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Abd El Wahab WM, Ali MI, Ibrahim SS, Mohamed YA, Hamdy DA. Toxocariasis: potential association with bronchial asthma, and pneumonia among pediatric children. J Parasit Dis 2023; 47:93-100. [PMID: 36910311 PMCID: PMC9998777 DOI: 10.1007/s12639-022-01543-w] [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: 05/30/2022] [Accepted: 10/20/2022] [Indexed: 11/25/2022] Open
Abstract
Toxocariasis is an underestimated geohelminthic infection which shows respiratory changes concurrent with larval migration. The purpose of the present study was to detect Toxocara seropositivity in asthmatic and pneumonic children, and in turn to evaluate its association with the children clinical manifestations, laboratory test results, and sociodemographic risk factors. A total of 50 asthmatic, 50 pneumonic children and 50 healthy controls were subjected to stool analysis by direct wet mount and concentration techniques to exclude possible cross reactivity. Blood samples were collected for complete blood count and assessment of eosinophil count. Sera were examined for anti-Toxocara IgG antibodies, and measurement of total IgE level. Anti Toxocara IgG was detected in 27.3% (41/150) of the studied children. It was significantly higher in asthmatic group compared to controls (26%. p value = 0.033) and significantly highest in pneumonia group compared to both bronchial asthma group (46%. p value = 0.030) and control group (10%. p value = 0.001). There was a significant association between anti Toxocara IgG seroprevalence and each of eosinophilia, total IgE and both combined. Anti Toxocara IgG showed significant higher percentage in asthmatic children who recorded history of soil contact and pets contact as compared to control and pneumonic groups. Toxocara IgG seropositivity was highly associated with fever, cough, wheezes and dyspnea with statistical significance. Toxocara seropositivity has to be considered as a vital associated factor for asthmatic and pneumonic children, and eventually better to be considered in differential diagnosis by pediatricians. Further studies are still needed to explore the correlation between toxocariasis and different patient categories.
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Affiliation(s)
- Wegdan M. Abd El Wahab
- Department of Medical Parasitology, College of Medicine, Beni-Suef University, Beni-Suef, Egypt
| | - Mona I. Ali
- Department of Medical Parasitology, College of Medicine, Beni-Suef University, Beni-Suef, Egypt
| | - Shimaa S. Ibrahim
- Department of Medical Parasitology, College of Medicine, Beni-Suef University, Beni-Suef, Egypt
| | - Yasmen A. Mohamed
- Department of Pediatrics, College of Medicine, Beni-Suef University, Beni-Suef, Egypt
| | - Doaa A. Hamdy
- Department of Medical Parasitology, College of Medicine, Beni-Suef University, Beni-Suef, Egypt
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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: 1.5] [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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Mesa-Arango JA, Olave-Velandia AM, García-Montoya GM, Isaza-Agudelo JP, Jiménez-Ruiz A, Alzate JF. Evaluation of new Toxocara canis chimeric antigens as an alternative to conventional TES-Ag for anti- Toxocara antibodies detection. Heliyon 2022; 8:e11144. [PMID: 36299519 PMCID: PMC9589186 DOI: 10.1016/j.heliyon.2022.e11144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 07/01/2022] [Accepted: 10/13/2022] [Indexed: 11/06/2022] Open
Abstract
Human toxocariasis is one of the neglected helminthiases and it is caused by the zoonotic roundworm species Toxocara canis and Toxocara cati. Diagnosis of human toxocariasis is based on the combination of clinical, parasitological, and epidemiological criteria, as well as serology tests that detect anti-Toxocara antibodies. Notwithstanding, due to the absence of pathognomonic symptoms and signs of the disease, serology is the key evidence to support a conclusive diagnosis. TES-ELISA is the most widely used serological test for diagnosis. However, cross-reaction of TES antigens with antibodies produced to other helminth antigens is a major drawback for its application in countries with high parasitic prevalence. T. canis recombinant antigens have been described as an alternative to native TES for diagnosis. Nevertheless, the selection of antigenic proteins is a complex process that requires validation. In this paper, we developed an eGFP carrier-based system to express and purify blocks of recombinant polypeptides of T. canis antigenic proteins. Intense cross-reaction polypeptides were detected by Immunoblot and avoided to finally produce a chimeric prototype protein. Additionally, a control chimeric protein that harbors the complete tested proteins was produced. Purified chimeric antigens were tested in ELISA and Immunoblot assays with 310 sera samples of negative and positive control individuals. Our results showed that chimeric rCHITC0 and rCHITC1 antigens (with sensitivities of 62% 58%, 38% and 16% in IB-rCHITC0, ELISA-rCHITC0, ELISA-rCHITC1 and IB-rCHITC1 respectively for OLMS) can perform better in terms of specificity (being 91%, 89%, 87% and 76% for ELISA-rCHITC1, IB-rCHITC1, ELISA-rCHITC0 and IB-rCHITC0 respectively for OLMS) than T. canis TES-ELISA (with 61% specificity), giving a higher signal with serum samples of infected individuals as well the possibility to discriminate false positive cases with other parasitic infections. Our data suggest that T. canis chimeric proteins, represent candidate antigens for phase II studies.
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Affiliation(s)
- Jairo A. Mesa-Arango
- Centro Nacional de Secuenciación Genómica-CNSG, Sede de Investigación Universitaria-SIU, Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad de Antioquia, Colombia,Grupo de Parasitología, Facultad de Medicina, Universidad de Antioquia, Colombia
| | - Ana M. Olave-Velandia
- Centro Nacional de Secuenciación Genómica-CNSG, Sede de Investigación Universitaria-SIU, Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad de Antioquia, Colombia
| | - Gisela M. García-Montoya
- Centro Nacional de Secuenciación Genómica-CNSG, Sede de Investigación Universitaria-SIU, Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad de Antioquia, Colombia,Grupo de Parasitología, Facultad de Medicina, Universidad de Antioquia, Colombia
| | - Juan P. Isaza-Agudelo
- Centro Nacional de Secuenciación Genómica-CNSG, Sede de Investigación Universitaria-SIU, Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad de Antioquia, Colombia,Grupo de Parasitología, Facultad de Medicina, Universidad de Antioquia, Colombia
| | - Antonio Jiménez-Ruiz
- Departamento de Biología de Sistemas, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain
| | - Juan F. Alzate
- Centro Nacional de Secuenciación Genómica-CNSG, Sede de Investigación Universitaria-SIU, Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad de Antioquia, Colombia,Grupo de Parasitología, Facultad de Medicina, Universidad de Antioquia, Colombia,Corresponding author.
