Clonorchis sinensis and clonorchiasis, an update

Exploration of the Amino Acid Metabolic Profiling and Pathway in Clonorchis sinensis-Infected Rats Revealed by the Targeted Metabolomic Analysis

Background: Clonorchiasis remains a serious public health problem. However, the molecular mechanism underlying clonorchiasis remains largely unknown. Amino acid (AA) metabolism plays key roles in protein synthesis and energy sources, and improves immunity in pathological conditions. Therefore, this study aimed to explore the AA profiles of spleen in clonorchiasis and speculate the interaction between the host and parasite. Methods: Here targeted ultrahigh performance liquid chromatography multiple reaction monitoring mass spectrometry was applied to discover the AA profiles in spleen of rats infected with Clonorchis sinensis. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis (KEGG) was performed to characterize the dysregulated metabolic pathways. Results: Pathway analysis revealed that phenylalanine, tyrosine, and tryptophan biosynthesis and β-alanine metabolism were significantly altered in clonorchiasis. There were no significant correlations between 14 significant differential AAs and interleukin (IL)-1β. Although arginine, asparagine, histidine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine were positively correlated with IL-6, IL-10, tumor necrosis factor (TNF)-α as well as aspartate aminotransferase and alanine aminotransferase; β-alanine and 4-hydroxyproline were negatively correlated with IL-6, IL-10, and TNF-α. Conclusion: This study reveals the dysregulation of AA metabolism in clonorchiasis and provides a useful insight of metabolic mechanisms at the molecular level.

V. Q, Sun L, Yang Y, Liu M, Liu X, Li C, Tang B. Revealing the dynamic whole transcriptome landscape of Clonorchis sinensis: Insights into the regulatory roles of noncoding RNAs and microtubule-related genes in development

Clonorchis sinensis is a significant zoonotic food-borne parasite that causes a range of hepatobiliary diseases, which in severe cases can even lead to cholangiocarcinoma. To explore new diagnostic and treatment strategies, the dynamic RNA regulatory processes across different developmental stages of C. sinensis were analyzed by using whole-transcriptome sequencing. The chromosomal-level genome of C. sinensis was used for sequence alignment and annotation. In this study, we identified a total of 59,103 RNAs in the whole genome, including 2,384 miRNAs, 25,459 mRNAs, 27,564 lncRNAs and 3,696 circRNAs. Differential expression analysis identified 6,556 differentially expressed mRNAs, 2,231 lncRNAs, 877 miRNAs and 20 circRNAs at different developmental stages. Functional enrichment analysis highlighted the critical role of microtubule-related biological processes in the growth and development of C. sinensis. And coexpression analysis revealed 97 lncRNAs and 85 circRNAs that were coexpressed with 42 differentially expressed mRNAs that associated with microtubules at different developmental stages of C. sinensis. The expression of the microtubule-related genes dynein light chain 2 (DLC2) and dynein light chain 4 (DLC4) increased with C. sinensis development, and DLC2/4 could be inhibited by albendazole. Finally, by constructing competing endogenous RNA (ceRNA) networks, the lncRNA-miRNA-mRNA and circRNA-miRNA-mRNA regulatory relationships were constructed, and the ceRNA networks of MSTRG.14258.5-novel_miR_2287-newGene_28215 and MSTRG.14258.5-novel_miR_2216-CSKR_109340 were verified. This study suggests, through whole transcriptome sequencing, that the context of microtubule regulation may play an essential role in the development and growth of C. sinensis.

Epidemiology and Geographical Distribution of Human Trematode Infections

Digenetic trematodes infecting humans are more than 109 species that belong to 49 genera all over the world. According to their habitat in the definitive hosts, they are classified as 6 blood flukes (Schistosoma japonicum. S. mekongi, S. malayensis, S. mansoni, S. intercalatum, and S. haematobium), 15 liver flukes (Fasciola hepatica, F. gigantica, Clonorchis sinensis, Opisthorchis viverrini, O. felineus, Dicrocoelium dendriticum, D. hospes, Metorchis bilis, M. conjunctus, M. orientalis, Amphimerus sp., A. noverca, A. pseudofelineus, Pseudamphistomum truncatum, and P. aethiopicum), nine lung flukes (Paragonimus westermani, P. heterotremus, P. skrjabini, P. skrjabini miyazakii, P. kellicotti, P. mexicanus, P. africanus, P. uterobilateralis, and P. gondwanensis), 30 heterophyid intestinal flukes (Metagonimus yokogawai, M. takahashii, M. miyatai, M. suifunensis, M. katsuradai, M. pusillus, M. minutus, Heterophyes heterophyes, H. nocens, H. dispar, Haplorchis taichui, H. pumilio, H. yokogawai, H. vanissinus, Centrocestus formosanus, C. armatus, C. cuspidatus, C. kurokawai, Procerovum calderoni, P. varium, Pygidiopsis genata, P. summa, Stictodora fuscata, S. lari, Stellantchasmus falcatus, Heterophyopsis continua, Acanthotrema felis, Apophallus donicus, Ascocotyle longa, and Cryptocotyle lingua), 24 echinostome intestinal flukes (Echinostoma revolutum, E. cinetorchis, E. mekongi, E. paraensei, E. ilocanum, E. lindoense, E. macrorchis, E. angustitestis, E. aegyptica, Isthmiophora hortensis, I. melis, Echinochasmus japonicus, E. perfoliatus, E. lilliputanus, E. caninus, E. jiufoensis, E. fujianensis, Artyfechinostomum malayanum, A. sufrartyfex, A. oraoni, Acanthoparyphium tyosenense, Echinoparymphium recurvatum, Himasthla muehlensi, and Hypoderaeum conoideum), 23 miscellaneous intestinal flukes (Brachylaima cribbi, Caprimolgorchis molenkampi, Phaneropsolus bonnei, P. spinicirrus, Cotylurus japonicus, Fasciolopsis buski, Gastrodiscoides hominis, Fischoederius elongatus, Watsonius watsoni, Gymnophalloides seoi, Gynaecotyla squatarolae, Microphallus brevicaeca, Isoparorchis hypselobagri, Nanophyetus salmincola, N. schikobalowi, Neodiplostomum seoulense, Fibricola cratera, Plagiorchis muris, P. vespertilionis, P. harinasutai, P. javensis, P. philippinensis, and Prohemistomum vivax), one throat fluke (Clinostomum complanatum), and one pancreatic fluke (Eurytrema pancreaticum). The mode of transmission to humans includes contact with cercariae contaminated in water (schistosomes) or ingestion of raw or improperly cooked food, including fish (liver flukes, heterophyid flukes, echinostomes, and throat flukes), snails (echinostomes, brachylaimids, and gymnophallid flukes), amphibia, reptiles (neodiplostomes), aquatic vegetables (fasciolids and amphistomes), and insect larvae or adults (lecithodendriids, plagiorchiids, and pancreatic flukes). Praziquantel has been proven to be highly effective against almost all kinds of trematode infections except Fasciola spp. Epidemiological surveys and detection of human infections are required for a better understanding of the prevalence, intensity of infection, and geographical distribution of each trematode species.

Liver Flukes: Clonorchis and Opisthorchis

Clonorchis sinensis, Opisthorchis viverrini and O. felineus are liver flukes of human and animal pathogens occurring across much of Europe and Asia. Nevertheless, they are often underestimated compared to other, better known neglected diseases in spite of the fact that many millions of people are infected and hundreds of millions are at risk. This is possibly because of the chronic nature of the infection and disease and that it takes several decades prior to a life-threatening pathology to develop. Several studies in the past decade have provided more information on the molecular biology of the liver flukes which clearly lead to better understanding of parasite biology, systematics and population genetics. Clonorchiasis and opisthorchiasis are characterized by a chronic infection that induces hepatobiliary inflammation, especially periductal fibrosis, which can be detected by ultrasonography. These chronic inflammations eventually lead to cholangiocarcinoma (CCA), a usually fatal bile duct cancer that develops in some infected individuals. In Thailand alone, opisthorchiasis-associated CCA kills up to 20,000 people every year and is therefore of substantial public health importance. Its socioeconomic impacts on impoverished families and communities are considerable. To reduce hepatobiliary morbidity and CCA, the primary intervention measures focus on control and elimination of the liver fluke. Accurate diagnosis of liver fluke infections in both human and other mammalian, snail and fish intermediate hosts is important for achieving these goals. While the short-term goal of liver fluke control can be achieved by praziquantel chemotherapy, a comprehensive health education package targeting school children is believed to be more beneficial for a long-term goal/solution. It is recommended that transdisciplinary research or multisectoral control approach including one health and/or eco health intervention strategy should be applied to combat the liver flukes and hence contribute to reduction of CCA in endemic areas.

