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Difference between revisions of "Serratia marcescens"

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Antagonism of Serratia marcescens towards Phytophthora parasitica and its effects in promoting the growth of citrus (Braz.J.Microbiol.  vol.37 no.4 SãoPaulo Oct./Dec. 2006)
 
Antagonism of Serratia marcescens towards Phytophthora parasitica and its effects in promoting the growth of citrus (Braz.J.Microbiol.  vol.37 no.4 SãoPaulo Oct./Dec. 2006)
 
Phytophthora parasitica causes serious widespread disease in citrus called gummosis.  
 
Phytophthora parasitica causes serious widespread disease in citrus called gummosis.  
A strain of Serratia marcescens R-35, isolated from citrus (a hybrid between mandarin orange and lemon), suppressed more than 50% of the disease and promoted the growth of the citrus plant.
+
A strain of Serratia marcescens R-35, isolated from citrus (a hybrid between mandarin orange and lemon), suppressed more than 50% of the disease and promoted the growth of the citrus plant.
 
The experiment was done under greenhouse conditions.
 
The experiment was done under greenhouse conditions.
  
  
Kinetic analysis of growth rate, ATP, and pigmentation suggests an energy-spilling function for the pigment prodigiosin of Serratia marcescens. (Haddix PL, Jones S, Patel P, Burnham S, Knights K, Powell JN, LaForm A. )
+
Kinetic analysis of growth rate, ATP, and pigmentation suggests an energy-spilling function for the pigment prodigiosin of Serratia marcescens. (Haddix PL, Jones S, Patel P, Burnham S, Knights K, Powell JN, LaForm A. )
  
 
-Is a kinetic model study relating cell, ATP, and prodigiosin (enzyme creating red pigmentation) concentration  changes for S. marcescens during cultivation in batch culture.  
 
-Is a kinetic model study relating cell, ATP, and prodigiosin (enzyme creating red pigmentation) concentration  changes for S. marcescens during cultivation in batch culture.  

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Serratia marcescens
S. marcescens on an agar plate.
S. marcescens on an agar plate.
Scientific classification
Kingdom: Bacterium
Phylum: Proteobacteria
Class: Gammaproteobacteria
Order: Enterobacteriales
Family: Enterobacteriaceae
Genus: Serratia
Species: S. marcescens
Binomial name
Serratia marcescens
Bizio 1823

Description and significance

Serratia marcescens are gram-negative bacteria which fall under the tribe Klebsielleae and the large family Enterobacteriaceae. It is motile bacteria that are facultative anaerobes. The species, Serratia marcescens is the main pathogen under the genus Serratia. Strains of S marcescens produce prodigiosin, the pigment that gives the bacteria its unique red color. They are rod shaped/ bacillus. It is found in numerous different environments. As a human pathogen, however, it is primarily contracted by hospital patients resulting in urinary and respiratory tract infections. It is also resistant to numerous antibiotics.[1]

Cell Features and Functions

Serratia marcescens are facultative anaerobes, which means they prefer oxygen as a source but can do with out. The red pigment, prodigiosin, is characteristic to the bacteria and is produced by the condensation of an enzyme that forms the pigment. S. marcescens have other distinct features. As opposed to other gram-negative bacteria, they can perform casein hydrolysis; producing metalloproteinases which allow f cell-to-extracellular matrix interaction. For different metabolic process to function S. marcescens also degrade tryptophan and citrate. Citrate is a carbon source for S. marcescens. Researchers have discovered other features of the bacteria, such as adherence and hydrophobicity, and lipopolysaccharide (LPS). In a methyl red test, the bacteria tests negative because it does not perform mixed-acid fermentation. It also produces lactic acid resulting from oxidation and fermentation. Different enzymes have been identified in S. marcescens that contribute to its virulence, such as chitinase, lipase, chloroperoxidase and an extracellular protein, HasA. [2]

Genome structure

The Sanger Institute was funded by the Wellcome Trust, and CNRS, to sequence the genome of Serratia marcescens strain Db11. Dr. Jonathan Ewbank of the Centre d'Immunologie de Marseille Luminy is involved in the sequencing as well. . The genome was completed and consists of a single circular chromosome of 5,113,802 base pairs with a G+C content of 59.51%.(1040779 A; 1522992 C; 1520315 G; 1029716 T; 0 other) The shotgun reads are still available. The database contains 80,227 reads totaling 51.619 Mb and giving a theoretical coverage of 99.99% of the genome. [3]

Ecology and Habitat

S. marcescens are omnipresent. They are mesophilic bacteria that prefer moderate or preferably damp environments. Their optimal temperature is at 38C. Extremely low or high temperature and even pH are lethal to S. marcescens. It can be found in soil, or water, or in an infected host. Ranging from vertebrates, invertebrates, including plants, S. marcescens can infect almost anything. In humans they are mainly found in the urinary and respiratory tract, but any part of the body is susceptible. [4]

