Failure of Mycoplasma pneumoniae infection to confer protection against Mycoplasma genitalium: observations from a mouse model

Mycoplasma pneumoniae and M. genitalium are genomically distinct but share antigens that induce some serological cross-reactivity, Therefore, the poss ibility that M, pneumoniae infection of the human respiratory tract might p rovide immunity to M. genitalium infection of the genital tract was conside red. Because of the difficulty of assessing this proposition in man, it was evaluated experimentally in a mouse model. Female BALB/c mice were suscept ible to infection of the vagina with M. pneumoniae, whereas those infected previously in the oropharynx with M. pneumoniae were completely immune to i nfection of the vagina with this mycoplasma, However, all mice with such a respiratory tract infection were susceptible to infection of the vagina wit h M. genitalium. The findings suggest that an M. pneumoniae infection of th e human respiratory tract is unlikely to influence infection of the genital tract by M. genitalium.