I extracted the DNA using the PowerSoil DNA kit (manufactured by Qiagen) following manufacturer instructions. These results might not be trustworthy. They can even survive in conditions that have very little of even no oxygen, using glycolysis and alternative electron acceptors to create ATP. Filter paper disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride (oxidase reagent) in dimethyl sulfoxide (DMSO) are used. Colonies typically have a lemon-yellow pigment. Micrococci are usually not pathogenic. Reaction: To test for the presence of alpha amylase, a starch hydrolysis test can be performed. Staphylococcus aureus Staphylococcus spp. 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. 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. They have a respiratory metabolism, often producing little or no acid from carbohydrates, and are usually halotolerant, growing in 5% NaCl. 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. . You can change these settings at any time, but that may impair functionality on our websites. Gram Staining. Staphylococci are either producers of the enzyme coagulase or non-producers. Micrococcus luteus uses the amino acids and does not grow in the butt of the slant. After observation of the colony and microscopic morphology, the production of catalase by the isolate is documented. 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. Basics of Differentiation of Gram Positive Cocci, Author: Karen Krisher
Based on the place of origin of the bacterium that I isolated, I hypothesize that it will either be one of the above bacterium or a similar water loving organism, likely one that also forms a biofilm. I suspect that the API 20E test strip results were negated by having used an inactive colony, as the fluid thyoglycate test failed as well. Examples of the colony morphology associated with each family is represented on this slide. Obtain a glucose fermentation tube. The GC content of the DNA ranges from about 65 to 75 mol%. all 3 tests done w/SIM deeps just add Kovac's reagent for Indole test Alcaligenes faecalis (left) - . 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. 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. Typical colonies are often described as gray to white, moist or glistening. They are also catalase-positive and often weakly oxidase-positive ( modified oxidase test positive). If acid is produced, the pH indicator will turn yellow. 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. These families of bacteria produce colonies which are variable both in size, consistency, and the type of hemolysis produced on sBAP. CCTC (English)
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]. Micrococci are microbiologically characterized as gram-positive cocci, 0.5 to 3.5 m (micrometres; 1 m = 10-6 metre) in diameter. The colony morphology of being yellow, shiny and smooth line up perfectly with M. luteus (Public Health England). 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. (2019, March 14).
Each family of Gram-positive cocci has its own unique configuration. The micrococci produce tetrads consisting of 4 cocci clustered together. 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. Micrococcus (pleural-micrococci) is free-living in the environment and also normal flora of the skin. November 27, 2021 at 9:14 AM Hi sir, why Macrococcus and Micrococcus will not ferment . The genus Micrococcus consists of Gram-positive spheres occurring in tetrads and in irregular clusters that are usually non-motile and non-spore-forming. Included in the observation of the morphology of the colony is the effect that the bacterial growth has on the sheep erythrocytes in the agar medium. Washington, DC 20001 Bharath. This is designated as beta ()-hemolysis. 2019). 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. The taxonomic assignment of this microbe was micrococcus luteus because it was the only bin that PATRIC gave. 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. 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. They are found in many other places in the environment, including dust, water, and soil. I performed many tests to find out the colony morphology and physiology. M. luteus oxidize carbohydrates to form carbon dioxide and water, and it does not produce acid from the glucose as well as it does not make arginine dihydrolase or b-galactosidase. Each genus lends itself to a separate tutorial. From: Infectious Diseases (Third Edition), 2010 View all Topics About this page Is Micrococcus luteus indole positive? 1. 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. Where the M. luteus can cause severe skin infections and is sometimes clinically mistaken for Staphylococcus aureus. M. luteus has the capability to show dormancy without the formation of spores. These organisms range in virulence potential from commensal organisms found on the skin and mucous membranes to pathogens associated with serious infections. They are found in many other places in the, M. luteus has one of the smallest genomes of all the bacteria. It is an opportunistic pathogen, only pathogenic enough to cause disease in weakened immune systems (Medical Laboratories). 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. Catalase is an enzyme produced by the organism to neutralize the toxic effects of hydrogen peroxide in the environment of the cell. 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. 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. Once a presumptive identification has been made based on colony and microscopic morphology and the catalase reaction, additional tests can be performed to establish the genus and species of the organism. 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. Micrococcus also not able to ferment glucose anaerobically (negative) Reply. Further tests that I would do would be testing how much heat resistance it has, the density of a broth suspended sample using a dilution series, test for more antibiotic resistances, and how well it can grow in antibacterial mediums and mediums of different pH levels. 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). I kept the plate at room temperature for 7 days, and then selected a colony to purify using the pure culture streak plate method. 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. Most of these are mesophiles; some, like Micrococcus antarcticus which is found in Antarctica, are psychrophiles. 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 To sample, I used sterile cotton swabs and streaked them on TSA plates. Bacillus megaterium fermented sugars but didn't grow in the anaerobic area of the butt. AACC.org
Results of the biochemical tests demonstrated that the M. luteus and M. varians strains could be distinguished by their actions on glucose and nitrate reduction (Table I).
