Kinetics of the local and systemic antibody response to primary and secondary infection with S48 Toxoplasma gondii in sheep

Wastling, Jonathan M.; Harkins, David; Maley, S.W.; Innes, Elisabeth A.; Panton, W.R.M.; Thomson, Kathryn; Buxton, D.

doi:10.1016/s0021-9975(05)80089-1

Cited by 22 publications

(12 citation statements)

References 19 publications

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“…This ELISA used a water-soluble antigen fraction of T. gondii tachyzoites of the S48 strain [25]. Data was expressed as percentage positivity in comparison to a standard, high titre, positive control serum obtained from an experimentally infected animal.…”

Section: Methodsmentioning

confidence: 99%

Increased Toxoplasma gondii positivity relative to age in 125 Scottish sheep flocks; evidence of frequent acquired infection

Katzer

Brülisauer

Collantes-Fernández

et al. 2011

Vet Res

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Toxoplasma gondii seroprevalence was determined in 3333 sheep sera from 125 distinct sheep flocks in Scotland, with the majority of flocks being represented by 27 samples, which were collected between July 2006 and August 2008. The selected farms give a representative sample of 14 400 sheep holdings identified in the Scottish Government census data from 2004. Overall T. gondii seroprevalence, at individual sheep level, was determined to be 56.6%; each flock tested, had at least a single positive animal and in four flocks all ewes tested positive. The seroprevalence of sheep increased from 37.7% in one year old stock to 73.8% in ewes that were older than six years, showing that acquired infections during the life of the animals is frequent and that environmental contamination by T. gondii oocysts must be significant. The median within-flock seroprevalence varied significantly across Scotland, with the lowest seroprevalence of 42.3% in the South and the highest seroprevalence of 69.2% in the far North of Scotland and the Scottish Islands, while the central part of Scotland had a seroprevalence of 57.7%. This distribution disequilibrium may be due to the spread and survival of oocysts on pasture and lambing areas. A questionnaire accompanying sampling of flocks identified farms that used Toxovax®, a commercial vaccine that protects sheep from abortion due to T. gondii infection. Only 24.7% of farmers used the vaccine and the vaccine did not significantly affect the within flock seroprevalence for T. gondii. The implications for food safety and human infection are discussed.

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Section: Methodsmentioning

confidence: 99%

Increased Toxoplasma gondii positivity relative to age in 125 Scottish sheep flocks; evidence of frequent acquired infection

Katzer

Brülisauer

Collantes-Fernández

et al. 2011

Vet Res

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“…Com relação aos títulos de anticorpos anti-T. gondii encontrados, os fatores que podem influenciar a variação dos mesmos podem estar relacionados com características de patogenicidade e virulência do agente ou da dose infectante, assim como observado por Larsson (1989). Nos títulos de anticorpos obtidos em cada localidade, os maiores títulos (2048 e 4096) foram observados em três distritos -Arroio Grande, Pains e Santa Flora, podendo assim, sugerir uma infecção aguda ou reinfecção por T. gondii, demonstrando que os títulos podem estar relacionados com o tempo de infecção (Wastling et al 1995, Dzitko et al 2006.…”

Section: Discussionunclassified

Prevalência de anticorpos e fatores de risco associados à infecção por Toxoplasma gondii em galinhas domésticas da zona rural de Santa Maria, Rio Grande do Sul

