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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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Methods to assess the effect of meat processing on viability of Toxoplasma gondii: towards replacement of mouse bioassay by in vitro testing. Int J Parasitol 2020; 50:357-369. [DOI: 10.1016/j.ijpara.2020.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 04/13/2020] [Accepted: 04/17/2020] [Indexed: 12/11/2022]
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Waap H, Cardoso R, Leitão A, Nunes T, Vilares A, Gargaté MJ, Meireles J, Cortes H, Ângelo H. In vitro isolation and seroprevalence of Toxoplasma gondii in stray cats and pigeons in Lisbon, Portugal. Vet Parasitol 2012; 187:542-7. [DOI: 10.1016/j.vetpar.2012.01.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 01/13/2012] [Accepted: 01/17/2012] [Indexed: 11/24/2022]
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Miller D, Davis J, Rosa R, Diaz M, Perez E. Utility of tissue culture for detection of Toxoplasma gondii in vitreous humor of patients diagnosed with toxoplasmic retinochoroiditis. J Clin Microbiol 2000; 38:3840-2. [PMID: 11015415 PMCID: PMC87488 DOI: 10.1128/jcm.38.10.3840-3842.2000] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/1999] [Accepted: 05/08/2000] [Indexed: 11/20/2022] Open
Abstract
Laboratory recovery and confirmation of the etiologic agent in necrotizing retinochoroiditis are problematic. Tissue culture and intraocular antibody titers were compared as adjuncts to clinical diagnosis for toxoplasmic retinochoroiditis: the correlations were 91 and 67%, respectively. Isolation of Toxoplasma gondii may establish a definitive diagnosis in patients with toxoplasmic retinochoroiditis.
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Affiliation(s)
- D Miller
- Ocular Microbiology Department, Bascom Palmer Eye Institute, Anne Bates Leach Eye Hospital, University of Miami School of Medicine, Miami, Florida 33136, USA.
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Chaves-Borges FA, Souza MA, Silva DA, Kasper LH, Mineo JR. Detection of Toxoplasma gondii soluble antigen, SAG-1(p30), antibody and immune complex in the cerebrospinal fluid of HIV positive or negative individuals. Rev Inst Med Trop Sao Paulo 1999; 41:329-38. [PMID: 10671285 DOI: 10.1590/s0036-46651999000600001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Active infection by T. gondii was evaluated by immunoassay for soluble SAG-1 (p30), the major surface antigen from T. gondii, specific antibodies and immune complexes in human cerebrospinal fluid (CSF) samples. A total of 263 samples of CSF were collected from hospitalized patients presenting neurological disorders and analyzed for antibodies to HIV. Patients were divided into two groups: HIV positive (n = 96) or HIV negative (n =167). The results of the assays showed that 45% of all samples were positive for soluble SAG-1. Toxoplasma Ag/Ab immune complexes were detected in 19% of the CSF samples and 62% were positive for T. gondii- specific IgG. A combination of these assays in the presence of clinical findings consistent with active Toxoplasma infection may predict the presence of toxoplasmic encephalitis. Moreover, detection of soluble SAG-1 in the CSF of these individuals appears consistent with active infection.
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Affiliation(s)
- F A Chaves-Borges
- Laboratory of Immunology, Department of Pathology, Universidade Federal de Uberlândia, Uberlândia, MG, 38400-902, Brazil
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Contini C, Fainardi E, Cultrera R, Canipari R, Peyron F, Delia S, Paolino E, Granieri E. Advanced laboratory techniques for diagnosing Toxoplasma gondii encephalitis in AIDS patients: significance of intrathecal production and comparison with PCR and ECL-western blotting. J Neuroimmunol 1998; 92:29-37. [PMID: 9916877 DOI: 10.1016/s0165-5728(98)00160-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The polymerase chain reaction (PCR) for detection of cerebral spinal fluid (CSF) Toxoplasma gondii DNA was combined with the study of intrathecal antibody synthesis by antibody specific index calculation (ASI) and the detection of specific oligoclonal IgG bands (OCB) by affinity mediated immunoblotting (AMI) in 11 AIDS patients with T. gondii encephalitis (TE) and in 20 control patients with or without neurological disorders. Enhanced chemiluminescence (ECL) western-blot technique was employed to evaluate the antigenic specificity of CSF-IgG towards individual T. gondii antigens. PCR was positive in all TE patients which displayed brain-derived or blood-derived specific OCB, even when comparative ASI failed. Four TE patients had a unique anti-T. gondii OCB restricted to the CSF and a strong antibody response toward the 29 kDa band by ECL western blot. This response could be an important marker to discriminate TE from other opportunistic central nervous system (CNS) infections in the course of AIDS.
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Affiliation(s)
- C Contini
- Department of Clinical and Experimental Medicine, University of Ferrara, Italy.
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Raffi F, Aboulker JP, Michelet C, Reliquet V, Pelloux H, Huart A, Poizot-Martin I, Morlat P, Dupas B, Mussini JM, Leport C. A prospective study of criteria for the diagnosis of toxoplasmic encephalitis in 186 AIDS patients. The BIOTOXO Study Group. AIDS 1997; 11:177-84. [PMID: 9030364 DOI: 10.1097/00002030-199702000-00007] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To define the factors associated with diagnosis of toxoplasmic encephalitis (TE) in AIDS patients; and to establish a rational procedure for the clinician faced with a decision concerning empiric antitoxoplasma therapy. DESIGN A 15-month prospective multicentre cohort study in France. METHODS One hundred and eighty-six consecutive HIV-positive inpatients undergoing empiric antitoxoplasma therapy for a first episode of presumed TE were monitored. The clinician's initial estimation of the probability of response to antitoxoplasma therapy was recorded. In addition, a validation committee classified cases as TE or non-TE. RESULTS Among the 186 patients, the following variables were significantly more frequent in TE (n = 113) than non-TE (n = 73) patients: fever (59% versus 40%). headache (55% versus 33%), seizures (22% versus 11%), suggestive lesions on the brain scan (98% versus 76%), positive Toxoplasma serology (97% versus 71%). Median CD4+ lymphocyte count was significantly higher in TE than in non-TE (27 x 10(6)/l versus 11 x 10(6)/l). The rate of TE in patients on systemic antiprotozoal prophylaxis at entry was 43% as compared with 75% in patients without previous prophylaxis. Pre-therapy estimation of response to empiric therapy was highly correlated with final diagnosis. Multivariate logistic regression analysis showed that the following variables contributed independently to the diagnosis of TE: clinician's estimation of response to treatment at entry > 75%; absence of systemic antiprotozoal prophylaxis; seizures; headache; suggestive lesions on CT or MRI brain scan; and positive Toxoplasma serology. CONCLUSIONS A linear logistic model is proposed which uses significant variables, which are readily available. This model gives good accuracy to classify suspected cases of TE.
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Affiliation(s)
- F Raffi
- Department of Infectious Diseases, University Hospital, Nantes, France
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