scholarly journals Toxoplasma gondii infections are associated with boldness towards lions in wild hyena hosts

2020 ◽  
Author(s):  
Eben Gering ◽  
Zachary M. Laubach ◽  
Patricia Weber ◽  
Gisela Soboll Hussey ◽  
Kenna D. S. Lehmann ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Parasite Transmission ◽  
Field Observations ◽  
Extended Phenotype ◽  
Intermediate Hosts ◽  
Behavioral Interactions ◽  
Behavioral Manipulation ◽  
Wild Host ◽  
Show Evidence ◽  
Globally Distributed

AbstractToxoplasma gondii is widely reported to manipulate the behavior of its non-definitive hosts in ways that promote lethal interactions with the parasite’s definitive feline hosts. Nonetheless, there is a lack of data on the association between T. gondii infection and costly behavioral interactions with felids in nature. Here, we report that three decades of field observations reveal T. gondii infected hyena cubs approach lions more closely than uninfected peers and have higher rates of lion mortality. Our findings support the hypothesis that T. gondii’s manipulation of host boldness is an extended phenotype that promotes parasite transmission from intermediate hosts to feline predators. While upregulating hyena boldness toward lions might achieve this, it may also reflect a collateral influence of manipulative traits that evolved in other hosts (e.g., rodents). In either case, our findings corroborate the potential impacts of a globally distributed and generalist parasite (T. gondii) on fitness-related interaction with felids in a wild host.One Sentence SummaryWild hyenas infected with the parasite T. gondii show evidence of costly behavioral manipulation when interacting with lions.

scholarly journals Toxoplasma gondii infections are associated with costly boldness toward felids in a wild host

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eben Gering ◽  
Zachary M. Laubach ◽  
Patty Sue D. Weber ◽  
Gisela Soboll Hussey ◽  
Kenna D. S. Lehmann ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Field Observations ◽  
Extended Phenotype ◽  
Trophic Transmission ◽  
Host Behavior ◽  
Naturally Occurring ◽  
Wild Host ◽  
In The Wild ◽  
Alternative Scenarios ◽  
Wild Hosts

AbstractToxoplasma gondii is hypothesized to manipulate the behavior of warm-blooded hosts to promote trophic transmission into the parasite’s definitive feline hosts. A key prediction of this hypothesis is that T. gondii infections of non-feline hosts are associated with costly behavior toward T. gondii’s definitive hosts; however, this effect has not been documented in any of the parasite’s diverse wild hosts during naturally occurring interactions with felines. Here, three decades of field observations reveal that T. gondii-infected hyena cubs approach lions more closely than uninfected peers and have higher rates of lion mortality. We discuss these results in light of 1) the possibility that hyena boldness represents an extended phenotype of the parasite, and 2) alternative scenarios in which T. gondii has not undergone selection to manipulate behavior in host hyenas. Both cases remain plausible and have important ramifications for T. gondii’s impacts on host behavior and fitness in the wild.

Insights into the molecular basis of host behaviour manipulation by Toxoplasma gondii infection

2017 ◽  
Vol 1 (6) ◽  
pp. 563-572 ◽  
Author(s):  
Pierre-Mehdi Hammoudi ◽  
Dominique Soldati-Favre
Keyword(s):  
Toxoplasma Gondii ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Brain Regions ◽  
Intermediate Hosts ◽  
Toxoplasma Gondii Infection ◽  
Host Parasite ◽  
Host Behaviour ◽  
The Brain ◽  
Brain Homeostasis

Typically illustrating the ‘manipulation hypothesis’, Toxoplasma gondii is widely known to trigger sustainable behavioural changes during chronic infection of intermediate hosts to enhance transmission to its feline definitive hosts, ensuring survival and dissemination. During the chronic stage of infection in rodents, a variety of neurological dysfunctions have been unravelled and correlated with the loss of cat fear, among other phenotypic impacts. However, the underlying neurological alteration(s) driving these behavioural modifications is only partially understood, which makes it difficult to draw more than a correlation between T. gondii infection and changes in brain homeostasis. Moreover, it is barely known which among the brain regions governing fear and stress responses are preferentially affected during T. gondii infection. Studies aiming at an in-depth dissection of underlying molecular mechanisms occurring at the host and parasite levels will be discussed in this review. Addressing this reminiscent topic in the light of recent technical progress and new discoveries regarding fear response, olfaction and neuromodulator mechanisms could contribute to a better understanding of this complex host–parasite interaction.

