U.S. flag

An official website of the United States government

IncA-C Alignment

    IncA/C plasmids are a class of plasmids from Enterobacteraciae that are relatively large (49 to >180 kbp), are readily transferred by conjugation, and carry multiple antimicrobial resistance genes. Reconstruction of the phylogeny of these plasmids has been difficult because of the high rate of remodeling by recombination-mediated horizontal gene transfer (HGT). We hypothesized that evaluation of nucleotide polymorphisms relative to the rate of HGT would help to develop a clock to show if anthropic practices have had significant influences on the lineages of the plasmid. A system was developed to rapidly sequence up to 191 known open27 reading-frames from each of 39 recently isolated IncA/C plasmids from a diverse panel of Salmonella enterica and Escherichia coli. With these data plus sequences from Genbank we were able to distinguish six distinct lineages that had extremely low numbers of polymorphisms within each lineage, especially among the largest group designated as Lineage 1. Two regions, each about half the plasmid in size, could be distinguished with a separate lineal pattern. The distribution of Lineage 1 showed that it has migrated extremely rapidly with fewer polymorphisms than can be expected in two-thousand years. Remodeling by frequent HGT was evident with a pattern that appeared to have the highest rate just upstream of the putative conjugation origin of transfer (ori-T). It seems likely that when an IncA/C plasmid is transferred also adjacent to a multiple antimicrobial resistance gene cassette.

    Data from: Draft genome sequences of eight streptogramin-resistant Enterococcus species isolates from animal and environmental sources in the United States

      Draft genome sequences of five *Enterococcus faecium*, two *Enterococcus hirae*, and one *Enterococcus gallinarum* from enviromental sources and chicken carcass rinsates. Isolates were selected for their resistance to the streptogramin antibiotic, Quinupristin-Dalfopristin and were all collected in the United States between 2001 and 2004. Antimicrobial resistance genes were identified conferring resistance to the macrolide-lincosamide-streptogramins, aminoglycosides, tetracycline, beta-lactams, and glycopeptides.


        myPhyloDB is an open-source software package aimed at developing a user-friendly web-interface for accessing and analyzing all of your laboratory's microbial ecology data (currently supported project types: soil, air, water, microbial, and human-associated). The storage and handling capabilities of myPhyloDB archives users' raw sequencing files, and allows for easy selection of any combination of projects/samples from all of your projects using the built-in SQL database. The data processing capabilities of myPhyloDB are also flexible enough to allow the upload, storage, and analysis of pre-processed data or raw (454 or Illumina) data files using the built-in versions of Mothur and R.

        GRACEnet Soil Biology Network

          The GRACEnet Soil Biology mission is to produce the soil biology data, including methods of identifying and quantifying specific organisms and processes they govern, that are needed to evaluate impacts on agroecosystems and sustainable agricultural practices.