Effect of antimicrobial factors in human milk on rhinoviruses and milk-borne cytomegalovirus in vitro

Various antimicrobial factors present in human milk were tested for in-vitr o antiviral activity against three rhinoviruses (two clinical isolates and rhinovirus 2) and an isolate of cytomegalovirus (CMV) from human milk, Thes e factors included the gangliosides GM1, 2 and 3, sialyl-lactose, chondroit in sulphates A, B and C, prostaglandins E2 and F2 alpha, monolaurin, vitami n A and the protein lactoferrin, All were tested for their ability to inhib it growth of the viruses in cell culture. Human milk was also tested for an tiviral activity against these viruses. Only vitamin A, monolaurin and lact oferrin inhibited the growth of CMV whereas both prostaglandins enhanced th e growth of this virus at least four-fold. CMV infects infants from milk bu t, nevertheless, the milk-borne CMV isolate showed no special resistance to any of the antiviral factors tested. None of the compounds inhibited or en hanced the growth of the rhinoviruses, However, human milk decreased the gr owth of some of the rhinoviruses and specific secretory immunoglobulin A (s IgA) neutralised the virus.