Papers by Hirokazu Kouguchi
Russian journal of theriology, Nov 16, 2021
Echinococcosis is a zoonosis caused by the tapeworm Echinococcus multilocularis, which uses red f... more Echinococcosis is a zoonosis caused by the tapeworm Echinococcus multilocularis, which uses red fox (Vulpes vulpes) as a principle definitive host. To decrease E. multilocularis prevalence in red foxes, feeding the "fox bait" containing anthelmintic praziquantel to red foxes is effective. However, a previous investigation conducted in Hokkaido, Japan showed that raccoon dogs (Nyctereutes viverrinus albus), raccoons (Procyon lotor), domestic cats (Felis catus), and murids frequently consumed fox baits without the anthelmintic praziquantel, suggesting they compete with red foxes for the bait. On the other hand, anthelmintic praziquantel has a bitter taste and unpleasant odor to dogs (Canis lupus familiaris) and cats. The inclusion of anthelmintic praziquantel in the bait may deter the consumption of fox baits by nontarget mammals. Therefore, by using camera traps, we examined the seasonal consumption of fox baits with the anthelmintic praziquantel by mammals in Memuro, Tokachi District, Hokkaido, Japan, from May to October, 2019. We found that red foxes, raccoons, raccoon dogs, murids, and Eurasian red squirrels (Sciurus vulgaris) frequently consumed fox baits. Therefore, the bitterness and smell of the bait do not efficiently work to prevent consumption by non-target mammals. Of those, raccoon dogs were most frequent consumers of the fox bait. Raccoons and Eurasian red squirrels also frequently consumed the fox bait, especially in spring and in autumn, respectively. These results show competition for fox baits by non-target mammals. This should be considered for planning of the baiting campaign.
International Journal for Parasitology, Oct 1, 2021
The early-phase migration dynamics of Echinococcus multilocularis in the intermediate hosts remai... more The early-phase migration dynamics of Echinococcus multilocularis in the intermediate hosts remain largely unknown. We compared the parasite burden in the intestine, liver and faeces of DBA/2 and C57BL/6 mouse strains using parasite-specific quantitative PCR. Our results indicated that the parasites invaded mainly from the middle segments of the small intestine and completed migration to the liver within 24 h p.i. C57BL/6 mice had lower parasite DNA burdens in the intestine and liver but higher in the faeces than DBA/2 mice, suggesting that parasite invasion of the intestine may be a critical stage regulating E. multilocularis infection in mice.
Parasitology International
Alveolar echinococcosis (AE) is a zoonosis caused by the metacestode of Echinococcus multilocular... more Alveolar echinococcosis (AE) is a zoonosis caused by the metacestode of Echinococcus multilocularis. The published genome of E. multilocularis showed that approximately 86% of its genome is non-coding. Micro RNAs (miRNAs) are small noncoding regulatory RNAs, and recent studies on parasitic helminths expect miRNAs as a promising target for drug development and diagnostic markers. Prior to this study, only a few studies reported the E. multilocularis miRNA profiles in the intermediate host. The primary objective of this study was to characterize miRNA profiles via small RNA-seq in E. multilocularis Nemuro strain, a laboratory strain of Asian genotype, using mice perorally infected with the parasite eggs. The data were then compared with two 3 previously published small RNA-seq data. We identified 44 mature miRNAs as E. multilocularis origin out of the 68 mature miRNA sequences registered in the miRNA database miRbase. The highest quantities of miRNAs detected were miR-10-5p, followed by bantam-3p, let-7-5p, miR-61-3p, and miR-71-5p. The top two most abundant miRNAs (miR-10-5p and bantam-3p) accounted for approximately 80.9% of the total parasite miRNAs. The highly expressed miRNA repertoire is mostly comparable to that obtained from the previous experiment using secondary echinococcosis created by an intraperitoneal administration of metacestodes. A detailed characterization and functional annotations of these shared miRNAs will lead to a better understanding of parasitic dynamics, which could provide a basis for the development of novel diagnostic and treatment methods for AE.
