Development and preliminary evaluation of a fluorescence RPA assay for the rapid detection of Necator americanus / 中国热带医学

@#Abstract: Objective To establish a rapid detection assay based on fluorescence recombinase polymerase amplification (RPA) targeting Necator americanus eggs, and to evaluate its efficacy, providing technical support for rapid detection of Necator americanus in fecal samples. Methods The fluorescence RPA primers and probe were designed based on the cox1 gene of Necator americanus and then screened the optimal combination to develop the assay. The genomic DNA of Necator americanus eggs was diluted to 7 concentration gradients including 100 pg/µL, 10 pg/µL, 1 pg/µL, 100 fg/µL, 10 fg/µL, 1 fg/µL, 0.1 fg/µL, to determine the detection limit of the assay. The specificity of the assay was demonstrated by detected genomic DNA from Schistosoma japonicum, Ascaris lumbricoides, Clonorchis sinensis and Fasciola hepatica. A total of 44 fecal samples were collected and DNA extraction was performed, and the modified Kato-Katz method, semi-nest PCR method, and fluorescent RPA method were simultaneously used for detection to evaluate the sensitivity and specificity. Results The established fluorescence RPA assay can specifically amplify a fragment of 194 bp of the Necator americanus cox1 gene within 20 min, with a detection limit of 10 fg/µL. There was no cross-reactivity with Schistosoma japonicum, Ascaris lumbricoides, Clonorchis sinensis, Fasciola hepatica after specificity validation. In 44 fecal samples, 27 positive samples were detected by the fluorescence RPA assay, and 26 positive samples were detected by both the Kato-Katz and the semi-nested PCR. The fluorescence curve of sample number 1 was slightly higher than the negative control in the later stage of the reaction, but did not show a similar trend to the positive control, and was therefore judged to be a suspected negative sample. Compared with the Kato-Katz method and the semi-nest PCR method, The sensitivity of the fluorescent RPA method were 100.00% and the specificity were 94.44%, and the consistency of the detection results was good (Kappa=0.953>0.75). Conclusions The assay based on the fluorescence RPA is an efficient, sensitive and specific technique for detecting Necator americanus and it can be applied for surveillance and early warning of hookworm infection.

Designing of promising Tromethamine-Diflunisal-Pyrrole combinations based on COX binding, drug-properties and safety-Supplementary Data

Gastric issues that accompany the use of NSAIDs (Non-steroid anti-inflammatory drugs) are always a serious global concern. The inhibition of the Cycloxygenase enzyme (COX) limits the prostaglandin synthesis and thereby facilitates the control of pains, inflammation etc. But this creates gastric issues due to the reduction of mucin formation in the stomach. The present work was performed to create a modification in the structure of NSAID drug Diflunisal, to reduce the gastric effect of acidic moiety in the structure and elevate the overall biological properties. The drug Tromethamine, a base used in acidosis treatment was substituted to reduce the acidic issues. The heterocyclic compound pyrrole was substituted to elevate the properties. Neutral, salt, amide and ester combinations of Tromethamine-Diflunisal were designed, optimized and docked to the crystal structures of COX-1 (PDB ID: 6Y3C) and COX-2 (PDB ID: 5IKR) enzymes, using PyRx software. The combinations with lower COX-1 and COX-2 binding energies relative to Diflunisal were noted. It was analysed if the combinations of Diflunisal, Tromethamine and pyrrole lowers drug-properties or induce toxicities. Pyrrole substitution at position R4 was not found favourable for COX binding. Among the favourable combinations, DF19 is the Diflunisal-Pyrrole-Tromethamine combination, equally favourable for binding to COX targets.

Designing of promising Tromethamine-Diflunisal-Pyrrole combinations based on COX binding, drug-properties and safety-Supplementary Data

