Mycobacterium is a genus of bacteria with over a hundred non-pathogenic and pathogenic species, best recognized for certain members known to cause diseases such as tuberculosis and leprosy. Two novel protein families ...Mycobacterium is a genus of bacteria with over a hundred non-pathogenic and pathogenic species, best recognized for certain members known to cause diseases such as tuberculosis and leprosy. Two novel protein families important in the pathogenesis of Mycobacterium species are the PE and PPE families. These two protein families affect the antigenic profiles, disturbing host immunity. To better understand the origin and evolution of these gene families and the differences in their composition between pathogenic and non-pathogenic strains, several bioinformatic analyses were conducted both among Mycobacterium and closely related species that contain PE35 and PPE68 gene homologs. The methods included protein homology searches (BLASTP), horizontal gene transfer analysis (IslandViewer), phylogenetic analysis, gene cluster analysis and structural and functional constraints. Results revealed that PE and PPE gene homologs were not only limited to Mycobacterium, but also existed in three other non-mycobacterial genera, Rhodococcus, Tsukamurella and Segniliparus, and were possibly initially acquired from non-mycobacterial microorganisms by multiple horizontal gene transfers. Results also demonstrated that PE and PPE genes were more diverse and more rapidly evolving in pathogenic Mycobacterium as compared with non-pathogenic Mycobacterium and other non-mycobacterial species. These findings possibly shed light on the diverse functions and origins of the PE/PPE proteins among these organisms.展开更多
Metagenomics and bacterial culture were used to determine the normal skin microbiome of the Western mosquitofish (Gambusia affinis). This is the first study of G. affinis, and the most in-depth study of any fish skin,...Metagenomics and bacterial culture were used to determine the normal skin microbiome of the Western mosquitofish (Gambusia affinis). This is the first study of G. affinis, and the most in-depth study of any fish skin, utilizing a combination of 16S profile pyrosequencing and culture analysis. Over 1800 sequences obtained from three individuals reveal that over half of all sequences come from five invariant genera, Acinetobacter, Sphingomonas, Acidovorax, Enhydrobacter, and Aquabacterium. The microbiome is diverse but has low equitability, with a total of 81 genera detected. Challenge studies suggest that non-native bacteria cannot colonize the skin. This definition of the normal skin microbiome lays the foundation for future studies with this model system.展开更多
文摘Mycobacterium is a genus of bacteria with over a hundred non-pathogenic and pathogenic species, best recognized for certain members known to cause diseases such as tuberculosis and leprosy. Two novel protein families important in the pathogenesis of Mycobacterium species are the PE and PPE families. These two protein families affect the antigenic profiles, disturbing host immunity. To better understand the origin and evolution of these gene families and the differences in their composition between pathogenic and non-pathogenic strains, several bioinformatic analyses were conducted both among Mycobacterium and closely related species that contain PE35 and PPE68 gene homologs. The methods included protein homology searches (BLASTP), horizontal gene transfer analysis (IslandViewer), phylogenetic analysis, gene cluster analysis and structural and functional constraints. Results revealed that PE and PPE gene homologs were not only limited to Mycobacterium, but also existed in three other non-mycobacterial genera, Rhodococcus, Tsukamurella and Segniliparus, and were possibly initially acquired from non-mycobacterial microorganisms by multiple horizontal gene transfers. Results also demonstrated that PE and PPE genes were more diverse and more rapidly evolving in pathogenic Mycobacterium as compared with non-pathogenic Mycobacterium and other non-mycobacterial species. These findings possibly shed light on the diverse functions and origins of the PE/PPE proteins among these organisms.
文摘Metagenomics and bacterial culture were used to determine the normal skin microbiome of the Western mosquitofish (Gambusia affinis). This is the first study of G. affinis, and the most in-depth study of any fish skin, utilizing a combination of 16S profile pyrosequencing and culture analysis. Over 1800 sequences obtained from three individuals reveal that over half of all sequences come from five invariant genera, Acinetobacter, Sphingomonas, Acidovorax, Enhydrobacter, and Aquabacterium. The microbiome is diverse but has low equitability, with a total of 81 genera detected. Challenge studies suggest that non-native bacteria cannot colonize the skin. This definition of the normal skin microbiome lays the foundation for future studies with this model system.
