[Frequency and characterization of "Neisseria lactamica" among the population of Milan Italy (author's transl)].

In 1979, 4,941 asymptomatic subjects, ranging from children to adolescents and working-age adults living in the Milan area, were examined for the presence of neisseriae in rhinopharyngeal exudate. 382 carriers of neisseriae were identified (7.7%); of these, 265 (5.3%) presented Neisseria meningitidis and 117 (2.4%) Neisseria lactamica. Carriers of Neisseria lactamica were found more frequently among children and adolescents than among adults of working age. The strains of Neisseria lactamica isolated showed the same degree of sensitivity and resistance to chemoantibiotics as Neisseria meningitidis strains. Difficulty was found in serotyping the strains of Neisseria lactamica isolated, due to tendency to polyagglutinability. The Author stresses the need to include the lactose test in the identification of neisseria, in order to differentiate between Neisseria lactamica and Neisseria meningitidis.