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Naderbandi M, Zibaei M, Haniloo A, Firoozeh F, Hatami Z, Shokri E, Taira K. Larva migrans in BALB/c mice experimentally infected with Toxocara cati ensured by PCR assay. BMC Vet Res 2022; 18:257. [PMID: 35791007 PMCID: PMC9254581 DOI: 10.1186/s12917-022-03366-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 06/30/2022] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Toxocara cati, the cat roundworm, is a parasitic nematode that known to cause toxocariasis in intermediate hosts and humans. In this study, we characterized the dynamics of T. cati larvae migration in BALB/c mice after inoculation with eggs and ensured the migration detecting the larval DNA by a PCR. To evaluate the dynamics of larval migration and distribution, twenty-four BALB/c mice were orally inoculated with 2500 T. cati infective eggs and the visceral organs of the infected animals were examined by pepsin digestion and microscopic parasite counts, followed by PCR at day 1 to 28 post-inoculation. RESULTS The PCR assays were successfully used for detection of T. cati larvae in tissue samples and T. cati larvae and the DNAs were found in the liver, lungs, heart, kidneys and the brain. We detected T. cati in 92.2% of tissue samples by PCR, 30% higher than the conventional pepsin digestion technique. CONCLUSION Our findings demonstrated that the PCR assay is a sensitive and specific for the detection of T. cati larvae. Therefore, it could become a useful tool for the investigation of the dynamics of larval migration and Toxocara infection in murine model.
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Affiliation(s)
- Majid Naderbandi
- Department of Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Mohammad Zibaei
- Department of Parasitology and Mycology, School of Medicine, Alborz University of Medical Sciences, P.O. Box: 3149779453, Karaj, Iran
| | - Ali Haniloo
- Department of Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Farzaneh Firoozeh
- Department of Microbiology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
| | - Zahra Hatami
- Department of Parasitology and Mycology, School of Medicine, Alborz University of Medical Sciences, P.O. Box: 3149779453, Karaj, Iran
| | - Elham Shokri
- Department of Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Kensuke Taira
- Laboratory of Parasitology, School of Veterinary Medicine, Azabu University, Fuchinobe, Sagamihara, Kanagawa Japan
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Shehata O, Aboelhadid SM, Arafa WM, Moawad UK, Hussien KH, Ali MI, El-Ashram S, Gawad SSA, Abdel-Aziz SAA. Assessment of the efficacy of thymol against Toxocara vitulorum in experimentally infected rats. J Parasit Dis 2022; 46:454-465. [DOI: 10.1007/s12639-022-01465-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 01/09/2022] [Indexed: 10/19/2022] Open
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Raissi V, Mohebali M, Kia EB, Rahimi Foroushani A, Sohrabi N, Rokni MB, Zibaei M. Expression of Mir-21 and Mir-103a in Toxocara canis: Potential for Diagnosis of Human Toxocariasis. IRANIAN JOURNAL OF PARASITOLOGY 2020; 15:559-567. [PMID: 33884013 PMCID: PMC8039491 DOI: 10.18502/ijpa.v15i4.4865] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Background: Toxocariasis is one of the most neglected zoonotic diseases, predominantly caused by Toxocara canis. We aimed to evaluate the expression of microRNAs 21 and 103a in seropositive individuals for human toxocariasis as diagnostic biomarkers. Methods: This study was conducted on 324 individuals for ELISA test on toxocariasis in Tehran and Karaj, Iran 2019. Then positive samples for anti-Toxocara IgG were obtained to quantitative Real-time PCR (qRT-PCR) assays to investigate the transcriptional profiles of miRNAs predicted to be involved in developmental and reproductive processes. qPCR was employed to assess levels of transcription for miRNAs of 103a and 21 in plasma samples. Results: After the experiments, the results were evaluated by REST software, Livak formula and quantitative t-test. The analyzes performed on human samples showed that in the case group compared to the control group, only in Tc-miR-21 gene, a 0.3-fold increase in expression was obtained with REST software (Fold change ≤ 1.5, P>0.05), which was statistically significant by t-test (P<0.05). Conclusion: To our knowledge, this is the first study to evaluate miR-21 and miR-103a in toxocariasis, which shed light on the fundamental role of it as a biomarker and diagnostic tool. However, due to the changes in expression of these miRNAs were not vast to be used as biomarkers in diagnosis. Despite of that the changes in the expression of these miRNAs were not vast but they could serve as novel promising biomarkers for diagnosis of toxocariasis.
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Affiliation(s)
- Vahid Raissi
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Mohebali
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Eshrat Bigom Kia
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Abbas Rahimi Foroushani
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Nasrin Sohrabi
- Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Bagher Rokni
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Zibaei
- Department of Parasitology and Mycology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran.,Evidence-Based Phytotherapy and Complementary Medicine Research Center, Alborz University of Medical Sciences, Karaj, Iran
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Song HB, Lee D, Jin Y, Kang J, Cho SH, Park MS, Park JH, Song WJ, Kang HR, Lee SH, Hong ST, Choi MH. Prevalence of Toxocariasis and Its Risk Factors in Patients with Eosinophilia in Korea. THE KOREAN JOURNAL OF PARASITOLOGY 2020; 58:413-419. [PMID: 32871635 PMCID: PMC7462808 DOI: 10.3347/kjp.2020.58.4.413] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 07/28/2020] [Indexed: 11/23/2022]
Abstract
Eosinophilia occurs commonly in many diseases including allergic diseases and helminthic infections. Toxocariasis has been suggested as one cause of eosinophilia. The present study was undertaken to examine the prevalence of toxocariasis in patients with eosinophilia and to identify the risk factors for toxocariasis. This prospective cohort study recruited a total of 81 patients with eosinophilia (34 males and 47 females) who visited the outpatient clinic at Seoul National University Hospital from January 2017 to February 2018 and agreed to participate in this study. The prevalence of toxocariasis was examined by T. canis-specific ELISA, and the various risk factors for toxocariasis were evaluated by a questionnaire survey. Among 81 patients with eosinophilia, 18 were positive for anti-T. canis antibodies (22.2%); 88.9% were male (16/18) and 11.1% were female (2/18). Multivariate statistical analysis revealed that males (OR 21.876, 95% CI: 1.667–287.144) with a history of consuming the raw meat or livers of animals (OR 5.899, 95% CI: 1.004–34.669) and a heavy alcohol-drinking habit (OR 8.767, 95% CI: 1.018–75.497) were at higher risk of toxocariasis in patients with eosinophilia. Toxocariasis should be considered a potential cause of eosinophilia when the patient has a history of eating the raw meat or livers of animals in Korea. A single course of albendazole is recommended to reduce the migration of Toxocara larvae in serologically positive cases with eosinophilia.
