Demyelinating diseases of the central nervous system are common,yet few effective strategies for myelin repair and remyelination are available.An increasing number of studies highlight the role of microRNAs(miRNAs)as ...Demyelinating diseases of the central nervous system are common,yet few effective strategies for myelin repair and remyelination are available.An increasing number of studies highlight the role of microRNAs(miRNAs)as key regulators of demyelination.miRNA mimics and inhibitors,which are currently in preclinical development,have shown promise as novel therapeutic agents.However,the mechanisms by which they protect myelin are not fully understood.Using a mouse model of acute central nervous system demyelination induced by infection with Angiostrongylus cantonensis,we investigated alterations in miRNA expression in the mouse brain.Our findings revealed a significant early-stage increase in the levels of miR-200,particularly miR-200a and miR-200c.Subsequent analysis demonstrated that combined miR-200a and miR-200c overexpression improved neurobehavioral outcomes and attenuated demyelination in Angiostrongylus cantonensis-infected mice.Further lipid metabolomic profiling indicated that miR-200a and miR-200c synergistically inhibited the production of phosphatase and tensin homolog(PTEN)and activated the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway,as confirmed by double luciferase reporter assay and western blotting.Additionally,in vitro experiments showed that miR-200a and miR-200c protected oligodendrocyte precursor cells from lipopolysaccharide-induced damage and enhanced their survival.Our study indicates the critical role of miR-200a and miR-200c in protecting against central nervous system demyelination by targeting PTEN and modulating key survival pathways.Furthermore,our findings suggest that miR-200a and miR-200c are promising diagnostic biomarkers of and therapeutic targets for treating demyelination-related disorders.展开更多
BACKGROUND Angiostrongylus cantonensis-induced acute parasitic infection is a rare food-borne disease in clinical practice.Lack of its specific laboratory markers and subsequent difficulty in detecting pathogens cause...BACKGROUND Angiostrongylus cantonensis-induced acute parasitic infection is a rare food-borne disease in clinical practice.Lack of its specific laboratory markers and subsequent difficulty in detecting pathogens cause high misdiagnosis and missed diagnosis rates.CASE SUMMARY A 20-year-old male developed persistent neck and back pain after consuming raw snail meat,followed by urinary retention and low fever.After admission,the patient was misdiagnosed as viral infection and Mycobacterium tuberculosis in central nervous system.After detection of Angiostrongylus cantonensis in blood and cerebrospinal fluid by metagenomics next generation sequencing,albendazole was administered with ceftriaxone and methylprednisolone treatment simultaneously.With effective antiparasitic treatment,the patient weaned from mechanical ventilation successfully and transferred out of intensive care unit for hyperbaric oxygen and rehabilitation treatment.CONCLUSION This case highlights the diagnostic challenges of Angiostrongylus cantonensis infection and the importance of advanced sequencing techniques in identifying rare pathogens.展开更多
研究了民间草药甜草O ldenlandia cantonensisHow的化学成分。从乙醇提取物的乙酸乙酯洗脱部分得到新的五环三萜urs-12-en-29-αoic ac id-3β-ol。该化合物结构通过NMR、IR、MS等波谱数据综合解析确定。研究了urs-12-en-29-αoic ac i...研究了民间草药甜草O ldenlandia cantonensisHow的化学成分。从乙醇提取物的乙酸乙酯洗脱部分得到新的五环三萜urs-12-en-29-αoic ac id-3β-ol。该化合物结构通过NMR、IR、MS等波谱数据综合解析确定。研究了urs-12-en-29-αoic ac id-3β-ol对重组人DNA拓扑异构酶Ⅰ、肝癌细胞BEL-7402和胃腺癌细胞MCG-803的抑制作用,效果显著,IC50值分别为12.0×10-6、6.5×10-6、8.0×10-6g/mL。由V(石油醚)∶V(乙酸乙酯)=20∶1洗脱得到的低极性成分进行了气相色谱-质谱分析,共鉴定60个化合物,其中长链脂肪族化合物,如烷烃、饱和及不饱和羧酸(酯)含量较丰富,占36.16%,萜类和甾体类化合物分别占6.42%和9.28%。展开更多
Objective:To understand the current epidemiological status of Angiostrongylus cantonensis in Hainan island and provide the scientific evidences for prevention and control of the disease.Methods:The investigation on na...Objective:To understand the current epidemiological status of Angiostrongylus cantonensis in Hainan island and provide the scientific evidences for prevention and control of the disease.Methods:The investigation on nature infection condition of intermediate hosts and final hosts of Angiostrongylus cantonensis were carried out in five counties,Hainan Province, and enzyme linked immunosorbent assay(ELISA) was employed to detect antibodies of Angiostrongylus cantonensis in human hosts.Results:A total of 1 612 molluscs were examined, 21.3%of which harbored L3 of Angiostrongylus cantonensis.Among them,the infection rates of Pomacea canaliculata,Achatina fulica,Cepaea and Phlegm bilineatus were 12.3696(64/518), 22.66%(121/534),20.93%(9/43),and 28.24%(146/517),respectively.Of the 118 rats trapped,13 Rattus norvegicus were found to be infected with Angiostrongylus cantonensis.A total of 459 serum samples were collected and tested.92 serum samples were Angiostrongylus cantonensis antibody-positive.Conclusions:The survey revealed a wide distribution of Angiostrongylus cantonensis in Hainan island.Pomacea canaUculata and Achatina fulica are main intermediate hosts of Angiostrongylus cantonensis.Rattus novegicus is a nature definitive host,indicating that a considerable number of people are at risk of angiostrongyliasis.Health education,rigorous food inspection and surveillance are all needed to prevent angiostrongyliasis outbreaks in future.展开更多
