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The Journal of Experimental Biology Jan 2013For millions of years, parasites have altered the behaviour of their hosts. Parasites can affect host behaviour by: (1) interfering with the host's normal immune-neural...
For millions of years, parasites have altered the behaviour of their hosts. Parasites can affect host behaviour by: (1) interfering with the host's normal immune-neural communication, (2) secreting substances that directly alter neuronal activity via non-genomic mechanisms and (3) inducing genomic- and/or proteomic-based changes in the brain of the host. Changes in host behaviour are often restricted to particular behaviours, with many other behaviours remaining unaffected. Neuroscientists can produce this degree of selectivity by targeting specific brain areas. Parasites, however, do not selectively attack discrete brain areas. Parasites typically induce a variety of effects in several parts of the brain. Parasitic manipulation of host behaviour evolved within the context of the manipulation of other host physiological systems (especially the immune system) that was required for a parasite's survival. This starting point, coupled with the fortuitous nature of evolutionary innovation and evolutionary pressures to minimize the costs of parasitic manipulation, likely contributed to the complex and indirect nature of the mechanisms involved in host behavioural control. Because parasites and neuroscientists use different tactics to control behaviour, studying the methods used by parasites can provide novel insights into how nervous systems generate and regulate behaviour. Studying how parasites influence host behaviour will also help us integrate genomic, proteomic and neurophysiological perspectives on behaviour.
Topics: Animals; Behavior; Behavior, Animal; Biological Evolution; Brain; Genomics; Host-Parasite Interactions; Humans; Immune System; Neuroimmunomodulation; Neurosciences; Parasites
PubMed: 23225861
DOI: 10.1242/jeb.073601 -
Biomolecules Apr 2020Studies on the parasite-host interaction may provide valuable information concerning the modulation of molecular mechanisms as well as of the host immune system during... (Review)
Review
Studies on the parasite-host interaction may provide valuable information concerning the modulation of molecular mechanisms as well as of the host immune system during infection. To date, it has been demonstrated that intestinal parasites may affect, among others, the processes of digestion in the gastrointestinal system of the host, thus limiting the elimination of the parasite, the immune response as well as inflammation. However, the most recent studies suggest that intestinal parasites may also affect modulation of the apoptosis pathway of the host. The present paper presents the latest scientific information on the influence of intestinal parasite species ( sp., sp., sp., sp., , , ) on the molecular mechanisms of apoptosis in intestinal epithelial cells. This paper stresses that the interdependency between the intestinal parasite and the host results from the direct effect of the parasite and the host's defense reactions, which lead to modulation of the apoptosis pathways (intrinsic and extrinsic). Moreover, the present paper presents the role of proteins involved in the mechanisms of apoptosis as well as the physiological role of apoptosis in the host's intestinal epithelial cells.
Topics: Animals; Apoptosis; Enterocytes; Host-Parasite Interactions; Humans; Intestinal Diseases, Parasitic; Parasites
PubMed: 32349424
DOI: 10.3390/biom10050674 -
Current Opinion in Microbiology Dec 2017
Topics: Animals; Host-Parasite Interactions; Humans; Parasites; Parasitic Diseases
PubMed: 29248118
DOI: 10.1016/j.mib.2017.11.028 -
Trends in Parasitology Oct 2015Nucleic acid extraction and sequencing of genes from organisms within environmental samples encompasses a variety of techniques collectively referred to as environmental... (Review)
Review
Nucleic acid extraction and sequencing of genes from organisms within environmental samples encompasses a variety of techniques collectively referred to as environmental DNA or 'eDNA'. The key advantages of eDNA analysis include the detection of cryptic or otherwise elusive organisms, large-scale sampling with fewer biases than specimen-based methods, and generation of data for molecular systematics. These are particularly relevant for parasitology because parasites can be difficult to locate and are morphologically intractable and genetically divergent. However, parasites have rarely been the focus of eDNA studies. Focusing on eukaryote parasites, we review the increasing diversity of the 'eDNA toolbox'. Combining eDNA methods with complementary tools offers much potential to understand parasite communities, disease risk, and parasite roles in broader ecosystem processes such as food web structuring and community assembly.