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Affiliation(s)
- Hyun Beom Song
- Department of Tropical Medicine and Parasitology and Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Deokho Lee
- Department of Tropical Medicine and Parasitology and Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Yan Jin
- Department of Microbiology, Dongguk University College of Medicine, Gyeongju 38066, Korea
| | - Jinwoo Kang
- Department of Internal Medicine and Liver Research Institute, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Shin-Hyeong Cho
- Division of Vectors and Parasitic Diseases, Centers for Disease Control and Prevention, Osong 28159, Korea
| | - Min Sun Park
- Department of Family Medicine, Seoul National University Hospital, Seoul 03080, Korea
| | - Jin-Ho Park
- Department of Family Medicine, Seoul National University Hospital, Seoul 03080, Korea.,Department of Family Medicine, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Woo-Jung Song
- Division of Allergy and Clinical Immunology, Department of Internal Medicine and Institute of Allergy and Clinical Immunology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Hye-Ryun Kang
- Division of Allergy and Clinical Immunology, Department of Internal Medicine and Institute of Allergy and Clinical Immunology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Sang Hyub Lee
- Department of Internal Medicine and Liver Research Institute, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Sung-Tae Hong
- Department of Tropical Medicine and Parasitology and Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Min-Ho Choi
- Department of Tropical Medicine and Parasitology and Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul 03080, Korea
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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: 1.8] [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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Rostami A, Sepidarkish M, Ma G, Wang T, Ebrahimi M, Fakhri Y, Mirjalali H, Hofmann A, Macpherson CNL, Hotez PJ, Gasser RB. Global prevalence of Toxocara infection in cats. ADVANCES IN PARASITOLOGY 2020; 109:615-639. [PMID: 32381220 DOI: 10.1016/bs.apar.2020.01.025] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Zoonotic parasites, including Toxocara species, of pet and stray cats are of public health importance. Justification for, and the design and implementation of prevention and control of human toxocariasis may benefit from an understanding of the zoonotic potential and prevalence of parasites in this definitive host species. This is the first systematic review and meta-analysis of cross-sectional studies, conducted to estimate the prevalence of Toxocara infection(s) in cats by geographical location, type (rural vs urban and stray vs pet), gender and age. Pooled data were assessed using a random effects-model as well as several meta-regression and stratified analyses conducted. Of 1733 peer-reviewed articles, 143 were included in this review and represented 2,158,069 cats from 51 countries. The global pooled (95% CI) prevalence of Toxocara infection in cats was 17.0% (16.1-17.8%), being highest in African (43.3%, 28.3-58.4%) and lowest in South American (12.6%, 8.2-17.0%) countries. In other WHO regions, prevalence rates of Toxocara were as follows: Eastern Mediterranean (21.6%, 15.1-28.1%), North America (18.3%, 15.4-21.2%), Europe (17.8%, 15.9-19.7%), Western Pacific (17.3%, 14.7-19.9%), and South-East Asia (14.9%, 9.8-20.1%). Prevalence of Toxocara was higher in low-income tropical countries and also in stray (28.6%, 25.1-32.1%) and young (≤12 months of age) (27.7%, 23.4-32.0%) cats than in pet (11.6%, 10.7-12.5%) and older cats (>12 months of age) (23.8%, 14.8-32.7%). This review indicates that ~118-150 million cats worldwide serve as definitive hosts of Toxocara, shedding eggs and thus contributing to the public health risk of human infection. Prevention and control of this zoonosis in cats should receive greater attention by health officials and cat owners, particularly in countries where risk factors and prevalence are highest.
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Affiliation(s)
- Ali Rostami
- Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.
| | - Mahdi Sepidarkish
- Department of Epidemiology and Biostatistics, School of Medicine, Babol University of Medical Sciences, Babol, Iran
| | - Guangxu Ma
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Tao Wang
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Maryam Ebrahimi
- Department of Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Yadolah Fakhri
- Department of Environmental Health Engineering, Student Research Committee, School of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamed Mirjalali
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Andreas Hofmann
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Calum N L Macpherson
- School of Graduate Studies, School of Veterinary Medicine, St. George's University, WINDREF, Grenada, West Indies
| | - Peter J Hotez
- Texas Children's Hospital Center for Vaccine Development, Departments of Pediatrics and Molecular Virology & Microbiology, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia.
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Kong L, Peng HJ. Current epidemic situation of human toxocariasis in China. ADVANCES IN PARASITOLOGY 2020; 109:433-448. [PMID: 32381211 DOI: 10.1016/bs.apar.2020.01.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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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Rostami A, Ma G, Wang T, Koehler AV, Hofmann A, Chang BCH, Macpherson CN, Gasser RB. Human toxocariasis - A look at a neglected disease through an epidemiological 'prism'. INFECTION GENETICS AND EVOLUTION 2019; 74:104002. [PMID: 31412276 DOI: 10.1016/j.meegid.2019.104002] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 08/07/2019] [Accepted: 08/09/2019] [Indexed: 01/01/2023]
Abstract
Toxocariasis, a disease caused by infection with larvae of Toxocara canis, T. cati and/or congeners, represents clinical syndromes in humans including visceral and ocular larva migrans, neurotoxocariasis and covert/common toxocariasis. It is reported to be one of the most widespread public health and economically important zoonotic parasitic infections that humans share with dogs, wild canids, including foxes, and possibly other mammals. Humans become infected by accidental ingestion of embryonated Toxocara eggs, or larvae from tissues from domestic or wild paratenic hosts. Most infections are asymptomatic, and human disease may go unnoticed, as clinical investigation is often not pursued and/or diagnostic testing not conducted. Sometimes toxocariasis can be associated with complications, such as allergic and/or neurological disorders, possibly including cognitive or developmental delays in children. There is no anti-toxocariasis vaccine, and chemotherapy in humans varies, depending on symptoms and location of larvae, and may include the administration of albendazole or mebendazole, together with anti-inflammatory corticosteroids. Some recent studies indicate that toxocariasis is having an increased, adverse impact on human health in some, particularly underprivileged, tropical and subtropical communities around the world. Although tens of millions of people, especially children, are expected to be exposed to, or infected with Toxocara species, there is limited precise epidemiological data or information on the relationship between seropositivity and disease (toxocariasis) on a global scale. To gain an improved insight into this area, the present article reviews salient clinical aspects of human toxocariasis and the epidemiology of this disease, with particular reference to seroprevalence, and discusses future research and approaches/measures to understand and prevent/control this socioeconomically important, yet neglected zoonosis.
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Affiliation(s)
- Ali Rostami
- Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Guangxu Ma
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Tao Wang
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Anson V Koehler
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Andreas Hofmann
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Bill C H Chang
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Calum N Macpherson
- School of Graduate Studies, St. George's University, Grenada; School of Veterinary Medicine, St. George's University, Grenada; Windward Islands Research and Education Foundation, Grenada
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia.
