According to him, coercion is the intention to interfere in the freedom of an individual. Serratia marcescens was first thought to be harmless (non-pathogenic)… This indicates the organism is a motile, anaerobe that ferments glucose with no gas. (boydii, dysenteriae, flexneri) Shigella sonnei … optimal growth conditions: temperatures, pH, aerotolerance Table 1: Physiological & Biochemical Test Results – #1 Serratia marcescens Test, Crystal violet, iodine, alcohol, safranin. With the color contrast, the separation of organisms is certain and pure cultures can be grown. This is determined using a Gram Stain process. When the Gram stain was inconclusive for this bacterium, it was sensible to use other tests to positively identify it. Each organism was used to inoculate a liquid nutrient broth which was then incubated at 37◦C for 18-24 hours. December 7, ... test, decarboxylation, deamination,Bile Esculin, Starch hydrolysis, Urea, Casein, Gelating hydrolysis, DNA hydrolysis, Lipid hydrolysis, SIM and any other test you consider appropriate in the identification of your organism. Mannitol, EMB, MacConkey, Blood Agar, OF-Glucose, Phenol Red Carbohydrate fermentation, MR-VP, Nitrogen reduction, Catalase, Oxidase, Citrate This simple sugars then pass through various mechanism to yield ATP molecules. They need positive encouragement, and this can not be in negative assumptions. The starch agar plate was inoculated with isolates #1 and #2 using a sterile loop. San Francisco, et al: Daryl Fox. (2005, Aug). Gelatin hydrolysis test is helpful in identifying and differentiating species of Bacillus, Clostridium, Proteus, Pseudomonas, and Serratia. Serratia marcescens (S. marcescens) is a gram-negative bacillus that occurs naturally in soil and water and produces a red pigment at room temperature. Each result was consistent with expected results for B. cereus. It is associated with urinary and respiratory infections, endocarditis, osteomyelitis, septicemia, wound infections, eye infections, and meningitis. Baltimore: The Williams & Wikins Company. Description of laboratory tests (experiments) specific to the suspected organism including: Both isolates were tested for oxidase by adding p-aminodi-methlyaniline oxalate to colonies grown on a medium, and neither had a reaction, indicating that they do not produce cytochrome oxidase. Observations were made at 15 minutes. Description of symptoms and signs of the patient As with many other . So remember, if you meet ... ... on population decline, as the Australias population growth rate remained positive. Serratia marcescens is a species of rod-shaped gram-negative bacteria in the family Enterobacteriaceae. Black, J., & Black, L. (2008). Gram reaction, A clear zone around the colonies demonstrates a positive test after the addition of 1N HCl. Prevention includes refrigerating rice products right away instead of cooling before putting in the refrigerator. Few aberrant results were obtained in the bacterial strains isolated. Bacterial cell walls are made up of polysaccharide chains linked to amino acids. It is necessary to first separate the two organisms by inoculating a nutrient agar plate using the streak-plate method. Starch hydrolysis test: starch agar is used to determine if bacteria produce the enzyme amylase which breaks down starch, causing hydrolysis. The culture was shaken, then immediately 10 drops of Barritt’s reagent B was added and it was shaken again. Cover Sheet I certify that the writing in this assignment is my individual work and is my sole intellectual property. IS serratia marcescens negative for a starch hydrolysis test? Author: Mark Cooper Jr. In liquid media, the cells are short rods known as swimmers, … This indicates lysis of red blood cells occurred, which is beta-hemolysis. by admin March 5, 2016, 12:26 am 1.8k Views. For the Voges-Proskauer test, 10 drops of Barritt’s reagent A is added to the second tube of medium. 4. Most people are unaware that uncooked rice is potentially a hazardous food since B. cereus can be present and actually survive cooking. [23] Serratia was later renamed Monas prodigiosus and Bacillus prodigiosus before Bizio's original name was restored in the 1920s.