These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Genetic variation in Brachyspira: chromosomal rearrangements and sequence drift distinguish B. pilosicoli from B. hyodysenteriae.
    Author: Zuerner RL, Stanton TB, Minion FC, Li C, Charon NW, Trott DJ, Hampson DJ.
    Journal: Anaerobe; 2004 Aug; 10(4):229-37. PubMed ID: 16701522.
    Abstract:
    Brachyspira pilosicoli and B. hyodysenteriae are anaerobic pathogenic intestinal spirochetes differing in host range and disease manifestations. Little is known about the size, organization, or genetic content of the B. pilosicoli genome and only limited information is available regarding the genetic organization in B. hyodysenteriae. Both B. hyodysenteriae and B. pilosicoli exist as recombinant populations, and this may be due, in part, to an unusual phage-like gene transfer agent, VSH-1. To compare genetic organization in these two species, the number of mapped loci on an existing physical and genetic map of B. hyodysenteriae B78(T) was expanded, and a combined physical and genetic map of B. pilosicoli P43/6/78(T) was constructed. The B. pilosicoli genome size was about 2.5 Mb, nearly 750 kb smaller than the B. hyodysenteriae genome. Several chromosomal rearrangements have contributed to differences in the size, organization, and content of the two bacterial genomes, and such differences may influence the ability of these species to infect different hosts and cause disease. To evaluate these differences further, comparisons were focused on genes thought to contribute to host-parasite interactions. Four genetic loci (bit, fruBC, vspA, and vspH) were found in B. hyodysenteriae, but not in B. pilosicoli, while two genetic loci (clpX and mglB) were found in B. pilosicoli, but not in B. hyodysenteriae. Contrary to a previous study, an intact copy of the hlyA gene, encoding the B. hyodysenteriae beta-hemolysin gene was detected in B. pilosicoli. Although the hlyA genes of these two species were nearly identical, sequence variation was detected in the intergenic region upstream of hlyA that may alter transcription and translation efficiency of this gene in B. pilosicoli. In addition, divergence in genes flanking hlyA may affect the chemical composition of lipid attached to the mature B. pilosicoli HlyA protein resulting in reduced hemolytic activity.
    [Abstract] [Full Text] [Related] [New Search]