Gastric issues that accompany the use of NSAIDs (Non-steroid anti-inflammatory drugs) are always a serious global concern. The inhibition of the Cycloxygenase enzyme (COX) limits the prostaglandin synthesis and thereby facilitates the control of pains, inflammation etc. But this creates gastric issues due to the reduction of mucin formation in the stomach. The present work was performed to create a modification in the structure of NSAID drug Diflunisal, to reduce the gastric effect of acidic moiety in the structure and elevate the overall biological properties. The drug Tromethamine, a base used in acidosis treatment was substituted to reduce the acidic issues. The heterocyclic compound pyrrole was substituted to elevate the properties. Neutral, salt, amide and ester combinations of Tromethamine-Diflunisal were designed, optimized and docked to the crystal structures of COX-1 (PDB ID: 6Y3C) and COX-2 (PDB ID: 5IKR) enzymes, using PyRx software. The combinations with lower COX-1 and COX-2 binding energies relative to Diflunisal were noted. It was analysed if the combinations of Diflunisal, Tromethamine and pyrrole lowers drug-properties or induce toxicities. Pyrrole substitution at position R4 was not found favourable for COX binding. Among the favourable combinations, DF19 is the Diflunisal-Pyrrole-Tromethamine combination, equally favourable for binding to COX targets.

Designing of promising Tromethamine-Diflunisal-Pyrrole combinations based on COX binding, drug-properties and safety

Gastric issues that accompany the use of NSAIDs (Non-steroid anti-inflammatory drugs) are always a serious global concern. The inhibition of the Cycloxygenase enzyme (COX) limits the prostaglandin synthesis and thereby facilitates the control of pains, inflammation etc. But this creates gastric issues due to the reduction of mucin formation in the stomach. The present work was performed to create a modification in the structure of NSAID drug Diflunisal, to reduce the gastric effect of acidic moiety in the structure and elevate the overall biological properties. The drug Tromethamine, a base used in acidosis treatment was substituted to reduce the acidic issues. The heterocyclic compound pyrrole was substituted to elevate the properties. Neutral, salt, amide and ester combinations of Tromethamine-Diflunisal were designed, optimized and docked to the crystal structures of COX-1 (PDB ID: 6Y3C) and COX-2 (PDB ID: 5IKR) enzymes, using PyRx software. The combinations with lower COX-1 and COX-2 binding energies relative to Diflunisal were noted. It was analysed if the combinations of Diflunisal, Tromethamine and pyrrole lowers drug-properties or induce toxicities. Pyrrole substitution at position R4 was not found favourable for COX binding. Among the favourable combinations, DF19 is the Diflunisal-Pyrrole-Tromethamine combination, equally favourable for binding to COX targets.

Investigation on population dynamics and Echinococcus infections in small rodents around human settlement in Yushu City, Qinghai Province / 中国血吸虫病防治杂志

Objective To investigate the population dynamics and Echinococcus infections in small rodents around human settlement in Yushu City, Qinghai Province. Methods Rodents were captured using the mouse trap method in pastures from Batang Township and Longbao Township of Yushu City, Qinghai Province on May, August and October, 2018. The body weight and snout-vent length of all captured rodents were measured, and the species was identified according to the rodent morphology. Genomic DNA was extracted from rodent liver specimens and lesion specimens, and the mitochondrial cox1 gene of Echinococcus was amplified using PCR assay for identification of parasite species. In addition, the tissue specimens positive for PCR assay were sampled for pathological examinations. The prevalence of Echinococcus infections was estimated in rodents, and a phylogenetic tree was created based on Echinococcus cox1 gene sequences. Results A total of 285 small rodents were captured, including 143 Ochotona curzoniae (50.2%), 141 Lasiopodomys fuscus (49.5%), and 1 Neodon irene (0.3%), and there was a remarkable variation in habitat selection among these three rodent species. The number of L. fuscus correlated positively with vegetation coverage (r = 0.350, P = 0.264), with the greatest number seen in August, and the number of O. curzoniae negatively with vegetation coverage (r = −0.371, P = 0.235), with the highest number seen in August and the lowest number in May. The female/male ratios of O. curzoniae and voles were 1:0.96 and 0.82:1, respectively. The body weight (r = 0.519, P < 0.01) and snout-vent length (r = 0.578, P < 0.01) of O. curzoniae showed a tendency towards a rise with month, while the body weight (r = −0.401, P < 0.01) and snout-vent length (r = −0.570, P < 0.01) of voles presented a tendency towards a reduction with month. No Echinococcus infection was detected in voles, while 2.1% prevalence of E. shiquicus infection was seen in O. curzoniae. Phylogenetic analysis revealed consistent sequences of cox1 gene from E. shiquicus in Yushu City of Qinghai Province and Shiqu County, Ganzi Tibetan Autonomous Prefecture of Sichuan Province. Conclusions The small rodents around the human settlement in Yushu City of Qinghai Province mainly include O. curzoniae and L. fuscus, with the greatest numbers seen in May and August, respectively. Following the concerted efforts for echinococcosis control, the prevalence of Echinococcus infections is low in small rodents around the human settlement in Yushu City; however, there is still a risk of echinococcosis transmission.