The kaiju metagenome binning shows that the microbe sample is not completely pure (Figure 2). They are positive for catalase and oxidase ( modified). Colony pigmentation varies considerably but is usually different shades of yellow or cream-white. Required fields are marked *. They are positive for catalase and oxidase ( modified). When using a fluid thyoglycollate test it resulted in the isolate being a strict aerobe, with all of the bacterium being at the top of the medium where it is oxygenic. Biochemical Pr Organism Enterococcus faecalis Lactococcus lactis Micrococcus luteus Staphylococcus Micrococcus luteus has been shown to survive in oligotrophic environments for extended periods of time. Some Micrococcus are pigmented bacteria; for example, M. luteus produces yellow colonies and M. roseus produces redish colonies. The nasal cavity microbiome primarily consists of the phyla Actinobacteria, Firmicutes and Proteobacteria (Bassis et al. (negative). Retrieved 06:20, April 16, 2019, from https://en.wikipedia.org/w/index.php?title=Micrococcus_luteus&oldid=887698104, Wikipedia contributors. Only the Micrococcus luteus species contained cytochrome c oxidase. The partial decomposition of the hemoglobin of the erythrocytes by a weaker hemolysin. 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. The reactions of the four isolates indicated that they belonged to the species M. Zuteus (Kocur & Martinec, 1972). . 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. The tetrads of the micrococci, the grape like clusters of the staphylococci, and the pairs and/or chains of the streptococci are shown. Ans: Although it is a harmless saprophyte, Micrococcus luteus can act as an opportunistic pathogen. It has also been isolated from foods such as milk and goats cheese. 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. It grew in circular, entire, convex and creamy yellow pigmented colonies heaving 0.5-2.5 diameter.
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. Micrococcus has a substantial cell wall in which it may comprise as much as 50% of the cell mass. 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. Although of low virulence, the germs may become more pathogenic in patients with impaired resistance, colonizing the surface of heart valves. Your email address will not be published. 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. Your email address will not be published. A positive test leads to the development of blue or purple-blue on the disc within two minutes. It can be easily be mistaken for staphylococci, as they are very similar morphologically and physiologically (Wikipedia, Staphlyococcus Aureus). 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. The metabolic pathways required for biomass production in silico were determined based on earlier models of actinobacteria. Those are extremely toxic because they are powerful oxidizing agents and destroy cellular constituents very rapidly. Your email address will not be published. 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. Most of the bacterium in the gram stains were gram negative, but a significant amount, about twenty percent, showed up as gram positive. 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. CATALASE TEST: Catalases are enzymes that convert hydrogen peroxide (H2O2) into water and oxygen gas. Source: Trainee Council in English, Hello, my name is Dr. Karen Krisher. The confidence on that reading is decently confident, evidenced by the blue coloring. SUMMARY: 1250 Gram-positive and catalase-positive cocci were isolated from bacon, pig and human skin and dust, and their morphology, physiology and biochemical characters examined.
