scholarly journals Exposure of pelagic seabirds to Toxoplasma gondii in the Western Indian Ocean points to an open sea dispersal of this terrestrial parasite

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255664
Author(s):  
Marie-Lazarine Poulle ◽  
Matthieu Le Corre ◽  
Matthieu Bastien ◽  
Elsa Gedda ◽  
Chris Feare ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Indian Ocean ◽  
Contaminated Soils ◽  
Protozoan Parasite ◽  
Western Indian Ocean ◽  
Intermediate Hosts ◽  
Modified Agglutination Test ◽  
Open Sea ◽  
Initial Deposition ◽  
Paratenic Hosts

Toxoplasma gondii is a protozoan parasite that uses felids as definitive hosts and warm-blooded animals as intermediate hosts. While the dispersal of T. gondii infectious oocysts from land to coastal waters has been well documented, transmission routes to pelagic species remain puzzling. We used the modified agglutination test (MAT titre ≥ 10) to detect antibodies against T. gondii in sera collected from 1014 pelagic seabirds belonging to 10 species. Sampling was carried out on eight islands of the Western Indian Ocean: Reunion and Juan de Nova (colonized by cats), Cousin, Cousine, Aride, Bird, Europa and Tromelin islands (cat-free). Antibodies against T. gondii were found in all islands and all species but the great frigatebird. The overall seroprevalence was 16.8% [95% CI: 14.5%-19.1%] but significantly varied according to species, islands and age-classes. The low antibody levels (MAT titres = 10 or 25) detected in one shearwater and three red-footed booby chicks most likely resulted from maternal antibody transfer. In adults, exposure to soils contaminated by locally deposited oocysts may explain the detection of antibodies in both wedge-tailed shearwaters on Reunion Island and sooty terns on Juan de Nova. However, 144 adults breeding on cat-free islands also tested positive. In the Seychelles, there was a significant decrease in T. gondii prevalence associated with greater distances to cat populations for species that sometimes rest on the shore, i.e. terns and noddies. This suggests that oocysts carried by marine currents could be deposited on shore tens of kilometres from their initial deposition point and that the number of deposited oocysts decreases with distance from the nearest cat population. The consumption of fishes from the families Mullidae, Carangidae, Clupeidae and Engraulidae, previously described as T. gondii oocyst-carriers (i.e. paratenic hosts), could also explain the exposure of terns, noddies, boobies and tropicbirds to T. gondii. Our detection of antibodies against T. gondii in seabirds that fish in the high sea, have no contact with locally contaminated soils but frequent the shores and/or consume paratenic hosts supports the hypothesis of an open-sea dispersal of T. gondii oocysts by oceanic currents and/or fish.

Regional seroprevalence of Toxoplasma gondii antibodies in feral and stray cats (Felis catus) from Tasmania

2014 ◽  
Vol 62 (4) ◽  
pp. 272 ◽  
Author(s):  
Bronwyn A. Fancourt ◽  
Robert B. Jackson
Keyword(s):  
Toxoplasma Gondii ◽  
Wildlife Conservation ◽  
Protozoan Parasite ◽  
Felis Catus ◽  
Rapid Decline ◽  
Tasmanian Devil ◽  
Igg Antibodies ◽  
Feral Cat ◽  
Modified Agglutination Test ◽  
Stray Cats

Toxoplasma gondii is a cosmopolitan protozoan parasite of felids that also has significant implications for the health of wildlife, livestock and humans worldwide. In Australia, feral, stray and domestic cats (Felis catus) are the most important definitive host of T. gondii as they are the only species that can excrete the environmentally resistant oocysts that provide a major source of infection for mammals and birds. In Tasmania, the rapid decline of the Tasmanian devil (Sarcophilus harrisii) may allow an increase in feral cat abundance, thereby increasing the risk of T. gondii infection to a range of susceptible wildlife species. At present, there is scant information on the prevalence of T. gondii infection in feral cat populations across Tasmania. We tested feral cats from 13 regions across Tasmania for the presence of T. gondii–specific IgG antibodies using a modified agglutination test. Results were combined with serosurveys from three previous studies to enable a comparison of seroprevalence among 14 regions across Tasmania. We found that 84.2% (224 of 266) of cats tested positive for T. gondii IgG antibodies. This is among the highest rates of prevalence recorded from Australia, and significantly higher than for most other countries. Adult cats had higher seroprevalence than kittens but there was no difference between sexes. In Tasmania, seroprevalence was high in 12 of 14 regions (range: 79.3–100.0%), with only two regions (Tasman Island and Southern Tasmania) recording significantly lower seroprevalence (≤50%). This suggests a high risk of infection across Tasmania, and has significant implications for wildlife conservation should feral cat abundance increase with the ongoing declines in Tasmanian devils.

