ABSTRACT
Angiostrongylus cantonensis is a food-borne zoonotic parasite, and human infection may cause eosinophilic meningitis. Non-coding RNAs (ncRNAs) may regulate physiological and pathological processes at multiple biological levels; however, there are few studies pertaining to the regulatory role of ncRNAs in A. cantonensis infection. Based on publications retrieved from PubMed, Wanfang Data and CNKI, the regulatory role of ncRNAs in A. cantonensis infections mainly includes immune responses, cell apoptosis and signaling transduction, and ncRNAs may serve as biomarkers for diagnosis of angiostrongyliasis. This review summarizes the main roles of ncRNAs in A. cantonensis infections and the underlying mechanisms, so as to provide insights into diagnosis and treatment of angiostrongyliasis.
ABSTRACT
Objective:To study the population distribution of Pomacea spp. in Shandong Province and the risk of angiostrongyliasis cantonensis in the local population, and to provide a basis for scientific prevention and control of related diseases. Methods:From July to December 2021, Yanzhou District of Jining City, Ningyang County of Taian City, and Dongying District of Dongying City were selected as surveillance sites to investigate the population and distribution range of Pomacea spp., live snail samples were collected for morphological and genetic identification, and Pomacea spp. infected with the larva of Angiostrongylus cantonensis was detected by lung test. At the same time, sentinel hospital case surveillance was carried out in Yanzhou District, Jining City, and questionnaire was used to study the local residents' awareness of angiostrongyliasis cantonensis and their personal health behaviors. Results:A total of 312 live snail samples were collected. After morphological identification, they were all Pomacea spp.. After gene sequencing, two populations of Pomacea canaliculata and Pomacea maculata were found. No positive snails infected with Angiostrongylus cantonensis were found. A total of 126 patients with headache as the main neurological symptom were admitted to the sentinel hospital, but there were no monitoring cases that met the inclusion criteria. Among the survey population, 48.38% (134/277) of the respondents had heard of angiostrongyliasis cantonensis, 44.77% (124/277) knew that eating Margarya melanioides might cause angiostrongyliasis cantonensis, and 83.39% (231/277) had no related unhealthy eating behavior. Conclusion:Pomacea spp. is found and reported for the first time in Shandong Province, and there is a risk of population infection with angiostrongyliasis cantonensis.
ABSTRACT
Angiostrongyliasis cantonensis is an emerging infectious disease in China. Snails are intermediate hosts of Angiostrongylus cantonensis and play a critical role in the transmission of angiostrongyliasis cantonensis. Detection of A. cantonensis in snails is an important part of epidemiological surveys. Currently, the rapid developments in the techniques for detection of A. cantonensis in snails facilitate the surveillance of angiostrongyliasis cantonensis and provide an important support for angiostrongyliasis cantonensis prevention and control. This review summarizes the advances in the techniques for detection of A. cantonensis in snails.
ABSTRACT
Objective To study the dynamic diffusion characteristics of Biomphalaria straminea in Shenzhen, Dongguan and Huizhou of Southern China. Methods B. straminea was monitored at 25 investigation points along 10 river channels in Shenzhen, Dongguan and Huizhou by salvaging method. The diffusion characteristics of snails along with water in the Guihua New Village section of the Guanlan River and the Dawei Village section of the Longgang River were analyzed by GPS location drift test. In addition, the influence of flooding on the diffusion of B. straminea in the Kuichong River both before and after Typhoon "Shanzhu" was analyzed by monitoring the hydrology and distribution of snails. Results In March and October from 2016 to 2018, a total of 1 176 kg of floating objects were salvaged in rivers in Shenzhen, Dongguan and Huizhou. Scattered B. straminea were found on water hyacinths. Drift test of floats with GPS showed that the average drift speed of GPS floating objects was close to the river surface velocity. Affected by river current and wind direction, the GPS floats quickly drifted to the river bank and stopped in the stagnant area due to the blockade of water plants, stone and the bending of the shoreline. The drift distance of each time was between 136 - 715m. The test results of salvaged floating objects found that the loss rates of B. straminea were 46.70% - 60.00% and 22.10% - 30.80%, in the Guihua New Village section of the Guanlan River and the Dawei Village section of the Longgang River, respectively, which were significantly affected by the floating weight, river velocity and drifting distance. The analysis of the hydrology and distribution of B. straminea in the Kuichong River both before and after Typhoon "Shanzhu" showed that the density of B. straminea in the river was significantly reduced by the flood. Conclusion B. straminea is mainly transported as suspended matter in water body, and flooding was an important factor in its long-distance diffusion.
