食品科学 ›› 2020, Vol. 41 ›› Issue (17): 169-175.doi: 10.7506/spkx1002-6630-20190730-407

• 营养卫生 • 上一篇    下一篇

牦牛屠宰中金黄色葡萄球菌分离菌株的流行特征

屈云,佟尧,谈永萍,赵燕英,唐俊妮   

  1. (西南民族大学生命科学与技术学院,四川 成都 610041)
  • 出版日期:2020-09-15 发布日期:2020-09-16
  • 基金资助:
    “十三五”国家重点研发计划重点专项(2018YFD0500500);四川省科技计划项目(2019YJ0261); 西南民族大学研究生创新课题(CX2019SZ121)

Epidemiological Characteristics of Staphylococcus aureus Isolates Collected during Yak Slaughter

QU Yun, TONG Yao, TAN Yongping, ZHAO Yanying, TANG Junni   

  1. (College of Life Science and Technology, Southwest Minzu University, Chengdu 610041, China)
  • Online:2020-09-15 Published:2020-09-16

摘要: 为研究牦牛屠宰过程中金黄色葡萄球菌分离菌株的流行特征,本实验选取成都市某牦牛屠宰场采集样品共计150 份,采用Baird-Parker选择性培养基初步筛选出金黄色葡萄球菌疑似菌株,通过聚合酶链式反应检测携带金黄色葡萄球菌特有耐热核酸酶基因的菌株。进一步检测分离菌株21 种肠毒素基因、6 种毒力基因、4 种耐消毒剂基因以及14 种耐药基因的携带情况。并采用K-B纸片扩散法检测菌株对24 种抗生素的耐药表型。结果表明,从150 份牦牛屠宰场采集到的样品中,检出金黄色葡萄球菌67 株,检出率为44.67%,其中牦牛胴体拭子和环境拭子采样中金黄色葡萄球菌的检出率较高,分别为56.67%和51.61%;分离菌株中共检出12 种肠毒素基因,其中selx、seu和sej基因的检出率高;分离菌株检测出溶血毒素基因、杀白细胞素基因以及qacA/B、qacG、qacH等耐消毒剂基因;有11 种耐药基因检测出阳性条带,其中,耐甲氧西林基因mecA检出率为62.69%,氨基糖苷类耐药基因(aac6’/aph2’)和大环内脂类耐药基因(ermA、ermB)的检出率较高。K-B纸片扩散法对67 株分离菌株进行24 种抗生素的药敏实验结果表明大部分受试菌株存在多重耐药性。本实验通过对牦牛屠宰过程金黄色葡萄球菌流行特征进行调查,发现牦牛屠宰环节存在携带毒力基因且多重耐药金黄色葡萄球菌的污染,有可能进入食物链对消费者健康存在潜在威胁,研究结果为评价牦牛屠宰环节金黄色葡萄球菌安全风险提供参考依据。

关键词: 牦牛屠宰;金黄色葡萄球菌;分离鉴定;毒力基因;耐药表型

Abstract: To study the epidemiological characteristics of Staphylococcus aureus isolates from yak slaughterhouses, 150 biological samples were collected from a yak slaughterhouse in Chengdu. Strains suspected of being S. aureus were isolated using Baird-Parker medium and the ones carrying the heat-resistant nuclease gene (nuc) unique to S. aureus were identified by polymerase chain reaction (PCR). The S. aureus strains were examined for whether they carried 21 enterotoxin genes, 6 virulence genes, 4 disinfectant resistance genes, or 14 drug resistance genes. The susceptibility of the S. aureus isolates to 24 antibiotics was detected by disk diffusion method. The results showed that 67 S. aureus strains were isolated and identified from the 150 samples with a detection rate of 44.67%. The detection rate was relatively high in carcass and environmental swab samples, 56.67% and 51.61%, respectively. A total of 12 enterotoxin genes were detected in the isolates, among which the carrying rates of selx, seu and sej genes were high. We also confirmed the presence of the virulence genes (hlα, hlβ, eta, etb, pvl, and tsst-1), the disinfectant resistance genes (qacA/B, qacG, and qacH), and 11 drug-resistant genes. Eleven positive bands were found for antibiotic resistance genes. Notably, the detection rate of the methicillin-resistant gene (mecA) was 62.69%, and the detection rates of the aminoglycoside-resistant gene (aac6’/aph2’) and the macrolide-resistant gene (erm) were high. Most of the 67 isolates had multi-drug resistance. The epidemiological characteristics of S. aureus during the slaughter process of yaks demonstrated contamination with multi-drug resistant S. aureus with carrying virulence genes, which may pose potential threats to consumers’ health through the food chain. This study provides reference for evaluating the risk of S. aureus contamination during yak slaughter.

Key words: yak slaughter; Staphylococcus aureus; isolation and identification; virulence gene; drug-resistant phenotype

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