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Bernardová N, Novák J, Fan CK, Kolářová L, Chanová M. Toxocara canis infections in mice: from subtle to severe consequences in 100 weeks. J Helminthol 2025; 99:e14. [PMID: 39916564 DOI: 10.1017/s0022149x24000786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2025]
Abstract
Toxocara canis is a widespread parasite of canids with a wide range of paratenic hosts, but also one of the overlooked agents causing nervous system infections of humans. Previous experimental infections of mice demonstrated the impact of high infection doses of larvae on neurobehavioral disorders and pathological changes. In contrast to previous studies, we aimed to investigate the long-term (up to 100 weeks) impact of low- to high-dose infection in mice. We focused on their physical condition, motor skills, and the accompanying pathologies in the brain. Three groups of BALB/c mice were infected with 10, 100, and 1000 T. canis larvae/mouse and specific anti-T. canis excretory-secretory antigens immunoglobulin G antibody response, general condition, and motor skills were tested in defined intervals within 100 weeks after infection. The number of larvae in selected organs was assessed and the pathological changes in the brain were studied histologically. As a result, subtle to severe impairments in general condition and motor skills were detected, with generally earlier onsets occurring the higher the infection dose was. The specific immunoglobulin G antibody levels corresponding to the infection dose were detected in all infected groups. Necrosis, cellular infiltrations, and foamy cells developed in moderate- and high-infection dose mice, in contrast with hemorrhages detected in all groups. This study demonstrated the long-term negative impact of T. canis infection on the paratenic host, particularly at moderate and high infectious doses. Although pathological changes in the brain were observed even in low-infection dose mice, their physical and motor condition was comparable to the control group.
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Affiliation(s)
- Nicol Bernardová
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Jan Novák
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Chia-Kwung Fan
- Department of Molecular Parasitology and Tropical Diseases, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Libuše Kolářová
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
- National Reference Laboratory for Tissue Helminthoses, General University Hospital in Prague, Prague, Czechia
| | - Marta Chanová
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
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Liravizadeh S, Abdolahi Khabisi S, Salimi Khorashad A, Mirahmadi H. Molecular Determination of Toxocara spp. Eggs Isolated from Public Parks and Playgrounds in Zahedan, Southeast Iran. J Parasitol Res 2024; 2024:2132696. [PMID: 38939904 PMCID: PMC11208816 DOI: 10.1155/2024/2132696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 04/15/2024] [Accepted: 05/06/2024] [Indexed: 06/29/2024] Open
Abstract
Background Human toxocariasis (HT) is a zoonotic disease with a global expansion. Contaminated soil with Toxocara spp. eggs is the main source of human infection, which may lead to severe complications depending on the organs invaded by migrating larvae. Aim This study is aimed at eliciting the prevalence of Toxocara spp. eggs in public parks in Zahedan, southeast Iran, and providing new insight into the soil contamination rate in this area using microscopic and molecular methods. Methods Based on five municipal districts, 240 soil samples were collected from public parks and playgrounds in Zahedan. The modified Sheather's flotation technique was employed to isolate Toxocara spp. eggs from the soil, followed by microscopic assessment and molecular evaluation of internal transcribed spacer 1 and 2 ribosomal deoxyribonucleic acid (ITS1 and 2 rDNA) using nested polymerase chain reaction (nested PCR) to identify the presence of Toxocara spp. eggs. The Sanger sequence was used to differentiate the Toxocara species. Subsequently, all the sequenced data were blasted and compared with other sequences available in the GenBank. Results Out of 240 soil samples collected, 7 (2.9%) samples were identified to contain Toxocara spp. eggs using Sheather's flotation and microscopic techniques. Meanwhile, 19 (7.9%) samples were positive using nested PCR. According to the Sanger sequencing analysis findings, all positive samples were contaminated with Toxocara cati. Conclusion As evidenced by the obtained results, only T. cati species were detected in public parks and playgrounds in Zahedan; therefore, control and prevention programs against this species should be considered in human and animal communities.
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Affiliation(s)
- Siavash Liravizadeh
- Department of Parasitology and MycologyFaculty of MedicineZahedan University of Medical Sciences, Zahedan, Iran
| | - Samaneh Abdolahi Khabisi
- Department of Parasitology and MycologyFaculty of MedicineZahedan University of Medical Sciences, Zahedan, Iran
| | - Alireza Salimi Khorashad
- Department of Parasitology and MycologyFaculty of MedicineZahedan University of Medical Sciences, Zahedan, Iran
| | - Hadi Mirahmadi
- Department of Parasitology and MycologyFaculty of MedicineZahedan University of Medical Sciences, Zahedan, Iran
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Haleche I, Guilane A, Boutellis A, Medrouh B, Saidi F, Kernif T, Ziam H. Microscopic and molecular prevalence and associated risk factors with Toxocara and Blastocystis infection in dogs and cats in Mitidja, Algeria. Parasitol Res 2024; 123:216. [PMID: 38771352 DOI: 10.1007/s00436-024-08240-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 05/14/2024] [Indexed: 05/22/2024]
Abstract
Domestic dogs and cats can serve as a source of environmental contamination with Toxocara spp. and Blastocystis spp., and this represents a neglected public and veterinary health problem. We assessed the microscopic and molecular prevalence of these species in a locality in Algeria and identified the associated risk factors. The faeces of 225 dogs and 78 cats were collected in Mitidja between March and July 2022. The samples were analysed by coproscopy and by polymerase chain reaction (PCR) targeting the Internal Transcribed Spacer 2 (ITS2) and Small Subunit Ribosomal (SSU-RNA) of T. canis and Blastocystis spp. respectively. The overall microscopic prevalence of Toxocara spp. in dogs and cats was 9.78 ± 1.98% and 12.82 ± 7.42%, respectively. The rate of Blastocystis spp. was 15.11 ± 2.39% and 15.38 ± 4.08% in dogs and cats, respectively while the molecular prevalence of T. canis in dogs was 4.89 ± 1.44% and in cats 1.28 ± 1.27%; the prevalence of Blastocystis spp. was 41.78 ± 3.29% and 34.62 ± 5.39% in dogs and cats, respectively. Phylogenetic and phylogeographic analyses identified the presence of the H1 subtype of T. canis in dogs, and the ST1 subtype of Blastocystis in dogs and cats. Dogs with clinical signs were more likely to be infected with T. canis (OR 6.039, P < 0.05) than healthy dogs. This study demonstrates that dogs and cats are carriers of Toxocara spp. and Blastocystis spp. and are therefore a source of environmental contamination. Veterinarians and human health professionals should work together to implement control strategies as part of a "One Health" approach to improving animal health and reducing the risk of transmission to humans.
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Affiliation(s)
- Ikram Haleche
- Laboratory of Biotechnology, Environment and Health, University of Blida 1, Blida, Algeria
- Laboratory of Parasitic Eco-epidemiology and Population Genetics, Pasteur Institute of Algeria, Dely Brahim, Algiers, Algeria
| | - Asma Guilane
- Laboratory of Parasitic Eco-epidemiology and Population Genetics, Pasteur Institute of Algeria, Dely Brahim, Algiers, Algeria
- Laboratoire de Biodiversité et Environnement: Interaction, Génome, Faculté des Sciences Biologiques, Université des Sciences et de la Technologie Houari Boumediene, Alger, Algeria
| | - Amina Boutellis
- Laboratoire de Biodiversité et Environnement: Interaction, Génome, Faculté des Sciences Biologiques, Université des Sciences et de la Technologie Houari Boumediene, Alger, Algeria
| | - Bachir Medrouh
- Center of Research in Agro-Pastoralism, 17000, Djelfa, Algeria
| | - Fairouz Saidi
- Laboratory of Biotechnology, Environment and Health, University of Blida 1, Blida, Algeria
| | - Tahar Kernif
- Laboratory of Parasitic Eco-epidemiology and Population Genetics, Pasteur Institute of Algeria, Dely Brahim, Algiers, Algeria
| | - Hocine Ziam
- Laboratory of Biotechnology, Environment and Health, University of Blida 1, Blida, Algeria.
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Cai W, Zhu Y, Wang F, Feng Q, Zhang Z, Xue N, Xu X, Hou Z, Liu D, Xu J, Tao J. Prevalence of Gastrointestinal Parasites in Zoo Animals and Phylogenetic Characterization of Toxascaris leonina (Linstow, 1902) and Baylisascaris transfuga (Rudolphi, 1819) in Jiangsu Province, Eastern China. Animals (Basel) 2024; 14:375. [PMID: 38338018 PMCID: PMC10854492 DOI: 10.3390/ani14030375] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/12/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
The burden of gastrointestinal parasites in zoo animals has serious implications for their welfare and the health of veterinarians and visitors. Zhuyuwan Zoo is located in the eastern suburb of Yangzhou city in eastern China, in which over 40 species of zoo animals are kept. In order to understand the infection status of GI parasites in Zhuyuwan Zoo, a total of 104 fresh fecal samples collected randomly from birds (n = 19), primates (n = 19), and non-primate mammals (n = 66) were analyzed using the saturated saline flotation technique and nylon sifter elutriation and sieving method for eggs/oocysts, respectively. Two Ascaris species were molecularly characterized. The results showed that the overall prevalence of parasitic infection was 42.3% (44/104). The parasitic infection rate in birds, primates, and non-primate mammals were 26.3% (5/19), 31.6% (6/19), and 50.0% (33/66), respectively. A total of 11 species of parasites were identified, namely, Trichostrongylidae, Capillaria sp., Trichuris spp., Strongyloides spp., Amidostomum sp., Toxascaris leonina, Baylisascaris transfuga, Parascaris equorum, Paramphistomum spp., Fasciola spp., and Eimeria spp. Paramphistomum spp. eggs were first detected from the captive Père David's deer, and Fasciola spp. eggs were first reported from sika deer in zoo in China. A sequence analysis of ITS-2 and cox1 showed that the eggs isolated from the African lion (Panthera leo Linnaeus, 1758) were T. leonina, and the eggs from the brown bear (Ursus arctos Linnaeus, 1758) were B. transfuga. The public health threat posed by these potential zoonotic parasitic agents requires attention. These results lay a theoretical foundation for prevention and control of wild animal parasitic diseases at zoos in China.
