Many members of the genus have been reclassified into other genera. This is designated as beta ()-hemolysis. This fits well with where I sampled my bacterium from, as a shower drain is a place where both dust and water would accumulate, along with residues of skin glands from showering. The majority of staphylococcal species produce non-pigmented colonies with smooth margins, as opposed to the important pathogen, Staphylococcus aureus, which produces the characteristic colonies seen here. In order to determine physiological characteristics of the culture such as cell shape, arrangement, and whether it was gram positive or negative, which helps determine the cell wall type of the microbe, I performed a gram stain. In Wikipedia, The Free Encyclopedia. Typical colonies are often described as gray to white, moist or glistening. Streptococcus spp. M. luteus oxidizes carbohydrates to CO2 and water, and it does not produce acid from glucose as well as it does not make arginine dihydrolase or b-galactosidase. Its genome has a high G + C content. M. luteus is found in the soil, dust, water, and human skin flora. The skin infections or chronic cutaneous infections that are caused can result in pruritic eruptions of the skin in some of the areas as well as scattered papule lesions with or without central ulcerations. 900 Seventh Street, NW Suite 400 It is a gram positive, coccus shaped microbe, and contains catalase. 2014). Gram-positive organisms appear purple under the microscope as opposed to the other category of bacterial cell with its own unique cell wall, the Gram-negative rod or coccus, which stains red. A positive test leads to the development of blue or purple-blue on the disc within two minutes. The large polysaccharide molecule starch contains two parts, amylose and amylopectin, these are rapidly hydrolyzed using a hydrolase called alpha-amylase to produce smaller molecules: dextrins, maltose, and glucose. Figure 1. The sample was then sequenced using the Illumina MiSeq technology in UAFs DNA Core Lab. They are fairly small as well, usually about a millimeter in diameter and of a normal height. (2019, March 14). It is Gram positive, Coagulase positive, catalase and oxidase positive non-motile bacteria. I grew my isolated in Tryptic Soy Broth (TSB) for a week to prepare for DNA extraction. On this Wikipedia the language links are at the top of the page across from the article title. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Built with Enlightenment Theme and WordPress. Micrococcus luteus. 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. The oxygen class of the microbe, obligate aerobe, matches up with the predictions I had made about it because the bacteria was originally sourced in a nostril. Micrococcus luteus is generally harmless but can become an opportunistic pathogen in immunocompromised people or those with indwelling catheters. A very important test in the categorization of the staphylococci is the coagulase test. M. luteus has the capability to show dormancy without the formation of spores. U.S. 2022 American Association for Clinical Chemistry. Finally, when looking at the API 20E strip none of the results returned positive despite the culture being active and fresh from being streaked recently. The categorization of bacteria in the clinical laboratory is based on the reactivity of the organism when stained by the Grams staining reagents. Catalase test was the first biochemical test to be done . The coagulase test is performed by mixing a sample of organism with rabbit plasma. They grow in circular, entire, convex, and creamy yellow-pigmented colonies with diameters of approximately 4 mm after 2-3 days at 37C. It shows that it is mostly Actinobacteria, with some firmicules ,and proteobacteria mixed in (Figure 2). Oral microbial flora of reptiles includes bacteria from Proteus, Porphyromonas, Micrococcus, Salmonella and Staphylococcus genera 5,8,15. At U.S. Micro Solutions, our microbiology laboratory is a licensed, accredited source for thorough and accurate environmental testing . They can even survive in conditions that have very little of even no oxygen, using glycolysis and alternative electron acceptors to create ATP. Biochemical Tests in Microbiology Student Name Date 1 Lot Number(s) Record the lot numbers for each bacterial . Catalase is an enzyme produced by the organism to neutralize the toxic effects of hydrogen peroxide in the environment of the cell. The species Micrococcus luteus (Schroeter 1872) Cohn 1872 (Approved Lists 1980) emend. Colony pigmentation varies considerably but is usually different shades of yellow or cream-white. Unlike other actinobacteria, M. luteus expresses only one resuscitation-promoting factor that is required for the emergence from dormancy and has few other dormancy-related proteins. The catalase test tests to see if the microbe contains catalase. They are generally strict aerobes and can generally reduce nitrate. The streptococci and enterococci are categorized by expression of either beta, alpha, or gamma hemolysis on sBAP, depending on the genus/species. As mentioned, the type of hemolytic reaction produced on sBAP is a major clue toward the identification of the genus. Retrieved 06:20, April 16, 2019, from https://en.wikipedia.org/w/index.php?title=Micrococcus_luteus&oldid=887698104, Wikipedia contributors. Due to the thick structure of the bacterial cell wall, Gram-positive cocci retain the primary Grams stain, Crystal Violet. // PUGVIEW FETCH ERROR: 403 Forbidden National Center for Biotechnology Information 8600 Rockville Pike, Bethesda, MD, 20894 USA Contact Policies FOIA HHS Vulnerability Disclosure National Library of Medicine National Institutes of Health Table 1: Graph from Korona showing the percent reads of each organism, and to which taxonomic level. It may appear in irregular clusters, groups of four or eight. 