An Overview of Parasite Diversity
Eric S. Loker, Bruce V. Hofkin in Parasitology, 2023
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.
An Overview of Parasite Diversity
Eric S. Loker, Bruce V. Hofkin in Parasitology, 2015
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.
Gateways of Pathogenic Bacterial Entry into Host Cells—Salmonella
K. Balamurugan, U. Prithika in Pocket Guide to Bacterial Infections, 2019
Salmonella, a gram-negative, rod-shaped, facultative anaerobic, nonsporing bacteria, belongs to the member of Enterobacteriaceae family, causing gastrointestinal (GI) disorders and multisystemic fatal infections. Initially the genus Salmonella consists of two species namely S. bongori and S. enterica (Porwollik et al. 2004). S. enterica, the enteric pathogen, is further classified with six subspecies (S. enterica subsp. enterica, S. enterica subsp. salamae, S. enterica subsp. arizonae, S. enterica subsp. diarizonae, S. enterica subsp. indica, and S. enterica subsp. houtenae) and more than 2600 serovers (Porwollik et al. 2004; Guibourdenche et al. 2010). Salmonella pathogens can survive in the GI tract of various animals including human and birds. However, the enteric fever causing Salmonella serotypes and the disease-causing pathogens spread from asymptomatic human carriers via feces and contaminated food and water. Based on agglutination properties of their outer membrane protein antigens such as somatic O, flagellar H and capsular Vi, they are commonly classified (Guibourdenche et al. 2010). Most of the Salmonella human infections are due to strains of Salmonella enterica subsp. enterica. Now its nomenclature is established on the basis of serotypes name belonging to subspecies. In case of Salmonella enterica subsp. Enterica serotype Typhimurium is edited to Salmonella Typhimurium (Brenner et al. 2000).
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.
Lead induces Siberian tiger fibroblast apoptosis by interfering with intracellular homeostasis
Published in Drug and Chemical Toxicology, 2018
Zheng Liu, Hui Wang, Wenxiu Zhang, Ziao Yuan, Hongyi Yuan, Xueting Liu, Minghai Zhang, Xuesong Guo, Weijun Guan
The Siberian tiger, the largest tiger subspecies, has a reputation of being the king of the forest in the world. Currently, the wild population is mainly distributed in northeast China, Russian Far East, and northern Korea (Matyushkin et al.1999). In China, the Siberian tiger is widely distributed in the forest of northeastern region. However, because of poaching and environmental deterioration, there has been a sharp drop in the number of the wild populations. The distribution has gradually reduced, thus making it one of the world’s most endangered big cat. Habitat destruction is the main reason for its decline and distribution reduction (Miquelle and Pikunov 2003). Heavy metal accumulation and pollution in the forest ecosystems has not only destroyed the tiger habitats but also destroyed the tiger’s food sources such as hoofed animals, roe deer, wild boar, and red deer (Russello et al.2004). With the rapid development of modern industries, agriculture, and transportation, the tiger habitat is under serious threat, especially in areas with heavy metal pollution. This has led to a significant impact on the Siberian tiger’s growth, development, and disease incidence.
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).
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