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Affiliation(s)
- Weimin Cai
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (W.C.); (Y.Z.); (F.W.); (Q.F.); (Z.Z.); (N.X.); (Z.H.); (D.L.); (J.X.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Yu Zhu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (W.C.); (Y.Z.); (F.W.); (Q.F.); (Z.Z.); (N.X.); (Z.H.); (D.L.); (J.X.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Feiyan Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (W.C.); (Y.Z.); (F.W.); (Q.F.); (Z.Z.); (N.X.); (Z.H.); (D.L.); (J.X.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Qianqian Feng
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (W.C.); (Y.Z.); (F.W.); (Q.F.); (Z.Z.); (N.X.); (Z.H.); (D.L.); (J.X.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Zhizhi Zhang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (W.C.); (Y.Z.); (F.W.); (Q.F.); (Z.Z.); (N.X.); (Z.H.); (D.L.); (J.X.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Nianyu Xue
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (W.C.); (Y.Z.); (F.W.); (Q.F.); (Z.Z.); (N.X.); (Z.H.); (D.L.); (J.X.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Xun Xu
- Yangzhou Zhuyuwan Zoo, Yangzhou 225009, China;
| | - Zhaofeng Hou
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (W.C.); (Y.Z.); (F.W.); (Q.F.); (Z.Z.); (N.X.); (Z.H.); (D.L.); (J.X.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Dandan Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (W.C.); (Y.Z.); (F.W.); (Q.F.); (Z.Z.); (N.X.); (Z.H.); (D.L.); (J.X.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Jinjun Xu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (W.C.); (Y.Z.); (F.W.); (Q.F.); (Z.Z.); (N.X.); (Z.H.); (D.L.); (J.X.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Jianping Tao
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (W.C.); (Y.Z.); (F.W.); (Q.F.); (Z.Z.); (N.X.); (Z.H.); (D.L.); (J.X.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
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Attia MM, Mosallam T, Samir O, Ali A, Samir A. Toxascaris leonina infected domestic cat ( Felis catus) in Egypt; PCR-based molecular characterization of nematode eggs: a potential hazards to human health. J Parasit Dis 2023; 47:843-849. [PMID: 38009147 PMCID: PMC10667188 DOI: 10.1007/s12639-023-01631-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 10/22/2023] [Indexed: 11/28/2023] Open
Abstract
This molecular-epidemiological study was conducted in several locations in Cairo and Giza Governorates in domestic cats (Felis catus) to detect the most common intestinal helminths in feces and molecularly characterize this nematode. So, three hundred domestic cats were admitted to different clinics around Cairo and Giza Governorates with severe diarrhea, even watery, between January 2023 and April 2023. The ages of the cats ranged from 1 to 2.5 years old. Blood, sera, and urine samples were collected for further investigation of the health condition of the animals. Toxascaris leonina was the major intestinal parasite found in cat stools, with a prevalence rate of 5% (15 cats). Toxascaris leonina (T. leonina) eggs had oval elliptical surfaces and thick cuticles. An embryo was located inside the smooth outer shell wall of the shell. The animals suffer from normocytic normochromic anemia with leukocytosis, relative lymphocytosis, and thrombocytopenia. The amplification of the ITS-rDNA region from the ascaridoid nematodes was successfully performed using NC5 and NC2 primers. The PCR product of the ITS-rDNA fragment was sequenced and yielded 860 bp. The accession number of the sequenced ITS-rDNA region was OQ735413, submitted to Gene Bank, and based on the blast analysis of NCBI, the current ascaridoid nematode proved to be genetically related to the family Ascarididae and identified as T. leonina.
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Affiliation(s)
- Marwa M. Attia
- Department of Parasitology, Faculty of Veterinary Medicine, Cairo University, Giza, 12211 Egypt
| | - Tarek Mosallam
- Animal Reproductive Research Institute, Haram, Giza, Egypt
| | - Ojena Samir
- LeptoVet Lab for Veterinary Diagnostic Services, Garden City, Egypt
| | - Aisha Ali
- LeptoVet Lab for Veterinary Diagnostic Services, Garden City, Egypt
| | - Ahmed Samir
- Department of Microbiology, Faculty of Veterinary Medicine, Cairo University, Giza, 12211 Egypt
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Henke K, Ntovas S, Xourgia E, Exadaktylos AK, Klukowska-Rötzler J, Ziaka M. Who Let the Dogs Out? Unmasking the Neglected: A Semi-Systematic Review on the Enduring Impact of Toxocariasis, a Prevalent Zoonotic Infection. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:6972. [PMID: 37947530 PMCID: PMC10649795 DOI: 10.3390/ijerph20216972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 09/28/2023] [Accepted: 10/17/2023] [Indexed: 11/12/2023]
Abstract
Toxocariasis remains an important neglected parasitic infection representing one of the most common zoonotic infections caused by the parasite Toxocara canis or, less frequently, by Toxocara cati. The epidemiology of the disease is complex due to its transmission route by accidental ingestion of embryonated Toxocara eggs or larvae from tissues from domestic or wild paratenic hosts. Even though the World Health Organization and Centers for Disease Control classified toxocariasis amongst the top six parasitic infections of priority to public health, global epidemiological data regarding the relationship between seropositivity and toxocariasis is limited. Although the vast majority of the infected individuals remain asymptomatic or experience a mild disease, the infection is associated with important health and socioeconomic consequences, particularly in underprivileged, tropical, and subtropical areas. Toxocariasis is a disease with multiple clinical presentations, which are classified into five distinct forms: the classical visceral larva migrans, ocular toxocariasis, common toxocariasis, covert toxocariasis, and cerebral toxocariasis or neurotoxocariasis. Anthelmintic agents, for example, albendazole or mebendazole, are the recommended treatment, whereas a combination with topical or systemic corticosteroids for specific forms is suggested. Prevention strategies include educational programs, behavioral and hygienic changes, enhancement of the role of veterinarians, and anthelmintic regimens to control active infections.
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Affiliation(s)
- Katrin Henke
- Department of Internal Medicine, Thun Hospital, Krankenhausstrasse 12, 3600 Thun, Switzerland;
- Department of Emergency Medicine, Inselspital, University Hospital, University of Bern, 3008 Bern, Switzerland; (S.N.); (A.K.E.); (J.K.-R.)
| | - Sotirios Ntovas
- Department of Emergency Medicine, Inselspital, University Hospital, University of Bern, 3008 Bern, Switzerland; (S.N.); (A.K.E.); (J.K.-R.)
- Department of Visceral Surgery and Medicine, lnselspital, University Hospital, University of Bern, 3008 Bern, Switzerland
| | - Eleni Xourgia
- Department of Heart Surgery, lnselspital, University Hospital, University of Bern, 3008 Bern, Switzerland;
| | - Aristomenis K. Exadaktylos
- Department of Emergency Medicine, Inselspital, University Hospital, University of Bern, 3008 Bern, Switzerland; (S.N.); (A.K.E.); (J.K.-R.)
| | - Jolanta Klukowska-Rötzler
- Department of Emergency Medicine, Inselspital, University Hospital, University of Bern, 3008 Bern, Switzerland; (S.N.); (A.K.E.); (J.K.-R.)
| | - Mairi Ziaka
- Department of Internal Medicine, Thun Hospital, Krankenhausstrasse 12, 3600 Thun, Switzerland;
- Department of Emergency Medicine, Inselspital, University Hospital, University of Bern, 3008 Bern, Switzerland; (S.N.); (A.K.E.); (J.K.-R.)
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Zendejas-Heredia PA, Colella V, Huggins LG, Schaper R, Schunack B, Traub RJ. An Integrated Coproscopic and Molecular Method Provides Insights into the Epidemiology of Zoonotic Intestinal Helminths of Dogs across Cambodia. Transbound Emerg Dis 2023; 2023:2001871. [PMID: 40303737 PMCID: PMC12016947 DOI: 10.1155/2023/2001871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 07/14/2023] [Accepted: 07/17/2023] [Indexed: 05/02/2025]
Abstract
Introduction In Cambodia, a limited number of focal surveys targeting dogs in rural communities have reported intestinal helminths of potential zoonotic risk as highly endemic. In this study, we investigated the prevalence, diversity, distribution, and risk predictors associated with zoonotic intestinal helminths infecting pet, community, and pagoda dogs across rural and urban settings in Cambodia through an integrated coproscopic and molecular approach. Methods Faecal samples, demographic, and clinical data were collected from 457 dogs across Cambodia. Faeces were screened for gastroenteric parasites using sodium nitrate faecal floatation (1.30 SpGr) and multiplex TaqMan-based quantitative polymerase chain reaction (qPCR) assays for differentiation of canine hookworm species (Ancylostoma ceylanicum, Ancylostoma braziliense, Ancylostoma caninum, and Uncinaria stenocephala) and for Strongyloides spp. Conventional polymerase chain reaction (PCR) and DNA sequencing was used to further characterise eggs resembling zoonotic helminths that could not be designated to a species level by light microscopy alone. In addition, infection intensities for hookworms and Toxocara as eggs per gram of faeces were estimated to assess the dog age-dependent contribution of these zoonotic parasites in the environment. Finally, multiple logistic regression analyses were performed to identify risk predictors for gastrointestinal parasitoses. Results Using combined coproscopic and molecular methods, we detected at least one helminth in 79% of the sampled dogs. Of these, 78.8% were infected with at least one zoonotic species, with A. ceylanicum (50%) and A. caninum (50%) constituting the most common parasites followed by A. braziliense (20%), Toxocara canis (15%), Strongyloides spp. (5%), Dipylidium caninum (2%), and Eucoleus spp. (2%). The indirect zoonotic helminths Spirometra erinaceieuropaei, Spirometra mansoni, and Haplorchis yokogawai contributed to 14% of the total infections in dogs. Dogs were also found mechanically passing eggs of large trematodes such as Fischoederius elongatus, Schistosoma spp., Paramphistomatidae, and Gastrothylax crumenifer. Contradictory to previous reports, the prevalence of T. canis was highest in adult dogs with egg shedding intensity peaking in dogs more than 7 years of age. Finally, we found that pale mucous membranes and low total protein were predictors of hookworm infection in dogs (p < 0.05). Conclusion Dogs within both rural and urban settings across Cambodia are highly infected with a large diversity of zoonotic gastroenteric helminths. This study reports the presence of A. braziliense, the aetiological agent of hookworm-related "creeping eruptions" for the first time in Cambodia. Moreover, infection intensity data suggest that adult dogs should also be targeted by deworming campaigns to reduce the prevalence of zoonotic hookworm and T. canis infections within the country. These results highlight the need for an integrated approach to canine population management and parasite control in dogs across urban and rural settings in Cambodia to mitigate the public health risks and impacts posed by these helminths.
