Prevalence, antimicrobial susceptibility, and molecular characterization of Staphylococcus aureus isolated from dairy herds in northern China

被引：95

作者：

Liu, Huimin ^{[1
,2
]}

Li, Songli ^{[1
,2
]}

Meng, Lu ^{[1
,2
]}

Dong, Lei ^{[1
,2
]}

Zhao, Shengguo ^{[1
,2
]}

Lan, Xinyi ^{[1
,2
]}

Wang, Jiaqi ^{[1
,2
]}

Zheng, Nan ^{[1
,2
]}

机构：

[1] Chinese Acad Agr Sci, Minist Agr, Inst Anim Sci, Lab Qual & Safety Risk Assessment Dairy Prod Beij, Beijing 100193, Peoples R China

[2] Minist Agr, Milk & Dairy Prod Inspect Ctr Beijing, Beijing 100193, Peoples R China

来源：

JOURNAL OF DAIRY SCIENCE | 2017年 / 100卷 / 11期

关键词：

antimicrobial resistance; enterotoxins; northern China; raw milk; Staphylococcus aureus; BOVINE MASTITIS; GOAT MILK; RAW-MILK; RESISTANCE; GENES; FOOD; CHEESE;

D O I：

10.3168/jds.2017-13370

中图分类号：

S8 [畜牧、动物医学、狩猎、蚕、蜂];

学科分类号：

0905 ;

摘要：

Staphylococcus aureus is one of the main pathogens involved in dairy cow mastitis. Monitoring of antibiotic use would prove useful to assess the risk of Staph. aureus in raw milk. The objective of this work was to investigate the prevalence of Staph. aureus strains isolated from raw milk in northern China, and to characterize antimicrobial susceptibility of these strains and their key virulence genes. In total, 195 raw milk samples were collected from 195 dairy farms located in 4 cities of northern China from May to September 2015. Out of 195 samples, 54 (27.7%) were positive for Staph. aureus. Among these 54 samples, 54 strains of Staph. aureus were isolated, and 16 strains were identified as methicillin-resistant Staph. aureus. The strains exhibited high percentages of resistance to penicillin G (85.2%), ampicillin (79.6%), and erythromycin (46.3%). Moreover, 72% of the strains showed resistance to more than one antimicrobial agent. Overall, 63% of penicillin-resistant strains possessed the blaZ gene, and 60% of the erythromycin-resistant strains possessed erm(A), erm(B), erm(C), msr(A), or msr(B) genes with 8 different gene patterns. All isolates resistant to gentamicin, kanamycin, and oxacillin carried the aac6'-aph2", ant(4')-Ia, and mecA genes, respectively. Two tet(M)-positive isolates carried specific genes of the Tn9/6-Tn/545 transposon. The most predominant virulence genes were sec, sea, and pvl, which encode staphylococcal enterotoxins (sec and sea) and PantonValentine leukocidin, respectively. Thirty-two isolates (59.2%) harbored one or more virulence genes. The majority of Staph. aureus strains were multidrug resistant and carried multiple virulence genes, which may pose a risk to public health. Our data indicated that antimicrobial resistance of Staph. aureus was prevalent in dairy herds in northern China, and that antibiotics, especially penicillin G and ampicillin, to treat mastitis caused by Staph. aureus should be used with caution in northern China.

引用

页码：8796 / 8803

页数：8

共 30 条

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