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Robinson S, Falinski K, Johnson D, VanWormer E, Shapiro K, Amlin A, Barbieri M. Evaluating the Risk Landscape of Hawaiian Monk Seal Exposure to Toxoplasma gondii. ECOHEALTH 2024:10.1007/s10393-024-01678-7. [PMID: 38850367 DOI: 10.1007/s10393-024-01678-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 03/02/2024] [Accepted: 03/06/2024] [Indexed: 06/10/2024]
Abstract
Toxoplasmosis is a disease of primary concern for Hawaiian monk seals (Neomonachus schauinslandi), due to its apparently acute lethality and especially heavy impacts on breeding female seals. The disease-causing parasite, Toxoplasma gondii, depends on cats to complete its life cycle; thus, in order to understand how this pathogen infects marine mammals, it is essential to understand aspects of the terrestrial ecosystem and land-to-sea transport. In this study, we constructed a three-tiered model to assess risk of Hawaiian monk seal exposure to T. gondii oocysts: (1) oocyst contamination as a function of cat population characteristics; (2) land-to-sea transport of oocysts as a function of island hydrology, and (3) seal exposure as a function of habitat and space use. We were able to generate risk maps highlighting watersheds contributing the most to oocyst contamination of Hawaiian monk seal habitat. Further, the model showed that free-roaming cats most associated with humans (pets or strays often supplementally fed by people) were able to achieve high densities leading to high levels of oocyst contamination and elevated risk of T. gondii exposure.
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Affiliation(s)
| | - Kim Falinski
- UH, Water Resources Research Center, Honolulu, USA
| | | | | | | | - Angela Amlin
- NOAA, Pacific Islands Regional Office, Honolulu, USA
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2
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Dawant T, Wang W, Spriggs M, Magela de Faria Junior G, Horton L, Szafranski NM, Waap H, Jokelainen P, Gerhold RW, Su C. Isolation of Toxoplasma gondii in cell culture: an alternative to bioassay. Int J Parasitol 2024; 54:131-137. [PMID: 38097034 DOI: 10.1016/j.ijpara.2023.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 10/24/2023] [Accepted: 12/06/2023] [Indexed: 01/21/2024]
Abstract
Toxoplasma gondii is an apicomplexan protozoan parasite that can infect mammals and birds. The infection can cause acute toxoplasmosis and death in susceptible hosts. Bioassay using cats and mice has been the standard for the isolation of T. gondii from infected hosts for the past several decades. However, bioassay is labor-intensive, expensive, and involves using laboratory animals. To search alternative approaches and o work towards replacement of animal experiments, we summarized the key literature and conducted four experiments to isolate T. gondii in vitro by cell culture. A few heart tissue samples from animals with the highest antibody titers in a given collection were used for T. gondii isolation. These experiments included samples from five out of 51 wild ducks, four of 46 wild turkeys, six of 24 white-tailed deer, as well as from six kangaroos that had died with acute toxoplasmosis in a zoo. These experiments resulted in three isolates from five chronically infected wild ducks (60%), four isolates from four chronically infected wild turkeys (100%), one isolate from six chronically infected white-tailed deer (17%), and four isolates from six kangaroos with acute toxoplasmosis (67%). In addition, five isolates from the five chronically infected wild ducks were obtained by bioassay in mice, showing a 100% success rate, which is higher than the 60% rate by direct cell culture. These T. gondii isolates were successfully propagated in human foreskin fibroblast (HFF) or Vero cells, and genotyped by multilocus PCR-RFLP markers. The results showed that it is practical to isolate T. gondii directly in cell culture. Although the cell culture approach may not be as sensitive as the bioassay, it does provide an alternative that is simple, cost-effective, ethically more acceptable, and less time-sensitive to isolate T. gondii. In this paper we propose a procedure that may be applied and further optimized for isolation of T. gondii.
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Affiliation(s)
- Tania Dawant
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN. USA
| | - Wei Wang
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA
| | - Maria Spriggs
- SeaWorld Parks and Entertainment, Busch Gardens, 3605 E. Bougainvillea Avenue, Tampa, Florida 33612, USA
| | | | - Laura Horton
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN. USA
| | - Nicole M Szafranski
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN. USA
| | - Helga Waap
- Laboratório de Parasitologia, Unidade Estratégica de Investigação e Serviços, de Produção e Saúde Anima (UEISPSA), Portugal; Animal Behaviour and Welfare Laboratory, Centre of Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, Lisbon University, Lisbon, Portugal; Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), Lisbon, Portugal; Centre for Infectious Disease Control-Zoonoses and Environmental Microbiology, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Pikka Jokelainen
- Infectious Disease Preparedness, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen, Denmark
| | - Richard W Gerhold
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN. USA
| | - Chunlei Su
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA.
