The survival, replication, and virulence of mycoplasmas depend on their ability to capture and import host-derived nutrients using poorly characterized membrane proteins. Previous studies on the important bovine pathogen demonstrated that the amino-terminal end of an immunogenic 226-kDa (P226) protein, encoded by (the full-length product of which has a predicted molecular weight of 303 kDa), had lipase activity. The predicted sequence of MilA contains glycosaminoglycan binding motifs, as well as multiple copies of a domain of unknown function (DUF445) that is also found in apolipoproteins.
View Article and Find Full Text PDFThe Oxford Nanopore MinION DNA sequencing device can produce large amounts of long sequences, typically several kilobases, within a few hours. This long read capacity was exploited to detect antimicrobial resistance genes (ARGs) in a large veterinary teaching hospital environment, and to assess their taxonomic origin, genetic organisation and association with mobilisation markers concurrently. Samples were collected on eight occasions between November 2016 and May 2017 (inclusive) in a longitudinal study.
View Article and Find Full Text PDFgenomic island 1 (SGI1) is an integrative genetic island first described in serovars Typhimurium DT104 and Agona in 2000. Variants of it have since been described in multiple serovars of , as well as in , , , and several other genera. The island typically confers resistance to older, first-generation antimicrobials; however, some variants carry , , and genes that encode resistance to frontline, clinically important antibiotics, including third-generation cephalosporins.
View Article and Find Full Text PDFHorizontal Gene Transfer was long thought to be marginal in Mycoplasma a large group of wall-less bacteria often portrayed as minimal cells because of their reduced genomes (ca. 0.5 to 2.
View Article and Find Full Text PDFBacterial chondronecrosis and osteomyelitis (BCO) is increasingly recognized as a major cause of lameness in commercial broilers chickens worldwide, but the pathogenesis of the condition is incompletely understood. This was a longitudinal study of 20 commercial broiler farms in Victoria, Australia, to investigate the aetiology and pathology of BCO. Thorough postmortem examination was performed on culled and dead birds (n = 325) from 20 different flocks at either 1 week, 4 weeks or 5 weeks of age and samples were analysed by conventional bacteriology, molecular identification of infectious organisms detected, serology and histopathology.
View Article and Find Full Text PDFComparative genomics have revealed massive horizontal gene transfer (HGT) between Mycoplasma species sharing common ruminant hosts. Further results pointed toward an integrative conjugative element (ICE) as an important contributor of HGT in the small-ruminant-pathogen Mycoplasma agalactiae. To estimate the prevalence of ICEs in ruminant mycoplasmas, we surveyed their occurrence in a collection of 166 field strains representing 4 (sub)species that are recognized as major pathogens.
View Article and Find Full Text PDFUnlabelled: Horizontal gene transfer (HGT) is a main driving force of bacterial evolution and innovation. This phenomenon was long thought to be marginal in mycoplasmas, a large group of self-replicating bacteria characterized by minute genomes as a result of successive gene losses during evolution. Recent comparative genomic analyses challenged this paradigm, but the occurrence of chromosomal exchanges had never been formally addressed in mycoplasmas.
View Article and Find Full Text PDFHorizontal gene transfer (HGT) is a major force of microbial evolution but was long thought to be marginal in mycoplasmas. In silico detection of exchanged regions and of loci encoding putative Integrative Conjugative Elements (ICE) in several mycoplasma genomes challenged this view, raising the prospect of these simple bacteria being able to conjugate. Using the model pathogen Mycoplasma agalactiae, we demonstrated for the first time that one of these elements, ICEA, is indeed self-transmissible.
View Article and Find Full Text PDFComp Immunol Microbiol Infect Dis
September 2012
Mycoplasma agalactiae causes chronic infections in small ruminants and remains endemic in many regions of the world, despite intensive and costly eradication programs. In this study, the innate genomic plasticity of M. agalactiae was exploited to design and assess a combination of molecular epidemiological tools to trace the pathogen in different geographic locations and to understand its emergence or re-emergence after eradication campaigns.
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