Topics: Animals; DNA; Ecosystem; Environmental Monitoring; Parasites; Parasitology
PubMed: 26433253
DOI: 10.1016/j.pt.2015.06.013 -
Molecular and Biochemical Parasitology Mar 2002Cysteine proteases play numerous indispensable roles in the biology of parasitic organisms. Aside from previously known general catabolic functions and protein... (Review)
Review
Cysteine proteases play numerous indispensable roles in the biology of parasitic organisms. Aside from previously known general catabolic functions and protein processing, cysteine proteases may be key to parasite immunoevasion, excystment/encystment, exsheathing and cell and tissue invasion. Parasite cysteine proteases are unusually immunogenic and have been exploited as serodiagnostic markers and vaccine targets. Although host homologues exist, parasite cysteine proteases have distinct structural and biochemical properties including, pH optima and stability, the alteration in peptide loops or domain extensions, diverse substrate specificity and cellular location. The disparate nature of parasite cysteine protease compared to the host orthologous proteins has opened opportunities for chemotherapy. This review will highlight recent research on the 'papain-like' class of cysteine proteases, the most abundant family, and the newly discovered class of asparaginyl-endopeptidases. Cysteine protease classification will be re-examined in light of the diversity uncovered within parasitic organisms.
Topics: Amino Acid Sequence; Animals; Cysteine Endopeptidases; Humans; Molecular Sequence Data; Parasites; Parasitic Diseases
PubMed: 11849701
DOI: 10.1016/s0166-6851(01)00438-8 -
Journal of Clinical Microbiology Feb 2019Parasite taxonomy continues to change as molecular and morphologic studies enhance our understanding of parasite relatedness. This minireview builds on the information...
Parasite taxonomy continues to change as molecular and morphologic studies enhance our understanding of parasite relatedness. This minireview builds on the information provided in the last taxonomy update in this journal to summarize new and revised clinically relevant human parasite taxonomic changes that have occurred in 2016 and 2017.
Topics: Animals; Humans; Parasites; Parasitic Diseases; Parasitology
PubMed: 30282786
DOI: 10.1128/JCM.01067-18 -
Scientific Reports Apr 2018Host quality is critical for parasites. The common cuckoo Cuculus canorus is a generalist avian brood parasite, but individual females show strong preference for a...
Host quality is critical for parasites. The common cuckoo Cuculus canorus is a generalist avian brood parasite, but individual females show strong preference for a specific host species. Here, we use three extensive datasets to investigate different host characteristics determining cuckoo host selection at the species level: (i) 1871 population-specific parasitism rates collected across Europe; (ii) 14 K cases of parasitism in the United Kingdom; and (iii) 16 K cases of parasitism in Germany, with data collected during the period 1735-2013. We find highly consistent effects of the different host species traits across our three datasets: the cuckoo prefers passerine host species of intermediate size that breed in grass- or shrubland and that feed their nestlings with insects, and avoids species that nest in cavities. Based on these results, we construct a novel host suitability index for all passerine species breeding in Europe, and show that host species known to have a corresponding cuckoo host race (gens) rank among the most suitable hosts in Europe. The distribution of our suitability index shows that host species cannot be classified as suitable or not but rather range within a continuum of suitability.
Topics: Animals; Birds; Ecosystem; Europe; Female; Host-Parasite Interactions; Parasites; Species Specificity; United Kingdom
PubMed: 29674671
DOI: 10.1038/s41598-018-24627-1 -
International Journal For Parasitology Jun 2005Cophylogenetic studies examine the relationship between host and parasite evolution. One aspect of cophylogenetic studies that has had little modern discussion is...
