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Journal of Microbiological Methods Jul 2024As data accumulate in GenBank, the difficulties of delineating species of Cryptosporidium based on nuclear small subunit ribosomal RNA (ssu rRNA) gene information alone... (Review)
Review
As data accumulate in GenBank, the difficulties of delineating species of Cryptosporidium based on nuclear small subunit ribosomal RNA (ssu rRNA) gene information alone becomes increasingly evident. Here, we summarize currently available evidence suggesting that several ssu rDNA sequences primarily referred to as Cryptosporidium suis (some of them from non-suid hosts) should be considered Cryptosporidium occultus.
Topics: Cryptosporidium; Cryptosporidiosis; Animals; DNA, Ribosomal; DNA, Protozoan; Humans; Phylogeny; Sequence Analysis, DNA
PubMed: 38777182
DOI: 10.1016/j.mimet.2024.106957 -
Trends in Parasitology Jun 2022γ-aminobutyric acid (GABA) is a nonstructural amino acid that serves diverse functions in unicellular and multicellular organisms. Besides its widely established role... (Review)
Review
γ-aminobutyric acid (GABA) is a nonstructural amino acid that serves diverse functions in unicellular and multicellular organisms. Besides its widely established role in mammals as an inhibitory neurotransmitter, the diverse biological roles and metabolism of GABA in protozoan parasites have begun to be unveiled. GABA acts as either the intracellular signal or cell-to-cell messenger to mediate a variety of cellular responses that protect the parasites from environmental and host-derived stress. Moreover, GABA metabolism was found to be tightly regulated, involving protein machinery confined to the protozoa lineage. Meanwhile, host-parasite GABAergic interaction plays a role in the pathogenesis and disease manifestation of protozoan infections. Therefore, the GABAergic system apparently is broadly involved in essential biological and pathophysiological processes and is well conserved in parasitic and free-living protozoa.
Topics: Animals; Host-Parasite Interactions; Mammals; Parasites; Protozoan Infections; gamma-Aminobutyric Acid
PubMed: 35264298
DOI: 10.1016/j.pt.2022.02.004 -
Journal of Comparative Pathology Jan 2021An adult American Quarter Horse gelding with a history of weight loss presented with an acute onset of colic, fever, soft faeces and elevated liver enzymes. At necropsy,...
An adult American Quarter Horse gelding with a history of weight loss presented with an acute onset of colic, fever, soft faeces and elevated liver enzymes. At necropsy, there were gastric mucosal masses and evidence of caecal necrosis. Histologically, the masses were lymph nodes with granulomatous inflammation and areas of liquefactive necrosis. Within and surrounding necrotic areas were free and intrahistiocytic clusters of protozoal tachyzoites. Similar but milder inflammation was evident in the spleen, lungs and liver. Necrotizing typhlitis was also evident. Immunolabelling for Toxoplasma gondii was positive and the ultrastructural morphology of the protozoa was compatible with T. gondii. Although studies have shown seropositivity to T. gondii in horses throughout the world, this is the first report of clinical toxoplasmosis in this species.
Topics: Animals; Fatal Outcome; Horse Diseases; Horses; Liver; Lung; Male; Spleen; Toxoplasma; Toxoplasmosis, Animal
PubMed: 33494904
DOI: 10.1016/j.jcpa.2020.11.004 -
MBio Dec 2022Genetic exchange between different strains in the sand fly vector has been experimentally demonstrated and is supported by population genetic studies. In nature,...
Genetic exchange between different strains in the sand fly vector has been experimentally demonstrated and is supported by population genetic studies. In nature, opportunities for interstrain mating are restricted to flies biting multiply infected hosts or through multiple bites of different hosts. In contrast, self-mating could occur in any infected sand fly. By crossing two recombinant lines derived from the same Leishmania major strain, each expressing a different drug-resistance marker, self-hybridization in L. major was confirmed in a natural sand fly vector, , and in frequencies comparable to interstrain crosses. We provide the first high resolution, whole-genome sequencing analysis of large numbers of selfing progeny, their parents, and parental subclones. Genetic exchange consistent with classical meiosis is supported by the biallelic inheritance of the rare homozygous single nucleotide polymorphisms (SNPs) that arose by mutation during the generation of the parental clones. In contrast, heterozygous SNPs largely failed to be transmitted in Mendelian ratios for reasons not understood. SNPs that were heterozygous in both parents, however, recombined to produce homozygous alleles in some hybrids. For trisomic chromosomes present in both parents, transmittal to the progeny was only altered by self-hybridization, involving a gain or loss of somy in frequencies predicted by a meiotic process. Whole-genome polyploidization was also observed in the selfing progeny. Thus, self-hybridization in , with its potential to occur in any infected sand fly, may be an important source of karyotype variation, loss of heterozygosity, and functional diversity. are parasitic protozoa that cause a wide spectrum of diseases collectively known as the leishmaniases. Sexual reproduction in has been proposed as an important source of genetic diversity and has been formally demonstrated to occur inside the sand fly vector midgut. Nevertheless, in the wild, opportunities for genetic exchange between different species or strains are restricted by the capacity of different strains to colonize the same sand fly. In this work, we report the first high resolution, whole-genome sequence analysis of intraclonal genetic exchange as a type of self-mating in Our data reveal that self-hybridization can occur with comparable frequency as interstrain mating under experimental lab conditions, leading to important genomic alterations that can potentially take place within every naturally infected sand fly.