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Affiliation(s)
| | - Vito Colella
- Faculty of Science, University of Melbourne, Parkville, Victoria, Australia
| | - Lucas G. Huggins
- Faculty of Science, University of Melbourne, Parkville, Victoria, Australia
| | - Roland Schaper
- Bayer Animal Health GmbH An Elanco Company, Monheim, Germany
| | | | - Rebecca J. Traub
- Faculty of Science, University of Melbourne, Parkville, Victoria, Australia
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Macpherson ML, Zendejas-Heredia PA, Sylvester W, Gasser RB, Traub RJ, Colella V, Macpherson CN. Zoonotic helminths of dogs and risk factors associated with polyparasitism in Grenada, West Indies. Parasitology 2023; 150:754-759. [PMID: 37184089 PMCID: PMC10410397 DOI: 10.1017/s0031182023000495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 05/02/2023] [Accepted: 05/03/2023] [Indexed: 05/16/2023]
Abstract
Canine soil-transmitted helminths (STHs) cause important zoonoses in the tropics, with varying degrees of intensity of infection in humans and dogs. This study aimed to investigate the prevalence and associated risk factors for STHs in community dogs residing in Grenada, West Indies. In May 2021, 232 canine fecal samples were examined for zoonotic helminths by microscopy (following flotation), and genomic DNA from a subset of 211 of these samples were subjected to multiplex qPCR for the detection and specific identification of hookworms, Toxocara spp. and Strongyloides. Microscopic examination revealed that 46.5% (108/232, 95% CI 40–52.9), 9% (21/232, 95% CI 5.35–12.7) and 5.2% (12/232, 95% CI 2.3–8) of the samples contained eggs of Ancylostoma spp., Toxocara spp. and Trichuris vulpis, respectively. Multiplex qPCR revealed that, 42.2% (89/211, 95% CI 35.5–48.8) were positive for at least 1 zoonotic parasite. Of these, 40.8% (86/211, 95% CI 34.1–47.3) of samples tested positive for Ancylostoma spp., 36% (76/211, 95% CI 29.5–42.9) were positive for A. caninum, 13.3% (28/211, 95% CI 9–18.6) for A. ceylanicum, 5.7% for T. canis (12/211, 95% CI 2.97–8.81) and 1% (2/211, 95% CI 0–2.26) for Strongyloides spp. (identified as S. stercoralis and S. papillosus by conventional PCR-based Sanger sequencing). Using a multiple logistic regression model, a low body score and free-roaming behaviour were significant predictors of test-positivity for these parasitic nematodes in dogs (P < 0.05). Further studies of zoonotic STHs in humans should help elucidate the public health relevance of these parasites in Grenada.
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Affiliation(s)
- Maxine L.A. Macpherson
- Windward Islands Research and Education Foundation, St. George's, Grenada, West Indies
- School of Veterinary Medicine, St. George's University, St. George's, Grenada, West Indies
| | | | - Wayne Sylvester
- Windward Islands Research and Education Foundation, St. George's, Grenada, West Indies
- School of Veterinary Medicine, St. George's University, St. George's, Grenada, West Indies
| | - Robin B. Gasser
- Faculty of Science, Melbourne Veterinary School, University of Melbourne, Parkville, VIC, Australia
| | - Rebecca J. Traub
- Faculty of Science, Melbourne Veterinary School, University of Melbourne, Parkville, VIC, Australia
| | - Vito Colella
- Faculty of Science, Melbourne Veterinary School, University of Melbourne, Parkville, VIC, Australia
| | - Calum N.L. Macpherson
- Windward Islands Research and Education Foundation, St. George's, Grenada, West Indies
- School of Veterinary Medicine, St. George's University, St. George's, Grenada, West Indies
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9
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Shokri E, Haniloo A, Zibaei M, Pezeshki A, Mansori K, Taira K. Detection of Toxocara species larvae in four Iranian free-range broiler farms. BMC Vet Res 2022; 18:413. [PMID: 36411453 PMCID: PMC9680124 DOI: 10.1186/s12917-022-03516-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Accepted: 11/11/2022] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND The epidemiology of Toxocara canis and Toxocara cati in food animals, associated products, and their zoonotic potential are poorly understood. A cross sectional study was designed to determine the prevalence of Toxocara spp. larvae from free-range broiler chickens in traditional farms using conventional techniques and molecular method. Eight-hundred tissue samples including liver, gizzard, lungs and heart were collected from 200 chickens belonging to different regions of Zanjan Province, Iran and were processed by conventional and molecular methods. RESULTS Out of 800 chicken tissues, 49 samples (6.1%) were positive for nematode larvae. Polymerase chain reaction was performed to identify species-specific of Toxocara larvae. The findings showed that 10.5% (21 out of 200) chickens were infected with Toxocara species, so that 57.1% (12 out of 21) of the samples were positive for Toxocara canis and 42.9% (9 out of 21) of the samples were positive for Toxocara cati. CONCLUSION Considering the significant contamination/infection of free-range broiler chickens with Toxocara larvae, the consumption of chicken meat and viscera, especially liver and gizzards, can play an important role in the transmission of infection to humans. Prevention and control measures focused on regular deworming of dogs and cats, increasing public awareness of Toxocara infection are recommended.
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Affiliation(s)
- Elham Shokri
- grid.469309.10000 0004 0612 8427Department of Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Ali Haniloo
- grid.469309.10000 0004 0612 8427Department of Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Mohammad Zibaei
- grid.411705.60000 0001 0166 0922Department of Parasitology and Mycology, School of Medicine, Alborz University of Medical Sciences, P.O. Box: 3149779453, Karaj, Iran
| | - Ali Pezeshki
- grid.469309.10000 0004 0612 8427Department of Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Kamyar Mansori
- grid.469309.10000 0004 0612 8427Department of Epidemiology and Biostatistics, School of Medicine, Zanjan University of Medical Sciences, Karaj, Iran
| | - Kensuke Taira
- grid.252643.40000 0001 0029 6233Laboratory of Parasitology, School of Veterinary Medicine, Azabu University, Fuchinobe, Sagamihara, Kanagawa Japan
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10
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Zhang X, Jian Y, Ma Y, Li Z, Fu Y, Cairang Z, Wang X, Duo H, Guo Z. Prevalence of Intestinal Parasites in Dog Faecal Samples from Public Environments in Qinghai Province, China. Pathogens 2022; 11:1240. [PMID: 36364990 PMCID: PMC9696243 DOI: 10.3390/pathogens11111240] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/23/2022] [Accepted: 10/24/2022] [Indexed: 01/03/2024] Open
Abstract
Dogs are popular companions in our daily lives for company, hunting, protection or shepherding, but they also serve as reservoirs for zoonotic parasites. We analysed faecal samples from urban and rural environments in Qinghai Province on the Qinghai-Tibet Plateau of China to determine the prevalence of intestinal parasites. A total of 682 faecal samples were collected from four urban and two rural environments from October 2019 to December 2020. The samples were analysed for common intestinal parasites using a species-specific PCR approach. The total number of samples with parasites was 40 (5.87%): 23 (3.37%) were positive for helminths, and 17 (2.49%) were positive for protozoa. The following parasites were identified, and their respective prevalence rates were calculated: Cryptosporidium canis (1.32%), Giardia duodenalis (1.17%, assemblages D (n = 6) and C (n = 2)), Taenia hydatigena (1.03%), Taenia multiceps (0.59%), Toxocara canis (0.59%), Echinococcus shiquicus (0.29%), Dipylidium caninum (0.29%), Taenia pisiformis (0.15%), Mesocestoides lineatus (0.15%), Trichuris vulpis (0.15%), and Ancylostoma spp. (0.15%). The overall prevalence was significantly higher in dog faecal samples from rural environments than in those from urban environments (16.19% vs. 3.99%). E. shiquicus, T. pisiformis, M. lineatus, T. vulpis, and Ancylostoma spp. were only found in dog faecal samples from rural environments. The results of the present study indicate that intestinal parasite-positive dogs are important sources of environmental contamination, suggesting a significant zoonotic infection risk in humans and other animals. This has implications for the ongoing control of intestinal parasite infections in dogs in Qinghai Province, China.
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Affiliation(s)
- Xueyong Zhang
- Qinghai Academy of Animal Sciences and Veterinary Medicine, Qinghai University, Xining 810016, China
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China
| | - Yingna Jian
- Qinghai Academy of Animal Sciences and Veterinary Medicine, Qinghai University, Xining 810016, China
| | - Yijuan Ma
- Qinghai Academy of Animal Sciences and Veterinary Medicine, Qinghai University, Xining 810016, China
| | - Zhi Li
- Qinghai Academy of Animal Sciences and Veterinary Medicine, Qinghai University, Xining 810016, China
| | - Yong Fu
- Qinghai Academy of Animal Sciences and Veterinary Medicine, Qinghai University, Xining 810016, China
| | - Zhouzai Cairang
- Gangcha County Animal Husbandry and Veterinary Station, Haibei 812399, China
| | - Xiaohong Wang
- Guinan County Animal Husbandry and Veterinary Station, Hainan 813100, China
| | - Hong Duo
- Qinghai Academy of Animal Sciences and Veterinary Medicine, Qinghai University, Xining 810016, China
| | - Zhihong Guo
- Qinghai Academy of Animal Sciences and Veterinary Medicine, Qinghai University, Xining 810016, China
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11
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Maciag L, Morgan ER, Holland C. Toxocara: time to let cati ‘out of the bag’. Trends Parasitol 2022; 38:280-289. [DOI: 10.1016/j.pt.2021.12.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/04/2021] [Accepted: 12/20/2021] [Indexed: 12/22/2022]
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12
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A review of molecular identification tools for the opisthorchioidea. J Microbiol Methods 2021; 187:106258. [PMID: 34082051 DOI: 10.1016/j.mimet.2021.106258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 05/28/2021] [Accepted: 05/28/2021] [Indexed: 11/23/2022]
Abstract
The superfamily Opisthorchioidea encompasses the families Cryptogonimidae, Opisthorchiidae and Heterophyidae. These parasites depend on the aquatic environment and include marine and freshwater species. Some species, such as Clonorchis sinensis and Opisthorchis viverrini, have a high impact on public health with millions of infected people worldwide and have thus been the object of many studies and tool developments. However, for many species, tools for identification and detection are scarce. Although morphological descriptions have been used and are still important, they are often not efficient on the immature stages of these parasites. Thus, during the past few decades, molecular approaches for parasite identification have become commonplace. These approaches are efficient, quick and reliable. Nonetheless, for some parasites of the superfamily Opisthorchioidea, reference genomic data are limited. This study reviews available genetic data and molecular tools for the identification and/or the detection of this superfamily. Molecular data on this superfamily are mostly based on mitochondrial and ribosomal gene sequence analyses, especially on the cytochrome c oxidase subunit 1 gene and internal transcribed spacer regions respectively.
