Abstract: Gliotoxin, an epipolythiodioxopiperazine, is a fungal metabolite that causes genomic DNA degradation preferentially in certain blood cell types including T lymphocytes and macrophages. Methods: To start isolating the bacterium, I used a sterile swab wet with deionized water provided by the lab to pick up bacteria from the shower drain. The Gentamicin, Cefoperazone, Vancomycin, Tobramycin, Amikacin, Trimethoprim, and Cefazdin antibiotics showed obvious susceptibility, with most of them having enormous rings of 50 to 52 millimeters while the threshold for resistance is only 15 millimeters. DNA release from the cell is coupled with adsorption of DNA onto a silica spin-column . This can occur due to the presence of a reduced number of proteins that can bind to penicillin. Because of their diversity, there are a variety of biochemical tests that are used by laboratories to identify the Gram-positive cocci. Microbiome 2(27). M. luteus played an important part in Flemings discovery of Lysozyme which is the bodys natural antibiotic. Retrieved 22:17, April 16, 2019, from https://en.wikipedia.org/w/index.php?title=Staphylococcus_aureus&oldid=890960280, Your email address will not be published. In the presence of atmospheric oxygen, the oxidase enzyme reacts with the oxidase reagent and cytochrome C to form the coloured compound, indophenol indicated as blue or purplish-blue colouration on the disc after the introduction of the bacterial colony on the disc. It shows that the sample contains bacteria from the Terrabacteria group. Micrococcus spp. We found this to be true because the filter paper turned blue, which showed that the species has the cytochrome c oxidase enzyme. M. luteus is the majority of reads on the species level. In conclusion, some of my results were inconclusive and conflicting. Micrococcus Luteus Oxidase Test: The microdase test, also known as modified oxidase test is a rapid test to differentiate Staphylococcus from Micrococcus which are Gram-positive cocci possessing catalase enzymes. As mentioned, the type of hemolytic reaction produced on sBAP is a major clue toward the identification of the genus. If acid is produced, the pH indicator will turn yellow. The confidence on that reading is decently confident, evidenced by the blue coloring. The oxidase test tests to see if the microbe contains cytochrome c oxidase. Micrococcus, genus of spherical bacteria in the family Micrococcaceae that is widely disseminated in nature.
An interesting remaining family member, Microoccus antarcticus, was isolated from Antarctica, and is capable of growing at 4C. Biochemical 1- Catalase (+ve) 2- Coagulase (-ve) Production of bubbles indicates a positive reaction.
Most of the bacterium in the gram stains were gram negative, but a significant amount, about twenty percent, showed up as gram positive. Ans: Although it is a harmless saprophyte, Micrococcus luteus can act as an opportunistic pathogen. (2019, April 4). Colony morphology, the elucidation of the characteristics of the growth of the bacterium on agar medium, in most cases trypticase soy agar containing 5% sheep blood (sBAP). This is termed alpha () hemolysis and results in a greenish color surrounding the colony. The Micrococcus genus is known to be found on dust particles, in water, on skin and skin glands in vertebrates, and some species can be found in milk. They are fairly ubiquitous in the environment, and are small (0.5 to 3.5 micrometers in diameter) and non-motile. The catalase test also indicated that the microbe does not have catalase, despite the metagenomic binning test suggesting it. Micrococcus lutues are Gram positive cocci that are 0.5 to 3.5 m in diameter and arranged in tetrads or irregular clusters. Abstract Micrococcus luteus IFO 3333 cells, both treated with chemical reagents and non-treated, were observed with a scanning electron microscope (SEM). The previous classification of these organisms was much simpler; however, with the use of more advanced genetic sequencing methods, these gram-positive cocci have expanded into 4 separate families and their associated genera. The colony forms as a yellow, shiny round blob. Gram Stain:Gram-positive cocci, arranged in clusters that differ from Staphylococcus. Oral microbial flora of reptiles includes bacteria from Proteus, Porphyromonas, Micrococcus, Salmonella and Staphylococcus genera 5,8,15. luteus is capable of surviving in environments The microbiome of the nose. Other Micrococcus isolates produce various useful products, such as long-chain aliphatic hydrocarbons for lubricating oils. The GC content of the DNA ranges from about 65 to 75 mol%. The modified oxidase reagent is prepared as tetramethyl-p-phenylenediamine in certified grade dimethyl sulfoxide. This suggests that some of the Micrococcus species on the basis of ribosomal RNA analysis eventually can be re-classified into other microbial genera. Micrococcus is a genus of bacteria that is present in the Micrococcaceae family. Another set of tests that I performed were physiological tests, including testing for oxygen class with fluid thyoglycate, checking for catalase using hydrogen peroxide, checking for cytochrome c oxidase using oxidase test strips, and using an API 20 E test strip to test for various different physiological traits such as Sulphur reduction, which had 20 different tests. The PYRA, PAL, LAP, RIB, ARA, MAN, and TRE tests came up as positive. Care must be taken when using a sample of organism acquired from a sBAP since erythrocytes also produce catalase. The typical