Complete lysis of the erythrocytes in the vicinity of the growing colony. They are fairly ubiquitous in the environment, and are small (0.5 to 3.5 micrometers in diameter) and non-motile. With this almost universal range of survivable living conditions that microbes can live in (particularly bacteria), it would be reasonable to assume that there would be at least one variety living in such a nice, wet, and aerated place as my shower drain. Biochemical Tests in Microbiology Student Name Date 1 Lot Number(s) Record the lot numbers for each bacterial . Krona chart of microbe shows bacterial classes thought to be present in the sample. They are fairly small as well, usually about a millimeter in diameter and of a normal height. 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. Subscribe to our e-mail newsletter to receive updates. 91 988-660-2456 (Mon-Sun: 9am - 11pm IST), Want to read offline? Like MSA, this medium also contains the pH indicator, phenol red. This simple-to-perform test categorizes the Gram-positive cocci as either catalase producers (+) or non-producers (-). The organism itself is susceptible to almost all drugs, with a few strains being resistant to nitrofurantoin, macrolides and lincomycin (Public Health Canada). I also grew it in a MacConkey (MAC) plate to see if it could ferment lactose and if it could grow with both crystal violet and bile salts to further confirm if it was gram negative or positive. This is likely either a cause of human error, unpure cultures, or not using agar plates that are fresh enough for the test. 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 shows that the sample contains bacteria from the Terrabacteria group. Wikipedia also says that Micrococcus luteus is an obligate aerobe, backing up what my results show (2019). Sarah D. Perkins., Government of Canada, Public Health Agency of Canada. Micrococci are usually not pathogenic. The mammalian skin that has M. luteus strain is also highly sensitive to the beta-lactam antibiotics. The fluid thioglycallate test showed that the bacteria was an obligate aerobe because the growth was concentrated at the top of the tube in the pink region. Principle of Microdase (Modified 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 enzyme. From four species that have been identify, only Bacillus subtilis and Pseudomonas diminuta that show ability to block pathogen bacteria Edwardsiella tarda. The modified oxidase reagent is prepared as tetramethyl-p-phenylenediamine in certified grade dimethyl sulfoxide. 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. 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. The categorization of bacteria in the clinical laboratory is based on the reactivity of the organism when stained by the Grams staining reagents. Micrococcaceae. For the detection of oxidase enzyme, filter paper circular disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride in dimethyl sulfoxide are used. The name of the genus is also called " Germanized " is written as Micrococcus. Micrococci can grow well in environments with little water or high salt concentrations, including sportswear that is made with synthetic fabrics. 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. This is a test for aerobic (able to use oxygen) catalase-positive bacteria such as Staphylococcus and Micrococcus. If an organism is capable of fermenting the sugar glucose, then acidic byproducts are formed and the pH indicator turns yellow. Micrococcus luteus growth on nutrient agar is bright mustard-yellow colonies as shown above image. I hypothesized that it would be a bacteria commonly found in the nasal cavities and likely from the aforementioned phyla, so it would likely do best living in an aerobic, humid, and warm environment. 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. Institute for Quality and Efficiency in Health Care. Micrococcus luteus is a coccus shaped gram-positive bacteria. 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. 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. We will discuss this shortly. 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 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 grow on simple media and their colonies are usually pigmented. 900 Seventh Street, NW Suite 400 2002 can be divided into three biovars that are distinguished by several chemotaxonomic and biochemical traits: biovar I represented by the type strain of Micrococcus luteus; biovar II represented by strain D7 DSM 14234 CCM 4959; and biovar III . The partial decomposition of the hemoglobin of the erythrocytes by a weaker hemolysin. They also produce yellow or pink colonies when they are grown on the mannitol salt agar, micrococcus flavus, M. terreus, and M. yunnanensis. Enter the email address you signed up with and we'll email you a reset link. Shape (Cocci/Diplococci/Rods) Cocci. 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. This lines up with M. luteus resistances from the tests. It is essential for differentiating catalase-positive Micrococcaceae from catalase-negative Streptococcaceae. The bacterium also colonizes the human mouth, mucosae, oropharynx and upper respiratory tract. The EMB agar showed no growth or change in color, also indicating the microbe was gram positive and a non-fermenter. At U.S. Micro Solutions, our microbiology laboratory is a licensed, accredited source for thorough and accurate environmental testing . The optimum growth temperature is 25-37C. I would hypothesise that because we clean our shower regularly, that most of the bacterium un the shower drain would come from people in my family taking a shower, and mostly be from the skin. The family, Micrococcaceae, has been shrinking. 