GSE137135
Vaccine protection against multidrug-resistant Klebsiella pneumoniae in a non-human primate model of severe lower respiratory tract infection
Klebsiella pneumoniae is a human gut communal organism and notorious opportunistic pathogen.  The relative high burden of asymptomatic colonization by K. pneumoniae is often compounded by multidrug resistance-a potential problem for individuals with significant comorbidities or other risk factors for infection.  A carbapenem-resistant K. pneumoniae strain classified as multilocus sequence type 258 (ST258) is widespread in the United States and can be resistant to many classes of clinically useful antibiotics. Thus, treatment of ST258 infections is often difficult.  Inasmuch as new preventive and/or therapeutic measures are needed for treatment of such infections, we developed an ST258 pneumonia model in cynomolgus macaques and tested the ability of an ST258 capsule polysaccharide type 2 (CPS2) vaccine to moderate disease severity.  Compared with sham-vaccinated animals, those vaccinated with ST258 CPS2 had significantly less disease as assessed by radiograph 24 h after intrabronchial installation of 108 CFUs of ST258.  All macaques vaccinated with CPS2 ultimately developed ST258-specific antibodies that significantly enhanced serum bactericidal activity and killing of ST258 by macaque neutrophils ex vivo.  Consistent with a protective immune response to CPS2, transcripts encoding inflammatory mediators were increased in infected lung tissues obtained from CPS-vaccinated animals compared with control, sham-vaccinated macaques.  Taken together, our data provide support to the idea that vaccination with ST258 CPS can be used to prevent or moderate infections caused by ST258. As with studies performed decades earlier, we propose that this approach can be extended to include multiple capsule types Overall design: time series