The Apicomplexan Parasite Toxoplasma gondii

Delgado, Inês; Zúquete, Sara; Santos, Dulce; Basto, Afonso P.; Leitão, Alexandre; Nolasco, Sofia

doi:10.3390/encyclopedia2010012

Cited by 22 publications

(15 citation statements)

References 200 publications

(334 reference statements)

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“…In the different age groups of cows showed that the prevalence of T. gondii DNA considerably increases with the age of the cow. The present research was coherent with the reported prevalence in cows from different countries such as 20% from Mohmand agency, Pakistan (Shah et al, 2013), 13.3% by ELISA from Sudan (Elfahal et al, 2013), 15.91% from Iran (Delgado et al, 2022), and all these support the present study. While the reported prevalence of T. gondii in cattle from Serbia the estimated prevalence of T. gondii was observed 76.3% in cattle (Klun et al, 2006), and from Brazil, 71% prevalence of T. gondii was reported in cattle (Santos et al, 2009) which was extremely higher than the present study.…”

Section: Discussionsupporting

confidence: 92%

Toxoplasma gondii in lactating animals: potential risk to milk consuming population in Khyber Pakhtunkhwa

et al. 2023

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Toxoplasma gondii is an intracellular zoonotic protozoan parasite usually infects human and animal worldwide. This study aimed to analyze the sero-prevalence of T. gondii in blood of lactating animals and human living in close proximity and also to detect Toxoplasma DNA in unpasteurized milk of the studied animals. A total of 233 blood and milk samples were collected from lactating animals, and 735 blood samples were taken from humans in District Upper Dir, Khyber Pakhtunkhwa, Pakistan. The blood samples were analyzed through ELISA while the milk samples were analyzed by PCR for the presence of T. gondii DNA. A standard questionnaire was introduced to collect the data from the participants. In animals, the reported sero-prevalence was 32.18% for IgM, 17.16% for IgG, and 6.4% for both IgM and IgG. The reported positivity for T. gondii DNA in milk was 14.44%, 34.8%, 20%, and 26% in sheep, goats, cows, and buffaloes, respectively. In the human blood samples, 9.8% were found positive for IgM and 11.2% for IgG while none of the samples was found positive for both IgM and IgG. Overall sero-prevalence reported in females was significantly higher than the male (p<0.05) poor hygiene condition (p < 0.0001) were the significant risk factors associated with T. gondii infections in animals. In conclusion, T. gondii infection is prevalent in lactating animals and humans using their raw milk in the study area. It is suggested that raw milk should be considered as a vehicle for the transmission of T. gondii to humans. Proper pasteurization of milk is very useful in limiting the transmission of infection. Awareness and control programs should be implemented to prevent the infection.

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Section: Discussionsupporting

confidence: 92%

Toxoplasma gondii in lactating animals: potential risk to milk consuming population in Khyber Pakhtunkhwa

et al. 2023

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“…Experimental access to these stages is paramount to study the pathogenic mechanisms and to develop urgently needed therapies and vaccines. The most widespread member of the Apicomplexa is Toxoplasma gondii , causative agent of toxoplasmosis, which has a broad host range and can infect any warm-blooded animal and humans (for review see 1 , 2 ). An estimated 25% of the world’s population is infected with the parasite, with large local variations 3 .…”

Section: Introductionmentioning

confidence: 99%

“…Parasites then differentiate into bradyzoites within tissue cysts that are found primarily in the eye, brain and muscle tissue ( Figure 1A ). In addition to this asexual replication, sexual recombination can take place in felines, the definitive hosts ( Figure 1C ) 1 . The sporozoite-containing oocysts formed during this process are shed into the environment with the feces and can withstand harsh environmental stresses such as ultraviolet irradiation, salinity, high and low temperatures, and desiccation, allowing them to remain infectious for months and even years ( Figure 1D ) 7 .…”

