Section 7
Chapter 6,133

Plasmid encoded transferable multiple antibiotic resistance in escherichia coli isolated from meat

Jayaratne, A.H.G.P.; Collins Thompson, D.L.; Trevors, J.T.

Systematic and Applied Microbiology 10(1): 78-84


ISSN/ISBN: 0723-2020
DOI: 10.1016/s0723-2020(87)80015-2
Accession: 006132419

Nine multiple antibiotic resistant Escherichia coli strains were isolated from commercially available meat. All isolates contained plasmids and were resistant to 7 or more antibiotics. Four isolates contained conjugal R-plasmids that transferred resistance to Escherichia coli K12 711. Two of the isolates also transferred R-plasmids to Salmonella typhimurium KS 294 and KS 296 recipients. Three E. coli isolates contained smaller mobilizable plasmids which were cotransferred along with the R-plasmid. Heat curing of R-plasmids confirmed they encoded for tetracycline, streptomycin, kanamycin and neomycin resistance. The frequencies of plasmid transfer were highest at 37.degree. C and declined with decreasing temperature. Two isolates displayed conjugal transfer of antibiotic resistance at 10.degree. C in broth. The highest transfer frequency occurred in the pH range 6.5 to 7.0. The influence of varying NaCl concentration on R-plasmid transfer also showed high variability among isolates from different sources. Conjugal transfer under anaerobic conditions was also highly variable among E. coli isolates from different sources.

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