Leroy Sabine, Christieans Souad, Talon Régine
Université Clermont Auvergne, INRA, MEDiS, Clermont-Ferrand, France.
ADIV, ZAC des Gravanches, Clermont-Ferrand, France.
Front Microbiol. 2019 Mar 6;10:392. doi: 10.3389/fmicb.2019.00392. eCollection 2019.
The presence of determinants of resistance to antibiotics can constitute a possible safety hazard in coagulase-negative staphylococci (CNS), which are widely present in food of animal origin. Among CNS, is a species frequently isolated from fermented meat products. Resistance to tetracycline was found to be one of the most distributed resistances occurring in strains isolated from fermented sausages. We evaluated the transfer of tetracycline resistance and between strains. We selected three strains isolated from dry fermented sausages, resistant to tetracycline but not to minocycline, their resistance occurring by a mechanism of active efflux encoded by the gene. Only one strain was able to transfer its tetracycline resistance to a recipient strain initially susceptible and plasmid-free using a filter mating procedure. Transfer of tetracycline resistance was observed at very low frequencies of 3.4 × 10 per recipient. To further investigate the transferability of this tetracycline resistance, the donor and recipient strains were tested in pilot-scale fermented sausage production. This transfer was possible but at a low rate, 1.4 × 10, and only under conditions of a high inoculation level of 10 CFU/g of meat. The gene is located on a small mobilizable plasmid close to pT181 plasmid. In conclusion, the transfer of tetracycline resistance between strains of is possible, but at a really low frequency and in fermented sausages. Even if this represents a very moderate risk, it should be taken into account as required by the European approach of Qualified Presumption of Safety (QPS) and AFSSA safety recommendations, advising that strains used as starter cultures should not carry any transferable antibiotic resistance.
抗生素耐药决定因素的存在可能会在凝固酶阴性葡萄球菌（CNS）中构成安全隐患，这类细菌广泛存在于动物源性食品中。在CNS中， 是一种经常从发酵肉制品中分离出来的菌种。对四环素的耐药性被发现是从发酵香肠中分离出的 菌株中分布最广的耐药性之一。我们评估了四环素耐药性在 菌株之间的转移情况。我们从干发酵香肠中挑选了三株对四环素耐药但对米诺环素不耐药的菌株，它们的耐药性是由 基因编码的主动外排机制产生的。只有一株菌株能够通过滤膜接合程序将其四环素耐药性转移给最初敏感且无质粒的受体菌株。四环素耐药性的转移频率非常低，为每受体3.4×10 。为了进一步研究这种四环素耐药性的可转移性，供体和受体菌株在中试规模的发酵香肠生产中进行了测试。这种转移是可能的，但发生率很低，为1.4×10 ，而且只有在肉接种水平为10 CFU/g的高接种条件下才会发生。 基因位于一个靠近 pT181质粒的小型可移动质粒上。总之， 菌株之间四环素耐药性的转移是可能的，但在发酵香肠中的频率非常低。即使这代表的风险非常小，但根据欧洲的安全合格假定（QPS）方法和法国食品安全局（AFSSA）的安全建议，也应予以考虑，这些建议指出用作发酵剂的菌株不应携带任何可转移的抗生素耐药性。
