Lactamica

Lactamica is a genus of bacteria in the family Neisseriaceae. The best known species is Lactamica lactamica, a commensal inhabitant of the human upper respiratory tract, particularly in children, where it is carried asymptomatically.

Morphology and physiology: Members of Lactamica are Gram-negative diplococci that resemble other Neisseriaceae in cellular shape. They are typically oxidase positive and are usually cultured from mucosal surfaces of the nasopharynx. Growth is often observed on enriched media such as chocolate agar, and they are commonly recovered in pediatric populations.

Ecology and pathogenicity: Lactamica species are generally considered non-pathogenic commensals in healthy individuals. In rare cases, infections may occur in immunocompromised hosts, but such events are uncommon relative to related pathogenic species.

Clinical and research relevance: The presence of Lactamica lactamica in early life has been associated with the development of antibodies that cross-react with Neisseria meningitidis, suggesting a possible contribution to natural immunity against meningococcal disease. Because of this relationship, L. lactamica has been used as a model organism in studies of meningococcal colonization and mucosal immunity, and research has explored its potential role in vaccine strategies.

Taxonomy: The genus contains multiple species within the Neisseriaceae family; taxonomic distinctions from Neisseria have often been discussed in the context of shared ancestry and certain phenotypic traits.