Neisseria models of infection and persistence in the upper respiratory tract

The Gram-negative bacteria genus Neisseria includes both pathogenic and commensal species that are found primarily in the upper respiratory tract of humans and animals. The development of animal models to study neisserial pathogenesis has focused almost exclusively on two species that cause disease in humans. These include Neisseria meningitidis, an obligate commensal that can cause invasive disease, and N. gonorrhoeae, the causative agent of gonorrhea. Both pathogens can persist in the upper respiratory tract. This article will give a brief overview of the genus Neisseria. The anatomy of the upper respiratory tract and its use as a niche for bacteria will be discussed. Next, studies that provide insight about the first stage of upper respiratory tract infection, namely colonization, will be reviewed. Most studies of upper respiratory tract infection have focused on N. meningitidis infections of laboratory mice. This review will also discuss models of respiratory tract persistence by Neisseria species, including commensals, in mice, non-human primates and human volunteers. The article includes a section that discusses the future utility of upper respiratory tract models in informing the development of effective antimicrobial therapies. Such knowledge is needed to minimize the dissemination of antimicrobial resistance from respiratory reservoirs.