Food Chemistry: Molecular Sciences
Omphalotus japonicus is a major toxic mushroom in Japan. When food poisoning caused by O. japonic... more Omphalotus japonicus is a major toxic mushroom in Japan. When food poisoning caused by O. japonicus occurs, quick and accurate identification using a method that does not rely on morphological discrimination is required. Because the loop-mediated isothermal amplification (LAMP) method meets these requirements, we developed a LAMP method for detecting O. japonicus. Amplification occurred within 60 min, and the presence or absence of O. japonicus was confirmed within 2 h, including the DNA extraction protocol. The LAMP method did not show cross-reactivity with 13 species of edible mushrooms, had high specificity toward O. japonicus, and had sufficient detection sensitivity even in a mixed mushroom sample containing 1% O. japonicus. Additionally, O. japonicus could be detected in simulated food poisoning samples of heated and digested mushrooms, and in actual food poisoning residual samples.
The cotton rat (Sigmodon hispidus) is a laboratory rodent used for studying human infectious dise... more The cotton rat (Sigmodon hispidus) is a laboratory rodent used for studying human infectious diseases. However, a lack of suitable anesthetic agents inconveniences the use of cotton rats in surgical manipulation. This study demonstrated that subcutaneous injection of the mixture of medetomidine, midazolam, and butorphanol (0.15, 2.0, and 2.5 mg/kg, respectively), which is a suitable anesthetic agents for mice and rats, produced an anesthetic duration of more than 50 min in cotton rats. We also demonstrated that 0.15 mg/kg of atipamezole, an antagonist of medetomidine, produced a quick recovery from anesthesia in cotton rats. This indicated that the anesthetic mixture of medetomidine, midazolam, and butorphanol, functioned as a useful and effective anesthetic for short-term surgery in cotton rats.
Molecular and biochemical parasitology, 2018
Alveolar echinococcosis (AE) is a zoonotic parasitosis caused by larvae of the fox tapeworm, Echi... more Alveolar echinococcosis (AE) is a zoonotic parasitosis caused by larvae of the fox tapeworm, Echinococcus multilocularis. E. multilocularis is distributed widely in the Northern hemisphere, causing serious health problems in various animals and humans. E. multilocularis, like other cestodes, lacks a digestive tract and absorbs essential nutrients, including glucose, across the syncytial tegument on its external surface. Therefore, it is hypothesized that E. multilocularis uses glucose transporters on its surface similar to a closely-related species, Taenia solium. Based on this hypothesis, we cloned and characterized glucose transporter homologues from E. multilocularis. As a result, we obtained full-length sequences of 2 putative glucose transporter genes (EmGLUT1 and EmGLUT2) from E. multilocularis. In silico analysis predicted that these were classified in the solute carrier family 2 group. Functional expression analysis using Xenopus oocytes demonstrated clear uptake of 2-deoxy-...
Parasitology International, 2021
Canines serve as the definitive host of Echinococcus multilocularis. This study evaluated the sen... more Canines serve as the definitive host of Echinococcus multilocularis. This study evaluated the sensitivity of the Mini-FLOTAC technique (MF) for the detection of E. multilocularis eggs in definitive hosts. First, we investigated the effects of heat inactivation and preservative conditions on the detection rate of eggs obtained from experimentally infected dogs. The sensitivity of MF was compared with that of eight other techniques: the centrifugal flotation with sucrose or zinc sulfate, MGL, AMS III, and a combination of MF and flotation/sedimentation techniques. Finally, we compared the sensitivity of MF and the centrifugal flotation with sucrose for the feces of E. multilocularis-infected foxes. The detection rate reached a plateau level with a specific gravity (s.g.) 1.22 for fresh eggs, but the highest rates were obtained with s.g. greater than 1.32 for heat-inactivated eggs. There was no significant difference in the detection rate among the preservative conditions. MF showed significantly higher EPG than the other techniques. Moreover, it showed higher diagnostic sensitivity for the fox feces than the centrifugal flotation technique. These results suggest that heat inactivation may alter s.g of E. multilocularis eggs and that MF with zinc sulfate (s.g. = 1.32) would be effective for detecting heat-inactivated E. multilocularis eggs.
