Toxoplasma gondii and HIV: a never-ending story

Nissapatorn, Veeranoot

doi:10.1016/s2352-3018(17)30003-6

Cited by 20 publications

(15 citation statements)

References 10 publications

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“…The coccidian parasite T. gondii undergoes asexual replication in its intermediate hosts in two distinct stages: the fast‐growing tachyzoites that are responsible for severe symptomatic disease in susceptible hosts [26–28], and the slow‐growing encysted bradyzoites that persist for the lifetime of their host [29]. Tachyzoites and bradyzoites differ not only in their growth rate, but also in their metabolism [30–32].…”

Section: Heme Demand In Protozoan Parasitesmentioning

confidence: 99%

“…Cobalamin is synthesized by some bacteria and archaea, including Pseudomonas denitrificans and Salmonella typhimurium via an aerobic or anaerobic synthesis pathway. responsible for severe symptomatic disease in susceptible hosts [26][27][28], and the slow-growing encysted bradyzoites that persist for the lifetime of their host [29]. Tachyzoites and bradyzoites differ not only in their growth rate, but also in their metabolism [30][31][32].…”

Section: Heme Demand In Protozoan Parasitesmentioning

confidence: 99%

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Supply and demand—heme synthesis, salvage and utilization by Apicomplexa

2020

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The Apicomplexa phylum groups important human and animal pathogens that cause severe diseases, encompassing malaria, toxoplasmosis, and cryptosporidiosis. In common with most organisms, apicomplexans rely on heme as cofactor for several enzymes, including cytochromes of the electron transport chain. This heme derives from de novo synthesis and/or the development of uptake mechanisms to scavenge heme from their host. Recent studies have revealed that heme synthesis is essential for Toxoplasma gondii tachyzoites, as well as for the mosquito and liver stages of Plasmodium spp. In contrast, the erythrocytic stages of the malaria parasites rely on scavenging heme from the host red blood cell. The unusual heme synthesis pathway in Apicomplexa spans three cellular compartments and comprises enzymes of distinct ancestral origin, providing promising drug targets. Remarkably given the requirement for heme, T. gondii can tolerate the loss of several heme synthesis enzymes at a high fitness cost, while the ferrochelatase is essential for survival. These findings indicate that T. gondii is capable of salvaging heme precursors from its host. Furthermore, heme is implicated in the activation of the key antimalarial drug artemisinin. Recent findings established that a reduction in heme availability corresponds to decreased sensitivity to artemisinin in T. gondii and Plasmodium falciparum, providing insights into the possible development of combination therapies to tackle apicomplexan parasites. This review describes the microeconomics of heme in Apicomplexa, from supply, either from de novo synthesis or scavenging, to demand by metabolic pathways, including the electron transport chain.

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Section: Heme Demand In Protozoan Parasitesmentioning

confidence: 99%

Section: Heme Demand In Protozoan Parasitesmentioning

confidence: 99%

Supply and demand—heme synthesis, salvage and utilization by Apicomplexa

2020

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“…Moreover, the findings of higher IgM antibodies than IgG ones signal active transmission going on in that community. Therefore, in any case, research looking after vulnerable communities, pregnant women, and HIV/AIDS patients should take T. gondii into serious consideration in order to achieve early diagnosis and prevent the development of chronic clinical conditions [ 85 , 86 ].…”

Section: Innovative Diagnostic Approach and Vaccine Development Fomentioning

confidence: 99%

A Review on the Prevalence of Toxoplasma gondii in Humans and Animals Reported in Malaysia from 2008–2018

Wana

Moklas

Watanabe

et al. 2020

IJERPH

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Toxoplasmosis is a disease caused by the protozoan parasite Toxoplasma gondii (T. gondii). Human toxoplasmosis seroprevalence in Malaysia has increased since it was first reported in 1973 as shown in previous reviews of 1991 and 2007. However, over a decade since the last review, comprehensive data on toxoplasmosis in Malaysia is lacking. This work aimed at reviewing articles on toxoplasmosis research in Malaysia in order to identify the research gaps, create public awareness, and efforts made so far and proffer management options on the disease. The present review examines the available published research articles from 2008 to 2018 related to toxoplasmosis research conducted in Malaysia. The articles reviewed were retrieved from nine credible databases such as Web of Science, Google Scholar, ScienceDirect, PubMed, Scopus, Springer, Wiley online library, Ovid, and Cochrane using the keywords; Malaysia, toxoplasmosis, Toxoplasma gondii, toxoplasma encephalitis, seroprevalence, human immunodeficiency virus (HIV) patients, pregnant women, genotype strain, anti-toxoplasma antibodies, felines, and vaccine. The data highlighted seropositive cases from healthy community members in Pangkor Island (59.7%) and among migrant workers (57.4%) at alarming rates, as well as 42.5% in pregnant women. Data on animal seroprevalence were limited and there was no information on cats as the definitive host. Genetic characterization of Toxoplasma gondii from HIV patients; pregnant women, and domestic cats is lacking. This present review on toxoplasmosis is beneficial to researchers, health workers, animal health professionals, and policymakers. Therefore, attention is required to educate and enlighten health workers and the general public about the risk factors associated with T. gondii infection in Malaysia.

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“…Toxoplasma has been reported as the most common cause of focal brain lesions among PLHIV [9] . Reactivation remains the predominant route by which Toxoplasma infection manifests especially among those with a CD4 cell count of below 200 cells/μL, and it carries a risk of fatal outcome if untreated [8,10,11] .…”

Section: Introductionmentioning

confidence: 99%

Global status of Toxoplasma gondii infection and associated risk factors in people living with HIV

Safarpour

Çevik

Zarean

et al. 2020

Aids

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Objective: Toxoplasma infection remains as the most common cause of focal brain lesions among people living with HIV (PLHIV) despite the decline in opportunistic infections with the introduction of antiretroviral treatment. This study was conducted to provide a summary of evidence about the seroprevalence of Toxoplasma gondii and prevalence of active T. gondii infection and associated risk factors among PLHIV. Design: PRISMA guidelines were followed. Scopus, PubMed, Science Direct, and EMBASE were searched from 1997 to July 2018. All peer-reviewed original research articles describing T. gondii infection among PLHIV with different diagnostic methods were included. Methods: Incoherence and heterogeneity between studies were quantified by I2 index and Cochran's Q test. Publication and population bias were assessed with funnel plots and Egger's regression asymmetry test. All statistical analyses were performed using StatsDirect. Results: A total of 111 studies from 37 countries assessing 66,139 blood samples were included in this study. The pooled prevalence of T. gondii infection among PLHIV was 3.24% by IgM and 26.22% by molecular methods using the random-effects model. Pooled seroprevalence of T. gondii by IgG was 44.22%. There was a relationship between Toxoplasma prevalence and gender, raw meat consumption, contact with cat and knowledge about toxoplasmosis. Conclusion: High Toxoplasma seroprevalence among PLHIV observed in this study emphasizes the need for implementing screening and prophylaxis tailored to the local context. Owing to the serious and significant clinical manifestations of the parasite in case of reactivation, early identification of seropositivity for initiating prophylaxis among those with a CD4 count of <200cells/mL is recommended.

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Toxoplasma gondii and HIV: a never-ending story

Cited by 20 publications

References 10 publications

Supply and demand—heme synthesis, salvage and utilization by Apicomplexa

Supply and demand—heme synthesis, salvage and utilization by Apicomplexa

A Review on the Prevalence of Toxoplasma gondii in Humans and Animals Reported in Malaysia from 2008–2018

Global status of Toxoplasma gondii infection and associated risk factors in people living with HIV

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