屠宰场待宰生猪及其屠宰过程中金黄色葡萄球菌的污染检测与分析  

Detection and analysis of Staphylococcus aureus contamination in live pigs and in the slaughter process

作　　者：郝勇航 刘俊峰 刘璐函 王鑫盛 吴秋玲 贺恒旭 陈丽颖[1,2] 杨霞[1,2] 宋合强 HAO Yonghang;LIU Junfeng;LIU Luhan;WANG Xinsheng;WU Qiuling;HE Hengxu;CHEN Liying;YANG Xia;SONG Heqiang(College of Veterinary Medicine,Henan Agricultural University,Henan Agricultural University,Zhengzhou 450002,China;Key Laboratory of Animal Food Safety of Henan Province,Zhengzhou 450002,China;Agricultural and Rural Bureau of Zhuozhou City,Hebei Province,Baoding 072750,China)

机构地区：[1]河南农业大学动物医学院,河南郑州450002 [2]河南省动物性食品安全重点实验室,河南郑州450002 [3]河北省涿州市农业农村局,河北保定072750

出　　处：《河南农业大学学报》2021年第4期707-714,共8页Journal of Henan Agricultural University

基　　金：“十三五”国家重点研发计划资助项目(2018YFD0500500)。

摘　　要：通过陕西省和河北省部分地区屠宰场的待宰生猪、屠宰环节胴体及环境采集样本,对金黄色葡萄球菌进行分离鉴定与流行分析。取样地点分别在陕西咸阳某屠宰场和河北保定某屠宰场,3次共采集样品745份。分别采用国家标准GB 4789.10—2016的分离鉴定方法及显色培养基筛选、16S rRNA基因序列分析等方法进行了生猪从待宰到屠宰环节中的金黄色葡萄球菌污染检测,并进行了耐甲氧西林金黄色葡萄球菌(MRSA)筛查。检测结果显示,从745份样品中共分离出金黄色葡萄球菌98株,总分离率为13.2%;其中,在屠宰场1a、屠宰场1b和屠宰场2样本中的检出率分别为15.6%、10.4%和13.8%,3次检测结果无明显相关性(P>0.05);从采样部位看,猪鼻腔拭子样本中金葡菌阳性率最高,平均为20.5%,明显高于体表拭子样本检出率平均5.5%(P<0.01),这说明待宰生猪及宰后猪鼻腔为金黄色葡萄球菌的主要污染部位;在屠宰场地面、空气及器具样本中均检出了金黄色葡萄球菌,说明屠宰场环境中存在金葡菌污染,其中以屠宰场2较为严重。进一步筛查与分析结果显示,上述98个金黄色葡萄球菌分离株中有12个为MRSA菌株(12.2%),且其中11株来自屠宰场2。对seb等10个特异性肠毒素基因的检测结果表明,携带肠毒素基因的菌株在3批(屠宰场1a、1b和2)金葡菌分离株中分别占比42.9%、29.6%和44.4%;肠毒素基因的总体检出率为10.6%,其中以sem、sei、sen、seg、sek的检出频次较高;大部分金葡菌分离株携带肠毒素基因数≤3个,但来自屠宰场2的2个MRSA菌株均携带≥5个肠毒素基因,这提示了毒力基因与MRSA菌株高致病性的关联性。研究结果表明,金黄色葡萄球菌等食源性病原菌在生猪养殖到屠宰等各个环节中都存在着不同程度的污染与传播,不同屠宰场食源性致病菌的污染传播存在一定差异。高度耐药的超级致病株MRSA在待宰生猪、屠宰环节甚In this study,samples were collected from slaughterhouse pigs,tools and environments in Shaanxi province and Hebei province for Staphylococcus aureus isolation,identification and prevalence analysis.The slaughterhouses are located in Xianyang,Shaanxi province and in Baoding,Hebei province,respectively,and for three times a total of 745 samples were obtained.Bacterial inspection methods based on GB 4789.10—2016 national standard,chromogenic media screening and 16S rRNA gene sequencing were applied to detect Staphylococcus aureus contamination in live and slaughtered pigs,and methicillin-resistant Staphylococcus aureus(MRSA)strains were identified.The test results showed that 98 S.aureus strains were isolated from 745 samples,with a general isolation rate of 13.2%;among the samples from Slaughterhouse 1a,1b and 2,the detection rate was 15.6%,10.4%and 13.8%,respectively,and no significant correlation was present(P>0.05).The highest prevalence was detected in nasal swab samples,whose average positive rate was 20.6%,apparently higher than that in body surface swab samples(5.6%)(P<0.01),indicating that nasal cavity is the most predominant site for S.aureus dwelling.Some S.aureus isolates were also obtained in environmental samples such as air,water,floor and tools,implying that there is S.aureus contamination in slaughterhouse environments,with Slaughterhouse 2 the most predominant.Further studies showed that 12 of the 98 Staphylococcus aureus isolates were MRSA strains(12.24%),and 11 of them were fromSlaughterhouse 2.The PCR results of 10 specific enterotoxin genes showed that enterotoxin positive S.aureus strains covered 42.9%,29.6%,and 44.4%of the batches from Slaughterhouse 1a,1b and 2,respectively;the general positive rate of enterotoxin genes was 10.6%,of which sem,sei,sen,seg,and sek were most frequently detected.Most of the S.aureus isolates carried≤3 enterotoxin genes,but≥5 enterotoxin genes were present in the two MRSA strains from Slaughterhouse 2,correlating virulence genes with high pathogenicity of

关 键 词：生猪 屠宰场 金黄色葡萄球菌 MRSA 肠毒素 

分 类 号：S858[农业科学—临床兽医学]