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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: 0.6] [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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Ma G, Wang T, Korhonen PK, Nie S, Reid GE, Stroehlein AJ, Koehler AV, Chang BCH, Hofmann A, Young ND, Gasser RB. Comparative bioinformatic analysis suggests that specific dauer-like signalling pathway components regulate Toxocara canis development and migration in the mammalian host. Parasit Vectors 2019; 12:32. [PMID: 30642380 PMCID: PMC6332619 DOI: 10.1186/s13071-018-3265-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 12/12/2018] [Indexed: 01/28/2023] Open
Abstract
Background Toxocara canis is quite closely related to Ascaris suum but its biology is more complex, involving a phase of arrested development (diapause or hypobiosis) in tissues as well as transplacental and transmammary transmission routes. In the present study, we explored and compared dauer-like signalling pathways of T. canis and A. suum to infer which components in these pathways might associate with, or regulate, this added complexity in T. canis. Methods Guided by information for Caenorhabditis elegans, we bioinformatically inferred and compared components of dauer-like signalling pathways in T. canis and A. suum using genomic and transcriptomic data sets. In these two ascaridoids, we also explored endogenous dafachronic acids (DAs), which are known to be critical in regulating larval developmental processes in C. elegans and other nematodes, by liquid chromatography-mass spectrometry (LC-MS). Results Orthologues of C. elegans dauer signalling genes were identified in T. canis (n = 55) and A. suum (n = 51), inferring the presence of a dauer-like signalling pathway in both species. Comparisons showed clear differences between C. elegans and these ascaridoids as well as between T. canis and A. suum, particularly in the transforming growth factor-β (TGF-β) and insulin-like signalling pathways. Specifically, in both A. suum and T. canis, there was a paucity of genes encoding SMAD transcription factor-related protein (daf-3, daf-5, daf-8 and daf-14) and insulin/insulin-like peptide (daf-28, ins-4, ins-6 and ins-7) homologues, suggesting an evolution and adaptation of the signalling pathway in these parasites. In T. canis, there were more orthologues coding for homologues of antagonist insulin-like peptides (Tc-ins-1 and Tc-ins-18), an insulin receptor substrate (Tc-ist-1) and a serine/threonine kinase (Tc-akt-1) than in A. suum, suggesting potentiated functional roles for these molecules in regulating larval diapause and reactivation. A relatively conserved machinery was proposed for DA synthesis in the two ascaridoids, and endogenous Δ4- and Δ7-DAs were detected in them by LC-MS analysis. Differential transcription analysis between T. canis and A. suum suggests that ins-17 and ins-18 homologues are specifically involved in regulating development and migration in T. canis larvae in host tissues. Conclusion The findings of this study provide a basis for functional explorations of insulin-like peptides, signalling hormones (i.e. DAs) and related nuclear receptors, proposed to link to development and/or parasite-host interactions in T. canis. Elucidating the functional roles of these molecules might contribute to the discovery of novel anthelmintic targets in ascaridoids. Electronic supplementary material The online version of this article (10.1186/s13071-018-3265-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Guangxu Ma
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Tao Wang
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Pasi K Korhonen
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Shuai Nie
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Gavin E Reid
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Andreas J Stroehlein
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Anson V Koehler
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Bill C H Chang
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Andreas Hofmann
- Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland, 4111, Australia
| | - Neil D Young
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, 3010, Australia.
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Moura MQD, Macedo MRPD, Terto WDDS, Avila LFDC, Leivas Leite FP, Scaini CJ, Pinto NB, Capella GDA, Strothmann AL, Villela MM, Berne MEA. Detection of Toxocara canis DNA in tissues of experimentally infected mice. Acta Trop 2018; 187:51-56. [PMID: 30053384 DOI: 10.1016/j.actatropica.2018.07.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 07/12/2018] [Accepted: 07/23/2018] [Indexed: 01/20/2023]
Abstract
The main etiological agent of toxocariasis is the helminth Toxocara canis. Several difficulties are found in the diagnosis of this disease, because of nonspecific clinical signs and possible cross-reactions that may occur in the available test, the indirect ELISA. Therefore, molecular diagnosis has been indicated as an alternative to conventional diagnosis. The purpose of this study was to evaluate the polymerase chain reaction (PCR) technique for the identification of T. canis in tissues of experimentally infected mice. To this end, nine mice were inoculated with 1500 embryonated eggs and were divided into two groups, the first euthanized 48 h (G1) and the other 30 days post inoculation (G2). Lungs, brain, liver and blood were collected from all the animals for DNA Extraction and tissue digestion, also was collected blood samples for DNA extraction and ELISA test (serum). Toxocara canis DNA was identified in all the inoculated animals using the ITS-2 target gene. The PCR test successfully identified the parasite in the brain, lung and liver of the animals euthanized 48 h PI and 30 days PI. This technique yielded good results in the identification of the parasite in the brain, being more sensitive than the method for the recovery of larvae, in the group with acute infection (48 h PI). The infection was confirmed by PCR within 48 h after infection, while the ELISA indicated serological conversion occurred only 14 days after inoculation. This study demonstrates the ability of PCR to identify T. canis in the liver, lungs and brain during acute and chronic infection.
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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: 105] [Impact Index Per Article: 17.5] [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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Ma G, Holland CV, Wang T, Hofmann A, Fan CK, Maizels RM, Hotez PJ, Gasser RB. Human toxocariasis. THE LANCET. INFECTIOUS DISEASES 2018; 18:e14-e24. [PMID: 28781085 DOI: 10.1016/s1473-3099(17)30331-6] [Citation(s) in RCA: 251] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/21/2017] [Accepted: 05/11/2017] [Indexed: 12/25/2022]
Abstract
Parasitic nematodes of the genus Toxocara are socioeconomically important zoonotic pathogens. These parasites are usually directly transmitted to the human host via the faecal-oral route and can cause toxocariasis and associated complications, including allergic and neurological disorders. Although tens of millions of people are estimated to be exposed to or infected with Toxocara spp, global epidemiological information on the relationship between seropositivity and toxocariasis is limited. Recent findings suggest that the effect of toxocariasis on human health is increasing in some countries. Here we review the salient background on Toxocara and biology, summarise key aspects of the pathogenesis, diagnosis, and treatment of toxocariasis, describe what is known about its geographic distribution and prevalence, and make some recommendations for future research towards the prevention and control of this important disease.
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Affiliation(s)
- Guangxu Ma
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, Australia
| | - Celia V Holland
- Department of Zoology, School of Natural Sciences, Trinity College, Dublin, Ireland
| | - Tao Wang
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, Australia
| | - Andreas Hofmann
- Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, Australia
| | - Chia-Kwung Fan
- Department of Molecular Parasitology and Tropical Diseases, School of Medicine & Research Center of International Tropical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Rick M Maizels
- Wellcome Centre for Molecular Parasitology, Institute for Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Peter J Hotez
- Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Molecular Virology & Microbiology, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, Australia.