Screening of phytocompounds, molecular docking studies, and in vivo anti-inflammatory activity of heartwood aqueous extract of Pterocarpus santalinus L.f

Objective:To evaluate the anti-inflammatory potential of aqueous extract of Pterocarpus santalinus L.f. heartwood using molecular docking and in vivo experiment. Methods:An aqueous extract of Pterocarpus santalinus heartwood was prepared using a Soxhlet apparatus. Phytocompounds in the extract were tentatively identified using high-resolution mass spectrometry. Molecular docking experiments were carried out to evaluate the binding affinity of selected compounds, phloridzin to cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), prostaglandin E synthase-1 (PGES-1) and 5-lipoxygenase (5-LOX). Anti-inflammatory potential was evaluated by carageenan induced paw edema model in rats. Results:The presence of major component phloridzin along with quercetin, parthenin, ginkgolide B, picrotoxinin, usnic acid, octopine, and epigallocatechin was detected in the extract. Molecular docking study showed that phloridzin inhibited COX-1, COX-2, PGES-1 and 5-LOX with more affinity than ibuprofen and paracetamol. Pterocarpus santalinus heartwood extract at 200 and 400 mg/kg BW showed significant reduction in carageenan-induced hind paw edema in a dose-dependent manner, but the effect was slow when compared with the standard ibuprofen (30 mg/kg p.o.). Conclusions:The study indicated that after clinical trials, the aqueous extract of Pterocarpus santalinus heartwood can be effectively used in phytotherapy to treat inflammation.

Interspecies Phylogenetic Analysis of / 生物医学与环境科学（英文）

Objective@#This study aims to investigate the infection of @*Method@#Infection of the definitive human host and intermediate fish host by @*Results@#In 2016-2020, the average population infection rate of Hunan was 1.38%, while in Tongdao County the rate was up to 26.90%, and the highest fish infection rate was detected in Qiyang County (99.44% in the dorsal fin of @*Conclusion@#The systematically study of

Characterization of Echinostoma miyagawai in domestic ducks in Wuhu City / 中国血吸虫病防治杂志

Objective To investigate the morphological characteristics of Echinostoma miyagawai in domestic ducks in Wuhu area, and to explore the feasibility of the cytochrome oxidase subunit-1 (Cox1) gene as a molecular marker for the identification of E. miyagawai. Methods E. miyagawai was isolated from free-ranged domestic ducks in Wuhu area, and the parasites were stained and identified. In addition, the mitochondrial Cox1 gene of E. miyagawai was amplified using a PCR assay, and the amplification product was sequenced and aligned with the GenBank database to yield the homology for the identification of parasite species in combination with morphological findings. Intra-species comparison was done based on the Cox1 gene sequence. Results The prevalence of E. miyagawai infection was 16.67% in domestic ducks in Wuhu area, and the adult E. miyagawai was 6.6 to 13.2 mm in length. The size of the E. miyagawai Cox1 gene was approximately 660 bp, which had a 99.68% homology to the E. miyagawai accessed in GenBank. The morphological findings were in agreement with molecular identification. Conclusion E. miyagawai infection is common in domestic ducks in Wuhu area, and the mitochondrial Cox1 gene is a feasible marker of intra- and inter-species molecular identification of Echinostoma.

Dirofilaria immitis infestation in imported police (K-9) dogs in Iraq: clinicopathological and molecular investigations study / Infecção por Dirofilaria immitis em cães policiais importados no Iraque: estudo clínico-patológico e de investigações moleculares

