Tsitsos Anestis, Peratikos Pantelis, Damianos Alexandros, Kyritsi Maria A, Arsenos Georgios, Hadjichristodoulou Christos, Soultos Nikolaos, Gousia Panagiota, Economou Vangelis
Laboratory of Animal Food Products Hygiene-Veterinary Public Health, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece.
Laboratory of Hygiene and Epidemiology, Faculty of Medicine, University of Thessaly, 41222, Larissa, Greece.
Food Microbiol. 2025 Aug;129:104745. doi: 10.1016/j.fm.2025.104745. Epub 2025 Feb 6.
Listeria monocytogenes, the leading cause of fatalities among foodborne pathogens, exhibits remarkable resilience in food industry environments. This study aims to isolate and characterize L. monocytogenes strains along the beef production chain of a vertically integrated industry. Sampling included carcass, hide, and environmental samples collected from a cattle unit and partner slaughterhouse. The samples were examined for the presence of Listeria monocytogenes. The isolates were characterized via molecular serotyping and MALDI-TOF proteomic analysis. Further analyses included antimicrobial susceptibility testing, biofilm formation assessment, and virulence gene investigation. A total of 24 L. monocytogenes strains were isolated. The prevalence in carcasses, hide and slaughterhouse environment was 21.7%, 6.7% and 8.8% respectively. Molecular serogroup IIc predominated, followed by serogroups IIa, IIb, and IVb. Almost all strains showed a moderate or strong ability to produce biofilms and resistance to at least one antimicrobial, with clindamycin, vancomycin, and tetracycline demonstrating the highest rates of resistance. Three strains were also characterized as multidrug-resistant, while all strains possessed at least six virulence genes. The proteomic analysis organized the isolated strains in three clusters, whereas the transmission pathways primarily implicated carcass washing water and hides. Understanding L.monocytogenes dissemination along the beef production chain is vital for preventing transmission to humans and emergence of a listeriosis outbreak.
单核细胞增生李斯特菌是食源性病原体中导致死亡的主要原因，在食品工业环境中具有很强的生存能力。本研究旨在分离和鉴定垂直一体化产业牛肉生产链中的单核细胞增生李斯特菌菌株。采样包括从养牛场和合作屠宰场采集的胴体、牛皮和环境样本。检测样本中是否存在单核细胞增生李斯特菌。通过分子血清分型和基质辅助激光解吸电离飞行时间质谱（MALDI-TOF）蛋白质组学分析对分离株进行鉴定。进一步的分析包括抗菌药物敏感性测试、生物膜形成评估和毒力基因研究。共分离出24株单核细胞增生李斯特菌菌株。胴体、牛皮和屠宰场环境中的患病率分别为21.7%﹑6.7%和8.8%。分子血清群IIc占主导地位，其次是血清群IIa、IIb和IVb。几乎所有菌株都表现出中等或较强的生物膜形成能力以及对至少一种抗菌药物的耐药性，其中克林霉素、万古霉素和四环素的耐药率最高。三株菌株还被鉴定为多重耐药，而所有菌株都至少拥有六个毒力基因。蛋白质组学分析将分离出的菌株分为三个簇，而传播途径主要涉及胴体冲洗水和牛皮。了解单核细胞增生李斯特菌在牛肉生产链中的传播情况对于预防其传播给人类和爆发李斯特菌病至关重要。