Cophylogenetic studies examine the relationship between host and parasite evolution. One aspect of cophylogenetic studies that has had little modern discussion is parasites with multiple definitive hosts. Parasite species with multiple host species are anomalous as, under a codivergence paradigm, speciation by the hosts should cause speciation of their parasites. We discuss situations such as cryptic parasite species, recent host switching or failure to speciate that may generate multi-host parasites. We suggest methods to identify which of the mechanisms have led to multi-host parasitism. Applying the suggested methods may allow multi-host parasites to be integrated more fully into cophylogenetic studies.
Topics: Animals; Classification; Ecosystem; Host-Parasite Interactions; Parasites; Parasitic Diseases; Phylogeny; Species Specificity
PubMed: 15885693
DOI: 10.1016/j.ijpara.2005.03.003 -
International Journal For Parasitology Dec 2013Anthropogenic habitat use is a major threat to biodiversity and is known to increase the abundance of generalist host species such as rodents, which are regarded as...
Anthropogenic habitat use is a major threat to biodiversity and is known to increase the abundance of generalist host species such as rodents, which are regarded as potential disease carriers. Parasites have an intimate relationship with their host and the surrounding environment and it is expected that habitat fragmentation will affect parasite infestation levels. We investigated the effect of habitat fragmentation on the ecto- and endoparasitic burdens of a broad niche small mammal, Rhabdomys pumilio, in the Western Cape Province, South Africa. Our aim was to look at the effects of fragmentation on different parasite species with diverse life history characteristics and to determine whether general patterns can be found. Sampling took place within pristine lowland (Fynbos/Renosterveld) areas and at fragmented sites surrounded and isolated by agricultural activities. All arthropod ectoparasites and available gastrointestinal endoparasites were identified. We used conditional autoregressive models to investigate the effects of habitat fragmentation on parasite species richness and abundance of all recovered parasites. Host density and body size were larger in the fragments. Combined ecto- as well as combined endoparasite taxa showed higher parasite species richness in fragmented sites. Parasite abundance was generally higher in the case of R. pumilio individuals in fragmented habitats but it appears that parasites that are more permanently associated with the host's body and those that are host-specific show the opposite trend. Parasite life history is an important factor that needs to be considered when predicting the effects of habitat fragmentation on parasite and pathogen transmission.
Topics: Animals; Biodiversity; Ecosystem; Murinae; Parasites; Parasitic Diseases; Rodent Diseases; South Africa
PubMed: 23954434
DOI: 10.1016/j.ijpara.2013.07.003 -
Acta Parasitologica Sep 2015The black grouper Mycteroperca bonaci is a commercially important fish off the coast of Yucatan, Mexico. To investigate possible differences between parasite communities...
The black grouper Mycteroperca bonaci is a commercially important fish off the coast of Yucatan, Mexico. To investigate possible differences between parasite communities in two different environments, 60 fish were collected from two areas during 2010 and 2011 and examined for parasites. The fish were classified into two age groups, in each of which the parameters of parasitic infection - prevalence, abundance and intensity - were determined. Parasite faunas were further described at the infracommunity level. Using both univariate (PERMANOVA) and multivariate statistical methods, the values of richness, abundance, diversity and Brillouin evenness as well as the Index values of Bray-Curtis and Jaccard for similarity were calculated and compared. The results of these tests and of CAP discriminant analyses at the two sites showed the existence of two distinct parasite communities. The parasite taxa mainly responsible for the differences were the digeneans Dollfustrema sp., Prosorhynchus spp., Lepidapedoides epinepheli and Hamacreadium mutabile, and the nematode Philometra salgadoi. The potential for some of these parasites to be used as biological tags for stock identification of M. bonaci is discussed.
Topics: Animals; Bass; Biota; Fish Diseases; Mexico; Parasite Load; Parasites; Parasitic Diseases, Animal; Prevalence
PubMed: 26204010
DOI: 10.1515/ap-2015-0067