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. Micrococcus luteus uses the amino acids and does not grow in the butt of the slant. Basics of Differentiation of Gram Positive Cocci, Author: Karen Krisher Retrieved 06:20, April 16, 2019, from https://en.wikipedia.org/w/index.php?title=Micrococcus_luteus&oldid=887698104, Wikipedia contributors. Gamma or no hemolysis results in no characteristic display in the vicinity of the colony. . Three bacteria, E.coli, Staphylococcus epidermis, and Micrococcus luteus, have been grown on TSI or Triple sugar iron agar medium, which is a . Source publication +9 Isolation and Identification of Potential Pathogenic Bacteria in Living Carp (Cyprinus carpio Linnaeus, 1758) Sold in. This is termed alpha () hemolysis and results in a greenish color surrounding the colony. Although the initial placement of the Gram- positive cocci into broad categories is relatively easy, further classification of some isolates can be challenging and requires a battery of tests to arrive at a definitive identification. I then transferred the pure culture into a TSB slant to preserve it, keeping it at around 3 degrees Celsius in the lab refrigerator. Many members of the genus have been reclassified into other genera. 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. 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. The oxygen class and the gram positiveness of the microbe also matches up with that of Micrococcus luteus. It is Gram-positive cocci in tetrads, catalase-positive, coagulase-negative, arranged in clusters that differ from Staphylococcus in attacking sugars oxidatively which may appear in irregular clusters, groups of four or eight. The API 20 Strep test I used came up with no conclusive results. 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]. I used the Kirby-Bauer, or disk diffusion test to test for this, described in lab handout 9. In Wikipedia, The Free Encyclopedia. The catalase test did return positive by bubbling, indicating that it does have the ability to break down the radical hydrogen peroxide into diatomic oxygen and hydrogen. Isolates of the M. luteus have been found to overproduce the riboflavin virus when they are grown on toxic organic pollutants like pyridine. (2) Micrococcus spp. This bacterium can withstand massive doses of UV radiation and it also has the capability to degrade certain pollutants such as petrol. This suggests that some of the Micrococcus species on the basis of ribosomal RNA analysis eventually can be re-classified into other microbial genera. [8], Norwegian researchers in 2013 found a M. luteus strain that synthesizes a pigment that absorbs wavelengths of light from 350 to 475 nanometers. They can even survive in conditions that have very little of even no oxygen, using glycolysis and alternative electron acceptors to create ATP. Examples of the colony morphology associated with each family is represented on this slide. 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. 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. I also did a fluid thioglycolate test to determine the bacterias oxygen class. It is a gram positive, coccus shaped microbe, and contains catalase. It is essential for differentiating catalase-positive Micrococcaceae from catalase-negative Streptococcaceae. CATALASE TEST: Catalases are enzymes that convert hydrogen peroxide (H2O2) into water and oxygen gas. Like all Staphylococci, S. saprophyticus is also clustering Gram-positive cocci, nonmotile, non-spore-forming, and . Further biochemical tests to identify include the catalase and oxidase test, and typical tests of a "colorful series . For example, M. luteus and M. lylae are 40-50% genetically different. The kaiju metagenome binning shows that the microbe sample is not completely pure (Figure 2). This is designated as beta ()-hemolysis. The Culture Collections represent deposits of cultures from world-wide sources. 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. Habitat Micrococcus lives in a wide range of environments such as water, soil, and the dust whereas, Staphylococcus lives in the animal body. In the 1920s, Alexander Fleming described lysozyme as a bactericidal factor of human and other animal tissues and secretions.1 He also discovered and named a yellow bacterium, Micrococcus lysodeikticus (now M luteus), that was highly susceptible to lysozyme-mediated killing.After exploring the susceptibility of other bacteria to lysozyme, Fleming proposed that M luteus and certain other . M. luteus is considered an opportunistic pathogen that can be responsible for some of the nosocomial infections. Some are based on monoclonal antibodies, and others on simple, rapid . 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. The Micrococcus strains isolated from various infections were most probably misclassified as staphylococci. Staphylococcus spp. Micrococcus luteusare Gram-positive cocci mostly arranged in tetrads and larger than Staphylococcus. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Built with Enlightenment Theme and WordPress. Micrococcus Public Health Agency of Canada., Public Health England. The MacConkey agar is selective for gram-negative which is why my microbe didnt show much growth on it, and because it didnt change colors it means it didnt ferment the lactose. Thank you for joining me, Karen Krisher, on this Pearl of Laboratory Medicine on Basics of Differentiation of Gram-positive Cocci.. The genera Staphylococcus, Micrococcus and Sarcina were recognized. 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. Intro: Microbes are everywhere, even in the most extreme environments and conditions. Micrococcus luteus was found gram-positive cocci, non-spore forming, non-haemolytic, non-motile aerobic or facultative anaerobes, arranged in pairs, irregular clusters and tetrads. // Make a tape label writing the color dot, your name, and the name of the media. // A positive test leads to the development of blue or purple-blue on the disc within two minutes. Micrococci have Gram-positive spherical cells ranging from about 0.5 to 3 micrometers in diameter and typically appear in tetrads. The tetrads of the micrococci, the grape like clusters of the staphylococci, and the pairs and/or chains of the streptococci are shown. 