Listeria ssp. in beef carpaccio and resistance profile to antimicrobial agents

The present study was conducted to verify the occurrence of Listeria spp. in 50 samples of beef carpaccio sold in bars and restaurants; and to evaluate the resistance profile to antimicrobial agents used in the routine treatment of infections. It was found that 20% of samples from restaurants and 35% from bars were contaminated with Listeria spp. Among the species, L. welshimeri was most frequently isolated (81.82%), followed by L. grayi, (13.66%) and L. monocytogenes(4.55%). The Oxford agar plating medium was the most efficient. The resistant behavior occurred to all antimicrobial agents tested, except tetracycline, to which 95.5% of the strains were sensitive. Multidrug resistance was observed in 68.75% of the strains analyzed. Thus, it is concluded that the consumption of beef carpaccio represents a potential risk, and a serious public health problem, especially due to the confirmation of pathogenic strains that are resistant to major antimicrobial agents used in the treatment of listeriosis.

本研究旨在验证酒吧与餐厅在售的50份卡巴乔牛肉片（beef carpaccio）样本中是否存在李斯特菌属（Listeria spp.），并评估分离株对感染常规治疗所用抗菌剂的耐药谱。结果显示，餐厅样本的李斯特菌属污染率为20%，酒吧样本污染率达35%。在分离得到的菌种中，韦氏李斯特菌（L. welshimeri）检出率最高，占比81.82%，其次为格氏李斯特菌（L. grayi，13.66%）与单核细胞增生李斯特菌（L. monocytogenes，4.55%）。牛津琼脂平板培养基（Oxford agar plating medium）的分离效果最优。受试菌株对除四环素外的所有抗菌剂均表现出耐药性，95.5%的菌株对四环素敏感。经分析，68.75%的受试菌株呈现多重耐药性。综上，食用卡巴乔牛肉片存在潜在食源性风险，可构成严重的公共卫生问题，尤其是本次研究确认了对治疗李斯特菌病的主流抗菌剂具有耐药性的致病性菌株。