Correction: Ultrafast Evolution and Loss of CRISPRs Following a Host Shift in a Novel Wildlife Pathogen, Mycoplasma gallisepticum
Ontology highlight
ABSTRACT:
SUBMITTER:
PROVIDER: S-EPMC3293929 | biostudies-literature | 2012 Mar
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Measureable rates of genome evolution are well documented in human pathogens but are less well understood in bacterial pathogens in the wild, particularly during and after host switches. Mycoplasma gallisepticum (MG) is a pathogenic bacterium that has evolved predominantly in poultry and recently jumped to wild house finches (Carpodacus mexicanus), a common North American songbird. For the first time we characterize the genome and measure rates of genome evolution in House Finch isolates of MG, as well as in poultry outgroups. Using whole-genome sequences of 12 House Finch isolates across a 13-year serial sample and an additional four newly sequenced poultry strains, we estimate a nucleotide diversity in House Finch isolates of only ∼2% of ancestral poultry strains and a nucleotide substitution rate of 0.8-1.2×10(-5) per site per year both in poultry and in House Finches, an exceptionally fast rate rivaling some of the highest estimates reported thus far for bacteria. We also found high diversity and complete turnover of CRISPR arrays in poultry MG strains prior to the switch to the House Finch host, but after the invasion of House Finches there is progressive loss of CRISPR repeat diversity, and recruitment of novel CRISPR repeats ceases. Recent (2007) House Finch MG strains retain only ∼50% of the CRISPR repertoire founding (1994-95) strains and have lost the CRISPR-associated genes required for CRISPR function. Our results suggest that genome evolution in bacterial pathogens of wild birds can be extremely rapid and in this case is accompanied by apparent functional loss of CRISPRs.
| S-EPMC3276549 | biostudies-literature
Project description:Respiratory pathogens are a health threat for poultry. Co-infections lead to the exacerbation of clinical symptoms and lesions. Mycoplasma gallisepticum (M. gallispeticum) and Avian Metapneumovirus (AMPV) are two avian respiratory pathogens that co-circulate worldwide. The knowledge about the host-pathogen interaction of M. gallispeticum and AMPV in the chicken respiratory tract is limited. We aimed to investigate how co-infections affect the pathogenesis of the respiratory disease and whether the order of invading pathogens leads to changes in host-pathogen interaction. We used chicken tracheal organ cultures (TOC) to investigate pathogen invasion and replication, lesion development, and selected innate immune responses, such as interferon (IFN) α, inducible nitric oxide synthase (iNOS) and IFNλ mRNA expression levels. We performed mono-inoculations (AMPV or M. gallispeticum) or dual-inoculations in two orders with a 24-h interval between the first and second pathogen. Dual-inoculations compared to mono-inoculations resulted in more severe host reactions. Pre-infection with AMPV followed by M. gallispeticum resulted in prolonged viral replication, more significant innate immune responses, and lesions (p < 0.05). AMPV as the secondary pathogen impaired the bacterial attachment process. Consequently, the M. gallispeticum replication was delayed, the innate immune response was less pronounced, and lesions appeared later. Our results suggest a competing process in co-infections and offer new insights in disease processes.
| S-EPMC8618481 | biostudies-literature
Project description:Mycoplasma gallisepticum transcriptome comparison between in vitro grown cultures of strains Rlow and F utilizing oligo DNA microarrays.
2010-01-07 | GSE19755 | GEO
Project description:Emerging infectious diseases often result from pathogens jumping to novel hosts. Identifying possibilities and constraints on host transfer is therefore an important facet of research in disease ecology. Host transfers can be studied for the bacterium Mycoplasma gallisepticum, predominantly a pathogen of poultry until its 1994 appearance and subsequent epidemic spread in a wild songbird, the house finch Haemorhous mexicanus and some other wild birds. We screened a broad range of potential host species for evidence of infection by M. gallisepticum in order to answer 3 questions: (1) is there a host phylogenetic constraint on the likelihood of host infection (house finches compared to other bird species); (2) does opportunity for close proximity (visiting bird feeders) increase the likelihood of a potential host being infected; and (3) is there seasonal variation in opportunity for host jumping (winter resident versus summer resident species). We tested for pathogen exposure both by using PCR to test for the presence of M. gallisepticum DNA and by rapid plate agglutination to test for the presence of antibodies. We examined 1,941 individual birds of 53 species from 19 avian families. In 27 species (15 families) there was evidence for exposure with M. gallisepticum although conjunctivitis was very rare in non-finches. There was no difference in detection rate between summer and winter residents, nor between feeder birds and species that do not come to feeders. Evidence of M. gallisepticum infection was found in all species for which at least 20 individuals had been sampled. Combining the present results with those of previous studies shows that a diverse range of wild bird species may carry or have been exposed to M. gallisepticum in the USA as well as in Europe and Asia.
| S-EPMC4111589 | biostudies-literature
Project description:BACKGROUND: DNA repair is essential for the maintenance of genome stability in all living beings. Genome size as well as the repertoire and abundance of DNA repair components may vary among prokaryotic species. The bacteria of the Mollicutes class feature a small genome size, absence of a cell wall, and a parasitic lifestyle. A small number of genes make Mollicutes a good model for a "minimal cell" concept. RESULTS: In this work we studied the DNA repair system of Mycoplasma gallisepticum on genomic, transcriptional, and proteomic levels. We detected 18 out of 22 members of the DNA repair system on a protein level. We found that abundance of the respective mRNAs is less than one per cell. We studied transcriptional response of DNA repair genes of M. gallisepticum at stress conditions including heat, osmotic, peroxide stresses, tetracycline and ciprofloxacin treatment, stationary phase and heat stress in stationary phase. CONCLUSIONS: Based on comparative genomic study, we determined that the DNA repair system M. gallisepticum includes a sufficient set of proteins to provide a cell with functional nucleotide and base excision repair and mismatch repair. We identified SOS-response in M. gallisepticum on ciprofloxacin, which is a known SOS-inducer, tetracycline and heat stress in the absence of established regulators. Heat stress was found to be the strongest SOS-inducer. We found that upon transition to stationary phase of culture growth transcription of DNA repair genes decreases dramatically. Heat stress does not induce SOS-response in a stationary phase.