Diagnosis of Human Trematode Infections

Digenetic trematodes form a major group of human parasites, affecting a large number of humans, especially in endemic foci. Over 100 species have been reported infecting humans, including blood, lung, liver and intestinal parasites. Traditionally, trematode infections have been diagnosed by parasitological methods based on the detection and the identification of eggs in different clinical samples. However, this is complicated due to the morphological similarity between eggs of different trematode species and other factors such as lack of sensitivity or ectopic locations of the parasites. Moreover, the problem is currently aggravated by migratory flows, international travel, international trade of foods and changes in alimentary habits. Although efforts have been made for the development of immunological and molecular techniques, the detection of eggs through parasitological techniques remains as the gold standard for the diagnosis of trematodiases. In the present chapter, we review the current status of knowledge on diagnostic techniques used when examining feces, urine, and sputum and also analyze the most relevant characteristics used to identify eggs with a quick key for the identification of eggs.

A rapid and visual detection assay for Clonorchis sinensis based on recombinase polymerase amplification and lateral flow dipstick

BACKGROUND

Fish-borne zoonotic clonorchiasis, caused by Clonorchis sinensis, is an emerging public health problem in several countries with more than 15 million people infected globally. However, a lack of accurate point-of-care (POC) diagnostic tests in resource-limited areas is still a critical barrier to effective treatment and control of clonorchiasis. The development of the recombinase polymerase amplification(RPA) assay, a POC diagnostic test based on the amplification of pathogen DNA, has provided a new, simple and inexpensive tool for disease detection with high sensitivity and specificity.

METHODS

A novel RPA method was developed based on specific primers and probes, and combined with the dipstick, to allow for the rapid and intuitive detection of C. sinensis through the amplification of the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene. The lower limit of detection for the combined RPA/lateral flow dipstick (RPA-LFD) assay was evaluated using dilutions of the target DNA sequence. Cross-reactivity was evaluated using genomic DNA from 10 additional control parasites. Forty human clinical stool samples were tested to verify its performance.

RESULTS

The evaluated primers designed from the C. sinensis COX1 region can be used to detect adult worms, metacercariae, and eggs at 39 °C within 20 min, and the results can be visually observed using the LFD. The detection limit of pathogen genomic DNA was as low as 10 fg, and the number of metacercaria(e) in fish and egg(s) in faeces were both as low as one. This improved the sensitivity of low-infection detection tremendously. The test is species-specific, and no other related control parasites were detected. In human stool samples with eggs per gram (EPG) > 50, the RPA-LFD assay was performed consistent with conventional Kato-Katz (KK) and PCR methods.

CONCLUSION

The established RPA-LFD assay provides a powerful tool for the diagnosis and epidemiological survey of C. sinensis from human and animal samples, and has important implications for the effective control of clonorchiasis.

Clonorchis sinensis granulin promotes malignant transformation of human intrahepatic biliary epithelial cells through interaction with M2 macrophages via regulation of STAT3 phosphorylation and the MEK/ERK pathway

BACKGROUND

Clonorchis sinensis granulin (CsGRN), a component of the excretory/secretory products of this species, is a multifunctional growth factor that can promote the metastasis of cholangiocarcinoma cells. However, the effect of CsGRN on human intrahepatic biliary epithelial cells (HIBECs) is unclear. Here, we investigated the effect of CsGRN on the malignant transformation of HIBECs and its possible underlying mechanism.

METHODS

The malignant transformation phenotypes of HIBECs after CsGRN treatment were estimated by EdU-488 incorporation assay, colony formation assay, wound-healing assay, Transwell assay and western blot. The biliary damage of CsGRN-treated mice was detected by western blot, immunohistochemical staining and hematoxylin and eosin staining. The phenotypes of the macrophages [human monocytic leukemia cell line (THP-1)] were analyzed by flow cytometry, immunofluorescence and immunohistochemistry, both in vitro and in vivo. A co-culture system was developed to explore the interaction between THP-1 and HIBECs in CsGRN-containing medium. Enzyme-linked immunosorbent assay and western blot were used to detected the activation of interleukin 6 (IL-6), phosphorylated signal transducer and activator of transcription 3 (p-STAT3) and the mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway. An inhibitor of the MEK/ERK pathway, PD98059, was used to determine whether this pathway is involved in CsGRN-mediated cell interactions as well as in STAT3 phosphorylation and malignant transformation of HIBECs.

RESULTS

Excessive hyperplasia and abnormal proliferation of HIBECs, enhanced secretion of hepatic pro-inflammatory cytokines and chemokines, as well as biliary damage, were observed in vitro and in vivo after treatment with CsGRN. The expression of the markers of M2 macrophages significantly increased in CsGRN-treated THP-1 cells and biliary duct tissues compared with the controls. Moreover, following treatment with CsGRN, the HIBECs underwent malignant transformation in the THP-1-HIBECs co-culture group. In addition, high expression of IL-6 was observed in the CsGRN-treated co-culture media, which activated the phosphorylation of STAT3, JAK2, MEK and ERK. However, treatment with an inhibitor of the MEK/ERK pathway, PD98059, decreased expression of p-STAT3 in CsGRN-treated HIBECs and further repressed the malignant transformation of HIBECs.

CONCLUSIONS

Our results demonstrated that, by inducing the M2-type polarization of macrophages and activating the IL-6/JAK2/STAT3 and MEK/ERK pathways in HIBECs, CsGRN promoted the malignant transformation of the latter.

Updated epidemiology of gastrointestinal cancers in East Asia

Globally, gastrointestinal cancers represent more than one-fourth of all cancer incidence and one-third of cancer-related mortality. Although there has been much progress in screening colorectal cancer, the prognosis of other gastrointestinal cancers tends to be poor. The highest burden of gastrointestinal cancers, including stomach, liver, oesophageal and gallbladder cancers, was observed in regions in East Asia. The increasing burden of gastrointestinal cancers in East Asian regions is related to population growth, ageing and the westernization of lifestyle habits in this region. Furthermore, the rising incidence of young-onset colorectal cancer is an emerging trend in East Asia. This Review provides a comprehensive and updated summary of the epidemiology of gastrointestinal cancers in East Asia, with emphasis on comparing their epidemiology in East Asia with that in Western regions, and highlights the major risk factors and implications for prevention. Overall, to optimally reduce the disease burden incurred by gastrointestinal cancers in East Asian regions, a concerted effort will be needed to modify unhealthy lifestyles, promote vaccination against the hepatitis virus, control Helicobacter pylori, liver fluke and hepatitis virus infections, increase the uptake rate of colorectal cancer screening, enhance detection of early cancers and their precursors, and improve cancer survivorship through an organized rehabilitation programme.

A systematic study on 33 gallbladder stones resembling adult Clonorchis sinensis worms

Limited studies provide direct evidence of Clonorchis sinensis adults in the early stage of gallbladder stone formation. Our current research systematically studied 33 gallbladder stones resembling adult worms and shed light on the definite connection of C. sinensis infection with concomitant cholelithiasis. A total of 33 gallbladder stones resembling adult C. sinensis worms were systematically analysed. Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray energy spectrometry were used to analyse the composition and microstructure. Meanwhile, a histopathological examination of the stone was carried out. The 33 gallbladder stones resembling adult C. sinensis worms included nine calcium carbonate (CaCO₃) stones, 12 bilirubinate stones and 12 mixed stones. Clonorchis sinensis eggs were found in 30 cases, including all CaCO₃ and mixed stones. Parasite tissues were detected in 12 cases, which were mainly CaCO₃ stones or bilirubinate-CaCO₃ mixed stones. The outer layer of stones was wrapped with 12.88% calcium salt, as revealed by X-ray energy spectrometry, while surprisingly, many C. sinensis eggs were found in the inner part of these stones. Based on our current findings, we concluded that calcification and packaging occurred after C. sinensis adult entrance into the gallbladder, subsequently leading to the early formation of CaCO₃ or bilirubinate-CaCO₃ mixed gallbladder stones. This discovery highlights definite evidence for C. sinensis infection causing gallbladder stones.

Long-Term Trend Analysis of Major Human Helminth Infections - Guangdong Province, China, 1988-2021

INTRODUCTION

Although helminth infections threaten millions of people worldwide, the spatiotemporal characteristics remain unclear across China. This study systematically describes the spatiotemporal changes of major human helminth infections and their epidemiological characteristics from 1988 to 2021 in Guangdong Province, China.

METHODS

The survey data in Guangdong Province were primarily obtained from 3 national surveys implemented during 1988-1992, 2001-2004, and 2014-2016, respectively, and from the China Information System for Disease Control and Prevention during 2019-2021. A modified Kato-Katz technique was used to detect parasite eggs in collected fecal samples.

RESULTS

The overall standardized infection rates (SIRs) of any soil-transmitted helminths (STH) and Clonorchis sinensis decreased from 65.27% during 1988-1992 to 4.23% during 2019-2021. In particular, the SIRs of STH had even more of a decrease, from 64.41% during 1988-1992 to 0.31% during 2019-2021. The SIRs of Clonorchis sinensis in the 4 surveys were 2.40%, 12.17%, 5.20%, and 3.93%, respectively. This study observed different permutations of gender, age, occupation, and education level on the SIRs of helminths.

CONCLUSIONS

The infection rate of STH has substantially decreased. However, the infection rate of Clonorchis sinensis has had fewer changes, and it has become the dominant helminth.

