螺16S rDNA序列。系统进化树分析显示,我国双脐螺样本聚为一支,其中单倍型China64与来自巴西的229BS为同一单倍型。将GenBank中获取的来自巴西南部25个采样点的49个藁杆双脐螺16S r DNA序列纳入分析,发现其中3个采样点的藁杆双脐螺与我国China64有相同的单倍型。综合分析藁杆双脐螺COI和16S rRNA的地理系统进化关系,发现仅巴西东部沿海地带样本与我国双脐螺样本在两个基因片段序列上具有相同单倍型。结论我国双脐螺为藁杆双脐螺,遗传多样性较低,与来自巴西东部沿海地区的样本遗传学相似度很高,可能来源于巴西东部沿海地区。展开更多
基金This work was supported by the National Research and Development Plan of China(No.2016YFC1200500).
文摘Background:Biomphalaria straminea is an invasive vector in China,posing a significant threat to public health.Understanding the factors affecting the establishment of this snail is crucial to improve our ability to manage its dispersal and potential risk of schistosomiasis transmission.This study sought to determine the spatial distribution of B.straminea in China's Mainland and whether environmental factors were divergent between places with and without B.straminea.Methods:A malacological survey of B.straminea was conducted in Guangdong Province,China.Snails were identified using anatomical keys.Water and sediment samples were taken,and their physicochemical properties were analyzed using national standard methods.Landscape and climatic variables were also collected for each site.We compared the environmental characteristics between sites with and without B.straminea using Mann-Whitney U test.We further used generalized linear mixed models to account for seasonal effects.Results:B.straminea was found at six sites,including one in Dongguan and five in Shenzhen.Probability map found a hot spot of B.straminea distribution at Shenzhen and Hong Kong.Sites occupied by B.straminea were characterized by higher median altitude,mean annual precipitation and moderate temperature.Water with snails had higher median concentrations of total nitrogen,nitrate and nitrites,ammoniacal nitrogen,calcium,zinc and manganese but lower dissolved oxygen and magnesium.Sediments with snails had higher median copper,zinc and manganese.B.straminea was associated with maximum temperature of the warmest month(pMCMC<0.001)and sediment zinc(pMCMC<0.001).Conclusions:B.straminea is distributed in Shenzhen and its surrounding areas in Guangdong,China.Sites with and without B.straminea differed in the maximum temperature of the warmest month and sediment zinc.Surveillance should be continued to monitor the dispersal of this snail in China.
基金This work was supported by the National Key Research and Development Program of China(No.2016YFC1202001)Research Fund for the Technical Reserves,National Institute of Parasitic Diseases,Chinese CDC(No.CB-1603)+1 种基金Mohamed R.Habib was supported by a Post-doctoral Programme from the Ministry of Science and Technology of China and National Center for International Research on Tropical Diseases(Shanghai,China)Roberta L.Caldeira is supported by a fellowship from Conselho Nacional de Desenvolvimento Científico e Tecnologico/CNPq(No.304121/2014–2).
文摘Background:Schistosomiasis is a common parasitic disease designated as a neglected tropical disease by the World Health Organization.Schistosomiasis mansoni is a form of the disease that is caused by the digenean trematode Schistosoma mansoni,transmitted through Biomphalaria spp.as an intermediate host.Biomphalaria was introduced to Hong Kong,China in aquatic plants shipments coming from Brazil and the snail rapidly established its habitats in southern China.Earlier studies of Biomphalaria spp.introduced to southern China identified the snails as Biomphalaria straminea,one of the susceptible species implicated in S.mansoni transmission in South America.However,recent molecular investigations also indicated the presence of another South American species,B.kuhniana,which is refractory to infection.As such,it is important to identify accurately the species currently distributed in southern China,especially with emerging reports of active S.mansoni infections in Chinese workers returning from Africa.Methods:We combined morphological and molecular taxonomy tools to precisely identify Biomphalaria spp.distributed in Guangdong Province,southern China.In order to clearly understand the molecular profile of the species,we constructed a phylogeny using mtDNA data(COI and 16S rRNA sequences)from six populations of Biomphalaria spp.from Shenzhen City in Guangdong Province.In addition,we examined the external morphology of the shell and internal anatomy of the reproductive organs.Results:Both morphological and molecular evidences indicated a close affinity between Biomphalaria spp.populations from Guangdong and B.straminea from Brazil.The shell morphology was roughly identical in all the populations collected with rounded whorls on one side and subangulated on the other,a smooth periphery,an egg-shaped aperture bowed to one side,and a deep umbilicus.The shape and number of prostate diverticula(ranged from 11.67 to 17.67)in Guangdong populations supports its close affinity to B.straminea rather than B.kuhniana.Molecular analysis did not conflict with morphological analysis.Little genetic differentiation was observed within Biomphalaria populations collected.Phylogenetic analysis of COI and 16S rRNA haplotypes from snails collected and B.straminea sequences from Brazil and China using Bayesian inference revealed that Guangdong populations were clustered in one clade with B.straminea from Hong Kong of China and B.straminea from Brazil indicating their close affinity to each other.Conclusions:Data obtained in the current study clearly show that the populations of Biomphalaria spp.investigated are B.straminea,and we assume that those snails were either introduced via passive dispersal from Hong Kong of China or as a result of multiple introduction routes from Brazil.
