title: Resistance to various antibiotics of Salmonella and Escherichia coli isolated from registrable farm feeds.
abstract: Resistance to 20 antibiotics of 128 Salmonella and 97 Escherichia coli isolates from various registrable farm feeds was determined. A high frequency of comparatively low levels of resistance was found in both the Salmonella and E. coli isolates. This, together with an elevated frequency of multiple resistance, indicates that problems related to an effective transfer in bacterial populations of resistance to certain antibiotics are a distinct possibility. The addition of antibiotics, such as penicillin and tetracyclines, to animal feeds can create conditions for rapid selection amongst bacteria resistant to antibiotics. The numbers of resistant bacteria in the animal environment may be increased and may lead to the development of veterinary and human health problems from the possible transfer of antimicrobial resistance from animal pathogens to human pathogens or spreading in the human population of animal pathogens resistant to antibiotics. There is a need for caution in the use of antibiotics, particularly in animal feeds. Extended survey of, and epidemiological research on, farm feeds, manufacturing mills and animal production units are emphasized.
authors.forename: A M
authors.initials: AM
authors.lastname: Durand
authors.forename: M L
authors.initials: ML
authors.lastname: Barnard
authors.forename: M L
authors.initials: ML
authors.lastname: Swanepoel
authors.forename: M M
authors.initials: MM
authors.lastname: Engelbrecht
mesh_terms: D000821:Animal Feed; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification; D012475:Salmonella / Q000187:drug effects* / Q000302:isolation & purification; D013019:South Africa
chemical_list: D000900:Anti-Bacterial Agents