Abstract Micrococcus luteus IFO 3333 cells, both treated with chemical reagents and non-treated, were observed with a scanning electron microscope (SEM). Members of the Staphylcocci can be differentiated based on production of the enzyme coagulase. Take a clean, scratch free glass slide. As the microbe is gram positive this means that it has a large peptidoglycan layer and lacks a lipopolysaccharide layer. 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. 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. This is a test commonly used when trying to identify Gram-negative enteric bacteria, all of which are glucose fermenters but only some of which produce gas. Micrococci have Gram-positive spherical cells ranging from about 0.5 to 3 micrometers in diameter and typically appear in tetrads. Then to actually isolate a bacterium, I chose a colony from the initial plate and did a quadrant streak of it to further isolate the bacterium, and then incubated it at 38 degrees Celsius for a week. Micrococcus luteus characteristics possess unusual abilities to tolerate and to use very toxic organic molecules as carbon sources and it combines these activities with tolerance to metals. They are generally strict aerobes and can generally reduce nitrate. There have been several deaths in immuno-compromised children that are caused by leukemia from the pulmonary hemorrhages because of Micrococcus. Thank you for joining me, Karen Krisher, on this Pearl of Laboratory Medicine on Basics of Differentiation of Gram-positive Cocci.. These can indicate that the genus of the Micrococcus is more closely related to the genus Arthrobacter than it is to other coccoid genera such as Staphylococcus and Planococcus. 1. They can be found in boiling hot springs; they can be found in frigid waters in the artic. They grow on simple media and their colonies are usually pigmented. We were aiming to isolate a bacterium from this initial environmental sample by using repeated quadrant streaks to isolate single species colonies, therefore producing a pure culture that we could do a multitude of tests on which include Gram staining, genetic analysis and antibiotic testing along with many other tests. // appear as agents of infection causing endocarditis. It has been isolated from human skin. Coagulase Results: The identified reads only made up a total of twenty seven percent of the total reads, but the majority of those reads were for M. luteus. 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. Like all Staphylococci, S. saprophyticus is also clustering Gram-positive cocci, nonmotile, non-spore-forming, and . I performed a Gram stain test to identify if the bacterium was gram negative or positive, as described in the Lab 4 handout. . They are fairly ubiquitous in the environment, and are small (0.5 to 3.5 micrometers in diameter) and non-motile. Following incubation at 37oC, if the plasma forms a clot, the organism is coagulase positive. An obligate aerobe, M. luteus is found in soil, dust, water and air, and as part of the normal microbiota of the mammalian skin. 2023 Universe84a.com | All Rights Reserved, Blog: Microbiology and infectious disease, Anti-Mullerian Hormone (AMH) Test: Introduction, Result, Unit, Normal Range, Test Method, Clinical Significance, and Keynotes, Anti -TPO Antibody: Introduction, Test Result, Unit, Normal Range, Assaying Method, and Keynotes, HPV Genes detection using Real-Time PCR: Introduction, Principle, Test Requirements, Procedure, Result Interpretation and Keynotes, Microbiology Reporting Techniques: Introduction, List of Templates, and Keynotes, Acetamide Utilization Test: Introduction, Composition, Principle, Test Requirements, Procedure, Result-Interpretation, Limitations, and Keynotes, https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/887570/UK_SMI_ID_07i4.pdf, https://en.wikipedia.org/wiki/Micrococcus_luteus, https://europepmc.org/article/med/14576986, https://www.ajicjournal.org/article/S0196-6553(13)01146-2/fulltext. Micrococcus luteus, a commonly found member of the Micrococcaceae, produces round colonies which are convex (curving outward) with smooth, entire margins. About half of the Micrococcus luteus gram stain was found to carry plasmids of about one to 100MDa in size. Know more about our courses. There are around nine species that are recognized in the genus. This microbe forms large, round colonies. 