从奶牛临床和亚临床乳腺炎中分离出的耐多药金黄色葡萄球菌的毒力特征、葡萄球菌A蛋白分型、多重耐药模式及生物膜形成能力

Virulence traits, agr typing, multidrug resistance patterns, and biofilm ability of MDR Staphylococcus aureus recovered from clinical and subclinical mastitis in dairy cows.

作者信息

Eidaroos Nada H, Algammal Abdelazeem M, Mohamaden Walaa Ismail, Alenzi Asma Massad, Alghamdi Saad, Kabrah Ahmed, El-Mahallawy Heba Sayed, Eid Hamza M, Algwad Alaa Abd, Asfor Samar Ali, Neubauer Heinrich, Moawad Amira A, El-Tarabili Reham M

机构信息

Department of Bacteriology, Immunology, and Mycology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt.

Department of Animal Medicine, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt.

出版信息

BMC Microbiol. 2025 Mar 19;25(1):155. doi: 10.1186/s12866-025-03870-3.

DOI:10.1186/s12866-025-03870-3

PMID:40102767

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11921537/

Abstract

BACKGROUND

Bovine mastitis caused by Staphylococcus aureus is considered a public health threat globally. Herein, we aimed to investigate the occurrence, agr typing, antimicrobial resistance patterns, biofilm production, and PCR-based detection of the virulence, biofilm, adhesion, and enterotoxins genes of S. aureus strains recovered from clinical and subclinical bovine mastitis.

RESULTS

The prevalence of S. aureus in the examined milk samples was 44.4%. Besides, 95% of the retrieved S. aureus strains were identified as MRSA. Herein, all the tested isolates were biofilm producers. PCR revealed that 85% of the retrieved S. aureus strains were positive for the agr I gene. Furthermore, the clfB, clfA, fnbB, fnbA, and cna genes were detected with a prevalence of 100%, 80%, 60%, 55%, and 30%, respectively. Also, all the tested S. aureus strains were positive for the coa gene (100%). Besides, 92.5% and 85% of the recovered strains harbored the lukF and spa genes, respectively. In addition, the prevalence of the hla, hlb, and hlg hemolysin genes was 70%, 50%, and 35%, respectively. Among the enterotoxin genes, the seb gene was detected in 30% of the tested strains. The prevalence of eno and icaA biofilm genes was 95% in the tested strains. Moreover, 15% of S. aureus strains were MDR to 8 antimicrobial agents and harbored the mecA, ermC, and ermB genes. As well, 12.5% of S. aureus strains were MDR to 8 antimicrobial agents and carried the mecA, ermC, ermB, tetK, and tetM genes. Also, 5% of S. aureus strains were XDR to 11 antimicrobial agents and carried the mecA, ermC, and ermB genes.

CONCLUSIONS

The existence of MDR and XDR MRSA strains in bovine milk is a public health hazard. The mecA, ermC, ermB, tetK, and tetM resistance genes and the coa, clfB, eno, icaA, lukF, spa, clfA, and hla virulence genes are commonly associated with the MDR and XDR MRSA strains. Moreover, the seb gene was the predominant enterotoxin gene in the MRSA strains recovered from milk.

摘要

背景

由金黄色葡萄球菌引起的牛乳腺炎被认为是全球范围内的公共卫生威胁。在此，我们旨在调查从临床和亚临床牛乳腺炎中分离出的金黄色葡萄球菌菌株的发生率、agr分型、抗菌药物耐药模式、生物膜形成以及基于PCR的毒力、生物膜、黏附及肠毒素基因检测。

结果

在所检测的牛奶样本中，金黄色葡萄球菌的患病率为44.4%。此外，95%的分离出的金黄色葡萄球菌菌株被鉴定为耐甲氧西林金黄色葡萄球菌（MRSA）。在此，所有测试菌株均能产生生物膜。PCR检测显示，85%的分离出的金黄色葡萄球菌菌株agr I基因呈阳性。此外，clfB、clfA、fnbB、fnbA和cna基因的检出率分别为100%、80%、60%、55%和30%。同样，所有测试的金黄色葡萄球菌菌株coa基因均呈阳性（100%）。此外，92.5%和85%的分离菌株分别携带lukF和spa基因。另外，hla、hlb和hlg溶血素基因的患病率分别为70%、50%和35%。在肠毒素基因中，30%的测试菌株检测到seb基因。测试菌株中eno和icaA生物膜基因的患病率为95%。此外，15%的金黄色葡萄球菌菌株对8种抗菌药物多重耐药，并携带mecA、ermC和ermB基因。同样，12.5%的金黄色葡萄球菌菌株对8种抗菌药物多重耐药，并携带mecA、ermC、ermB、tetK和tetM基因。还有，5%的金黄色葡萄球菌菌株对11种抗菌药物广泛耐药，并携带mecA、ermC和ermB基因。

结论

牛奶中存在多重耐药和广泛耐药的MRSA菌株是一种公共卫生危害。mecA、ermC、ermB、tetK和tetM耐药基因以及coa、clfB、eno、icaA、lukF、spa、clfA和hla毒力基因通常与多重耐药和广泛耐药的MRSA菌株相关。此外，seb基因是从牛奶中分离出的MRSA菌株中主要的肠毒素基因。