| S-EPMC4007778 | biostudies-literature
Project description:The epigenetics of bacteria, and bacteria with a reduced genome in particular, is of great interest, but is still poorly understood. Mycoplasma gallisepticum, a representative of the class Mollicutes, is an excellent model of a minimal cell because of its reduced genome size, lack of a cell wall, and primitive cell organization. In this study we investigated DNA modifications of the model object Mycoplasma gallisepticum and their roles. We identified DNA modifications and methylation motifs in M. gallisepticum S6 at the genome level using single molecule real time (SMRT) sequencing. Only the ANCNNNNCCT methylation motif was found in the M. gallisepticum S6 genome. The studied bacteria have one functional system for DNA modifications, the Type I restriction-modification (RM) system, MgaS6I. We characterized its activity, affinity, protection and epigenetic functions. We demonstrated the protective effects of this RM system. A common epigenetic signal for bacteria is the m6A modification we found, which can cause changes in DNA-protein interactions and affect the cell phenotype. Native methylation sites are underrepresented in promoter regions and located only near the -35 box of the promoter, which does not have a significant effect on gene expression in mycoplasmas. To study the epigenetics effect of m6A for genome-reduced bacteria, we constructed a series of M. gallisepticum strains expressing EGFP under promoters with the methylation motifs in their different elements. We demonstrated that m6A modifications of the promoter located only in the -10-box affected gene expression and downregulated the expression of the corresponding gene.
| S-EPMC9681074 | biostudies-literature
Project description:Mycoplasma gallisepticum transcriptome comparison between in vitro grown cultures of strains Rlow and F utilizing oligo DNA microarrays. Two-condition experiment, Rlow vs. F strain cells. Biological replicates: 3. 1 technical replicate per biological replicate which includes a dye swap.
2010-04-22 | E-GEOD-19755 | biostudies-arrayexpress
Project description:Mycoplasmas are small bacterial commensals or pathogens that commonly colonize host mucosal tissues and avoid rapid clearance, in part by stimulating inflammatory, immunopathogenic responses. We previously characterized a wide array of transcriptomic perturbations in avian host tracheal mucosae infected with virulent, immunopathologic Mycoplasma gallisepticum; however, mechanisms delineating these from protective responses, such as those induced upon vaccination, have not been thoroughly explored. In this study, host transcriptomic responses to two experimental M. gallisepticum vaccines were assessed during the first 2 days of infection. Relative to virulent infection, host metabolic and immune gene responses to both vaccines were greatly decreased, including early innate immune responses critical to disease development and subsequent adaptive immunity. These data specify host genes and potential mechanisms contributing to maladaptive versus beneficial host responses-information critical for design of vaccines efficacious in both limiting inflammation and enabling pathogen clearance.
| S-EPMC6386537 | biostudies-literature
Project description:Mycoplasma gallisepticum is a convenient model object for studying the regulation of transcription because it has a reduced genome, lack of cell wall and many metabolic pathways, and also easy to culture and non-pathogenic to humans. For rapid investigation of gene expression we developed microarray design including 3 366 probes for 678 genes. They included 665 protein coding sequences and 13 antisense RNAs from 816 genes and 17 ncRNAs present in Mycoplasma gallisepticum. This work was carried out transcriptomic profiling for different types of effects on the expression of genes of Mycoplasma gallisepticum: 1) genetic knock-out mutants; 2) cell culture exposed to sublethal concentrations of antibiotics; and 3) well-characterized heat stress effect. The study was performed on Agilent one-color microarray with custom design and random-T7 polymerase primer for cDNA synthesis. Using set of different probes for each gene or ncRNA allows to increase accuracy of gene expression quality.
2016-08-18 | GSE85777 | GEO
Project description:The study was to explore the rational use of danofloxacin against Mycoplasma gallisepticum (MG) based on its clinical breakpoint (CBP) and the effect on lung microbiota. The CBP was established according to epidemiological cutoff value (ECV/COWT), pharmacokinetic-pharmacodynamic (PK-PD) cutoff value (COPD) and clinical cutoff value (COCL). The ECV was determined by the micro-broth dilution method and analyzed by ECOFFinder software. The COPD was determined according to PK-PD modeling of danofloxacin in infected lung tissue with Monte Carlo analysis. The COCL was performed based on the relationship between the minimum inhibitory concentration (MIC) and the possibility of cure (POC) from clinical trials. The CBP in infected lung tissue was 1 μg/mL according to CLSI M37-A3 decision tree. The 16S ribosomal RNA (rRNA) sequencing results showed that the lung microbiota, especially the phyla Firmicutes and Proteobacteria had changed significantly along with the process of cure regimen (the 24 h dosing interval of 16.60 mg/kg b.w for three consecutive days). Our study suggested that the rational use of danofloxacin for the treatment of MG infections should consider the MIC and effect of antibiotics on the respiratory microbiota.
| S-EPMC8944443 | biostudies-literature