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Leahy E, Bronsvoort B, Gamble L, Gibson A, Kaponda H, Mayer D, Mazeri S, Shervell K, Sargison N. Proof of concept of faecal egg nematode counting as a practical means of veterinary engagement with planned livestock health management in a lower income country. Ir Vet J 2017; 70:16. [PMID: 28588763 PMCID: PMC5457739 DOI: 10.1186/s13620-017-0094-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 05/30/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The wellbeing and livelihood of farmers in impoverished regions of the world is intrinsically linked to the health and welfare of their livestock; hence improved animal health is a pragmatic component of poverty alleviation. Prerequisite knowledge and understanding of the animal health challenges facing cattle keepers in Malawi is constrained by the lack of veterinary infrastructure, which inevitably accompanies under-resourced rural development in a poor country. METHODS We collaborated with public and private paraveterinary services to locate 62 village Zebu calves and 60 dairy co-operative calves dispersed over a wide geographical area. All calves were visited twice about 2 to 3 weeks apart, when they were clinically examined and faecal samples were collected. The calves were treated with 7.5 mg/kg of a locally-available albendazole drench on the first visit, and pre- and post- treatment trichostrongyle and Toxocara faecal egg counts were performed using a modified McMaster method. RESULTS Our clinical findings point towards a generally poor level of animal health, implying a role of ticks and tick-transmitted diseases in village calves and need for improvement in neonatal calf husbandry in the dairy co-operative holdings. High faecal trichostrongyle egg counts were not intuitive, based on our interpretation of the animal management information that was provided. This shows the need for better understanding of nematode parasite epidemiology within the context of local husbandry and environmental conditions. The albendazole anthelmintic was effective against Toxocara, while efficacy against trichostrongyle nematodes was poor in both village and dairy co-operative calves, demonstrating the need for further research to inform sustainable drug use. CONCLUSIONS Here we describe the potential value of faecal nematode egg counting as a platform for communicating with and gaining access to cattle keepers and their animals, respectively, in southern Malawi, with the aim of providing informative background knowledge and understanding that may aid in the establishment of effective veterinary services in an under-resourced community.
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Affiliation(s)
- Eithne Leahy
- Worldwide Veterinary Service, 14 Wimborne Street, Cranborne, Dorset BH21 5PP UK
| | - Barend Bronsvoort
- Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, University of Edinburgh, Roslin, Midlothian EH25 9RG UK.,The Epidemiology, Economics and Risk Assessment (EERA) Group, The Roslin Institute, Easter Bush, Roslin, Midlothian EH26 9RG UK
| | - Luke Gamble
- Worldwide Veterinary Service, 14 Wimborne Street, Cranborne, Dorset BH21 5PP UK
| | | | - Henderson Kaponda
- Blantyre District Agricultural Development Office, Kunthembwe EPA, Malawi
| | - Dagmar Mayer
- Worldwide Veterinary Service, 14 Wimborne Street, Cranborne, Dorset BH21 5PP UK
| | - Stella Mazeri
- Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, University of Edinburgh, Roslin, Midlothian EH25 9RG UK.,The Epidemiology, Economics and Risk Assessment (EERA) Group, The Roslin Institute, Easter Bush, Roslin, Midlothian EH26 9RG UK
| | | | - Neil Sargison
- Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, University of Edinburgh, Roslin, Midlothian EH25 9RG UK
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Nascimento Santos L, Carvalho Pacheco LG, Silva Pinheiro C, Alcantara-Neves NM. Recombinant proteins of helminths with immunoregulatory properties and their possible therapeutic use. Acta Trop 2017; 166:202-211. [PMID: 27871775 DOI: 10.1016/j.actatropica.2016.11.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 11/13/2016] [Accepted: 11/15/2016] [Indexed: 02/06/2023]
Abstract
The inverse relationship between helminth infections and the development of immune-mediated diseases is a cornerstone of the hygiene hypothesis and studies were carried out to elucidate the mechanisms by which helminth-derived molecules can suppress immunological disorders. These studies have fostered the idea that parasitic worms may be used as a promising therapeutic alternative for prevention and treatment of immune-mediated diseases. We discuss the current approaches for identification of helminth proteins with potential immunoregulatory properties, including the strategies based on high-throughput technologies. We also explore the methodological approaches and expression systems used for production of the recombinant forms of more than 20 helminth immunomodulatory proteins, besides their performances when evaluated as immunotherapeutic molecules to treat different immune-mediated conditions, including asthma and inflammatory bowel diseases. Finally, we discuss the perspectives of using these parasite-derived recombinant molecules as tools for future immunotherapy and immunoprophylaxis of human inflammatory diseases.
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Zhou RQ, Ma GX, Korhonen PK, Luo YL, Zhu HH, Luo YF, Gasser RB, Xia QY. Comparative transcriptomic analyses of male and female adult Toxocara canis. Gene 2017; 600:85-89. [DOI: 10.1016/j.gene.2016.11.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 10/17/2016] [Accepted: 11/10/2016] [Indexed: 12/22/2022]
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Sperotto RL, Kremer FS, Aires Berne ME, Costa de Avila LF, da Silva Pinto L, Monteiro KM, Caumo KS, Ferreira HB, Berne N, Borsuk S. Proteomic analysis of Toxocara canis excretory and secretory (TES) proteins. Mol Biochem Parasitol 2016; 211:39-47. [PMID: 27638150 DOI: 10.1016/j.molbiopara.2016.09.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 09/09/2016] [Accepted: 09/12/2016] [Indexed: 11/29/2022]
Abstract
Toxocariasis is a neglected disease, and its main etiological agent is the nematode Toxocara canis. Serological diagnosis is performed by an enzyme-linked immunosorbent assay using T. canis excretory and secretory (TES) antigens produced by in vitro cultivation of larvae. Identification of TES proteins can be useful for the development of new diagnostic strategies since few TES components have been described so far. Herein, we report the results obtained by proteomic analysis of TES proteins using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach. TES fractions were separated by one-dimensional SDS-PAGE and analyzed by LC-MS/MS. The MS/MS spectra were compared with a database of protein sequences deduced from the genome sequence of T. canis, and a total of 19 proteins were identified. Classification according to the signal peptide prediction using the SignalP server showed that seven of the identified proteins were extracellular, 10 had cytoplasmic or nuclear localization, while the subcellular localization of two proteins was unknown. Analysis of molecular functions by BLAST2GO showed that the majority of the gene ontology (GO) terms associated with the proteins present in the TES sample were associated with binding functions, including but not limited to protein binding (GO:0005515), inorganic ion binding (GO:0043167), and organic cyclic compound binding (GO:0097159). This study provides additional information about the exoproteome of T. canis, which can lead to the development of new strategies for diagnostics or vaccination.
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Affiliation(s)
- Rita Leal Sperotto
- Departamento de Microbiologia e Parasitologia, Universidade Federal de Pelotas (UFPel), Pelotas, Brazil
| | - Frederico Schmitt Kremer
- Laboratório de Biotecnologia Infecto-Parasitária, Centro de Desenvolvimento Tecnológico- UFPel, Pelotas, Brazil
| | | | - Luciana F Costa de Avila
- Departamento de Microbiologia e Parasitologia, Universidade Federal de Pelotas (UFPel), Pelotas, Brazil
| | - Luciano da Silva Pinto
- Laboratório de Biotecnologia Infecto-Parasitária, Centro de Desenvolvimento Tecnológico- UFPel, Pelotas, Brazil
| | - Karina Mariante Monteiro
- Laboratório de Genômica Estrutural e Funcional, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; Departamento de Biologia Molecular e Biotecnologia, Instituto de Biociências, UFRGS, Porto Alegre, Brazil
| | - Karin Silva Caumo
- Laboratório de Genômica Estrutural e Funcional, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; Departamento de Biologia Molecular e Biotecnologia, Instituto de Biociências, UFRGS, Porto Alegre, Brazil
| | - Henrique Bunselmeyer Ferreira
- Laboratório de Genômica Estrutural e Funcional, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; Departamento de Biologia Molecular e Biotecnologia, Instituto de Biociências, UFRGS, Porto Alegre, Brazil
| | - Natália Berne
- Departamento de Microbiologia e Parasitologia, Universidade Federal de Pelotas (UFPel), Pelotas, Brazil
| | - Sibele Borsuk
- Laboratório de Biotecnologia Infecto-Parasitária, Centro de Desenvolvimento Tecnológico- UFPel, Pelotas, Brazil.
