-
Nucleic Acids Research Jan 2022Since 2005, the Pathogen-Host Interactions Database (PHI-base) has manually curated experimentally verified pathogenicity, virulence and effector genes from fungal,...
Since 2005, the Pathogen-Host Interactions Database (PHI-base) has manually curated experimentally verified pathogenicity, virulence and effector genes from fungal, bacterial and protist pathogens, which infect animal, plant, fish, insect and/or fungal hosts. PHI-base (www.phi-base.org) is devoted to the identification and presentation of phenotype information on pathogenicity and effector genes and their host interactions. Specific gene alterations that did not alter the in host interaction phenotype are also presented. PHI-base is invaluable for comparative analyses and for the discovery of candidate targets in medically and agronomically important species for intervention. Version 4.12 (September 2021) contains 4387 references, and provides information on 8411 genes from 279 pathogens, tested on 228 hosts in 18, 190 interactions. This provides a 24% increase in gene content since Version 4.8 (September 2019). Bacterial and fungal pathogens represent the majority of the interaction data, with a 54:46 split of entries, whilst protists, protozoa, nematodes and insects represent 3.6% of entries. Host species consist of approximately 54% plants and 46% others of medical, veterinary and/or environmental importance. PHI-base data is disseminated to UniProtKB, FungiDB and Ensembl Genomes. PHI-base will migrate to a new gene-centric version (version 5.0) in early 2022. This major development is briefly described.
Topics: Animals; Apicomplexa; Bacteria; Databases, Factual; Diplomonadida; Fungi; Host-Pathogen Interactions; Insecta; Internet; Nematoda; Phenotype; Phylogeny; Plants; User-Computer Interface; Virulence
PubMed: 34788826
DOI: 10.1093/nar/gkab1037 -
Scientific Reports Nov 2023Microturbellarians are abundant and ubiquitous members of marine meiofaunal communities around the world. Because of their small body size, these microscopic animals are...
Microturbellarians are abundant and ubiquitous members of marine meiofaunal communities around the world. Because of their small body size, these microscopic animals are rarely considered as hosts for parasitic organisms. Indeed, many protists, both free-living and parasitic ones, equal or surpass meiofaunal animals in size. Despite several anecdotal records of "gregarines", "sporozoans", and "apicomplexans" parasitizing microturbellarians in the literature-some of them dating back to the nineteenth century-these single-celled parasites have never been identified and characterized. More recently, the sequencing of eukaryotic microbiomes in microscopic invertebrates have revealed a hidden diversity of protist parasites infecting microturbellarians and other meiofaunal animals. Here we show that apicomplexans isolated from twelve taxonomically diverse rhabdocoel taxa and one species of proseriate collected in four geographically distinct areas around the Pacific Ocean (Okinawa, Hokkaido, and British Columbia) and the Caribbean Sea (Curaçao) all belong to the apicomplexan genus Rhytidocystis. Based on comprehensive molecular phylogenies of Rhabdocoela and Proseriata inferred from both 18S and 28S rDNA sequences, as well as a molecular phylogeny of Marosporida inferred from 18S rDNA sequences, we determine the phylogenetic positions of the microturbellarian hosts and their parasites. Multiple lines of evidence, including morphological and molecular data, show that at least nine new species of Rhytidocystis infect the microturbellarian hosts collected in this study, more than doubling the number of previously recognized species of Rhytidocystis, all of which infect polychaete hosts. A cophylogenetic analysis examining patterns of phylosymbiosis between hosts and parasites suggests a complex picture of overall incongruence between host and parasite phylogenies, and varying degrees of geographic signals and taxon specificity.
Topics: Animals; Platyhelminths; Phylogeny; Parasites; DNA, Ribosomal; Apicomplexa
PubMed: 38030717
DOI: 10.1038/s41598-023-48233-y -
Cellular Microbiology May 2014Plasmodium spp. and Toxoplasma gondii are important human and veterinary pathogens. These parasites possess an unusual double membrane structure located directly below... (Review)
Review
Plasmodium spp. and Toxoplasma gondii are important human and veterinary pathogens. These parasites possess an unusual double membrane structure located directly below the plasma membrane named the inner membrane complex (IMC). First identified in early electron micrograph studies, huge advances in genetic manipulation of the Apicomplexa have allowed the visualization of a dynamic, highly structured cellular compartment with important roles in maintaining the structure and motility of these parasites. This review summarizes recent advances in the field and highlights the changes the IMC undergoes during the complex life cycles of the Apicomplexa.
Topics: Intracellular Membranes; Locomotion; Microscopy, Electron; Models, Biological; Plasmodium; Toxoplasma
PubMed: 24612102
DOI: 10.1111/cmi.12285 -
Parasites & Vectors May 2019The epidemiology of feline vector-borne pathogens (FeVBPs) has been less investigated in cats than in dogs. The present study assessed the prevalence of Rickettsia spp.,...
