micrococcus luteus biochemical tests

Figure 2. Note the bright yellow, non-diffusable colony pigment which is a defining characteristic of M. luteus. 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. Micrococcus are aerobic, Gram-positive cocci ranging in size from 0.5 to 2.0 m in diameter. 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. Washington, DC 20001 Micrococcus luteus is a Gram-positive to Gram-variable, nonmotile, tetrad-arranging, pigmented, saprotrophic coccus bacterium in the family Micrococcaceae. 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. I grew my isolated in Tryptic Soy Broth (TSB) for a week to prepare for DNA extraction. 900 Seventh Street, NW Suite 400 Each genus lends itself to a separate 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. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Built with Enlightenment Theme and WordPress. Most of the species produce carotenoid pigments. Last updated: August 10, 2022 by Sagar Aryal. 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. These results might not be trustworthy. Micrococcus luteus has been shown to survive in oligotrophic environments for extended periods of time. If the agar plate is held up to a light source, you can sometimes see through the agar, as is pictured on the left. Simple biochemical tests like the one above have always been an important aid to identification of bacteria, because the different bacterial groups and species have characteristic metabolic activities. Luteus is an obligate aerobe (medical. Positive. Wikipedia contributors. Take a clean, scratch free glass slide. 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. CATALASE TEST: Catalases are enzymes that convert hydrogen peroxide (H2O2) into water and oxygen gas. Benecky M. J.; Frew J. E.; Scowen N; Jones P, Hoffman B. M (1993). . It has multiple antibiotic resistance genes including dihydropteroate synthase, glycerophosphoryl diester phosphodiesterase, and SSU ribosomal proteins. Micrococcus spp. luteus is capable of surviving in environments // This lines up with M. luteus resistances from the tests. The oxidase test was negative, as the strip did not change color at all, where it would have turned purple if it was positive. Those are extremely toxic because they are powerful oxidizing agents and destroy cellular constituents very rapidly. 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. To sample, I used sterile cotton swabs and streaked them on TSA plates. The oxidase test results suggest that the microbe does not contain oxidase, despite what the metagenome binning test showed. They grow in circular, entire, convex, and creamy yellow-pigmented colonies with diameters of approximately 4 mm after 2-3 days at 37C. This microbe is coccus shaped and forms in tetrads. Recent reports, however, confirm that micrococci may be associated with human infections, particularly in immunosuppressed patients. Micrococcus (pleural-micrococci) is free-living in the environment and also normal flora of the skin. I used the Kirby-Bauer, or disk diffusion test to test for this, described in lab handout 9. 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. Source publication +9 Isolation and Identification of Potential Pathogenic Bacteria in Living Carp (Cyprinus carpio Linnaeus, 1758) Sold in. 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. Micrococcus also not able to ferment glucose anaerobically (negative) Reply. 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. Your email address will not be published. Micrococcus luteus growth on nutrient agar is bright mustard-yellow colonies as shown above image. Micrococcus spp. Filter paper disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride (oxidase reagent) in dimethyl sulfoxide (DMSO) are used. Gamma or no hemolysis results in no characteristic display in the vicinity of the colony. 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. The mammalian skin that has M. luteus strain is also highly sensitive to the beta-lactam antibiotics. 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]. Micrococcus A study with 188 micrococci, identified only to the genus level, demonstrated MICs at achievable concentrations for most -lactams, aminoglycosides, glycopeptides, clindamycin and the most active drug in vitro, rifampin. AACC uses cookies to ensure the best website experience. 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. Source: Trainee Council in English, Hello, my name is Dr. Karen Krisher. 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. Optimum growth temperature is 25-37 C. M. luteus causes odours in humans when breaking down the components of sweat. 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. The partial decomposition of the hemoglobin of the erythrocytes by a weaker hemolysin. This is a test for aerobic (able to use oxygen) catalase-positive bacteria such as Staphylococcus and Micrococcus. Most of the bacterium in the gram stains were gram negative, but a significant amount, about twenty percent, showed up as gram positive. I used the PATRIC software to perform a metagenome binning and to assign a taxonomy to the bacteria. They also produce yellow or pink colonies when they are grown on the mannitol salt agar, micrococcus flavus, M. terreus, and M. yunnanensis. 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The GC content of the DNA ranges from about 65 to 75 mol%. After you have cultivated your organism on agar media, the next step is the microscopic examination. M. luteus can also cause septic shocks in immuno-compromised people. Like all Staphylococci, S. saprophyticus is also clustering Gram-positive cocci, nonmotile, non-spore-forming, and . 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. For the detection of oxidase enzyme, filter paper circular disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride in dimethyl sulfoxide are used. Required fields are marked *. The catalase test also indicated that the microbe does not have catalase, despite the metagenomic binning test suggesting it. Where the M. luteus can cause severe skin infections and is sometimes clinically mistaken for Staphylococcus aureus. We will discuss this shortly. Krona chart of microbe shows bacterial classes thought to be present in the sample. Micrococcus luteus is coagulase negative, bacitracin susceptible, and forms bright yellow colonies on nutrient agar. What are the Uses of Micrococcus Gram Stain? In conclusion, some of my results were inconclusive and conflicting. 