Serratia marcescens, initially considered to be a nonpathogenic saprophyte, and later is shown to be pathogenic to man in states of markedly altered disease resistance, has now been demonstrated to be a distinct pathogenic entity even in a young, healthy individual, as related in this case report concerning the development of the corneal abscess in a 9-year-old healthy child.
Lazachek GW, Boyle GL, Schwartz AL, Leopold IH. Serratia marcescens, an Ocular PathogenNew Considerations. Arch Ophthalmol. 1971;86(5):599-603. doi:10.1001/archopht.1971.01000010601020