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13
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Avila HG, Risso MG, Ruybal P, Repetto SA, Butti MJ, Trangoni MD, Grune Löffler S, Pérez VM, Periago MV. Development of a low-cost copro-LAMP assay for simultaneous copro-detection of Toxocara canis and Toxocara cati. Parasitology 2021; 148:819-826. [PMID: 33593468 PMCID: PMC11010131 DOI: 10.1017/s0031182021000342] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/02/2021] [Accepted: 02/13/2021] [Indexed: 11/06/2022]
Abstract
Toxocariasis is a zoonotic disease caused mainly by Toxocara canis and Toxocara cati and diagnosis in dogs and cats is an important tool for its control. For this reason, a new coprological loop-mediated isothermal amplification (LAMP) assay was developed for the simultaneous detection of these species. The primer set was designed on a region of the mitochondrial cox-1 gene. Amplification conditions were evaluated using a temperature gradient (52°C to 68°C), different incubation times (15–120 min), and different concentrations of malachite green dye (0.004–0.4% w/v). The analytical sensitivity was evaluated with serial dilutions of genomic DNA from T. canis and T. cati adult worms, and with serial dilutions of DNA extracted from feces using a low-cost in-house method. The specificity was evaluated using genomic DNA from Canis lupus familiaris, Felis catus, Escherichia coli, Toxascaris leonina, Ancylostoma caninum, Echinococcus granulosus sensu stricto and Taenia hydatigena. The LAMP assay applied to environmental fecal samples from an endemic area showed an analytical sensitivity of 10–100 fg of genomic DNA and 10−5 serial dilutions of DNA extracted from feces using the low-cost in-house method; with a specificity of 100%. Additionally, the total development of the assay was carried out in a basic laboratory and per-reaction reagent cost decreased by ~80%. This new, low-cost tool can help identify the most common agents of toxocariasis in endemic areas in order to manage prevention strategies without having to rely on a laboratory with sophisticated equipment.
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Affiliation(s)
- Héctor Gabriel Avila
- Laboratorio Provincial de Zoonosis de San Juan, Facultad de Ciencias Veterinarias, Facultad de Ciencias Químicas y Tecnológicas, Universidad Católica de Cuyo, San Luis, San Juan, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, CABA, Argentina
| | - Marikena Guadalupe Risso
- Instituto de Investigaciones en Microbiología y Parasitología Médica, IMPAM-UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, CABA, Argentina
| | - Paula Ruybal
- Instituto de Investigaciones en Microbiología y Parasitología Médica, IMPAM-UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, CABA, Argentina
| | - Silvia Analía Repetto
- Instituto de Investigaciones en Microbiología y Parasitología Médica, IMPAM-UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, CABA, Argentina
| | - Marcos Javier Butti
- Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias, Cátedra de Parasitología Comparada, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Buenos Aires, Argentina
| | - Marcos David Trangoni
- Laboratorio de Brucella, Campylobacter y Microbiota del rumen, Instituto de Biotecnología/Instituto de Agrobiotecnología y Biología Molecular (IB/IABIMO), UEDD INTA-CONICET, CICVyA, CNIA, INTA Castelar, Hurlingham, Buenos Aires, Argentina
| | - Sylvia Grune Löffler
- Laboratorio de Leptospirosis, Instituto de Patobiología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnología Agropecuaria Castelar, Buenos Aires, Argentina
| | - Verónica Mirtha Pérez
- Sección de Rabia y Zoonosis, Dirección de Epidemiología, Ministerio de Salud Pública de San Juan, San Juan, Argentina
| | - María Victoria Periago
- Consejo Nacional de Investigaciones Científicas y Técnicas, CABA, Argentina
- Fundación Mundo Sano, Buenos Aires, Argentina
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14
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Li H, Liu Y, Wang C, Li Y, Chen Y, Wang L, Zhou X, Xie Y. The complete mitogenome of Toxascaris leonina from the Siberian tiger ( Panthera tigris altaica). MITOCHONDRIAL DNA PART B-RESOURCES 2021; 6:1416-1418. [PMID: 33948494 PMCID: PMC8057085 DOI: 10.1080/23802359.2021.1911713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Toxascaris leonina is a polyxenical parasite and commonly found in canids and felids. In this study, we used the Illumina high throughput sequencing and assembly to determine the complete mitogenome of a representative of this parasite from the Siberian tiger (Panthera tigris altaica). The genome was 14,248 bp in size and encoded 12 protein-coding genes, 22 transfer RNAs, and two ribosomal RNAs. Phylogeny showed that two canid (dog)-originated T. leonina were phylogenetically distinct from two felid-originated T. leonina (tiger isolate and cheetah isolate), suggesting at least two distinct subclades of T. leonina infecting these hosts and supporting once again that T. leonina represents a species complex. Furthermore, four isolates of T. leonina grouped together and were more closely related to other species from the family Ascarididae than species of families Toxocaridae, Anisakidae and Ascaridiidae, demonstrating phylogenetic stability of these paraphyletic groups characterized in this study. These cumulative mitochondrial DNA data provide a better understanding of phylogenetic relationships of this polyxenical and zoonotic roundworm species.
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Affiliation(s)
- Hongyu Li
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yunjian Liu
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Chengdong Wang
- China Conservation and Research Center for Giant Panda, Wolong, China
| | - Yingxin Li
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yijun Chen
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Lidan Wang
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xuan Zhou
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Yue Xie
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
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15
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Xie Y, Li Y, Gu X, Liu Y, Zhou X, Wang L, He R, Peng X, Yang G. Molecular characterization of ascaridoid parasites from captive wild carnivores in China using ribosomal and mitochondrial sequences. Parasit Vectors 2020; 13:382. [PMID: 32727607 PMCID: PMC7391581 DOI: 10.1186/s13071-020-04254-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 07/21/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Despite the public health importance of toxocariasis/toxascariasis, only a few species of these ascaridoid parasites from wild canine and feline carnivores have been studied at the molecular level so far. Poor understanding of diversity, host distribution and the potential (zoonotic) transmission of the ascaridoid species among wild animals negatively affects their surveillance and control in natural settings. In this study, we updated previous knowledge by profiling the genetic diversity and phylogenetic relationships of ascaridoid species among eleven wild canine and feline animals on the basis of a combined analysis of the ribosomal internal transcribed spacer region (ITS) gene and the partial mitochondrial cytochrome c oxidase subunit 2 (cox2) and NADH dehydrogenase subunit 1 (nad1) genes. RESULTS In total, three genetically distinct ascaridoid lineages were determined to be present among these wild carnivores sampled, including Toxocara canis in Alopex lagopus and Vulpes vulpes, Toxocara cati in Felis chaus, Prionailurus bengalensis and Catopuma temmincki and Toxascaris leonina in Canis lupus, Panthera tigris altaica, Panthera tigris amoyensis, Panthera tigris tigris, Panthera leo and Lynx lynx. Furthermore, it was evident that T. leonina lineage split into three well-supported subclades depending on their host species, i.e. wild felids, dogs and wolves and foxes, based on integrated genetic and phylogenetic evidence, supporting that a complex of T. leonina other than one species infecting these hosts. CONCLUSIONS These results provide new molecular insights into classification, phylogenetic relationships and epidemiological importance of ascaridoids from wild canids and felids and also highlight the complex of the taxonomy and genetics of Toxascaris in their wild and domestic carnivorous hosts.
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Affiliation(s)
- Yue Xie
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.
| | - Yingxin Li
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xiaobin Gu
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yunjian Liu
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xuan Zhou
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Lu Wang
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Ran He
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xuerong Peng
- Department of Chemistry, College of Life and Basic Science, Sichuan Agricultural University, Chengdu, 611130, China
| | - Guangyou Yang
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.
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16
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French AF, Castillo-Alcala F, Gedye KR, Roe WD, Gartrell BD. Nematode larva migrans caused by Toxocara cati in the North Island brown kiwi ( Apteryx mantelli). INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2020; 11:221-228. [PMID: 32181127 PMCID: PMC7066032 DOI: 10.1016/j.ijppaw.2020.02.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/19/2020] [Accepted: 02/20/2020] [Indexed: 11/12/2022]
Abstract
Sporadic cases of visceral and neural nematode larva migrans have been diagnosed at necropsy in the endangered New Zealand kiwi (Apteryx spp.), but the causative organisms have not yet been definitively identified. From an initial group of five affected kiwi, PCR was performed on DNA extracted from archival formalin-fixed paraffin-embedded tissue sections in which larval nematodes had been histologically identified. Sequencing of positive results from four out of the five kiwi aligned with sequences from Toxocara cati, a nematode parasite whose definitive host is the domestic cat. PCR was then performed on a second group of 12 kiwi that had histologic inflammatory lesions consistent with larva migrans, but variable larval presence. Repeatable positive PCR results were only achieved in one tissue, in which larval organisms were histologically confirmed. This study supports the use of PCR as an alternative or adjunct to the morphological identification of nematode larvae in formalin-fixed histopathological samples, as well as showing that in investigation of larva migrans, PCR has greatest chance of success from sections where nematode larvae are evident histologically. The identification of Toxocara cati from lesions of larva migrans in kiwi reflects an indirect, parasite-mediated effect of an invasive mammalian species on a native species. Cases of nematode larva migrans have been diagnosed in the New Zealand kiwi. PCR was performed on archival formalin-fixed paraffin-embedded tissue blocks. Results identified Toxocara cati, a parasite of cats, as the causative agent. PCR had greatest success from tissues where larvae were identifiable histologically.
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Affiliation(s)
- Adrienne F French
- School of Veterinary Science, Massey University, Private Bag 11-222, Palmerston North, New Zealand
| | - Fernanda Castillo-Alcala
- School of Veterinary Science, Massey University, Private Bag 11-222, Palmerston North, New Zealand
| | - Kristene R Gedye
- School of Veterinary Science, Massey University, Private Bag 11-222, Palmerston North, New Zealand
| | - Wendi D Roe
- School of Veterinary Science, Massey University, Private Bag 11-222, Palmerston North, New Zealand
| | - Brett D Gartrell
- School of Veterinary Science, Massey University, Private Bag 11-222, Palmerston North, New Zealand
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Abstract
Toxocariasis is a worldwide-distributed helminthic zoonosis, which mainly results from ascarid nematodes Toxocara canis and Toxocara cati. Humans become infected by accidental ingestion of infective eggs, raw or undercooked meat containing larvae. Keeping and contacting cats and dogs, and bad hygiene situations or habits are the main risk factors for Toxocara infection in China. The seroprevalence of Toxocara spp. is reported from 12.14% to 44.83%, and the overall seroprevalence in children was 12.14% in 1993 and elevated to 19.3% in 2015. Among the 103 cases reported in China during 1983-2019, ocular larva migrans (OLM), visceral larva migrans (VLM), and neural larva migrans (NLM) occupied 92.23%, 6.80%, and 0.97% of cases, respectively. The diagnosis of toxocariasis is mainly based on the history of exposure to infective eggs or larvae, clinical manifestations, laboratory examinations, and imaging studies. As most individuals who are infected with larval Toxocara, are unaware of their infections, patients with mild signs as described under covert toxocariasis (CT) can recover spontaneously, and treatment may not be necessary. Albendazole is the preferred treatment for patients with VLM; steroids, such as prednisolone combined with albendazole, are frequently used in treating patients with OLM, and surgery serves as an alternative treatment; thiabendazole is effective in treating patients with NLM. The true number of cases and prevalence of toxocariasis in China seems to be underestimated and neglected because of the lack of population-based epidemiological studies and insufficient clinical awareness of this disease, which are aspects that need to be improved by the Chinese government.
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Affiliation(s)
- Ling Kong
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Hong-Juan Peng
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China.