Dirofilaria immitis, the cause of heartworm infestation (HWI) or dirofilariasis, affects members of the Canidae and remains a worldwide clinical problem. In Iraq, dirofilariasis was believed absent until 2009, when the Karbala Governorate was reported as an endemic area for canine dirofilariasis. Consequently, this study intended to investigate the occurrence of Dirofilaria immitis in police dogs in one police academy in Iraq and to study the gross and histopathological changes in 5 dead dogs, as well as to identify the species of the causative parasite using PCR technique. Thirty-nine police dogs, aged between 6 months and 12 years were included in this study. For the microfilariae investigation, 5 ml blood samples were collected from all dogs in EDTA tubes and examined by Knott's method. The systemic necropsy performed in five dead dogs showed severe clinical signs of dirofilariasis and tissue specimens were sent for routine histopathological processing. For the molecular analysis, adult worms of the detected Dirofilaria spp. were used for DNA extraction and amplification of the cox1 gene. Fifteen of 39 (38.46%) dogs were diagnosed with moderate to severe microfilariasis. The dead dogs revealed typical severe clinical signs of dirofilariasis. Moreover, typical gross and histopathological changes were also seen, accompanied by generalized thromboembolic lesions, suggesting the occurrence of the caval syndrome. The PCR investigation confirmed that D. immitis was the species present in Iraq. In conclusion, this study establishes that Iraq is a newly reported endemic area for dirofilariasis. Moreover, the infestation occurring in these cases most probably happened inside Iraq. The authors recommend doing further epidemiological studies concerning the occurrence of D. immitis in local dogs as well as in the imported dogs in all Iraqi governorates to better understand the epidemiological map of this disease and to introduce an active treatment and preventive program. Awareness and education regarding this disease should be provided to the veterinarians, dog guiders and people in direct contact with dogs, as this disease is one of the important zoonotic diseases.(AU)

A Dirofilaria immitis, causadora da infestação pelo verme do coração (IVC) ou dirofilariose afeta os membros da família Canidae e ainda é um problema clínico mundial. Até o ano de 2009, acreditava-se que o Iraque fosse livre da dirofilariose, porém nessa ocasião a governadoria de Kerbala foi relatada como uma área endêmica de dirofilariose. Assim, o presente trabalho foi realizado para investigar a ocorrência da Dirofilaria immitis em cães policiais em uma academia de polícia do Iraque, estudar as alterações macroscópicas e histopatológicas em cinco cães mortos, bem como, identificar as espécies do parasita causador com o emprego da técnida de PCR. Trinta e nove cães policiais com 6 meses a 12 anos de idade foram incluídos no estudo. Amostras de sangue de cinco mililitros foram colhidas por animal, em tubos com EDTA e foram examinadas pelo método de Knott. A necropsia sistêmica foi realizada em cinco cães que haviam apresentado sinais clínicos severos de dirofilariose e espécimens dos seus tecidos foram enviados para o processamento histopatológico de rotina. Para a análise molecular dos vermes adultos de Dirofilaria spp, foi empregada a extração do DNA e a amplificação do gene cox1. Quinze de 39(38,46%) cães foram diagnosticados com uma microfilariase variável de moderada para severa. As alterações macroscópicas e histopatológicas foram acompanhadas por lesões generalizadas tromboembólicas sugestivas da ocorrência da síndrome da veia cava. A investigação de PCR confirmou que a D.immitisera a espécie presente no Iraque. A conclusão do estudo estabeleceu que o Iraque deve passar a ser considerado como uma nova área endêmica da dirofilariose. Além da infestação registrada nos casos descritos é provável que ela também esteja presente em outras regiões do Iraque. Os autores recomendam a realização de estudos epidemiológicos para investigar a ocorrência de D.immitis tanto nos cães locais bem como em cães importados em todas as governadorias do Iraque, para ser construído o mapa epidemiológico da distribuição da doença e implantadas as ações de tratamento e de um progrma preventivo. Ações de educação em saúde sobre a doença deverão ser dirigidas para os veterinários, tratadores de cães e para pessoas em geral que tenham contato com os cães, pois esta doença é uma importante zoonose.(AU)

Identity of Spirometra theileri from a Leopard (Panthera pardus) and Spotted Hyena (Crocuta crocuta) in Tanzania

