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Serratia marcescens is a species of Gram-negative bacteria in the family Enterobacteriaceae. A human pathogen, S. marcescens is involved in nosocomial infections, particularly urinary tract infections and wound infections. }}
S. marcescens is a rod shaped, motile organism and can grow in temperatures ranging from 5–40°C Celsius and in pH levels ranging from 5 to 9. *
Due to its ubiquitous presence in the environment, and its preference for damp conditions, S. marcescens is commonly found growing in bathrooms (especially on tile grout), where it manifests as a pink discoloration. Once established, complete eradication of the organism is often difficult, but can be accomplished by application of a bleach-based disinfectant.
Pathogenesis
S. marcescens can cause conjunctivitis, keratitis, endophthalmitis, and tear duct infections. It is not uncommon in the respiratory and urinary tracts of adults and the gastrointestinal system of children. 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.
In coral, S. marcescens is the cause of the disease known as White pox.
Historical
In the 1950s S. marcescens was erroneously believed to be non-pathogenic and its reddish coloration was used in school experiments to track infections. It has also been used as a simulant in biological warfare tests by the United States Military. On September 26 and 27, 1950, the United States Navy conducted a secret experiment named "Operation Sea-Spray" in which an aerosolized cloud of S. marcescens was sprayed over urban areas of the inland San Francisco Bay Area in California from balloons lofted from Navy vessels standing just off the coast to gauge the effectiveness of a similar biological attack. Although the Navy later claimed the bacteria were harmless, beginning on September 29 eleven patients at a local hospital developed very rare, serious S. marcescens infections and one of these individuals, Edward J. Nevin, died.,
Since 1950, S. marcescens has steadily increased as a cause of human infection, with many strains resistant to multiple antibiotics. The first indications of problems with the influenza vaccine produced by Chiron Corporation in 2004 involved S. marcescens contamination.
Because of its red pigmentation, caused by expression of the pigment prodigiosin, }} and its ability to grow on bread, S. marcescens has been evoked as a naturalistic explanation of Medieval accounts of the "miraculous" appearance of blood on the Eucharist that led to Pope Urban IV instituting the Feast of Corpus Christi in 1264. This followed celebration of a Mass at Bolsena in 1263, led by a Bohemian priest who had doubts concerning transubstantiation, or the turning of bread and wine into the body and blood of Christ during the Mass. During the Mass, the eucharist appeared to bleed and each time the priest wiped away the blood, more would appear. This event is celebrated in a fresco in the Pontifical Palace in the Vatican City, painted by Raphael.
References
External links
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"Serratia marcescens"