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3
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Zhu S, Camp L, Patel A, VanWormer E, Shapiro K. High prevalence and diversity of Toxoplasma gondii DNA in feral cat feces from coastal California. PLoS Negl Trop Dis 2023; 17:e0011829. [PMID: 38100522 PMCID: PMC10756541 DOI: 10.1371/journal.pntd.0011829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 12/29/2023] [Accepted: 11/30/2023] [Indexed: 12/17/2023] Open
Abstract
Toxoplasma gondii is a zoonotic parasite that can cause severe morbidity and mortality in warm-blooded animals, including marine mammals such as sea otters. Free-ranging cats can shed environmentally resistant T. gondii oocysts in their feces, which are transported through rain-driven runoff from land to sea. Despite their large population sizes and ability to contribute to environmental oocyst contamination, there are limited studies on T. gondii oocyst shedding by free-ranging cats. We aimed to determine the frequency and genotypes of T. gondii oocysts shed by free-ranging domestic cats in central coastal California and evaluate whether genotypes present in feces are similar to those identified in sea otters that died from fatal toxoplasmosis. We utilized a longitudinal field study of four free-ranging cat colonies to assess oocyst shedding prevalence using microscopy and molecular testing with polymerase chain reaction (PCR). T. gondii DNA was confirmed with primers targeting the ITS1 locus and positive samples were genotyped at the B1 locus. While oocysts were not visualized using microscopy (0/404), we detected T. gondii DNA in 25.9% (94/362) of fecal samples. We genotyped 27 samples at the B1 locus and characterized 13 of these samples at one to three additional loci using multi locus sequence typing (MLST). Parasite DNA detection was significantly higher during the wet season (16.3%, 59/362) compared to the dry season (9.7%; 35/362), suggesting seasonal variation in T. gondii DNA presence in feces. High diversity of T. gondii strains was characterized at the B1 locus, including non-archetypal strains previously associated with sea otter mortalities. Free-ranging cats may thus play an important role in the transmission of virulent T. gondii genotypes that cause morbidity and mortality in marine wildlife. Management of free-ranging cat colonies could reduce environmental contamination with oocysts and subsequent T. gondii infection in endangered marine mammals and people.
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Affiliation(s)
- Sophie Zhu
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Lauren Camp
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
- Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Anika Patel
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Elizabeth VanWormer
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
- School of Natural Resources, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Karen Shapiro
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
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Ren H, Mao G, Zhang Y, Zhu N, Liang Q, Jiang Y, Yang Y. Isolation and Characterization of a Viable Toxoplasma gondii from Captive Caracal ( Caracal caracal). Pathogens 2023; 12:1412. [PMID: 38133295 PMCID: PMC10747901 DOI: 10.3390/pathogens12121412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/13/2023] [Accepted: 11/22/2023] [Indexed: 12/23/2023] Open
Abstract
Toxoplasma gondii is a widespread protozoan parasite that infects most warm-blooded animals, and felids can serve as intermediate and definitive hosts. Pathological diagnosis and serological and etiological investigations were conducted on a captive caracal (Caracal caracal) carcass collected from China in 2022. Pathological diagnosis revealed that cardiac insufficiency, pulmonary edema, hepatic failure, and renal insufficiency were the causes of the caracal's death. A modified agglutination test (cut-off: 1:25) revealed that IgG antibodies against T. gondii were present in the myocardium juice (1:1600), ascitic fluid (1:3200), and hydropericardium (1:800). A viable T. gondii (TgCaracalCHn2) strain was isolated from the tissue samples (heart, brain, spleen, and skeletal muscle) of this caracal using a mouse bioassay. The genotype of TgCaracalCHn2 was ToxoDB#5 (Type II variant), as determined via RFLP-PCR. The strain was avirulent in Swiss mice and matched the prediction of ROP18 and ROP5 gene alleles of TgCaracalCHn2 (2/2). Mild tissue cysts (203 ± 265) were observed in mice brains after inoculation with TgCaracalCHn2 tachyzoites. ToxoDB#5 is the dominant genotype in North American wildlife, and this is the first documented isolation of T. gondii ToxoDB#5 from China. This indicates that caracal plays an important role in the transmission of this T. gondii genotype.
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Affiliation(s)
- Hongjie Ren
- College of Animal Science, Henan Agricultural University, Zhengzhou 450000, China
| | - Gaohui Mao
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450000, China
| | - Yan Zhang
- College of Animal Science, Henan Agricultural University, Zhengzhou 450000, China
| | - Niuping Zhu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450000, China
| | - Qunchao Liang
- Henan Yinji Jiabao Amusement Park Management Co., Ltd., Zhengzhou 452300, China
| | - Yibao Jiang
- College of Animal Science, Henan Agricultural University, Zhengzhou 450000, China
| | - Yurong Yang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450000, China
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TOXOPLASMA GONDII PREVALENCE, PARTIAL GENOTYPES, AND SPATIAL VARIATION IN NORTH AMERICAN RIVER OTTERS (LONTRA CANADENSIS) IN THE UPPER PENINSULA OF MICHIGAN, USA. J Wildl Dis 2022; 58:869-881. [PMID: 36321926 DOI: 10.7589/jwd-d-22-00021] [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: 02/28/2022] [Accepted: 07/06/2022] [Indexed: 12/05/2022]
Abstract
Toxoplasma gondii is a ubiquitous parasitic protozoan that poses a health threat to wildlife and human health worldwide. Oocysts shed into the environment in felid host feces may persist for several years. Runoff from rainfall and snowmelt may carry the oocysts into waterways. Semiaquatic mammals such as the Northern American river otter (Lontra canadensis) are particularly at risk of exposure, as they may encounter infective stages in both terrestrial and aquatic environments. Despite this risk, only a small number of studies have examined the prevalence of T. gondii in US river otter populations. Tongue tissue was sampled from 124 otters from the Upper Peninsula of Michigan submitted by trappers to the Michigan Department of Natural Resources in the 2018-19 harvest season. Following DNA extraction, a portion of the B1 T. gondii gene was amplified with PCR. A subset of positive samples was genotyped for comparison with known T. gondii sequences. Of the 124 tongue samples, 35 (28%) were positive for T. gondii. Prevalence did not differ significantly between sexes or age classes across the entire study area. Most (53.8%) of the genotyped samples were type 4 (type 12), a genotype commonly found in North American wildlife. Genotypes 127 and 197 were also found. Three clusters of T. gondii prevalence were identified through SaTScan analysis, although they were not significant. When modeling prevalence of T. gondii with covariates at individual otter locations, the top three models included the presence of Sarcocystis, area of exotic plants, area of agriculture, and sex of the otter. Our results suggest that T. gondii is widespread in otter populations in the Upper Peninsula of Michigan.