文摘目的观察新型灭螺剂10%氯代水杨胺制剂(chlorosalicylicamide,LDS)对曼氏血吸虫(Schistosoma mansoni)中间宿主光滑双脐螺(Biomphalaria glabrata)和藁杆双脐螺(Biomphalaria straminea)的作用效果,为该灭螺剂的现场应用提供实验基础。方法将10%LDS配制成有效浓度分别为0.4000、0.2000、0.1000、0.0500、0.0250、0.0125 mg/L的系列标准溶液,在实验室浸泡光滑双脐螺和藁杆双脐螺,观察在不同浓度溶液中浸杀上述2种双脐螺24、48、72 h后螺的死亡情况,统计各组死亡率并计算半数致死浓度(LC_(50))和相对毒力指数,同时设立50%氯硝柳胺乙醇胺盐(50%wet‐table power of niclosamide ethanolamine salt,WPN)为药物对照组,并设立空白对照组(去氯水)。结果LDS有效浓度在0.1000 mg/L及以上时,WPN有效浓度在0.2000 mg/L及以上时光滑双脐螺和藁杆双脐螺浸泡24、48、72 h后死亡率均能达到100%。光滑双脐螺浸泡在LDS系列浓度溶液中,24、48、72 h LC_(50)分别为0.04795、0.04652、0.03710 mg/L;光滑双脐螺浸泡在WPN系列浓度溶液中,24、48、72 h LC_(50)分别为0.06348、0.05705、0.05705 mg/L。藁杆双脐螺浸泡在LDS系列浓度溶液中,24、48、72 h LC_(50)分别为0.01235、0.01399、0.00840 mg/L;藁杆双脐螺浸泡在WPN系列浓度溶液中,24、48、72 h LC_(50)分别为0.05895、0.02571、0.02375 mg/L。以LC_(50)值较大的WPN为标准药物,其相对毒力指数为1.00,LDS对光滑双脐螺浸杀24、48、72 h后的相对毒力指数分别为1.32、1.23、1.54;LDS对藁杆双脐螺浸杀24、48、72 h后的相对毒力指数分别为4.77、1.84、2.83。使用LDS浸杀上述2种双脐螺24、48、72 h后,光滑双脐螺存活数均高于藁杆双脐螺,差异有统计学意义(χ^(2)=8.044、5.263、4.658,P<0.05)。结论相较于传统灭螺药物WPN,10%LDS对光滑双脐螺和藁杆双脐螺杀灭效果更佳,尤其对藁杆双脐螺作用效果更为敏感,具有替代作用。
文摘目的了解我国藁杆双脐螺来源,为我国曼氏血吸虫病流行风险评估和双脐螺控制提供依据。方法选择我国深圳市观澜河,大沙河,深圳水库,葵涌河上、下游,新圳河作为采样点,每个采样点采集10个双脐螺样本,提取螺样本基因组DNA。自南美洲巴西米纳斯吉拉斯州、帕拉州、联邦区、伯南布哥州、圣保罗州的5个采样点获得15个藁杆双脐螺DNA样本。对上述DNA样本的细胞色素c氧化酶亚基Ⅰ(cytochrome c oxidaseⅠ,COI)和线粒体16S核糖体RNA(16S ribosomal RNA,16S rRNA)基因进行扩增和测序。同时,从GenBank中下载藁杆双脐螺COI和16S rRNA基因序列,并获取其采样点信息。将所有基因序列进行比对并构建进化树,分析我国和南美洲双脐螺样本的遗传相似度和谱系进化关系。结果从我国双脐螺样本中共获得60个长度为529 bp的COI序列,其中3个为单倍型。从GenBank中获得165条藁杆双脐螺COI序列,与上述60条序列比对后,共获得33个单倍型。进化树分析显示,采自我国的双脐螺3个单倍型聚在一支,其中单倍型China11与GenBank中获得的来自巴西的3个样本属于同一单倍型。地理进化分析结果显示,巴西东部沿海3个采样点的样本有与我国China11相同的单倍型,另2个采样点的样本与China11亲缘关系较近。扩增我国双脐螺样本16S r DNA基因,共获得60条长度约为322 bp的序列和2个单倍型。从GenBank中获得70条藁杆双脐螺16S rDNA序列。系统进化树分析显示,我国双脐螺样本聚为一支,其中单倍型China64与来自巴西的229BS为同一单倍型。将GenBank中获取的来自巴西南部25个采样点的49个藁杆双脐螺16S r DNA序列纳入分析,发现其中3个采样点的藁杆双脐螺与我国China64有相同的单倍型。综合分析藁杆双脐螺COI和16S rRNA的地理系统进化关系,发现仅巴西东部沿海地带样本与我国双脐螺样本在两个基因片段序列上具有相同单倍型。结论我国双脐螺为藁杆双脐螺,遗传多样性较低,与来自巴西东部沿海地区的样本遗传学相似度很高,可能来源于巴西东部沿海地区。