Russian Journal of Theriology, 2021
Echinococcosis is a zoonosis caused by the tapeworm Echinococcus multilocularis, which uses red f... more Echinococcosis is a zoonosis caused by the tapeworm Echinococcus multilocularis, which uses red fox (Vulpes vulpes) as a principle definitive host. To decrease E. multilocularis prevalence in red foxes, feeding the "fox bait" containing anthelmintic praziquantel to red foxes is effective. However, a previous investigation conducted in Hokkaido, Japan showed that raccoon dogs (Nyctereutes viverrinus albus), raccoons (Procyon lotor), domestic cats (Felis catus), and murids frequently consumed fox baits without the anthelmintic praziquantel, suggesting they compete with red foxes for the bait. On the other hand, anthelmintic praziquantel has a bitter taste and unpleasant odor to dogs (Canis lupus familiaris) and cats. The inclusion of anthelmintic praziquantel in the bait may deter the consumption of fox baits by nontarget mammals. Therefore, by using camera traps, we examined the seasonal consumption of fox baits with the anthelmintic praziquantel by mammals in Memuro, Tokachi District, Hokkaido, Japan, from May to October, 2019. We found that red foxes, raccoons, raccoon dogs, murids, and Eurasian red squirrels (Sciurus vulgaris) frequently consumed fox baits. Therefore, the bitterness and smell of the bait do not efficiently work to prevent consumption by non-target mammals. Of those, raccoon dogs were most frequent consumers of the fox bait. Raccoons and Eurasian red squirrels also frequently consumed the fox bait, especially in spring and in autumn, respectively. These results show competition for fox baits by non-target mammals. This should be considered for planning of the baiting campaign.
Data in Brief, 2020
Please cite this article as: H. Kouguchi et al., Adult worm exclusion and histological data of do... more Please cite this article as: H. Kouguchi et al., Adult worm exclusion and histological data of dogs repeatedly infected with the cestode Echinococcus multilocularis, Data in brief,
Echinococcosis, 2017
As an efficient drug for alveolar echinococcosis (AE) is still not available, new chemotherapy ta... more As an efficient drug for alveolar echinococcosis (AE) is still not available, new chemotherapy targets are necessary. The mitochondrial respiratory chain may be a good drug candidate because parasite respiratory chains are quite different from those of mammalian hosts. For example, Ascaris suum possesses an NADH-fumarate reductase system (fumarate respiration) that is highly adapted to anaerobic environments such as the small intestine. It is composed of mitochondrial complex I (NADH-ubiquinone reductase), complex II (succinate-ubiquinone reductase), and rhodoquinone. We previously demonstrated that fumarate respiration is also essential in E. multilocularis. Quinazoline, a complex I inhibitor, inhibited growth of E. multilocularis larvae in vitro. These results indicate that fumarate respiration could be a target for E. multilocularis therapy. In the current chapter, we focused on complex II, which is another component of this system, because quinazoline exhibited strong toxicity to mammalian mitochondria. We evaluated the molecular and biochemical characterization of E. multilocularis complex II as a potential drug target. In addition, we found that ascofuranone, a trypanosome cyanide-insensitive alternative oxidase inhibitor, inhibited E. multilocularis complex II at the nanomolar order. Our findings demonstrate the potential development of targeted therapy against Echinococcus complex II.
