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Parasites & Vectors Jan 2021Toxoplasma 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... (Review)
Review
Toxoplasma 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.
Topics: Animals; Behavior, Animal; Cats; Fear; Host-Parasite Interactions; Humans; Life Cycle Stages; Odorants; Rodentia; Toxoplasma; Toxoplasmosis, Animal
PubMed: 33494777
DOI: 10.1186/s13071-020-04528-x -
Revue Scientifique Et Technique... Aug 2015Babesiosis is the disease caused by infection of the erythrocytes of mammals by Babesia species, which are Apicomplexa protozoa belonging to the suborder Piroplasmidea... (Review)
Review
Babesiosis is the disease caused by infection of the erythrocytes of mammals by Babesia species, which are Apicomplexa protozoa belonging to the suborder Piroplasmidea and the family Babesiidae. They are different from the Theileriidae, which can also infect white blood cells and endothelial cells. Babesiosis is one of the most important tick-borne infectious diseases of domestic and wild mammals and still poses significant diagnostic and therapeutic challenges for veterinary practitioners around the world. It is an increasing problem worldwide because of the expansion of tick habitats and the increased mobility of animals, which promote the spread of parasites into new geographical areas. Babesia species can, exceptionally, infect humans, especially splenectomised or immunocompromised individuals. The majority of human cases involve B. microti, a parasite of rodents, but human infections may also be caused by B. divergens, which infects cattle, or by Babesia related to B. odocoilei, which infect cervids. The majority of new developments, in regard to taxonomy, epidemiology, pathogenesis and control, concern canine babesiosis, whereas piroplasmosis in horses or cattle retains the classical description, therefore the focus of this article will be on infection in dogs.
Topics: Animals; Babesia; Babesiosis; Europe; Humans
PubMed: 26601462
DOI: 10.20506/rst.34.2.2385 -
Philosophical Transactions of the Royal... Jul 2018Birds have many kinds of internal and external parasites, including viruses, bacteria and fungi, as well as protozoa, helminths and arthropods. Because parasites have... (Review)
Review
Birds have many kinds of internal and external parasites, including viruses, bacteria and fungi, as well as protozoa, helminths and arthropods. Because parasites have negative effects on host fitness, selection favours the evolution of anti-parasite defences, many of which involve behaviour. We provide a brief review of anti-parasite behaviours in birds, divided into five major categories: (i) body maintenance, (ii) nest maintenance, (iii) avoidance of parasitized prey, (iv) migration and (v) tolerance. We evaluate the adaptive significance of the different behaviours and note cases in which additional research is particularly needed. We briefly consider the interaction of different behaviours, such as sunning and preening, and how behavioural defences may interact with other forms of defence, such as immune responses. We conclude by suggesting some general questions that need to be addressed concerning the nature of anti-parasite behaviour in birds.This article is part of the Theo Murphy meeting issue 'Evolution of pathogen and parasite avoidance behaviours'.
Topics: Adaptation, Biological; Animal Migration; Animals; Avoidance Learning; Birds; Feeding Behavior; Grooming; Host-Parasite Interactions; Interpersonal Relations; Nesting Behavior
PubMed: 29866911
DOI: 10.1098/rstb.2017.0196 -
Przeglad Epidemiologiczny 2015Babesiosis is an emerging parasitic, anthropo-zoonotic tick-borne disease, seldom diagnosed in humans. Caused by Protozoa, Babesia (also called Piroplasma)... (Review)
Review
Babesiosis is an emerging parasitic, anthropo-zoonotic tick-borne disease, seldom diagnosed in humans. Caused by Protozoa, Babesia (also called Piroplasma) intraerytrocytic piriform microorganism. Infection of vertebrates is transmitted by ticks. Out of more than 100 Babesia species/genotypes described so far, only some were diagnosed in infected humans, mostly B. microti, B. divergens and B. venatorum (Babesia sp. EU1). Infection in humans is often asymptomatic or mild but is of a particular risk for asplenic individuals, those with congenital or acquired immunodeficiencies, and elderly. Infections transmitted with blood and blood products raise concerns in hemotherapy. Epidemiological situation of babesiosis varies around the world. In Europe, no increase in the number of cases was reported, but in the USA its prevalence is increasing and extension of endemic areas is observed. The aim of this publication is to describe the problems connected with the current epidemiological situation, diagnosis and treatment of human babesiosis with regard to clinical status of patients.