Differences in the secretory exosomes of Clonorchis sinensis adults at different incubation times

Exosomes are small membrane vesicles of endocytic origin and widely involved in a variety of physiological and pathological conditions. Exosome-like vesicles (ELVs) have been identified to mediate the parasite-host interactions and communication. Thus, increased knowledge of C. sinensis ELVs could provide insights into parasite-host interactions. In this experiment, ELVs was purified by ultracentrifugation from the culture medium of C. sinensis adults in vitro incubated for 24 h and 48 h, respectively. Transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) confirmed that the purified vesicles which ranged from 30 to 150 nm in size were present in the culture medium. Small RNA high-throughput sequencing analysis identified 51 miRNAs, including 37 known C. sinensis miRNAs, 3 novel C. sinensis miRNAs and 11 rat miRNAs. The sequencing data were validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The biological function of targets of known C. sinensis miRNAs were proved to associated with signal transduction, infectious diseases and the immune system. Further, 15 miRNAs were classified as differentially expressed in the 24h-ELVs compared to the 48h-ELVs. We found that the numbers and expression levels of most miRNAs from 24h-ELVs were more and higer than 48h-ELVs'. Our work provides important data for understanding the molecular mechanisms underlying the pathogenesis of C. sinensis adults ELVs.

Status of Helminthic Infections in Residents around River Basins in the Republic of Korea for 10 Years (2011-2020)

The positive rate of Clonorchis sinensis is the highest among intestinal parasites in the Republic of Korea (Korea). More than 1.2 million people were at risk of C. sinensis infection in Korea in 2012. An intensive control program is being implemented for residents of the 5 major river basins to reduce helminthic infections, including C. sinensis infection. This study evaluated the continuous intensive control program for parasitic diseases including clonorchiasis in areas near the 5 major river basins in Korea over the past 10 years (2011–2020). A total of 335,020 fecal samples (one sample per resident) prepared by the modified sedimentation technic were microscopically examined. Those who expelled helminth eggs were treated with anthelmintics through local health centers and re-examined 3 months later. The overall positive rate of helminths egg was 7.1%. The annual positive rates were dramatically decreased from 14.4% (2011) to 5.9% (2020). The egg positive rate was highest in C. sinensis (5.3%), followed by heterophyid flukes (1.5%) and Trichuris trichiura (0.2%). The prevalence of C. sinensis was significantly higher in males (7.6%) than in females (3.7%), and the highest in the 50–59 years (7.0%) age group. Our results are beneficial to establish prevention and control policies against helminthiases including clonorchiasis in endemic areas in this country.

Metabolome alterations in Clonorchis sinensis after treatment with tribendimidine and praziquante in vivo

Tribendimidine (TBD) is a broad-spectrum anthelmintic drug that is also significantly effective in treating clonorchiasis. In this study, the altered metabolomes of Clonorchis sinensis (C. sinensis) in rats after TBD administration were quantified by using ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) to explore the possible active sites of TBD against clonorchiasis through altered metabolites and metabolic pathway analysis, and the results are expected to provide a target for the future design of anti-Clonorchis sinensis drugs. The worm burden reduction rate and scanning electron microscopy demonstrated that praziquantel (PZQ, positive control drug) and TBD had significant effects on C. sinensis in rats after treatment at a single dose of 200 mg/kg for 24 h. For the MS-based metabolomic analysis, a total of 173 standard metabolites (126 amino acids, 10 phospholipids and 37 fatty acids) were utilized as a reference metabolite database for metabolome identification. In total, 32 amino acids, 71 phospholipids and 27 fatty acids were detected in the C. sinensis of each group. Among these metabolites, 10 amino acids were significantly decreased in both drug-treated groups. Four lysophosphatidyl cholines (LPCs), six lysophosphatidyl ethanolamines (LPEs) and one phosphatidyl inositol (PI) were significantly increased after treatment with TBD. There were no significant changes in fatty acids among the control group and the two drug-treated groups. The results indicated that TBD administration caused a decrease in amino acids involved in the metabolic pathways of energy consumption and an increase in lysophospholipids, which are the hydrolysis products of phospholipase2 (PLA2) in the phospholipid metabolic pathways. The increased lysophospholipid content can destroy the cell membrane, increase membrane permeability, and even cause exposure to internal antigens that can be attacked by host antibodies. Perhaps the destroyed membrane, the exposed internal antigens and the consumed energy are the cause of the damage and death of C. sinensis after TBD administration. This is an interesting problem that can be examined in future research.

General overview of the current status of human foodborne trematodiasis

Foodborne trematodes (FBT) of public health significance include liver flukes (Clonorchis sinensis, Opisthorchis viverrini, O. felineus, Fasciola hepatica and F. gigantica), lung flukes (Paragonimus westermani and several other Paragonimus spp.) and intestinal flukes, which include heterophyids (Metagonimus yokogawai, Heterophyes nocens and Haplorchis taichui), echinostomes (Echinostoma revolutum, Isthmiophora hortensis, Echinochasmus japonicus and Artyfechinostomum malayanum) and miscellaneous species, including Fasciolopsis buski and Gymnophalloides seoi. These trematode infections are distributed worldwide but occur most commonly in Asia. The global burden of FBT diseases has been estimated at about 80 million, however, this seems to be a considerable underestimate. Their life cycle involves a molluscan first intermediate host, and a second intermediate host, including freshwater fish, crustaceans, aquatic vegetables and freshwater or brackish water gastropods and bivalves. The mode of human infection is the consumption of the second intermediate host under raw or improperly cooked conditions. The major pathogenesis of C. sinensis and Opisthorchis spp. infection includes inflammation of the bile duct which leads to cholangitis and cholecystitis, and in a substantial number of patients, serious complications, such as liver cirrhosis and cholangiocarcinoma, may develop. In lung fluke infections, cough, bloody sputum and bronchiectasis are the most common clinical manifestations. However, lung flukes often migrate to extrapulmonary sites, including the brain, spinal cord, skin, subcutaneous tissues and abdominal organs. Intestinal flukes can induce inflammation in the intestinal mucosa, and they may at times undergo extraintestinal migration, in particular, in immunocompromised patients. In order to control FBT infections, eating foods after proper cooking is strongly recommended.

Clonorchis sinensis Granulin Promotes Malignant Transformation of Hepatocyte Through EGFR-Mediated RAS/MAPK/ERK and PI3K/Akt Signaling Pathways

The biological functions of growth factor, such as granulins, have been explored in parasites, and we elucidated that Clonorchis sinensis granulin (CsGRN) promoted the metastasis of hepatocellular carcinoma in our previous study. However, it is still unclear for the malignant transformation role of CsGRN in normal human hepatocytes. In this study, by transfecting pEGFP-C1-CsGRN eukaryotic expression plasmid, a cell line with stable overexpression of CsGRN in normal hepatocyte (LO2-GRN cells) was constructed. The effects on cell proliferation were detected by carrying out cell counting kit-8 (CCK8) assay and colony formation assay. Additionally, we conducted flow cytometry analysis to determine whether the proliferation of CsGRN was due to cell cycle arrest. Subsequently, the migration ability and the invasion ability of LO2-GRN cells were evaluated through wound-healing assay and transwell assay. Meanwhile, the levels of the markers of RAS/MAPK/ERK and PI3K/Akt signaling pathways activation in LO2-GRN cells were assessed by quantitative RT-PCR and Western blot. Our results indicated that CsGRN promoted the proliferation of LO2 cells by regulating the expression of cell-cycle-related genes. Moreover, the overexpression of CsGRN regulates malignant metastasis of liver cells by inducing the upregulation of epithelial-mesenchymal transition (EMT) marker proteins. Furthermore, both mRNA and protein expression levels of p-EGFR, RAS, p-ERK, p-AKT, p-PI3K, and p-braf have been enhanced by CsGRN. These results showed that CsGRN promoted the malignant transformation of hepatocytes by regulating epidermal growth factor receptor (EGFR)-mediated RAS/MAPK/ERK and PI3K/Akt signaling pathways, which suggested that CsGRN could serve as a novel oncoprotein during Clonorchis sinensis-associated malignant transformation of hepatocytes.

Iberian Distribution of the Freshwater Snail Genus Bithynia Leach, 1818 (Mollusca: Truncatelloidea), Vector of Opisthorchiasis and Metorchiasis

BACKGROUND

Opisthorchis felineus and Metorchis bilis are trematodes that cause opisthorchiasis and metorchiasis, respectively. The freshwater snails Bithynia hispanica and B. tentaculata are the respective intermediate hosts for these parasites in the Iberian Peninsula, where both parasites are present.

METHODS

To study the distribution of these snail species, an exhaustive literature review and revision of museum collections was performed.

RESULTS

A total of 370 localities were compiled and mapped. B. tentaculata were found throughout the Iberian Peninsula, both in Spain and Portugal, while B. hispanica was found only in the Mediterranean coast of Spain.

CONCLUSION

Knowing the distribution of the Bithynia species found in the Iberian Peninsula is highlighted in terms of public health, as the presence of the snail is related to the presence of the disease and can be used as a tool to face future outbreaks.