2002). These include the slide or drop catalase test, the tube method, the semiquantitative catalase for the identification of Mycobacterium tuberculosis. This would be read A/NC. If acid is produced, the pH indicator will turn yellow. While every effort is made to ensure details distributed by Culture Collections are accurate, Culture Collections cannot be held responsible for any inaccuracies in the data supplied. Enterococcus faecalis. Micrococcus Luteus is a gram positive, non-motile, non-sporing cocci belonging to micrococcea family. Mannitol salt agar (MSA) is a selective, differential, and indicator medium used to isolate and identify Staphylococcus aureus from the clinical specimen. Staphylococcus spp. However, the most promising antibiotic regimen that is proposed for the treatment of the Micrococcus luteus seems to be a combination of amikacin, vancomycin, and rifampicin. The family, Micrococcaceae, has been shrinking. Micrococcus luteus is a constituent of the normal human buccal bacterial flora which forms yellowish colonies and appears as a gram-positive coccus typically arranged in tetrads. After it was sequenced using an Illumina MiSeq at the UAF Core lab, I used the online program Base Space to analyze the reads that I got from sequencing. Under the microscope they are round cells. About half of the Micrococcus luteus gram stain was found to carry plasmids of about one to 100MDa in size. Filter paper disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride (oxidase reagent) in dimethyl sulfoxide (DMSO) are used. Ans: Although it is a harmless saprophyte, Micrococcus luteus can act as an opportunistic pathogen. This test had VP, HIP, ESC, PYRA, aGAL, bGUR, bGAL, PAL, LAP, ADH, RIB, ARA, MAN, SOR, LAC, TRE, INU, RAF, AMD, and GLYG tests. 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. In the case of a negative test, no colour change is observed. When performing tests for physiological traits, the results were limited. Oxidase (modified oxidase) test: Positive. Biochemical Test and Identification of Staphylococcus aureus. Biochemical Pr Organism Enterococcus faecalis Lactococcus lactis Micrococcus luteus Staphylococcus The staphylococci are characterized by the formation of clusters of many cocci. The differentiation is based on the detection of oxidase enzyme. I used an oxidase test strip and water to determine if cytochrome C oxidase was present, and performed a catalase test to determine if catalase was present. Each genus lends itself to a separate tutorial. Biochemical Test Chart (You will not fill in every blank in this chart.) 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. The differentiation of the Gram-positive cocci encompasses 4 main exercises used to compare and contrast the characteristics of each family: These four tests will, as we shall see, allow for the differentiation of the families of organisms and will guide the laboratorian to other more definitive tests for the identification of the organism. Book a free counselling session. An interesting remaining family member, Microoccus antarcticus, was isolated from Antarctica, and is capable of growing at 4C. Habitat Micrococcus lives in a wide range of environments such as water, soil, and the dust whereas, Staphylococcus lives in the animal body. In a temporal study by Kloos and Musselwhite (1975), it was found that micrococci usually constituted from 1 to 20% of the total aerobic bacteria isolated from the skin of the head, legs, and arms, but less than 1% of those isolated from the high bacterial density areas of the nares and axillae. I also did a fluid thioglycolate test to determine the bacterias oxygen class. Micrococcus species are oxidase-positive, where these can be used to distinguish them from some other bacteria like most of the Staphylococcus species, which are generally oxidase-negative. The modified oxidase reagent is prepared as tetramethyl-p-phenylenediamine in certified grade dimethyl sulfoxide. The microdase test is a rapid method to differentiate Staphylococcus (-ve) from Micrococcus +ve) by detection of the enzyme oxidase. It has been associated with causing a variety of illnesses including septic arthritis, meningitis, endocarditis, chronic cutaneous infections in HIV-positive patients, and catheter infections. M. luteus is the majority of reads on the species level. The staphylococci and micrococci are catalase producers while the streptococci, enterococci, and a variety of other Gram-positive cocci are catalase-negative. They are usually normal flora but can be opportunistic pathogens in certain immunocompromised patients. Structure and PhysiologyThis bacteria is Gram-positive, spherical, and an obligate aerobe. Genus: Micrococcus. They also produce yellow or pink colonies when they are grown on the mannitol salt agar, micrococcus flavus, M. terreus, and M. yunnanensis. The categorization of the Gram-positive cocci based on their possession of the enzyme catalase, a quality which can be easily assayed in the lab. This simple-to-perform test categorizes the Gram-positive cocci as either catalase producers (+) or non-producers (-). 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). For example, M. luteus and M. lylae are 40-50% genetically different. As its name suggests, mannitol salt agar (MSA) contains 1% mannitol (sugar), 7.5% salt, and agar as a solidifying agent. The Culture Collections represent deposits of cultures from world-wide sources. Though today the immuno-compromised patients take the risk of the infection that has grown. They are fairly ubiquitous in the environment, and are small (0.5 to 3.5 micrometers in diameter) and non-motile. 2. 