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. They are found in many other places in the environment, including dust, water, and soil. For example, M. luteus and M. lylae are 40-50% genetically different. Of those only Vancomycin was closer than 50 millimeters, being 38 millimeters. 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. Isolates of the M. luteus have been found to overproduce the riboflavin virus when they are grown on toxic organic pollutants like pyridine. I chose to sample bacteria from inside my roommates nose. 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. They are fairly ubiquitous in the environment, and are small (0.5 to 3.5 micrometers in diameter) and non-motile. . The confidence on that reading is decently confident, evidenced by the blue coloring. In the final section of a study, it is essential to present important information, techniques, and variables. 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. // The configurations are the result of the plane of cellular division exhibited by the organism. Similar to the situation in the prosthetic valve endocarditis that is caused by more aggressive and highly resistant bacteria. They are generally strict aerobes and can generally reduce nitrate. This bacterium is often arranged in the form of circular tetrads and it forms bright yellow colonies on nutrient agar. They are indole negative, oxidase-positive, catalase-positive, and citrate negative. I used Prokka Genome Annotation to identify which genes are present in the bacterium, Kraken Metagenomics to identify what the DNA reads correlated to on different taxonomic levels, and SPAdes Genome Assembler to determine how many contigs were produced from the reads that were produced. 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. 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. Bharath. For the second control, 100 L of water sample dilutions were plated on agar-agar. The colony morphology is the same as well, being round, shiny, and sort of flat (Medical Laboratories). I then streaked the exposed swab onto a petri dish to allow the organisms to grow, incubating them at 25 degrees Celsius in a dark cabinet. Book a free counselling session. Micrococcus lylaeare Gram-positive cocci mostly arranged in tetrads. Micrococcus species, members of the family Micrococcaceae, are usually regarded as contaminants from skin and mucous membranes. In Wikipedia, The Free Encyclopedia. appear as agents of infection causing endocarditis. Many members of the genus have been reclassified into other genera. Micrococcus luteus is a coccus shaped gram-positive bacteria. Micrococcus luteus in tetrads arrangement. The microbiome of the nasal cavity can also change in response to environmental factors such as geographic location, and hygiene (Rawis et al. Microbes are too small to be seen by the naked eye; they can survive in conditions that many would think are unlivable like the anaerobic environment in the rumen of cows, hot springs, and cold Antarctic waters (What are microbes, 2010). Under the microscope they are round cells. This can occur due to the presence of a reduced number of proteins that can bind to penicillin. 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). If the infection leads to severe hemodynamic alterations, thus the valve replacement may become necessary. It is difficult to differentiate Kocuria from Micrococcus with conventional biochemical methods; therefore, these organisms are often reported together as Micrococcus/Kocuria species. Micrococci have Gram-positive spherical cells ranging from about 0.5 to 3 micrometers in diameter and typically appear in tetrads. Characteristics. Required fields are marked *. Some streptococci also possess unique cell wall carbohydrate antigens that can be identified by reactivity with specific indicator antibodies in an agglutination assay (Lancefield typing). Only the Micrococcus luteus species contained cytochrome c oxidase. A very important test in the categorization of the staphylococci is the coagulase test. They occur in pairs, tetrads or clusters but not in chains. From four species that have been identify, only Bacillus subtilis and Pseudomonas diminuta that show ability to block pathogen bacteria Edwardsiella tarda. Micrococcus species occur in a wide range of environments, including dust, water, and soil. [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]. 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. Micrococcus species by the Taxo A Bacitracin disk test can also be differentiated from staphylococcus species. 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. Download Scientific Diagram from www.researchgate.net. (2019, March 14). The mammalian skin that has M. luteus strain is also highly sensitive to the beta-lactam antibiotics. The sample was then sequenced using the Illumina MiSeq technology in UAFs DNA Core Lab. From: Infectious Diseases (Third Edition), 2010 View all Topics About this page The first control consisted of plates of agar-agar to test sterility. These organisms range in virulence potential from commensal organisms found on the skin and mucous membranes to pathogens associated with serious infections. // Some Micrococcus are pigmented bacteria; for example, M. luteus produces yellow colonies and M. roseus produces redish colonies. Staphylococcus spp. Micrococcus luteus. Gram Stain:Gram-positive cocci, arranged in clusters that differ from Staphylococcus. ? 2. Intro: Microbes are everywhere, even in the most extreme environments and conditions. M. luteus is an obligate aerobe (Medical Laboratories). [1] It is urease and catalase positive. They are found in many other places in the, M. luteus has one of the smallest genomes of all the bacteria. 