Evaluation of propidium monoazide–based qPCR to detect viable oocysts of Toxoplasma gondii

Rousseau, Angélique; Villena, Isabelle; Dumètre, Aurélien; Escotte-Binet, Sandie; Favennec, Loïc; Dubey, J. P.; Aubert, Dominique; Carbona, Stéphanie La

doi:10.1007/s00436-019-06220-1

Cited by 21 publications

(22 citation statements)

References 56 publications

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“…However, some studies have shown that the seroprevalence is probably related to seasons [17], and the reason for this difference may be due to different environments, temperatures, and various sample qualities. Moreover, studies have shown that high temperatures have little impact on the reduction in viability of T. gondii [15].…”

Section: Discussionmentioning

confidence: 99%

Seroprevalence of Toxoplasma gondii infection in sheep in Inner Mongolia Province, China

et al. 2020

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Toxoplasma gondii is an important zoonotic parasite that can infect almost all warm-blooded animals, including humans, and infection may result in many adverse effects on animal husbandry production. Animal husbandry in Inner Mongolia is well developed, but data on T. gondii infection in sheep are lacking. In this study, we determined the seroprevalence and risk factors associated with the seroprevalence of T. gondii using an indirect enzyme-linked immunosorbent assay (ELISA) test. A total of 1853 serum samples were collected from 29 counties of Xilin Gol League (n = 624), Hohhot City (n = 225), Ordos City (n = 158), Wulanchabu City (n = 144), Bayan Nur City (n = 114) and Hulunbeir City (n = 588). The overall seroprevalence of T. gondii was 15.43%. Risk factor analysis showed that seroprevalence was higher in sheep ≥12 months of age (21.85%) than that in sheep <12 months of age (10.20%) (p < 0.01). Seroprevalence was higher in male sheep (18.76%) than females (12.80%) (p < 0.01). Barn-feeding sheep (23.13%) had higher prevalence than grazing sheep (10.94%) (p < 0.01). The seroprevalence was significantly different in different districts (p < 0.01). This study shows that sheep are exposed to T. gondii in Inner Mongolia, and provides a data reference for public health and disease control.

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Section: Discussionmentioning

confidence: 99%

Seroprevalence of Toxoplasma gondii infection in sheep in Inner Mongolia Province, China

et al. 2020

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“…Only mechanical grinding with TissueLyser (30 s) associated with Lysing Matrix E tube in IMDM growth media achieved the release of 84  14% of sporocysts. However, this percentage of released sporocysts is probably underestimated because 10%-15% of oocysts never sporulate (32). This method can be easily implemented in laboratories and can be applied to oocysts isolated from environmental or food samples as mussels.…”

Section: Discussionmentioning

confidence: 99%

“…Methods to measure the viability and infectivity of protozoa including T. gondii have been recently reviewed (31). Among molecular techniques, Propidium MonoAzide based-PCR assays appeared not relevant to measure the viability of T. gondii oocysts (32) and RNA based-methods overestimated the exposure of humans to viable oocysts because of persistence of RNA in dead parasites (33,34). Considering that all viable parasites are not necessarily infectious, i.e.…”

Section: Introductionmentioning

confidence: 99%

Toxoplasma gondii Oocyst Infectivity Assessed Using a Sporocyst-Based Cell Culture Assay Combined with Quantitative PCR for Environmental Applications

Rousseau

Escotte-Binet

Carbona

et al. 2019

Appl Environ Microbiol

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Toxoplasma gondii is a ubiquitous foodborne protozoan that can infect humans at low dose and displays different prevalences among countries in the world. Ingestion of food or water contaminated with small amounts of T. gondii oocysts may result in human infection. However, there are no regulations for monitoring oocysts in food, mainly because of a lack of standardized methods to detect them. The objectives of this study were (i) to develop a reliable method, applicable in biomonitoring, for the rapid detection of infectious oocysts by cell culture of their sporocysts combined with quantitative PCR (sporocyst-CC-qPCR) and (ii) to adapt this method to blue and zebra mussels experimentally contaminated by oocysts with the objective to use these organisms as sentinels of aquatic environments. Combining mechanical treatment and bead beating leads to the release of 84% ± 14% of free sporocysts. The sporocyst-CC-qPCR detected fewer than ten infectious oocysts in water within 4 days (1 day of contact and 3 days of cell culture) compared to detection after 4 weeks by mouse bioassay. For both mussel matrices, oocysts were prepurified using a 30% Percoll gradient and treated with sodium hypochlorite before cell culture of their sporocysts. This assay was able to detect as few as ten infective oocysts. This sporocyst-based CC-qPCR appears to be a good alternative to mouse bioassay for monitoring infectious T. gondii oocysts directly in water and also using biological sentinel mussel species. This method offers a new perspective to assess the environmental risk for human health associated with this parasite. IMPORTANCE The ubiquitous protozoan Toxoplasma gondii is the subject of renewed interest due to the spread of oocysts in water and food causing endemic and epidemic outbreaks of toxoplasmosis in humans and animals worldwide. Displaying a sensitivity close to animal models, cell culture represents a real alternative to assess the infectivity of oocysts in water and in biological sentinel mussels. This method opens interesting perspectives for evaluating human exposure to infectious T. gondii oocysts in the environment, where oocyst amounts are considered to be very small.

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“…Four cats excreted T. gondii -like oocysts; however, oocysts infectivity was not reported, and it is not clear if the kittens were tested for T. gondii antibodies before use in the experiment. Recently, methods for detection and viability measure of T. gondii oocysts were described and they could be employed in Egypt in order to determine the contamination of the environment (Rousseau et al ., 2019).…”

Section: Toxoplasmosis In Animalsmentioning

confidence: 99%

A review on toxoplasmosis in humans and animals from Egypt

Abbas

Villena

2019

Parasitology

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The present paper summarizes prevalence, epidemiology and clinical disease of natural Toxoplasma gondii infections in humans and animals from Egypt. The current situation of toxoplasmosis in Egypt is confusing. There is no central laboratory or group of researchers actively investigating toxoplasmosis in humans or animals, and no reports on the national level are available. Based on various serological tests and convenience samples, T. gondii infections appear highly prevalent in humans and animals from Egypt. Living circumstances in Egypt favour the transmission of T. gondii. Up to 95% of domestic cats, the key host of T. gondii, are infected with T. gondii; they are abundant in rural and suburban areas, spreading T. gondii oocysts. Many women have been tested in maternity clinics, most with no definitive diagnosis. Toxoplasma gondii DNA and IgM antibodies have been found in blood samples of blood donors. Clinical toxoplasmosis in humans from Egypt needs further investigations using definitive procedures. Reports on congenital toxoplasmosis are conflicting and some reports are alarming. Although there are many serological surveys for T. gondii in animals, data on clinical infections are lacking. Here, we critically review the status of toxoplasmosis in Egypt, which should be useful to biologist, public health workers, veterinarians and physicians.

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Evaluation of propidium monoazide–based qPCR to detect viable oocysts of Toxoplasma gondii

Cited by 21 publications

References 56 publications

Seroprevalence of Toxoplasma gondii infection in sheep in Inner Mongolia Province, China

Seroprevalence of Toxoplasma gondii infection in sheep in Inner Mongolia Province, China

Toxoplasma gondii Oocyst Infectivity Assessed Using a Sporocyst-Based Cell Culture Assay Combined with Quantitative PCR for Environmental Applications

A review on toxoplasmosis in humans and animals from Egypt

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