scholarly journals Molecular identification of Toxoplasma gondii in roadkill wild animals in Yucatan, Mexico

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Marco Antonio Torres-Castro ◽  
Rodrigo Adán Medina-Pinto ◽  
Henry René Noh-Pech ◽  
Fernando I. Puerto ◽  
Roger Iván Rodríguez-Vivas
Keyword(s):  
Toxoplasma Gondii ◽  
Animal Health ◽  
Negative Control ◽  
Molecular Evidence ◽  
Wild Animals ◽  
Intermediate Hosts ◽  
Nested Polymerase Chain Reaction ◽  
Muscle Sample ◽  
Wild Mammals ◽  
Lung Sample

Toxoplasma gondii is an obligate intracellular protozoan parasite, recognized as the etiologic agent of toxoplasmosis, a zoonotic endemic disease in several countries, including Mexico. In the Yucatan State of Mexico, Toxoplasma infection has a high impact in both human and domestic animal health. Wild animals can also host zoonotic pathogens such as Toxoplasma gondii. The presence of Toxoplasma gondii DNA in roadkill wild animals in Yucatan was detected using a nested Polymerase Chain Reaction. Toxoplasma gondii DNA was identified in several organs retrieved from a Yucatan squirrel (Sciurus yucatanensis), a coatimundi (Nasua narica), and a greater grison (Galictis vittata). The amplified fragments of Toxoplasma gondii DNA were purified, sequenced, and certified by BLAST analysis. Our results confirm that Toxoplasma gondii can infect wild mammals from Yucatan, which could act as intermediate hosts and contribute to the transmission of the disease to humans and domestic animals, as well as other wild animal species. We present the first molecular evidence of Toxoplasma gondii in a squirrel and a coatimundi from Yucatan, and quite possibly in a greater grison at a global level.Figure 1. Agarose gel presenting PCR amplicons (560 bp) positive to Toxoplasma gondii. 1) C+: positive control; A: Yucatan squirrel liver sample; B: great grison femoral muscle sample; C: coatimundi kidney sample; C-: negative control. 2) A: Yucatan squirrel brain sample; B: great grison lung sample; C-: negative control.

Tissue cyst tropism in Toxoplasma gondii: a comparison of tissue cyst formation in organs of cats, and rodents fed oocysts

Parasitology ◽  
1997 ◽  
Vol 115 (1) ◽  
pp. 15-20 ◽  
Author(s):  
J. P. DUBEY
Keyword(s):  
Toxoplasma Gondii ◽  
Cyst Formation ◽  
Tissue Cyst ◽  
Intermediate Hosts ◽  
Mesenteric Lymph Nodes ◽  
Marked Contrast ◽  
Mesenteric Lymph ◽  
Time Period ◽  
Rats And Mice ◽  
The Brain

The persistence of Toxoplasma gondii tissue cysts in organs of cats (definitive host) and rodents (intermediate hosts) was studied. Nine cats, 12 rats, and 12 mice were fed T. gondii oocysts and their organs were digested in pepsin and then bioassayed for bradyzoites in mice. Of 9 cats killed 37 or 51 days after feeding 102 (2 cats), 103 (3 cats) or 104 (4 cats) oocysts of the VEG strain, tissue cysts were found in each cat; in the tongue of 9, in the heart of 5, in the brain of 4, and in the eyes of 1 cat. The dose had no effect on the distribution of tissue cysts in cats. Twelve rats were each fed 105 oocysts of the VEG strain of T. gondii and killed 21, 29, 64 or 237 days later. At each time-period, 11 tissues of 3 rats were pooled and bioassayed in mice. Tissue cysts were found in the brain, skeletal muscle, heart and kidneys of rats at each killing time; in the lungs, intestines, and mesenteric lymph nodes in 3 of 4 instances; in the tongue, liver, and eyes in 2 instances and in the spleen in 1 instance. Also, using the same procedures and sampling the same 11 tissues as used for rats, tissue cysts were seen in all organs except in the tongue and liver of 3 mice killed on day 82 after feeding the VEG strain. In 9 mice (3 with each strain) fed oocysts of the ME-49, GT-1, or P89 T. gondii strain and killed 62–130 days later, tissue cysts were found consistently only in the brain. Thus, in rats and mice, most tissue cysts were found in the brain and rarely in the tongue. This was in marked contrast to the distribution of tissue cysts in cats.