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Making sense of genomes of parasitic worms: Tackling bioinformatic challenges. Biotechnol Adv 2016; 34:663-686. [DOI: 10.1016/j.biotechadv.2016.03.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 02/25/2016] [Accepted: 03/01/2016] [Indexed: 01/25/2023]
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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: 3.4] [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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Stroehlein AJ, Young ND, Hall RS, Korhonen PK, Hofmann A, Sternberg PW, Jabbar A, Gasser RB. CAP protein superfamily members in Toxocara canis. Parasit Vectors 2016; 9:360. [PMID: 27342979 PMCID: PMC4921028 DOI: 10.1186/s13071-016-1642-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 06/13/2016] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Proteins of the cysteine-rich secretory proteins, antigen 5 and pathogenesis-related 1 (CAP) superfamily are recognized or proposed to play roles in parasite development and reproduction, and in modulating host immune attack and infection processes. However, little is known about these proteins for most parasites. RESULTS In the present study, we explored CAP proteins of Toxocara canis, a socioeconomically important zoonotic roundworm. To do this, we mined and curated transcriptomic and genomic data, predicted and curated full-length protein sequences (n = 28), conducted analyses of these data and studied the transcription of respective genes in different developmental stages of T. canis. In addition, based on information available for Caenorhabditis elegans, we inferred that selected genes (including lon-1, vap-1, vap-2, scl-1, scl-8 and scl-11 orthologs) of T. canis and their interaction partners likely play central roles in this parasite's development and/or reproduction via TGF-beta and/or insulin-like signaling pathways, or via host interactions. CONCLUSION In conclusion, this study could provide a foundation to guide future studies of CAP proteins of T. canis and related parasites, and might assist in finding new interventions against diseases caused by these parasites.
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Affiliation(s)
- Andreas J Stroehlein
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia.
| | - Neil D Young
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Ross S Hall
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Pasi K Korhonen
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Andreas Hofmann
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia.,Structural Chemistry Program, Eskitis Institute, Griffith University, Brisbane, Australia
| | - Paul W Sternberg
- HHMI and Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Abdul Jabbar
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia.
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Ma G, Luo Y, Zhu H, Luo Y, Korhonen PK, Young ND, Gasser RB, Zhou R. MicroRNAs of Toxocara canis and their predicted functional roles. Parasit Vectors 2016; 9:229. [PMID: 27108220 PMCID: PMC4842261 DOI: 10.1186/s13071-016-1508-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 04/12/2016] [Indexed: 12/21/2022] Open
Abstract
Background Toxocara canis is the causative agent of toxocariasis of humans and other animals. This parasitic nematode (roundworm) has a complex life cycle, in which substantial developmental changes and switches occur. As small non-coding RNAs (sRNAs) are key regulators of gene expression in a wide range of organisms, we explored these RNAs in T. canis to provide a basis for future studies of its developmental biology as well as host interactions and disease at the molecular level. Methods We conducted high-throughput RNA sequencing and bioinformatic analyses to define sRNAs in individual male and female adults of T. canis. Results Apart from snRNA and snoRNA, 560 and 619 microRNAs (miRNAs), including 5 and 2 novel miRNAs, were identified in male and female worms, respectively, without piRNAs being detected in either sex. An analysis of transcriptional profiles showed that, of 564 miRNAs predicted as being differentially transcribed between male and female individuals of T. canis, 218 miRNAs were transcribed exclusively in male and 277 in female worms. Functional enrichment analysis predicted that both male and female miRNAs were mainly involved in regulating embryonic morphogenesis, hemidesmosome assembly and genetic information processing. The miRNAs differentially transcribed between the sexes were predicted to be associated with sex determination, embryonic morphogenesis and nematode larval development. The roles of miRNAs were predicted based on gene ontology (GO) and KEGG pathway annotations. The miRNAs Tc-miR-2305 and Tc-miR-6090 are proposed to have roles in reproduction, embryo development and larval development, and Tc-let-7-5p, Tc-miR-34 and Tc-miR-100 appear to be involved in host-parasite interactions. Together with published information from previous studies, some miRNAs (such as Tc-miR-2861, Tc-miR-2881 and Tc-miR-5126) are predicted to represent drug targets and/or associated with drug resistance. Conclusions This is the first exploration of miRNAs in T. canis, which could provide a basis for fundamental investigations of the developmental biology of the parasite, parasite-host interactions and toxocariasis as well as applied areas, such as the diagnosis of infection/disease, drug target discovery and drug resistance detection. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1508-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Guangxu Ma
- Department of Veterinary Medicine, Rongchang Campus of Southwest University, Chongqing, 402460, The People's Republic of China.,Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Yongfang Luo
- Department of Veterinary Medicine, Rongchang Campus of Southwest University, Chongqing, 402460, The People's Republic of China
| | - Honghong Zhu
- Department of Veterinary Medicine, Rongchang Campus of Southwest University, Chongqing, 402460, The People's Republic of China
| | - Yongli Luo
- Department of Veterinary Medicine, Rongchang Campus of Southwest University, Chongqing, 402460, The People's Republic of China
| | - Pasi K Korhonen
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Neil D Young
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia.
| | - Rongqiong Zhou
- Department of Veterinary Medicine, Rongchang Campus of Southwest University, Chongqing, 402460, The People's Republic of 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: 2.3] [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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Abstract
SUMMARYToxocara species infect a wide range of companion, domestic and wild animals as definitive and paratenic hosts, via multiple routes of transmission, producing long-lived tissue-inhabiting larvae and resistant eggs that can survive in the external environment. Therefore Toxocara and the disease it causes in humans, toxocariasis, represents an ideal aetiological agent for the development of the one health approach. However, despite increasing awareness of the public health significance of toxocariasis, gaps in our understanding of certain key aspects of the parasite's biology and epidemiology remain. These gaps hinder our ability to integrate research effort within the veterinary, medical and environmental disciplines. This review will highlight key deficits in our understanding of nine dimensions of Toxocara epidemiology and discuss a potential scenario to develop a more integrated, one health approach to improve our understanding of the prevention and control of this complex and cryptic zoonosis.
