Synergy of bacteriophage depolymerase with host immunity rescues sepsis mice infected with hypervirulent Klebsiella pneumoniae of capsule type K2

Autor: Deyi Zhao, Miran Tang, Zhexiao Ma, Panjie Hu, Qingxia Fu, Zhuocheng Yao, Cui Zhou, Tieli Zhou, Jianming Cao
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Virulence, Vol 15, Iss 1 (2024)
Druh dokumentu: article
ISSN: 21505594
2150-5608
2150-5594
DOI: 10.1080/21505594.2024.2415945
Popis: The hypervirulent Klebsiella pneumoniae (hvKp) with K1 and K2 capsular types causes liver abscess, pneumonia, sepsis, and invasive infections with high lethality. The presence of capsular polysaccharide (CPS) resists phagocytic engulfment and contributes to excessive inflammatory responses. Bacteriophage depolymerases can specifically target bacterial CPS, neutralizing its defense. Based on our previous research, we expressed and purified a bacteriophage depolymerase (Dep1979) targeting hvKp with capsule type K2. Interestingly, although Dep1979 lacked direct bactericidal activity in vitro, it exhibited potent antibacterial activity in vivo. Low-dose Dep1979 (0.1 mg/kg) improved the 7-day survival of immunocompetent mice to 100%. Even at 0.01 mg/kg, mice achieved 100% survival at 5 days, although efficacy sharply declined at doses as low as 0.001 mg/kg. Following Dep1979 treatment, reduced expression of inflammatory factors and no apparent tissue damage were observed. However, therapeutic efficacy significantly diminished in immunosuppressed mice. These findings underscore the critical role of Dep1979 in disarming CPS, which synergizes with host immunity to enhance antibacterial activity against hvKp.
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