Genetic Carriers and Genomic Distribution of cadA6—A Novel Variant of a Cadmium Resistance Determinant Identified in Listeria spp

International Journal of Molecular Sciences

Martyna Krupińska¹  Cora Chmielowska¹  Dariusz Bartosik¹  Kinga Lipka¹  Barbara Szmulkowska¹  Dorota Korsak²  Alicja Krop² 

[1] Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland;Department of Molecular Microbiology, Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland;

关键词: Listeria;    Listeria ivanovii;    Listeria seeligeri;    Listeria monocytogenes;    heavy-metal resistance;    cadmium;   

DOI  :  10.3390/ijms21228713

来源: DOAJ

【 摘 要 】

Listeria monocytogenes is a pathogen responsible for severe cases of food poisoning. Listeria spp. strains occurring in soil and water environments may serve as a reservoir of resistance determinants for pathogenic L. monocytogenes strains. A large collection of Listeria spp. strains (155) isolated from natural, agricultural, and urban areas was screened for resistance to heavy metals and metalloids, and the presence of resistance determinants and extrachromosomal replicons. Of the tested strains, 35% were resistant to cadmium and 17% to arsenic. Sequence analysis of resistance plasmids isolated from strains of Listeria seeligeri and Listeria ivanovii, and the chromosome of L. seeligeri strain Sr73, identified a novel variant of the cadAC cadmium resistance efflux system, cadA6, that was functional in L. monocytogenes cells. The cadA6 cassette was detected in four Listeria species, including strains of L. monocytogenes, isolated from various countries and sources—environmental, food-associated, and clinical samples. This resistance cassette is harbored by four novel composite or non-composite transposons, which increases its potential for horizontal transmission. Since some cadAC cassettes may influence virulence and biofilm formation, it is important to monitor their presence in Listeria spp. strains inhabiting different environments.

【 授权许可】

Unknown