Acta Veterinaria et Zootechnica Sinica ›› 2025, Vol. 56 ›› Issue (11): 5670-5682.doi: 10.11843/j.issn.0366-6964.2025.11.026

• Preventive Veterinary Medicine • Previous Articles     Next Articles

Analysis of Virulence and Antibiotic Resistance Genes in 78 Strains of Staphylococcus aureus from Chicken Arthritis Sources

NIE Lianhua1,2(), FAN Wenyan1,2, LI Mengya1,2, DING Chunhai3, WU Zihao2, WANG Zhihao2, LI Fangfang1,2, JIANG Wei2, HAN Xiangan2,*(), WANG Haidong1,*()   

  1. 1. Shanxi Agricultural University, Taigu 030801, China
    2. Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
    3. Shenyang Aiyou Biotechnology Co., Ltd., Shenyang 110136, China
  • Received:2025-02-20 Online:2025-11-23 Published:2025-11-27
  • Contact: HAN Xiangan, WANG Haidong E-mail:15110991273@163.com;hanxgan@shvri.ac.cn;wanghaidong@sxau.edu.cn

Abstract:

Staphylococcus aureus is a common pathogen in the poultry industry, causing significant economic losses due to its multiple virulence factors and multidrug resistance. To investigate the epidemiological characteristics of Staphylococcus aureus from chicken arthritis sources in Shenyang, Liaoning, a total of 78 strains of Staphylococcus aureus isolated from chicken arthritis sources between 2023 and 2024 were analyzed for virulence and resistance genes. The distribution of virulence genes and antibiotic resistance genes was detected using polymerase chain reaction (PCR). Antibiotic susceptibility was determined by the Kirby-Bauer (K-B) method, and biofilm formation capacity was assessed via crystal violet staining. Among the 15 virulence genes tested, the adhesion gene clfA had the highest detection rate (100%), followed by the adhesion gene clfB (98.7%) and the hemolysin gene hlA (82%). In contrast, the toxic shock syndrome toxin gene tssT (12.8%), enterotoxin gene seA (3.8%), and exfoliative toxin gene etA (1.3%) showed low detection rates. Antibiotic resistance testing against 10 antibiotics revealed that all 78 strains exhibited varying degrees of resistance. High resistance rates were observed for tetracycline (100%), penicillin G (98.7%), norfloxacin (96.2%), clindamycin (89.7%), trimethoprim-sulfamethoxazole (84.6%), gentamicin (82.1%), and erythromycin (79.5%). However, the strains were highly susceptible to cefoxitin and rifampicin (97.4%). Among the 15 antibiotic resistance genes tested, the aminoglycoside resistance genes aac(6') /aph(2″) and ant(4') were detected at rates of 92.3% and 80.8%, respectively. The macrolide resistance genes ermC and ermB were detected at 53.8% and 50.0%, respectively, while the tetracycline resistance gene tetM was only detected in 19.2% of strains. Biofilm formation assays demonstrated that 73 strains (93.6%) exhibited biofilm-forming capacity. Correlation analysis revealed significant associations between aminoglycoside resistance genes (aac(6') /aph(2″) and ant(4')), macrolide resistance genes (ermB and ermC), and the multidrug resistance gene cfr with resistance to gentamicin, erythromycin, and penicillin G, respectively (P < 0.05). For the correlation between biofilm phenotype and antibiotic resistance phenotypes, the results indicated that the development of erythromycin- and chloramphenicol-resistant strains was significantly correlated with biofilm formation (P < 0.05). The 78 strains of Staphylococcus aureus isolated from chicken arthritis exhibited strong drug resistance and a high propensity for biofilm formation, providing valuable insights for the prevention and control of chicken arthritis caused by Staphylococcus aureus in this region.

Key words: Staphylococcus aureus, virulence genes, biofilm, drug resistance

CLC Number: