Abstract
Recent studies have shown that mice exposed to an aerosol of salmonellae or inoculated intranasally with a drop of saline containing a relatively small number of salmonellae, develop an asymptomatic infection of at least 6 week's duration. Throughout this period salmonellae can be recovered from nasal washings and from the gastrointestinal tract, spleen and lungs of most mice. In contrast, inoculation of a much larger number of salmonellae by the gastric route does not result in prolonged carriage of salmonellae. Investigations were undertaken in an attempt to determine the events occurring in the nasal cavity after inoculation with salmonellae.
Findings show that there is colonization of the nasal cavity by salmonellae and that there is a correlation between numbers in the nose and the spleen. The results support the contention that salmonellae from the nasal cavity could be the source of salmonellae in other tissues. There is already evidence that in epidemics in hospital patients, contaminated dust was the vehicle of transmission. It is possible that the upper respiratory tract of man could be involved in these cases and in the carriage and spread of other Gram-negative bacteria, such as enteropathogenic strains of coli, in hospital environments.