Objective:To survey the Angiostrongylus cantonensis(A.cantonensis) or the rat lungworm in a rat,definitive host,and in a giant African land snail(Achatina fulica),the intermediate host,in Phitsanulok,Thailand.Methods:...Objective:To survey the Angiostrongylus cantonensis(A.cantonensis) or the rat lungworm in a rat,definitive host,and in a giant African land snail(Achatina fulica),the intermediate host,in Phitsanulok,Thailand.Methods:Rats and giant African land snails were captured from Tha Pho sub-district,Phitsanulok,Thailand.Rats were killed and examined for adult A.cantonensis. The artificial digestion method following Baermann technique were used for isolation third stage larvae of A.cantonensis.Results:Sixty-two rats were captured and they were identified as Rattus argentiventer,Rattus rattus(R.rattus),Bandicota savilei,and Bandicota indica but only one animal(R.rattus) of 62 rats(1.61%) was positive with adult worm of A.cantonensis.The third stage larvae of A.cantonensis were examined on 307 Angiostrongylus fulica snails.It was found that the overall infection rate was 12.38%(38 infected out of 307 Achatina snails).Conclusions: This study demonstrates that A.cantonensis is available in the natural hosts of Phitsanulok.This suggests that the transmissions of this parasite to human may occur in this region.展开更多
[Objectives] This study was conducted to establish a characteristic fingerprinting research method for the chemical constituents of the Zhuang medicine Pholidota cantonensis Rolfe.and its characteristic fingerprint of...[Objectives] This study was conducted to establish a characteristic fingerprinting research method for the chemical constituents of the Zhuang medicine Pholidota cantonensis Rolfe.and its characteristic fingerprint of chemical constituents,in order to identify P.cantonensis.[Methods] Ten batches of P.cantonensis from different habitats in Guangxi and out of Guangxi (Shaoguan of Guangdong Province) were determined.The materials were extracted in 80% methanol ultrasonically for 1.5 h under the material-to-liquid ratio of 2.5 g/80 ml.The HPLC determination was carried out using an Agilent 1260 HPLP instrument equipped with an Agilent5 TC-C18 (2) column at the column temperature of 30 ℃,the wavelength of 280 nm and the injection volume of 10 μl using acetonitrile-0.4% phosphoric acid as the mobile phase and chlorogenic acid as the reference peak,and the detection took 58 min.[Results] The characteristic fingerprint of the chemical constituents of P.cantonensis were obtained,and the three chromatographic peaks of gallic acid,chlorogenic acid and syringaldehyde were compared.[Conclusions] This study can provide reference for the identification of the Zhuang medicine P.cantonensis and provide guarantee for the clinical use of Chinese medicine.展开更多
Research progress of pharmacognostical identification and chemical composition of Pholidota cantonensis Rolfe. was reviewed. This paper will facilitate assurance of the safety of clinical treatment.
Objectives:Fish are hypothesized to act as paratenic hosts for the zoonotic nematode Angiostrongylus cantonensis,which causes human eosinophilic meningitis.There is a lack of data confirming the relevance of fish in A...Objectives:Fish are hypothesized to act as paratenic hosts for the zoonotic nematode Angiostrongylus cantonensis,which causes human eosinophilic meningitis.There is a lack of data confirming the relevance of fish in A.cantonensis life cycle and their contribution to human infection.Materials and Methods:We conducted a series of experiments to investigate the survival and infectivity of A.cantonensis larvae in Clarias gariepinus(catfish;n=30)and Oreochromis niloticus(tilapia;n=24).Each fish was inoculated with 10000 third-stage larvae(L3).Larval survival was assessed through artificial digestion of fish tissues 1 week,2 weeks,and 3 weeks post-infection.To investigate the early stages of infection,four catfish were inoculated with 10000 L3 each and sacrificed 3 d post-infection.Quantitative polymerase chain reaction(qPCR)analysis and histopathological examination were performed to evaluate larval distribution and tissue reactions.Two infected catfish,sacrificed 1 week post-infection,were used to feed Wistar rats.Results:After 45 d,the rats did not shed first-stage larvae(L1),indicating the absence of infection.One week post-infection,dead larvae were present in the digested tissues of both fish species,and the same was observed 2 weeks and 3 weeks after exposure.qPCR analysis revealed that the intestine was the most heavily infected organ.Histopathological examination identified dead larvae within granulomas in both the intestines and liver.Early-stage infection experiment showed that fish sacrificed 3 d post-inoculation contained viable L3,which was infective to Wistar rats.Conclusions:While A.cantonensis L3 can survive and remain infective in fish for a short period,they typically die within first few days postinfection.This suggests that fish may not be significant long-term paratenic hosts for A.cantonensis but may play a temporary role in its transmission to mammals(including humans)and birds.These results are consistent with previous studies on freshwater shrimps and highlight the importance of understanding aquatic host interactions in the epidemiology of this zoonotic foodborne pathogen.展开更多
