Browsing by Author "Zuo, Jiakun"

Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Molecular epidemiology and antimicrobial resistance of outbreaks of Klebsiella pneumoniae clinical mastitis in Chinese dairy farms
    (American Society for Microbiology, 2022-11-14) Fu, Shaodong; Wen, Chen; Wang, Zhenglei; Qiu, Yawei; Zhang, Yihao; Zuo, Jiakun; Xu, Yuanyuan; Han, Xiangan; Luo, Zhenhua; Chen, Wei; Miao, Jinfeng
    Klebsiella pneumoniae is an opportunistic pathogen that causes serious infections in humans and animals. However, the availability of epidemiological information on clinical mastitis due to K. pneumoniae is limited. To acquire new information regarding K. pneumoniae mastitis, data were mined about K. pneumoniae strains on dairy cattle farms (farms A to H) in 7 Chinese provinces in 2021. Hypermucoviscous strains of K. pneumoniae were obtained by the string test. MICs of antimicrobial agents were determined via the broth microdilution method. Ten antimicrobial resistance genes and virulence genes were identified by PCR. The prevalence of K. pneumoniae was 35.91% (65/181), and 100% of the bacteria were sensitive to enrofloxacin. Nine antimicrobial resistance genes and virulence genes were identified and compared among farms. The hypermucoviscous phenotype was present in 94.44% of isolates from farm B, which may be a function of the rmpA virulence gene. Based on these data, the multidrug-resistant strains SD-14 and HB-21 were chosen and sequenced. Genotypes were assayed for K. pneumoniae isolates from different countries and different hosts using multilocus sequence typing (MLST). Ninety-four sequence types (STs) were found, and 6 STs present a risk for spreading in specific regions. Interestingly, ST43 was observed in bovine isolates for the first time. Our study partially reveals the current distribution characteristics of bovine K. pneumoniae in China and may provide a theoretical basis for the prevention and treatment of bovine K. pneumoniae mastitis.
  • Thumbnail Image
    ItemOpen Access
    Taurine alleviates Streptococcus uberis-induced inflammation by activating autophagy in mammary epithelial cells
    (Frontiers, 2021-03-12) Wang, Zhenglei; Lan, Riguo; Xu, Yuanyuan; Zuo, Jiakun; Han, Xiangan; Phouthapane, Vanhnaseng; Luo, Zhenhua; Miao, Jinfeng
    Streptococcus uberis infection can cause serious inflammation and damage to mammary epithelial cells and tissues that can be significantly alleviated by taurine. Autophagy plays an important role in regulating immunity and clearing invasive pathogens and may be regulated by taurine. However, the relationships between taurine, autophagy, and S. uberis infection remain unclear. Herein, we demonstrate that taurine augments PTEN activity and inhibits Akt/mTOR signaling, which decreases phosphorylation of ULK1 and ATG13 by mTOR and activates autophagy. Activating autophagy accelerates the degradation of intracellular S. uberis, reduces intracellular bacterial load, inhibits over-activation of the NF-κB pathway, and alleviates the inflammation and damage caused by S. uberis infection. This study increases our understanding of the mechanism through which taurine regulates autophagy and is the first to demonstrate the role of autophagy in S. uberis infected MAC-T cells. Our study also provides a theoretical basis for employing nutritional elements (taurine) to regulate innate immunity and control S. uberis infection. It also provides theoretical support for the development of prophylactic strategies for this important pathogen.