BACKGROUND
The epidemiology of feline vector-borne pathogens (FeVBPs) has been less investigated in cats than in dogs. The present study assessed the prevalence of Rickettsia spp., Babesia spp., Cytauxzoon spp. and Leishmania infantum infections in cat populations living in central Italy, by molecular and serological tools.
RESULTS
A total of 286 healthy cats were randomly selected from catteries and colonies in central Italy. Peripheral blood and conjunctival swab (CS) samples were collected during surgical procedures for regional neutering projects. Sera were analysed by IFAT to detect anti-Rickettsia felis, R. conorii, Babesia microti and Leishmania IgG antibodies using commercial and home-made antigens. DNA extracted from buffy coats (BCs) was tested for Rickettsia spp., and Piroplasmida species, including Cytauxzoon spp. and Babesia spp. by PCR. Buffy coats and CS samples were assayed by a nested (n)-PCR for Leishmania spp. Sixty-two cats (21.67%) were seropositive to at least one of the tested pathogens. The serological assay revealed 23 (8.04%) and 18 (6.29%) positive cats for R. felis and R. conorii, respectively, with low titers (1/64-1/128). No antibodies against B. microti were detected. Neither Rickettsia nor Piroplasmida DNA were amplified using the specific PCR assays. Thirty-one cats (10.83%) tested positive to anti-Leishmania IgG, with titers ranging from 1:40 to 1:160 and 45 animals (15.73%) tested positive to Leishmania CS n-PCR, whereas none of the animals tested positive to BC n-PCR. Considering the results obtained by IFAT and CS n-PCR, a moderate agreement between the two tests was detected (κ = 0.27).
CONCLUSIONS
The results of the serological and molecular surveys showed a moderate exposure to Leishmania in the investigated cats and highlighted the limited molecular diagnostic value of BC versus CS samples for this pathogen. Conversely no evidence supported the circulation of Cytauxzoon spp. in domestic cats, in contrast with previous detections in European wild cats in the same areas monitored. The low positive titres for R. felis in association with no DNA BC amplification prevent speculation on the exposure of feline populations to this FeVBP due to the cross-reactivity existing within spotted fever group rickettsiosis (SFGR).
Topics: Animals; Apicomplexa; Babesia; Cat Diseases; Cats; Communicable Diseases, Emerging; Cross-Sectional Studies; Female; Italy; Leishmania infantum; Male; Protozoan Infections, Animal; Rickettsia; Rickettsia Infections
PubMed: 31046822
DOI: 10.1186/s13071-019-3409-8 -
Parasites & Vectors Feb 2023Apicomplexan haemoparasites are protozoans that infect a variety of domestic and wild animal species, as well as humans. Data regarding haemoprotozoans in domestic cats...
BACKGROUND
Apicomplexan haemoparasites are protozoans that infect a variety of domestic and wild animal species, as well as humans. Data regarding haemoprotozoans in domestic cats are limited; therefore, the aim of this study was to assess the occurrence of Babesia spp., Cytauxzoon spp., and Hepatozoon spp. in domestic cats in Romania using molecular tools.
METHODS
Blood samples from 371 domestic cats were screened for the presence of piroplasmids. All samples that yielded a visible band in agarose gels were subsequently tested by specific assays targeting the 18S rDNA of Babesia spp., Cytauxzoon spp., and Hepatozoon spp. Moreover, nested PCR assays targeting mitochondrial genes of Babesia spp. were used for screening of all Babesia spp. 18S rDNA-positive samples.
RESULTS
From the total number of sampled cats, 19.4% were positive in the PCR assay targeting piroplasmids. Babesia spp. were identified in 15.1% of cats, while 0.5% were positive for Hepatozoon spp. Molecular analyses confirmed the presence of Babesia canis. No samples were positive for Cytauxzoon spp.
CONCLUSIONS
The high infection rates of domestic cats with Babesia spp. and the need for species differentiation highlight the importance of mitochondrial genes as targets for molecular protocols.
Topics: Humans; Animals; Cats; Romania; Babesia; Piroplasmida; Animals, Wild; Eucoccidiida
PubMed: 36747203
DOI: 10.1186/s13071-023-05683-7 -
Trends in Parasitology Oct 2022The apicoplast, a relict plastid found in most species of the phylum Apicomplexa, harbors the ferredoxin redox system which supplies electrons to enzymes of various... (Review)
Review
The apicoplast, a relict plastid found in most species of the phylum Apicomplexa, harbors the ferredoxin redox system which supplies electrons to enzymes of various metabolic pathways in this organelle. Recent reports in Toxoplasma gondii and Plasmodium falciparum have shown that the iron-sulfur cluster (FeS)-containing ferredoxin is essential in tachyzoite and blood-stage parasites, respectively. Here we review ferredoxin's crucial contribution to isoprenoid and lipoate biosynthesis as well as tRNA modification in the apicoplast, highlighting similarities and differences between the two species. We also discuss ferredoxin's potential role in the initial reductive steps required for FeS synthesis as well as recent evidence that offers an explanation for how NADPH required by the redox system might be generated in Plasmodium spp.