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27
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Ward JD. Rendering the Intractable More Tractable: Tools from Caenorhabditis elegans Ripe for Import into Parasitic Nematodes. Genetics 2015; 201:1279-94. [PMID: 26644478 PMCID: PMC4676526 DOI: 10.1534/genetics.115.182717] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 10/20/2015] [Indexed: 12/14/2022] Open
Abstract
Recent and rapid advances in genetic and molecular tools have brought spectacular tractability to Caenorhabditis elegans, a model that was initially prized because of its simple design and ease of imaging. C. elegans has long been a powerful model in biomedical research, and tools such as RNAi and the CRISPR/Cas9 system allow facile knockdown of genes and genome editing, respectively. These developments have created an additional opportunity to tackle one of the most debilitating burdens on global health and food security: parasitic nematodes. I review how development of nonparasitic nematodes as genetic models informs efforts to import tools into parasitic nematodes. Current tools in three commonly studied parasites (Strongyloides spp., Brugia malayi, and Ascaris suum) are described, as are tools from C. elegans that are ripe for adaptation and the benefits and barriers to doing so. These tools will enable dissection of a huge array of questions that have been all but completely impenetrable to date, allowing investigation into host-parasite and parasite-vector interactions, and the genetic basis of parasitism.
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Affiliation(s)
- Jordan D Ward
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94158
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28
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Poulsen CS, Skov S, Yoshida A, Skallerup P, Maruyama H, Thamsborg SM, Nejsum P. Differential serodiagnostics ofToxocara canisandToxocara cati- is it possible? Parasite Immunol 2015; 37:204-7. [DOI: 10.1111/pim.12181] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 02/17/2015] [Indexed: 11/29/2022]
Affiliation(s)
- C. S. Poulsen
- Department of Veterinary Disease Biology; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
| | - S. Skov
- Department of Veterinary Disease Biology; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
| | - A. Yoshida
- Division of Parasitology; Faculty of Medicine; University of Miyazaki; Miyazaki Japan
| | - P. Skallerup
- Department of Veterinary Disease Biology; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
| | - H. Maruyama
- Division of Parasitology; Faculty of Medicine; University of Miyazaki; Miyazaki Japan
| | - S. M. Thamsborg
- Department of Veterinary Disease Biology; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
| | - P. Nejsum
- Department of Veterinary Disease Biology; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
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29
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Zhu XQ, Korhonen PK, Cai H, Young ND, Nejsum P, von Samson-Himmelstjerna G, Boag PR, Tan P, Li Q, Min J, Yang Y, Wang X, Fang X, Hall RS, Hofmann A, Sternberg PW, Jex AR, Gasser RB. Genetic blueprint of the zoonotic pathogen Toxocara canis. Nat Commun 2015; 6:6145. [PMID: 25649139 PMCID: PMC4327413 DOI: 10.1038/ncomms7145] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Accepted: 12/11/2014] [Indexed: 11/09/2022] Open
Abstract
Toxocara canis is a zoonotic parasite of major socioeconomic importance worldwide. In humans, this nematode causes disease (toxocariasis) mainly in the under-privileged communities in developed and developing countries. Although relatively well studied from clinical and epidemiological perspectives, to date, there has been no global investigation of the molecular biology of this parasite. Here we use next-generation sequencing to produce a draft genome and transcriptome of T. canis to support future biological and biotechnological investigations. This genome is 317 Mb in size, has a repeat content of 13.5% and encodes at least 18,596 protein-coding genes. We study transcription in a larval, as well as adult female and male stages, characterize the parasite’s gene-silencing machinery, explore molecules involved in development or host–parasite interactions and predict intervention targets. The draft genome of T. canis should provide a useful resource for future molecular studies of this and other, related parasites. Toxocara canis is a zoonotic parasite of major worldwide socioeconomic importance. Here, the authors sequence the genome and transcriptome of T. canis, and highlight potential mechanisms involved in development and host–parasite interactions that could support the pursuit of new drug interventions.
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Affiliation(s)
- Xing-Quan Zhu
- 1] 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 730046, Gansu Province, China [2] Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria 3010, Australia
| | - Pasi K Korhonen
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria 3010, Australia
| | | | - Neil D Young
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria 3010, Australia
| | - Peter Nejsum
- Department of Veterinary Disease Biology, University of Copenhagen, Copenhagen 2200, Denmark
| | | | - Peter R Boag
- Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Patrick Tan
- 1] Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore 138672, Republic of Singapore [2] Genome Institute of Singapore, 60 Biopolis Street, Singapore 138672, Republic of Singapore
| | | | | | | | | | | | - Ross S Hall
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria 3010, Australia
| | - Andreas Hofmann
- Structural Chemistry Program, Eskitis Institute, Griffith University, Brisbane 4111, Queensland, Australia
| | - Paul W Sternberg
- HHMI, Division of Biology, California Institute of Technology, Pasadena 91125, California, USA
| | - Aaron R Jex
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria 3010, Australia
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria 3010, Australia
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30
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Beveridge I, Gasser RB. Diversity in parasitic helminths of Australasian marsupials and monotremes: a molecular perspective. Int J Parasitol 2014; 44:859-64. [DOI: 10.1016/j.ijpara.2014.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 06/09/2014] [Accepted: 06/10/2014] [Indexed: 11/25/2022]
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31
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Jabbar A, Littlewood DTJ, Mohandas N, Briscoe AG, Foster PG, Müller F, von Samson-Himmelstjerna G, Jex AR, Gasser RB. The mitochondrial genome of Parascaris univalens--implications for a "forgotten" parasite. Parasit Vectors 2014; 7:428. [PMID: 25190631 PMCID: PMC4262126 DOI: 10.1186/1756-3305-7-428] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 09/01/2014] [Indexed: 11/12/2022] Open
Abstract
Background Parascaris univalens is an ascaridoid nematode of equids. Little is known about its epidemiology and population genetics in domestic and wild horse populations. PCR-based methods are suited to support studies in these areas, provided that reliable genetic markers are used. Recent studies have shown that mitochondrial (mt) genomic markers are applicable in such methods, but no such markers have been defined for P. univalens. Methods Mt genome regions were amplified from total genomic DNA isolated from P. univalens eggs by long-PCR and sequenced using Illumina technology. The mt genome was assembled and annotated using an established bioinformatic pipeline. Amino acid sequences inferred from all protein-encoding genes of the mt genomes were compared with those from other ascaridoid nematodes, and concatenated sequences were subjected to phylogenetic analysis by Bayesian inference. Results The circular mt genome was 13,920 bp in length and contained two ribosomal RNA, 12 protein-coding and 22 transfer RNA genes, consistent with those of other ascaridoids. Phylogenetic analysis of the concatenated amino acid sequence data for the 12 mt proteins showed that P. univalens was most closely related to Ascaris lumbricoides and A. suum, to the exclusion of other ascaridoids. Conclusions This mt genome representing P. univalens now provides a rich source of genetic markers for future studies of the genetics and epidemiology of this parasite and its congener, P. equorum. This focus is significant, given that there is no published information on the specific prevalence and distribution of P. univalens infection in domestic and wild horse populations. Electronic supplementary material The online version of this article (doi:10.1186/1756-3305-7-428) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Abdul Jabbar
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, Victoria, Australia.
