Details

Autor(en) / Beteiligte

• Parsons, Cameron
• Lee, Sangmi
• Jayeola, Victor
• Kathariou, Sophia
• Liu, Shuang-Jiang

Titel

Novel Cadmium Resistance Determinant in Listeria monocytogenes

Ist Teil von

• Applied and environmental microbiology, 2017-03, Vol.83 (5), p.E02580

Ort / Verlag

United States: American Society for Microbiology

Erscheinungsjahr

2017

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• is a foodborne pathogen that can cause severe disease (listeriosis) in susceptible individuals. It is ubiquitous in the environment and often exhibits resistance to heavy metals. One of the determinants that enables to tolerate exposure to cadmium is the efflux system, with CadA being a P-type ATPase. Three different genes (designated to ) were previously characterized in A novel putative cadmium resistance gene ( ) was recently identified through whole-genome sequencing, but experimental confirmation for its involvement in cadmium resistance is lacking. In this study, we characterized in strain F8027, a cadmium-resistant strain of serotype 4b. By screening a mariner-based transposon library of this strain, we identified a mutant with reduced tolerance to cadmium and that harbored a single transposon insertion in The tolerance to cadmium was restored by genetic complementation with the cadmium resistance cassette ( ), and enhanced cadmium tolerance was conferred to two unrelated cadmium-sensitive strains via heterologous complementation with Cadmium exposure induced expression, even at noninhibitory levels. Virulence assessments in the model suggested that a functional suppressed virulence, potentially promoting commensal colonization of the insect larvae. Biofilm assays suggested that inactivation reduced biofilm formation. These data not only confirm as a novel cadmium resistance determinant in but also provide evidence for roles in virulence and biofilm formation. is an intracellular foodborne pathogen causing the disease listeriosis, which is responsible for numerous hospitalizations and deaths every year. Among the adaptations that enable the survival of in the environment are the abilities to persist in biofilms, grow in the cold, and tolerate toxic compounds, such as heavy metals. Here, we characterized a novel determinant that was recently identified on a larger mobile genetic island through whole-genome sequencing. This gene ( ) was found to be responsible for cadmium detoxification and to be a divergent member of the Cad family of cadmium efflux pumps. Virulence assessments in a model suggested that may suppress virulence. Additionally, may be involved in the ability of to form biofilms. Beyond the role in cadmium detoxification, the involvement of in other cellular functions potentially explains its retention and wide distribution in .