Provided herein are isolated proteins isolatable from a Klebsiella spp. Also provided are compositions that include one or more of the proteins, and methods for making and methods for using the proteins.

Provided herein are glycosylated ComP proteins, fragments and fusion proteins thereof, and methods of making, for example, for use in the production of conjugate vaccines. Also provided herein are conjugate vaccines against diseases including bacterial diseases.

The invention provides peptides derived from a ubiquitous protein, and nucleic acids encoding such peptides. The invention extends to various uses of these peptides and nucleic acids, for example, as antigens for use in vaccines per se and in the generation of antibodies for use in therapeutic drugs for the prevention, amelioration or treatment of infections caused by sepsis-inducing bacteria. The invention particularly benefits immunocompromised hosts such as neonates, babies, children, women of fertile age, pregnant women, foetuses, the elderly and diabetics.

The disclosure provides various immunogens comprising a repeat unit of saccharide of Klebsiella pneumoniae CPS, which has a formula selected from the group consisting of Formulae (I) to (VI) as described herein. Also provided are vaccines including one or more immunogens selected from Formula (I) to (VI) and methods of eliciting an immune response against a Klebsiella pneumoniae and preventing infection of Klebsiella pneumoniae by using an immunogen of the invention.

Polypeptides comprising a FimH lectin domain comprising an amino acid mutation that causes the FimH lectin domain to be in the low affinity conformation for mannose are described. Pharmaceutical compositions which comprise such polypeptides and methods of stimulating an immune response in a subject in need thereof by administration of the polypeptide are further described.

The present invention relates to a synthetic saccharide of general formula (I) that is related to Klebsiella pneumoniae serotype O1, O2, O2ac, and O8 O-polysaccharide and carbapenem-resistant Klebsiella pneumoniae ST258 O-polysaccharide and conjugate thereof. Said synthetic saccharide, said conjugate and pharmaceutical composition containing said synthetic saccharide or said conjugate are useful for prevention and/or treatment of diseases associated with Klebsiella pneumoniae. Furthermore, the synthetic saccharide of general formula (I) is useful as marker in immunological assays for detection of antibodies against Klebsiella pneumoniae bacteria.

A SD-1 strain of Klebsiella pneumoniae from mink and its application are disclosed, wherein the collection number of the Klebsiella pneumoniae is CGMCC NO: 17901. The Klebsiella pneumoniae SD-1 strain can be used for preparing a vaccine. The preferred form of the vaccine is an inactivated vaccine. The SD-1 strain of Klebsiella pneumoniae was screened from minks that died after vaccination. Compared with the current Klebsiella pneumoniae, the strain has mutated and is a new type of pathogenic strain. Vaccine prepared from the SD-1 strain provides better immune protection for minks.

This invention provides a polypeptide derived from E. coli or a fragment thereof, including compositions and methods thereof. In one embodiment, the compositions comprise a polypeptide derived from E. coli or a fragment thereof; and modified O-polysaccharide molecules derived from E. coli lipopolysaccharides or conjugates thereof. In a further aspect, the compositions further comprise modified O-polysaccharide molecules derived from Klebsiella pneumoniae or conjugates thereof.

The invention provides methods of modulating an immune system in a vertebrate host for the therapeutic or prophylactic treatment of infection by a first microbial pathogen in a target tissue, comprising administration at an administration site of an effective amount of an antigenic formulation comprising antigenic determinants specific for a second heterologous microbial pathogen.

Provided herein are isolated proteins isolatable from a Klebsiella spp. Also provided are compositions that include one or more of the proteins, and methods for making and methods for using the proteins.