Spontaneous emergence of an Hfr strain with a cit plasmid from natural isolates of citrate-positive Escherichia coli bovine origin.
AUTOR(ES)
Ishiguro, N
RESUMO
From citrate-utilizing (Cit+) Escherichia coli strain C53 of bovine origin, strains C53A and C53B were obtained. Upon mating with recA+ but not with recA mutant recipients of K-12, C53A produced chromosomal recombinants at quite high frequencies, leading to the following conclusions: (i) C53A is an Hfr strain; (ii) the site of integration of the Cit plasmid (IncH1) is between metA (89 min) and ara (1 min); (iii) the direction of chromosome transfer is clockwise; and (iv) the plasmid-associated determinants are transferred as the terminal markers. A transductant of a dnaA(Ts) strain, CRT46, which acquired Cit determinants from a recombinant, SG13, was also an Hfr strain similar to SG13, and thermoresistant due to suppressive integration. On the other hand, unstable C53B did not produce recombinants, but the frequency of RecA-independent transfer of the Cit plasmid was high, indicating that the Cit plasmid (IncH1) exists autonomously in C53B. Attempts to isolate an Hfr strain from C53B failed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=294427Documentos Relacionados
- Spontaneous Emergence of an Hfr Strain with a Cit Plasmid from Natural Isolates of Citrate-Positive Escherichia coli of Bovine Origin
- Spontaneous Emergence of an Hfr Strain with a Cit Plasmid from Natural Isolates of Citrate-Positive Escherichia coli of Bovine Origin
- Unclassified, citrate-positive member of the family Enterobacteriaceae resembling Escherichia coli.
- Isolation of citrate-positive variants of Escherichia coli from domestic pigeons, pigs, cattle, and horses.
- R plasmid with carbadox resistance from Escherichia coli of porcine origin.