Bulinus on Aldabra and the subfamily Bulininae in the Indian Ocean area

1971 ◽  
Vol 260 (836) ◽  
pp. 299-313 ◽  
Keyword(s):  
Indian Ocean ◽  
Western Indian Ocean ◽  
Starch Gel Electrophoresis ◽  
Intermediate Hosts ◽  
Tropical Regions ◽  
Ocean Area ◽  
Freshwater Molluscs ◽  
Mitotic Metaphase Chromosome ◽  
Morphological Criteria ◽  
The Indian Ocean

The molluscan family Planorbidae is widely distributed throughout the temperate and tropical regions of the world. The subfamily Bulininae includes two genera only, Bulinus which is confined to the Ethiopian zoogeographical region, the Mediterranean area, the Middle East and some islands in the Western Indian Ocean, and Indoplanorbis which is common throughout India and Southeast Asia and also occurs on Socotra. These snails have been the subject of particularly intense study because of their importance as intermediate hosts for blood-flukes of the genus Schistosoma parasitic in man and domestic animals. The presence of a species of Bulinus on Aldabra is interesting because of the relative rarity of freshwater molluscs on atolls and also because it has served as a focus for drawing together the results of recent investigations into the distribution, relationships and intermediate host capacity of bulinids in the Indian Ocean area. This area has presented a number of problems in the interpretation of patterns of schistosomiasis transmission and most of these problems stem from misunderstandings about the taxonomy of the host snails and their parasites. Many of the misunderstandings have arisen from the paucity and unreliable nature of morphological criteria for taxonomic studies in basommatophoran snails and these have now been supplemented by cytogenetic, biochemical and immunological information. The methods used include paper chromatography of bodysurface mucus (Wright 1964), electrophoresis of egg proteins on cellulose acetate (Wright & Ross 1965, 1966), starch-gel electrophoresis of digestive-gland enzymes (Wright, File & Ross 1966; Wright & File 1968), Ouchterlony plate gel diffusion and agar-gel immuno-electrophoresis of egg proteins using antisera prepared in rabbits, and colcimid blocking of mitotic metaphase chromosome figures in developing embryos.

scholarly journals Seroepidemiology of Toxoplasma gondii in domestic cattle, sheep, goats and pigs from São Tomé and Príncipe

2020 ◽  
Vol 29 (1) ◽  
Author(s):  
Daniela Cruz Pereira ◽  
Jitender Pradash Dubey ◽  
Alfredo da Mata ◽  
Helda Neto ◽  
Luís Cardoso ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Geographical Area ◽  
Central Area ◽  
Local Environment ◽  
Intermediate Hosts ◽  
Adult Age ◽  
Source Of Infection ◽  
Modified Agglutination Test ◽  
Sao Tome And Principe ◽  
Zoonotic Parasite

Abstract Despite the global importance of the zoonotic parasite Toxoplasma gondii, little is known regarding its infection in the Democratic Republic of São Tomé and Príncipe (DRSTP). This is the first report of antibodies to T. gondii in cattle, sheep, goats and pigs from the DRSTP. Antibodies were assessed by the modified agglutination test (MAT), with a cut-off titer of 100 for cattle and 20 for sheep, goats and pigs. The present study revealed an overall seroprevalence of 55.8%; 27.1% in 48 cattle, 68.4% in 98 sheep, 70.1% in 97 goats and 43.7% in 103 pigs. The south geographical area for cattle, the central area for sheep, and adult age and living in the central region for goats were found to be risk factors for seropositivity to T. gondii. These results support the scenario of a considerable presence of sporulated oocysts as well as of infected intermediate hosts in the local environment. Consumption of raw or undercooked meat should be considered as an important potential source of infection for animals and humans in the DRSTP.

scholarly journals Frequency of Toxoplasma gondii antibodies in tufted capuchin monkeys (Cebus apella nigritus) from an ecological station in the State of São Paulo, Brazil

2013 ◽  
Vol 33 (2) ◽  
pp. 251-253 ◽  
Author(s):  
Rodrigo Costa da Silva ◽  
Gustavo Puglia Machado ◽  
Tatiane Morosini de Andrade Cruvinel ◽  
Ciro Alexandre Cruvinel ◽  
Helio Langoni
Keyword(s):  
Toxoplasma Gondii ◽  
Cebus Apella ◽  
Sao Paulo ◽  
Capuchin Monkeys ◽  
São Paulo ◽  
Intermediate Hosts ◽  
Serum Samples ◽  
Obligate Intracellular ◽  
Modified Agglutination Test ◽  
Tufted Capuchin Monkeys

Toxoplasmosis is a worldwide zoonosis caused by Toxoplasma gondii, an obligate intracellular parasite protozoan. A large percentage of animals presents specific antibodies caused by a previous exposition, resulting in a chronic infection. Felides are the definitive hosts and the other warm-blooded animals, including primates, are the intermediate hosts. This study was aimed to determine the prevalence of T. gondii infection in free-living tufted capuchin monkeys (Cebus apella nigritus) from an ecological station located on Mata de Santa Teresa, Ribeirão Preto, SP, Brazil. T. gondii antibodies were analyzed by modified agglutination test (MAT) in serum samples of 36 tufted capuchin monkeys, considering eight as cut-off titer. From the studied animals, 3/36 (8.33%; CI95% 3.0-21.9%) presented T. gondii antibodies, all with titer 32. No significative difference was observed relating to the sex (1/3 male and 2/3 female), and to the age (1/3 young and 2/3 adult) (P>0.05). Thus, these results demonstrate the presence of T. gondii antibodies in primates from São Paulo state.

scholarly journals Inactivation of Toxoplasma gondii Bradyzoites after Salt Exposure during Preparation of Dry-Cured Hams

2020 ◽  
Vol 83 (6) ◽  
pp. 1038-1042 ◽  
Author(s):  
JORRELL FREDERICKS ◽  
DIANE S. HAWKINS-COOPER ◽  
DOLORES E. HILL ◽  
JOHN B. LUCHANSKY ◽  
ANNA C. S. PORTO-FETT ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Foodborne Pathogens ◽  
Trichinella Spiralis ◽  
Protozoan Parasite ◽  
Mouse Bioassay ◽  
Modified Agglutination Test ◽  
Frequent Use ◽  
Inspection Service ◽  
Step Over ◽  
The U.S

ABSTRACT Foodborne pathogens continue to pose a public health risk and can cause serious illness and significant outbreaks of disease in consumers. Toxoplasmosis is a zoonotic disease that occurs worldwide and is caused by the protozoan parasite, Toxoplasma gondii. The consumption of raw or undercooked infected meat, including pork, that contains infectious stages of T. gondii has been regarded as a major route of T. gondii transmission to humans. Given the occasional presence of T. gondii in pork meat, the frequent use of pork for products not intended to be cooked, such as dry-cured ham, presents a potential risk for its transmission to consumers. In this study, we investigated the viability of T. gondii in dry-cured whole hams processed using methods that were previously required for treatment of hams to inactivate Trichinella spiralis in the U.S. Code of Federal Regulations (9 CFR 318.10) and are now described in guidance documents from the U.S. Food Safety and Inspection Service. Infected pork hams were salted and cured for 33 days at 3°C and 85% ± 5% relative humidity (RH) and then were dried for up to 12 months at 12°C and 67.5% ± 2.5% RH. Inactivation of T. gondii was assessed in mouse bioassays and, serologically, by the modified agglutination test (MAT). Results showed that T. gondii bradyzoites were inactivated during the salting and curing step (33 days); no viable T. gondii was detected in the mouse bioassay and no evidence of serological conversion was detected by MAT in any of the mice inoculated with any of the samples tested during the drying step over the 12 months of the experiment. These results demonstrated that the approved protocols for production of dry-cured hams validated herein can inactivate T. gondii and lower the risk to consumers of this product. HIGHLIGHTS

scholarly journals A single-parasite transcriptional atlas of Toxoplasma Gondii reveals novel control of antigen expression