Tissue Pathogens and Cancers: A Review of Commonly Seen Manifestations in Histo- and Cytopathology

Tissue pathogens are commonly encountered in histopathology and cytology practice, where they can present as either benign mimickers of malignancy or true malignancies. The aim of this review is to provide a timely synthesis of our understanding of these tissue pathogens, with an emphasis on pertinent diagnostic conundrums associated with the benign mimickers of malignancy that can be seen with viral infections and those which manifest as granulomas. The oncogenic pathogens, including viruses, bacteria, and parasites, are then discussed with relationship to their associated malignancies. Although not exhaustive, the epidemiology, clinical manifestations, pathogenesis, and histological findings are included, along with a short review of emerging therapies.

Novel mechanism of hepatobiliary system damage and immunoglobulin G4 elevation caused by Clonorchis sinensis infection

Clonorchis sinensis infection is still a major public health problem. It is estimated that more than 15 million people worldwide are infected, especially in Northeast China, Taiwan, South Korea, and North Vietnam. The detection of Clonorchis sinensis eggs in feces and bile is still the only gold standard for the diagnosis of Clonorchis sinensis infection, and new detection methods are needed to improve the detection rate. After Clonorchis sinensis invades the human body, it mainly parasitizes the hepatobiliary tract. Therefore, it is closely related to hepatobiliary diseases such as cholangitis, bile duct stones, liver fibrosis, and cholangiocarcinoma. The increase in immunoglobulin G4 (IgG4) caused by Clonorchis sinensis infection is rare and there are few reports about the relevant mechanism. It may be related to the inflammatory factors interleukin (IL)-4, IL-10, and IL-13 produced by human phagocytes, T cells, B cells, and other immune cells in the process of resisting the invasion of Clonorchis sinensis. However, this finding still needs further clarification and confirmation. This article reviews the epidemiology, clinical manifestations, serology, imaging, pathogenic mechanism, and control measures of Clonorchis sinensis infection to help establish the diagnostic process for Clonorchis sinensis. We report novel mechanisms of IgG4 elevation due to Clonorchis sinensis infection to provide more experience and a theoretical basis for clinical diagnosis and treatment of this infection.

Microbiome in human cancers

A microbiome is defined as the aggregate of all microbiota that reside in human digestive system and other tissues. This microbiota includes viruses, bacteria, fungi that live in various human organs and tissues like stomach, guts, oesophagus, mouth cavity, urinary tract, vagina, lungs, and skin. Almost 20 % of malignant cancers worldwide are related to microbial infections including bacteria, parasites, and viruses. The human body is constantly being attacked by microbes during its lifetime and microbial pathogens that have tumorigenic effects in 15-20 % of reported cancer cases. Recent scientific advances and the discovery of the effect of microbes on cancer as a pathogen or as a drug have significantly contributed to our understanding of the complex relationship between microbiome and cancer. The aim of this study is to overview some microbiomes that reside in the human body and their roles in cancer.

Parasitic Infections of the Gastrointestinal Track and Liver

Parasites have coevolved with humans. Several of them colonize the human body and establish a symbiotic relationship. Other parasites cause severe and lethal diseases. Prevalence of parasitic infections is decreased in highly industrialized countries, largely due to enforced hygienic practices. In contrast, parasites cause significant morbidity and mortality in parts of the world with barriers to effective public hygiene. Some parasites have emerged as potent pathogens in specific patient populations, such as immune suppressed individuals, regardless of sanitation. This article reviews common parasites encountered in clinical practice and, in the setting of host-parasite symbiosis, discusses their immune regulatory role.

The NF-κB signalling pathway and TM7SF3 contribute to liver fibrosis caused by secreted phospholipase A2 of Clonorchis sinensis

Background

The NF-κB signalling pathway has been reported to be related to liver fibrosis, and we investigated whether the NF-κB signalling pathway is involved in liver fibrosis caused by secreted phospholipase A2 of Clonorchis sinensis (CssPLA2). Furthermore, expression of the receptor of CssPLA2 on the cell surface of hepatic stellate cells (HSCs) may greatly contribute to liver fibrosis.

Methods

CssPLA2 was administered to BALB/c mice by abdominal injection. The levels of markers of NF-κB signalling pathway activation in mouse liver tissue were measured by quantitative RT-PCR, ELISA and western blot. Additionally, HSCs were incubated with CssPLA2, and an NF-κB signalling inhibitor (BAY 11-7082) was applied to test whether the NF-κB signalling pathway plays a role in the effect of CssPLA2. Then, the interaction between CssPLA2 and its receptor transmembrane 7 superfamily member 3 (TM7SF3) was confirmed by co-immunoprecipitation (co-IP) and GST pull-down. To determine how TM7SF3 influences the ability of CssPLA2 to cause liver fibrosis, a TM7SF3 antibody was used to block TM7SF3.

Results

The levels of the NF-ΚB signalling pathway activation markers TNF-α, IL-1β and phospho-p65 were increased by CssPLA2 in the context of liver fibrosis. In addition, the interaction between TM7SF3 and CssPLA2 was confirmed by co-IP and GST pull-down. When TM7SF3 was blocked by an antibody targeting 1–295 amino acids of TM7SF3, activation of HSCs caused by CssPLA2 was alleviated.

Conclusions

The NF-ΚB signalling pathway is involved in the activation of HSCs by CssPLA2. TM7SF3, the receptor of CssPLA2, plays important roles in liver fibrosis caused by CssPLA2.

Intraductal papillary neoplasm of the bile duct - A comprehensive review

BACKGROUND

Intraductal papillary neoplasm of the bile ducts is a rare tumor type. Management decisions are currently based upon a small case series. The authors have large own experience with IPNB.

OBJECTIVE

The review aims at reporting on clinicopathological features of IPNB in order to provide guidance for management.

METHODS

We searched PubMed, Medline, Microsoft Academic and Embase databases to identify studies of relevance. The analysis of own experience was also included.

RESULTS

We analyzed 59 retrospective series and 25 cases from authors' clinical experience. The main sign was jaundice and cholangitis, 33% and 48%, respectively. CT's were performed in 63-76% and MR in 40-56%. Intraductal mass was found in 31-32% and duct dilatation in 27-30%. Endoscopic Retrograde Cholangio-Pancreatography (ERCP) was performed in 48-62%. IPNB with invasive carcinoma was found in 35.7-60% and IPNB with intraepithelial neoplasia in 36-60%. Histopathological confirmation before surgery was rare. The main treatment of IPNB is resection, in our material, both, hepatectomy and hepatectomy plus bile duct resections were performed in 40% of patients. The percentage of postoperative complications was 20%. The 5-year survival rate of all IPNB's patients was 53.6%; in patients with associated invasive carcinoma - 22.2% and without invasive carcinoma - 100% (p ​= ​0.001).

CONCLUSIONS

Early surgery is advisable for radiologically suspected IPNB. The results of treatment depend on histopathology. They are worse at intraductal invasive carcinoma than at neoplasm with neoplasia.

TLR4 Deficiency Exacerbates Biliary Injuries and Peribiliary Fibrosis Caused by Clonorchis sinensis in a Resistant Mouse Strain

Mice with different genetic backgrounds have various susceptibilities to infection with Clonorchis sinensis, although the mechanisms underlying are largely unknown. Toll-like receptor 4 (TLR4) as one of the most important pattern recognition receptors (PPRs) is essential for the invasion, survival, pathogenesis, and elimination of worms. The roles played by TLR4 in C. sinensis infection may vary due to the different genetic backgrounds of mice. In the present study, a relatively resistant mouse strain-C57BL/10 to C. sinensis was used for investigation on the possible roles of TLR4 in the biliary injuries and peribiliary fibrosis. TLR4 wild type (TLR4^wild) and TLR4 defective (TLR4^def) mice were orally infected with 45 metacercariae of C. sinensis, and all C. sinensis-infected mice and non-infected groups were anesthetized on day 28 post-infection. The liver and serum from each mouse were collected for assessment of the biliary injuries and biliary fibrosis. Meanwhile, hepatic leukocytes were isolated and detected for the activation of M1 or M2 macrophage using flow cytometry. The hepatic type 1 immune response and type 2 immune responses -relative molecules were also evaluated using ELISA and quantitative PCR. The data showed that TLR4^def aggravated liver inflammatory cell infiltrations, bile duct proliferation, biliary and hepatocellular injuries, and ECM deposition in C. sinensis-infected mice, compared with TLR4^wild mice when they were intragastrically administered with the same amounts of C. sinensis metacercaria. Furthermore, the M2-like macrophages and type 2 immune responses were significantly predominant induced in TLR4^def mice, compared with that of TLR4^wild mice following C. sinensis infection. But the type 1 immune response were significantly decreased in TLR4^def mice, compared with TLR4^wild mice after C. sinensis infection. These data demonstrate that TLR4 deficiency exacerbates biliary injuries and peribiliary fibrosis caused by C. sinensis in C57BL/10 strain mice, which is contributed by augments of type 2 immune responses and decrease pro-inflammatory responses.

