Serratia Marcescens

AIM – The aim of the experiment is to determine the relative effectiveness of several anti-microbial substances on developing pathogens. (E. coli)

In this lab, the organism that we have been working with is the bacterium, Serratia marcescens. S. marcescens is a member of the Enterobacteriaceae family, and tends to grow in damp environments. S. marcescens is an ideal bacterium to work with in the lab because it reproduces quicker than other bacterium. This bacterium produces a special pigment called prodigiosin, which is red in color. The prodigiosin pigment is intensified when S. marcescens is grown at higher densities. During our experiment, temperature, pH, salinity concentration and oxygen requirements were tested on S. marcescens to measure their optimal growth and prodigiosin production.

Abstract-The gram-negative bacteria Serratia marcescens has gained attention in recent years for its tendency to cause nosocomial infections in humans, as well as its development of antibiotic resistance. Antibiotic resistance in a bacterium that is harmful to humans can be concerning as it can result in infections that are difficult to treat. In order to find out more about the growing antibiotic resistance of S. marcescens, this experiment used the disc diffusion method to test the susceptibility of S. marcescens to two varieties of antibiotics that were known to have success against some gram-negative bacterium: streptomycin and ampicillin. These antibiotics were, respectively, an aminoglycoside and a beta-lactam. The experiment tested which of the two that S. marcescens had developed more of a resistance to. The zones of inhibition of the discs were significantly larger for discs treated with streptomycin compared to discs treated with ampicillin. This led to the conclusion that S. marcescens is less resistant to streptomycin than to ampicillin.

Found in human clinical specimens, water, soil, plants, digestive tract of rodents, and insects (Bergey&Holt, 1994, p.187). When isolated from the blood bags, the highest growth was determined under anaerobic conditions.

Dependent Variable: The color change of the bacteria Serratia Marcescens from red to white and the survival of the bacteria.

I discovered that my unknown organism was Serratia marcescens. This organism is gram negative and bacillus shaped. It is a member of the Enertobacteriae family. This organism appears a red blood like color when it grows on media. It is anaerobic, but can also survive under aerobic conditions. There are some strains of Serratia marcescens that are motile and have flagellum. It is able to produce the enzymes chitinase, lipase, protease, nuclease, and serrawttin. It is a non-endospore forming bacteria, chromogenic, and does not ferment lactose. (Falkiner, 1997)

Bacteria grows by binary fission. The aim of this experiment is to follow the growth of Serratia marcescens in nutrient broth at 37oCby recording the changes in turbidity (cloudiness) by measuring the absorbance of visible light (600 nm) and also to prove that there is an increase in the cell number and not just in mass during the growth. In the experiment we measure the full growth curve of Serratia marcescens by measuring the absorbance at 600nm at every 10 mins. I also determined the viable count at the start and the end of the exponential phase of growth. Using the growth curve I calculated the growth curve and it was 1.2. Using this I found the doubling time which was 34s.

The aim of this investigation was to find out which antiseptics were most effective at preventing the growth of bacteria.

Two years ago I went to an exhibition in Milan titled: “Artemisia: storia di una passione” (“Artemisia: history of a passion”). The exhibition was sponsored by the Assessorato alla Cultura of the Comune of Milano and curated by Roberto Contini and Francesco Solinas, with the scenographic and theatrical work of Emma Dante.

Serratia marcescens is a species of Gram-negative bacteria. S. marcescens is considered as a motile organism and expected to be found in soil, dirt or sterile locations. Potential infections would be caused by would sites, respiratory tract and urinary tract. Its red pigmentation makes it recognizable in this experiment. In this study, it will be plated to grow

Working with serratia marcescens and prodigiosin can be such a normal thing and maybe even routine for scientists or their students but not all care to know the background of its origins and where the pigment comes from. Its obvious that we all notice pigment while experimenting with Serratia marcescens  and its best known for the red coloration itself that is produced through strains in the bacteria all connected to a term, Prodigiosin. Prodigiosin is essentially not manufactured at 37°C, but preferably at temperatures below 30°C. The coloration will not be seen in the strains if the conditions don’t connect. All of the environmental conditions in this experiment were tested at 0, 30, 60, 90, 120, 150, and 180 minutes, wavelengths

Serratia marcescens is a species of rod shaped bacteria, it is abundant in nature and it grows in bright red or pink colonies, preferring damp environments. S. marcescens is a common source of urinary and gastrointestinal infections (Hejazi, 1997). The antibiotic gentamicin functions by irreversibly binding to parts of the bacteria’s ribosome, interrupting protein synthesis and preventing the bacteria from reproducing or functioning. S. marcescens is vulnerable to this type of interference because it is a gram-negative bacteria, meaning it has a thin cell membrane, allowing the gentamicin to more easily enter the cell and bind to its ribosome (Zierhut, 1979). Antibiotic resistance is an issue of vital importance because the development of antibiotics

5) My hypothesis: “The higher the concentration of antiseptic, the more powerful it will be at inhibiting/ killing microorganisms which cause bacterial growth.” This theory supports my result because as you can see the zone of inhibition increases due to the increasing concentration of antiseptic. The higher concentration of antiseptic means it has been less diluted, which means its more stronger than other more diluted concentrations, this high concentration will determine how powerful the antiseptic will be at killing/inhibiting the growth of bacterium, this high concentration of antiseptic will break down the bacterial cell wall, after this process has happened the antiseptic can stop the mutation of the bacteria and inhibit the

Strongyloides stercoralis is a nematode that infects approximately 100 million humans worldwide each year. Infection is endemic in tropical regions.

Why exactly is Artemisia Gentileschi considered an early feminist? Doing a brief search and looking into her artwork, even for a brief amount of time and you quickly see why she was considered so. Her gender as well as the things she went through and experienced in her life heavily influenced Artemisia Gentileschi’s artwork. Some of the more famous and controversial paintings focus on females as being the main protagonist. There is plenty of controversy surrounding the paintings as well, since her father Orazio Gentileschi a painter in his own right trained her. Some of her early paintings are questioned and he is given credit for them.