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Lepczyk CA, Duffy DC, Bird DM, Calver M, Cherkassky D, Cherkassky L, Dickman CR, Hunter D, Jessup D, Longcore T, Loss SR, Loyd KAT, Marra PP, Marzluff JM, Noss RF, Simberloff D, Sizemore GC, Temple SA, van Heezik Y. A science-based policy for managing free-roaming cats. Biol Invasions 2022. [DOI: 10.1007/s10530-022-02888-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Bolais PF, Galal L, Cronemberger C, Pereira FDA, Barbosa ADS, Dib LV, Amendoeira MRR, Dardé ML, Mercier A. Toxoplasma gondii in the faeces of wild felids from the Atlantic Forest, Brazil. Mem Inst Oswaldo Cruz 2022; 117:e210302. [PMID: 35766781 PMCID: PMC9241165 DOI: 10.1590/0074-02760210302] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 03/28/2022] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Toxoplasma gondii is a apicomplexan parasite of virtually all warm-blooded species. All true cats (Felidae) can act as definitive hosts for this parasite by shedding resistant oocysts into the environment. However, the patterns of oocysts shedding are only partially understood in domestic cats and largely unknown in wild felids. OBJECTIVES We carried out molecular analysis of 82 faecal samples from wild felids collected in the Serra dos Órgãos National Park (Parnaso), Rio de Janeiro, Brazil. METHODS We screened samples for T. gondii DNA using a quantitative polymerase chain reaction (qPCR) targeting the 529bp DNA fragment. Polymerase chain reaction (PCR)-positive samples were genotyped using 15 microsatellite markers. RESULTS Only one faecal sample from a Puma yagouaroundi was PCR-positive [cycle threshold (Ct) = 26.88]. This sample was contaminated by a T. gondii strain of BrIII lineage, a common lineage in domestic animals from Brazil. MAIN CONCLUSIONS This first report of T. gondii in faeces of wild South American felids in their natural environment indicates infrequent oocyst shedding and suggests a role of acquired immunity in limiting re-excretion as in domestic cats. The presence of a domestic strain of T. gondii in a faecal sample from a wild felid at very low concentrations (not detected by microscopy) is consistent with the hypothesis of host-parasite co-adaptations limiting the circulation of T. gondii strains between domestic and wild environments.
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Affiliation(s)
- Paula F Bolais
- University of Limoges, Institute of Epidemiology and Tropical Neurology, Epidemiology of Chronic Diseases in Tropical Zone, OmegaHealth, Limoges, France
| | - Lokman Galal
- University of Limoges, Institute of Epidemiology and Tropical Neurology, Epidemiology of Chronic Diseases in Tropical Zone, OmegaHealth, Limoges, France
| | - Cecília Cronemberger
- Instituto Chico Mendes de Conservação da Biodiversidade, Parque Nacional da Serra dos Órgãos, Teresópolis, RJ, Brasil
| | - Fabiane de Aguiar Pereira
- Instituto Chico Mendes de Conservação da Biodiversidade, Parque Nacional da Serra dos Órgãos, Teresópolis, RJ, Brasil
| | - Alynne da Silva Barbosa
- Universidade Federal Fluminense, Instituto Biomédico, Departamento de Microbiologia e Parasitologia, Niterói, RJ, Brasil.,Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Toxoplasmose e Outras Protozooses, Rio de Janeiro, RJ, Brasil
| | - Laís Verdan Dib
- Universidade Federal Fluminense, Instituto Biomédico, Departamento de Microbiologia e Parasitologia, Niterói, RJ, Brasil.,Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Toxoplasmose e Outras Protozooses, Rio de Janeiro, RJ, Brasil
| | - Maria Regina Reis Amendoeira
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Toxoplasmose e Outras Protozooses, Rio de Janeiro, RJ, Brasil
| | - Marie-Laure Dardé
- University of Limoges, Institute of Epidemiology and Tropical Neurology, Epidemiology of Chronic Diseases in Tropical Zone, OmegaHealth, Limoges, France.,Centre Hospitalier-Universitaire Dupuytren, Centre National de Référence, Toxoplasmose/Toxoplasma Biological Centre, Limoges, France
| | - Aurélien Mercier
- University of Limoges, Institute of Epidemiology and Tropical Neurology, Epidemiology of Chronic Diseases in Tropical Zone, OmegaHealth, Limoges, France.,Centre Hospitalier-Universitaire Dupuytren, Centre National de Référence, Toxoplasmose/Toxoplasma Biological Centre, Limoges, France
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8
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Bouchard É, Sharma R, Hernández-Ortiz A, Buhler K, Al-Adhami B, Su C, Fenton H, G-Gouin G, Roth JD, Rodrigues CW, Pamak C, Simon A, Bachand N, Leighton P, Jenkins E. Are foxes (Vulpes spp.) good sentinel species for Toxoplasma gondii in northern Canada? Parasit Vectors 2022; 15:115. [PMID: 35365191 PMCID: PMC8972674 DOI: 10.1186/s13071-022-05229-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/02/2022] [Indexed: 11/10/2022] Open
Abstract
Background In changing northern ecosystems, understanding the mechanisms of transmission of zoonotic pathogens, including the coccidian parasite Toxoplasma gondii, is essential to protect the health of vulnerable animals and humans. As high-level predators and scavengers, foxes represent a potentially sensitive indicator of the circulation of T. gondii in environments where humans co-exist. The objectives of our research were to compare serological and molecular assays to detect T. gondii, generate baseline data on T. gondii antibody and tissue prevalence in foxes in northern Canada, and compare regional seroprevalence in foxes with that in people from recently published surveys across northern Canada. Methods Fox carcasses (Vulpes vulpes/Vulpes lagopus, n = 749) were collected by local trappers from the eastern (Labrador and Québec) and western Canadian Arctic (northern Manitoba, Nunavut, and the Northwest Territories) during the winters of 2015–2019. Antibodies in heart fluid were detected using a commercial enzyme-linked immunosorbent assay. Toxoplasma gondii DNA was detected in hearts and brains using a magnetic capture DNA extraction and real-time PCR assay. Results Antibodies against T. gondii and DNA were