In the present study, a Spirometra species of Tanzania origin obtained from an African leopard (Panthera pardus) and spotted hyena (Crocuta crocuta) was identified based on molecular analysis of cytochrome c oxidase I (cox1) and NADH dehydrogenase subunit I (nad1) as well as by morphological observations of an adult tapeworm. One strobila and several segments of a Spirometra species were obtained from the intestine of an African male leopard (Panthera pardus) and spotted hyena (Crocuta crocuta) in the Maswa Game Reserve of Tanzania. The morphological characteristics of S. theileri observed comprised 3 uterine loops on one side and 4 on the other side of the mid-line, a uterine pore situated posterior to the vagina and alternating irregularly either to the right or left of the latter, and vesicular seminis that were much smaller than other Spirometra species. Sequence differences in the cox1 and nad1 genes between S. theileri (Tanzania origin) and S. erinaceieuropaei were 10.1% (cox1) and 12.0% (nad1), while those of S. decipiens and S. ranarum were 9.6%, 9.8% (cox1) and 13.0%, 12.6% (nad1), respectively. The morphological features of the Tanzania-origin Spirometra specimens coincided with those of S. theileri, and the molecular data was also consistent with that of S. theileri, thereby demonstrating the distribution of S. theileri in Tanzania. This places the leopard (Panthera pardus) and spotted hyena (Crocuta crocuta) as new definitive hosts of this spirometrid tapeworm.

Genetic Identification of Spirometra erinaceieuropaei Spargana in Liaoning and Hubei Provinces, PR China

Spargana were collected from human and frogs in Liaoning and Hubei Provinces, China. PCR amplification and direct sequencing of A cox1 fragment was PCR-amplified from genomic DNA extracted from 7 specimens (5 from humans and 2 from frogs). The cox1 fragment (390 bp) showed 97–100% similarity to the reference sequence of S. erinaceieuropaei and 88–89% to the reference sequence of S. decipiens. There were 1–12 bases different between these worms, but no obvious genetic variation (0–3.3%) to the references. There was little difference of cox1 gene between sparganum samples of humans and frogs (1–3%). This study is the first report on S. erinaceieuropaei spargana from humans in Liaoning and Hubei Provinces.

Prevalence and Molecular Characterization of Echinococcus granulosus Sensu Stricto in Northern Xinjiang, China

Echinococcus granulosus is an important zoonotic parasite globally causing cystic echinococcosis (CE) in humans and animals. In this study, prevalence of CE and variation of cox1 gene sequence were analyzed with isolates E. granulosus collected from different areas in northern Xinjiang, China. The survey showed that 3.5% of sheep and 4.1% of cattle were infected with CE. Fragment of cox1 was amplified from all the positive sheep and cattle samples by PCR. In addition, 26 positive samples across the 4 areas were included. The isolates were all E. granulosus sensu stricto (s.s.) containing 15 haplotypes (Hap1-15), and clustered into 2 genotypes, G1 (90.1%, 91/101) and G3 (9.9%, 10/101). Hap1 was the most common haplotype (48.5%, 49/101). Hap9 were found in humans samples, indicating that sheep and cattle reservoir human CE. It is indicate that E. granulosus may impact on control of CE in livestock and humans in the region.

Hymenolepis microstoma (Cestoda: Hymenolepididae) en ratones caseros ( Mus musculus ) de Lima, Perú / Hymenolepis microstoma (Cestoda: Hymenolepididae) in house mice (Mus musculus) from Lima, Peru

Un total de 12 cestodos adultos se colectaron de los conductos biliares de ratones domésticos (Mus musculus) provenientes de Lima, Perú. Diversas características del escólex y proglotis maduros del cestodo fueron observadas para la identificación morfológica. Así mismo, se realizó un diagnóstico molecular mediante un PCR y secuenciación parcial del gen mitocondrial citocromo c oxidasa subunidad 1 (cox1). Todos los cestodos fueron identificados como Hymenolepis microstoma por morfología y métodos moleculares. El aislado de H. microstoma de Perú mostró una similitud de secuencia significativa (> 99%) con los aislados de H. microstoma previamente reportados. Nuestro informe confirma la presencia del parásito en ratones de Lima.

A total of 12 adult cestodes were collected from the bile ducts of domestic mice (Mus musculus) from Lima, Peru. Various features of the scolex and mature proglottids of the tapeworms were observed for morphological identification. A molecular diagnosis was performed by PCR-based partial sequencing of mitochondrial gene of cytochrome c oxidase subunit 1 (cox1). All cestodes were identified as Hymenolepis microstoma by morphology and molecular methods. The H. microstoma isolate from Peru showed significant sequence similarity with previously reported isolates of H. microstoma (>99%). Our report confirms the presence of the parasite in mice from Lima.