Serodiagnostic antigens of Clonorchis sinensis identified and evaluated by high-throughput proteogenomics

Clonorchiasis caused by Clonorchis sinensis is endemic in East Asia; approximately 15 million people have been infected thus far. To diagnose the infection, serodiagnostic tests with excellent functionality should be performed. First, 607 expressed sequence tags encoding polypeptides with a secretory signal were expressed into recombinant proteins using an in vitro translation system. By protein array-based screening using C. sinensis-infected sera, 18 antigen candidate proteins were selected and assayed for cross-reactivity against Opisthorchis viverrini-infected sera. Of the six antigenic proteins selected, four were synthesized on large scale in vitro and evaluated for antigenicity against the flukes-infected human sera using ELISA. CsAg17 antigen showed the highest sensitivity (77.1%) and specificity (71.2%). The sensitivity and specificity of the bacterially produced CsAg17-28GST fusion antigen was similar to those of CsAg17 antigen. CsAg17 antigen can be used to develop point-of-care serodiagnostic tests for clonorchiasis.

Human clonorchiasis is a parasitic disease caused by the Chinese liver fluke, Clonorchis sinensis. Humans are infected through eating raw freshwater fishes carrying C. sinensis metacercariae, the encysted larvae. They excyst in the duodenum, move into the liver via bile duct and grow to adult worms. Excretory-secretory products of the worm damage the liver causing various inflammatory pathological changes and may lead to bile duct cancer. Although there exists an anthelmintic choice praziquantel to kill the fluke, emphasis is placed on early diagnosis and prevention before the infection becomes disease. Microscopic stool examination is the standard diagnostic method but is cumbersome and time consuming. Blood serum antibodies from clonorchiasis patients could provide a simple and fast diagnosis. However, antibody detecting diagnostics developed so far have a low specificity and sensitivity. In the present study we selected 607 antigenic candidate proteins from the genomic database and synthesized them through an integrated high-throughput proteogenomic tools. We identified several antigenic proteins and evaluated their diagnostic potential for clonorchiasis. One of them, CsAg17, showed a high sensitivity and specificity. This antigen deserves development of point-of-care serodiagnostics for C. sinensis infections.

Foodborne zoonotic parasites of the family Opisthorchiidae

Several foodborne zoonotic trematodes of the family Opisthorchiidae have been reported to infect people, specifically two genera, Clonorchis and Opisthorchis. Three species Clonorchis sinensis, Opisthorchis felineus and Opisthorchis viverrini are the most extensivley studied of the Opisthorchiidae. At least 680 million people worldwide are at risk of infection of these liver flukes through the consumption of raw or partially cooked freshwater cyprinid fish. An estimated 45 million people in Europe and Asia are currently infected with these liver flukes. Of these, the 35 million are infected with C. sinensis mainly in China, 10 million with O. viverrini in Southeast Asia, and 1.2 million with O. felineus in Eastern Europe and Russia. These liver flukes have been proven to be causative agents of bile duct cancer or cholangiocarcinoma (CCA). A multidisciplinary program should be implemented involving comprehensive research on molecular genetics, diagnosis, treatment, prevention, as well as educational and control programs should progressively be introduced and applied in endemic regions of O. viverrini, O. felineus and C. sinensis throughout their ranges, hence, opisthorchiasis and clonorchiasis free communities can be realised globally.

Prevalence of Clonorchis sinensis infection in fish in South-East Asia: A systematic review and meta-analysis

Clonorchis sinensis, an important fish-borne zoonotic trematode, is widely distributed in South-East Asia, especially in China. Infections from human and animal reservoir hosts occur due to the consumption of raw or undercooked fish with C. sinensis metacercariae. This study aimed to evaluate the prevalence of C. sinensis metacercariae in fish in South-East Asia via systematic review and meta-analysis. We searched PubMed, ScienceDirect, China National Knowledge Infrastructure, Wanfang and Chongqing VIP databases for studies published between 1976 and 2020 that are related to the prevalence of C. sinensis metacercariae in fish. Studies were screened with keywords based on inclusion and exclusion criteria. Seventy-one eligible articles were identified, covering three countries: China, Korea and Vietnam. The pooled prevalence of C. sinensis metacercariae in fish from South-East Asia was 30.5%, with 35.1% in China, 29.7% in Korea and 8.4% in Vietnam. In subgroup analyses of climate, season, water source and publication date, the highest prevalence was identified in the Dwb climate type (43.3%), summer (70.2%), river (34.5%) and pre-2001 publications (38.9%), respectively. In comparison, the lowest prevalence was found in the Dfa climate type (14.5%), winter (19.5%), lake (8.0%) and post-2001 publications (23.8%). Meta-regression results indicated that country (p = .009), the published time (p = .035) and water source subgroups (p = .003) may be the source of heterogeneity. Overall, our study indicates that a high prevalence of C. sinensis infections occurs in fish in China, Korea and Vietnam, illuminating a significant public health concern in these countries.

Prevalence and risk factors associated with Clonorchis sinensis infections in rural communities in northern Vietnam

BACKGROUND

Clonorchiasis, caused by the fish-borne trematode Clonorchis sinensis, is a neglected tropical disease and a public health issue in endemic countries. In Vietnam, an in-depth analysis of risk factors for the condition is missing up to now. This study aimed to determine the prevalence of C. sinensis infection and associated risk factors in rural communities in northern Vietnam.

METHODOLOGY/PRINCIPAL FINDINGS

A cross-sectional survey was conducted in 4 communes in Yen Bai and Thanh Hoa provinces where clonorchiasis is known to be present and raw fish consumption is a common. Using a simple random sampling approach, stool was collected from 841 participants over 6 years old for coprological examination, and a questionnaire measured knowledge, attitudes, and practices with regard to clonorchiasis in 757 participants over 15 years old. Univariable and multivariable logistic regression models were run to identify risk factors for infection with C. sinensis. The overall prevalence of C. sinensis infection was 40.4%, with commune prevalences ranging between 26.5% and 53.3%. In the final model, males were significantly more likely to be infected with C. sinensis (OR 2.00; 95% CI 1.31-3.05). Recent (i.e. last year) consumption of raw fish (OR 8.00, 95% CI 4.78-13.36), low education level (OR 5.57; 95% CI 2.37-13.07), lack of treatment (OR 1.82, 95% CI 1.15-2.89), being between 19 to 39 years old (OR 6.46; 95% CI 1.25-33.37), and the presence of an unhygienic toilet (OR 2.74, 95% CI 1.53-4.92) were significantly associated with C. sinensis infection.

CONCLUSION/SIGNIFICANCE

This study demonstrated a high prevalence of C. sinensis infection in rural communities in northern Vietnam. Thus, control measures including, mass drug administration for those communes should be applied to reduce the prevalence. Moreover, specific health education activities should be developed for risk groups in C. sinensis endemic areas.

High endemicity of Clonorchis sinensis infection in Binyang County, southern China

High-intensity clonorchiasis infection is associated with serious outcomes, including cancer. Understanding the infection intensity of Clonorchis sinensis and its risk factors in local endemic regions could facilitate effective control measures. In a county located in a highly endemic area in Guangxi Province, P. R. China, local residents were randomly enrolled in the study; helminth egg examinations were performed with the Kato-Katz method, and the intensity of infection was identified as mild, moderate or heavy. Knowledge, attitudes, and high-risk behaviours were investigated among those infected with Clonorchis sinensis. A total of 2521 local residents participated in this study, and the Clonorchis sinensis-positive proportion was 28.9% (728 persons). Among the infected persons, the percentages of mild, moderate and heavy infections were 66.2%, 28.4% and 5.4%, respectively. Males experienced a higher proportion of moderate and heavy infections (37.5%) than females (18.1%) (p<0.05). The highest infection proportion among the different levels of infection intensity was identified among persons aged 30-59 years (15.7% for moderate and heavy infections). Among the 509 persons who reported eating raw fish, 302 persons (59.3%) had eaten raw fresh fish for more than 10 years, and 131 (25.7%) persons ate raw fish ≥12 times a year. Multivariate logistic regression revealed that eating raw fish 12-50 times in the last year (adjusted odds ratio [aOR] = 1.74, 95%CI: 1.09-2.80) and eating raw fish >50 times in the last year (aOR = 2.89, 95%CI: 1.20-7.50) were risk factors for high-intensity infections (moderate and heavy). The overall infection proportion was high in the study area, with a large group of residents experiencing high-intensity infections. High frequency of raw fish consumption was associated with high-intensity infections. Intervention strategies targeting people with a high frequency of raw fish consumption should be implemented to reduce the probability of severe consequences.

Clonorchis sinensis ESPs enhance the activation of hepatic stellate cells by a cross-talk of TLR4 and TGF-β/Smads signaling pathway

Excretory/Secretory products (ESPs) from Clonorchis sinensis-a fluke dwelling on the biliary ducts-promote the activation of hepatic stellate cells (HSCs) and lead to hepatic fibrosis ultimately, although the mechanisms that are responsible for CsESPs-induced activation of HSCs are largely unknown. In the present study, we investigated the underlying mechanism of TLR4 in the regulation of the activation of HSCs caused by CsESPs. We found that the expression of TLR4 was significantly increased in the HSCs with CsESPs for 24 h, compared to the control group. However, the activation of HSCs induced by CsESPs was inhibited by interfering with TGF-β/Smad pathway using a TGF-β receptor I inhibitor LY2157299, indicating that TGF-β induced signaling pathway was involved in CsESPs-caused the activation of HSCs. In addition, the activation of HSCs caused by CsESPs was remarkably inhibited by a TLR4 specific inhibitor (VIPER), and phosphorylation of Smad2/3 was significantly attenuated but the expression of the pseudoreceptor of TGF-β-type I receptor (BAMBI) was obviously increased when TLR4 signaling pathway was blocked. The results of the present study demonstrate that activation of HSCs caused by CsESPs is mediated by a cross-talk between TLR4 and TGF-β/Smads signaling pathway, and may provide a potential treatment strategy to interrupt the process of liver fibrosis caused by C. sinensis.