Topics: Apicomplexa; Apicoplasts; Electrons; Ferredoxins; Iron; NADP; Oxidation-Reduction; Plasmodium falciparum; RNA, Transfer; Sulfur; Terpenes; Toxoplasma
PubMed: 35999149
DOI: 10.1016/j.pt.2022.08.002 -
Proceedings. Biological Sciences Jun 2010The phylum Apicomplexa includes a large group of protozoan parasites responsible for a wide range of animal and human diseases. Destructive pathogens, such as Plasmodium... (Review)
Review
The phylum Apicomplexa includes a large group of protozoan parasites responsible for a wide range of animal and human diseases. Destructive pathogens, such as Plasmodium falciparum and Plasmodium vivax, causative agents of human malaria, Cryptosporidium parvum, responsible of childhood diarrhoea, and Toxoplasma gondii, responsible for miscarriages and abortions in humans, are frequently associated with HIV immunosuppression in AIDS patients. The lack of effective vaccines, along with years of increasing pressure to eradicate outbreaks with the use of drugs, has favoured the formation of multi-drug resistant strains in endemic areas. Almost all apicomplexan of medical interest contain two endosymbiotic organelles that contain their own mitochondrial and apicoplast DNA. Apicoplast is an attractive target for drug testing because in addition to harbouring singular metabolic pathways absent in the host, it also has its own transcription and translation machinery of bacterial origin. Accordingly, apicomplexan protozoa contain an interesting mixture of enzymes to unwind DNA from eukaryotic and prokaryotic origins. On the one hand, the main mechanism of DNA unwinding includes the scission of one-type I-or both DNA strands-type II eukaryotic topoisomerases, establishing transient covalent bonds with the scissile end. These enzymes are targeted by camptothecin and etoposide, respectively, two natural drugs whose semisynthetic derivatives are currently used in cancer chemotherapy. On the other hand, DNA gyrase is a bacterial-borne type II DNA topoisomerase that operates within the apicoplast and is effectively targeted by bacterial antibiotics like fluoroquinolones and aminocoumarins. The present review is an update on the new findings concerning topoisomerases in apicomplexan parasites and the role of these enzymes as targets for therapeutic agents.
Topics: Animals; Antiparasitic Agents; Apicomplexa; DNA Topoisomerases, Type I; Drug Design
PubMed: 20200034
DOI: 10.1098/rspb.2009.2176 -
Memorias Do Instituto Oswaldo Cruz Mar 2003Cell fractionation, a methodological strategy for obtaining purified organelle preparations, has been applied successfully to parasitic protozoa by a number of... (Review)
Review
Cell fractionation, a methodological strategy for obtaining purified organelle preparations, has been applied successfully to parasitic protozoa by a number of investigators. Here we present and discuss the work of several groups that have obtained highly purified subcellular fractions from trypanosomatids, Apicomplexa and trichomonads, and whose work have added substantially to our knowledge of the cell biology of these parasites.
Topics: Animals; Apicomplexa; Cell Fractionation; Cell Membrane; Microscopy, Electron; Organelles; Trichomonas; Trypanosomatina
PubMed: 12764429
DOI: 10.1590/s0074-02762003000200001 -
Journal of Biomedicine & Biotechnology 2012Apicomplexan parasites comprise a broad variety of protozoan parasites, including Toxoplasma gondii, Plasmodium, Eimeria, and Cryptosporidium species. Being... (Review)
Review
Apicomplexan parasites comprise a broad variety of protozoan parasites, including Toxoplasma gondii, Plasmodium, Eimeria, and Cryptosporidium species. Being intracellular parasites, the success in establishing pathogenesis relies in their ability to infect a host-cell and replicate within it. Protein palmitoylation is known to affect many aspects of cell biology. Furthermore, palmitoylation has recently been shown to affect important processes in T. gondii such as replication, invasion, and gliding. Thus, this paper focuses on the importance of protein palmitoylation in the pathogenesis of apicomplexan parasites.
Topics: Apicomplexa; Lipoylation; Protozoan Proteins
PubMed: 23093847
DOI: 10.1155/2012/483969 -
Frontiers in Cellular and Infection... 2020Over the past decade, we have witnessed significant progresses in understanding gene regulation in Apicomplexa including the human malaria parasite, . This parasite... (Review)
Review
Over the past decade, we have witnessed significant progresses in understanding gene regulation in Apicomplexa including the human malaria parasite, . This parasite possesses the ability to convert in multiple stages in various hosts, cell types, and environments. Recent findings indicate that is talented at using efficient and complementary molecular mechanisms to ensure a tight control of gene expression at each stage of its life cycle. Here, we review the current understanding on the contribution of the epigenome, atypical transcription factors, and chromatin organization to regulate stage conversion in . The adjustment of these regulatory mechanisms occurring during the progression of the life cycle will be extensively discussed.
Topics: Gene Expression Regulation; Humans; Malaria, Falciparum; Plasmodium; Plasmodium falciparum; Transcription Factors
PubMed: 33425787
DOI: 10.3389/fcimb.2020.618454