Molecular and Morphologic Identification of Spirometra ranarum Found in the Stool of African Lion, Panthera leo in the Serengeti Plain of Tanzania

The present study was performed with morphological and molecular analysis (cox1 and nad1 mitochondrial genes) to identify the proglottids of spirometrid tapeworm found in the stool of an African lion, Panthera leo, in the Serengeti plain of Tanzania. A strand of tapeworm strobila, about 75 cm in length, was obtained in the stool of a male African lion in the Serengeti National Park (34° 50′ E, 02° 30′ S), Tanzania, in February 2012. The morphological features of the adult worm examined exhibited 3 uterine coils with a bow tie appearance and adopted a diagonal direction in the second turn. The posterior uterine coils are larger than terminal uterine ball and the feature of uteri are swirling rather than spirally coiling. The sequence difference between the Spirometra species (Tanzania origin) and S. erinaceieuropaei (GenBank no. KJ599680) was 9.4% while those of S. decipiens (GenBank no. KJ599679) differed by 2.1% in the cox1 and nad1 genes. Phylogenetic tree topologies generated using the 2 analytic methods were identical and presented high level of confidence values for the 3 major branches of the 3 Spirometra species in the cox1 gene. The morphological and molecular findings obtained in this study were nearly coincided with those of S. ranarum. Therefore, we can know for the first time that the African lion, Panthera leo, is to the definitive host of this tapeworm.

Genetic and Morphologic Identification of Spirometra ranarum in Myanmar

In the present study, we identified a Spirometra species of Myanmar origin (plerocercoid) by molecular analysis using mitochondrial cox1 and nad1 genes, as well as by morphological observations of an adult tapeworm. Spargana specimens were collected from a paddy-field in Taik Kyi Township Tarkwa Village, Yangon, Myanmar in December 2017. A total of 5 spargana were obtained from 20 frogs Hoplobatrachus rugulosus; syn: Rana rugulosa (Wiegmann, 1834) or R. tigrina (Steindachner, 1867). The plerocercoids were used for experimental infection of a dog. After 4 weeks of infection, an adult tapeworm was recovered from the intestine of the dog. Morphologically, the distinct features of Spirometra sp. (Myanmar origin) relative to S. erinaceieuropaei and S. decipiens include a uterine morphology comprising posterior uterine coils that larger than the terminal uterine ball and coiling of the uteri diagonally (swirling) rather than spirally. The cox1 sequences (1,566 bp) of the Myanmar-origin Spirometra species showed 97.9% similarity to a reference sequence of S. decipiens (GenBank no. KJ599679) and 90.5% similarity to a reference sequence of S. erinaceieuropaei (GenBank no. KJ599680). Phylogenetic tree topologies were identical and presented high confidence level of values for the 3 major branches of the 3 Spirometra species in cox1 and nad1 genes. These results indicated that Myanmar-origin Spirometra species coincided with those of S. ranarum and may be considered as a valid species.

A Case of Coenurosis in a Wild Rabbit (Lepus sinensis) Caused by Taenia serialis Metacestode in Qinghai Tibetan Plateau Area, China

Six cystic metacestodes were found in the abdominal muscles of a wild rabbit, Lepus sinensis, in China. The coenurus contained one or more scolices armed with hooklets. Mitochondrial cox1 (1,623 bp) confirmed 98% homology with cox1 of Taenia serialis. This is the first report of T. serialis infection in an intermediate host in the Qinghai Tibetan Plateau Area, China.

Spirometra decipiens (Cestoda: Diphyllobothriidae) Collected in A Heavily Infected Stray Cat from the Republic of Korea

Morphological and molecular characteristics of spirometrid tapeworms, Spirometra decipiens, were studied, which were recovered from a heavily infected stray cat road-killed in Eumseong-gun, Chungcheongbuk-do (Province), the Republic of Korea (=Korea). A total of 134 scolices and many broken immature and mature proglottids of Spirometra tapeworms were collected from the small intestine of the cat. Morphological observations were based on 116 specimens. The scolex was 22.8–32.6 mm (27.4 mm in average) in length and small spoon-shape with 2 distinct bothria. The uterus was coiled 3–4 times, the end of the uterus was ball-shaped, and the vaginal aperture shaped as a crescent moon was closer to the cirrus aperture than to the uterine aperture. PCR amplification and direct sequencing of the cox1 target fragment (377 bp in length and corresponding to positions 769–1,146 bp of the cox1 gene) were performed using total genomic DNA extracted from 134 specimens. The cox1 sequences (377 bp) of the specimens showed 99.0% similarity to the reference sequence of S. decipiens and 89.3% similarity to the reference sequence of S. erinaceieuropaei. In the present study, we report a stray cat heavily infected with S. decipiens identified by mitochondrial cox1 sequence analysis and morphological examinations of the adult worms.

