Serratia Marcescens - Pathogenesis

Pathogenesis

S. marcescens can cause infection in several sites, including the urinary tract, respiratory tract, wounds, and the eye, where it may cause conjunctivitis, keratitis, endophthalmitis, and tear duct infections. It is also a rare cause of endocarditis and osteomyelitis (particularly in people who use intravenous drugs recreationally), pneumonia, and meningitis. Most S. marcescens strains are resistant to several antibiotics because of the presence of R-factors, which are a type of plasmid that carry one or more genes that encode resistance; all are considered intrinsically resistant to ampicillin, macrolides, and first-generation cephalosporins (such as cephalexin).

In elkhorn coral, S. marcescens is the cause of the disease known as white pox disease. In silkworms, it sometimes occurs as a secondary pathogen in viral flacherie disease.

Also in Drosophila research laboratories, infection with S. marcescens is common. It manifests itself as a pink discolouration or plaque in or on larvae, pupae, or the usually starch and sugar-based food (especially when improperly prepared).