microscopic morphology of the Gram-positive cocci when using the Grams stain is represented in these three images. The name of the genus is also called " Germanized " is written as Micrococcus. The identification of three different biovars within the species M. luteus has the advantage that the three groups can be differentiated without nomenclatural changes having to be introduced. Results of the biochemical tests demonstrated that the M. luteus and M. varians strains could be distinguished by their actions on glucose and nitrate reduction (Table I). Intro: Microbes are everywhere, even in the most extreme environments and conditions. Staphylococci are either producers of the enzyme coagulase or non-producers. The sample was then sequenced using the Illumina MiSeq technology in UAFs DNA Core Lab. The colony took 16 days to be purified. Micrococcus luteus is coagulase negative, bacitracin susceptible, and forms bright yellow colonies on nutrient agar. Hybridization studies show that there is no close genetic relationship between the species of Micrococcus bacteria. In the last control, agar-agar was inoculated with 1 mL of M. luteus washed live cells and incubated for 24 h at 37 C. The laboratory assay is performed by mixing a sample of the bacterial colony with a drop(s) of hydrogen peroxide placed on a microscope slide. Like all Staphylococci, S. saprophyticus is also clustering Gram-positive cocci, nonmotile, non-spore-forming, and . Notice that beta-hemolysis results in a total lysis or clearing of the agar in the area of colony growth. Colonies typically have a lemon-yellow pigment. It is essential for differentiating catalase-positive Micrococcaceae from catalase-negative Streptococcaceae. Its genome has a high G + C content. Micrococci can grow well in environments with little water or high salt concentrations, including sportswear that is made with synthetic fabrics. Coagulase production is used as a virulence factor by the organism. If an organism is capable of fermenting the sugar glucose, then acidic byproducts are formed and the pH indicator turns yellow. Gram Staining. Micrococcus luteus is another gram-positive coccus that also is catalase positive. About half of the Micrococcus luteus gram stain was found to carry plasmids of about one to 100MDa in size. These include the slide or drop catalase test, the tube method, the semiquantitative catalase for the identification of Mycobacterium, M. luteus played an important part in Flemings discovery of, A rare case of prosthetic valve endocarditis is caused by Micrococcus luteus, it is described and compared with the few cases that are reported in the literature, as well as the clinical features, microbiological profile, therapy, and prognosis of common prosthetic valve endocarditis. Due to the thick structure of the bacterial cell wall, Gram-positive cocci retain the primary Grams stain, Crystal Violet. Micrococci can often carry plasmids that provide the organism with useful traits. . The API test strips lack of results suggests that the I used the wrong test strip, I probably needed to use the Staph test instead of the Strep test, because the Strep test is for when Catalase is absent, but there could have been catalase present. Organisms commonly found on the body include Micrococcus, Staphylococcus, and Corynebacterium species (Dermnet New Zeland). 1. The EMB plate is also selective for gram-negative bacteria which is probably why the bacteria didnt grow on it. The API 20 Strep test I used came up with no conclusive results. Biochemical Test Chart (You will not fill in every blank in this chart.) 91 988-660-2456 (Mon-Sun: 9am - 11pm IST), Want to read offline? They grow in circular, entire, convex, and usually non-pigmented or cream white colonies with diameters of approximately 4 mm after 2-3 days on the plate at 37C. The microdase test, also known as modified oxidase test is a rapid test to differentiate Staphylococcus from Micrococcus which are Gram-positive cocci possessing catalase enzymes. They usually can occur in the irregular clusters, tetrads, and in pairs, where the individual cells are about one to 1.8 mm in diameter and these are usually non-motile and non-spore-forming in nature. This can occur due to the presence of a reduced number of, Most of the Micrococcus infections are discovered through the process of elimination along with the presence of the abundant Micrococcus tetrads in the lesions or cysts. Micrococcus luteus growth on nutrient agar is bright mustard-yellow colonies as shown above image. Recent reports, however, confirm that micrococci may be associated with human infections, particularly in immunosuppressed patients. The genome of the Micrococcus is rich in guanine and cytosine, they typically exhibit about 65 to 75% GC-content. All of these are described in the lab 6 handout and were kept in the incubator at 38 degrees Celsius. The differentiation is based on the detection of the oxidase enzymes. //