Background Angiostrongyliasis cantonensis is a worldwide-existing parasitic disease. However, the relevant reports on its radiological appearances are limited. In this study, we investigated magnetic resonance imaging...Background Angiostrongyliasis cantonensis is a worldwide-existing parasitic disease. However, the relevant reports on its radiological appearances are limited. In this study, we investigated magnetic resonance imaging （MRI） features of eosinophilic meningoencephalitis in a group of consecutive patients caused by human infection with Angiostrongylus cantonensis after eating freshwater snails. Methods We performed brain MR imaging on 74 patients with angiostrongyliasis cantonensis. The scanner was a 0.5T unit. For each patient MR pulse sequences of $E Tl-weighted image （TlWl） and FSE T2-weighted image （T2Wl） were used. After intravenous administration of gadolinium chelate （Gd-DTPA） repeated Tl-weighted images were obtained. MRI features of the lesions in the brain and meninges were analyzed and recorded after observing initial and follow-up MR images. The classification of the types of angiostrongyliasis cantonensis infection was done on the basis of locations of the disorders. Results Forty-one （55%） normal and 33 （45%） abnormal MRI appearances in the brain were found. According to locations of the disorders, the types of angiostrongyliasis cantonensis infection were determined as follows： seventeen cases of type meningitis, three of type myeloencephalitis, one of type neuritis and twelve of mixed type （eight of type ventriculitis and five of type pneumonitis were among them）. In type meningitis, abnormal leptomeningeal enhancement was visualized. In type myeloencephalitis, lesions in the brain parenchyma may have iso- or slightly low signal intensity on TlWl and high signal intensity on T2Wl. Enhanced nodules in various shapes were shown on gadolinium-enhanced TlWl, a few lesions appeared as crescent enhancements and some lesions did not reveal abnormal enhancement. Other than brain lesions, an enhanced nodule was seen in the cervical spinal cord in one patient. In type ventriculitis, brain ventricular enlargement was demonstrated. In type neuritis, a nodule and abnormal enhancement in the right optic nerve was revealed. In type pneumonitis, patchy ground-glass opacity and consolidative lesions at the periphery of the lungs were seen. Follow-up results indicated that most lesions in the brain could resolve in 2 to 8 weeks. Conclusions Angiostrongyliasis cantonensis presented as both single type and mixed type. Nodular enhancing lesions in the brain and/or linear enhancement in the leptomeninges were the main findings, while crescent enhancement would be the characteristic sign of the disease on gadolinium-enhanced TlWI. Focal edematous changes without contrast enhancement in the brain could be seen on MRI in some cases.展开更多
Background:Angiostrongyliasis is a food-borne parasitic zoonosis.Human infection is caused by infection with the third-stage larvae of Angiostrongylus cantonensis.The life cycle of A.cantonensis involves rodents as de...Background:Angiostrongyliasis is a food-borne parasitic zoonosis.Human infection is caused by infection with the third-stage larvae of Angiostrongylus cantonensis.The life cycle of A.cantonensis involves rodents as definitive hosts and molluscs as intermediate hosts.This study aims to investigate on the infection status and characteristics of spatial distribution of these hosts,which are key components in the strategy for the prevention and control of angiostrongyliasis.Methods:Three villages from Nanao Island,Guangdong Province,China,were chosen as study area by stratified random sampling.The density and natural infection of Pomacea canaliculata and various rat species were surveyed every three months from December 2015 to September 2016,with spatial correlations of the positive P.canaliculata and the infection rates analysed by ArcGIS,scan statistics,ordinary least squares(OLS)and geographically weighted regression(GWR)models.Results:A total of 2192 P.canaliculata specimens were collected from the field,of which 1190 were randomly chosen to be examined for third-stage larvae of A.cantonensis.Seventy-two Angiostrongylus-infected snails were found,which represents a larval infection rate of 6.1%(72/1190).In total,110 rats including 85 Rattus norvegicus,10 R.flavipectus,one R.losea and 14 Suncus murinus were captured,and 32 individuals were positive(for adult worms),representing an infection rate of 29.1%of the definitive hosts(32/110).Worms were only found in R.norvegicus and R.flavipectus,representing a prevalence of 36.5%(31/85)and 10%(1/10),respectively in these species,but none in R.losea and S.murinus,despite testing as many as 32 of the latter species.Statistically,spatial correlation and spatial clusters in the spatial distribution of positive P.canaliculata and positive rats existed.Most of the spatial variability of the host infection rates came from spatial autocorrelation.Nine spatial clusters with respect to positive P.canaliculata were identified,but only two correlated to infection rates.The results show that corrected Akaike information criterion,R2,R2 adjusted andσ2 in the GWR model were superior to those in the OLS model.Conclusions:P.canaliculata and rats were widely distributed in Nanao Island and positive infection has also been found in the hosts,demonstrating that there was a risk of angiostrongyliasis in this region of China.The distribution of positive P.canaliculata and rats exhibited spatial correlation,and the GWR model had advantage over the OLS model in the spatial analysis of hosts of A.cantonensis.展开更多
Background:The People’s Republic of China(P.R.China)is the presumptive home range of the rat lungworm Angiostrongylus cantonensis,a major aetiological agent of human eosinophilic meningitis.We present a study of the ...Background:The People’s Republic of China(P.R.China)is the presumptive home range of the rat lungworm Angiostrongylus cantonensis,a major aetiological agent of human eosinophilic meningitis.We present a study of the genetic variation of A.cantonensis in P.R.China.Our aim was to deepen the current knowledge pertaining to its origin and global spread from a molecular perspective.Methods:Adult A.cantonensis were collected in the frame of a national survey and identified based on morphological criteria.Polymerase chain reaction(PCR)was employed to amplify the target DNA sequences(cytochrome c oxidase subunit I(cox1),nicotinamide adenine dinucleotide dehydrogenase subunit 1(nad1)and internal transcribed spacer(ITS)).The PCR product of cox1 was directly submitted to sequencing,while clone sequencing was