The enterococci are ubiquitous bacteria able to colonize the human and animal gastrointestinal tracts and fresh and fermented food products. Their highly plastic genome allows Enterococcus spp. to gain resistance to multiple antibiotics, making infections with these organisms difficult to treat. Food-borne enterococci could be carriers of antibiotic resistance determinants. The goal of this work was to study the characteristics of Enterococcus spp. in fermented milk products from Poland and their antibiotic resistance gene profiles. A total of 189 strains were isolated from 182 dairy products out of 320 samples tested. The predominant species were Enterococcus faecium (53.4%) and Enterococcus faecalis (34.4%). Isolates were resistant to streptomycin (29.1%), erythromycin (14.3%), tetracycline (11.6%), rifampicin (8.7%), and tigecycline (8.1%). We also detected 2 vancomycin-resistant and 3 linezolid-resistant strains; however, no vanA or vanB genes were identified. A total of 57 high-level aminoglycoside resistance strains (30.2%) were identified, most of which have the ant(6')-Ia gene, followed by the aac(6')-Ie-aph(2″)-Ia and aph(3″)-IIIa genes. Resistance to tetracycline was most often conferred by tetM and tetL genes. Macrolide resistance was most frequently encoded by ermB and ermA genes. Conjugative mobile genetic element (transposon Tn916-Tn1545) was identified in 15.3% of the strains, including 96.3% of strains harboring the tetM gene. This study found that enterococci are widely present in retail ready-to-eat dairy products in Poland. Many isolated strains are antibiotic resistant and carry transferable resistance genes, which represent a potential source of transmission of multidrug-resistant bacteria to humans.

中文翻译：

---

即食乳制品作为耐多药肠球菌菌株的来源：表型和基因型特征。

肠球菌是无处不在的细菌，能够在人和动物的胃肠道以及新鲜和发酵的食品中定殖。其高度可塑性的基因组允许肠球菌属。对多种抗生素产生抗药性，使这些生物的感染难以治疗。食源性肠球菌可能是抗生素耐药性决定因素的载体。这项工作的目的是研究肠球菌的特征。波兰发酵乳制品中的维生素及其抗生素抗性基因谱。从320个测试样品中共从182个乳制品中分离出189个菌株。主要种类为粪肠球菌（53.4％）和粪肠球菌（34.4％）。分离株对链霉素（29.1％），红霉素（14.3％），四环素（11.6％），利福平（8.7％）和替加环素（8.1％）有抗性。我们还检测了2株耐万古霉素和3株耐利奈唑胺的菌株。然而，没有鉴定出vanA或vanB基因。总共鉴定出57个高水平氨基糖苷抗药性菌株（30.2％），其中大多数具有ant（6'）-Ia基因，其次是aac（6'）-Ie-aph（2″）-Ia和aph（3″）-IIIa基因。对四环素的抗性通常是由tetM和tetL基因赋予的。大环内酯类抗药性最常见的是由ermB和ermA基因编码。在15.3％的菌株中鉴定出结合移动遗传元件（转座子Tn916-Tn1545），其中96.3％的菌株带有tetM基因。这项研究发现，肠球菌广泛存在于波兰的零售即食乳制品中。许多分离出的菌株具有抗生素抗性并带有可转移的抗性基因，