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Rasouli E, Zibaei M, Bahadory S, Hosseini H, Firoozeh F. Parasitological and molecular study of Toxocara spp. in Lumbericus terrestricus earthworms. BULGARIAN JOURNAL OF VETERINARY MEDICINE 2020. [DOI: 10.15547/bjvm.2019-0014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Soil-associated invertebrates which are coprophagic are capable of acting as paratenic hosts for Toxocara species larvae eggs. The aim of the present study was to assess the role of Lumbricus terrestris earthworms as potential intermediate host for Toxocara species. A total of 240 earthworms were collected from the public places in four areas of Karaj, Alborz Province, Iran. The subjects of the study were digested to detect Toxocara species using microscopy and molecular analyses. Toxocara larvae and larval eggs were recovered from 1.7% (4/240) of the sampled earthworms. The recovery rate in Shah'Abbasi and Talaghani regions in the studied areas was higher than that of the other regions. In the mentioned area, 8.3% (4/48) of earthworms were revealed to be positive for Toxocara species by microscopic observation and only one was confirmed to be positive for Toxocara canis by polymerase chain reaction (PCR). This is the first molecular report of Toxocara canis infective larvae in Lumbricus terrestris earthworms that could be demonstrated in common environment.
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Xie Y, Li H, Wang C, Li Y, Liu Y, Meng X, Wang L, Zhou X, Zheng Y, Zuo Z, Gu X, Yang G. Characterization of the complete mitochondrial genome sequence of the dog roundworm Toxascaris leonina (Nematoda, Ascarididae) from China. Mitochondrial DNA B Resour 2019; 4:3517-3519. [PMID: 33366066 PMCID: PMC7707352 DOI: 10.1080/23802359.2019.1675545] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 09/25/2019] [Indexed: 11/24/2022] Open
Abstract
Toxascaris leonina (Nematoda, Ascarididae) is a cosmopolitan nematode of canids and felids and poses potential threats to public health due to aberrant larva migrans. Herein, the complete mitochondrial genome sequence of a representative of this nematode from the dog in China was determined using next-generation sequencing technology. The assembled genome was 14,357 bp in length and encoded 36 genes, including 12 protein-coding genes, 22 transfer RNAs and 2 ribosomal RNAs. The phylogeny revealed that the canid-originated T. leonina were phylogenetic distinctiveness from the felid-originated T. leonina within the genus Toxascaris of Ascarididae, supporting that T. leonina may represent a species complex.
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Affiliation(s)
- Yue Xie
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Hongyu Li
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Chengdong Wang
- China Conservation and Research Center for Giant Panda, Wolong, Sichuan, China
| | - Yingxin Li
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yunjian Liu
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xiaduo Meng
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Lu Wang
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xuan Zhou
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Youle Zheng
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Zhicai Zuo
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xiaobin Gu
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Guangyou Yang
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
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20
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Abstract
Toxocara canis is an important zoonotic roundworm distributed worldwide. The infective larvae of T. canis are one of the causes of visceral larva migrans (VLM), a clinical syndrome in humans. Diagnosing VLM is difficult, and the differential diagnosis of the larval development stage is limited. Therefore, this experimental research aimed to diagnose T. canis larvae using a molecular method, not only in liver tissue, which is the most commonly affected tissue, but also in the limb muscles, lungs and brain tissues. For this purpose, 24 BALB/c mice were infected with 1000 embryonated T. canis eggs. Necropsies were performed on the second, fourth, seventh and 14th days post-infection. While a part of the samples were digested with pepsin-HCl, the molecular method was used for the remainder of the samples to replicate the mitochondrial DNA adenosine triphosphate (ATP) synthase subunit-6 gene region of T. canis. BbsI, a restriction endonuclease, was used to determine the specificity of the amplicons obtained from Polymerase chain reaction (PCR). The detection limit for embryonated eggs was recorded. The PCR results showed that the sensitivity of the PCR analysis was 83.3% in the liver (with 88.8% accuracy), 87.5% in the lungs (with 91.6% accuracy) and 75.0% in the brain, forelimb and hindlimb muscles (with 83.3% accuracy). In all tissues, the test specificity was determined to be 100%. In this study, the molecular method was applied to only experimentally infected BALB/c mice tissues; thus, it is suggested that it can be also employed in different paratenic hosts and materials possibly infected with T. canis.
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Detection and Identification of Toxocara Canis in Infected Dogs Using PCR. Helminthologia 2019; 56:118-123. [PMID: 31662682 PMCID: PMC6799566 DOI: 10.2478/helm-2019-0008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 12/18/2018] [Indexed: 11/25/2022] Open
Abstract
Faecal samples were collected from 224 dogs (47 villages) in Ankara. Toxocara spp. eggs were diagnosed in faeces using centrifugal flotation and sedimentation methods. A total of 21 dogs (9.38 %) were positive for Toxocara spp. eggs. In this study, we used the PCR technique that, in combination with DNA sequencing, allows the detection and identification of T.canis eggs in faeces of infected dogs. For this purpose, the ATPase subunit-6 gene (mtDNA) was selected as a target for the amplification T. canis. The primers were used to amplify 217 bp region. Amongst 21 coproscopically detected Toxocara isolates from dogs, 5 (23.8 %) samples were PCR-positive for T. canis, and the remaining 16 samples were PCR-negative. Results indicate that PCR can detect Toxocara canis DNA in faeces of infected dogs, but efficacy was low when compare to sedimentation/flotation. PCR is additional test for diagnosing of this infection. But, the difficulties of identification based on PCR in faecal examinations need to be investigated further.
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Buckle KN, Hardcastle MR, Scott I, Craig LE, French A, Gedye K, Collett MG. Toxocara canis Larval Migration Causing Verminous Pneumonia in Fading Puppies From 2 Scottish Terrier Litters. Vet Pathol 2019; 56:903-906. [PMID: 31122148 DOI: 10.1177/0300985819852131] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Migration of vertically transmitted Toxocara canis larvae through the liver and lungs is poorly documented as a cause of periparturient mortality in puppies. This case series describes 4 cases of fading puppies in 2 litters from 2 different bitches owned by the same breeder. Of the 4 cases, 4 had verminous pneumonia, 2 had fibrinoid necrosis of pulmonary arterioles, 4 had hepatic necrosis and inflammation, 2 had hepatic thrombophlebitis, and 1 had tracheal occlusion. These lesions were associated with migrating nematode larvae morphologically consistent with T. canis. The identity of the larvae was confirmed by sequencing of a portion of the ITS-2 region of nuclear ribosomal DNA. The tissues involved are consistent with the known migration pathways of this parasite. The dam of the first litter was negative for Toxocara spp. and other intestinal parasites by fecal floatation. This report highlights the need to consider T. canis migration in the differential diagnosis of fading puppies.
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Affiliation(s)
- Kelly N Buckle
- Diagnostic and Surveillance Services, Biosecurity New Zealand, Ministry for Primary Industries, Wellington, New Zealand
| | | | - Ian Scott
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Linden E Craig
- College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA
| | - Adrienne French
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Kristene Gedye
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Mark Grey Collett
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
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Abdel-Gaber R, Abdel-Ghaffar F, Al Quraishy S, Morsy K, Saleh R, Mehlhorn H. Morphological Re-Description and 18 S rDNA Sequence Confirmation of the Pinworm Aspiculuris tetraptera (Nematoda, Heteroxynematidae) Infecting the Laboratory Mice Mus musculus. J Nematol 2018; 50:117-132. [PMID: 30451433 DOI: 10.21307/jofnem-2018-026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Aspiculuris tetraptera is a heteroxynematid nematoda infecting most of the laboratory animals, occasionally mice which represent the mostly used animal for biological, medical, and pharmacological studies. The present study aimed to investigate the prevalence of nematode parasites infection in the laboratory mice Mus musculus in Egypt. Morphologically, this oxyurid possessed four distinct cephalic papillae on a cephalic plate, with three small rudimental lips carrying two sessile poorly developed labial papillae and one pair of amphidial pores. Esophagus divided into cylindrical corpus and globular bulb. Distinct cervical alae interrupted at the level of esophago-intestinal junction forming an acute angle. At the caudal end, twelve caudal papillae in male worms while an ovijector apparatus opening and a vulva surrounded by protruded lips in females were observed. The general morphological criteria include this nematode with other Aspiculuris species which were compared in the present study. Molecular characterization based on 18SSU rDNA sequencing performed to confirm the taxonomic position of this species and to documents the morphological data. Sequence alignment detects a percent of identity up to 88.0% with other Heteroxynematidae species. Phylogenetic analysis showed that the present recorded is a putative sister taxon to A. tetraptera recorded in a previous study. The SSU rDNA sequence has been deposited in the GenBank under the accession no. MG019400.
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Affiliation(s)
- Rewaida Abdel-Gaber
- Zoology Department, College of Science, King Saud University, Riyadh, Saudi Arabia ; Faculty of Science, Zoology Department, Cairo University, Cairo, Egypt
| | | | - Saleh Al Quraishy
- Zoology Department, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Kareem Morsy
- Faculty of Science, Zoology Department, Cairo University, Cairo, Egypt ; Biology Department, College of Science, King Khalid University, Abha, Saudi Arabia
| | - Rehab Saleh
- Faculty of Arts and Sciences, Biology Department, Kasr-Khiar, Al Mergheb University, Libya
| | - Heinz Mehlhorn
- Parasitology Institute, Düsseldorf University, Düsseldorf, Germany
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Oguz B, Ozdal N, Serdar Deger M. Genetic Analysis of Toxocara Spp. in Stray Cats and Dogs in Van Province, Eastern Turkey. J Vet Res 2018; 62:291-295. [PMID: 30584607 PMCID: PMC6296006 DOI: 10.2478/jvetres-2018-0042] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 08/27/2018] [Indexed: 11/20/2022] Open
Abstract
INTRODUCTION Toxocara canis and Toxocara cati are roundworms of dogs and cats. The purpose of this study was to investigate the infection caused by these ascarids in cats and dogs, using microscopic and molecular analysis methods. MATERIAL AND METHODS Adult ascarids were gathered from the faeces of dogs and cats in Van province, in 2015-2016. Existing keys and PCR sequencing of the ITS-2 fragment were used to identify the morphological features of the parasite species. RESULTS It was observed that out of 20 adult ascarids, 17 and 3 were found to be Toxocara canis and Toxocara cati, respectively. The ITS-2 gene region was amplified by PCR to perform molecular analysis. Genotyping indicated that the dogs and cats were infected with T. canis and T. cati, respectively, and none had Toxascaris leonina. CONCLUSION To the best of our knowledge, this is the first report on the molecular characteristics of adult ascaridoid nematodes from cats and dogs in Turkey. The molecular approaches established in this study enable molecular identification and genetic structure studies of the ascaridoids.