detected in 36% and 27% of foxes, respectively. Detection of antibodies was higher in older (64%) compared to younger foxes (22%). More males (36%) than females (31%) were positive for antibodies to T. gondii. Tissue prevalence in foxes from western Nunavik (51%) was higher than in eastern Nunavik (19%). At the Canadian scale, T. gondii exposure was lower in western Inuit regions (13%) compared to eastern Inuit regions (39%), possibly because of regional differences in fox diet and/or environment. Exposure to T. gondii decreased at higher latitude and in foxes having moderate to little fat. Higher mean infection intensity was observed in Arctic foxes compared to red foxes. Fox and human seroprevalence showed similar trends across Inuit regions of Canada, but were less correlated in the eastern sub-Arctic, which may reflect regional differences in human dietary preferences. Conclusions Our study sheds new light on the current status of T. gondii in foxes in northern Canada and shows that foxes serve as a good sentinel species for environmental circulation and, in some regions, human exposure to this parasite in the Arctic. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05229-3.
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Affiliation(s)
- Émilie Bouchard
- Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, SK, Canada. .,Research Group On Epidemiology of Zoonoses and Public Health (GREZOSP), Université de Montréal, Saint-Hyacinthe, QC, Canada.
| | - Rajnish Sharma
- Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Adrián Hernández-Ortiz
- Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Kayla Buhler
- Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Batol Al-Adhami
- Centre for Food-Borne and Animal Parasitology, Saskatoon, SK, Canada
| | - Chunlei Su
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA
| | - Heather Fenton
- Ross University School of Veterinary Medicine, Basseterre, Saint Kitts and Nevis
| | | | - James D Roth
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada
| | | | - Carla Pamak
- Nunatsiavut Research Centre, Nain, NL, Canada
| | - Audrey Simon
- Research Group On Epidemiology of Zoonoses and Public Health (GREZOSP), Université de Montréal, Saint-Hyacinthe, QC, Canada
| | - Nicholas Bachand
- Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Patrick Leighton
- Research Group On Epidemiology of Zoonoses and Public Health (GREZOSP), Université de Montréal, Saint-Hyacinthe, QC, Canada
| | - Emily Jenkins
- Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, SK, Canada
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Li MY, Gao XN, Ma JY, Elsheikha HM, Cong W. A systematic review, meta-analysis and meta-regression of the global prevalence of Toxoplasma gondii infection in wild marine mammals and associations with epidemiological variables. Transbound Emerg Dis 2022; 69:e1213-e1230. [PMID: 35195942 DOI: 10.1111/tbed.14493] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 02/06/2022] [Accepted: 02/20/2022] [Indexed: 11/30/2022]
Abstract
Toxoplasma gondii infection in wild marine mammals is a growing problem and is associated with adverse impacts on marine animal health and public health. This systematic review, meta-analysis and meta-regression estimates the global prevalence of T. gondii infection in wild marine mammals and analyzes the association between T. gondii infection and epidemiological variables. PubMed, Web of Science, Science Direct, China National Knowledge Infrastructure, and Wanfang Data databases were searched until 30 May 2021. Eighty-four studies (n = 14,931 wild marine mammals from 15 families) were identified from literature. The overall pooled prevalence of T. gondii infection was 22.44% (3,848/14,931; 95% confidence interval (CI): 17.29% - 8.04%). The prevalence in adult animals 21.88% (798/3119; 95% CI: 13.40 -31.59) was higher than in the younger age groups. North America had a higher prevalence 29.92% (2756/9243; 95% CI: 21.77 - 38.77) compared with other continents. At the country level, the highest prevalence was found in Spain 44.26% (19/88; 95%CI: 5.21 - 88.54). Regarding climatic variables, the highest prevalence was found in areas with a mean annual temperature >20°C 36.28% (171/562; 95% CI: 6.36 - 73.61) and areas with an annual precipitation >800 mm 26.92% (1341/5042; 95% CI: 18.20 - 36.59). The subgroup and meta-regression analyses showed that study-level covariates, including age, country, continent, and mean temperature, partly explained the between-study heterogeneity. Further studies are needed to investigate the source of terrestrial to aquatic dissemination of T. gondii oocysts, the fate of this parasite in marine habitat and its effects on wild marine mammals. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Man-Yao Li
- Marine College, Shandong University, Weihai, Shandong, 264209, PR China
| | - Xiao-Nan Gao
- Marine College, Shandong University, Weihai, Shandong, 264209, PR China
| | - Jun-Yang Ma
- Marine College, Shandong University, Weihai, Shandong, 264209, PR China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, United Kingdom
| | - Wei Cong
- Marine College, Shandong University, Weihai, Shandong, 264209, PR China
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10
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Wilson AG, Wilson S, Alavi N, Lapen DR. Human density is associated with the increased prevalence of a generalist zoonotic parasite in mammalian wildlife. Proc Biol Sci 2021; 288:20211724. [PMID: 34666519 PMCID: PMC8527198 DOI: 10.1098/rspb.2021.1724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/23/2021] [Indexed: 01/24/2023] Open
Abstract
