Mezuzot? Not Muses?

When I first heard that a Rabbi was warning against kissing, I though it was an Orthodox Rabbi warning against kissing "muses", like these:-




But, no, it was "mezuzot", really:-

A Conservative rabbi has recently ruled that kissing mezuzot should be avoided, in order to avoid the risk of contracting an infectious disease.

Rabbi Simcha Roth issued the ruling after he was approached by members of his congregation who expressed concern over the possibility that kissing a mezuzah which has been kissed by other people may constitute a health hazard.