Section: Introductionmentioning

confidence: 99%

Advances towards the complete in vitro life cycle of Toxoplasma gondii

Warschkau¹,

Seeber²

2023

Fac Rev

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The full life cycle of Toxoplasma gondii cannot be recapitulated in vitro , and access to certain stages, such as mature tissue cysts (bradyzoites) and oocysts (sporozoites), traditionally requires animal experiments. This has greatly hindered the study of the biology of these morphologically and metabolically distinct stages, which are essential for the infection of humans and animals. However, several breakthrough advances have been made in recent years towards obtaining these life stages in vitro , such as the discovery of several molecular factors that induce differentiation and commitment to the sexual cycle, and different culture methods that use, for example, myotubes and intestinal organoids to obtain mature bradyzoites and different sexual stages of the parasite. We review these novel tools and approaches, highlight their limitations and challenges, and discuss what research questions can already be answered with these models. We finally identify future routes for recapitulating the entire sexual cycle in vitro .

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“…In humans, they contribute to a spectrum of diseases with significant mortality rates, impacting billions of people worldwide. Malaria, cryptosporidiosis, and toxoplasmosis stand out as the primary diseases caused by parasites in this phylum 1 . These parasites effectively manipulate the infected cells to create the necessary niche for establishing the infection [2][3][4][5] .…”

Section: Introductionmentioning

confidence: 99%

Host autophagy is exploited by the intracellular parasiteToxoplasma gondiito enhance amino acids levels

White,

Angara,

Dias

et al. 2023

Preprint

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Toxoplasma gondii,a widespread parasite, has the ability to infect nearly any nucleated cell in warm-blooded vertebrates. It is estimated that around 2 billion people globally have been infected by this pathogen. Although most healthy individuals can effectively control parasite replication, certain parasites may evade the immune response, establishing cysts in the brain that are refractory to the immune system and resistance to available drugs. For its chronic persistence in the brain, the parasite relies on host cells’ nutrients, particularly amino acids and lipids. Therefore, understanding how latent parasites persist in the brain is crucial for identifying potential drug targets against chronic forms. While shielded within parasitophorous vacuoles (PVs) or cysts,Toxoplasmaexploits the host endoplasmic reticulum (ER) metabolism to sustains its persistence in the brain, resulting in host neurological alterations. In this study, we demonstrate thatT. gondiidisrupts the host ER homeostasis, resulting in accumulation of unfolded protein with the host ER. The host counters this stress by initiating an autophagic pathway known as ER-phagy, which breaks down unfolded proteins into amino acids, promoting their recycling. Remarkably, the persistence of latent forms in cell culture as well as behavioral changes in mice caused by the latent infection could be successfully reversed by restricting the availability of various amino acids duringT. gondiinfection. Our findings unveil the underlying mechanisms employed byT. gondiito exploit host ER and lysosomal pathways, enhancing nutrient levels during infection. These insights provide new strategies for the treatment of toxoplasmosis.ImportanceIntracellular parasites employ several mechanisms to manipulate the cellular environment, enabling them to persist in the host.Toxoplasma gondii, a single-celled parasite, possesses the ability to infect virtually any nucleated cell of warm-blooded vertebrates, including nearly 2 billion people worldwide. Unfortunately, existing treatments and immune responses are not entirely effective in eliminating the chronic persisting forms of the parasite. This study reveals thatT. gondiiinduces the host’s autophagic pathway to boost amino acid levels in infected cells. The depletion of amino acids, in turn, influences the persistence of the parasite’s chronic forms, resulting in a reduction of neurological alterations caused by chronic infection in mice. Significantly, our investigation establishes the crucial role of host ER-phagy in the parasite’s persistence within the host during latent infection.

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The Apicomplexan Parasite Toxoplasma gondii

Cited by 22 publications

References 200 publications

Toxoplasma gondii in lactating animals: potential risk to milk consuming population in Khyber Pakhtunkhwa

Toxoplasma gondii in lactating animals: potential risk to milk consuming population in Khyber Pakhtunkhwa

Advances towards the complete in vitro life cycle of Toxoplasma gondii

Host autophagy is exploited by the intracellular parasiteToxoplasma gondiito enhance amino acids levels

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