Macroecological approaches can provide valuable insight into the epidemiology of globally distributed, multi-host pathogens. Toxoplasma gondii is a zoonotic protozoan that infects any warm-blooded animal, including humans, in almost every ecosystem worldwide. There is substantial geographical variation in T. gondii prevalence in wildlife populations and the mechanisms driving this variation are poorly understood. We implemented Bayesian phylogenetic mixed models to determine the association between species' ecology, phylogeny and climatic and anthropogenic factors on T. gondii prevalence. Toxoplasma gondii prevalence data were compiled for free-ranging wild mammal species from 202 published studies, encompassing 45 079 individuals from 54 taxonomic families and 238 species. We found that T. gondii prevalence was positively associated with human population density and warmer temperatures at the sampling location. Terrestrial species had a lower overall prevalence, but there were no consistent patterns between trophic level and prevalence. The relationship between human density and T. gondii prevalence is probably mediated by higher domestic cat abundance and landscape degradation leading to increased environmental oocyst contamination. Landscape restoration and limiting free-roaming in domestic cats could synergistically increase the resiliency of wildlife populations and reduce wildlife and human infection risks from one of the world's most common parasitic infections.
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Affiliation(s)
- Amy G. Wilson
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
- Canadian Wildlife Health Cooperative, Abbotsford, British Columbia, Canada V3G 2M3
| | - Scott Wilson
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
- Environment and Climate Change Canada, Delta, British Columbia, Canada V4 K 3N2 0H3
| | - Niloofar Alavi
- Environment and Climate Change Canada, Ottawa, Ontario, Canada K1S 5B6
| | - David R. Lapen
- Ottawa Research Development Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada K1A 0C6
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11
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Pou S, Dodean RA, Frueh L, Liebman KM, Gallagher RT, Jin H, Jacobs RT, Nilsen A, Stuart DR, Doggett JS, Riscoe MK, Winter RW. A New Scalable Synthesis of ELQ-300, ELQ-316, and other Antiparasitic Quinolones. Org Process Res Dev 2021; 25:1841-1852. [PMID: 35110959 DOI: 10.1021/acs.oprd.1c00099] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The Endochin-Like Quinolone (ELQ) compound class may yield effective, safe treatments for a range of important human and animal afflictions. However, to access the public health potential of this compound series, a synthetic route needed to be devised that lowers costs and is amenable to large scale production. In the new synthetic route described here, a substituted β-keto ester, formed by an Ullmann reaction and subsequent acylation, is reacted with an aniline via a Conrad-Limpach reaction to produce 3-substituted 4(1H)-quinolones such as ELQ-300 and ELQ-316. This synthetic route, the first described to be truly amenable to industrial scale production, is relatively short (5 reaction steps), does not require palladium, chromatographic separation or protecting group chemistry, and may be performed without high vacuum distillation.
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Affiliation(s)
- Sovitj Pou
- VA Portland Healthcare System, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Rozalia A Dodean
- VA Portland Healthcare System, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Lisa Frueh
- VA Portland Healthcare System, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Katherine M Liebman
- VA Portland Healthcare System, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Rory T Gallagher
- Department of Chemistry, Portland State University, 1719 SW 10 Avenue, Portland, Oregon 97201, United States
| | - Haihong Jin
- Medicinal Chemistry Core, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Robert T Jacobs
- Medicines for Malaria Venture, ICC, route de Pré-Bois 20, P.O. Box 1826, 1215 Geneva 15, Switzerland
| | - Aaron Nilsen
- VA Portland Healthcare System, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States.,Medicinal Chemistry Core, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - David R Stuart
- Department of Chemistry, Portland State University, 1719 SW 10 Avenue, Portland, Oregon 97201, United States
| | - J Stone Doggett
- VA Portland Healthcare System, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States.,School of Medicine Division of Infectious Diseases, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Michael K Riscoe
- VA Portland Healthcare System, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States.,Department of Microbiology and Molecular Immunology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Rolf W Winter
- VA Portland Healthcare System, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
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12
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Gering E, Laubach ZM, Weber PSD, Soboll Hussey G, Lehmann KDS, Montgomery TM, Turner JW, Perng W, Pioon MO, Holekamp KE, Getty T. Toxoplasma gondii infections are associated with costly boldness toward felids in a wild host. Nat Commun 2021; 12:3842. [PMID: 34158487 PMCID: PMC8219747 DOI: 10.1038/s41467-021-24092-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 05/18/2021] [Indexed: 01/17/2023] Open
Abstract
Toxoplasma gondii is hypothesized to manipulate the behavior of warm-blooded hosts to promote trophic transmission into the parasite's definitive feline hosts. A key prediction of this hypothesis is that T. gondii infections of non-feline hosts are associated with costly behavior toward T. gondii's definitive hosts; however, this effect has not been documented in any of the parasite's diverse wild hosts during naturally occurring interactions with felines. Here, three decades of field observations reveal that T. gondii-infected hyena cubs approach lions more closely than uninfected peers and have higher rates of lion mortality. We discuss these results in light of 1) the possibility that hyena boldness represents an extended phenotype of the parasite, and 2) alternative scenarios in which T. gondii has not undergone selection to manipulate behavior in host hyenas. Both cases remain plausible and have important ramifications for T. gondii's impacts on host behavior and fitness in the wild.
