Burden of Cryptosporidium Infections in the Yangtze River Delta in China in the 21st Century: A One Health Perspective

Cryptosporidiosis is a leading cause of diarrheal disease in some populations, including young children and people with compromised immune systems. The epidemiology of Cryptosporidium , which is transmitted mainly through waterborne routes, has been a serious public health concern. Cryptosporidiosis is closely associated with animals and the shared environment, and is well suited to a One Health approach to prevention and control. In China, Cryptosporidium investigations in humans, various animal species, water bodies and other environments have been widely conducted, including in the Yangtze River Delta, which encompasses Shanghai, Jiangsu, Zhejiang and Anhui. With the increasing integrated development of the Yangtze River Delta, advance preparation and effective monitoring are necessary to prevent outbreaks of neglected tropical diseases, such as cryptosporidiosis, and to contribute to infectious disease prevention and control in the entire region. Moreover, the epidemiological surveillance of infectious diseases is a critical public health measure. This article reviews the burden of Cryptosporidium in the Yangtze River Delta at the human-animal-environment interface, as reported since 2001, and identifies the deficiencies and challenges in epidemiological studies of Cryptosporidium in this region from a One Health perspective, to provide basic information for the formulation of prevention and control strategies

De novo assembly and transcriptome characterization: novel insights into the natural resistance mechanisms of Microtus fortis against Schistosoma japonicum

BACKGROUND: Microtus fortis is a non-permissive host of Schistosoma japonicum. It has natural resistance against schistosomes, although the precise resistance mechanisms remain unclear. The paucity of genetic information for M. fortis limits the use of available immunological methods. Thus, studies based on high-throughput sequencing technologies are required to obtain information about resistance mechanisms against S. japonicum. RESULTS: Using Illumina single-end technology, a de novo assembly of the M. fortis transcriptome produced 67,751 unigenes with an average length of 868 nucleotides. Comparisons were made between M. fortis before and after infection with S. japonicum using RNA-seq quantification analysis. The highest number of differentially expressed genes (DEGs) occurred two weeks after infection, and the highest number of down-regulated DEGs occurred three weeks after infection. Simultaneously, the strongest pathological changes in the liver were observed at week two. Gene ontology terms and pathways related to the DEGs revealed that up-regulated transcripts were involved in metabolism, immunity and inflammatory responses. Quantitative real-time PCR analysis showed that patterns of gene expression were consistent with RNA-seq results. CONCLUSIONS: After infection with S. japonicum, a defensive reaction in M. fortis commenced rapidly, increasing dramatically in the second week, and gradually decreasing three weeks after infection. The obtained M. fortis transcriptome and DEGs profile data demonstrated that natural and adaptive immune responses, play an important role in M. fortis immunity to S. japonicum. These findings provide a better understanding of the natural resistance mechanisms of M. fortis against schistosomes. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi: 10.1186/1471-2164-15-417) contains supplementary material, which is available to authorized users

Altered Gut Microbiota Composition in Subjects Infected With Clonorchis sinensis

Clonorchiasis is an infectious disease caused by helminths of Clonorchis sinensis (C. sinensis). The adult parasite mainly inhabits the bile duct and gall bladder, and results in various complications to the hepatobiliary system. The amount of bile secreted into the intestine is reduced in cases of C. sinensis infection, which may alter the pH of the gut and decrease the amount of surfactant protein D released from the gallbladder. However, the impact of parasitic infection on the human gut microbiome remains unclear. To this end, we examined the gut microbiota composition in 47 modified Kato–Katz thick smear-positive (egg-positive) volunteers and 42 healthy controls from five rural communities. Subjects were grouped into four sub-populations based on age and infection status. High-throughput 16S rRNA gene sequencing revealed significant changes in alpha diversity between EP1 and EN1. The beta diversity showed alterations between C. sinensis-infected subjects and healthy controls. In C. sinensis infected patients, we found the significant reduction of certain taxa, such as Bacteroides and anti-inflammatory Bifidobacterium (P < 0.05). Bacteroides, a predominant gut bacteria in healthy populations, was negatively correlated with the number of C. sinensis eggs per gram (EPG, r = −0.37, P adjust < 0.01 in 20–60 years old group; r = −0.64, P adjust = 0.04 in the 60+ years old group). What’s more, the reduction in the abundance of Bifidobacterium, a common probiotic, was decreased particularly in the 60 + years old group (r = −0.50, P = 0.04). The abundance of Dorea, a potentially pro-inflammatory microbe, was higher in infected subjects than in healthy individuals (P < 0.05). Variovorax was a unique bacteria that was only detected in infected subjects. These results clearly demonstrate the significant influence of C. sinensis infection on the human gut microbiota and provided new insights into the control, prevention, diagnosis, and clinical study of clonorchiasis through the human gut microbiota