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Yuan Xue ◽  
Terence C Theisen ◽  
Suchita Rastogi ◽  
Abel Ferrel ◽  
Stephen R Quake ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Toxoplasma Gondii ◽  
Developmental Process ◽  
Protozoan Parasite ◽  
Antigen Expression ◽  
Asexual Development ◽  
Intermediate Hosts ◽  
Related Sequence ◽  
Gene Sets ◽  
Hidden States

Toxoplasma gondii, a protozoan parasite, undergoes a complex and poorly understood developmental process that is critical for establishing a chronic infection in its intermediate hosts. Here, we applied single-cell RNA-sequencing (scRNA-seq) on >5,400 Toxoplasma in both tachyzoite and bradyzoite stages using three widely studied strains to construct a comprehensive atlas of cell-cycle and asexual development, revealing hidden states and transcriptional factors associated with each developmental stage. Analysis of SAG1-related sequence (SRS) antigenic repertoire reveals a highly heterogeneous, sporadic expression pattern unexplained by measurement noise, cell cycle, or asexual development. Furthermore, we identified AP2IX-1 as a transcription factor that controls the switching from the ubiquitous SAG1 to rare surface antigens not previously observed in tachyzoites. In addition, comparative analysis between Toxoplasma and Plasmodium scRNA-seq results reveals concerted expression of gene sets, despite fundamental differences in cell division. Lastly, we built an interactive data-browser for visualization of our atlas resource.

scholarly journals The Structural and Molecular Underpinnings of Gametogenesis in Toxoplasma gondii

2020 ◽  
Vol 10 ◽  
Author(s):  
Ramiro Tomasina ◽  
María E. Francia
Keyword(s):  
Toxoplasma Gondii ◽  
Reproductive Potential ◽  
Protozoan Parasite ◽  
Life Forms ◽  
Farm Animals ◽  
Genetic Admixture ◽  
Intermediate Hosts ◽  
Male Gametes

Toxoplasma gondii is a widely prevalent protozoan parasite member of the phylum Apicomplexa. It causes disease in humans with clinical outcomes ranging from an asymptomatic manifestation to eye disease to reproductive failure and neurological symptoms. In farm animals, and particularly in sheep, toxoplasmosis costs the industry millions by profoundly affecting their reproductive potential. As do all the parasites in the phylum, T. gondii parasites go through sexual and asexual replication in the context of an heteroxenic life cycle involving members of the Felidae family and any warm-blooded vertebrate as definitive and intermediate hosts, respectively. During sexual replication, merozoites differentiate into female and male gametes; their combination gives rise to a zygotes which evolve into sporozoites that encyst and are shed in cat’s feces as environmentally resistant oocysts. During zygote formation T. gondii parasites are diploid providing the parasite with a window of opportunity for genetic admixture making this a key step in the generation of genetic diversity. In addition, oocyst formation and shedding are central to dissemination and environmental contamination with infectious parasite forms. In this minireview we summarize the current state of the art on the process of gametogenesis. We discuss the unique structures of macro and microgametes, an insight acquired through classical techniques, as well as the more recently attained molecular understanding of the routes leading up to these life forms by in vitro and in vivo systems. We pose a number of unanswered questions and discuss these in the context of the latest findings on molecular cues mediating stage switching, and the implication for the field of newly available in vitro tools.

scholarly journals Behavioral biology of Toxoplasma gondii infection

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Wen Han Tong ◽  
Chris Pavey ◽  
Ryan O’Handley ◽  
Ajai Vyas
Keyword(s):  
Life Cycle ◽  
Toxoplasma Gondii ◽  
Protozoan Parasite ◽  
Research Area ◽  
Complex Life Cycle ◽  
Future Research ◽  
Intermediate Hosts ◽  
Laboratory Rodents ◽  
Toxoplasma Gondii Infection ◽  
Host Parasite

AbstractToxoplasma gondii is a protozoan parasite with a complex life cycle and a cosmopolitan host range. The asexual part of its life cycle can be perpetually sustained in a variety of intermediate hosts through a combination of carnivory and vertical transmission. However, T. gondii produces gametes only in felids after the predation of infected intermediate hosts. The parasite changes the behavior of its intermediate hosts by reducing their innate fear to cat odors and thereby plausibly increasing the probability that the definitive host will devour the infected host. Here, we provide a short description of such parasitic behavioral manipulation in laboratory rodents infected with T. gondii, along with a bird’s eye view of underpinning biological changes in the host. We also summarize critical gaps and opportunities for future research in this exciting research area with broad implications in the transdisciplinary study of host–parasite relationships.