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Affiliation(s)
- Eben Gering
- Michigan State University, Department of Integrative Biology and Program in Ecology, Evolution and Behavior, East Lansing, MI, USA
- Nova Southeastern University, Department of Biological Sciences, Halmos College of Natural Sciences and Oceanography, Fort Lauderdale, FL, USA
| | - Zachary M Laubach
- Michigan State University, Department of Integrative Biology and Program in Ecology, Evolution and Behavior, East Lansing, MI, USA.
- University of Colorado Boulder, Department of Ecology and Evolutionary Biology, Boulder, CO, USA.
- Mara Hyena Project, Narok County, Kenya.
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO, USA.
| | - Patty Sue D Weber
- Michigan State University, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, East Lansing, MI, USA
| | - Gisela Soboll Hussey
- Michigan State University, Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, East Lansing, MI, USA
| | - Kenna D S Lehmann
- Michigan State University, Department of Integrative Biology and Program in Ecology, Evolution and Behavior, East Lansing, MI, USA
- Mara Hyena Project, Narok County, Kenya
| | - Tracy M Montgomery
- Michigan State University, Department of Integrative Biology and Program in Ecology, Evolution and Behavior, East Lansing, MI, USA
- Mara Hyena Project, Narok County, Kenya
- Max Planck Institute of Animal Behavior, Department for the Ecology of Animal Societies, Konstanz, Germany
| | - Julie W Turner
- Michigan State University, Department of Integrative Biology and Program in Ecology, Evolution and Behavior, East Lansing, MI, USA
- Mara Hyena Project, Narok County, Kenya
- Memorial University of Newfoundland, Department of Biology, St. John's, NL, Canada
| | - Wei Perng
- LEAD Center & University of Colorado, School of Public Health, Aurora, CO, United States
| | | | - Kay E Holekamp
- Michigan State University, Department of Integrative Biology and Program in Ecology, Evolution and Behavior, East Lansing, MI, USA
- Mara Hyena Project, Narok County, Kenya
| | - Thomas Getty
- Michigan State University, Department of Integrative Biology and Program in Ecology, Evolution and Behavior, East Lansing, MI, USA
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13
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Zhu S, Shapiro K, VanWormer E. Dynamics and epidemiology of Toxoplasma gondii oocyst shedding in domestic and wild felids. Transbound Emerg Dis 2021; 69:2412-2423. [PMID: 34153160 DOI: 10.1111/tbed.14197] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 06/18/2021] [Indexed: 11/30/2022]
Abstract
Oocyst shedding in domestic and wild felids is a critical yet understudied topic in Toxoplasma gondii ecology and epidemiology that shapes human and animal disease burden. We synthesized published literature dating from the discovery of felids as the definitive hosts of T. gondii in the 1960s through March 2021 to examine shedding prevalence, oocyst genotypes, and risk factors for shedding. Oocyst shedding prevalence in many geographic regions exceeded the commonly accepted 1% reported for domestic cats; crude prevalence from cross-sectional field studies of domestic cat shedding ranged from 0% in Australia to 18.8% in Africa, with greater variation in reports of oocyst shedding in free-ranging, wild felids. Shedding in wild felid species has primarily been described in captive animals, with attempted detection of oocyst shedding reported in at least 31 species. Differences in lifestyle and diet play an important role in explaining shedding variation between free-ranging unowned domestic cats, owned domestic cats and wild felids. Additional risk factors for shedding include the route of infection, diet, age and immune status of the host. It is widely reported that cats only shed oocysts after initial infection with T. gondii, but experimental studies have shown that repeat oocyst shedding can occur. Factors associated with repeat shedding are common amongst free-ranging felids (domestic and wild), which are more likely to eat infected prey, be exposed to diverse T. gondii genotypes, and have coinfections with other parasites. Repeat shedding events could play a significant yet currently ignored role in shaping environmental oocyst loading with implications for human and animal exposure. Oocyst presence in the environment is closely linked to climate variables such as temperature and precipitation, so in quantifying risk of exposure, it is important to consider the burden of T. gondii oocysts that can accumulate over time in diverse environmental matrices and sites, as well as the spatial heterogeneity of free-ranging cat populations. Key directions for future research include investigating oocyst shedding in under-sampled regions, genotyping of oocysts detected in faeces and longitudinal studies of oocyst shedding in free-ranging felids.