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. Growth or weak growth is observed at 45C, at pH 10, and in the presence of 10% sodium chloride (NaCl). Micrococcus luteus are Gram-positive cocci mostly arranged in tetrads and larger than Staphylococcus. Staphylococcus aureus Staphylococcus spp. (2) Micrococcus spp. The sample was then sequenced using the Illumina MiSeq technology in UAFs DNA Core Lab. Only the Micrococcus luteus species contained cytochrome c oxidase. For example, Micrococcus varians is now known as Kocuria varians. Retrieved 06:20, April 16, 2019, from https://en.wikipedia.org/w/index.php?title=Micrococcus_luteus&oldid=887698104, Wikipedia contributors. It shows that the sample contains bacteria from the Terrabacteria group. Whereas the M. variant has a G-C content of about 66-72mol%. It is a gram positive, coccus shaped microbe, and contains catalase. It has been isolated from human skin. They are catalase positive and often oxidase positive although this reaction may be weak (see Table 23.3 ). A positive test leads to the development of blue or purple-blue on the disc within two minutes. This is a test for aerobic (able to use oxygen) catalase-positive bacteria such as Staphylococcus and Micrococcus. They are found in many other places in the environment, including dust, water, and soil. 2-9 In these reports micrococci were identified on the basis of their . Micrococcus luteus biochemical test result. The species Micrococcus luteus (Schroeter 1872) Cohn 1872 (Approved Lists 1980) emend. Most of the bacterium in the gram stains were gram negative, but a significant amount, about twenty percent, showed up as gram positive. In conclusion, some of my results were inconclusive and conflicting. They are found in soil, dust, water and air, and as part of the normal microbiota of skin. Although of low virulence, the germs may become more pathogenic in patients with impaired resistance, colonizing the surface of heart valves. Microbiome 2(27). Micrococci may be distinguished from staphylococci by a modified oxidase test as shown below-. The agglutinability of the cells with antiserum containing anti-teichuronic acid antibody was examined. Table 2: Graph of the genomic reads by taxonomic level using Korona. Filter paper disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride (oxidase reagent) in dimethyl sulfoxide (DMSO) are used. It is an aerobic exopolysaccharide producing bacteria that may be found on the skin, mouth and sometimes in the throat of mammals 13,14. Hybridization studies indicate that species within the genus Micrococcus are not closely related, showing as little as 50% sequence similarity. Isolates of the M. luteus have been found to overproduce the riboflavin, Micrococcus Luteus Gram Stain Characteristics, Micrococci have been isolated from the human skin, animal and dairy products, and in beer. The GC content of the DNA ranges from about 65 to 75 mol%. Each genus lends itself to a separate tutorial. Micrococcus lylaeare Gram-positive cocci mostly arranged in tetrads. These organisms range in virulence potential from commensal organisms found on the skin and mucous membranes to pathogens associated with serious infections. They grow in circular, entire, convex, and creamy yellow-pigmented colonies with diameters of approximately 4 mm after 2-3 days at 37C. I am an associate professor in the Clinical Laboratory Science program at Wayne State University. Although many of the members of these families have low pathogenicity and are classified as causes of opportunistic infections, those organisms most often cited as pathogens are listed on this slide. The API 20 Strep test I used came up with no conclusive results. Maximum production of pigments was observed at 35C, pH 9 and at 4% (W/V) NaCl concentration. Micrococcus lutues are Gram positive cocci that are 0.5 to 3.5 m in diameter and arranged in tetrads or irregular clusters. 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. Recently, as an opportunistic pathogen, this organism was recognized and it has been implicated in recurrent bacteremia, septic arthritis, septic shock, endocarditis, intracranial suppuration, meningitis, and cavitating pneumonia in immunosuppressed patients. They are seldom motile and are non-sporing. 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. The Kocuria rhizophila strain ATCC 9341 has been used in quality control for sterility testing, as a test for the effectiveness of antibiotics and fungicides, and for doxycycline, tetracycline, and chloramphenicol susceptibility testing since 1966 under the designation Micrococcus luteus [4]. Under the microscope they are round cells. 