used for nad1 and ITS.The identity of the samples was verified by comparing the sequences to those of accepted A.cantonensis specimens.The specific composition of substitutions in each gene was analysed,and the genotypes were compared based on the complete cox1,nad1 and ITS genes.Results:We characterised the complete mitochondrial genes cox1 and nad1 of 130 specimens and obtained 357 nuclear sequences containing two complete ITS(ITS1 and ITS2)and 5.8S rRNA of the same samples.All specimens were genetically confirmed as A.cantonensis.Two major groups(i.e.I and II)were identified according to the phylogeny of cox1 sequences.Group I could be further categorised into six distinct clades.Almost half of the specimens(47.7%)belong to the clade Ia and 22.3%to the group II.The former was widely distributed across the study region.A variable number of repeat units in three microsatellites was observed,resulting in considerable length variation in ITS.Intragenomic variation of ITS sequences was found in a large proportion of the samples.Genotyping showed a striking difference between mitochondrial DNA and ITS.Conclusions:Our results demonstrate that A.cantonensis is the only rat lungworm species in P.R.China and shows high genetic diversity.Results of diversity and genotyping of A.cantonensis can be impacted by the sequencing strategy and biomarker.Although ITS may be a valuable marker for interspecific identification,it is not suitable for studying the intraspecific variation of A.cantonensis due to its high intragenomic variation and current challenges for direct sequencing.展开更多
Poolingfield specimens could reduce the number of assay and thus increase the efficiency in detecting and screening pathogen infections by polymerase chain reaction(PCR)-based assay.We investigated a pooling strategy in...Poolingfield specimens could reduce the number of assay and thus increase the efficiency in detecting and screening pathogen infections by polymerase chain reaction(PCR)-based assay.We investigated a pooling strategy in diagnosis of Angiostrongylus canto-nensis in Pomacea canaliculata.Two settings of speci-mens were prepared,divided into portions and detected by multiplex PCR.Specimens A was 0.4490 g positive lung tissue of 28 larval nodes from four snails mixed with 1.310 g negative lung tissue from six snails and divided into 32 portions.Specimens B was 0.5448 g positive lung tissue with 26 larval nodes from two snails mixed with 1.092 g negative lung tissue from seven snails and divided into 48 portions.Repeated sampling was performed and sample size-accumulated positive rate curves were drawn.According to the sample size-accumulated positive rate curves,the appropriate sample size of the two specimens were 18 and 15,respectively,which is 0.36–0.58 to the total sample size.These test characteristics and the relevant factors to the sample size would need to be determined in much larger studies and more appropriately infield populations.The result indicates that the number of larval node is not the most important,nor the only factor to the sample size.It also implies the feasibility to detect A.cantonensis in P.canaliculata by pooling strategies.展开更多
Background Gastropoda,the largest class within the phylum Mollusca,houses diverse gut microbiota,and some gastropods serve as intermediate hosts for parasites.Studies have revealed that gut bacteria in gastropods are ...Background Gastropoda,the largest class within the phylum Mollusca,houses diverse gut microbiota,and some gastropods serve as intermediate hosts for parasites.Studies have revealed that gut bacteria in gastropods are associated with various biological aspects,such as growth,immunity and host-parasite interactions.Here,we summarize our current knowledge of gastropod gut microbiomes and highlight future research priorities and perspectives.Methods A literature search was undertaken using PubMed,Web of Science and CNKI for the articles on the gut microbiota of gastropods until December 31,2022.We retrieved a total of 166 articles and identified 73 eligible articles for inclusion in this review based on the inclusion and exclusion criteria.Results Our analysis encompassed freshwater,seawater and land snails,with a specific focus on parasite-transmitting gastropods.We found that most studies on gastropod gut microbiota have primarily utilized 16S rRNA gene sequencing to analyze microbial composition,rather than employing metagenomic,metatranscriptomic,or metabolomic approaches.This comprehensive review provided an overview of the parasites carried by snail species in the context of gut microbiota studies.We presented the gut microbial trends,a comprehensive summary of the diversity and composition,influencing factors,and potential functions of gastropod gut microbiota.Additionally,we discussed the potential applications,research gaps and future perspectives of gut microbiomes in parasite-transmitting gastropods.Furthermore,several strategies for enhancing our comprehension of gut microbiomes in snails were also discussed.Conclusions This review comprehensively summarizes the current knowledge on the composition,potential function,influencing factors,potential applications,limitations,and challenges of gut microbiomes in gastropods,with a specific emphasis on parasite-transmitting gastropods.These findings provide important insights for future studies aiming to understand the potential role of gastropod gut microbiota in controlling snail populations and snail-borne diseases.展开更多
基金supported by the National Natural Science Foundation of China,Nos.82372277(to ZW),82272361(to XS),82271395(to GL)Guangdong Province Basic and Applied Basic Research Fund Project,No.2024A1515010615(to XS)+1 种基金Guangdong Province Natural Youth Promotion Project,No.2314070000241(to GL)Guangzhou Science and Technology Project,No.2025A04J4740(to GL).