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. We will discuss this shortly. The mammalian skin that has M. luteus strain is also highly sensitive to the beta-lactam antibiotics. Microbiome 2(27). The positive catalase result lines up with M. luteus (Public Health England). Micrococcus luteus is another gram-positive coccus that also is catalase positive. Recent reports, however, confirm that micrococci may be associated with human infections, particularly in immunosuppressed patients. 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. Defining characteristics of Micrococcus are the ability to aerobically produce acid from glucose glycerol, aesculin hydrolysis, arginine dihydrolase, major pigment production, motility, and conversion of nitrate to nitrite. Micrococcus luteus, a commonly found member of the Micrococcaceae, produces round colonies which are convex (curving outward) with smooth, entire margins. Finally I used different antibiotic disks to check for its resistance to antibiotics, using Gentamicin, Cefoperazone, Vancomycin, Tobramycin, Amikacin, Trimethoprim, Oxacillin, and Cefazdin. This technique is centered on the performance of the classic Grams stain. For the micrococci, susceptibility to the antimicrobial agents, bacitracin and furazolidone, as well as the modified oxidase test can be performed to distinguish this group from the staphylococci. Reduction of O2 produces superoxide radicals and hydrogen peroxide, or the hydroxyl radical. Members of the Staphylcocci can be differentiated based on production of the enzyme coagulase. What are the Uses of Micrococcus Gram Stain? When looking at the genetic tests, most of the identified strains in the Korona test are Micrococcus luteus. This microbe forms large, round colonies. M. luteus has a G-C content of about 65-75 mol%. Micrococcus luteus are Gram-positive, to Gram-variable, motile -non motile, that are 0.5 to 3.5 micrometers in diameter and usually arranged in tetrads or irregular clusters. Micrococci can grow well in environments with little water or high salt concentrations, including sportswear that is made with synthetic fabrics. Continuing without changing cookie settings assumes you consent to our use of cookies on this device. The EMB plate is also selective for gram-negative bacteria which is probably why the bacteria didnt grow on it. The nasal cavity microbiome primarily consists of the phyla Actinobacteria, Firmicutes and Proteobacteria (Bassis et al. Alcaligenes faecalis Bacillus megaterium . Micrococcus luteus are Gram-positive cocci mostly arranged in tetrads and larger than Staphylococcus. This is in agreement with a study by Mohana et al., (2013) who reported that the carotenoid pigments had antioxidant properties of Micrococcus luteus was reported at IC50 of 4.5mg/ml, also the . The two unifying characteristics of these four families are their coccoid shape and the fact that they stain purple in the Grams method for visualizing bacteria microscopically. Annals of Allergy, Asthma and Immunology 122(1):17-24. Other Micrococcus isolates produce various useful products, such as long-chain aliphatic hydrocarbons for lubricating oils. Hybridization studies indicate that species within the genus Micrococcus are not closely related, showing as little as 50% sequence similarity. Reaction: To test for the presence of alpha amylase, a starch hydrolysis test can be performed. The kaiju metagenome binning shows that the microbe sample is not completely pure (Figure 2). These discrepancies could be due to human error, unpure culture, or an old agar plate. Organisms commonly found on the body include Micrococcus, Staphylococcus, and Corynebacterium species (Dermnet New Zeland). Source publication +9 Isolation and Identification of Potential Pathogenic Bacteria in Living Carp (Cyprinus carpio Linnaeus, 1758) Sold in. M. luteus tests positive for catalase, oxidase, utilization of D-glucose, sucrose and D-mannose, and has A2 type peptidoglycan that contains L-lysine as the diagnostic amino acid, MK-8 and MK-8 (H 2) are the major menaquinones (Stackebrandt et al. The oxidase test was negative, as the strip did not change color at all, where it would have turned purple if it was positive. Micrococcus luteus biochemical test result. I then repeated this three more times to further purify the isolate. This kit utilizes enzymatic reactions to release bacterial DNA from the cell. Micrococcus luteus is found in lots of places including skin, soil, dust, water, air, mouth, mucosae, oropharynx, and upper respiratory tract of humans (Wikipedia, Micrococcus luteus, 2019). Although the Micrococcus rarely causes infections or problems in the body, with the compromised immune systems, it has been known to get certain skin infections that are caused by Micrococcus luteus. The results of this analysis are shown in table 1. With the advent of newer molecular techniques, genus and species confirmation is even faster and easier. Take a clean, scratch free glass slide. This is a test for aerobic (able to use oxygen) catalase-positive bacteria such as Staphylococcus and Micrococcus. This is termed alpha () hemolysis and results in a greenish color surrounding the colony. Biochemical Tests in Microbiology answer sheet - Biochemical Tests in Microbiology Pre-Laboratory - Studocu Biochemical Tests in Microbiology lab answer sheet biochemical tests in microbiology questions why do some microbes specialize to use different food source than Skip to document Ask an Expert Sign inRegister Sign inRegister Home 1. These families of bacteria produce colonies which are variable both in size, consistency, and the type of hemolysis produced on sBAP. 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. Micrococcus is a genus of bacteria that is present in the Micrococcaceae family. This lines up with M. luteus resistances from the tests.
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