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. Staphylococcus spp. The MacConkey agar showed very little growth, and did not have a change in color, indicating that the microbe was gram positive and not a fermenter. This bacterium is often arranged in the form of circular tetrads and it forms bright yellow colonies on nutrient agar. Is Micrococcus luteus indole positive? J Gen Microbiol 30(1963)409-427 . 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. Micrococcus as the cause of infections is easy to overlook because the infections that are caused by this bacterium are rare as well as the bacterium is a natural part of the skin's bacterial flora. Staphylococcus saprophyticus is a Gram-positive, coagulase-negative coccus that is an important part of the group of microorganisms causing urinary tract infections (UTIs), particularly in young sexually active females. Micrococcus luteus (left) Alcaligenes faecalis (middle) Reduction of nitrate to nitrite to be used as a final electron acceptor/Nitrate reductase. M. luteus has the capability to show dormancy without the formation of spores. Sarah D. Perkins., Government of Canada, Public Health Agency of Canada. Welcome to this Pearl of Laboratory Medicine on Basics of Differentiation of Gram-positive Cocci.. The microbiome of the nasal cavity can also change in response to environmental factors such as geographic location, and hygiene (Rawis et al. On top of that, most of the bacterium that were stained were gram negative, which conflicts with this result. Micrococcus luteus biochemical test result. Bacteria Collection: Micrococcus luteus Additional Information. A very important test in the categorization of the staphylococci is the coagulase test. 2019). About half of the Micrococcus luteus gram stain was found to carry plasmids of about one to 100MDa in size. It is essential for differentiating catalase-positive Micrococcaceae from catalase-negative Streptococcaceae. M. luteus causes odours in humans when breaking down the components of sweat. 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. Catalase test was the first biochemical test to be done . Ans: Although it is a harmless saprophyte, Micrococcus luteus can act as an opportunistic pathogen. I isolated the DNA by lysing the cell and using the Power Sol DNA Isolation Kit to isolate the DNA from the other parts of the cell. Required fields are marked *. 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. Its genome has a high G + C content. Many of the tests did line up with M. luteus though, such as the fluid thyoglycate test, which showed that it was an obligate aerobe. Micrococcus species are strictly aerobic Gram-positive cocci arranged in tetrads or irregular clusters, and cells range from 0.5 to 3 m in diameter. It did not reduce sulphur, digest gelatin, or reduce nitrate, among some of the more interesting tests, which all disagree with M. luteus. Micrococcus also not able to ferment glucose anaerobically (negative) Reply. When looking back after culturing the isolate, these hypothesies were supported by several of the tests, and served as a good tool to steer me towards what the isolate may be. Examples of the colony morphology associated with each family is represented on this slide. Recent reports, however, confirm that micrococci may be associated with human infections, particularly in immunosuppressed patients. Mannitol salt agar (MSA) is a selective, differential, and indicator medium used to isolate and identify Staphylococcus aureus from the clinical specimen. If acid is produced, the pH indicator will turn yellow. Positive. Micrococcus luteus is coagulase negative, bacitracin susceptible, and forms bright yellow colonies on nutrient agar. Though not a spore former, the Micrococcus cells can survive for an extended period of time, both at refrigeration temperatures and in nutrient-poor conditions such as sealed in amber. In future works with this microbe, I probably would want to purify the culture more and redo the tests. We will discuss this shortly. 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. What is the biochemical test for Micrococci roseus? What are the Diseases that are Caused By Micrococcus? This is termed alpha () hemolysis and results in a greenish color surrounding the colony. This would be read K/NC. The Bacterial Genomic DNA Isolation Kit provides convenient and simple step-by-step method for isolating quality genomic DNA from gram-negative and gram-positive bacterial species. . M. luteus present on the human skin can transform compounds present in sweat into compounds with an unpleasant odour. 