scholarly journals Multiscale approach reveals that Cloudina aggregates are detritus and not in situ reef constructions

2018 ◽  
Vol 115 (11) ◽  
pp. E2519-E2527 ◽  
Author(s):  
Akshay Mehra ◽  
Adam Maloof
Keyword(s):  
Imaging System ◽  
Imaging Techniques ◽  
Minor Role ◽  
Multiscale Approach ◽  
Field Observations ◽  
3D Reconstructions ◽  
Physical Separation ◽  
A Minor ◽  
Globally Distributed

The earliest metazoans capable of biomineralization appeared during the late Ediacaran Period (635–541 Ma) in strata associated with shallow water microbial reefs. It has been suggested that some Ediacaran microbial reefs were dominated (and possibly built) by an abundant and globally distributed tubular organism known as Cloudina. If true, this interpretation implies that metazoan framework reef building—a complex behavior that is responsible for some of the largest bioconstructions and most diverse environments in modern oceans—emerged much earlier than previously thought. Here, we present 3D reconstructions of Cloudina populations, produced using an automated serial grinding and imaging system coupled with a recently developed neural network image classifier. Our reconstructions show that Cloudina aggregates are composed of transported remains while detailed field observations demonstrate that the studied reef outcrops contain only detrital Cloudina buildups, suggesting that Cloudina played a minor role in Ediacaran reef systems. These techniques have wide applicability to problems that require 3D reconstructions where physical separation is impossible and a lack of density contrast precludes tomographic imaging techniques.

scholarly journals Toxoplasma gondii antibodies and related risk factors in mammals at Sorocaba zoo, São Paulo, BrazilToxoplasma gondii antibodies and related risk factors in mammals at Sorocaba zoo, São Paulo, Brazil

2017 ◽  
Vol 38 (4Supl1) ◽  
pp. 2845
Author(s):  
Renata Bezerra Marujo ◽  
Helio Langoni ◽  
Leila Sabrina Ullmann ◽  
Maysa Pellizzaro ◽  
Ramiro Das Neves Dias Neto ◽  
...  
Keyword(s):  
Risk Factors ◽  
Toxoplasma Gondii ◽  
Feeding Habits ◽  
Univariate Analysis ◽  
Multivariate Logistic Regression Analysis ◽  
Sao Paulo ◽  
São Paulo ◽  
Intermediate Hosts ◽  
Serum Samples ◽  
Related Risk

Toxoplasmosis is a parasitic zoonosis with worldwide distribution and different wild species either are involved in maintenance of the pathogen in the environment as definitive or intermediate hosts serving as font of feeding or prey to definitive hosts. The present study aimed to investigate Toxoplasma gondii antibodies and the risk factors relating to infection in mammals at Sorocaba Zoo, state of São Paulo, Brazil. Serum samples collected from 153 animals were analyzed using the modified agglutination test (MAT; cutoff ? 25). Seropositivity was found in 62 animals (40.5%; 95% CI: 33.1-48.5%), with different titers. Significant differences were observed in relation to the ages of the animals, origin, presence of free-ranging animals in the enclosure and feeding habits, through univariate analysis (p ? 0.05). Multivariate logistic regression analysis showed that only age (p = 0.03) had significance for the study. Adult animals were 3.5 more likely to become infected than were young ones. In relation to feeding habits, herbivores (80%) and carnivores (46.5%) were the animals most affected. These results highlight the presence of T. gondii in animals at Brazilian zoos, and suggest that continuous transmission is occurring at zoos.

scholarly journals Variation in Angiostrongylus cantonensis infection in definitive and intermediate hosts in Hawaii, a global hotspot of rat lungworm disease