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. Thank you for joining me, Karen Krisher, on this Pearl of Laboratory Medicine on Basics of Differentiation of Gram-positive Cocci.. Pearls of Laboratory Medicine Due to the thick structure of the bacterial cell wall, Gram-positive cocci retain the primary Grams stain, Crystal Violet. After observation of the colony and microscopic morphology, the production of catalase by the isolate is documented. Know more about our courses. They are catalase positive and often oxidase positive although this reaction may be weak (see Table 23.3 ). Discussion: When looking at all of the results for my isolate, they are not all consistent with Micrococcus luteus. It is often larger thanStaphylococcus. Several uncommon strains produce raised colonies with translucent, depressed centers. 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. They are catalase-positive and usually aerobic with strictly respiratory metabolism. Hybridization studies indicate that species within the genus Micrococcus are not closely related, showing as little as 50% sequence similarity. The staphylococci and micrococci are catalase producers while the streptococci, enterococci, and a variety of other Gram-positive cocci are catalase-negative. Staphylococcus spp. The streptococci and enterococci are categorized by expression of either beta, alpha, or gamma hemolysis on sBAP, depending on the genus/species. The differentiation is based on the detection of oxidase enzyme. The Micrococcus strains isolated from various infections were most probably misclassified as staphylococci. 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 often carry plasmids that provide the organism with useful traits. 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. 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. The results of these tests provide a biochemical profile, or "fingerprint," that can be used to classify or even identify the bacterial species. Staphylococci were distinguished by their ability to form acid from glucose anaerobically and sarcinas by the formation of cubical packets. They are positive for catalase and oxidase ( modified). A summary table is included which lists the results of the identification criteria discussed in the tutorial. 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. 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. I extracted the DNA using the PowerSoil DNA kit (manufactured by Qiagen) following manufacturer instructions. Rawis M, and AK Ellis (2019). Micrococcus luteus. Following incubation at 37oC, if the plasma forms a clot, the organism is coagulase positive. Some of the Micrococcus are pigmented bacteria, for example, M. roseus produces reddish colonies and M. luteus produces yellow colonies. There have been several deaths in immuno-compromised children that are caused by leukemia from the pulmonary hemorrhages because of Micrococcus. 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. See answer (1) best answer. 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. Its genome has a high G + C content. In Wikipedia, The Free Encyclopedia. They are considered as normal comensal of human skin and upper respiratory tract. Although it's tempting to write a summary of the entire study but it . This simple-to-perform test categorizes the Gram-positive cocci as either catalase producers (+) or non-producers (-). 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 family, Micrococcaceae, has been shrinking. 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. Micrococcus luteus is another gram-positive coccus that also is catalase positive. Whereas the M. variant has a G-C content of about 66-72mol%. // Coagulase Results: Hybridization studies show that there is no close genetic relationship between the species of Micrococcus bacteria. Micrococcus is the Gram-positive cocci that are about 0.5 to 3.5 micrometres in diameter and usually, these are arranged in tetrads or in irregular clusters. Subscribe to our e-mail newsletter to receive updates. 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. 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. Micrococci have been isolated from the human skin, animal and dairy products, and in beer. It has also been isolated from foods such as milk and goats cheese. Colonies typically have a lemon-yellow pigment. Beta-hemolysis is a defining characteristic of Staphylococcus aureus and a certain streptococci. Colony pigmentation varies considerably but is usually different shades of yellow or cream-white. 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 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. Because of their diversity, there are a variety of biochemical tests that are used by laboratories to identify the Gram-positive cocci. The nasal cavity microbiome primarily consists of the phyla Actinobacteria, Firmicutes and Proteobacteria (Bassis et al. It can be easily be mistaken for staphylococci, as they are very similar morphologically and physiologically (Wikipedia, Staphlyococcus Aureus). The bubbling reaction is almost immediate and distinct in appearance. Biochemical Pr Organism Enterococcus faecalis Lactococcus lactis Micrococcus luteus Staphylococcus 2002). 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 . Retrieved 06:20, April 16, 2019, from https://en.wikipedia.org/w/index.php?title=Micrococcus_luteus&oldid=887698104, Wikipedia contributors. The modified oxidase reagent is prepared as tetramethyl-p-phenylenediamine in certified grade dimethyl sulfoxide. Care must be taken when using a sample of organism acquired from a sBAP since erythrocytes also produce catalase. The organism itself is susceptible to almost all drugs, with a few strains being resistant to nitrofurantoin, macrolides and lincomycin (Public Health Canada). 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. To identify our isolate after obtaining the pure culture, we performed many different tests. Bacillus megaterium fermented sugars but didn't grow in the anaerobic area of the butt. The species Micrococcus luteus (Schroeter 1872) Cohn 1872 (Approved Lists 1980) emend. 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. 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. I also did a fluid thioglycolate test to determine the bacterias oxygen class. Date: FEB.11.2016 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.