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. Some of the species of Micrococcus, such as M. luteus which is yellow in colour, and M. roseus which is red. Thus, when dealing with Micrococcus infections, it usually takes several cultures that are being grown and examined before one realizes that Micrococcus is indeed the culprit. Streptococcus spp. Micrococcus spp. 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. AACC.org In Wikipedia, The Free Encyclopedia. When viewing the organism microscopically, the staining characteristics of the organism provide important information for identification. U.S. 2022 American Association for Clinical Chemistry. I performed many tests to find out the colony morphology and physiology. It is reported here that gliotoxin selectively spares a unique class of haemopoietic stem cell that forms large (HPP) colonies in the presence of mixtures of MCSF and IL3. Micrococcus luteus. Coagulase, which is an enzyme involved in the conversion of serum fibrinogen to fibrin, causes the clotting of plasma. It has survived for at least 34,000 to 170,000 years, as assessed by 16S rRNA analysis, and possibly much longer. Gamma or no hemolysis results in no characteristic display in the vicinity of the colony. I extracted the DNA using the PowerSoil DNA kit (manufactured by Qiagen) following manufacturer instructions. https://en.wikipedia.org/w/index.php?title=Micrococcus_luteus&oldid=887698104, https://en.wikipedia.org/w/index.php?title=Staphylococcus_aureus&oldid=890960280, An exploration into a pharmacists microbes, An exploration of microbes present in the blood of processed moose. The positive catalase result lines up with M. luteus (Public Health England). Biochemical Test Chart (You will not fill in every blank in this chart.) In contrast to staphylococci, usually, penicillin is sensitive. Characteristics. // Further biochemical tests to identify include the catalase and oxidase test, and typical tests of a "colorful series . Staphylococci are either producers of the enzyme coagulase or non-producers. I also hypothesize that it will be an aerobic organism, given that I found it in a well aerated environment and it has survived until I cultured it. The bacterium also colonizes the mouth, mucosae, oropharynx, and upper respiratory tract. We found this to be true because the filter paper turned blue, which showed that the species has the cytochrome c oxidase enzyme. Micrococcus luteusare Gram-positive cocci mostly arranged in tetrads and larger than Staphylococcus. 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. Kaiju webserver metagenome binning analysis chart. luteus is capable of surviving in environments It has also been isolated from foods such as milk and goats cheese. The colony forms as a yellow, shiny round blob. Micrococcus species occur in a wide range of environments, including dust, water, and soil. The partial decomposition of the hemoglobin of the erythrocytes by a weaker hemolysin. They have a respiratory metabolism, often producing little or no acid from carbohydrates, and are usually halotolerant, growing in 5% NaCl. 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. The differentiation is based on the detection of oxidase enzyme. Catalase, if present, will break down the hydrogen peroxide to water and oxygen. Biochemical Test and Identification of Staphylococcus aureus. 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. I also had to do the thyoglycate test 3 times to get a conclusive result, further making me skeptical of how active the culture was during the physical tests during week 6, which is where almost all of the inconsistencies arose. Your email address will not be published. The Micrococcus strains isolated from various infections were most probably misclassified as staphylococci. Micrococcus luteus growth on nutrient agar is bright mustard-yellow colonies as shown above image. 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. The colony took 16 days to be purified. 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. Discussion: When looking at all of the results for my isolate, they are not all consistent with Micrococcus luteus. [3] Its genome was sequenced in 2010 and is one of the smallest genomes of free-living Actinomycetota sequenced to date, comprising a single circular chromosome of 2,501,097 bp.[4]. Cultures:- Nutrient broth cultures of Micrococcus luteus and Proteus vulgaris (young cultures) Procedure: Wet Mount Preparation . 