Molecules to modeling: Toxoplasma gondii oocysts at the human–animal–environment interface

VanWormer, Elizabeth; Fritz, Heather M.; Shapiro, Karen; Mazet, Jonna A. K.; Conrad, Patricia A.

doi:10.1016/j.cimid.2012.10.006

Cited by 80 publications

(63 citation statements)

References 196 publications

(188 reference statements)

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“…Most of these intermediate hosts do not hunt or scavenge warm‐blooded prey, so infection by ingestion of bradyzoite cysts in the tissues of other intermediate hosts (e.g., migrating birds) is unlikely. A growing body of evidence suggests that T. gondii infections in marine intermediate hosts are likely attributable to ingestion of oocysts that were transported to the ocean by overland watersheds (Conrad et al ., ; Miller et al ., ; VanWormer et al ., ).…”

Section: Introductionmentioning

confidence: 97%

Concentration and retention of Toxoplasma gondii oocysts by marine snails demonstrate a novel mechanism for transmission of terrestrial zoonotic pathogens in coastal ecosystems

Krusor

Smith

Tinker

et al. 2015

Environmental Microbiology

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The parasite Toxoplasma gondii is an environmentally persistent pathogen that can cause fatal disease in humans, terrestrial warm-blooded animals and aquatic mammals. Although an association between T. gondii exposure and prey specialization on marine snails was identified in threatened California sea otters, the ability of kelp-dwelling snails to transmit terrestrially derived pathogens has not been previously investigated. The objective of this study was to measure concentration and retention of T. gondii by marine snails in laboratory aquaria, and to test for natural T. gondii contamination in field-collected snails. Following exposure to T. gondii-containing seawater, oocysts were detected by microscopy in snail faeces and tissues for 10 and 3 days respectively. Nested polymerase chain reaction was also applied as a method for confirming putative T. gondii oocysts detected in snail faeces and tissues by microscopy. Toxoplasma gondii was not detected in field-collected snails. Results suggest that turban snails are competent transport hosts for T. gondii. By concentrating oocysts in faecal pellets, snails may facilitate entry of T. gondii into the nearshore marine food web. This novel mechanism also represents a general pathway by which marine transmission of terrestrially derived microorganisms can be mediated via pathogen concentration and retention by benthic invertebrates.

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Section: Introductionmentioning

confidence: 97%

Concentration and retention of Toxoplasma gondii oocysts by marine snails demonstrate a novel mechanism for transmission of terrestrial zoonotic pathogens in coastal ecosystems

Krusor

Smith

Tinker

et al. 2015

Environmental Microbiology

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“…gondii complex life cycle that are key to infection in an intermediate host: sporozoites within sporulated oocysts that are ingested from the environment, rapidly growing tachyzoites that disseminate the infection within a host, and the slowly dividing bradyzoites in tissue cysts that produce the chronic infection [4]. Although tissue cysts can initiate a new infection in a naïve host, epidemiological reports and risk-factor assessments indicate that oocysts are a major source of transmission and are a major public health concern given their prevalence and persistence as environmental contaminants [5–8]. …”

Section: Introductionmentioning

confidence: 99%

An in vitro model of intestinal infection reveals a developmentally regulated transcriptome of Toxoplasma sporozoites and a NF-κB-like signature in infected host cells

et al. 2017

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Toxoplasmosis is a zoonotic infection affecting approximately 30% of the world’s human population. After sexual reproduction in the definitive feline host, Toxoplasma oocysts, each containing 8 sporozoites, are shed into the environment where they can go on to infect humans and other warm-blooded intermediate hosts. Here, we use an in vitro model to assess host transcriptomic changes that occur in the earliest stages of such infections. We show that infection of rat intestinal epithelial cells with mature sporozoites primarily results in higher expression of genes associated with Tumor Necrosis Factor alpha (TNFα) signaling via NF-κB. Furthermore, we find that, consistent with their biology, these mature, invaded sporozoites display a transcriptome intermediate between the previously reported day 10 oocysts and that of their tachyzoite counterparts. Thus, this study uncovers novel host and pathogen factors that may be critical for the establishment of a successful intracellular niche following sporozoite-initiated infection.

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“…Anthropogenic activities and demographic changes are modifying the dispersion and emergence patterns of pathogens (Jones et al 2008). Additionally, human coastal development can change populations of felids, increase T. gondii oocysts in water runoff, and disrupt disease dynamics, increasing the importance of a holistic approach to the study of this parasite (VanWormer et al 2013a). Understanding the epidemiology of T. gondii in an ecosystem context is critical to human and animal health as this parasite represents a good example of the complexity in multi-host pathogen transmission.…”

Section: Discussionmentioning

confidence: 99%

Tracking Toxoplasma gondii in freshwater ecosystems: interaction with the invasive American mink (Neovison vison) in Spain

et al. 2018

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Water-borne transmission may play an important role in the epidemiology of Toxoplasma gondii. Mammals closely related to freshwater ecosystems, such as the American mink (Neovison vison), are potentially valuable sentinels for T. gondii. To assess the importance of freshwater ecosystems in T. gondii epidemiology, sera of 678 American minks collected during the 2010 to 2015 Spanish national eradication campaigns were tested for the presence of T. gondii antibodies using the modified agglutination test (MAT, cut-off 1:25). A high prevalence of samples, 78.8% (CI: 75.5-81.8), were seropositive. In addition, a specific real-time PCR was performed in 120 brain samples and the parasite DNA was detected in 9.2% (CI: 5.2-15.7). Significant differences in seroprevalence were detected among bioregions, with the highest levels detected in coastal areas, and by age. The higher seroprevalence observed in older animals (80.0% adults versus 68.7% juveniles) confirms the importance of the horizontal transmission. These results indicate a widespread presence of T. gondii oocysts in freshwater ecosystems from Spain and further support the importance of water-borne transmission in the epidemiology of T. gondii.

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Molecules to modeling: Toxoplasma gondii oocysts at the human–animal–environment interface

Cited by 80 publications

References 196 publications

Concentration and retention of Toxoplasma gondii oocysts by marine snails demonstrate a novel mechanism for transmission of terrestrial zoonotic pathogens in coastal ecosystems

Concentration and retention of Toxoplasma gondii oocysts by marine snails demonstrate a novel mechanism for transmission of terrestrial zoonotic pathogens in coastal ecosystems

An in vitro model of intestinal infection reveals a developmentally regulated transcriptome of Toxoplasma sporozoites and a NF-κB-like signature in infected host cells

Tracking Toxoplasma gondii in freshwater ecosystems: interaction with the invasive American mink (Neovison vison) in Spain

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