Discovery

S. marcescens was discovered in 1819 by Bartolomeo Bizio, an Italian pharmacist from Padua. He named the bacteria after the Italian physicist Giacinto Serrati. He first spotted it on cornmeal mush, polenta. The red color on the mush was S. marcescens. For along time the bacterium was not seen as a harmful pathogen but rather a harmless bacterium to experiment with. In the late 1800’s it became known as an infectious pathogen.[5]

Pathology

S. marcescens is a common cause of infections in hospitals, or nosocomial infections. Transmission could be as simple as shaking a hand. In hospitals they are especially existent in the neonatal unit, or ICU. Also contaminated hospital equipment also be blamed for transmission. Syringes, catheters, solutions and other things may have the bacteria on them and cause transmission. That is why it can be observed in heroin addicts who use syringes. Treatment includes cephalosporins, gentamicin, amikacin. However, resistance to the antibiotic is an innate characteristic, formed from r-factors on the plasmids of the S. marcescens. The bacteria have a resistance to ampicillin, macrolides, and first-generation cephalosporins. Antibiotics used to treat Serratia infection include beta-lactam agents, aminoglycosides and fluoroquinolones and a variety of different resistance mechanisms have been demonstrated.[6] It can cause infection anywhere even in the eye causing conjunctivitis, or keratitis.[7]

Application to Biotechnology

Since the early 1900s, the bacteria was widely used in biotechnology because it was believed to be non-pathogenic. until the 1950s. It was used in experiments to track infection, easily done because of the red pigmentation. It was even used in school experiments. In fact, teachers and scientists commonly used S. marcescens in experiments of microbial transmission and to demonstrate the importance of hand washing. Until the 1950s, S marcescens was considered a harmless saprophyte. S marcescens was then recognized as an opportunistic pathogen in humans, and other organisms. It is still used as a biological marker for the transmission of microbes. In Drosophila research, S. marcescens is commonly used bacteria to cause infections. The S. marcescens can be observed by its distinct color, or plaques. In respects to epidemiological studies of S. marcescens includes is detected using biotyping, bacteriocin typing, phage typing, plasmid analysis, polymerase chain reaction and ribotyping. RAPD- polymerase chain reaction is effective in rapidly monitoring an outbreak and tracing the source of initial infection. [8]

Current Research

Antagonism of Serratia marcescens towards Phytophthora parasitica and its effects in promoting the growth of citrus (Braz.J.Microbiol. vol.37 no.4 SãoPaulo Oct./Dec. 2006) Phytophthora parasitica causes serious widespread disease in citrus called gummosis. A strain of Serratia marcescens R-35, isolated from citrus (a hybrid between mandarin orange and lemon), suppressed more than 50% of the disease and promoted the growth of the citrus plant. The experiment was done under greenhouse conditions.


Kinetic analysis of growth rate, ATP, and pigmentation suggests an energy-spilling function for the pigment prodigiosin of Serratia marcescens. (Haddix PL, Jones S, Patel P, Burnham S, Knights K, Powell JN, LaForm A. )

-Is a kinetic model study relating cell, ATP, and prodigiosin (enzyme creating red pigmentation) concentration changes for S. marcescens during cultivation in batch culture. -Cells were grown in a variety of complex broth media at temperatures which either promoted or essentially prevented pigmentation. -High growth rates were accompanied by large decreases in cellular prodigiosin concentration; low growth rates were associated with rapid pigmentation. Prodigiosin was induced most strongly during limited growth as the population transitioned to stationary phase, suggesting a negative effect of this pigment on biomass production. -Studies with cyanide inhibition of both oxidative phosphorylation and pigment production indicated that rates of biomass and net ATP synthesis were actually higher in the presence of cyanide, further suggesting a negative regulatory role for prodigiosin in cell and energy production under aerobic growth conditions.


References:

  1. http://emedicine.medscape.com/article/228495-overview Basilio J Anía, MD “Serratia” eMedicine. 1 Oct 2009
  2. http://jmm.sgmjournals.org/cgi/content/abstract/46/11/903?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&title=Serratia+marcescens&andorexacttitle=and&andorexacttitleabs=and&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT..[Hejazi, A. ; F. R. Falkiner1 “Serratia marcescens” J Med Microbiology 46 (1997), 903-912; DOI: 10.1099/00222615-46-11-903. April 1, 1997.
  3. http://www.sanger.ac.uk/Projects/S_marcescens/.
  4. http://www.ncbi.nlm.nih.gov/sites/entrez?db=genomeprj&cmd=search&term=Serratia%20marcescens
  5. http://www.ncbi.nlm.nih.gov/pubmed/9368530
  6. PMID: 9368530 [PubMed - indexed for MEDLINE] http://www.ncbi.nlm.nih.gov/pubmed/9368530
  7. http://prod.hopkins-abxguide.org/pathogens/bacteria/full_serratia_species.html
  8. http://microbezoo.commtechlab.msu.edu/zoo/microbes/serratia.html. "The Miracle Microbe: Serratia marcescens." Digital Learning Center for Microbial Ecology. 1999. Michigan State Univeristy, National Science Foundation. 12 May 2009
  • PMID: 9368530 [PubMed - indexed for MEDLINE]

http://www.ncbi.nlm.nih.gov/pubmed/9368530