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Affiliation(s)
- Bekir Oguz
- Department of Parasitology, Faculty of Veterinary Medicine, Van Yuzuncu Yil University, 65040, Van, Turkey
| | - Nalan Ozdal
- Department of Parasitology, Faculty of Veterinary Medicine, Van Yuzuncu Yil University, 65040, Van, Turkey
| | - M. Serdar Deger
- Department of Parasitology, Faculty of Veterinary Medicine, Van Yuzuncu Yil University, 65040, Van, Turkey
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Toxocariasis: a silent threat with a progressive public health impact. Infect Dis Poverty 2018; 7:59. [PMID: 29895324 PMCID: PMC5998503 DOI: 10.1186/s40249-018-0437-0] [Citation(s) in RCA: 126] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 05/09/2018] [Indexed: 11/10/2022] Open
Abstract
Background Toxocariasis is a neglected parasitic zoonosis that afflicts millions of the pediatric and adolescent populations worldwide, especially in impoverished communities. This disease is caused by infection with the larvae of Toxocara canis and T. cati, the most ubiquitous intestinal nematode parasite in dogs and cats, respectively. In this article, recent advances in the epidemiology, clinical presentation, diagnosis and pharmacotherapies that have been used in the treatment of toxocariasis are reviewed. Main text Over the past two decades, we have come far in our understanding of the biology and epidemiology of toxocariasis. However, lack of laboratory infrastructure in some countries, lack of uniform case definitions and limited surveillance infrastructure are some of the challenges that hindered the estimation of global disease burden. Toxocariasis encompasses four clinical forms: visceral, ocular, covert and neural. Incorrect or misdiagnosis of any of these disabling conditions can result in severe health consequences and considerable medical care spending. Fortunately, multiple diagnostic modalities are available, which if effectively used together with the administration of appropriate pharmacologic therapies, can minimize any unnecessary patient morbidity. Conclusions Although progress has been made in the management of toxocariasis patients, there remains much work to be done. Implementation of new technologies and better understanding of the pathogenesis of toxocariasis can identify new diagnostic biomarkers, which may help in increasing diagnostic accuracy. Also, further clinical research breakthroughs are needed to develop better ways to effectively control and prevent this serious disease. Electronic supplementary material The online version of this article (10.1186/s40249-018-0437-0) contains supplementary material, which is available to authorized users.
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Molecular characterization of Toxocara spp. eggs isolated from public parks and playgrounds in Shiraz, Iran. J Helminthol 2018; 93:306-312. [DOI: 10.1017/s0022149x18000354] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractHuman toxocariasis, a worldwide parasitic disease, is caused by the larval stage of intestinal nematodes of dogs and cats, namely Toxocara canis and Toxocara cati. Human infection occurs by the accidental ingestion of embryonated eggs present in the soil, vegetables or on other contaminated surfaces, as well as via consumption of uncooked paratenic hosts, such as bird meat and giblets. The objective of this study was to evaluate the contamination of soil in public parks and playgrounds in Shiraz using microscopy and molecular methods. A total of 150 soil samples were collected from public parks and playgrounds in various areas of Shiraz, southern Iran. The samples were treated with saturated zinc sulphate solution, and Toxocara spp. eggs were detected by microscopic observation followed by nested polymerase chain reaction (PCR). To differentiate T. canis and T. cati eggs from each other, PCR restriction fragment length polymorphism (RFLP) of the internal transcribed spacer (ITS)-rDNA region by SalI endonuclease enzyme was used. PCR-sequencing was performed to confirm the results of the PCR-RFLP method. Based on the flotation results of the 150 soil samples, six (4%) were found to be positive for Toxocara spp. eggs, whereas nested-PCR showed 24 samples to be positive (16%). Based on the PCR-RFLP method and the sequence of the ITS-rDNA region, a total of 23 out of 24 isolates were confirmed as T. cati and one out of 24 as T. canis. The results showed a higher number of soil samples to be positive for Toxocara by the molecular method than microscopy, and higher T. cati infection in soil samples, which could have an important role in human infection with toxocariasis in this region.
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The occurrence of Toxocara species in naturally infected broiler chickens revealed by molecular approaches. J Helminthol 2016; 91:633-636. [DOI: 10.1017/s0022149x16000559] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractConsuming raw and undercooked meat is known to enhance the risk of human toxocariasis because Toxocara species have a wide range of paratenic hosts, including chickens. The aim of this study was to identify species of Toxocara in naturally infected broiler chickens using molecular approaches. A polymerase chain reaction (PCR) method was used for the differentiation of Toxocara canis and Toxocara cati larvae recovered from tissues and organs, and identified by microscopic observations. Thirty-three 35- to 47-day-old broiler chickens were used for examination of Toxocara larvae. The duodenum, liver, lungs, heart, kidneys, skeletal muscles and brain of each chicken were examined using the pepsin method, and DNA from each tissue was extracted as the template for PCR assay. The findings revealed that 5 of 33 (15.2%) broiler chickens were infected with Toxocara larvae. Larvae were recovered from the liver (n = 19), duodenum (n = 8), skeletal muscles (n = 8) and brain (n = 2) of broiler chickens naturally infected with Toxocara spp. The results showed that the frequencies of the species in the chickens were T. canis larvae (n = 5, 83.3%) and T. cati larvae (n = 1, 16.7%). Our data from the present study demonstrated the importance of broiler chickens as a paratenic host for the parasite's life cycle in the environment. The implementation of DNA amplification as a routine diagnostic technique is a specific and alternative method for identification of Toxocara larvae, and allowed the observation of specific species under field conditions within the locations where broiler chickens are typically raised and exposed to Toxocara spp. eggs or larvae.
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Peng Z, Liu S, Hou Z, Xing M. Ascarid infestation in captive Siberian tigers in China. Vet Parasitol 2016; 226:74-7. [PMID: 27514888 DOI: 10.1016/j.vetpar.2016.06.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 05/31/2016] [Accepted: 06/24/2016] [Indexed: 10/21/2022]
Abstract
The Siberian tiger is endangered and is listed by the International Union for the Conservation of Nature; the captive environment is utilized to maintain Siberian tiger numbers. Little information regarding the prevalence of parasites in Siberian tigers is available. A total of 277 fecal samples of Siberian tigers were analyzed in this study. The microscopic analysis indicated the presence of ascarid eggs of Toxascaris leonina and Toxocara cati. The ascarid infection rate was 67.5% in Siberian tigers. The internal transcribed spacer-1 (ITS-1) phylogenetic analysis indicated that T. leonina belonged to Toxascaris and that Toxo. cati belonged to Toxocara. The infestation rate and intensity of T. leonina were higher than those of Toxo. cati. One-way analysis of variance showed that the presence of T. leonina was significantly associated with age (P<0.05). Temperature changes also influenced T. leonina and Toxo. cati infestation, and a rise in temperature caused an increase in the number of T. leonina and Toxo. cati eggs. This study provides a better understanding of ascarid infestation among the captive Siberian tigers and is helpful for the prevention of the spread of infectious parasitic diseases among other tigers in the zoo.
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Affiliation(s)
- Zhiwei Peng
- College of Wildlife Resources, Northeast Forestry University, Harbin, 150040 Heilongjiang Province, China
| | - Shijie Liu
- College of Wildlife Resources, Northeast Forestry University, Harbin, 150040 Heilongjiang Province, China
| | - Zhijun Hou
- College of Wildlife Resources, Northeast Forestry University, Harbin, 150040 Heilongjiang Province, China; Key Laboratory of Wildlife Conservation, China State Forestry Administration, Harbin 150040, China.
| | - Mingwei Xing
- College of Wildlife Resources, Northeast Forestry University, Harbin, 150040 Heilongjiang Province, China.
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Gasser RB, Korhonen PK, Zhu XQ, Young ND. Harnessing the Toxocara Genome to Underpin Toxocariasis Research and New Interventions. ADVANCES IN PARASITOLOGY 2016; 91:87-110. [PMID: 27015948 DOI: 10.1016/bs.apar.2015.12.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Parasitic worms, such as flatworms (platyhelminths) and roundworms (nematodes), cause substantial morbidity and mortality in animals and people globally. The ascaridoid nematode Toxocara canis is a zoonotic parasite of socioeconomic significance worldwide. In humans, this worm causes toxocariasis (disease) mainly in underprivileged communities in both the developed and developing worlds. While reasonably well studied from clinical and epidemiological perspectives, little is understood about the molecular biology of T. canis, its relationship with its hosts and the disease that it causes. However, a recent report of the draft genome and transcriptomes of T. canis should underpin many fundamental and applied research areas in the future. The present article gives a background on Toxocara and toxocariasis, a brief account of diagnostic approaches for specific identification and genetic analysis, and gives a perspective on the impact that the genome of T. canis and advanced molecular technologies could have on our understanding of the parasite and the diseases that it causes as well as the design of new and improved approaches for the diagnosis, treatment and control of toxocariasis.
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Sequence variation in mitochondrial cox1 and nad1 genes of ascaridoid nematodes in cats and dogs from Iran. J Helminthol 2014; 89:496-501. [PMID: 24717402 DOI: 10.1017/s0022149x14000133] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The study was conducted to determine the sequence variation in two mitochondrial genes, namely cytochrome c oxidase 1 (pcox1) and NADH dehydrogenase 1 (pnad1) within and among isolates of Toxocara cati, Toxocara canis and Toxascaris leonina. Genomic DNA was extracted from 32 isolates of T. cati, 9 isolates of T. canis and 19 isolates of T. leonina collected from cats and dogs in different geographical areas of Iran. Mitochondrial genes were amplified by polymerase chain reaction (PCR) and sequenced. Sequence data were aligned using the BioEdit software and compared with published sequences in GenBank. Phylogenetic analysis was performed using Bayesian inference and maximum likelihood methods. Based on pairwise comparison, intra-species genetic diversity within Iranian isolates of T. cati, T. canis and T. leonina amounted to 0-2.3%, 0-1.3% and 0-1.0% for pcox1 and 0-2.0%, 0-1.7% and 0-2.6% for pnad1, respectively. Inter-species sequence variation among the three ascaridoid nematodes was significantly higher, being 9.5-16.6% for pcox1 and 11.9-26.7% for pnad1. Sequence and phylogenetic analysis of the pcox1 and pnad1 genes indicated that there is significant genetic diversity within and among isolates of T. cati, T. canis and T. leonina from different areas of Iran, and these genes can be used for studying genetic variation of ascaridoid nematodes.