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Affiliation(s)
- Sophie Zhu
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
| | - Karen Shapiro
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
| | - Elizabeth VanWormer
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA.,School of Natural Resources, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
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14
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Viscardi M, Santoro M, Cozzolino L, Borriello G, Fusco G. A type II variant of Toxoplasma gondii infects the Eurasian otter (Lutra lutra) in southern Italy. Transbound Emerg Dis 2021; 69:874-880. [PMID: 33527733 DOI: 10.1111/tbed.14012] [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: 11/04/2020] [Revised: 01/24/2021] [Accepted: 01/26/2021] [Indexed: 11/26/2022]
Abstract
Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is a widespread zoonosis capable to affect a wide range of warm-blooded vertebrates. In the past two decades, T. gondii emerged as a significant aquatic pathogen with some pathogenic atypical genotypes isolated and characterized from stranded marine mammals. In contrast, no information is available for mammals in freshwater environment. Although otters are considered highly susceptible to T. gondii infection, to date molecular evidence of T. gondii in Eurasian otter (Lutra lutra) does not exist. We report the first molecular evidence of T. gondii in a free-ranging Eurasian otter from southern Italy and characterized the present strain as a genotype type II variant, with all loci type II except PK1 (locus sequence corresponding to type II variant B), B1 (locus sequence corresponding to type II/X A) and C29-2 (locus with SNPs). Our results indicate circulation of a type II variant in freshwater environment which suggests potential risk of transmission to animals and humans. The finding of a potential pathogenic strain is of great concern for future conservation programmes of the critically endangered Eurasian otter in southern Italy.
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Affiliation(s)
- Maurizio Viscardi
- Department of Animal Health, Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici, Italy
| | - Mario Santoro
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Loredana Cozzolino
- Department of Animal Health, Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici, Italy
| | - Giorgia Borriello
- Department of Animal Health, Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici, Italy
| | - Giovanna Fusco
- Department of Animal Health, Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici, Italy
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15
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Tomasina R, Francia ME. The Structural and Molecular Underpinnings of Gametogenesis in Toxoplasma gondii. Front Cell Infect Microbiol 2020; 10:608291. [PMID: 33365279 PMCID: PMC7750520 DOI: 10.3389/fcimb.2020.608291] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 11/04/2020] [Indexed: 01/18/2023] Open
Abstract
Toxoplasma gondii is a widely prevalent protozoan parasite member of the phylum Apicomplexa. It causes disease in humans with clinical outcomes ranging from an asymptomatic manifestation to eye disease to reproductive failure and neurological symptoms. In farm animals, and particularly in sheep, toxoplasmosis costs the industry millions by profoundly affecting their reproductive potential. As do all the parasites in the phylum, T. gondii parasites go through sexual and asexual replication in the context of an heteroxenic life cycle involving members of the Felidae family and any warm-blooded vertebrate as definitive and intermediate hosts, respectively. During sexual replication, merozoites differentiate into female and male gametes; their combination gives rise to a zygotes which evolve into sporozoites that encyst and are shed in cat's feces as environmentally resistant oocysts. During zygote formation T. gondii parasites are diploid providing the parasite with a window of opportunity for genetic admixture making this a key step in the generation of genetic diversity. In addition, oocyst formation and shedding are central to dissemination and environmental contamination with infectious parasite forms. In this minireview we summarize the current state of the art on the process of gametogenesis. We discuss the unique structures of macro and microgametes, an insight acquired through classical techniques, as well as the more recently attained molecular understanding of the routes leading up to these life forms by in vitro and in vivo systems. We pose a number of unanswered questions and discuss these in the context of the latest findings on molecular cues mediating stage switching, and the implication for the field of newly available in vitro tools.
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Affiliation(s)
- Ramiro Tomasina
- Laboratory of Apicomplexan Biology, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - María E Francia
- Laboratory of Apicomplexan Biology, Institut Pasteur de Montevideo, Montevideo, Uruguay.,Department of Parasitology and Mycology, School of Medicine, Universidad de la Republica, Montevideo, Uruguay
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16
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Badillo Flores EY, Torres Tobón MG, Aguilar Cabrera CG, Ramírez-Bravo OE, Callejas ER. Gastrointestinal Parasites in the Neotropical Otter (Lontra longicaudis annectens) in Central Mexico. WEST N AM NATURALIST 2020. [DOI: 10.3398/064.080.0412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Erika Y. Badillo Flores
- Unidad Académica de Ciencias Biológicas, Universidad Autónoma de Guerrero, Av. Javier Méndez Aponte Núm. 1 Col. Servidor Agrario C.P. 39070, Chilpancingo, Guerrero, México
| | - Marcos G. Torres Tobón
- Facultad de Medicina, Benemérita Universidad Autónoma de Puebla, 13 Sur #2702, Colonia Volcanes, C.P. 72410, Puebla, Puebla
| | - C. Gustavo Aguilar Cabrera
- Facultad de Ciencias Biológicas, Benemérita Universidad Autónoma de Puebla, 13 Sur #2702, Colonia Volcanes, C.P. 72410, Puebla, Puebla
| | - O. Eric Ramírez-Bravo
- Departmento de Investigación en Biodiversidad, Alimentación y Cambio Climático, Benemérita Universidad Autónoma de Puebla, Puebla, Puebla, México, 14 Sur 6301. CU. C.P. 72570. Col. San Manuel. Puebla, Puebla, Mexico
| | - Eva Romero Callejas
- Laboratorio de Diagnóstico Parasitológico. Facultad de Medicina Veterinaria y Zootecnia. Universidad Nacional Autónoma de México, México D.F., México
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17
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Dubey JP, Murata FHA, Cerqueira-Cézar CK, Kwok OCH, Grigg ME. Recent epidemiologic and clinical importance of Toxoplasma gondii infections in marine mammals: 2009-2020. Vet Parasitol 2020; 288:109296. [PMID: 33271425 DOI: 10.1016/j.vetpar.2020.109296] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 10/23/2020] [Accepted: 10/24/2020] [Indexed: 12/14/2022]
Abstract
Toxoplasma gondii infections are common in humans and animals worldwide. T. gondii causes mortality in several species of marine mammals, including threatened Southern sea otters (Enhydra lutris) and endangered Hawaiian monk seals (Monachus schauinslandi). Marine mammals are now considered sentinels for environmental exposure to protozoan agents contaminating marine waters, including T. gondii oocysts. Marine mammals also serve as food for humans and can result in foodborne T. gondii infections in humans. The present review summarizes worldwide information on the prevalence of clinical and subclinical infections, epidemiology, and genetic diversity of T. gondii infecting marine mammals in the past decade. The role of genetic types of T. gondii and clinical disease is discussed.
