title: Comparative analyses of two cryptic plasmids from Haemophilus somnus (Histophilus somni).
abstract: Haemophilus somnus is an opportunistic bacterial pathogen capable of causing pneumonia, septicemia, and other systemic infections in bovines. An H. somnus isolate from bovine abortion (strain 649) was found to carry a approximately 1.3 kb plasmid (pHS649) that contained partial homology to two previously sequenced Haemophilus/Histophilus plasmids by BLAST analyses. Sequence analysis of pHS649 identified a putative RepA protein with 48% similarity to the RepA protein of Escherichia coli plasmid pKL1. A approximately 5 kb plasmid (pHS129) from H. somnus preputial isolate 129Pt was also sequenced and found to encode two copies of a putative RepB protein. Whereas pHS649 stably replicated in E. coli DH5alpha, pHS129 did not. Genetic relatedness and possible replication mechanisms of these plasmids are described.
authors.affiliation: Center for Molecular Medicine and Infectious Diseases, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
authors.forename: Shivakumara
authors.initials: S
authors.lastname: Siddaramappa
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Duncan
authors.forename: Thomas
authors.initials: T
authors.lastname: Brettin
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Inzana
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002417:Cattle; D004261:DNA Replication; D004269:DNA, Bacterial / Q000235:genetics; D005260:Female; D006192:Haemophilus Infections / Q000382:microbiology / Q000662:veterinary*; D044138:Haemophilus somnus / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics*; D011247:Pregnancy; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial