ABSTRACT
In view of the increasing licensure and use of pneumococcal conjugate vaccines, the relatively high cost, and growing issues with serotype emergence, there is a need to re-evaluate the role of pneumococcal protein vaccines (PPVs) and pathways to their licensure. This paper summarizes the discussion and viewpoints from an expert meeting regarding the development of PPVs. A wide spectrum of pneumococcal vaccine researchers, developers, and regulators met to review the state of PPVs, identify research and development needs, and provide consensus opinions to support the introduction of new PPVs where possible. They also discussed clinical and regulatory aspects pertinent to these vaccines and generated a series of recommendations for moving the field forward.
Subject(s)
Pneumococcal Infections/prevention & control , Pneumococcal Vaccines/immunology , Animals , Bacterial Proteins/immunology , Disease Models, Animal , Humans , Pneumococcal Infections/epidemiology , Pneumococcal Vaccines/administration & dosage , Vaccines, Subunit/administration & dosage , Vaccines, Subunit/immunology , Virulence Factors/immunologyABSTRACT
This study investigated the suitability of the Calgary Biofilm Device (CBD), originally designed as a test surrogate for indwelling medical devices, for assessing the efficacy of antimicrobials developed for food and food contact surface disinfection applications. The conditions for the development of uniform biofilms from pure and mixed bacterial cultures of wild type Escherichia coli and Listeria innocua were optimized. We were able to recover approximately 2 x 10(6) colony forming units (CFU) from the biofilms formed on the individual pegs of the device in 24 h. Further, the parameters for the consistent release of the cells from the biofilms were optimized; test showed that the number of cells released was uniform and reproducible. The consistency and reproducibility of the biofilms formed on the pegs was evaluated using scanning electron microscopy and by plate count method. The efficacies of disinfectants on cells residing in biofilms versus planktonic cells were compared. For both species, higher concentrations of disinfectants were needed to eliminate attached cells as compared with planktonic cells. This study establishes the value of the CBD for generating consistent biofilms from either pure or mixed cultures. These biofilms can be used to assess efficacies of disinfectants against cells that have colonized the surfaces of foods and food-processing equipment. Such a system could serve as a standard surrogate for evaluating new disinfectants designed to reduce or eliminate biofilms from food-contact surfaces.
