Biology and epidemiology ofToxoplasma gondiiin man and animals

2005 ◽  
Vol 6 (1) ◽  
pp. 41-61 ◽  
Author(s):  
Dolores E. Hill ◽  
Sreekumar Chirukandoth ◽  
J. P. Dubey
Keyword(s):  
Toxoplasma Gondii ◽  
Intermediate Host ◽  
Host Range ◽  
Marine Mammals ◽  
Parasitic Infections ◽  
Sea Otter ◽  
Coccidian Parasite ◽  
Wild Carnivores ◽  
Southern Sea Otter

AbstractToxoplasma gondiiis a coccidian parasite which utilizes felids as definitive hosts, and which has an unusually wide intermediate host range. The parasite was initially described by Nicolle and Manceaux in 1908 from the rodent,Ctenodactylus gundi. Infection withT. gondiiis one of the most common parasitic infections of man and other warm-blooded animals. It has been found worldwide from Alaska to Australia. Nearly one-third of humanity has been exposed to this parasite; serologic surveys indicate thatT. gondiiinfections are common in wild carnivores, including pigs, bears, felids, fox, raccoons, and skunks. Clinical and subclinical toxoplasmosis has been reported from wild cervids, ungulates, marsupials, monkeys, and marine mammals. Southern sea otter populations have been severely impacted byToxoplasmainfections.

The effect of Toxoplasma gondii and other parasites on activity levels in wild and hybrid Rattus norvegicus

Parasitology ◽  
1994 ◽  
Vol 109 (5) ◽  
pp. 583-589 ◽  
Author(s):  
J. P. Webster
Keyword(s):  
Life Cycle ◽  
Toxoplasma Gondii ◽  
Intermediate Host ◽  
Definitive Host ◽  
Rattus Norvegicus ◽  
Parasite Load ◽  
Life Cycles ◽  
Parasitic Infections ◽  
Activity Levels ◽  
In The Wild

Using both correlational and experimental evidence, the relationship between parasite load and host activity was assessed in brown rats, Rattus norvegicus. Two hypotheses were tested – (1) that parasites with indirect life-cycles, involving transmission between a prey and its predator, will alter the activity of the intermediate host so as to increase its susceptibility to predation by the definitive host and (2) that activity levels in parasitized rats would be increased rather than decreased. Four groups of rats (n = 140) were examined. One group (n = 50) were wild brown rats trapped from 3 UK farmsteads, with naturally occurring parasites. The others were purpose-bred wild/laboratory hybrid rats with experimentally induced parasitic infections of either (n = 15) adult-acquired or (n = 15) congenitally-acquired Toxoplasma gondii (an indirect life-cycle parasite), or (n = 15) Syphacia muris (a direct life-cycle parasite). Uninfected hybrid rats (n = 45), matched for sex, age and weight, served as controls. Rats were housed individually in outdoor cages, and their activities were recorded on video-tapes for 6 non-consecutive 10 h nights. Exercise wheels were also available for the hybrid rats. Out of 6 parasite species detected in the wild rats, T. gondii was the only one which required predation by a definitive host to complete its life-cycle, and was also the only parasite to be associated with higher activity levels in infected than uninfected rats. Hybrid rats infected with T. gondii were also more active than those uninfected, whereas there were no differences in activity levels between S. muris infected and uninfected rats. This study shows that the indirect life-cycle parasite T. gondii can influence the activity of its intermediate host the rat. I suggest that this may facilitate its transmission to the cat definitive host.

scholarly journals Pathomechanisms in the Kidneys in Selected Protozoan Parasitic Infections

2021 ◽  
Vol 22 (8) ◽  
pp. 4209
Author(s):  
Karolina Kot ◽  
Natalia Łanocha-Arendarczyk ◽  
Michał Ptak ◽  
Aleksandra Łanocha ◽  
Elżbieta Kalisińska ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Molecular Mechanisms ◽  
Kidney Injury ◽  
Therapeutic Interventions ◽  
Parasitic Infections ◽  
Injury Mechanisms ◽  
Kidney Involvement ◽  
Leishmania Spp ◽  
Apoptosis Process ◽  
Insight Into

