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An Overview of Parasite Diversity
Published in Eric S. Loker, Bruce V. Hofkin, Parasitology, 2023
Eric S. Loker, Bruce V. Hofkin
First we introduce several terms that are applied to variant forms within a species. The term isolate describes a sample of a parasite species derived from a particular host at a particular time. Strain refers to an intraspecific group of parasites that differs from other such groups in one or more traits, including traits that might be relevant to control or treatment. Subspecies is used to identify a distinct group of organisms within a species that may occupy a particular region and that can interbreed with other subspecies. In this case, however, the organisms typically do not interbreed because of their isolation or some other reason. Subspecies are given a formal name, such as Trypanosoma brucei rhodesiense, with rhodesiense being the subspecies name. Also, although studies to discriminate among species use less variable genetic markers such as SSU rDNA or cytochrome oxidase, studies of intraspecific diversity rely on more variable markers, such as microsatellite markers or single nucleotide polymorphisms (SNPs, pronounced “snips).” See Figure 7.2 for further details. Both microsatellite markers and SNPs can be used to differentiate one individual parasite from another or to identify differences among populations of the same parasite species across small geographic scales.
Migration health theories: Healthy migrant effect and allostatic load. Can both be true?
Published in Bernadette N. Kumar, Esperanza Diaz, Migrant Health, 2019
Bernadette N. Kumar, Esperanza Diaz
Race is a concept traditionally used by biologists as a synonym for ‘subspecies’. These subspecies were meant to denote isolated populations of a species that contain individuals genetically more closely related to one another than to the rest of the species. Research on race has an inglorious history. Nineteenth century scientists ranked races according to biological and social worth (2). For example, measurements of the head were to gauge intelligence, and Northern Europeans ranked at the top. This kind of research justified slavery, imperialism, and anti-migration policies. Medical practitioners too contributed to racialized science by describing diseases such as drapetomania (irrational and pathological desire of slaves to run away) or explanations that coloured children weighed less due to physical degeneration (3).
An Overview of Parasite Diversity
Published in Eric S. Loker, Bruce V. Hofkin, Parasitology, 2015
Eric S. Loker, Bruce V. Hofkin
First we introduce several terms that are applied to variant forms within a species. The term isolate describes a sample of a parasite species derived from a particular host at a particular time. Strain refers to an intraspecific group of parasites that differs from other such groups in one or more traits, including traits that might be relevant to control or treatment. Subspecies is used to identify a distinctive group of organisms within a species that may occupy a particular region and that can interbreed with other subspecies. In this case, however, the organisms typically do not interbreed because of their isolation or another reason. Subspecies are given a formal name, such as Trypanosoma brucei rhodesiense, with rhodesiense being the subspecies name. Also, whereas studies to discriminate among species rely on less variable genetic markers such as SSU rDNA or cytochrome oxidase (see Section 2.3), studies of intraspecific diversity rely on more variable markers, such as other genes or sequences associated with the mitochondrial genome, or microsatellite markers. Microsatellite markers are short repeat sequences (usually 2 to 6 nucleotides long) that undergo rapid change in the number of times they are duplicated, providing a good way to discriminate among individual parasites.
Isoquinoline alkaloids isolated from Glaucium corniculatum var. corniculatum and Glaucium grandiflorum subsp. refractum var. torquatum with bioactivity studies
Published in Pharmaceutical Biology, 2023
Tuba Kusman Saygi, Nur Tan, Gülbahar Özge Alim Toraman, Caglayan Unsal Gurer, Osman Tugay, Gulacti Topcu
In the Flora of Turkey, the genus Glaucium is represented by 12 taxa, 7 of which are endemic. Glaucium grandiflorum Boiss.& Huet. has two varieties, var. grandiflorum Boiss.& Huet. and var. torquatum Cullen, the latter is an endemic species. Glaucium corniculatum (L.) Rud. is one of the biodiverse species with three subspecies; subsp. phoeniceum (Crantz) Holmboe, subsp. refractum (Nábelek) Cullen, subsp. tricolor (Besser) Holmboe and seven varieties; var. caricum (Stapf) Kuntze, var. corniculatum (L.) Rudolph, var. flavum (Crantz) Kuntze, var. fulvum (Sm.) Kuntze, var. grandiflorum (Boiss. & A.Huet) Kuntze, var. leiocarpum (Boiss.) Kuntze, var. pilosum Kuntze (Güner et al. 2012).
Lactic acid bacteria and bifidobacteria deliberately introduced into the agro-food chain do not significantly increase the antimicrobial resistance gene pool
Published in Gut Microbes, 2022
Vita Rozman, Petra Mohar Lorbeg, Primož Treven, Tomaž Accetto, Majda Golob, Irena Zdovc, Bojana Bogovič Matijašić
By analyzing pan-genomes, we identified core and accessory genes of 36 species. Despite the fact that strains of the subspecies B. animalis subsp. lactis are known to encode tetW,19 it is one of the most commonly used species in dietary supplements. A genomic island containing tetW and an adjacent transposase was confirmed in the majority of B. animalis subsp. lactis strains.20 The pan-genomes of the 38 B. animalis subsp. lactis and eight B. animalis subsp. animalis isolates comprised 3239 orthologous ORFs, of which 834 represented the core genome (Supplementary Figure S3A). Surprisingly, B. animalis subsp. lactis strains containing tetW showed close genomic relatedness as they clustered into a monophyletic clade. Notably, three B. animalis subsp. lactis isolates of animal origin were devoid of tetW (2010B, 2007B, and 2011B) and clustered into two separate branches, suggesting greater genomic distance. The results suggest that the genomic island was integrated into the common ancestor before the strain ATCC 27673 isolated from sewage diverged. This indicates a limited number of closely related strains circulating in the industry, but also the lack of sampling of this subspecies from other environments.
The ancestral stringent response potentiator, DksA has been adapted throughout Salmonella evolution to orchestrate the expression of metabolic, motility, and virulence pathways
Published in Gut Microbes, 2022
Helit Cohen, Boaz Adani, Emiliano Cohen, Bar Piscon, Shalhevet Azriel, Prerak Desai, Heike Bähre, Michael McClelland, Galia Rahav, Ohad Gal-Mor
The ubiquitous bacterial genus Salmonella is a facultative intracellular animal and human pathogen, belonging to the Proteobacteria phylum. The Salmonella genus comprises the two defined species Salmonella bongori (S. bongori) and Salmonella enterica (S. enterica). Salmonella diverged from a common ancestor with Escherichia coli about 100–160 million years ago.1,2 The two current species of Salmonella diverged from a common ancestor about 40 to 63 million years ago.1,3,4 One of these species, S. bongori, is frequently associated with infection of cold-blooded animals, like reptiles and amphibians. The other species, S. enterica, includes seven distinct subspecies. Among the S. enterica subspecies known, subspecies enterica (ssp. I) is associated with human and warm-blooded animal infections and responsible for 99% of all human salmonellosis infections.5