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Affiliation(s)
- Jitender P Dubey
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD 20705-2350, USA.
| | - Fernando H A Murata
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD 20705-2350, USA
| | - Camila K Cerqueira-Cézar
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD 20705-2350, USA
| | - Oliver C H Kwok
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, MD 20705-2350, USA
| | - Michael E Grigg
- Molecular Parasitology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20895, USA
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18
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Orally Bioavailable Endochin-Like Quinolone Carbonate Ester Prodrug Reduces Toxoplasma gondii Brain Cysts. Antimicrob Agents Chemother 2020; 64:AAC.00535-20. [PMID: 32540978 DOI: 10.1128/aac.00535-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 06/03/2020] [Indexed: 11/20/2022] Open
Abstract
Toxoplasmosis is a potentially fatal infection for immunocompromised people and the developing fetus. Current medicines for toxoplasmosis have high rates of adverse effects that interfere with therapeutic and prophylactic regimens. Endochin-like quinolones (ELQs) are potent inhibitors of Toxoplasma gondii proliferation in vitro and in animal models of acute and latent infection. ELQ-316, in particular, was found to be effective orally against acute toxoplasmosis in mice and highly selective for T. gondii cytochrome b over human cytochrome b Despite its oral efficacy, the high crystallinity of ELQ-316 limits oral absorption, plasma concentrations, and therapeutic potential. A carbonate ester prodrug of ELQ-316, ELQ-334, was created to decrease crystallinity and increase oral bioavailability, which resulted in a 6-fold increase in both the maximum plasma concentration (C max) and the area under the curve (AUC) of ELQ-316. The increased bioavailability of ELQ-316, when administered as ELQ-334, resulted in efficacy against acute toxoplasmosis greater than that of an equivalent dose of ELQ-316 and had efficacy against latent toxoplasmosis similar to that of ELQ-316 administered intraperitoneally. Treatment with carbonate ester prodrugs is a successful strategy to overcome the limited oral bioavailability of ELQs for the treatment of toxoplasmosis.
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19
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Toxoplasma gondii Recombinant Antigens in the Serodiagnosis of Toxoplasmosis in Domestic and Farm Animals. Animals (Basel) 2020; 10:ani10081245. [PMID: 32707821 PMCID: PMC7459674 DOI: 10.3390/ani10081245] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/15/2020] [Accepted: 07/20/2020] [Indexed: 12/22/2022] Open
Abstract
Simple Summary The very common parasite infections in animals are caused by members of Apicomplexa, including Toxoplasma gondii, Neospora sp., and Sarcocystis sp. These parasites pose serious veterinary problems. For example, the development of unambiguous diagnostic algorithms and determining the correct diagnosis are hindered by the similar antigenic structure of these parasites, as well as the multitude of similar disease symptoms presented in an infected animal. The intracellular parasite, T. gondii, infects a wide range of warm-blooded animals, including humans. This parasite is widespread among different animal populations, contributes to the loss of reproductive and malformations in young individuals, and can become a serious economic concern for farmers. Additionally, the consumption of undercooked or raw meat and the consumption of improperly processed milk product derived from farm animals are the main parasite transmission routes in humans. This work reviews potential improvements to diagnostic techniques that use recombinant antigens for serodiagnosis of toxoplasmosis in various species of animals. Abstract Toxoplasmosis is caused by an intracellular protozoan, Toxoplasma gondii, and is a parasitic disease that occurs in all warm-blooded animals, including humans. Toxoplasmosis is one of the most common parasitic diseases of animals and results in reproductive losses. Toxoplasmosis in humans is usually caused by eating raw or undercooked meat or consuming dairy products containing the parasite. Diagnosis of toxoplasmosis is currently based on serological assays using native antigens to detect specific anti-T. gondii antibodies. Due to the high price, the available commercial agglutination assays are not suited to test a large number of animal serum samples. The recent development of proteomics elucidated the antigenic structure of T. gondii and enabled the development of various recombinant antigens that can be used in new, cheaper, and more effective diagnostic tools. Continuous development of scientific disciplines, such as molecular biology and genetic engineering, allows for the production of new recombinant antigens and provides the basis for new diagnostic tests for the detection of anti-T. gondii antibodies in animal serum samples.
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