In vivo and in vitro studies using Clonorchis sinensis adult-derived total protein (CsTP) on cellular function and inflammatory effect in mouse and cell model

Clonorchis sinensis (C. sinensis) can induce a food-borne parasitic disease (clonorchiasis). Numerous studies have analyzed functional proteins, immunologic factors, pro-inflammatory cytokines, and cell signaling transduction that promote the development of clonorchiasis. In a previous study, it was shown that C. sinensis adult-derived total protein (CsTP) might be involved in the pathogenesis and development of liver fibrosis via bringing about Th2 immune response. In the present study, further investigation of CsTP on cellular function and inflammatory effect in vitro and in vivo has been elicited. CsTP induced inflammation and autophagy as evidenced by upregulation of TNF-α, IFN-γ, and autophagic markers LC3B and P62. Exposed to CsTP upregulated the antiapoptotic gene Bcl-2 expression, diminished the apoptosis induced by H₂O₂, but promoted the proliferation and migration of LX-2 cells in proper concentration range. Additionally, the protein levels of p-AKT and p-mTOR were repressed in response to CsTP, suggesting a correlation of blocking the activation of mTOR/AKT signaling pathway. These results revealed that CsTP might exacerbate hepatic pathological changes by regulating cell proliferation, apoptosis, autophagy, and inflammation in the liver and LX-2 cells. Some effects might be partially involved in the mTOR and AKT pathways.

Development of an Immunochromatographic Point-of-Care Test for Serodiagnosis of Opisthorchiasis and Clonorchiasis

Chronic infections with the food-borne liver flukes, Opisthorchis viverrini or Clonorchis sinensis, associate with cholangiocarcinoma, bile duct cancer, which generally has a poor prognosis. We have produced a rapid and simple immunochromatographic test (ICT) kit for the diagnosis of opisthorchiasis and clonorchiasis by the detection of IgG antibodies in human infection sera. Sera from volunteers with proven opisthorchiasis and several other parasitic diseases and from healthy controls were evaluated for the presence of liver fluke infection-specific antibodies using a preparation of excretory-secretory antigen from adult stage O. viverrini absorbed onto ICT strips. Diagnostic values were compared with an ELISA. The diagnostic sensitivity, specificity, and positive and negative predictive values of the ELISA were 100%, 98.3%, 97.9%, and 100%, whereas those for the ICT were 94.6%, 91.2%, 89.7%, and 95.4%, respectively. There was 91.7% concordance between the ICT with ELISA, and differences in performance between the tests were not statistically significant (P > 0.05). Twenty-seven of 30 (90%) of the clonorchiasis sera also were positive by ICT. This new ICT provides a facile, rapid test for point-of-care testing tool, which can be used at the bedside without the need for sophisticated equipment. Moreover, the ICT can be anticipated to supplement stool examination as a screening tool in the clinic for the diagnosis of opisthorchiasis and clonorchiasis, and in addition, it may be useful in screens of populations at risk of liver fluke infection-associated cholangiocarcinoma.

Surveillance of clonorchiasis in China in 2016

Clonorchiasis is an important food-borne parasitic disease in China, and infection with C. sinensis can cause hepatobiliary diseases. Comprehensive and systematic prevention and control of clonorchiasis requires the establishment of an effective surveillance. A total of 301 surveillance points were set up in 30 provinces across China in 2016, and 1000 people were selected by cluster sampling at each surveillance point annually for C. sinensis infection screening using Kato-Katz thick smear method. C. sinensis infection was detected in 6226 people following screening of 305081 people at the 301 surveillance points in 2016. Infection rate was 2.04%; with C. sinensis infection detected in 70 counties spread across 15 provinces, 89.37% of the infected people were distributed in Jilin, Heilongjiang, Guangdong and Guangxi provinces. Highest infection rate was observed in Da'an city, Jilin Province (49%). The national infection rate in male and female was 2.70% and 1.40% respectively. Infection rate between male and female was significantly different (P <0.01). Disease prevalence increases with age in both male and female, reaches peak in age group 40-49. Result obtained indicate that major C. sinensis endemic areas are distributed in the north and south of China, and areas with high prevalence are distributed along the river system at county level. Result, also, shows that middle-aged men are at high-risk of infection. These results suggest that surveillance activities should be sustained nationwide and highlight the need for an integrated approach to control C. sinensis transmission in regions with high disease prevalence in China.

The control of clonorchiasis in Guangdong province, southern China

Oriental liver fluke disease (clonorchiasis), caused by Clonorchis sinensis, is endemic in 81 counties in Guangdong province, China. This study was conducted following increasing lack of clonorchiasis awareness and increased consumption of raw freshwater fish and raw fish porridge at home and restaurants, which has been attributed to improved living standards in China, and is considered to have led to a higher C. sinensis infection rate in the country. A total of 61,517 individuals were investigated from 123 sites during a provincial survey in 1988, with average C. sinensis infection rate of 1.82% that increased to 4.08% (335/8217) in 1997. Higher infection rate was observed in adult men than women, with heavy infection rate in fishermen and businessmen because they have access and means to get raw fishes for consumption. Thus, clonorchiasis has become a serious public health problem in Guangdong province. Efforts targeting clonorchiasis prevention and control in Guangdong province started in the 1990s. These included carrying out large-scale surveys and chemotherapy in epidemic regions, research on promotion of environmental sanitation and methods for freshwater aquaculture. Establishment and promotion of clonorchiosis demonstration plots for comprehensive control measures, as well as the development of clonorchiasis-prevention community-out-patient clinics were initiated and their effectiveness was evaluated. However, there seem to be no obvious decline in the prevalence of C. sinensis with 4.90% (608/12,401) in 2015, at Guangdong province due to the people's habit of eating raw fishes in endemic areas. This has led to increasing calls to improve environmental sanitation in the aquaculture industry. It is, however, believed that control efforts on clonorchiosis in the province are at an early stage and require strengthening through the cooperation of different departments to work out effective strategies for sustainable field application of control mechanisms.

Surgical Infections in Low- and Middle-Income Countries: A Global Assessment of the Burden and Management Needs

Background: The burden of surgical infections in low- and middle-income countries (LMICs) remains poorly defined compared with high-income countries. Although there are common infections necessitating surgery prevalent across the world, such as appendicitis and peptic ulcer disease, other conditions are more localized geographically. To date, comprehensive assessment of the burden of surgically treatable infections or sequelae of surgical infections in LMICs is lacking. Methods: We reviewed the literature to define the burden of surgical infections in LMICs and characterize the needs and challenges of addressing this issue. Results: Surgical infections comprise a broad range of diseases including intra-abdominal, skin and soft tissue, and healthcare-associated infections and other infectious processes. Treatment of surgical infections requires a functional surgical ecosystem, microbiology services, and appropriate and effective antimicrobial therapy. Systems must be developed and maintained to evaluate screening, prevention, and treatment strategies. Solutions and interventions are proposed focusing on reducing the burden of disease, improving surveillance, strengthening antibiotic stewardship, and enhancing the management of surgical infections. Conclusions: Surgical infections constitute a large burden of disease globally. Challenges to management in LMICs include a shortage of trained personnel and material resources. The increasing rate of antimicrobial drug resistance, likely related to antibiotic misuse, adds to the challenges. Development of surveillance, infection prevention, and antimicrobial stewardship programs are initial steps forward. Education is critical and should begin early in training, be an active process, and be sustained through regular programs.

Acute shock caused by Clonorchis sinensis infection: a case report

Background

Clonorchiasis, caused by Clonorchis sinensis (C. sinensis) infection, is a serious food-borne zoonotic disease that is often asymptomatic or shows only mild symptoms, which leads to delayed treatment and chronic clonorchiasis and results in various complications, such as cholelithiasis, cholangitis, cholecystitis and cholangiocarcinoma. However, acute shock caused by C. sinensis infection has not been reported. Here, for the first time, we describe a fatal case of acute shock caused by C. sinensis infection.

Case presentation

A patient with a history of eating raw or undercooked freshwater fish was hospitalized with acute shock caused by severe abdominal pain. Physical examination suggested acute abdomen with severe abdominal pain and rigidity. Computed tomography (CT) detection indicated acute cholecystitis and cholelithiasis. After cholecystectomy, several liver flukes were found in the drainage tube. Furthermore, morphological analysis and polymerase chain reaction (PCR) identified the pathogen as C. sinensis. The liver gradually restored normal function after anthelmintic therapy with praziquantel.

Conclusions

In this fatal case, C. sinensis infection was the cause of acute shock, which is rarely found in the clinic environment. This report aims to increase awareness of the hazards and complications related to clonorchiasis. The PCR diagnosis method used in this report might be helpful in reducing the misdiagnosis of clonorchiasis and unnecessary cholecystectomy.

