Kerek Ádám, Németh Virág, Szabó Ábel, Papp Márton, Bányai Krisztián, Kardos Gábor, Kaszab Eszter, Bali Krisztina, Nagy Zoltán, Süth Miklós, Jerzsele Ákos
Department of Pharmacology and Toxicology, University of Veterinary Medicine, István utca 2, H-1078 Budapest, Hungary.
National Laboratory of Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, University of Veterinary Medicine Budapest, István utca 2, H-1078 Budapest, Hungary.
Vet Sci. 2024 Jun 8;11(6):265. doi: 10.3390/vetsci11060265.
Raw milk and dairy products can serve as potential vectors for transmissible bacterial, viral and protozoal diseases, alongside harboring antimicrobial-resistance genes. This study monitors the changes in the antimicrobial-resistance gene pool in raw milk and cheese, from farm to consumer, utilizing next-generation sequencing. Five parallel sampling runs were conducted to assess the resistance gene pool, as well as phage or plasmid carriage and potential mobility. In terms of taxonomic composition, in raw milk the Firmicutes phylum made up 41%, while the Proteobacteria phylum accounted for 58%. In fresh cheese, this ratio shifted to 93% Firmicutes and 7% Proteobacteria. In matured cheese, the composition was 79% Firmicutes and 21% Proteobacteria. In total, 112 antimicrobial-resistance genes were identified. While a notable reduction in the resistance gene pool was observed in the freshly made raw cheese compared to the raw milk samples, a significant growth in the resistance gene pool occurred after one month of maturation, surpassing the initial gene frequency. Notably, the presence of extended-spectrum beta-lactamase (ESBL) genes, such as (100% coverage, 99.3% identity) and (97.1% coverage, 96.2% identity), raised concerns; these genes have a major public health relevance. In total, nineteen such genes belonging to nine gene families (, , , , , , , , ) have been identified. The largest number of resistance genes were identified against fluoroquinolone drugs, which determined efflux pumps predominantly. Our findings underscore the importance of monitoring gene pool variations throughout the product pathway and the potential for horizontal gene transfer in raw products. We advocate the adoption of a new approach to food safety investigations, incorporating next-generation sequencing techniques.
生乳和乳制品可能是可传播细菌、病毒和原生动物疾病的潜在载体，同时还携带抗微生物耐药基因。本研究利用下一代测序技术监测生乳和奶酪从农场到消费者整个过程中抗微生物耐药基因库的变化。进行了五次平行采样，以评估耐药基因库以及噬菌体或质粒携带情况和潜在迁移率。在分类组成方面，生乳中厚壁菌门占41%，而变形菌门占58%。在新鲜奶酪中，这一比例变为厚壁菌门占93%，变形菌门占7%。在成熟奶酪中，组成是厚壁菌门占79%，变形菌门占21%。总共鉴定出112个抗微生物耐药基因。与生乳样本相比，新鲜制作的生奶酪中耐药基因库显著减少，但成熟一个月后耐药基因库显著增加，超过了初始基因频率。值得注意的是，超广谱β-内酰胺酶（ESBL）基因的存在引发了担忧，如（100%覆盖率，99.3%同一性）和（97.1%覆盖率，96.2%同一性）；这些基因具有重大的公共卫生意义。总共已鉴定出属于九个基因家族（、、、、、、、、）的19个此类基因。鉴定出的针对氟喹诺酮类药物的耐药基因数量最多，主要决定了外排泵。我们的研究结果强调了在整个产品生产过程中监测基因库变化的重要性以及原料产品中水平基因转移的可能性。我们主张采用一种新的食品安全调查方法，纳入下一代测序技术。