Enterococcus spp. Gamma or no hemolysis results in no characteristic display in the vicinity of the colony. It has been isolated from human skin. This suggests that some of the Micrococcus species on the basis of ribosomal RNA analysis eventually can be re-classified into other microbial genera. Beta-hemolysis is a defining characteristic of Staphylococcus aureus and a certain streptococci. The Culture Collections represent deposits of cultures from world-wide sources. 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 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. 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. Micrococcus., h. Shahidi Bonjar. It is an aerobic exopolysaccharide producing bacteria that may be found on the skin, mouth and sometimes in the throat of mammals 13,14. Under the microscope they are round cells. I also did a fluid thioglycolate test to determine the bacterias oxygen class. M. luteus causes odours in humans when breaking down the components of sweat. Luteus is an obligate aerobe (medical. This is termed alpha () hemolysis and results in a greenish color surrounding the colony. The streptococci and enterococci are categorized by expression of either beta, alpha, or gamma hemolysis on sBAP, depending on the genus/species. Ans: Micrococci, like many other representatives of the Actinobacteria, can be catabolically versatile, with the ability to utilize a wide range of unusual substrates, such as herbicides, pyridine, chlorinated biphenyls, and oil. 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. If the infection leads to severe hemodynamic alterations, thus the valve replacement may become necessary. It has survived for at least 34,000 to 170,000 years, as assessed by 16S rRNA analysis, and possibly much longer. 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. Oxidase (modified oxidase) test: Positive. Know more about our courses. The microbiome of the nose. 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. 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). Bassis CM, AL Tang, VB Young, and MA Pynnonen (2014). 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. Table 1: Graph from Korona showing the percent reads of each organism, and to which taxonomic level. The colony forms as a yellow, shiny round blob. 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. Micrococcus Public Health Agency of Canada., Public Health England. This simple-to-perform test categorizes the Gram-positive cocci as either catalase producers (+) or non-producers (-). This kit utilizes enzymatic reactions to release bacterial DNA from the cell. 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. Micrococcus spp. The oxidase test was negative, as the strip did not change color at all, where it would have turned purple if it was positive. 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. Catalase test was the first biochemical test to be done . The modified oxidase reagent is prepared as tetramethyl-p-phenylenediamine in certified grade dimethyl sulfoxide. M. luteus is considered an opportunistic pathogen that can be responsible for some of the nosocomial infections. This lines up with M. luteus resistances from the tests. Wikipedia contributors. [7], In 2003, it was proposed that one strain of Micrococcus luteus, ATCC 9341, be reclassified as Kocuria rhizophila. 900 Seventh Street, NW Suite 400 For the second control, 100 L of water sample dilutions were plated on agar-agar. Download Scientific Diagram from www.researchgate.net.
Whereas the M. variant has a G-C content of about 66-72mol%.
Similar to the situation in the prosthetic valve endocarditis that is caused by more aggressive and highly resistant bacteria. The sequencing of Micrococcus luteus was supported because of its major potential role in the case of bioremediation and its importance in the field of biotechnology. I performed a Gram stain test to identify if the bacterium was gram negative or positive, as described in the Lab 4 handout. Further biochemical tests to identify include the catalase and oxidase test, and typical tests of a "colorful series . This would be read A/NC. The genome of the Micrococcus is rich in guanine and cytosine, they typically exhibit about 65 to 75% GC-content. nishinomiyaensis and Micrococcus luteus. luteus is capable of surviving in environments Cells are catalase positive, oxidase positive, and exhibit strictly aerobic metabolism. 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). Enterobacter aerogenes fermented the sugars but turned to the amino acids. The oxidase test tests to see if the microbe contains cytochrome c oxidase. In future works with this microbe, I probably would want to purify the culture more and redo the tests. 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. Characteristics. In Wikipedia, The Free Encyclopedia. Micrococcus lylaeare Gram-positive cocci mostly arranged in tetrads. Bacteria Detail., The Editors of Encyclopdia Britannica. The categorization of bacteria in the clinical laboratory is based on the reactivity of the organism when stained by the Grams staining reagents. The colony took 16 days to be purified. Catalase, if present, will break down the hydrogen peroxide to water and oxygen. My goal in this experiment was to isolate, characterize and identify a bacterial colony that arose from a sample taken from my roommates nose. Discussion: When looking at all of the results for my isolate, they are not all consistent with Micrococcus luteus. Make a tape label writing the color dot, your name, and the name of the media. Micrococcus, genus of spherical bacteria in the family Micrococcaceae that is widely disseminated in nature. The conflicting results of the metagenome binning and the catalase test influenced this mistake. Institute for Quality and Efficiency in Health Care. Staphylococcus spp. Micrococcus luteusare Gram-positive cocci mostly arranged in tetrads and larger than Staphylococcus. I think based on all this information, that my microbe is in fact micrococcus luteus as suggested by the PATRIC metagenome binning test, and the krona (Figure 1). . Micrococcus spp. 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. They grow on simple media and their colonies are usually pigmented.