Association between eosinophil count and cholelithiasis among a population with Clonorchis sinensis infection in Foshan City, China

The association between eosinophil count and cholelithiasis among people with Clonorchis sinensis infection is still uncertain. We conducted a cross-sectional study to investigate the associations among Clonorchis sinensis infection, eosinophil count and cholelithiasis. The study included 4628 participants from January to December 2018. The levels of eosinophil count were divided into four groups according to the quartiles of eosinophil count. Spearman's rank correlation was performed to assess the association between eosinophil counts and Clonorchis sinensis egg counts. Multiple regression analysis was performed to evaluate the relationships among C. sinensis infection, eosinophil count and cholelithiasis after adjusting for three models. The prevalence of C. sinensis infection was 38.72% (1792/4628), and the prevalence of cholelithiasis was 6.03% (279/4628). The infection rate of C. sinensis was higher in the cholelithiasis group than in the non-cholelithiasis group (63.08% vs. 37.16%, P < 0.001). Significant differences were found among various eosinophil count quartiles for C. sinensis infection, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyltranspeptidase (γ-GT), triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), creatinine (CRE), blood urea nitrogen (BUN), uric acid (UA) and non-alcoholic fatty liver disease (NAFLD) (all P < 0.001). A significant positive correlation was found between eosinophil count and log-transformed C. sinensis egg count (r = 0.9477, P < 0.001). Multiple logistic regression analysis revealed that light and moderate intensities of C. sinensis infection were associated with cholelithiasis (P < 0.01 and P < 0.001, respectively), and C. sinensis infection with eosinophil count ranging from 0.05 to 0.5 × 109/l were associated with cholelithiasis (P < 0.05). In conclusion, our findings suggest that the light and moderate infections of C. sinensis with eosinophil count ranging from 0.05 to 0.5 × 109/l may be associated with a higher risk of cholelithiasis.

Diagnosis of Human Trematode Infections

Digenetic trematodes form a major group of human parasites, affecting a large number of humans, especially in endemic foci. Over 100 species have been reported infecting humans, including blood, lung, liver, and intestinal parasites. Traditionally, trematode infections have been diagnosed by parasitological methods based on the detection and the identification of eggs in different clinical samples. However, this is complicated due to the morphological similarity between eggs of different trematode species and other factors such as lack of sensitivity or ectopic locations of the parasites. Moreover, the problem is currently aggravated by migratory flows, international travel, international trade of foods, and changes in alimentary habits. Although efforts have been made for the development of immunological and molecular techniques, the detection of eggs through parasitological techniques remains as the gold standard for the diagnosis of trematodiases. In this chapter, we review the current status of knowledge on diagnostic techniques used when examining feces, urine, and sputum and also analyze the most relevant characteristics used to identify eggs with a quick key for the identification of eggs.

Cytokine Production in Cholangiocarcinoma Cells in Response to Clonorchis sinensis Excretory-Secretory Products and Their Putative Protein Components

Clonorchis sinensis is a carcinogenic human liver fluke that promotes hepatic inflammatory environments via direct contact or through their excretory-secretory products (ESPs), subsequently leading to cholangitis, periductal fibrosis, liver cirrhosis, and even cholangiocarcinoma (CCA). This study was conducted to examine the host inflammatory responses to C. sinensis ESPs and their putative protein components selected from C. sinensis expressed sequenced tag (EST) pool databases, including TGF-β receptor interacting protein 1(CsTRIP1), legumain (CsLeg), and growth factor binding protein 2 (CsGrb2). Treatment of CCA cells (HuCCT1) with the ESPs or bacterial recombinant C. sinensis proteins differentially promoted the secretion of proinflammatory cytokines (IL-1β, IL-6, and TNF-α) as well as anti-inflammatory cytokines (IL-10, TGF-β1, and TGF-β2) in a time-dependent manner. In particular, recombinant C. sinensis protein treatment resulted in increase (at maximum) of ~7-fold in TGF-β1, ~30-fold in TGF-β2, and ~3-fold in TNF-α compared with the increase produced by ESPs, indicating that CsTrip1, CsLeg, and CsGrb2 function as strong inducers for secretion of these cytokines in host cells. These results suggest that C. sinensis ESPs contribute to the immunopathological response in host cells, leading to clonorchiasis-associated hepatobiliary abnormalities of greater severity.

Chemotactic migration of newly excysted juvenile Clonorchis sinensis is suppressed by neuro-antagonists

The metacercariae of the Clonorchis sinensis liver fluke excyst in the duodenum of mammalian hosts, and the newly excysted juveniles (CsNEJs) migrate along the bile duct via bile chemotaxis. Cholic acid is a major component of bile that induces this migration. We investigated the neuronal control of chemotactic behavior of CsNEJs toward cholic acid. The migration of CsNEJs was strongly inhibited at sub-micromolar concentration by dopamine D1 (LE-300 and SKF-83566), D2 (spiramide, nemonapride, and sulpiride), and D3 (GR-103691 and NGB-2904) receptor antagonists, as well as a dopamine reuptake inhibitor (BTCP). Neuropeptides, FMRFamide, peptide YY, and neuropeptide Y were also potent inhibitors of chemotaxis. Meanwhile, serotonergic, glutamatergic, and cholinergic inhibitors did not affect chemotaxis, with the exception of fluoxetine and CNQX. Confocal immunofluorescence analysis indicated that dopaminergic and cholinergic neurons were colocalized in the somatic muscle tissues of adult C. sinensis. Our findings suggest that dopaminergic neurons and neuropeptides play a major role in the chemotactic migration of CsNEJs to bile, and their inhibitors or modulators could be utilized to prevent their migration from the bile duct.

A Clonorchiasis Case of a Leopard Cat, Prionailurus bengalensis euptilurus, Diagnosed by Ultrasonography and Egg Detection in Republic of Korea

A clonorchiasis case in a captive leopard cat, Prionailurus bengalensis euptilurus, was confirmed by ultrasonographic findings and egg morphologies found in the bile juice sample in the Korea. The leopard cat was introduced from the wild habitat of Gyeongsangnam-do, to Cheongju Zoo in Cheongju-si, Chungcheongbuk-do, Korea in August 2014. Physical examinations were basically performed for quarantine and check-up health. The cat was comparatively good in health except anorexia. The cyst-like bile duct dilation and the increased echogenicity of gall bladder wall and hepatic parenchyma were observed by ultrasonography. Ultrasound-guided needle biopsy was conducted for collecting bile juice and the specimens were observed under light microscope. The numerous small trematode eggs were detected in the bile juice sample of the light microscopy. The eggs were 25–33 (28±3) μm by 18–22 (20±1) μm in size and showed typical characteristics of Clonorchis sinensis egg, i.e., a dominantly developed operculum, shoulder rim and dust-like wrinkles in surface. To treat the liver fluke infection, 20 mg/kg of praziquantel was orally administered only once to the case. Follow-up studies including fecal examinations were conducted during 2 years after treatment. But no more eggs were detected from the case. In the present study, we described the first clonorchiasis case of leopard cat, which was confirmed by ultrasonographic findings and egg morphologies from the bile juice sample in Korea.

Connexin 43 plays an important role in the transformation of cholangiocytes with Clonochis sinensis excretory-secretory protein and N-nitrosodimethylamine

Background

Clonorchis sinensis is a group I bio-carcinogen responsible for cholangiocarcinoma (CHCA) in humans. However, the mechanism by which C. sinensis promotes carcinogenesis is unclear.

Methodology

Using the human cholangiocyte line H69, we investigated cell proliferation and gap junction protein expression after stimulation with the hepatotoxin N-nitrosodimethylamine (NDMA) and/or excretory-secretory products (ESP) of C. sinensis, which induce inflammation. NDMA and ESP treatment increased proliferation by 146% and the proportion of cells in the G2/M phase by 37%. Moreover, the expression of the cell proliferation-related proteins E2F1, Ki-67, and cancer related protein cytokeratin 19 and Cox-2 increased in response to combined treatment with NDMA and ESP. The gap-junction proteins connexin (Cx) 43 and Cx26 increased. In contrast, Cx32 expression decreased in cells treated with NDMA and ESP. Silencing of Cx43 reduced cell proliferation and significantly suppressed Cx26 and Cox-2 expression.

Conclusions

These results suggest that Cx43 is an important factor in CHCA induced by C. sinensis ESP and NDMA and further investigations targeting this pathway may allow prevention of this deadly disease.

Clonorchis sinensis, a human fluke, resides in the liver of humans and is commonly found in the common bile duct and gall bladder. This parasite is the main cause of cholangiocarcinoma, also called bile duct cancer, in humans. Of note, the excretory-secretory products (ESP) of C. sinensis are known to cause inflammation in the biliary epithelium, which may ultimately result in neoplasms via production of reactive oxygen species and subsequent DNA damage. Together with N-nitrosodimethylamine (NDMA), a potent hepatotoxin that can cause fibrosis and tumors in the liver, ESP led to an increase in the growth and proliferation of cholangiocytes. Our results showed that examination of changes in the expression of gap junction proteins, which are related to tumorigenesis, showed that connexin 43 was upregulated with ESPs from C. sinensis and NDMA. Together, our results suggest that exposure to C. sinensis, in addition to low levels of carcinogen could promote carcinogenesis in the bile duct epithelium via uncontrolled cell-to-cell communication. Moreover, silencing of Cx43 reduced cancer related protein. Therefore, Cx 43 can serve as a potential target for developing a therapeutic strategy for the treatment of cholangiocarcinoma in humans.