Molecular Epidemiology and the Control and Prevention of Cystic Echinococcosis in China: What is Known from Current Research

As a zoonotic parasitic disease, echinococcosis is a severe global public health issue caused by the larvae of Echinococcus spp. Not only does echinococcosis threaten human health, but echinococcosis also causes enormous economic losses. China ranks first in the range of echinococcosis endemic areas, the number of infected patients, and the number of threatened populations worldwide, hence the most severe echinococcosis epidemic currently exists in China. Cystic echinococcosis (CE) is the most important form of echinococcosis. Accounting for nearly 80% of all echinococcosis cases, CE is the most important cause of the echinococcosis disease burden. Echinococcus granulosus sensu lato ( s.l. ) is the causative agent of CE and is considered a multi-genotype complex. The different genotypes of E. granulosus s.l. exhibit differences in morphology, transmission route, and epidemic characteristics. The corresponding clinical characteristics, clinical treatment, and vaccine responses also differ between the genotypes of E. granulosus s.l. During the past two decades, China has implemented echinococcosis control and prevention programs in endemic areas with impressive results. Specifically, the prevalence of echinococcosis has decreased. With such extraordinary achievements, precise control and prevention of the genotypes of E. granulosus s.l. have never been more important. Nevertheless, insufficient attention has been devoted to molecular epidemiology in the current control programs, and the lack of genotype data from humans and animal hosts exacerbates the situation. Hence, based on the ongoing control and surveillance programs, collecting additional molecular epidemiologic data and geographic information from humans and animals, as well as monitoring the clinical manifestations and drug and vaccine responses of the different genotypes, are invaluable for establishing a molecular epidemiologic database, which in turn can enhance the precise control and prevention of echinococcosis

Induction of hepatic fibrosis in mice with schistosomiasis by extracellular microRNA-30 derived from Schistosoma japonicum eggs

BackgroundSchistosomiasis is a zoonotic parasitic disorder induced by the infestation of schistosomes, a genus of trematodes. MicroRNAs (miRNAs) in egg-derived exosomes are crucial for modulating the host’s immune responses and orchestrating the pathophysiological mechanisms. Although the exosomes secreted by S. japonicum contain abundant miRNAs, the specific roles of these miRNAs in the pathogenesis of schistosomiasis-induced hepatic fibrosis are yet to be comprehensively elucidated. The egg exosomes of S. japonicum secrete miRNA-30, a novel miRNA.MethodsIn vitro, the effect of miRNA-30 was evaluated by transfecting HSCs with miRNA mimics. The target gene biosignature for miRNA-30 was predicted using the miRDB software. The effect of miRNA-30 in hepatic fibrosis was evaluated by either elevating its expression in healthy mice or by inhibiting its activity in infected mice by administration of recombinant adeno-associated virus serotype eight vectors expressing miRNA-30 or miRNA sponges.ResultsThis novel miRNA can activate hepatic stellate cells (HSCs), the prinary effector cells of hepatic fibrosis, in vitro, i.e., it significantly increases the fibrogenic factors Col1(α1), Col3(α1), and α-SMA at both mRNA and protein levels. In addition, miRNA-30 may activate HSCs by targeting the host RORA gene. In addition, in vivo experiments were conducted by administering a recombinant adeno-associated viral vector to modulate the expression levels of miRNA-30. The overexpression of miRNA-30 in healthy mice significantly elevated the expression of Col1(α1), Col3(α1), and α-SMA at both the transcriptomic and proteomic scales. This overexpression was coupled with a pronounced augmentation in the hepatic hydroxyproline content. Conversely, the in vivo silencing of miRNA-30 in infected mice induced a considerable reduction in the size of hepatic granulomas and areas of collagen deposition. Hence, in vivo, modulation of miRNA-30 expression may play a pivotal role in ameliorating the severity of hepatic fibrosis in mice afflicted with S. japonica.ConclusionsThe study results suggest that miRNA-30 may augment schistosomiasis-induced hepatic fibrosis through a probable interaction with the host RORA. Our study may improve the current theoretical framework regarding cross-species regulation by miRNAs of hepatic fibrosis in schistosomiasis