文摘Demyelinating diseases of the central nervous system are common,yet few effective strategies for myelin repair and remyelination are available.An increasing number of studies highlight the role of microRNAs(miRNAs)as key regulators of demyelination.miRNA mimics and inhibitors,which are currently in preclinical development,have shown promise as novel therapeutic agents.However,the mechanisms by which they protect myelin are not fully understood.Using a mouse model of acute central nervous system demyelination induced by infection with Angiostrongylus cantonensis,we investigated alterations in miRNA expression in the mouse brain.Our findings revealed a significant early-stage increase in the levels of miR-200,particularly miR-200a and miR-200c.Subsequent analysis demonstrated that combined miR-200a and miR-200c overexpression improved neurobehavioral outcomes and attenuated demyelination in Angiostrongylus cantonensis-infected mice.Further lipid metabolomic profiling indicated that miR-200a and miR-200c synergistically inhibited the production of phosphatase and tensin homolog(PTEN)and activated the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway,as confirmed by double luciferase reporter assay and western blotting.Additionally,in vitro experiments showed that miR-200a and miR-200c protected oligodendrocyte precursor cells from lipopolysaccharide-induced damage and enhanced their survival.Our study indicates the critical role of miR-200a and miR-200c in protecting against central nervous system demyelination by targeting PTEN and modulating key survival pathways.Furthermore,our findings suggest that miR-200a and miR-200c are promising diagnostic biomarkers of and therapeutic targets for treating demyelination-related disorders.
基金Supported by the Hainan Provincial Natural Science Foundation of China,No.824MS173 and No.823MS165the Project of Hainan Province Clinical Medical Center.
文摘BACKGROUND Angiostrongylus cantonensis-induced acute parasitic infection is a rare food-borne disease in clinical practice.Lack of its specific laboratory markers and subsequent difficulty in detecting pathogens cause high misdiagnosis and missed diagnosis rates.CASE SUMMARY A 20-year-old male developed persistent neck and back pain after consuming raw snail meat,followed by urinary retention and low fever.After admission,the patient was misdiagnosed as viral infection and Mycobacterium tuberculosis in central nervous system.After detection of Angiostrongylus cantonensis in blood and cerebrospinal fluid by metagenomics next generation sequencing,albendazole was administered with ceftriaxone and methylprednisolone treatment simultaneously.With effective antiparasitic treatment,the patient weaned from mechanical ventilation successfully and transferred out of intensive care unit for hyperbaric oxygen and rehabilitation treatment.CONCLUSION This case highlights the diagnostic challenges of Angiostrongylus cantonensis infection and the importance of advanced sequencing techniques in identifying rare pathogens.
文摘研究了民间草药甜草O ldenlandia cantonensisHow的化学成分。从乙醇提取物的乙酸乙酯洗脱部分得到新的五环三萜urs-12-en-29-αoic ac id-3β-ol。该化合物结构通过NMR、IR、MS等波谱数据综合解析确定。研究了urs-12-en-29-αoic ac id-3β-ol对重组人DNA拓扑异构酶Ⅰ、肝癌细胞BEL-7402和胃腺癌细胞MCG-803的抑制作用,效果显著,IC50值分别为12.0×10-6、6.5×10-6、8.0×10-6g/mL。由V(石油醚)∶V(乙酸乙酯)=20∶1洗脱得到的低极性成分进行了气相色谱-质谱分析,共鉴定60个化合物,其中长链脂肪族化合物,如烷烃、饱和及不饱和羧酸(酯)含量较丰富,占36.16%,萜类和甾体类化合物分别占6.42%和9.28%。
基金supported by grants from Hainan Provincial Natural Science Foundation(No.808226)
文摘Objective:To understand the current epidemiological status of Angiostrongylus cantonensis in Hainan island and provide the scientific evidences for prevention and control of the disease.Methods:The investigation on nature infection condition of intermediate hosts and final hosts of Angiostrongylus cantonensis were carried out in five counties,Hainan Province, and enzyme linked immunosorbent assay(ELISA) was employed to detect antibodies of Angiostrongylus cantonensis in human hosts.Results:A total of 1 612 molluscs were examined, 21.3%of which harbored L3 of Angiostrongylus cantonensis.Among them,the infection rates of Pomacea canaliculata,Achatina fulica,Cepaea and Phlegm bilineatus were 12.3696(64/518), 22.66%(121/534),20.93%(9/43),and 28.24%(146/517),respectively.Of the 118 rats trapped,13 Rattus norvegicus were found to be infected with Angiostrongylus cantonensis.A total of 459 serum samples were collected and tested.92 serum samples were Angiostrongylus cantonensis antibody-positive.Conclusions:The survey revealed a wide distribution of Angiostrongylus cantonensis in Hainan island.Pomacea canaUculata and Achatina fulica are main intermediate hosts of Angiostrongylus cantonensis.Rattus novegicus is a nature definitive host,indicating that a considerable number of people are at risk of angiostrongyliasis.Health education,rigorous food inspection and surveillance are all needed to prevent angiostrongyliasis outbreaks in future.