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Liu GH, Zhou DH, Zhao L, Xiong RC, Liang JY, Zhu XQ. The complete mitochondrial genome of Toxascaris leonina: Comparison with other closely related species and phylogenetic implications. INFECTION GENETICS AND EVOLUTION 2013; 21:329-33. [PMID: 24316156 DOI: 10.1016/j.meegid.2013.11.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 11/11/2013] [Accepted: 11/26/2013] [Indexed: 01/15/2023]
Abstract
Adults of Toxascaris leonina (Nematoda: Ascarididae) live in the gastrointestinal tract of both dogs and cats, and cause significant economic losses and potential public health problem worldwide. Although many studies have given insights into this significant pathogen, to date, the complete mitochondrial (mt) genome sequence is still not available for T. leonina. Here, we sequenced the complete mt genome of T. leonina. This AT-rich (71.53%) mt genome (14,310bp) is circular and consists of 36 genes, including 12 genes for proteins, 2 genes for rRNA and 22 genes for tRNA. All mt genes of T. leonina are transcribed in the same direction. The gene order is the same as those of Ascaris spp. (Ascarididae), Toxocara spp. (Toxocaridae), Anisakis simplex and Contracaecum rudolphii B (Anisakidae), but distinct from that of Ascaridia spp. (Ascaridiidae). Phylogenetic analyses using concatenated amino acid sequences of 12 protein-coding genes by Bayesian inference (BI) showed distinct groups with high statistical support, and our data confirm that T. leonina is a member of the Ascarididae, and that this family is more closely related to the Toxocaridae rather than the Anisakidae within the Ascaridoidea. The determination of mt genome sequences of T. leonina provides novel genetic markers for studies into the systematics, population genetics and epidemiology of this parasite.
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Affiliation(s)
- Guo-Hua Liu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China; College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan Province 410128, PR China
| | - Dong-Hui Zhou
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China.
| | - Lei Zhao
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China; College of Animal Science and Technology, Jilin Agriculture University, Changchun 130118, PR China
| | - Rong-Chuan Xiong
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China
| | - Jian-Ying Liang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China; College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, PR China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China; College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan Province 410128, PR China; College of Animal Science and Technology, Jilin Agriculture University, Changchun 130118, PR China.
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The epidemiology and public health importance of toxocariasis: A zoonosis of global importance. Int J Parasitol 2013; 43:999-1008. [DOI: 10.1016/j.ijpara.2013.07.004] [Citation(s) in RCA: 264] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 07/16/2013] [Accepted: 07/18/2013] [Indexed: 11/21/2022]
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A comparative histopathology, serology and molecular study, on experimental ocular toxocariasis by Toxocara cati in Mongolian gerbils and Wistar rats. BIOMED RESEARCH INTERNATIONAL 2013; 2013:109580. [PMID: 24069585 PMCID: PMC3773411 DOI: 10.1155/2013/109580] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Revised: 07/22/2013] [Accepted: 07/29/2013] [Indexed: 11/17/2022]
Abstract
The aim of this study was to compare the performance of three in-house diagnostic tests, that is, histopathology, enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR), for the diagnosis after experimental infection with Toxocara cati. Twenty Mongolian gerbils and Wistar rats were divided into ten groups (n = 2/group). Toxocara cati infections were established in Mongolian gerbils and Wistar rats by administering doses of 240 and 2500 embryonated Toxocara cati eggs by gavage, respectively. Tissue sections were stained with Haematoxylin and Eosin and observed under the light microscope. Sera and vitreous fluid collected from separate infected groups were tested against Toxocara cati antigens, for 92 days postinfection. Genomic DNA was extracted from formalin-fixed paraffin-embedded (FFPE) blocks, and aqueous fluids belong to the animals. The histopathology test gave negative results among the groups of animals examined between 5 and 92 days postinfection. The ELISA results showed that anti-Toxocara antibodies have risen between 7 and 61 days postinfection in sera and vitreous fluid in the animals infected, respectively. Analysis of PCR products revealed positive band (660 bp) in the orbital tissue infected Mongolian gerbils at 5 days postinfection. Of the three evaluated methods, the PCR could be recommended for scientific and laboratory diagnoses of toxocariasis in experimentally infected animals.
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Khademvatan S, Rahim F, Tavalla M, Abdizadeh R, Hashemitabar M. PCR-based molecular characterization of Toxocara spp. using feces of stray cats: a study from Southwest Iran. PLoS One 2013; 8:e65293. [PMID: 23755213 PMCID: PMC3670902 DOI: 10.1371/journal.pone.0065293] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2012] [Accepted: 04/22/2013] [Indexed: 11/18/2022] Open
Abstract
Feces of stray cat are potential sources of gastrointestinal parasites and play a crucial role in spreading and transmitting parasite eggs, larvae, and oocysts through contamination of soil, food, or water. In this study, we investigated the prevalence of Toxocara spp. infection in stray cats in Ahvaz city, southwest Iran. Eggs of Toxocara spp. in feces of stray cats were detected by the sucrose flotation method, and identification was conducted by polymerase chain reaction (PCR) and DNA sequencing. Of the 140 fecal samples that were randomly collected from public environments during the months of January to May 2012, 45% were found to harbour Toxocara spp. eggs. The highest prevalence of Toxocara spp. eggs was found in the central area of Ahvaz city (28.6%). T. canis eggs were found in 4 (6.34%) of the 63 positive samples. Stray cats are found in parks, playgrounds, and other public places and may be a potential contamination risk. Identification of Toxocara spp. using molecular methods is sufficiently sensitive to detect low levels of parasites and identify the different Toxocara spp. in feces. The relatively high prevalence of Toxocara spp. infection may continue to increase due to lack of effective environmental hygiene control in Iran. Consequently, there is a need to plan adequate programs to detect, identify, and control this infection as well as stray cats in the region.
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Affiliation(s)
- Shahram Khademvatan
- Cellular and Molecular Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
- Department of Medical Parasitology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
- * E-mail: (SK); (FR)
| | - Fakher Rahim
- Toxicology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
- * E-mail: (SK); (FR)
| | - Mahdi Tavalla
- Department of Medical Parasitology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Rahman Abdizadeh
- Department of Medical Parasitology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mahmoud Hashemitabar
- Cellular and Molecular Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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A perfect time to harness advanced molecular technologies to explore the fundamental biology of Toxocara species. Vet Parasitol 2013; 193:353-64. [DOI: 10.1016/j.vetpar.2012.12.031] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Comparison of six simple methods for extracting ribosomal and mitochondrial DNA from Toxocara and Toxascaris nematodes. Exp Parasitol 2013; 134:155-9. [PMID: 23499880 DOI: 10.1016/j.exppara.2013.02.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 02/08/2013] [Accepted: 02/19/2013] [Indexed: 11/21/2022]
Abstract
Six simple methods for extraction of ribosomal and mitochondrial DNA from Toxocara canis, Toxocara cati and Toxascaris leonina were compared by evaluating the presence, appearance and intensity of PCR products visualized on agarose gels and amplified from DNA extracted by each of the methods. For each species, two isolates were obtained from the intestines of their respective hosts: T. canis and T. leonina from dogs, and T. cati from cats. For all isolates, total DNA was extracted using six different methods, including grinding, boiling, crushing, beating, freeze-thawing and the use of a commercial kit. To evaluate the efficacy of each method, the internal transcribed spacer (ITS) region and the cytochrome c oxidase subunit 1 (cox1) gene were chosen as representative markers for ribosomal and mitochondrial DNA, respectively. Among the six DNA extraction methods, the beating method was the most cost effective for all three species, followed by the commercial kit. Both methods produced high intensity bands on agarose gels and were characterized by no or minimal smear formation, depending on gene target; however, beating was less expensive. We therefore recommend the beating method for studies where costs need to be kept at low levels.
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Durant JF, Irenge LM, Fogt-Wyrwas R, Dumont C, Doucet JP, Mignon B, Losson B, Gala JL. Duplex quantitative real-time PCR assay for the detection and discrimination of the eggs of Toxocara canis and Toxocara cati (Nematoda, Ascaridoidea) in soil and fecal samples. Parasit Vectors 2012; 5:288. [PMID: 23216873 PMCID: PMC3533947 DOI: 10.1186/1756-3305-5-288] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 11/23/2012] [Indexed: 11/19/2022] Open
Abstract
Background Toxocarosis is a zoonotic disease caused by Toxocara canis (T. canis) and/or Toxocara cati (T. cati), two worldwide distributed roundworms which are parasites of canids and felids, respectively. Infections of humans occur through ingestion of embryonated eggs of T. canis or T. cati, when playing with soils contaminated with dogs or cats feces. Accordingly, the assessment of potential contamination of these areas with these roundworms eggs is paramount. Methods A duplex quantitative real-time PCR (2qPCR) targeting the ribosomal RNA gene internal transcribed spacer (ITS2) has been developed and used for rapid and specific identification of T. canis and T. cati eggs in fecal and soil samples. The assay was set up on DNA samples extracted from 53 adult worms including T. canis, T. cati, T. leonina, Ascaris suum (A. suum) and Parascaris equorum (P. equorum). The assay was used to assess the presence of T. cati eggs in several samples, including 12 clean soil samples spiked with eggs of either T. cati or A. suum, 10 actual soil samples randomly collected from playgrounds in Brussels, and fecal samples from cats, dogs, and other animals. 2qPCR results on dogs and cats fecal samples were compared with results from microscopic examination. Results 2qPCR assay allowed specific detection of T. canis and T. cati, whether adult worms, eggs spiked in soil or fecal samples. The 2qPCR limit of detection (LOD) in spiked soil samples was 2 eggs per g of soil for a turnaround time of 3 hours. A perfect concordance was observed between 2qPCR assay and microscopic examination on dogs and cats feces. Conclusion The newly developed 2qPCR assay can be useful for high throughput prospective or retrospective detection of T.canis and/or T. cati eggs in fecal samples as well as in soil samples from playgrounds, parks and sandpits.
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Affiliation(s)
- Jean-Francois Durant
- Centre de Technologies Moléculaires Appliquées, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Clos Chapelle-aux-Champs, 30 B1.30.24, 1200 Brussels, Belgium
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Intraspecific variation between the ITS sequences of Toxocara canis, Toxocara cati and Toxascaris leonina from different host species in south-western Poland. J Helminthol 2012; 87:432-42. [PMID: 23069601 DOI: 10.1017/s0022149x1200048x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Some parasitic nematodes can inhabit different definitive hosts, which raises the question of the intraspecific variability of the nematode genotype affecting their preferences to choose particular species as hosts. Additionally, the issue of a possible intraspecific DNA microheterogeneity in specimens from different parts of the world seems to be interesting, especially from the evolutionary point of view. The problem was analysed in three related species - Toxocara canis, Toxocara cati and Toxascaris leonina - specimens originating from Central Europe (Poland). Using specific primers for species identification, internal transcribed spacer (ITS)-1 and ITS-2 regions were amplified and then sequenced. The sequences obtained were compared with sequences previously described for specimens originating from other geographical locations. No differences in nucleotide sequences were established in T. canis isolated from two different hosts (dogs and foxes). A comparison of ITS sequences of T. canis from Poland with sequences deposited in GenBank showed that the scope of intraspecific variability of the species did not exceed 0.4%, while in T. cati the differences did not exceed 2%. Significant differences were found in T. leonina, where ITS-1 differed by 3% and ITS-2 by as much as 7.4% in specimens collected from foxes in Poland and dogs in Australia. Such scope of differences in the nucleotide sequence seems to exceed the intraspecific variation of the species.
