Table 1. Other nonmedical uses of antibiotics with evidence of or potential transfer of resistant bacteria or genes to humans and impact.

Use	Evidence	Potential or actual impact	Alternative to antibiotic use?
Bee-keeping
Oxytetracycline to treat or prevent foulbrood, bacterial infections of bee larvae that can destroy entire bee colonies.	Increased MICs of oxytetracycline in bacteria isolated from bees in countries using these control measures [36].	Transmissible resistance genes in bee-infecting bacteria have also been found in bacteria isolated from humans and foodstuffs (e.g., cheese, meats). Resistance genes may spread via intermediate organisms [37].	In the EU, infected hives are generally sterilized and burned, reducing unnecessary use of antibiotics.
	Honeybees do not metabolise antibiotics, which may therefore be present at surprisingly high levels in honey [38].	Could lead to the inadvertent consumption of antibiotics by people and generate subtherapeutic levels of antibiotics in the human gut, which could select resistant bacteria.
Horticulture
Streptomycin, for example, was long used to treat fire blight, infection with Erwinia amylovora affecting apple and pear orchards.	Streptomycin-resistant Erwinia common in the US, also in Israel and New Zealand [39]. Evidence for gene transfer between Erwinia and animal pathogens, with a distinct genetic element found in Erwinia and in a pig-infecting strain of E.coli [40]. This genetic insert has also been found in the human pathogen Campylobacter jejuni, which can also infect pigs [41].	To avoid the potential for environmental contamination, the US Environmental Protection Agency banned the import of plant agricultural produce treated with gentamicin from Latin America.	None
Food preservation
Bacteriocins (nisin) added to dairy products and canned food to inhibit growth of pathogens such as Listeria monocytogenes	L. monocytogenes can develop resistance to bacteriocins, possibly due to changes in its cell surface [42].	Some interest in the medical use of bacteriocins. However, there is no reason to assume that clinical use would not select for resistant strains.	None
Ethanol production
To prevent bacterial contamination during the fermentation process.	The grains produced in ethanol production form a nourishing feed known as “dried distillers” grains with soluble (DDGS), which are fed to farm animals.	Although it has been claimed that antibiotics are rendered inactive by distilling practices, a 2008 FDA report [43] found evidence for antibiotics in DDGS.	None
Prevent barnacle build-up on boat hulls
Tetracycline to prevent build-up of bacterial biofilms to which larger organisms such as barnacles attach.	Tetracycline antibiotics in antifouling paint [44].	Use of tetracycline in aquatic ecosystems has the potential to select for antibiotic-resistant biofilm-causing bacteria.	None