The antibiotic resistance test showed only minor resistance to the antibiotic Oxacillin, which is likely due to a chance inheritance in the population or complete chance because of the weak strength. Micrococcus is a spherical bacterium found on dead or decaying organic matter while Staphylococcus is a gram-positive bacterial genus that produces a bunch of grape-like bacterial clusters. M. luteus oxidize carbohydrates to form carbon dioxide and water, and it does not produce acid from the glucose as well as it does not make arginine dihydrolase or b-galactosidase. Micrococcus luteus ( M. luteus ), is a Gram-positive bacteria, 0.05 to 3.5 microns in diameter, that is most commonly found in mucous membranes such as the nasal cavities, the upper respiratory tract, and the lining of the mouth. M. lylae can be distinguished from the closely related species Micrococcus luteus by lysozyme susceptibility, genetic composition, and the type of cell-wall peptidoglycan. Micrococcus species are oxidase-positive, which can be used to distinguish them from other bacteria like most Staphylococcus species, which are generally oxidase-negative. Micrococcus Public Health Agency of Canada., Public Health England. Filter paper disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride (oxidase reagent) in dimethyl sulfoxide (DMSO) are used. This microbe forms large, round colonies. //
Hemolysis is the lysis of the sheep erythrocytes within the agar by bacterial toxins (hemolysins) that are produced by the different genera of Gram-positive cocci. The metabolic pathways required for biomass production in silico were determined based on earlier models of actinobacteria. Basics of Differentiation of Gram Positive Cocci, The Journal of Applied Laboratory Medicine, Challenges in Blood Group Alloantibody Detection, Clinical Applications of Complement Testing, Collecting Blood from Patients with Vascular Lines, Diagnosis of Syphilis Using the Reverse Algorithm, Liquid Chromatography LC Basics and Separation Techniques, Liquid Chromatography Separation Mechanisms, Optimal Reporting of Diagnostic Accuracy Studies, Pharmacogenetics for Drug Hypersensitivity Reactions, Sensitivity Specificity and Predictive Values in Diagnostic Testing, Transfusion Support in Hematopoietic Cell Transplant, Clinical Chemistry Guide to Scientific Writing, Commission on Accreditation in Clinical Chemistry. They are also catalase-positive and often weakly oxidase-positive ( modified oxidase test positive). They are likely involved in the biodegradation of many other environmental pollutants or detoxification. M. luteus can also cause septic shocks in immuno-compromised people. After you have cultivated your organism on agar media, the next step is the microscopic examination. This is a test for aerobic (able to use oxygen) catalase-positive bacteria such as Staphylococcus and Micrococcus. Characteristics. Other articles where Micrococcus luteus is discussed: Micrococcus: found in milk, such as M. luteus, M. varians, and M. freudenreichii, are sometimes referred to as milk micrococci and can result in spoilage of milk products. The catalase and the oxidase tests came up negative, because the catalase test did not form bubbles, and the oxidase test did not see a color change. The conflicting results of the metagenome binning and the catalase test influenced this mistake. A rare case of prosthetic valve endocarditis is caused by Micrococcus luteus, it is described and compared with the few cases that are reported in the literature, as well as the clinical features, microbiological profile, therapy, and prognosis of common prosthetic valve endocarditis. A very important test in the categorization of the staphylococci is the coagulase test. It is an aerobic exopolysaccharide producing bacteria that may be found on the skin, mouth and sometimes in the throat of mammals 13,14. Only the Micrococcus luteus species contained cytochrome c oxidase. Each genus lends itself to a separate tutorial. To identify our isolate after obtaining the pure culture, we performed many different tests. They are seldom motile and are non-sporing. Micrococcus luteus in tetrads arrangement.
Based on the place of origin of the bacterium that I isolated, I hypothesize that it will either be one of the above bacterium or a similar water loving organism, likely one that also forms a biofilm. Micrococcus luteus biochemical test result. The gram stain of this microbe showed that it is gram positive because it stained purple. They can be found in boiling hot springs; they can be found in frigid waters in the artic. Next, we see an image of a mixed bacterial culture which displays the white, creamy, non- hemolytic colonies of Staphylococcus epidermidis mixed with the golden, hemolytic colonies of Staphylococcus aureus. Bacteria Detail., The Editors of Encyclopdia Britannica. Your email address will not be published. Alpha-hemolytic colonies often assume a greenish hue. Reduction of O2 produces superoxide radicals and hydrogen peroxide, or the hydroxyl radical. Micrococcus luteus is generally harmless but can become an opportunistic pathogen in immunocompromised people or those with indwelling catheters. This lines up with M. luteus resistances from the tests. A very important test in the categorization of the staphylococci is the coagulase test. M. luteus present on the human skin can transform compounds present in sweat into compounds with an unpleasant odour. The configurations are the result of the plane of cellular division exhibited by the organism. all 3 tests done w/SIM deeps just add Kovac's reagent for Indole test Alcaligenes faecalis (left) - . Micrococcus Luteus Oxidase Test: The microdase test, also known as modified oxidase test is a rapid test to differentiate Staphylococcus from Micrococcus which are Gram-positive cocci possessing catalase enzymes. In this presentation, we will discuss the fundamentals of the primary identification of those microorganisms that are members of four main families of Gram-positive cocci, the Micrococcaceae, the Staphylococcaceae, the Streptococcaceae, and the Enterococcaceae.