Detection of premature stop codons leading to truncated internalin A among food and clinical strains of Listeria monocytogenes.

摘要: Listeria monocytogenes is a food-borne pathogen responsible for outbreaks and sporadic cases of listeriosis, severe invasive disease. Internalin A (InlA) protein encoded by inlA has key role in the mechanism pathogenesis L. infection, specifically invasion human intestinal epithelial cells. Studies on have shown that mutations leading to premature stop codons (PMSCs) occur naturally are associated with impaired virulence strains. Increasing evidence suggests PMSCs frequent strains from foods, but rare among clinical isolates. In this study, 22 collected Portugal processing environment bakery industry (n = 1), different food products 10) 11) were analysed efficiency Caco-2 Sequencing revealed previously reported types three one strain presenting molecular serotypes (i.e., IIa, IIb IIc). The remaining 18 isolates did not show inlA. four presented lower invasiveness efficiencies cells (below 8.9%) when compared control (full-length InlA). addition, isolate showed reduced no This increased transcript levels obtained laboratory strain. Our data support hypothesis isolated attenuated due presence PMSCs. information would be critically needed adequate risk-assessments foodborne illness burden