The single-cell landscape of cystic echinococcosis in different stages provided insights into endothelial and immune cell heterogeneity

IntroductionHydatid cysts and angiogenesis are the key characteristics of cystic echinococcosis, with immune cells and endothelial cells mediating essential roles in disease progression. Recent single-cell analysis studies demonstrated immune cell infiltration after Echinococcus granulosus infection, highlighting the diagnostic and therapeutic potential of targeting certain cell types in the lesion microenvironment. However, more detailed immune mechanisms during different periods of E. granulosus infection were not elucidated.MethodsHerein, we characterized immune and endothelial cells from the liver samples of mice in different stages by single-cell RNA sequencing.ResultsWe profiled the transcriptomes of 45,199 cells from the liver samples of mice at 1, 3, and 6 months after infection (two replicates) and uninfected wild-type mice. The cells were categorized into 26 clusters with four distinct cell types: natural killer (NK)/T cells, B cells, myeloid cells, and endothelial cells. An SPP1+ macrophage subset with immunosuppressive and pro-angiogenic functions was identified in the late infection stage. Single-cell regulatory network inference and clustering (SCENIC) analysis suggested that Cebpe, Runx3, and Rora were the key regulators of the SPP1+ macrophages. Cell communication analysis revealed that the SPP1+ macrophages interacted with endothelial cells and had pro-angiogenic functions. There was an obvious communicative relationship between SPP1+ macrophages and endothelial cells via Vegfa–Vegfr1/Vegfr2, and SPP1+ macrophages interacted with other immune cells via specific ligand–receptor pairs, which might have contributed to their immunosuppressive function.DiscussionOur comprehensive exploration of the cystic echinococcosis ecosystem and the first discovery of SPP1+ macrophages with infection period specificity provide deeper insights into angiogenesis and the immune evasion mechanisms associated with later stages of infection

Occurrence and genetic characterization of Enterocytozoon bieneusi in pet dogs in Yunnan Province, China

Enterocytozoon bieneusi is the most common microsporidian species in humans and can affect over 200 animal species. Considering possible increasing risk of human E. bieneusi infection due to close contact with pet dogs and identification of zoonotic E. bieneusi genotypes, 589 fresh fecal specimens of pet dogs were collected from Yunnan Province, China to determine the occurrence of E. bieneusi, characterize dog-derived E. bieneusi isolates, and assess their zoonotic potential at the genotype level. Enterocytozoon bieneusi was identified and genotyped by PCR and sequencing of the internal transcribed spacer (ITS) region of the ribosomal RNA (rRNA) gene. Twenty-nine specimens (4.9%) were positive. A statistical difference was observed in occurrence rates of E. bieneusi in pet dogs among 11 sampling sites by Fisher’s exact test. Fifteen genotypes were identified and all of them phylogenetically belonged to zoonotic group 1, including four known genotypes (EbpC, D, Peru 8, and Henan-III) and 11 novel genotypes. Genotype Henan-III was reported in dogs for the first time. The finding of known genotypes found previously in humans and novel genotypes falling into zoonotic group 1 indicates that dogs may play a role in the transmission of E. bieneusi to humans in the investigated areas

Prevalence of the Cryptosporidium Pig Genotype II in Pigs from the Yangtze River Delta, China

Background: Cryptosporidium spp. is prevalent globally, pigs are an important Cryptosporidium reservoir. In China, little data regarding rates of Cryptosporidium infections in pigs are available. The present study was therefore aimed at characterizing the distribution of Cryptosporidium species in pigs from two different cities, Shaoxing and Shanghai, from the Yangtze River delta. Methodology/Principal Findings: Nested PCR to amplify the 18S rRNA locus on DNA extracted from fecal samples (n = 94) revealed the positive rate of Cryptosporidium in pigs from two cities was approximately 17.0%. The positive rates in Shanghai and Shaoxing were 14.3 % and 25.0 % respectively. Amplified sequences were verified by sequencing. The identified strain belonged to the C. pig genotype II using BLAST analysis in the NCBI database. Conclusion/Significance: Our finding of Cryptosporidium pig genotype II in pigs in the Yangtze River delta area suggests that pig farms in this region must be considered a public health threat and proper control measures be introduced