Topics: Animals; Leishmania major; Phlebotomus; Psychodidae; Reproduction; Mutation
PubMed: 36394334
DOI: 10.1128/mbio.02858-22 -
Acta Parasitologica Mar 2024As a result of environmental imbalances of anthropogenic origin, the potential for transmission of parasites and viruses between different primates, including humans,... (Review)
Review
PURPOSE
As a result of environmental imbalances of anthropogenic origin, the potential for transmission of parasites and viruses between different primates, including humans, might increase. Thus, parasitic studies have great relevance to primatology, which motivated us to conduct a literature review to synthesize the information available in American primates of the Callithrix genus.
METHODS
We carried out the bibliographic search on the main groups of parasites (protozoa, helminths, arthropods, ectoparasites) and viruses found in Callithrix in Brazil in search platforms and consider all manuscript that appeared in search engines, published between the years 1910 and December 2022. In each selected article, the following information was recorded: the host species; parasite taxa; scientific classification of the parasite; host habitat (free-living, captive); diagnostic technique; state; and bibliographic reference. Data were tabulated and arranged in a parasite-host table.
RESULTS
Some endemic genera, such as Callithrix, are widely distributed geographically across Brazil and have characteristics of adaptation to different habitats due to their flexibility in diet and behavior. These factors can make them subject to a greater diversity of parasites and viruses in the country. Here, we identified 68 parasitic taxa, belonging to the clades protozoa (n = 22), helminths (n = 34), ectoparasites (n = 7), and viruses (n = 5). Out of this total, 19 have zoonotic potential. Of the six existing marmoset species, Callithrix jacchus was the most frequent in studies, and Callithrix flaviceps did not have reports. All regions of the country had occurrences, mainly the Southeast, where 54% of the cases were reported. In 46% of the reported parasites and viruses, it was not possible to identify the corresponding species.
CONCLUSION
We conclude that in part of the works the identification methods are not being specific, which makes it difficult to identify the species that affects Callithrix spp. Furthermore, the studies present geographic disparities, being concentrated in the southeast of the country, making it impossible to have a more uniform analysis of the findings. Thus, it is observed that information about parasites and viruses is incipient in the genus Callithrix in Brazil.
Topics: Animals; Brazil; Callithrix; Parasites; Monkey Diseases; Viruses; Virus Diseases; Parasitic Diseases, Animal
PubMed: 38184509
DOI: 10.1007/s11686-023-00766-y -
Veterinary Medicine and Science Mar 2023Fish is a great nutritious food and provides quality protein and a variety of vitamins and minerals. This contributes significantly to the economy and food security in... (Review)
Review
BACKGROUND
Fish is a great nutritious food and provides quality protein and a variety of vitamins and minerals. This contributes significantly to the economy and food security in Iran. However, there are safety concerns related to the presence of zoonotic parasites.
OBJECTIVES
The objective of this study is, therefore, to review fish-borne zoonotic parasites in Iran.
METHODS
Keywords such as fish-borne, parasites, zoonotic, Iran, and some names of fish-borne zoonotic parasites were searched in databases including PubMed, Science Direct, Elsevier, SID, Magiran, Irandoc, Google Scholar and the World Health Organization.
RESULTS
The most common fish-borne parasites with zoonotic potential identified in reports in the literature were the protozoa Balantidium spp., Myxobolus spp. and Sarcosystis sp.; the trematodes Heterophyes heterophyes and Clinostomum complanatum; the cestodes Ligula intestinalis and Diphyllobothrium latum; the nematodes Pseudoterranova sp., Anisakis spp., Contracaecum spp., Raphidascaris spp., Eustrongylides spp. and Capillaria sp.; and the acanthocephal Corynosoma spp.
CONCLUSIONS
The potential risk factors for the transmission of fish-borne zoonotic parasites to humans are consumption of raw or undercooked infected fish, contact with contaminated water and contact with infected fish. There is a need for epidemiological surveillance of fish for parasites with zoonotic potential and of occurrence of infections in humans to better understand the public health significance and design prevention programs.