基金funded by Division of Research Administration,Naresuan University
文摘Objective:To survey the Angiostrongylus cantonensis(A.cantonensis) or the rat lungworm in a rat,definitive host,and in a giant African land snail(Achatina fulica),the intermediate host,in Phitsanulok,Thailand.Methods:Rats and giant African land snails were captured from Tha Pho sub-district,Phitsanulok,Thailand.Rats were killed and examined for adult A.cantonensis. The artificial digestion method following Baermann technique were used for isolation third stage larvae of A.cantonensis.Results:Sixty-two rats were captured and they were identified as Rattus argentiventer,Rattus rattus(R.rattus),Bandicota savilei,and Bandicota indica but only one animal(R.rattus) of 62 rats(1.61%) was positive with adult worm of A.cantonensis.The third stage larvae of A.cantonensis were examined on 307 Angiostrongylus fulica snails.It was found that the overall infection rate was 12.38%(38 infected out of 307 Achatina snails).Conclusions: This study demonstrates that A.cantonensis is available in the natural hosts of Phitsanulok.This suggests that the transmissions of this parasite to human may occur in this region.
基金Supported by Collaborative Innovation Center for Zhuang and Yao Medicines(GJKY[2013]20)Guangxi Key Laboratory of Zhuang and Yao Medicine(GKJZ[2014]32)+3 种基金Guangxi Key Discipline of Zhuang Medicine(GJKY[2013]16)Masters Innovation Project of Postgraduate Education Innovation Program of Guangxi University of Chinese Medicine(YJSP201738)Guangxi Key Discipline of Traditional Chinese pharmacology(0501802815)Development of Zhuangyao Huotanmu Capsule for the Treatment of Hepatitis B(NKF[2018]11)
文摘[Objectives] This study was conducted to establish a characteristic fingerprinting research method for the chemical constituents of the Zhuang medicine Pholidota cantonensis Rolfe.and its characteristic fingerprint of chemical constituents,in order to identify P.cantonensis.[Methods] Ten batches of P.cantonensis from different habitats in Guangxi and out of Guangxi (Shaoguan of Guangdong Province) were determined.The materials were extracted in 80% methanol ultrasonically for 1.5 h under the material-to-liquid ratio of 2.5 g/80 ml.The HPLC determination was carried out using an Agilent 1260 HPLP instrument equipped with an Agilent5 TC-C18 (2) column at the column temperature of 30 ℃,the wavelength of 280 nm and the injection volume of 10 μl using acetonitrile-0.4% phosphoric acid as the mobile phase and chlorogenic acid as the reference peak,and the detection took 58 min.[Results] The characteristic fingerprint of the chemical constituents of P.cantonensis were obtained,and the three chromatographic peaks of gallic acid,chlorogenic acid and syringaldehyde were compared.[Conclusions] This study can provide reference for the identification of the Zhuang medicine P.cantonensis and provide guarantee for the clinical use of Chinese medicine.
基金Supported by Zhuang Yao Medicine Collaborative Innovation Center(GJKY[2013]20)Guangxi Key Laboratory of Zhuang Yao Medicine(GKJZ[2014]32)+1 种基金Guangxi Key Discipline:Zhuang pharmacy(GJKY[2013]16)Chinese Traditional Medicine Innovation Theory and Drug Efficacy Study of Bagui Scholars(J13162)
文摘Research progress of pharmacognostical identification and chemical composition of Pholidota cantonensis Rolfe. was reviewed. This paper will facilitate assurance of the safety of clinical treatment.
基金supported by the Southeast Asia-Europe Joint Funding Scheme for Research and Innovation(SEAEUROPEJFS19IN-053)the Czech Science Foundation(No.22-26136S)Elena Izquierdo-Rodriguez was supported by the M-ULL scholarship(M-ULL,convocatoria 2019),Czech Republic.The work of Lucia Anettováwas also supported by the Czech Academy of Sciences,ABERA Project.
文摘Objectives:Fish are hypothesized to act as paratenic hosts for the zoonotic nematode Angiostrongylus cantonensis,which causes human eosinophilic meningitis.There is a lack of data confirming the relevance of fish in A.cantonensis life cycle and their contribution to human infection.Materials and Methods:We conducted a series of experiments to investigate the survival and infectivity of A.cantonensis larvae in Clarias gariepinus(catfish;n=30)and Oreochromis niloticus(tilapia;n=24).Each fish was inoculated with 10000 third-stage larvae(L3).Larval survival was assessed through artificial digestion of fish tissues 1 week,2 weeks,and 3 weeks post-infection.To investigate the early stages of infection,four catfish were inoculated with 10000 L3 each and sacrificed 3 d post-infection.Quantitative polymerase chain reaction(qPCR)analysis and histopathological examination were performed to evaluate larval distribution and tissue reactions.Two infected catfish,sacrificed 1 week post-infection,were used to feed Wistar rats.Results:After 45 d,the rats did not shed first-stage larvae(L1),indicating the absence of infection.One week post-infection,dead larvae were present in the digested tissues of both fish species,and the same was observed 2 weeks and 3 weeks after exposure.qPCR analysis revealed that the intestine was the most heavily infected organ.Histopathological examination identified dead larvae within granulomas in both the intestines and liver.Early-stage infection experiment showed that fish sacrificed 3 d post-inoculation contained viable L3,which was infective to Wistar rats.Conclusions:While A.cantonensis L3 can survive and remain infective in fish for a short period,they typically die within first few days postinfection.This suggests that fish may not be significant long-term paratenic hosts for A.cantonensis but may play a temporary role in its transmission to mammals(including humans)and birds.These results are consistent with previous studies on freshwater shrimps and highlight the importance of understanding aquatic host interactions in the epidemiology of this zoonotic foodborne pathogen.