Topics: Animals; Babesia; Babesiosis; Communicable Diseases, Emerging; Europe; Humans; Poland; Zoonoses
PubMed: 26519845
DOI: No ID Found -
The American Journal of Tropical... Sep 2016Historically, the diagnosis of soil-transmitted helminths (STHs) (e.g., Strongyloides stercoralis, Trichuris trichiura, Ancylostoma duodenale, Necator americanus, and... (Review)
Review
Historically, the diagnosis of soil-transmitted helminths (STHs) (e.g., Strongyloides stercoralis, Trichuris trichiura, Ancylostoma duodenale, Necator americanus, and Ascaris lumbricoides) has relied on often-insensitive microscopy techniques. Over the past several years, there has been an effort to use molecular diagnostics, particularly quantitative polymerase chain reaction (qPCR), to detect intestinal pathogens. While some platforms have been approved by regulatory bodies (e.g., Food and Drug Administration) to detect intestinal bacteria, viruses, and protozoa, there are no approved tests currently available for STH. Although studies comparing qPCR to microscopy methods for STH are imperfect, due in large part to a lack of a sufficient gold standard, they do show a significant increase in sensitivity and specificity of qPCR compared with microscopic techniques. These studies, as well as the advantages and disadvantages of using qPCR for STH diagnosis, are discussed. Guidelines for those designing future studies utilizing qPCR are proposed for optimizing results, as is the proposition for using standardized molecular diagnostics routinely for STH in clinical laboratories and for field-based studies when possible.
Topics: Helminthiasis; Humans; Molecular Diagnostic Techniques; Polymerase Chain Reaction; Sensitivity and Specificity; Soil
PubMed: 27481053
DOI: 10.4269/ajtmh.16-0266 -
Frontiers in Cellular and Infection... 2017Understanding host-pathogen-tick interactions remains a vitally important issue that might be better understood by basic research focused on each of the dyad interplays.... (Review)
Review
Understanding host-pathogen-tick interactions remains a vitally important issue that might be better understood by basic research focused on each of the dyad interplays. Pathogens gain access to either the vector or host during tick feeding when ticks are confronted with strong hemostatic, inflammatory and immune responses. A prominent example of this is the spp.-tick-vertebrate host relationship. spp. are intraerythrocytic apicomplexan organisms spread worldwide, with a complex life cycle. The presence of transovarial transmission in almost all the species is the main difference between their life cycle and that of other piroplasmida. With more than 100 species described so far, are the second most commonly found blood parasite of mammals after trypanosomes. The prevalence of spp. infection is increasing worldwide and is currently classified as an emerging zoonosis. and are the most frequent etiological agents associated with human babesiosis in North America and Europe, respectively. Although the -tick system has been extensively researched, the currently available prophylactic and control methods are not efficient, and chemotherapeutic treatment is limited. Studying the molecular changes induced by the presence of in the vector will not only elucidate the strategies used by the protozoa to overcome mechanical and immune barriers, but will also contribute toward the discovery of important tick molecules that have a role in vector capacity. This review provides an overview of the identified molecules involved in -tick interactions, with an emphasis on the fundamentally important ones for pathogen acquisition and transmission.