et al. 2018

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RESUMO: Toxoplasma gondii é um protozoário apicomplexa que infecta animais de sangue quente, podendo ser considerado um dos principais parasitas capazes de infectar os seres humanos. Galinhas domésticas podem ser facilmente infectadas por protozoários, uma vez que estas podem ingerir oocistos encontrados no solo, sendo consideradas boas indicadoras de contaminação ambiental por T. gondii. O objetivo deste estudo foi determinar a presença de anticorpos anti-T. gondii em galinhas domésticas criadas extensivamente e avaliar os fatores de risco associados ao protozoário, na zona rural de Santa Maria, RS, Brasil. No período de março de 2013 a fevereiro 2014 foram coletadas 597 amostras de sangue de galinhas domésticas em 74 propriedades, oriundas de nove estratos que representam cada distrito da zona rural. Para avaliar os fatores de risco, nessas propriedades foi aplicado um questionário epidemiológico aos moradores. As amostras de soro foram testadas por imunofluorescência indireta, e 49,2% (294/597) foram positivas para anticorpos anti-T. gondii, com títulos variando de 16 a 4096. Das 74 propriedades analisadas, em 63 (85,1%) houve relatos que os gatos têm acesso ao deposito de alimentos, com associação significativa quando associado à presença de galinhas positivas (p=0,04) e o OR de 4,07. A variável “abate de animais” (aves e bovinos), em 51 (68,9%) das propriedades foi relatado o abate de bovinos e aves na propriedade, com valor de p significativo (p=0,05). A maioria das propriedades 59 (79,7%) foi relatada a presença de gatos domésticos, o que poderia estar associada com a alta soroprevalência encontrada em galinhas e a taxa de contaminação ambiental. A elevada prevalência de anticorpos encontrada neste estudo, além da alta frequência de propriedades com casos positivos, sugere uma grande contaminação ambiental nos distritos pesquisados, sendo assim um risco potencial para a saúde humana e animal.

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“…However, they do not always indicate whether the infection is acute or chronic (Hill and Dubey 2002), although they do provide valuable epidemiological information (Seefeldt et al 1989;Wastling et al 1995;Werre et al 2002). Recent work investigated the maturation of specific antibodies to determine when infection was acquired.…”

Section: Introductionmentioning

confidence: 99%

Immunodiagnosis of primary Toxoplasma gondii infection in sheep by the use of a P30 IgG avidity ELISA

Sager

Gloor

Tenter

et al. 2003

Parasitology Research

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Toxoplasma gondii is a protozoan parasite with a worldwide distribution. In both sheep and humans, if the parasite is encountered during pregnancy, fetal infection and abortion can occur. Therefore, Toxoplasma infection in sheep has a major economic impact upon sheep farming. Clinically, there is a need to distinguish recent (acute) infections from longstanding (chronic) infections. However, current serological techniques, such as detection of anti-T. gondii IgG, cannot discriminate between acute and chronic infections. Increasing immunoglobulin avidity is a good determining factor of how recent an infection is. In this study, we describe the application and validation of a T. gondii IgG avidity ELISA, based on the use of an affinity-purified, native T. gondii P30 antigen. The assay was used to examine sera from eight sheep experimentally infected with T. gondii and found that all seroconverted within 21 days post-infection (p.i.), beginning with avidities that were initially low but that increased over time, with all sheep reaching high IgG avidity within 10 weeks p.i. In addition, sera from clinically healthy but T. gondii-seropositive lambs and ewes and seropositive ewes with a history of abortion were also subjected to a preliminary serological investigation. High IgG avidities were found in 80% of the seropositive lambs, in 90% of the clinically healthy ewes and in 97% of the ewes with abortion problems. These findings indicate that the animals had most likely contacted the parasite a longer time ago.

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Kinetics of the local and systemic antibody response to primary and secondary infection with S48 Toxoplasma gondii in sheep

Cited by 22 publications

References 19 publications

Increased Toxoplasma gondii positivity relative to age in 125 Scottish sheep flocks; evidence of frequent acquired infection

Increased Toxoplasma gondii positivity relative to age in 125 Scottish sheep flocks; evidence of frequent acquired infection

Prevalência de anticorpos e fatores de risco associados à infecção por Toxoplasma gondii em galinhas domésticas da zona rural de Santa Maria, Rio Grande do Sul

Immunodiagnosis of primary Toxoplasma gondii infection in sheep by the use of a P30 IgG avidity ELISA

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