S. epidermidis strains from artisanal cheese made from unpasteurized milk in Poland - Genetic characterization of antimicrobial resistance and virulence determinants
S. epidermidis strains from artisanal cheese made from unpasteurized milk in Poland - Genetic characterization of antimicrobial resistance and virulence determinants
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DOI：
10.1016/j.ijfoodmicro.2019.02.004
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发表时间：
2019-04-02
影响因子：
5.4
通讯作者：
Gajewska, Joanna
中科院分区：
文献类型：
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作者：
Chajgcka-Wierzchowska, Wioleta;Zadernowska, Anna;Gajewska, Joanna
在波兰，手工奶酪生产是当地重要的经济活动。手工奶酪通常使用生牛奶、动物凝乳酶和盐生产，不添加发酵剂。凝固酶阴性葡萄球菌 (CoNS) 经常存在于手工奶酪中。一些 CoNS 物种（尤其是表皮葡萄球菌）的致病潜力表明它们可能对应于新出现的病原体。已确定的风险因素对应于毒力、抗生素耐药性和生物膜形成。因此，我们的目的是表征沿着手工原料奶生产链分离的表皮葡萄球菌。这项研究包括从波兰波德拉谢、瓦尔米亚和马祖里地区购买的未经高温消毒的牛奶中提取的 70 种手工奶酪样品。总共获得了 26 个表皮葡萄球菌分离株。其中大多数对抗菌药物具有耐药性，例如青霉素（84.6%）、克林霉素（46.2%）、四环素（42.3%）、红霉素（42.3%）和头孢西丁（26.9%）。只有一种分离株对研究中使用的所有抗生素敏感。所有耐甲氧西林表皮葡萄球菌菌株（26.9%）均携带 mecA 基因。对四环素具有表型抗性的分离株至少具有一种四环素抗性决定簇，其中 tet(M) 最常见。此外，所有四环素抗性菌株都含有Tn916-Tn 545样整合酶家族基因。在红霉素抗性分离株中，存在大环内酯类抗性基因ermC、errnB或msrA/B。 7株菌株表现出较强的生物膜形成能力，4株菌株表现出中等和弱的生物膜能力，而11株表皮葡萄球菌分离株被发现无法形成生物膜。所有产生强生物膜的菌株都含有icaD基因，该基因独立出现或与icaA组合出现。在 15.4% 的表皮葡萄球菌菌株中鉴定出插入元件 IS256，所有这些菌株都具有多重耐药性。在 26 个检查菌株中的 13 个（50%）中鉴定出了精氨酸分解代谢移动元件 (ACME)。最常见的是 ACME I 型 (26.9%)，其次是 III 型 (15.4%) 和 II 型 (7.7%)。我们的数据表明，表皮葡萄球菌广泛存在于波兰用生全脂牛奶制成的手工奶酪中。许多分离的菌株含有更多毒力因子和抗生素耐药性，并携带可移动遗传元件，这代表了人类细菌耐药性传播的潜在来源。
In Poland artisanal cheese production is an important local economic activity. Artisanal cheese is usually produced using raw cow's milk, animal rennet and salt, without the addition of starter cultures. Coagulase negative staphylococci (CoNS) are often present in artisanal cheeses. Pathogenic potential of some CoNS species, especially S. epidermidis, suggests that they could correspond to emerging pathogens. The identified risk factors correspond to virulence, antibiotic resistance and biofilm formation. Therefore, we aimed to characterize S. epidermidis isolated along the artisanal raw milk production chain. Seventy artisanal cheeses samples from unpasteurized cow milk purchased in Podlasie and Warmia and Mazury region in Poland, were included in this study. A total of 26 S. epidermidis isolates were obtained. Most of them were antimicrobial resistant, such as to penicillin (84,6%), clindamycin (46,2%), tetracycline (42,3%), erythromycin (42,3%) and cefoxitin (26,9%). Only one isolate was susceptible to all antibiotics used in the study. All methicillin resistant S. epidermidis strains (26,9%) harbored mecA gene. Isolates, phenotypic resistant to tetracycline, harbored at least one tetracycline resistance determinant on which tet(M) was most frequent. Moreover, all tetracycline resistant strains harbored Tn916-Tn 545-like integrase family gene. In the erythromycin resistant isolates, the macrolide resistance genes ermC, errnB or msrA/B were present. Seven strains demonstrated a strong ability to form biofilm and moderate and weak biofilm was demonstrated by 4 strains, whereas 11 of S. epidermidis isolates were found to be unable to form a biofilm. All strains producing strong biofilm harbored the icaD gene which occurred independently or in combination with the icaA. Insertion element IS256, was identified in 15,4% of S. epidermidis strains, all of which were multidrug resistant. Arginine Catabolic Mobile Element (ACME) was identified in 13 of the 26 examined strains (50%). Most common was ACME type I (26,9%), followed by type III (15,4%) and type II (7,7%). Our data indicate that S. epidermidis are widely present in artisanal cheeses from raw whole cow milk in Poland. Many isolated strains containing more virulence factors and antibiotic resistant and carry mobile genetic elements which represent a potential source of resistance transmission to bacteria in humans.