Leishmaniasis, malaria, toxoplasmosis, and acanthamoebiasis are protozoan parasitic infections. They remain important contributors to the development of kidney disease, which is associated with increased patients’ morbidity and mortality. Kidney injury mechanisms are not fully understood in protozoan parasitic diseases, bringing major difficulties to specific therapeutic interventions. The aim of this review is to present the biochemical and molecular mechanisms in kidneys infected with Leishmania spp., Plasmodium spp., Toxoplasma gondii, and Acanthamoeba spp. We present available mechanisms of an immune response, oxidative stress, apoptosis process, hypoxia, biomarkers of renal injury in the serum or urine, and the histopathological changes of kidneys infected with the selected parasites. Pathomechanisms of Leishmania spp. and Plasmodium spp. infections have been deeply investigated, while Toxoplasma gondii and Acanthamoeba spp. infections in the kidneys are not well known yet. Deeper knowledge of kidney involvement in leishmaniasis and malaria by presenting their mechanisms provides insight into how to create novel and effective treatments. Additionally, the presented work shows gaps in the pathophysiology of renal toxoplasmosis and acanthamoebiasis, which need further research.

scholarly journals Epidemiological Survey of Toxoplasma gondii and Associated Risk Factors in Ruminant Species of the Khyber Pakhtunkhwa Province of Pakistan

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Abid Ali ◽  
Talha Omer ◽  
Asad Ullah ◽  
Abdul Haleem ◽  
Maryam Naseem ◽  
...  
Keyword(s):  
Risk Factors ◽  
Toxoplasma Gondii ◽  
Rural Areas ◽  
Epidemiological Survey ◽  
Parasitic Infections ◽  
Toxoplasma Infection ◽  
Ruminant Species ◽  
Starting Point ◽  
Khyber Pakhtunkhwa Province ◽  
Associated Risk Factors

Toxoplasma infection is one of the most common human parasitic diseases. During 2018-2020, in the rural areas of three districts of Pakistan, we surveyed a total of 451 animals, belonging to different asymptomatic ruminant species, to determine the prevalence of Toxoplasma gondii antibodies. We used ELISA assay as well as recorded some associated risk factors contributing to its transmission. IgM antibodies were detected in 17% and IgG in 13.4% of ruminant samples with the highest percentage, 10% for IgM and 8.6% for IgG in sheep. A strong significant association was found between antibodies and different species (IgM, χ 2 = 29 .280, P = .000 , and IgG, χ 2 = 22.580 , P = .000 ), respectively. Infection with T. gondii seems mainly associated with different geographic features and the presence of cats in the environment, low hygiene water systems and livestock that are mostly dependent on outdoor drinking and grazing. There was no significant association between IgM and age grouping ( χ 2 = 6.660 , P = 0.840 nor for IgG ( χ 2 = 8.136 , P = 0.43 ). The results of this study may be considered the starting point to promote the awareness about parasitic infections in ruminants in Pakistan in order to prevent this infection from further spreading.

Fasciola hepatica larval development within the intermediate host.

2021 ◽  
pp. 23-64
Author(s):  
Gilles Dreyfuss ◽  
Philippe Sindou ◽  
Philippe Hourdin ◽  
Philippe Vignoles ◽  
Daniel Rondelaud
Keyword(s):  
Intermediate Host ◽  
Larval Development ◽  
Fasciola Hepatica ◽  
Parasitic Infections ◽  
Snail Species ◽  
Larval Behavior ◽  
Host Snail

Abstract This book chapter focuses on host snail species and larval behavior forms in snails, and features of parasitic infections in naturally or experimentally infected snails, or in coinfected snails.