2- M. luteus 3- M.roseus Culture: - Strictly aerobic at 37C incubation (24 hr) - Grow on ordinary media Nutrient agar - Blood agar and on the Blood agar M. roseus (pink) M. luteus (white) M.varians (yellow) - On m annitol salt agar grow given r ise to rose or pink colonies except M. roseus. A summary table is included which lists the results of the identification criteria discussed in the tutorial. Results: Regarding the gram stain test, my isolate was gram variable, I ensured that the strain was fresh so that the age of the culture was the same throughout the test. Once the culture was deemed pure enough, I inoculated a slant tube. In the case of a negative test, no colour change is observed. The differentiation is based on the detection of the oxidase enzymes. To identify our isolate after obtaining the pure culture, we performed many different tests. The modified oxidase reagent is prepared as tetramethyl-p-phenylenediamine in certified grade dimethyl sulfoxide. M. lylae can be distinguished from the closely related species Micrococcus luteus by lysozyme susceptibility, genetic composition, and the type of cell-wall peptidoglycan. The configurations are the result of the plane of cellular division exhibited by the organism. View Online Copy of Unknown ID Chart.xlsx from BIOL 250L at University of South Carolina. The Gram stain, while it was gram variable, does not ideally match with the genetic test that resulted in Micrococcus luteus, which can be gram variable but is usually gram positive (Bonjar). I chose to sample bacteria from inside my roommates nose. Alpha-hemolytic colonies often assume a greenish hue. Washington, DC 20001 The nasal cavity microbiome primarily consists of the phyla Actinobacteria, Firmicutes and Proteobacteria (Bassis et al. Gram Stain:Gram-positive cocci, arranged in clusters that differ from Staphylococcus. Streptococci and enterococci are observed to produce pairs and chains of cocci of varying length. They are fairly ubiquitous in the environment, and are small (0.5 to 3.5 micrometers in diameter) and non-motile. [8], Norwegian researchers in 2013 found a M. luteus strain that synthesizes a pigment that absorbs wavelengths of light from 350 to 475 nanometers. 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 negative oxidase result conflicts with M. luteus (Public Health England). Wieser et al. These include the slide or drop catalase test, the tube method, the semiquantitative catalase for the identification of Mycobacterium tuberculosis. Micrococcus luteus is a Gram-positive to Gram-variable, nonmotile, tetrad-arranging, pigmented, saprotrophic coccus bacterium in the family Micrococcaceae. 91 988-660-2456 (Mon-Sun: 9am - 11pm IST), Want to read offline? Micrococcus Catalase Test: The catalase test facilitates the detection of the enzyme catalase in bacteria. From four species that have been identify, only Bacillus subtilis and Pseudomonas diminuta that show ability to block pathogen bacteria Edwardsiella tarda. M. luteus has one of the smallest genomes of actinobacteria with a circular chromosome of 2,501,097 base pairs and a GC content of 73%. // The Culture Collections represent deposits of cultures from world-wide sources. Structure and PhysiologyThis bacteria is Gram-positive, spherical, and an obligate aerobe. Continuing without changing cookie settings assumes you consent to our use of cookies on this device. While defining the characteristics of the Micrococcus are the ability to produce acid aerobically from the aesculin hydrolysis, glucose glycerol, arginine dihydrolase, motility, major pigment production, and conversion of nitrate to nitrite. I grew my bacteria on an Eosin Methylene Blue (EMB) plate to see if it could ferment lactose and if it could grow with methylene blue which selects for gram negative bacteria. The colony morphology of being yellow, shiny and smooth line up perfectly with M. luteus (Public Health England). 570 . Micrococcus are aerobic, Gram-positive cocci ranging in size from 0.5 to 2.0 m in diameter. The M. luteus genome encodes about four sigma factors and fourteen response regulators, a finding indicative of the adaptation to a rather strict ecological niche. Reaction: To test for the presence of alpha amylase, a starch hydrolysis test can be performed. The tests that did not agree were most likely from not having an active colony used in the experiment, such as the oxidase test being negative or the API 20 E test strip showing that the isolate did not reduce nitrate, which it does, referencing Medical Laboratories. The oxidase test results suggest that the microbe does not contain oxidase, despite what the metagenome binning test showed.
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