Topics: Animals; Humans; Parasites; Iran; Fishes; Public Health; Trematoda
PubMed: 36271486
DOI: 10.1002/vms3.981 -
Bioorganic & Medicinal Chemistry Letters Nov 2022Chagas disease and Human African trypanosomiasis (HAT) are caused by Trypanosoma cruzi, T. brucei rhodesiense or T. b. gambiense parasites, respectively; while... (Review)
Review
Chagas disease and Human African trypanosomiasis (HAT) are caused by Trypanosoma cruzi, T. brucei rhodesiense or T. b. gambiense parasites, respectively; while Leishmania is caused by parasites from the Leishmania genus. In recent years, many efforts have been addressed to develop inhibitors against these parasites, especially nitro-containing derivatives, which can interfere with essential enzymes from the protozoa. In this review, all anti-trypanosomatidae nitrocompounds reported so far are shown herein, highlighting their activities and SAR analyses, providing all the benefits and problems associated with this ambiguous chemical group. Finally, this review paper will be useful for many research teams around the world, which are searching for novel trypanocidal and leishmanicidal agents.
Topics: Animals; Humans; Leishmania; Nitro Compounds; Parasites; Trypanocidal Agents; Trypanosoma cruzi; Trypanosomiasis, African
PubMed: 36030001
DOI: 10.1016/j.bmcl.2022.128930 -
ACS Chemical Neuroscience Jun 2023is a pathogenic amoeba that causes a fulminant and rapidly progressive disease affecting the central nervous system called primary amoebic meningoencephalitis (PAM)....
is a pathogenic amoeba that causes a fulminant and rapidly progressive disease affecting the central nervous system called primary amoebic meningoencephalitis (PAM). Moreover, the disease is fatal in more than 97% of the reported cases, mostly affecting children and young people after practicing aquatic activities in nontreated fresh and warm water bodies contaminated with these amoebae. Currently, the treatment of primary amoebic meningoencephalitis is based on a combination of different antibiotics and antifungals, which are not entirely effective and lead to numerous side effects. In the recent years, research against PAM is focused on the search of novel, less toxic, and fully effective antiamoebic agents. Previous studies have reported the activity of cyano-substituted molecules in different protozoa. Therefore, the activity of 46 novel synthetic cyanomethyl vinyl ethers (QOET-51 to QOET-96) against two type strains of (ATCC 30808 and ATCC 30215) was determined. The data showed that QOET-51, QOET-59, QOET-64, QOET-67, QOET-72, QOET-77, and QOET-79 were the most active molecules. In fact, the selectivity index (CC/IC) was sixfold higher when compared to the activities of the drugs of reference. In addition, the mechanism of action of these compounds was studied, with the aim to demonstrate the induction of a programmed cell death process in .
Topics: Child; Humans; Adolescent; Naegleria fowleri; Central Nervous System Protozoal Infections; Amoeba; Ethers
PubMed: 37167960
DOI: 10.1021/acschemneuro.3c00110 -
Anaerobe Jun 2024Ciliate protozoa are key members of the microbial community of the rumen. Their study is important to the health and productivity of cattle, which are their hosts.... (Review)
Review
Ciliate protozoa are key members of the microbial community of the rumen. Their study is important to the health and productivity of cattle, which are their hosts. However, there have been persistent challenges in culturing this microbial group in the laboratory. This review will sum up recent advances along with these persistent challenges. Protozoa have been maintained in three types of cultures (ex vivo, in vitro batch, in vitro continuous). Ex vivo cultures are prepared readily from rumen contents by washing away contaminating cells (e.g., bacteria). They have been useful in making basic observations of metabolism, such as which types of fermentation products protozoa form. However, these cultures can be maintained for only short periods (minutes or hours). In vitro batch and in vitro continuous cultures can be used in longer experiments (weeks or longer). However, it is not currently possible to maintain protozoa in these cultures unless bacteria are also present. We conclude the review with a protocol for preparing ex vivo cultures of protozoa. Our protocol has been standardized and used successfully across animal diets, users, and institutions. We anticipate this review will prepare others to culture rumen ciliate protozoa and reach new insights into this important microbial group.
Topics: Rumen; Animals; Ciliophora; Cattle
PubMed: 38782297
DOI: 10.1016/j.anaerobe.2024.102865 -
Parasitology Research Jul 2019Coccidiosis is a parasitic disease of a wide variety of animals caused by coccidian protozoa. The coccidia are responsible for major economic losses of the livestock... (Review)
Review
Coccidiosis is a parasitic disease of a wide variety of animals caused by coccidian protozoa. The coccidia are responsible for major economic losses of the livestock industry. For example, the annual cost due to coccidiosis to the global poultry industry has been estimated to exceed US$ 3 billion annually. Currently available drugs for the control of this disease are either polyether ionophorous antibiotics that are derived from fermentation products, or synthetic compounds, produced by chemical synthesis. Unfortunately, no new drugs in either category have been approved for use for decades. Resistance has been documented for all those of the drugs currently employed and therefore the discovery of novel drugs with unique modes of action is imperative if chemotherapy is to remain the principal means to control this disease. This chapter aims to give an overview of the efficacy and mode of action of the current compounds used to control coccidiosis in livestock and provides a brief outlook of research needs for the future.
Topics: Animals; Coccidia; Coccidiosis; Coccidiostats; Livestock; Poultry; Poultry Diseases
PubMed: 31152233
DOI: 10.1007/s00436-019-06343-5