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Jabbar A, Gasser RB. Mutation scanning analysis of genetic variation within and among Echinococcus species: implications and future prospects. Electrophoresis 2014; 34:1852-62. [PMID: 23977679 DOI: 10.1002/elps.201300078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Adult tapeworms of the genus Echinococcus (family Taeniidae) occur in the small intestines of carnivorous definitive hosts and are transmitted to particular intermediate mammalian hosts, in which they develop as fluid-filled larvae (cysts) in internal organs (usually lung and liver), causing the disease echinococcosis. Echinococcus species are of major medical importance and also cause losses to the meat and livestock industries, mainly due to the condemnation of infected offal. Decisions regarding the treatment and control of echinococcosis rely on the accurate identification of species and population variants (strains). Conventional, phenetic methods for specific identification have some significant limitations. Despite advances in the development of molecular tools, there has been limited application of mutation scanning methods to species of Echinococcus. Here, we briefly review key genetic markers used for the identification of Echinococcus species and techniques for the analysis of genetic variation within and among populations, and the diagnosis of echinococcosis. We also discuss the benefits of utilizing mutation scanning approaches to elucidate the population genetics and epidemiology of Echinococcus species. These benefits are likely to become more evident following the complete characterization of the genomes of E. granulosus and E. multilocularis.
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Affiliation(s)
- Abdul Jabbar
- Faculty of Veterinary Science, The University of Melbourne, Parkville, Victoria, Australia
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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: 24.0] [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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Roeber F, Jex AR, Gasser RB. Impact of gastrointestinal parasitic nematodes of sheep, and the role of advanced molecular tools for exploring epidemiology and drug resistance - an Australian perspective. Parasit Vectors 2013; 6:153. [PMID: 23711194 PMCID: PMC3679956 DOI: 10.1186/1756-3305-6-153] [Citation(s) in RCA: 195] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 04/11/2013] [Indexed: 11/10/2022] Open
Abstract
Parasitic nematodes (roundworms) of small ruminants and other livestock have major economic impacts worldwide. Despite the impact of the diseases caused by these nematodes and the discovery of new therapeutic agents (anthelmintics), there has been relatively limited progress in the development of practical molecular tools to study the epidemiology of these nematodes. Specific diagnosis underpins parasite control, and the detection and monitoring of anthelmintic resistance in livestock parasites, presently a major concern around the world. The purpose of the present article is to provide a concise account of the biology and knowledge of the epidemiology of the gastrointestinal nematodes (order Strongylida), from an Australian perspective, and to emphasize the importance of utilizing advanced molecular tools for the specific diagnosis of nematode infections for refined investigations of parasite epidemiology and drug resistance detection in combination with conventional methods. It also gives a perspective on the possibility of harnessing genetic, genomic and bioinformatic technologies to better understand parasites and control parasitic diseases.
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Affiliation(s)
| | - Aaron R Jex
- The University of Melbourne, Victoria 3010, Australia
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Koehler AV, Bradbury RS, Stevens MA, Haydon SR, Jex AR, Gasser RB. Genetic characterization of selected parasites from people with histories of gastrointestinal disorders using a mutation scanning-coupled approach. Electrophoresis 2013; 34:1720-8. [PMID: 23592267 DOI: 10.1002/elps.201300100] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 03/21/2013] [Accepted: 03/22/2013] [Indexed: 11/11/2022]
Abstract
A SSCP analysis and targeted sequencing approach was used for the genetic characterization of some major pathogens from a cohort of 227 people with histories of gastrointestinal disorders. Genomic DNAs from fecal samples were subjected to PCR-amplification of regions in the glycoprotein (gp60) or triose phosphate isomerase (tpi) gene, or the second internal transcribed spacer of nuclear ribosomal DNA (ITS-2). Cryptosporidium, Giardia, and strongylid nematodes were detected in 94, 132 and 12 samples. Cryptosporidium hominis subgenotypes IbA10G2, IdA15G1, IgA17, IgA18, and IfA13G1 were identified in 74.6, 16.9, 5.6, 1.4, and 1.4% of 71 samples, respectively. For Cryptosporidium parvum, subgenotypes IIaA17G2R1 (47.6%) and IIaA18G3R1 (23.8%) were identified in 23 samples. Giardia duodenalis assemblage B (78%) was more common than assemblage A (22%). In addition, DNA of the nematodes Ancylostoma ceylanicum (n = 2), Ancylostoma duodenale (4), Necator americanus (5), and Haemonchus contortus (1) was specifically detected. This is the first report of A. ceylanicum in two persons in Australia and, we provide molecular evidence of H. contortus in a child. This SSCP-based approach should provide a useful diagnostic and analytical tool for a wide range of pathogens.
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Affiliation(s)
- Anson V Koehler
- Faculty of Veterinary Science, University of Melbourne, Victoria, Australia.
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36
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Abstract
Toxocara canis has extraordinary abilities to survive for many years in the tissues of diverse vertebrate species, as well as to develop to maturity in the intestinal tract of its definitive canid host. Human disease is caused by larval stages invading musculature, brain and the eye, and immune mechanisms appear to be ineffective at eliminating the infection. Survival of T. canis larvae can be attributed to two molecular strategies evolved by the parasite. Firstly, it releases quantities of 'excretory-secretory' products which include lectins, mucins and enzymes that interact with and modulate host immunity. For example, one lectin (CTL-1) is very similar to mammalian lectins, required for tissue inflammation, suggesting that T. canis may interfere with leucocyte extravasation into infected sites. The second strategy is the elaboration of a specialised mucin-rich surface coat; this is loosely attached to the parasite epicuticle in a fashion that permits rapid escape when host antibodies and cells adhere, resulting in an inflammatory reaction around a newly vacated focus. The mucins have been characterised as bearing multiple glycan side-chains, consisting of a blood-group-like trisaccharide with one or two O-methylation modifications. Both the lectins and these trisaccharides are targeted by host antibodies, with anti-lectin antibodies showing particular diagnostic promise. Antibodies to the mono-methylated trisaccharide appear to be T. canis-specific, as this epitope is not found in the closely related Toxocara cati, but all other antigenic determinants are very similar between the two species. This distinction may be important in designing new and more accurate diagnostic tests. Further tools to control toxocariasis could also arise from understanding the molecular cues and steps involved in larval development. In vitro-cultivated larvae express high levels of four mRNAs that are translationally silenced, as the proteins they encode are not detectable in cultured larvae. However, these appear to be produced once the parasite has entered the mammalian host, as they are recognised by specific antibodies in infected patients. Elucidating the function of these genes, or analysing if micro-RNA translational silencing suppresses production of the proteins, may point towards new drug targets for tissue-phase parasites in humans.
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Affiliation(s)
- Rick M Maizels
- Institute of Immunology and Infection Research, University of Edinburgh, Ashworth Laboratories, West Mains Road, Edinburgh EH9 3JT, United Kingdom.
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