Opportunistic Infections Caused by Serratia marcescens: Difference between revisions

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<br>Introduce the topic of your paperWhat microorganisms are of interest? Habitat? Applications for medicine and/or environment?<br>
<br>Serratia marcescens, a rod-shaped gram-negative bacterium, is a member of the Enterobacteriaceae family.  Ubiquitous in nature, S. marcescens is found on dead organic material, while some inhabit soil, water, air, plants, animals, or food.  In particular, food sources that provide a nutrient rich environment include starchy variants (Hejazi and Falkiner 1997).  Some of these bacteria can be identified in ecological niches by their red pigment, prodigiosin (2-methyl-3-penty-6-methoxyprodigiosin), which can resemble blood (cite).  Since this pigment is easily recognized in certain strains due to its red coloring, it has been extensively used as a biological marker (Perez). Also, prodigiosin has antibacterial, antifungal, antiprotozoan, and immunosuppressant activity.  Environmental signals such as temperature, phosphate limitation, and medium components regulate prodigiosin production.  Prodigiosin is not the only secreted product, many more include protease, nucleases, lipase, chitinase, the biosurfactant serrawettin, and hemolysin (Morohoshi)
Although, S. marcescens was considered to be an innocuous, non-pathogenic organism, over the last two decades they have become an opportunist pathogen causing nosocomial infections (Hejazi). A broad range of hospital-acquired infections include respiratory tract infections, urinary tract infections (UTI), septicaemia, meningitis, pneumonia, conjunctivitis wound and eye infections, osteomyelitis, keratoconjunctivitis, keratitis, endophthalmitis and endocarditis (Hejazi, Matsuo, Castelli, Kida, Koh).  S. marcescens are also capable of causing disease in a diverse group of organisms including animals, coral, insects, and plants (Hejazi and Coulthurst)
Many problems arise in treating nosocomial infections because of resistance to a variety of antibiotics, such as cephalosporins, aztreonam, imipenem, cefotaxime, and ceftazidime (Kumar, Mammeri)Therefore, novel treatment techniques are in need to eliminate infections without overuse of the antibiotic (Morohoshi).
Rare cases of S. marcescens include nonhospital associated infections. These cases are linked to patients with immune deficiencies or chronic debilitating diseases. Human medicine, outside of hospital settings, can involve intravenous drug use that can also spread S. marcescens. (Perez).
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==Section 1==
==Section 1==

Revision as of 00:55, 25 April 2011

Introduction

Electron micrograph of the Ebola Zaire virus. This was the first photo ever taken of the virus, on 10/13/1976. By Dr. F.A. Murphy, now at U.C. Davis, then at the CDC.


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Legend/credit: Electron micrograph of the Ebola Zaire virus. This was the first photo ever taken of the virus, on 10/13/1976. By Dr. F.A. Murphy, now at U.C. Davis, then at the CDC.
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Serratia marcescens, a rod-shaped gram-negative bacterium, is a member of the Enterobacteriaceae family. Ubiquitous in nature, S. marcescens is found on dead organic material, while some inhabit soil, water, air, plants, animals, or food. In particular, food sources that provide a nutrient rich environment include starchy variants (Hejazi and Falkiner 1997). Some of these bacteria can be identified in ecological niches by their red pigment, prodigiosin (2-methyl-3-penty-6-methoxyprodigiosin), which can resemble blood (cite). Since this pigment is easily recognized in certain strains due to its red coloring, it has been extensively used as a biological marker (Perez). Also, prodigiosin has antibacterial, antifungal, antiprotozoan, and immunosuppressant activity. Environmental signals such as temperature, phosphate limitation, and medium components regulate prodigiosin production. Prodigiosin is not the only secreted product, many more include protease, nucleases, lipase, chitinase, the biosurfactant serrawettin, and hemolysin (Morohoshi) Although, S. marcescens was considered to be an innocuous, non-pathogenic organism, over the last two decades they have become an opportunist pathogen causing nosocomial infections (Hejazi). A broad range of hospital-acquired infections include respiratory tract infections, urinary tract infections (UTI), septicaemia, meningitis, pneumonia, conjunctivitis wound and eye infections, osteomyelitis, keratoconjunctivitis, keratitis, endophthalmitis and endocarditis (Hejazi, Matsuo, Castelli, Kida, Koh). S. marcescens are also capable of causing disease in a diverse group of organisms including animals, coral, insects, and plants (Hejazi and Coulthurst) Many problems arise in treating nosocomial infections because of resistance to a variety of antibiotics, such as cephalosporins, aztreonam, imipenem, cefotaxime, and ceftazidime (Kumar, Mammeri). Therefore, novel treatment techniques are in need to eliminate infections without overuse of the antibiotic (Morohoshi). Rare cases of S. marcescens include nonhospital associated infections. These cases are linked to patients with immune deficiencies or chronic debilitating diseases. Human medicine, outside of hospital settings, can involve intravenous drug use that can also spread S. marcescens. (Perez).

Section 1


Include some current research, with at least one figure showing data.

Section 2


Include some current research, with at least one figure showing data.

Section 3


Include some current research, with at least one figure showing data.

Conclusion


Overall text length at least 3,000 words, with at least 3 figures.

References

[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.

Edited by student of Joan Slonczewski for BIOL 238 Microbiology, 2011, Kenyon College.