TABLE 4.

Copper- and zinc-resistance genes identified in bacteria from livestock

Heavy metal	Heavy metal-resistance gene	Bacterial species	Animal origin	References
Copper	pcoA, pcoD	Salmonella enterica serovar MbandakaS. enterica serovar DerbyS. enterica serovar HeidelbergS. enterica serovar TyphimuriumS. enterica serovar WorthingtonS. enterica serovar RissenS. enterica serovar AgonaS. enterica serovar SenftenbergS. enterica serovar LondonS. enterica serovar OhioEscherichia coliHistophilius somni	Pigs, cattle, poultry	53, 146, 239–242
	copB	Staphylococcus aureus Staphylococcus epidermidis Staphylococcus haemolyticus Staphylococcus hominis Staphylococcus lentus Staphylococcus pasteuri Staphylococcus rostri Staphylococcus sciuri E. coli	Pigs, cattle, poultry	199, 240, 243
	cueO	E. coli	Poultry	240
	cusC	E. coli	Poultry	240
	mco	S. aureus	Pigs	243
Zinc	czrC	Mainly associated with methicillin-resistant staphylococci:S. aureusStaphylococcus hyicusStaphylococcus epidermidisS. haemolyticusS. hominisS. lentus	Pigs, cattle, poultry, meat from these animal species	51, 199–203, 244, 245
	czcD	S. TyphimuriumS. enterica serovar Infantis	Pigs	53
	zntA	E. coli	Poultry	240