Genotyping and gene nucleotide polymorphism of epidemic strain of Echino-coccus granulosus metacestode from humans and sheep in Tianjun region, Qinghai Province / 中国血吸虫病防治杂志

Objective To understand the genotypes and nucleotide polymorphisms of Echinococcus granulosus metacestode from humans and sheep in Tianjun region,Qinghai Province. Methods The specific primers were designed according to the cox1 and nad1 genes of E.granulosus mitochondrial genome sequences accessed by GenBank.The primers were used to detect the cyst samples from 16 sheep and 2 humans infected with E.granulosus in Tianjun region of Qinghai Province by PCR,then the PCR amplification products were sequenced,the genotypes and nucleotide polymorphisms of the cox1 and nad1 genes were analyzed.Results The 18 isolated samples all belonged to E.granulosus G1 genotype.Among all the isolates,9 haplotypes ex-isted in the cox1 gene with 16 nucleotide mutation sites,and there were 0 to 5 nucleotide differences with the highest variation rate of 0.31%,whereas 7 haplotypes occurred with 15 nucleotide mutation sites,and there were 1 to 8 nucleotide differences with the highest variation rate of 0.89% for the nad1 gene.Conclusions The epidemic genotype of E.granulosus is G1 in hu-mans and sheep in Tianjun region of Qinghai Province,and the nucleotide polymorphisms of the cox1 gene were more abundant than those of the nad1 gene,and the resolution of the nucleotide polymorphisms of cox1 gene is higher than that of the nad1 gene used in E.granulosus isolates.

Molecular Identification of Diphyllobothrium latum from a Pediatric Case in Taiwan

Human diphyllobothriasis is a parasitic disease caused by ingestion of larvae (plerocercoids) in raw or undercooked fish and commonly found in temperate areas. Rare cases were reported in tropical or subtropical areas especially in children. The first documented case of pediatric diphyllobothriasis in Taiwan had been reported 11 years ago. Here, we report another 8-year-old girl case who presented with a live noodle-like worm hanging down from her anus, with no other detectable symptoms. We pulled the worm out and found the strobila being 260 cm in length. Examination of gravid proglottids showed that they were wider than their lengths, containing an ovoid cirrus sac in the anterior side and the rosette-shaped uterus. Eggs extracted from the uterus were ovoid and operculated. Diphyllobothrium latum was confirmed by molecular analysis of the mitochondrial DNA cytochrome c oxidase subunit 1 (cox1) gene. The girl was treated with a single oral dose of praziquantel, and no eggs or proglottids were observed from her stool in the subsequent 3 months. The reemergence of human diphyllobothriasis in non-endemic countries is probably due to prevalent habit of eating imported raw fish from endemic areas. This pediatric case raised our concern that human diphyllobothriasis is likely underestimated because of unremarkable symptoms.

Practical Algorisms for PCR-RFLP-Based Genotyping of Echinococcus granulosus Sensu Lato

Echinococcus granulosus sensu lato (s.l.) is a causative agent of cystic echinococcosis or cystic hydatid disease in humans and domestic and wild animals. The disease is a serious health problem in countries associated with poverty and poor hygiene practices, particularly in livestock raising. We introduced a practical algorism for genotyping the parasite, which may be useful to many developing countries. To evaluate the efficiency of the algorism, we genotyped 3 unknown strains isolated from human patients. We found that unknowns 1 and 3 were included in G1, G2, and G3 genotypes group and unknown 2 was included in G4 genotype (Echinococcus equinus) according to the algorisms. We confirmed these results by sequencing the 3 unknown isolates cox1 and nad1 PCR products. In conclusion, these new algorisms are very fast genotype identification tools that are suitable for evaluating E. granulosus s.l. isolated from livestock or livestock holders, particularly in developing countries.