Molecular and Biochemical Parasitology, 2018
Alveolar echinococcosis (AE) is a zoonotic parasitosis caused by larvae of the fox tapeworm, Echi... more Alveolar echinococcosis (AE) is a zoonotic parasitosis caused by larvae of the fox tapeworm, Echinococcus multilocularis. E. multilocularis is distributed widely in the Northern hemisphere, causing serious health problems in various animals and humans. E. multilocularis, like other cestodes, lacks a digestive tract and absorbs essential nutrients, including glucose, across the syncytial tegument on its external surface. Therefore, it is hypothesized that E. multilocularis uses glucose transporters on its surface similar to a closely-related species, Taenia solium. Based on this hypothesis, we cloned and characterized glucose transporter homologues from E. multilocularis. As a result, we obtained full-length sequences of 2 putative glucose transporter genes (EmGLUT1 and EmGLUT2) from E. multilocularis. In silico analysis predicted that these were classified in the solute carrier family 2 group. Functional expression analysis using Xenopus oocytes demonstrated clear uptake of 2-deoxy-D-glucose (2-DG) by EmGLUT1, but not by EmGLUT2 in this experimental system. EmGLUT1 was shown to have relatively high glucose transport activity. Further analyses using the Xenopus oocyte system revealed that 2-DG uptake of EmGLUT1 did not depend on the presence or concentration of Na+ nor H+, respectively. Immunoblot analyses using cultured metacestode, ex vivo protoscolex, and adult worm samples demonstrated that both EmGLUTs were stably expressed during each developmental stage of the parasite. Based on the above-mentioned findings, we conclude that EmGLUT1 is a simple facilitated glucose transporter and possibly plays an important role in glucose uptake by E. multilocularis throughout its life cycle.
Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases, Jan 17, 2018
The resistance/susceptibility to Echinococcus multilocularis infection in mice is genetically con... more The resistance/susceptibility to Echinococcus multilocularis infection in mice is genetically controlled. However, genetic factors responsible for these differences remain unknown. Our previous study in genetic linkage analysis has revealed that there is a significant quantitative trait locus (QTL) for the establishment of cyst (Emcys1), and a highly significant QTL for the development of protoscolex of E. multilocularis larvae (Empsc1), on mouse chromosomes 6 and 1, respectively. The current study aimed to confirm these QTLs and narrow down the critical genetic region that controls resistance/susceptibility to E. multilocularis infection by establishing congenic and subcongenic lines from C57BL/6 (B6) and DBA/2 (D2) mice. For protoscolex development phenotype, two congenic lines, B6.D2-Empsc1 and D2.B6-Empsc1 were developed, where responsible QTL, Empsc1 was introgressed from D2 into B6 background and vice versa. For cyst establishment phenotype, two congenic lines, B6.D2-Emcys1 an...
Histology and histopathology, 2018
Pharyngeal pouches in mammals develop into specific derivatives. If the differentiation of the ph... more Pharyngeal pouches in mammals develop into specific derivatives. If the differentiation of the pharyngeal pouches is anomalous, their remnants can result in cysts, sinuses, and fistulae in the differentiated organs or around the neck. In the present study, we found several pharyngeal pouch remnants, such as cystic structures in thymus and parathyroid gland and fossulae extended from the piriform fossa, in the inbred cotton rats maintained at Hokkaido Institute of Public Health (HIS/Hiph) and University of Miyazaki (HIS/Mz). In HIS/Hiph, the fossulae extended from the apex of the piriform fossa into the thyroid glands and were lined with stratified squamous and cuboidal epithelium. Calcitonin-positive C-cells were present within their epithelium in HIS/Hiph. In contrast, the fossulae of HIS/Mz ran outside the thyroid glands toward the parathyroid glands; they were lined with columnar ciliated epithelium and a few goblet cells, but had no C-cells, which was consistent with the cystic ...
Experimental biology and medicine (Maywood, N.J.), 2018
Cotton rat ( Sigmodon hispidus) is a useful experimental rodent for the study of human infectious... more Cotton rat ( Sigmodon hispidus) is a useful experimental rodent for the study of human infectious diseases. We previously clarified that cotton rats, particularly females, developed chronic kidney disease characterized by cystic lesions, inflammation, and fibrosis. The present study investigated female-associated factors for chronic kidney disease development in cotton rats. Notably, female cotton rats developed separation of the pelvic symphysis and hypertrophy in the vaginal parts of the cervix with age, which strongly associated with pyometra. The development of pyometra closely associated with the deterioration of renal dysfunction or immunological abnormalities was indicated by blood urea nitrogen and serum creatinine or spleen weight and serum albumin/globulin ratio, respectively. These parameters for renal dysfunction and immunological abnormalities were statistically correlated. These phenotypes found in the female reproductive organs were completely inhibited by ovariectomy...