文摘Background Angiostrongyliasis cantonensis is a worldwide-existing parasitic disease. However, the relevant reports on its radiological appearances are limited. In this study, we investigated magnetic resonance imaging （MRI） features of eosinophilic meningoencephalitis in a group of consecutive patients caused by human infection with Angiostrongylus cantonensis after eating freshwater snails. Methods We performed brain MR imaging on 74 patients with angiostrongyliasis cantonensis. The scanner was a 0.5T unit. For each patient MR pulse sequences of $E Tl-weighted image （TlWl） and FSE T2-weighted image （T2Wl） were used. After intravenous administration of gadolinium chelate （Gd-DTPA） repeated Tl-weighted images were obtained. MRI features of the lesions in the brain and meninges were analyzed and recorded after observing initial and follow-up MR images. The classification of the types of angiostrongyliasis cantonensis infection was done on the basis of locations of the disorders. Results Forty-one （55%） normal and 33 （45%） abnormal MRI appearances in the brain were found. According to locations of the disorders, the types of angiostrongyliasis cantonensis infection were determined as follows： seventeen cases of type meningitis, three of type myeloencephalitis, one of type neuritis and twelve of mixed type （eight of type ventriculitis and five of type pneumonitis were among them）. In type meningitis, abnormal leptomeningeal enhancement was visualized. In type myeloencephalitis, lesions in the brain parenchyma may have iso- or slightly low signal intensity on TlWl and high signal intensity on T2Wl. Enhanced nodules in various shapes were shown on gadolinium-enhanced TlWl, a few lesions appeared as crescent enhancements and some lesions did not reveal abnormal enhancement. Other than brain lesions, an enhanced nodule was seen in the cervical spinal cord in one patient. In type ventriculitis, brain ventricular enlargement was demonstrated. In type neuritis, a nodule and abnormal enhancement in the right optic nerve was revealed. In type pneumonitis, patchy ground-glass opacity and consolidative lesions at the periphery of the lungs were seen. Follow-up results indicated that most lesions in the brain could resolve in 2 to 8 weeks. Conclusions Angiostrongyliasis cantonensis presented as both single type and mixed type. Nodular enhancing lesions in the brain and/or linear enhancement in the leptomeninges were the main findings, while crescent enhancement would be the characteristic sign of the disease on gadolinium-enhanced TlWI. Focal edematous changes without contrast enhancement in the brain could be seen on MRI in some cases.
基金This study was funded by The Special Foundation of Basic Science and Technology Resources Survey of Ministry of Science and Technology of China(No.2017FY101203)the National Key Research and Development Program of China(No.2016YFC1202000,2016YFC1202001)the National Science and Technology Major Project of China(No.2012ZX1004–220,2008ZX1004–011).
文摘Background:Angiostrongyliasis is a food-borne parasitic zoonosis.Human infection is caused by infection with the third-stage larvae of Angiostrongylus cantonensis.The life cycle of A.cantonensis involves rodents as definitive hosts and molluscs as intermediate hosts.This study aims to investigate on the infection status and characteristics of spatial distribution of these hosts,which are key components in the strategy for the prevention and control of angiostrongyliasis.Methods:Three villages from Nanao Island,Guangdong Province,China,were chosen as study area by stratified random sampling.The density and natural infection of Pomacea canaliculata and various rat species were surveyed every three months from December 2015 to September 2016,with spatial correlations of the positive P.canaliculata and the infection rates analysed by ArcGIS,scan statistics,ordinary least squares(OLS)and geographically weighted regression(GWR)models.Results:A total of 2192 P.canaliculata specimens were collected from the field,of which 1190 were randomly chosen to be examined for third-stage larvae of A.cantonensis.Seventy-two Angiostrongylus-infected snails were found,which represents a larval infection rate of 6.1%(72/1190).In total,110 rats including 85 Rattus norvegicus,10 R.flavipectus,one R.losea and 14 Suncus murinus were captured,and 32 individuals were positive(for adult worms),representing an infection rate of 29.1%of the definitive hosts(32/110).Worms were only found in R.norvegicus and R.flavipectus,representing a prevalence of 36.5%(31/85)and 10%(1/10),respectively in these species,but none in R.losea and S.murinus,despite testing as many as 32 of the latter species.Statistically,spatial correlation and spatial clusters in the spatial distribution of positive P.canaliculata and positive rats existed.Most of the spatial variability of the host infection rates came from spatial autocorrelation.Nine spatial clusters with respect to positive P.canaliculata were identified,but only two correlated to infection rates.The results show that corrected Akaike information criterion,R2,R2 adjusted andσ2 in the GWR model were superior to those in the OLS model.Conclusions:P.canaliculata and rats were widely distributed in Nanao Island and positive infection has also been found in the hosts,demonstrating that there was a risk of angiostrongyliasis in this region of China.The distribution of positive P.canaliculata and rats exhibited spatial correlation,and the GWR model had advantage over the OLS model in the spatial analysis of hosts of A.cantonensis.
基金This work was supported by International Development and Research Centre(IDRCCanada)(grant no.105509-00001002-023)the International Society of Infectious Diseases(small grant 2007 fall).