ABSTRACT
Objective To distinguish two Bithynia species,Bithynia fuchsiana and Bithynia robusta collected from Heng County,Guangxi Zhuang Autonomous Region,by using morphological and DNA barcoding methods. Methods The adult B. fuchsiana and B. robusta were collected from the biotope such as rivers,ditches and ponds in Heng County of Guangxi Zhuang Autonomous Region,China. The two species specimens were identified by measuring shell morphological parameters,compar?ing the characters of the male reproductive system,and using the COI gene barcoding technique and building phylogenetic tree. Results B. fuchsiana and B. robusta were similar morphologically in the shell appearance;they had the similar snail height, snail width,shape and male reproductive structure. The DNA sequence analysis showed that the COI gene of the two Bithynia species had low sequence divergence with 11 variation sites among 22 sequences. The length of the COI gene segment was 517 bp and no insertion sites and deletion loci after sequence edited. All individuals of the two species gathered to one clade in the phylogenetic tree based on COI gene. Conclusion According to the evidence of morphology and COI gene coding sequence,B. fuchsiana and B. robusta from Heng County,Guangxi Zhuang Autonomous Region,are likely to be the same species.
ABSTRACT
Objective To investigate the species diversity and distribution of medical mollusca in Shanghai City. Methods From August 2012 to October 2013,all kinds of habitats in 8 districts and counties in Shanghai City,namely Jiading,Qingpu, Baoshan,Minhang,Songjiang,Jinshan,Chongming,Pudong,were selected for the field survey according to the distribution characteristics of the river system,and all the specimens of medical mollusca in the investigation sites were collected and classi?fied by morphological identification. Meanwhile,the species composition,habitats as well as the fauna of the medical mollusca collected were analyzed. Results A total of 5 211 specimens were collected,which belonged to 2 classes,14 families,18 gen?era and 25 species,including Oncomelania hupensis hupensis,Pomacea canaliculata,Parafossarulus striatulus,Alocinma longicornis,Physa acuta,Galba pervia,Hippeutis cantori,etc. The species numbers of medical mollusca in Chongming,Jin?shan,Pudong new area and Qingpu districts(counties)were 22,22,21 and 20,respectively,which were more than those of other areas. The habitat analysis suggested that the species numbers in the river and wetland were the most,both of which were 14 species. The main faunas of the medical mollusca in Shanghai were the cosmopolitan and oriental species. Conclusions The freshwater gastropod species are paucity in Shanghai City,but almost of them can be served as the intermediate hosts of certain parasites to transmit snail?related parasitic diseases,so the surveillance of medical mollusca should be strengthened.
ABSTRACT
Objective To identify the species classification of an ornamental Planorbidae from a flower market in Shanghai and analyze its potential distribution in China. Methods In August 2013,six freshwater snail specimens were collected from the Wanshang flower market. The species was identified by morphology and molecular biology. An ecological niche model was constructed based on the native geographic presence occurrence data,and projected onto the whole of China to predict the poten?tial distribution. Results Their shell external morphology suggested that the specimens belonged to Planorbella trivolvis(Say 1817)of Planorbidae,which is native in North America. The sequence data of a fragment of the mitochondrial cytochrome c oxi?dase subunit I(COI)confirmed its identification. A total of 2 294 georeferenced occurrence points in North America were car?ried out from the Global Biodiversity Information Facility databases and 614 records with coordinates were used to produce a North American native niche model by a maximum entropy method(Maxent). The projection on China results suggested high probabilities of occurrence mostly in Henan Province and its borderland with nearby provinces. Conclusions P. trivolvis is sim?ilarly with Biomphalaria species from shell morphology. It is the first records of the species in China,and the field dispersal is not clear.
ABSTRACT
Objective To compare the diversity of mitochondrial genomes of Angiostrongylus cantonensis in the mainland of China. Methods According to the population genetic of A. cantonensis,seven female worms were selected to characterize the mi-tochondrial(MT)genomes. Twelve primer pairs based on known MT genome(GQ398121)were used for PCR. The target frag-ments were sequenced and aligned. The gene localization,genome structure,composition of nucleotide,distribution of variable sites,and phylogeny were analyzed by employing multiple softwares. Results Five distinct types were identified from seven com-plete MT genomes. They were similar in size and structure,i.e.,ranging 13 491-13 502 bp,including 12 protein-coding genes,2 ribosomal genes,22 tRNA genes,and 2 major non-coding regions. All the genes were localized at the same strand and had the same transcription direction. A total of 745 variable sites were identified,accounting for 5.5%. Among the variable sites,59 were deletion/insert mutations,105 transversions,and 581 transitions. The variable sites distributed evenly at the complete genome. Conclusion The study reveals the mutation profile in the whole MT genome of A. cantonensis and thus will facilitate the develop-ment of intraspecific differential diagnosis.