Topics: Animals; Antigens; Arthropod Proteins; Babesia; Babesiosis; Calreticulin; Disease Vectors; Glycoproteins; Host-Parasite Interactions; Salivary Glands; Tick-Borne Diseases; Ticks
PubMed: 29034218
DOI: 10.3389/fcimb.2017.00429 -
Anais Brasileiros de Dermatologia Mar 2018Ticks are blood-sucking arthropods that attach to human skin through oral devices causing diverse initial cutaneous manifestations, and may also transmit serious... (Review)
Review
Ticks are blood-sucking arthropods that attach to human skin through oral devices causing diverse initial cutaneous manifestations, and may also transmit serious infectious diseases. In certain situations, the Health Teams (and especially dermatologists) may face difficulties in identifying the lesions and associating them to the parasites. To assist them in clinical diagnosis, we suggest a classification of the skin manifestations in primary lesions, which occur by the attachment the tick to the host (for toxicity and the anticoagulant substances in the saliva and/or marked inflammation by the penetration and permanence of the mouthparts) and secondary lesions that are manifestations of infections caused by rickettsia, bacteria, protozoa and fungi inoculated by the ticks.
Topics: Animals; Humans; Skin; Skin Diseases, Parasitic; Tick Bites; Tick-Borne Diseases; Ticks
PubMed: 29723373
DOI: 10.1590/abd1806-4841.20186378 -
Nature Reviews. Microbiology Oct 2019Antimicrobial treatment failure threatens our ability to control infections. In addition to antimicrobial resistance, treatment failures are increasingly understood to... (Review)
Review
Antimicrobial treatment failure threatens our ability to control infections. In addition to antimicrobial resistance, treatment failures are increasingly understood to derive from cells that survive drug treatment without selection of genetically heritable mutations. Parasitic protozoa, such as Plasmodium species that cause malaria, Toxoplasma gondii and kinetoplastid protozoa, including Trypanosoma cruzi and Leishmania spp., cause millions of deaths globally. These organisms can evolve drug resistance and they also exhibit phenotypic diversity, including the formation of quiescent or dormant forms that contribute to the establishment of long-term infections that are refractory to drug treatment, which we refer to as 'persister-like cells'. In this Review, we discuss protozoan persister-like cells that have been linked to persistent infections and discuss their impact on therapeutic outcomes following drug treatment.
Topics: Antiprotozoal Agents; Biological Variation, Population; Chagas Disease; Drug Tolerance; Humans; Leishmania; Leishmaniasis; Malaria; Plasmodium; Toxoplasma; Toxoplasmosis; Treatment Failure; Trypanosoma cruzi
PubMed: 31444481
DOI: 10.1038/s41579-019-0238-x -
Developmental and Comparative Immunology Nov 2016Fish intestinal parasites cause direct mortalities and also morbidity, poor growth, higher susceptibility to opportunistic pathogens and lower resistance to stress. This... (Review)
Review
Fish intestinal parasites cause direct mortalities and also morbidity, poor growth, higher susceptibility to opportunistic pathogens and lower resistance to stress. This review is focused on microscopic parasites (Protozoa and Metazoa) that invade the gastrointestinal tract of fish. Intracellular parasites (mainly Microsporidia and Apicomplexa) evoke almost no host immune reaction while they are concealed in the cytoplasmic and nuclear compartments, and can even use fish cells (macrophages) as Trojan horses to spread in the host. Inflammatory reaction only appears when the parasite bursts infected cells. Immunity against extracellular parasites is depicted for the myxozoans Ceratonova shasta and Enteromyxum spp. The cellular and humoral innate responses and the production of antibodies are crucial for resolving some of these myxozoonoses, but an excessive inflammatory reaction (concerted by cytokines) can become a fatal pathophysiological consequence. The local immune response plays a key role, with numerous genes more strongly regulated in the intestine than at lymphohaematopoietic organs.
Topics: Animals; Apicomplexa; Fishes; Gastrointestinal Tract; Immune Evasion; Immunity, Innate; Inflammation; Microsporidia; Microsporidiosis; Myxozoa; Parasitic Diseases, Animal; Protozoan Infections
PubMed: 26828391
DOI: 10.1016/j.dci.2016.01.014 -
Clinical Microbiology and Infection :... Jan 2018
Topics: Aged; Diarrhea; Feces; Humans; Isospora; Isosporiasis; Male; Paraproteinemias
PubMed: 28712665
DOI: 10.1016/j.cmi.2017.07.009