scholarly journals Prevalence and risk factors for exposure to Toxoplasma gondii in slaughterhouse workers in western Kenya

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Elizabeth Anne Jessie Cook ◽  
Nduhiu Gitahi ◽  
William Anson de Glanville ◽  
Lian F. Thomas ◽  
Samuel Kariuki ◽  
...  
Keyword(s):  
Risk Factors ◽  
Toxoplasma Gondii ◽  
General Population ◽  
Protozoan Parasite ◽  
Raw Milk ◽  
High Risk Group ◽  
Vulnerable Groups ◽  
Intermediate Hosts ◽  
Animal Blood ◽  
Raw Meat

Abstract Background Toxoplasma gondii is a zoonotic protozoan parasite infecting warm-blooded animals. Infection in people can occur through ingestion of oocysts passed in the faeces of the definitive hosts; ingestion of bradyzoites in the tissue of infected intermediate hosts; or exposure to tachyzoites in raw milk and eggs. Slaughterhouse workers are considered a high-risk group for T. gondii exposure because of their contact with raw meat, although a positive relationship between handling raw meat and T. gondii seropositivity has not been demonstrated in all studies. This study aimed to determine the seroprevalence of antibodies to T. gondii in slaughterhouse workers in Kenya and identify risk factors associated with seropositivity. Methods A survey of slaughterhouse workers was conducted in 142 slaughter facilities in the study area. Information regarding demographics, contact with livestock, meat consumption, and practices in the slaughterhouse was collected using structured questionnaires. Commercial ELISAs were used to detect IgM and IgG antibodies against T. gondii and a multi-level logistic regression model was used to identify potential risk factors for seropositivity in slaughterhouse workers. Results The apparent prevalence of antibodies to T. gondii was 84.0% (95% Confidence Interval (CI) 81.2–86.5%) for IgG and 2.2% (95% CI 1.3–3.5%) for IgM antibodies. All IgM positive individuals were IgG positive. Risk factors for exposure to T. gondii were: increasing age (Odds Ratio (OR) 1.03; 95% CI 1.01–1.05); owning poultry (OR 2.00; 95% CI 1.11–3.62); and consuming animal blood (OR 1.92; 95% CI 1.21–3.03). Conclusions The seroprevalence of antibodies to T. gondii was very high in this population and considerably higher than published values in the general population. Risk factors included age, owning poultry and drinking animal blood which were consistent with previous reports but none were specifically associated with working in the slaughterhouse. In this instance slaughterhouse workers may represent a useful sentinel for the general population where the level of exposure is also likely to be high and may signify an unidentified public health risk to vulnerable groups such as pregnant women. A detailed understanding of the epidemiology of infection is required, which should include an assessment of incidence, mortality, and burden since T. gondii infection is likely to have life-long sequelae.

Toxoplasma gondii seroprevalence in endangered bridled nailtail wallabies and co-occurring species

2020 ◽  
Vol 42 (2) ◽  
pp. 167
Author(s):  
Alexandra K. Ross ◽  
Janelle Lowry ◽  
Andrew Elphinstone ◽  
Jasmin C. Lawes
Keyword(s):  
Toxoplasma Gondii ◽  
Canis Lupus ◽  
Oryctolagus Cuniculus ◽  
Agglutination Test ◽  
Unexpected Result ◽  
Captive Population ◽  
Wild Populations ◽  
Intermediate Hosts ◽  
Modified Agglutination Test ◽  
Invasive Species Control

The parasite Toxoplasma gondii can infect any warm-blooded species; however, seroprevalence in most species remains largely unknown. In this study we examined the presence of T. gondii antibodies in captured individuals in the two remaining wild populations and one captive population of endangered bridled nailtail wallabies (Onychogalea fraenata). Samples from cats (Felis catus), rabbits (Oryctolagus cuniculus) and dogs (Canis lupus) were also taken opportunistically during invasive species control at the two wild populations. Seventy-one wallabies, sixteen cats, four rabbits, and two dogs’ blood samples were tested for T. gondii using a modified agglutination test. Half of the tested feral cats (n = 8) were seropositive and all intermediate hosts were seronegative for T. gondii antibodies. This unexpected result suggests a loss of infected individuals before capture and testing, or parasite infectivity being suppressed by Queensland’s hot, dry climate.

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