Characterization of Large Plasmids Encoding Resistance to Toxic Heavy Metals in Salmonella abortus equi

• Published in: Biochemical and biophysical research communications Vol. 272; no. 1; pp. 6 - 11
• Main Authors: Ghosh, Anjali, Singh, Amarika, Ramteke, P.W., Singh, V.P.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 27-05-2000
• Subjects: Ampicillin Resistance - genetics; Animals; Bacterial Vaccines - genetics; Biotechnology; citrate utilization; curing; DNA; DNA, Bacterial - genetics; Drug Resistance, Microbial - genetics; Escherichia coli; Female; gene transfer; Genes, Bacterial; genetic transformation; heavy metal resistance; Horses; Male; Metals, Heavy - toxicity; Plasmids; pollutants; Salmonella; Salmonella - drug effects; Salmonella - genetics; Salmonella - pathogenicity; Salmonella abortus equi; total DNA; transformation; Transformation, Genetic; vaccines; heavy metal resistance; total DNA; transformation; curing; citrate utilization; Salmonella abortus equi
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.2000.2727

Salmonella abortus equi vaccine strains were found to be resistant to high levels of toxic heavy metals—arsenic, chromium, cadmium, and mercury. The two strains 157 and 158 were resistant to ampicillin also. Curing of these strains resulted in loss of one or more resistance marker indicating plasmid borne resistance. Plasmid profile of strain 157 showed presence of three plasmids of 85, 54, and 0.1 Kb, whereas 158 strain showed presence of 85 Kb and 2 Kb plasmids. Plasmids were isolated from strain 157 and introduced into E. coli DH5α with a transformation efficiency of 2 × 103 transformants/μg DNA. Interestingly the transformants were resistant to antibiotics, heavy metals (As, Cr, Cd, Hg) and was also able to utilize citrate, a trait specific to Salmonella species. We report and establish for the first time the transferable large plasmids encoding resistance to various heavy metals, antibiotics and biochemical nature of S. abortus equi.