Applied and Environmental Microbiology, January 2010, p. 627-630, Vol. 76, No. 2

Diverse Cadmium Resistance Determinants in Listeria monocytogenes Isolates from the Turkey Processing Plant Environment

Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina 27695

Received 23 July 2009/ Accepted 15 November 2009

Two different cadA cadmium resistance determinants (cadA1, first identified in Tn5422, andcadA2, associated with pLM80) were detected among cadmium-resistant Listeria monocytogenes strains from turkey processing plants. Prevalence of cadA1 versus cadA2 was serotype associated. Cadmium-resistant isolates that were also resistant to benzalkonium chloride (BC) were more likely to harbor cadA2 alone or together with cadA1 than isolates that were cadmium resistant but BC susceptible.