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Chen J, Zhou DH, Nisbet AJ, Xu MJ, Huang SY, Li MW, Wang CR, Zhu XQ. Advances in molecular identification, taxonomy, genetic variation and diagnosis of Toxocara spp. INFECTION GENETICS AND EVOLUTION 2012; 12:1344-8. [DOI: 10.1016/j.meegid.2012.04.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2012] [Revised: 04/20/2012] [Accepted: 04/21/2012] [Indexed: 12/28/2022]
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Update on eosinophilic meningoencephalitis and its clinical relevance. Clin Microbiol Rev 2009; 22:322-48, Table of Contents. [PMID: 19366917 DOI: 10.1128/cmr.00044-08] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Eosinophilic meningoencephalitis is caused by a variety of helminthic infections. These worm-specific infections are named after the causative worm genera, the most common being angiostrongyliasis, gnathostomiasis, toxocariasis, cysticercosis, schistosomiasis, baylisascariasis, and paragonimiasis. Worm parasites enter an organism through ingestion of contaminated water or an intermediate host and can eventually affect the central nervous system (CNS). These infections are potentially serious events leading to sequelae or death, and diagnosis depends on currently limited molecular methods. Identification of parasites in fluids and tissues is rarely possible, while images and clinical examinations do not lead to a definitive diagnosis. Treatment usually requires the concomitant administration of corticoids and anthelminthic drugs, yet new compounds and their extensive and detailed clinical evaluation are much needed. Eosinophilia in fluids may be detected in other infectious and noninfectious conditions, such as neoplastic disease, drug use, and prosthesis reactions. Thus, distinctive identification of eosinophils in fluids is a necessary component in the etiologic diagnosis of CNS infections.
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Smith H, Holland C, Taylor M, Magnaval JF, Schantz P, Maizels R. How common is human toxocariasis? Towards standardizing our knowledge. Trends Parasitol 2009; 25:182-8. [PMID: 19269251 DOI: 10.1016/j.pt.2009.01.006] [Citation(s) in RCA: 201] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 01/23/2009] [Accepted: 01/23/2009] [Indexed: 11/18/2022]
Abstract
Our understanding of the global impact and cost of human toxocariasis is poor because there is insufficient clinical awareness and no clear repository for the efficacy of clinical, laboratory and treatment interventions. Uniform clinical and laboratory investigative approaches maximize disease diagnosis. International collaboration is required to develop web-based, professional educational support, surveillance questionnaires and standardized serodiagnostic criteria. Determining clinical benefits and treatment outcomes using less crossreactive antigens will enhance clinical and treatment interventions. Increased liaison will identify realistic occurrence and prevalence data and cost benefits of intervention. Web-based centres of excellence and repositories of current knowledge, which augment current veterinary and public health educational sites, should be supported. Expected outcomes should be capable of addressing the clinical and financial burdens of this treatable disease.
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Affiliation(s)
- Huw Smith
- Scottish Parasite Diagnostic Laboratory, Stobhill Hospital, Glasgow G21 3UW, UK.
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Li MW, Lin RQ, Song HQ, Sani RA, Wu XY, Zhu XQ. Electrophoretic analysis of sequence variability in three mitochondrial DNA regions for ascaridoid parasites of human and animal health significance. Electrophoresis 2008; 29:2912-7. [PMID: 18546167 DOI: 10.1002/elps.200700752] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Sequence variability in three mitochondrial DNA (mtDNA) regions, namely cytochrome c oxidase subunit 1 (cox1), NADH dehydrogenase subunits 1 and 4 (nad1 and nad4), among and within Toxocara canis, T. cati, T. malaysiensis, T. vitulorum and Toxascaris leonina from different geographical origins was examined by a mutation-scanning approach. A portion of the cox1 gene (pcox1), a portion of the nad1 and nad4 genes (pnad1 and pnad4) were amplified separately from individual ascaridoid nematodes by polymerase chain reaction and the amplicons analyzed by single-strand conformation polymorphism (SSCP). Representative samples displaying sequence variation in SSCP profiles were subjected to sequencing in order to define genetic markers for their specific identification and differentiation. While the intra-specific sequence variations within each of the five ascaridoid species were 0.2-3.7% for pcox1, 0-2.8% for pnad1 and 0-2.3% for pnad4, the inter-specific sequence differences were significantly higher, being 7.9-12.9% for pcox1, 10.7-21.1% for pnad1 and 12.9-21.7% for pnad4, respectively. Phylogenetic analyses based on the combined sequences of pcox1, pnad1 and pnad4 revealed that the recently described species T. malaysiensis was more closely related to T. cati than to T. canis. These findings provided mtDNA evidence for the validity of T. malaysiensis and also demonstrated clearly the usefulness and attributes of the mutation-scanning sequencing approach for studying the population genetic structures of these and other nematodes of socio-economic importance.
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Affiliation(s)
- Ming-Wei Li
- Laboratory of Parasitology, College of Veterinary Medicine, South China Agricultural University, Guangdong Province, The People's Republic of China
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Chen Q, Yu HQ, Lun ZR, Chen XG, Song HQ, Lin RQ, Zhu XQ. Specific PCR assays for the identification of common anisakid nematodes with zoonotic potential. Parasitol Res 2008; 104:79-84. [PMID: 18758823 DOI: 10.1007/s00436-008-1161-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2008] [Accepted: 08/12/2008] [Indexed: 11/29/2022]
Abstract
Based on the sequences of the internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA (rDNA) for six taxa of anisakids, namely, Anisakis simplex (s.s.), Anisakis typica, Anisakis pegreffii, Hysterothylacium aduncum, Hysterothylacium sp, and Contracaccum osculatum C, specific primers were designed in the ITS-1 and/or ITS-2 for each of the six anisakid taxa. These specific primers were used to develop polymerase chain reaction (PCR) tools for the identification of these anisakid taxa of sea fish by amplifying partial ITS-1 and/or ITS-2 of rDNA from anisakid nematodes. This approach allowed their specific identification, with no amplicons being amplified from heterogeneous DNA samples, and sequencing confirmed the identity of the DNA fragments amplified. The minimum amounts of DNA detectable using the PCR assays were 0.5-1 ng. These PCR tools were then applied to ascertain the specific identity of 143 anisakid larval samples collected from fish in China, Canada, Thailand, and Indonesia, and these anisakid samples were identified to represent one of the six anisakid taxa. These PCR assays based on ITS sequences should provide useful molecular tools for the accurate identification and molecular epidemiological investigations of anisakid infections in humans and fish.
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Affiliation(s)
- Q Chen
- South China Agricultural University, Guangzhou, Guangdong Province, 510642, People's Republic of China
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Li MW, Lin RQ, Song HQ, Wu XY, Zhu XQ. The complete mitochondrial genomes for three Toxocara species of human and animal health significance. BMC Genomics 2008; 9:224. [PMID: 18482460 PMCID: PMC2396643 DOI: 10.1186/1471-2164-9-224] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2007] [Accepted: 05/16/2008] [Indexed: 11/10/2022] Open
Abstract
Background Studying mitochondrial (mt) genomics has important implications for various fundamental areas, including mt biochemistry, physiology and molecular biology. In addition, mt genome sequences have provided useful markers for investigating population genetic structures, systematics and phylogenetics of organisms. Toxocara canis, Toxocara cati and Toxocara malaysiensis cause significant health problems in animals and humans. Although they are of importance in human and animal health, no information on the mt genomes for any of Toxocara species is available. Results The sizes of the entire mt genome are 14,322 bp for T. canis, 14029 bp for T. cati and 14266 bp for T. malaysiensis, respectively. These circular genomes are amongst the largest reported to date for all secernentean nematodes. Their relatively large sizes relate mainly to an increased length in the AT-rich region. The mt genomes of the three Toxocara species all encode 12 proteins, two ribosomal RNAs and 22 transfer RNA genes, but lack the ATP synthetase subunit 8 gene, which is consistent with all other species of Nematode studied to date, with the exception of Trichinella spiralis. All genes are transcribed in the same direction and have a nucleotide composition high in A and T, but low in G and C. The contents of A+T of the complete genomes are 68.57% for T. canis, 69.95% for T. cati and 68.86% for T. malaysiensis, among which the A+T for T. canis is the lowest among all nematodes studied to date. The AT bias had a significant effect on both the codon usage pattern and amino acid composition of proteins. The mt genome structures for three Toxocara species, including genes and non-coding regions, are in the same order as for Ascaris suum and Anisakis simplex, but differ from Ancylostoma duodenale, Necator americanus and Caenorhabditis elegans only in the location of the AT-rich region, whereas there are substantial differences when compared with Onchocerca volvulus,Dirofiliria immitis and Strongyloides stercoralis. Phylogenetic analyses based on concatenated amino acid sequences of 12 protein-coding genes revealed that the newly described species T. malaysiensis was more closely related to T. cati than to T. canis, consistent with results of a previous study using sequences of nuclear internal transcribed spacers as genetic markers. Conclusion The present study determined the complete mt genome sequences for three roundworms of human and animal health significance, which provides mtDNA evidence for the validity of T. malaysiensis and also provides a foundation for studying the systematics, population genetics and ecology of these and other nematodes of socio-economic importance.
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Affiliation(s)
- Ming-Wei Li
- Laboratory of Parasitology, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, ProC.
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Parel JDC, Galula JU, Ooi HK. Characterization of rDNA sequences from Syphacia obvelata, Syphacia muris, and Aspiculuris tetraptera and development of a PCR-based method for identification. Vet Parasitol 2008; 153:379-83. [PMID: 18374491 DOI: 10.1016/j.vetpar.2008.02.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2007] [Revised: 01/28/2008] [Accepted: 02/01/2008] [Indexed: 11/19/2022]
Abstract
To differentiate the morphologically similar pinworms of the common laboratory rodents, such as Syphacia obvelata and Syphacia muris, we amplified and sequenced the region spanning the internal transcribed spacer 1 (ITS-1), 5.8S gene, and ITS-2 of the ribosomal DNA followed by designing of species-specific primers for future use in the identification of the worms. It was observed that S. obvelata, S. muris and Aspiculuris tetraptera can be differentiated from each other based on their rDNA sequences. This is the first report of the ITS-1, 5.8S, and ITS-2 of the rDNA of the three aforementioned rodent pinworm species. The use of restriction endonucleases, AluI or RsaI, further allowed the delineation of the three species. Moreover, we also constructed species-specific primers that were designed for unique regions of the ITS-2 of the three species. This approach allowed their specific identification with no amplicons being amplified from heterogenous DNA samples, and sequencing confirmed the identity of the sequences amplified. Thus, the use of these specific primers along with PCR-RFLP can serve as useful tools for the identification of pinworms in rats, mice, and wild rodents.
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Affiliation(s)
- Joan Dee C Parel
- Department of Veterinary Medicine, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan
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