Acta Veterinaria et Zootechnica Sinica ›› 2022, Vol. 53 ›› Issue (2): 529-537.doi: 10.11843/j.issn.0366-6964.2022.02.019

• PREVENTIVE VETERINARY MEDICINE • Previous Articles     Next Articles

Construction and Biological Characteristic of Glaesserella parasuis Strain with qseB, qseC Double Gene Deletion

HE Lüqin1,2, YAN Xuefeng3, WEN Xintian1, CAO Sanjie1, HUANG Xiaobo1, WU Rui1, ZHAO Qin1, WEN Yiping1*   

  1. 1. Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China;
    2. Experimental Animal Center, Technology Department, Southwest Medical University, Luzhou 646000, China;
    3. School of Physical Education, Southwest Medical University, Luzhou 646000, China
  • Received:2021-06-11 Online:2022-02-23 Published:2022-03-02

Abstract: The QseBC two-component system (TCS) is related to quorum sensing of bacteria. As a global regulator of virulence in Enterobacteriaceae and Pasteurellaceae, its role still unclear in Glaesserella (Haemophilus) parasuis. In this study, the double gene deletion mutant ΔqseBC of SC1401 was constructed by natural transformation method. The serum resistance ability, biofilm formation, antibiotic resistance and stress tolerance of ΔqseBC mutant strain and wild strain SC1401 were measured. Results were as follows:the biofilm-forming ability of ΔqseBC was significantly weaker than that of the wild strain SC1401. The survival rate of the ΔqseBC mutant in porcine serum was 55.12%, which was lower than that of the wild strain SC1401 (83.76%). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ΔqseBC mutant strain to enrofloxacin, gentamicin, ceftiofur and penicillin were significantly decreased. The ΔqseBC mutant strain showed high sensitivity to high temperature (39 and 42℃), hydrogen peroxide (1, 2, 4, 8 and 16 mmol·L-1) and NaCl (50, 100 and 150 mmol·L-1). The results showed that the TCS QseBC plays an important role in the serum resistance, antibiotic resistance and stress tolerance of Glaesserella parasuis. The above findings revealed that QseBC might be closely related to the pathogenicity of Glaesserella parasuis, but further studies are needed to determine the specific mechanism.

Key words: QseBC, serum resistance, biofilm, antibiotic resistance, stress tolerance

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