The present invention provides vaccine compositions and methods of producing such compositions. Other embodiments of the invention include methods of treating a pathogen infection, methods of vaccinating a subject against a pathogen infection, and methods for treating an antibiotic-resistance bacterial infection in a subject in need thereof. In further embodiments, the invention includes methods of decreasing the level of a pathogen in a subject having a pathogen infection, methods of increasing the surviving rate of a subject having a pathogen infection, methods of reducing the level of pain associated with a pathogen infection, and methods of reducing the level of distress associated with a pathogen infection in a subject in need thereof. Novel scaffold compositions and opsonin-bound or lectin-bound pathogen compositions, and uses thereof, are also provided herein.

Compositions and methods for inducing an immune response against extra-intestinal pathogenic Escherichia coli (ExPEC) are described. In particular, multivalent vaccines containing O-antigen polysaccharide covalently bound to an exotoxin A of Pseudomonas aeruginosa (EPA) carrier protein that can withstand multiple environmental stresses are described.

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 subject relates to an isolated antibody that specifically binds to O25b antigen of multi drug resistant (MDR) E. coli strains, its medical and diagnostic use, method of producing the antibody, including an isolated nucleotide sequence, plasmids and host cells as used in the production of the antibody; and further an isolated epitope recognized the specific antibody.

A method for increase the presentation of ETEC CS6 antigen on a cell surface, comprising the step of contacting cells expressing said antigen with an aqueous solution comprising 0.6-2.2 percent phenol by weight, such that the presentation of said antigen is increased by at least 100%. A method for the manufacture of a killed whole cell vaccine for immunization against CS6-expressing ETEC. Cells and vaccines obtainable by the above methods.

Provided herein is an E. coli O polysaccharide, O25B. Also provided herein are prokaryotic host cells containing enzymes (e.g., glycosyltransferases) used in O25B production. The host cells provided herein produce O25B bioconjugates, wherein said bioconjugates contain O25B linked to a carrier protein. Further provided herein are compositions, e.g., pharmaceutical compositions, including O25B and/or bioconjugates containing O25B. Such compositions can be used as vaccines against infection with ExPEC, and may further include one or more additional bioconjugates.

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.

The present invention refers to new glycoconjugate antigens expressing built-in multiple epitopes and to polyvalent glycoconjugate vaccines intended for the protection of mammalians, and particularly for the protection of the human population from enteropathogenic bacteria, such as the Gram-positive anaerobic bacterium Clostridium difficile and the Gram-negative bacteria Salmonella typhi, Escherichia Coli, Vibrio Cholerae, Shigella flexneri, Salmonella typhimurium, Salmonella enteritidis, Salmonella paratyphi A, Shigella sonnei, Shigella dysenteriae, Salmonella cholerasuis, Klebsiella, Enterobacter, Pseudomonas aeruginosa and/or from viral gastrointestinal infections due to human noroviruses.

Vaccine vectors capable of eliciting an immune response to enteric bacteria and methods of using the same are provided. The vaccine vectors include a polynucleotide encoding a PAL polypeptide. The PAL polypeptide may be expressed on the surface of the vaccine vector. The vaccine vector may also include a second polypeptide encoding an immunostimulatory polypeptide such as a CD154 polypeptide or an HMGB1 polypeptide.