[22]. RESULTS Based on the colony morphology, physical and biochemical test, Serratia sp is a gram negative, rod shaped bacteria and grows under room temperature. Gram Stain: The organisms must first be identified as gram-negative or gram-positive. Triple Sugar-Iron (TSI) agar test: This test was used for both isolates, #1 and #2, and is designed to differentiate based on differences in carbohydrate fermentation patterns and hydrogen sulfide production. Here you can order a professional work. Serratia marcescens. (Find a price that suits your requirements), The Essay on Biology and Population Growth Rate, The Term Paper on Identifying Unknown Bacteria, The Essay on Gram Positive And Gram Negative Bacteria, The Essay on Positive And Negative Effects Of Slavery In Cultural And Social Terms For The Typical Southerner, The Essay on Negative Liberty Positive Freedom Coercion. As expected, isolate #1 bubbled nicely, indicating the presence of catalase and allowing the conclusion that #1 is a facultative anaerobe instead of a strict anaerobe. The second organism, Serratia marcescens, might be present in the vomit due to the same contaminated food; however it could also have been in the intestines of the patient, without causing a problem. Subsequent tests and procedures are described elsewhere in this report. Disclaimer: This work has been submitted by a student. Most Serratia strains can grow from pH 5 to 9 and are among the bacteria that can grow in foods with water activity of 0.91–0.95. Looks like coccobacilli. Observation showed #1 was red on the slant but yellow in the butt of the tube. There is also a diarrheal type of food poisoning due to B. cereus, however in this instance the illness presents only with vomiting. To what extent do you agree or disagree? Serratia marcescens is an opportunistic gram-negative pathogen and one of the main Enterobacteriaceae responsible for hospital-acquired infections. Once it is determined to be a gram-negative rod, the oxidase test being negative leads to doing a methyl red test. They also are able to grow in foods from low redox potential (Eh) of −200 mV (meat) to high redox potential of +300 mV (fruit juice). This is further indication that #2 is gram-positive, while #1 is most likely gram-negative. A human pathogen, S. marcescens is involved in hospital-acquired infections (HAIs), particularly catheter-associated bacteremia, urinary tract infections and wound infections, and is responsible for 1.4% of HAI cases in the United States. Serratia marcescens & Bacillus cereus Report. Pseudomonas aeruginosa and Serratia marcescens with clear transparent zones while most other organisms failed to produceanyhydrolysis orat the most, hazy zones only. It also differentiates lactose-fermenting bacteria from non-lactose-fermenting bacteria. Date: 10/24/12 Lab Instructor: Katherine Hovanes Lab Section # 12 Population Ecology Experiment Background: Phosphate is an abiotic factor; therefore, it is a nonliving factor that ... MacConkey agar: MacConkey agar is both a differential and selective medium used to select for gram-negative bacteria. After inoculation, the plate was incubated at 37¦C all day and night. Because of this, the illness often goes unreported. 4. Organism #2 was obviously a gram-positive rod from the very first Gram stain. may not apply to your organism. Cappuccino, J. G., & Sherman, N. (2008). To differentiate organism based on their α- amylase enzyme activity serratia marcescens. For the methyl red test, five drops of pH indicator methyl red is added to one of the tubes of medium. The post Serratia marcescens first appeared on COMPLIANT PAPERS. Bergey’s Manual of Determinative Bacteriology (Seventh ed.). For microorganisms to utilize starch, it should first hydrolysis it since it is too huge to go through the cell layer. Microbiology: Principles and Explorations (7th ed.). Oxidase enzymes play an important role in electron transport during aerobic respiration. Post author By a b; ... Starch hydrolysis, Urea, Casein, Gelating hydrolysis, DNA hydrolysis, Lipid hydrolysis, SIM and any other test you consider appropriate in the identification of your organism. This is another contradiction of expected results and is contradicted in the next test. Without indicator. Observation shows there is a bright red growth but no change in the appearance of the medium. enterobacteriaceae, unknown tested positive for the presence of catalase but negative for the presence of oxidase and starch hydrolysis. environmental species). Phenylethyl alcohol agar (PEA): PEA is a selective medium which is used to identify gram-positive bacterium. Certainly, the disadvantages of imported food outweigh the advantages. At the same time, plant cell walls are made up of cellulose, which contains no amino acids. Serratia marcescens is a motile,short rod-shaped, Gram-negative, facultative anaerobe bacterium, classified as an opportunistic pathogen. (T. W. Firm, Producer) Retrieved May 10, 2009, from