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. Micrococcus luteus is a Gram-positive to Gram-variable, nonmotile, tetrad-arranging, pigmented, saprotrophic coccus bacterium in the family Micrococcaceae. Intermediates or end products of these varied metabolic activities can be detected by performing biochemical assays on a bacterial culture. It is Gram positive, Coagulase positive, catalase and oxidase positive non-motile bacteria. Catalase, if present, will break down the hydrogen peroxide to water and oxygen. Micrococcus luteus This Gram positive coccus is found in tetrads, irregular clusters, and cubical packets of eight. Positive. The typical microscopic morphology of the Gram-positive cocci when using the Grams stain is represented in these three images. They grow in circular, entire, convex, and creamy yellow-pigmented colonies with diameters of approximately 4 mm after 2-3 days at 37C. 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 has survived for at least 34,000 to 170,000 years, as assessed by 16S rRNA analysis, and possibly much longer. They are positive for catalase and oxidase ( modified). 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. Only those with compromised immune systems are thought to be susceptible to an infection.DisinfectionM. Last updated: August 10, 2022 by Sagar Aryal. Annals of Allergy, Asthma and Immunology 122(1):17-24. They are positive for catalase and oxidase ( modified). Hybridization studies indicate that species within the genus Micrococcus are not closely related, showing as little as 50% sequence similarity. Bacteria Collection: Micrococcus luteus Additional Information. Cells are catalase positive, oxidase positive, and exhibit strictly aerobic metabolism. Micrococcus are aerobic, Gram-positive cocci ranging in size from 0.5 to 2.0 m in diameter. Figure 1. A number of sophisticated tools are now available for clinical diagnosis. Micrococci may be distinguished from staphylococci by a modified oxidase test as shown below-. Required fields are marked *. The bubbling reaction is almost immediate and distinct in appearance. Finally I used different antibiotic disks to check for its resistance to antibiotics, using Gentamicin, Cefoperazone, Vancomycin, Tobramycin, Amikacin, Trimethoprim, Oxacillin, and Cefazdin. Colonies typically have a lemon-yellow pigment. Similar to the situation in the prosthetic valve endocarditis that is caused by more aggressive and highly resistant bacteria. Micrococcus luteus biochemical test result. Though today the immuno-compromised patients take the risk of the infection that has grown. Micrococci have been isolated from the human skin, animal and dairy products, and in beer. Perkins1, Sarah D., Jennie Mayfield2, and Victoria Fraser3 And. Organisms commonly found on the body include Micrococcus, Staphylococcus, and Corynebacterium species (Dermnet New Zeland). U.S. 2022 American Association for Clinical Chemistry. When viewing the organism microscopically, the staining characteristics of the organism provide important information for identification. // Mannitol salt agar (MSA) is a selective, differential, and indicator medium used to isolate and identify Staphylococcus aureus from the clinical specimen. Pearls of Laboratory Medicine Your email address will not be published. // 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. Micrococcus luteus Grown on BrainHeart Infusion Agar, Klebsiella characteristics on MacConkey Agar, Clinical Case Leukocyte Vacoulation Bacterial Infection, Segmented neutrophilic granulocyte during degradation, DIC (Disseminated intravascular coagulation), Creatinine Phosphate Kinase (CPK) and CK-MB Overview. M. luteus is part of the normal flora of the human skin.Transmission and DiseaseM. An interesting remaining family member, Microoccus antarcticus, was isolated from Antarctica, and is capable of growing at 4C. Micrococcus luteus was one of the early examples of novel codon usage,[5][6] which led to the conclusion that the genetic code is not static, but evolves. 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%. Due to the thick structure of the bacterial cell wall, Gram-positive cocci retain the primary Grams stain, Crystal Violet. Reduction of O2 produces superoxide radicals and hydrogen peroxide, or the hydroxyl radical. This microbe forms large, round colonies. Staphylococcus spp. 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. 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. Ans: Although it is a harmless saprophyte, Micrococcus luteus can act as an opportunistic pathogen. They are found in soil, dust, water and air, and as part of the normal microbiota of skin. M. luteus present on the human skin can transform compounds present in sweat into compounds with an unpleasant odour. The third image represents the colony morphology of many of the streptococci and enterococci. When a drop of peroxide is placed on catalase-producing bacteria, bubbles appear when the oxygen gas is formed. 2. download full PDF here, Some of the species of Micrococcus, such as M. luteus which is yellow in colour, and M. roseus which is red. Micrococcus spp. Baird-Parker, A. c.: A classification of micrococci and staphylococci based on physiological and biochemical tests. What is the biochemical test for Micrococci roseus? Micrococcus luteus is generally harmless but can become an opportunistic pathogen in immunocompromised people or those with indwelling catheters. Maximum production of pigments was observed at 35C, pH 9 and at 4% (W/V) NaCl concentration. This would be read as K/A. It has also been isolated from foods such as milk and goats cheese. Filter paper disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride (oxidase reagent) in dimethyl sulfoxide (DMSO) are used. Micrococcus luteus is another gram-positive coccus that also is catalase positive. The modified oxidase reagent is prepared as tetramethyl-p-phenylenediamine in certified grade dimethyl sulfoxide. It is a gram positive, coccus shaped microbe, and contains catalase. My goal in this experiment was to isolate, characterize and identify a bacterial colony that arose from a sample taken from my roommates nose. M. luteus played an important part in Flemings discovery of Lysozyme which is the bodys natural antibiotic. Download Scientific Diagram from www.researchgate.net. Catalase test was the first biochemical test to be done . 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.