The Southern Sea Otter

1987 ◽  
pp. 456-477
Author(s):  
Wilbur N. Ladd ◽  
Marianne L. Riedman
Keyword(s):  
Sea Otter ◽  
Southern Sea Otter

Parasitic Infections

2012 ◽  
pp. 190-217
Author(s):  
Jon E. Rosenblatt ◽  
Bobbi S. Pritt
Keyword(s):  
Plasmodium Falciparum ◽  
Toxoplasma Gondii ◽  
Entamoeba Histolytica ◽  
Giardia Lamblia ◽  
Babesia Microti ◽  
Parasitic Infections ◽  
Blastocystis Hominis ◽  
Different Types ◽  
Eukaryotic Organisms ◽  
Parasitic Worms

This chapter covers protozoa, helminths, and arthropods. 1. Protozoa are single-celled, microscopic eukaryotic organisms like amebae and Giardia. Helminths are parasitic worms including nematodes (roundworms), cestodes (tapeworms), and trematodes (flukes). Arthropods, like ticks and mites, are generally considered parasites. Specific organisms reviewed include Giardia lamblia, Cyclospora cayetanensis, Blastocystis hominis, Entamoeba histolytica, Plasmodium falciparum, Babesia microti, and Toxoplasma gondii. Diagnosis and treatment of different types of infection are also reviewed.

Serological evidence of Toxoplasma gondii infection in captive marine mammals in Mexico

2012 ◽  
Vol 184 (2-4) ◽  
pp. 321-324 ◽  
Author(s):  
C. Alvarado-Esquivel ◽  
R. Sánchez-Okrucky ◽  
J.P. Dubey
Keyword(s):  
Toxoplasma Gondii ◽  
Marine Mammals ◽  
Serological Evidence ◽  
Toxoplasma Gondii Infection

scholarly journals NADPH Oxidase and Guanylate Binding Protein 5 Restrict Survival of Avirulent Type III Strains of Toxoplasma gondii in Naive Macrophages

mBio ◽  
2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Sumit K. Matta ◽  
Kelley Patten ◽  
Quiling Wang ◽  
Bae-Hoon Kim ◽  
John D. MacMicking ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Nadph Oxidase ◽  
Binding Protein ◽  
Parasitic Infections ◽  
Type I ◽  
Content Type ◽  
Innate Defense ◽  
Type Iii ◽  
Ifn Γ ◽  
Guanylate Binding Protein

ABSTRACT Phagocytic cells are the first line of innate defense against intracellular pathogens, and yet Toxoplasma gondii is renowned for its ability to survive in macrophages, although this paradigm is based on virulent type I parasites. Surprisingly, we find that avirulent type III parasites are preferentially cleared in naive macrophages, independent of gamma interferon (IFN-γ) activation. The ability of naive macrophages to clear type III parasites was dependent on enhanced activity of NADPH oxidase (Nox)-generated reactive oxygen species (ROS) and induction of guanylate binding protein 5 (Gbp5). Macrophages infected with type III parasites (CTG strain) showed a time-dependent increase in intracellular ROS generation that was higher than that induced by type I parasites (GT1 strain). The absence of Nox1 or Nox2, gp91 subunit isoforms of the Nox complex, reversed ROS-mediated clearance of CTG parasites. Consistent with this finding, both Nox1−/− and Nox2−/− mice showed higher susceptibility to CTG infection than wild-type mice. Additionally, Gbp5 expression was induced upon infection and the enhanced clearance of CTG strain parasites was reversed in Gbp5−/− macrophages. Expression of a type I ROP18 allele in CTG prevented clearance in naive macrophages, suggesting that it plays a role counteracting Gbp5. Although ROS and Gbp5 have been linked to activation of the NLRP3 inflammasome, clearance of CTG parasites did not rely on induction of pyroptosis. Collectively, these findings reveal that not all strains of T. gondii are adept at avoiding clearance in macrophages and define new roles for ROS and Gbps in controlling this important intracellular pathogen. IMPORTANCE Toxoplasma infections in humans and other mammals are largely controlled by IFN-γ produced by the activated adaptive immune system. However, we still do not completely understand the role of cell-intrinsic functions in controlling Toxoplasma or other apicomplexan infections. The present work identifies intrinsic activities in naive macrophages in counteracting T. gondii infection. Using an avirulent strain of T. gondii, we highlight the importance of Nox complexes in conferring protection against parasite infection both in vitro and in vivo. We also identify Gbp5 as a novel macrophage factor involved in limiting intracellular infection by avirulent strains of T. gondii. The rarity of human infections caused by type III strains suggests that these mechanisms may also be important in controlling human toxoplasmosis. These findings further extend our understanding of host responses and defense mechanisms that act to control parasitic infections at the cellular level.

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