Detection of helminths by loop-mediated isothermal amplification assay: a review of updated technology and future outlook

BACKGROUND

Helminths are endemic in more than half of the world's countries, raising serious public health concerns. Accurate diagnosis of helminth infection is crucial to control strategies. Traditional parasitological methods, serological tests and PCR-based assays are the major means of the diagnosis of helminth infection, but they are time-consuming and/or expensive, and sometimes provide inaccurate results. Loop mediated isothermal amplification (LAMP) assay, a sensitive, simple and rapid method was therefore developed for detection of helminths. This study aims to discuss the current status of application of LAMP on helminths detection and to make a comprehensive evaluation about this updated technology and its future outlook by comparing with several other diagnostic methods.

MAIN BODY

This review summarizes LAMP assay applied for helminth detection and helminthiasis surveillance. The basic principle of LAMP is introduced to help better understand its characteristics and each reported assay is assessed mainly based on its detection sensitivity, specificity and limitations, in comparison with other common diagnostic tests. Moreover, we discuss the limitations of the assays so as to clarify some potential ways of improvement.

CONCLUSIONS

Here, we summarize and discuss the advantages, disadvantages and promising future of LAMP in heliminth detection, which is expected to help update current knowledge and future perspectives of LAMP in highly sensitive and specific diagnosis and surveillance of helminthiasis and other parasitic diseases, and can contribute to the elimination of the diseases from endemic areas.

A retrospective administrative database analysis of the association between clonorchiasis or helminthiasis and the development of cholelithiasis

PURPOSE

Parasite infestation (PI) is reportedly related to intrahepatic stones (IHSs) and common bile duct (CBD) stones. This study assessed the association of clonorchiasis and helminthiasis with the sub-types of cholelithiasis.

METHODS

The study cohort consisted of 713 patients who were aged ≥20 years with clonorchiasis or helminthiasis for the first time between 2000 and 2010 from the National Health Insurance Research Database. The controls without clonorchiasis and helminthiasis were randomly selected with a 1:1 propensity score matching. All patients were followed up until the end of 2011 to measure the incidence of cholelithiasis.

RESULTS

The risks of cholelithiasis in the clonorchiasis (adjusted hazard ratio [aHR] = 3.72, 95% confidence interval [CI] = 2.01-6.90) and helminthiasis (aHR = 2.27, 95% CI = 1.25-4.16) were higher than in the non-PI cohort. Patients with clonorchiasis had increased risks of gallstones without bile duct stones (aHR = 3.13, 95% CI = 1.54-6.39) and bile duct stones without gallstones (aHR = 4.75, 95% CI = 1.23-18.4). Patients with helminthiasis had an increased risk of gallstones without bile duct stones (aHR = 2.20, 95% CI = 1.11-4.33), but no higher risk of bile duct stones without gallstones was observed in helminthiasis (aHR = 2.22, 95% CI = 0.54-9.06), despite its high aHR. Neither clonorchiasis nor helminthiasis had an increased risk of concomitant gallstones and bile duct stones.

CONCLUSION

Clonorchiasis is related to the development of not only gallstones, but also bile duct stones, and helminthiasis is only associated with the development of gallstones. However, cases of PI are rare in Taiwan, and this requires more international studies to clarify the association between helminthiasis and bile duct stones.

Clonorchiasis sinensis detected by laparoscopic exploration of biliary tracts in two patients with obstructive jaundice

BACKGROUND

Hepatic clonorchiasis is one of the most prevalent food-borne parasitic diseases worldwide. Clonorchis sinensis, the pathogen, is the major parasitic trigger contributing to cholangitis, cholelithiasis, and even cholangiocarcinoma. Unfortunately, unspecific clinical manifestations of patients with hepatic clonorchiasis tend to mislead clinicians to neglect or misdiagnose them, following ignorance of appropriate therapy. Our case report may shed light on definite diagnosis of clonorchiasis with concomitant cholelithiasis, methodology for surgical drainage of the parasites, and postoperative anthelmintic therapy.

CASE PRESENTATION

Two patients with habit of eating infected raw or undercooked freshwater fish were hospitalized due to right upper quadrant pain and jaundice. Magnetic resonance cholangiopancreatography (MRCP)/computed tomography (CT) detection indicated cholangiolithiasis and cholangiolithiasis with concurrent cholecystolithiasis, respectively. Fecal examinations were both negative for adult worms or eggs of parasites. However, adults of Clonrochis sinensis were detected within hepatobiliary tracts during laparoscopic cholecystectomy. Postoperative drainage and anthelmintic therapy contributed to complete recovery with good prognosis.

CONCLUSIONS

Clonorchiasis provokes cholangiolithiasis and cholecystolithiasis. Standardized treatments for these gallstone patients with concomitant clonorchiasis include surgical removal of the calculus, postoperative T tubule drainage and anthelmintic therapy. Serological test or polymerase chain reaction (PCR)-based approaches might be helpful for diagnosis of clonorchiasis when no eggs are found by stool microscopy. Public health promotion on ceasing to eat raw freshwater fish is essential for prevention and control of clonorchiasis.

Epidemiology of Trematode Infections: An Update

Digenetic trematodes infecting humans are more than 91 species which belong to 46 genera all over the world. According to their habitat in definitive hosts, they are classified as blood flukes (Schistosoma japonicum. S. mekongi, S. mansoni, S. haematobium, and S. intercalatum), liver flukes (Clonorchis sinensis, Opisthorchis viverrini, O. felineus, Metorchis conjunctus, M. bilis, M. orientalis, Fasciola hepatica, F. gigantica, Dicrocoelium dendriticum, and D. hospes), lung flukes (Paragonimus westermani, P. heterotremus, P. skrjabini, P. miyazakii, P. kellicoti, P. mexicanus, P. africanus, and P. uterobilateralis), throat fluke (Clinostomum complanatum), pancreatic fluke (Eurytrema pancreaticum), and intestinal flukes (Metagonimus yokogawai, M. miyatai, M. takahashii, Heterophyes nocens, H. heterophyes, Haplorchis taichui, H. pumilio, H. yokogawai, Centrocestus formosanus, Echinostoma revolutum, E. ilocanum, Isthmiophora hortensis, Echinochasmus japonicus, E. lilliputanus, Artyfechinostomum malayanum, A. sufrartyfex, A. oraoni, Fasciolopsis buski, Gymnophalloides seoi, Neodiplostomum seoulense, Caprimolgorchis molenkampi, Phaneropsolus bonnei, and Plagiorchis muris). The mode of transmission to humans includes contact with cercariae contaminated in water (schistosomes) and ingestion of raw or improperly cooked fish (liver and throat flukes, heterophyids, and echinostomes), snails (echinostomes and gymnophallids), amphibia, reptiles (neodiplostomes), aquatic vegetables (amphistomes), or insect larvae or adults (plagiorchiids, lecithodendriids, and pancreatic fluke). Praziquantel has been proved to be highly effective against most species of trematode infections except fascioliasis. Epidemiological surveys and detection of human infections are required for better understanding of the geographical distribution and endemicity of each trematode species.

Liver Flukes: Clonorchis and Opisthorchis

Clonorchis sinensis, Opisthorchis viverrini, and O. felineus are liver flukes of human and animal pathogens occurring across much of Europe and Asia. Nevertheless, they are often underestimated compared to other, better known neglected diseases in spite of the fact that many millions of people are infected and hundreds of millions are at risk. This is possibly because of the chronic nature of the infection and disease and that it takes several decades prior to a life-threatening pathology to develop. Several studies in the past decade have provided more information on the molecular biology of the liver flukes which clearly lead to better understanding of parasite biology, systematics, and population genetics. Clonorchiasis and opisthorchiasis are characterized by a chronic infection that induces hepatobiliary inflammation, especially periductal fibrosis, which can be detected by ultrasonography. These chronic inflammations eventually lead to cholangiocarcinoma (CCA), a usually fatal bile duct cancer that develops in some infected individuals. In Thailand alone, opisthorchiasis-associated CCA kills up to 20,000 people every year and is therefore of substantial public health importance. Its socioeconomic impacts on impoverished families and communities are considerable. To reduce hepatobiliary morbidity and CCA, the primary intervention measures focus on control and elimination of the liver fluke. Accurate diagnosis of liver fluke infections in both human and other mammalian, snail and fish intermediate hosts, are important for achieving these goals. While the short-term goal of liver fluke control can be achieved by praziquantel chemotherapy, a comprehensive health education package targeting school children is believed to be more beneficial for a long-term goal/solution. It is recommended that a transdisciplinary research or multisectoral control approach including one health and/or eco health intervention strategy should be applied to combat the liver flukes, and hence contribute to reduction of cholangiocarcinoma in endemic areas.