文摘Background:The People’s Republic of China(P.R.China)is the presumptive home range of the rat lungworm Angiostrongylus cantonensis,a major aetiological agent of human eosinophilic meningitis.We present a study of the genetic variation of A.cantonensis in P.R.China.Our aim was to deepen the current knowledge pertaining to its origin and global spread from a molecular perspective.Methods:Adult A.cantonensis were collected in the frame of a national survey and identified based on morphological criteria.Polymerase chain reaction(PCR)was employed to amplify the target DNA sequences(cytochrome c oxidase subunit I(cox1),nicotinamide adenine dinucleotide dehydrogenase subunit 1(nad1)and internal transcribed spacer(ITS)).The PCR product of cox1 was directly submitted to sequencing,while clone sequencing was used for nad1 and ITS.The identity of the samples was verified by comparing the sequences to those of accepted A.cantonensis specimens.The specific composition of substitutions in each gene was analysed,and the genotypes were compared based on the complete cox1,nad1 and ITS genes.Results:We characterised the complete mitochondrial genes cox1 and nad1 of 130 specimens and obtained 357 nuclear sequences containing two complete ITS(ITS1 and ITS2)and 5.8S rRNA of the same samples.All specimens were genetically confirmed as A.cantonensis.Two major groups(i.e.I and II)were identified according to the phylogeny of cox1 sequences.Group I could be further categorised into six distinct clades.Almost half of the specimens(47.7%)belong to the clade Ia and 22.3%to the group II.The former was widely distributed across the study region.A variable number of repeat units in three microsatellites was observed,resulting in considerable length variation in ITS.Intragenomic variation of ITS sequences was found in a large proportion of the samples.Genotyping showed a striking difference between mitochondrial DNA and ITS.Conclusions:Our results demonstrate that A.cantonensis is the only rat lungworm species in P.R.China and shows high genetic diversity.Results of diversity and genotyping of A.cantonensis can be impacted by the sequencing strategy and biomarker.Although ITS may be a valuable marker for interspecific identification,it is not suitable for studying the intraspecific variation of A.cantonensis due to its high intragenomic variation and current challenges for direct sequencing.
文摘Poolingfield specimens could reduce the number of assay and thus increase the efficiency in detecting and screening pathogen infections by polymerase chain reaction(PCR)-based assay.We investigated a pooling strategy in diagnosis of Angiostrongylus canto-nensis in Pomacea canaliculata.Two settings of speci-mens were prepared,divided into portions and detected by multiplex PCR.Specimens A was 0.4490 g positive lung tissue of 28 larval nodes from four snails mixed with 1.310 g negative lung tissue from six snails and divided into 32 portions.Specimens B was 0.5448 g positive lung tissue with 26 larval nodes from two snails mixed with 1.092 g negative lung tissue from seven snails and divided into 48 portions.Repeated sampling was performed and sample size-accumulated positive rate curves were drawn.According to the sample size-accumulated positive rate curves,the appropriate sample size of the two specimens were 18 and 15,respectively,which is 0.36–0.58 to the total sample size.These test characteristics and the relevant factors to the sample size would need to be determined in much larger studies and more appropriately infield populations.The result indicates that the number of larval node is not the most important,nor the only factor to the sample size.It also implies the feasibility to detect A.cantonensis in P.canaliculata by pooling strategies.
基金supported by the National Key R&D Program of China(Nos.2020YFC1200100,2020YFC1200103,2021YFC2300800 and 2016YFC1200500)the National Natural Science Foundation of China(Nos.82202560,82161160343 and 82272361)+5 种基金the R&D Program in Key Areas of Guangdong Province(No.2022B1111030002)the Fundamental Research Funds for the Central University(No.22qntd4813)the Science and Technology Planning Project of Guangdong Province(No.2021B1212040017)the 111 Project(No.B12003)the 6th Nuclear Energy R&D Project(No.20201192)the National Parasitic Resource Center and Ministry of Science and Technology(No.NPRC-2019-194-30).
文摘Background Gastropoda,the largest class within the phylum Mollusca,houses diverse gut microbiota,and some gastropods serve as intermediate hosts for parasites.Studies have revealed that gut bacteria in gastropods are associated with various biological aspects,such as growth,immunity and host-parasite interactions.Here,we summarize our current knowledge of gastropod gut microbiomes and highlight future research priorities and perspectives.Methods A literature search was undertaken using PubMed,Web of Science and CNKI for the articles on the gut microbiota of gastropods until December 31,2022.We retrieved a total of 166 articles and identified 73 eligible articles for inclusion in this review based on the inclusion and exclusion criteria.Results Our analysis encompassed freshwater,seawater and land snails,with a specific focus on parasite-transmitting gastropods.We found that most studies on gastropod gut microbiota have primarily utilized 16S rRNA gene sequencing to analyze microbial composition,rather than employing metagenomic,metatranscriptomic,or metabolomic approaches.This comprehensive review provided an overview of the parasites carried by snail species in the context of gut microbiota studies.We presented the gut microbial trends,a comprehensive summary of the diversity and composition,influencing factors,and potential functions of gastropod gut microbiota.Additionally,we discussed the potential applications,research gaps and future perspectives of gut microbiomes in parasite-transmitting gastropods.Furthermore,several strategies for enhancing our comprehension of gut microbiomes in snails were also discussed.Conclusions This review comprehensively summarizes the current knowledge on the composition,potential function,influencing factors,potential applications,limitations,and challenges of gut microbiomes in gastropods,with a specific emphasis on parasite-transmitting gastropods.These findings provide important insights for future studies aiming to understand the potential role of gastropod gut microbiota in controlling snail populations and snail-borne diseases.