Serratia- Marcescens.org: http://www.serratia-marcescens.org/index.cfm Katelijne Dierick, e. a. After inoculation, the plate was incubated at 37 C for 24 hours. Good hygiene is always important, but be aware that Bacillus cereus can be in uncooked rice, dried beans, cereals and spices, and this bacterium is resistant to heat. The plate was then flooded with Gram’s iodine which reacts with starch to turn purple-blue. Upon observing #2, the entire medium was yellow with a small amount of liquid at the bottom of the slant, and slight motility in the stab pathway. There being no growth and no change in appearance of the medium for either organism, this indicates there was no mannitol fermentation and they do not tolerate salt. morphology, Due to this, and because S. marcescens produces a reddish-orange tripyrrole pigment called prodigiosin, it may cause staining of the teeth. Serratia marcescens is a species of rod-shaped gram-negative bacteria in the family Enterobacteriaceae. Oxidase test: This test is designed to distinguish among groups of bacteria based on cytochrome oxidase activity. This enzyme catalyses the following chemical reaction. Serratia marcescens also had a high protease yield in basal medium amended with rice bran. Catalase test: This test is to determine whether the isolates can produce catalase in order to degrade toxic hydrogen peroxide. Jefferson City: John Wiley & Sons, Inc. Bizio 1819. As is more common specifically to . ... it’s an organism that can ferment lactose MacConkey media No growth for either bacteria Negative for both bacteria Phenylethyl alcohol Agar To select for gram positive Cocci PEA ... ... of society to think about the negative assumptions about youth rather than the positive ones. Bacterium #2 was inoculated onto a blood agar plate using a sterile loop. There was heavy gray growth on this enriched medium. Starch hydrolysis test: Starch agar can be used to determine in the event that bacteria generate the chemical amylase which will breaks down starch, causing hydrolysis. It was then observed that there was heavy growth on the plate with a clear ring around the colonies. Wecon-cludefromthisstudythatthehydrolysisofcaseinis a valuable differential aid in the identification of Serratia marcescens. The plate was incubated at 37◦C for 24 hours. The results of the biochemical tests confirmed that the isolate I-3 was that of Serratia marcescens . Discussion/conclusion with the antimicrobial method (chemical/physical) treatment for the infection/disease or mitigation (if you have an Retrieved May 10, 2009, from Wikipedia: The Free Encyclopedia: http://en.wikipedia.org/ Alexander, S., & Strete, D. (2001). Starch Hydrolysis Several drops of Gram’s iodine were added to the bacterial streaks on the starch agar plate. The medium used is a TSI slant. Any bacteria that seemed to repel the iodine, creating a clear area around the streak, were considered to have gone through starch hydrolysis (positive outcome). After blotting carefully, the slide is placed on a microscope and focused on the organism at the lowest magnification, progressing to the highest magnification with oil immersion. The Biochemical identification of Serratia marcescens showed that bacteria were Gram –ve, Rod, Catalase positive, oxidase negative, lactose non- fermenter, motile, ... Bacillus subtilis is positive for starch hydrolysis (pictured below on the left). #1 was negative for starch hydrolysis, not producing amylase. After inoculation, the plate was incubated at 37◦C for 18-24 hours. Table 3 Population Change in Australia, ... in Australia, emphasizing the importance of studying population growth. Reagent: Hydrochloric acid (1mol/L) only when DNase agar without an indicator is used Others: Inoculating loop, Bunsen burner Procedure of DNase (DNA hydrolysis test) Dry the surface of agar plates before use.Each plate may be divided into sections by drawing lines on the bottom of the plate. Image Source: Bailey and Scott’s Diagnostic Microbiology. Differential/ Selective media, Indicates this is a gram-negative bacterium, Indicates that pyruvic acid was metabolized to neutral end products Voges- Proskauer, Red color on slant, yellow in bottom, movement away from stab site Motile, Indicates presence of catalase; facultative anaerobe, Table 2: Physiological & Biochemical Test Results – #2 Bacillus cereus Test. Retrieved May 10, 2009, from Pub Med Central: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1233987 Nutrition, C. f. (2009, April 9). They are gram -ve, catalase positive, oxidase negative, MR negative and VP positive bacteria.