Data in brief, 2018
he data set presented in this article is related to a previous research article entitled " T... more he data set presented in this article is related to a previous research article entitled " The timing of worm exclusion in dogs repeatedly infected with the cestode " (Kouguchi et al., 2016) [1]. This article describes the genes >2-fold up- or down-regulated in the first- and repeated-infection groups compared to the healthy controls group. The gene expression profiles were generated using the Agilent-021193 Canine (V2) Gene Expression Microarray (GPL15379). The raw and normalized microarray data have been deposited with the Gene Expression Omnibus (GEO) database under accession number GSE105098.
Parasitology Research, 2017
The use of copro-DNA detection methods for the diagnosis of canine Echinococcus multilocularis in... more The use of copro-DNA detection methods for the diagnosis of canine Echinococcus multilocularis infection was evaluated with a focus on DNA extraction techniques: two commercial kits and a modified alkaline-sodium dodecyl sulfate (SDS) technique. Dog feces (0.2 g) mixed with a protoscolex or with 1 or 10 eggs of E. multilocularis were subjected to DNA detection following extraction by these methods. DNA was extracted from all protoscolex samples by all methods, but success for samples with eggs depended on extraction technique with the modified technique showing success on all samples. Following experimental infection of dogs, copro-DNA was successfully extracted from fecal samples (0.2 g) of dogs in the patent period by all methods. In the prepatent period, PCR testing of feces subsamples (0.2 g) extracted by each technique was positive at a rate of 79.6-94.4%. Extraction by the modified technique with fecal samples of over 1 g showed detection of copro-DNA in all samples in both the patent and prepatent periods, and it produced reproducible detection in the addition recovery test using feces from 72 different domestic dogs. As copro-DNA was detected for at least 1 day following deworming with administration of anthelmintic drugs in experimentally infected dogs, diagnostic deworming might be useful for clinical examination. Using the present detection method can provide quick and accurate diagnosis of canine E. multilocularis infection, which with prompt management and treatment of infected dogs can prevent pet owners from becoming infected and prevent echinococcosis from spreading into non-endemic areas.
Histochemistry and Cell Biology, 2016
The cotton rat (Sigmodon hispidus) is a laboratory rodent that has been used for studies on human... more The cotton rat (Sigmodon hispidus) is a laboratory rodent that has been used for studies on human infectious diseases. In the present study, we observed that female cotton rats, not the male cotton rats, developed chronic anemia characterized by reduced red blood cell, hemoglobin, and hematocrit levels from 5 to 9 months of age without any changes in the mean corpuscular hemoglobin and volume levels. In peripheral blood, the reticulocyte count did not increase in response to anemia in female cotton rats, and no extramedullary hematopoiesis was observed in the liver or spleen. Further, the serum levels of urea nitrogen and creatinine increased from 5 to 9 months of age in female cotton rats compared to male cotton rats, and these increases became more prominent from 10 months of age onward, indicating chronic kidney disease. Histopathologically, female cotton rats manifested tubulointerstitial lesions characterized by the infiltration of mononuclear cells, including plasma cells and CD3(+) T-cells, as well as the dilation of calbindin-D28k(+) distal tubules from 5 to 9 months of age. The severity of these lesions progressed from 10 months of age onward, and renal fibrotic features and numerous tubular cysts appeared without any obvious glomerular lesions. A significant decrease in the erythropoietin protein levels was observed in the kidney of aged female cotton rats, and significant correlations were detected between anemia and tubulointerstitial damage. These results suggest that aged female cotton rats chronically develop renal anemia, and this rodent may serve as a novel model to elucidate its pathogenesis.
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Papers by Hirokazu Kouguchi