Parasitology ◽  
2020 ◽  
pp. 1-10
Author(s):  
Chris N. Niebuhr ◽  
Shane R. Siers ◽  
Israel L. Leinbach ◽  
Lisa M. Kaluna ◽  
Susan I. Jarvi
Keyword(s):  
Disease Surveillance ◽  
Strong Predictor ◽  
Management Strategies ◽  
Angiostrongylus Cantonensis ◽  
Infection Prevalence ◽  
Intermediate Hosts ◽  
Related Factors ◽  
Crucial Component ◽  
Wild Host ◽  
Rat Lungworm

Abstract Angiostrongylus cantonensis (rat lungworm) is a tropical and subtropical parasitic nematode, with infections in humans causing angiostrongyliasis (rat lungworm disease), characterized by eosinophilic meningitis. Hawaii has been identified as a global hotspot of infection, with recent reports of high infection rates in humans, as well as rat definitive and snail intermediate hosts. This study investigated variation in A. cantonensis infection, both prevalence and intensity, in wild populations of two species of rats (Rattus exulans and R. rattus) and one species of snail (Parmarion martensi). An overall infection prevalence of 86.2% was observed in P. martensi and 63.8% in rats, with R. exulans (77.4%) greater than R. rattus (47.6%). We found infections to vary with environmental and host-related factors. Body mass was a strong predictor of infection in all three species, with different patterns seen between sexes and species of rats. Infection prevalence and intensity for R. exulans were high in May 2018 and again in February 2019, but generally lower and more variable during the intervening months. Information on sources of variability of infection in wild host populations will be a crucial component in predicting the effectiveness of future disease surveillance or targeted management strategies.

Evidence for genetic diversity of Toxoplasma gondii in selected intermediate hosts in Serbia

2014 ◽  
Vol 37 (3) ◽  
pp. 173-179 ◽  
Author(s):  
Marija Marković ◽  
Vladimir Ivović ◽  
Tijana Štajner ◽  
Vitomir Djokić ◽  
Ivana Klun ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Toxoplasma Gondii ◽  
Intermediate Hosts

scholarly journals Prevalence of Toxoplasma gondii, Neospora caninum, and Sarcocystis Species DNA in the Heart and Breast Muscles of Rock Pigeons (Columbia livia)

2018 ◽  
Vol 2018 ◽  
pp. 1-4 ◽  
Author(s):  
Muhammad Mudasser Nazir ◽  
Muhammad Mazhar Ayaz ◽  
Atif Nisar Ahmed ◽  
Azhar Maqbool ◽  
Kamran Ashraf ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Environmental Contamination ◽  
Breast Tissue ◽  
Neospora Caninum ◽  
Breast Muscle ◽  
Sarcocystis Species ◽  
Protozoan Parasites ◽  
Intermediate Hosts ◽  
Columbia Livia ◽  
Animal Sciences

Little is known about the prevalence of protozoan parasites in the muscles of rock pigeons (Columbia livia). The muscles from 54 (heart from 45 and breast from 54) rock pigeons were examined for DNA of Toxoplasma gondii, Neospora caninum, and Sarcocystis species using PCR. Twenty-four were female and 30 were males. The birds were part of flocks of pigeons housed at the tombs of saints in Lahore, Pakistan. Birds that died or were euthanized due to poor health were submitted for necropsy at the Department of Parasitology, University of Veterinary and Animal Sciences, Lahore, Pakistan, where DNA isolations and PCR were conducted. Nineteen (35.1%) of the birds were positive for T. gondii DNA. Seven males and 12 females were positive. Breast tissue was always infected in T. gondii positive birds, while the heart was infected in 13 (28.8%) of breast positive birds. Five (9.2%) of the pigeons, 2 males and 3 females, were positive for N. caninum. The distribution of N. caninum DNA was more variable in the muscles of pigeons than T. gondii and was found only in the heart of 1 (female), heart and breast muscle of 2 (male), and only the breast muscle of 2 birds (female). One of the 54 rock pigeons (female) was positive for both T. gondii (heart and breast) and N. caninum (heart only). Two of the positive Neospora caninum amplicons were sequenced and had 97% nucleotide identity with N. caninum isolates. Sarcocystis DNA was not found in any bird. The prevalence of T. gondii in rock pigeons and their predation by cats suggest that they may play an unrecognized role in maintaining environmental contamination with T. gondii oocysts by cats. Our study indicates that rock pigeons are intermediate hosts of N. caninum and this information will aid in understanding the epidemiology of N. caninum.

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