2. Notice that beta-hemolysis results in a total lysis or clearing of the agar in the area of colony growth. appear as agents of infection causing endocarditis. Required fields are marked *. 570 . M. luteus causes odours in humans when breaking down the components of sweat. Micrococcus luteus in tetrads arrangement. Further biochemical tests to identify include the catalase and oxidase test, and typical tests of a "colorful series . The tetrads of the micrococci, the grape like clusters of the staphylococci, and the pairs and/or chains of the streptococci are shown. 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. Micrococcus are aerobic, Gram-positive cocci ranging in size from 0.5 to 2.0 m in diameter. This would be read K/NC. Obtain a glucose fermentation tube. Biochemical Tests in Microbiology Student Name Date 1 Lot Number(s) Record the lot numbers for each bacterial . With the advent of newer molecular techniques, genus and species confirmation is even faster and easier. // 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. Pearls of Laboratory Medicine Gamma or no hemolysis results in no characteristic display in the vicinity of the colony. Coagulase production is used as a virulence factor by the organism. (2010) What are microbes? Micrococcus also not able to ferment glucose anaerobically (negative) Reply. Culture Characteristics: Colonies are shades of yellow or red. This lines up with M. luteus resistances from the tests. So far there are two genome sequences that have been done. It shows that the sample contains bacteria from the Terrabacteria group. [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 are positive for catalase and oxidase ( modified). If acid is produced, the pH indicator will turn yellow. This microbe forms large, round colonies. It can be easily be mistaken for staphylococci, as they are very similar morphologically and physiologically (Wikipedia, Staphlyococcus Aureus). The family, Micrococcaceae, has been shrinking. On top of that, most of the bacterium that were stained were gram negative, which conflicts with this result. This microbe forms large, round colonies. The reactions of the four isolates indicated that they belonged to the species M. Zuteus (Kocur & Martinec, 1972). The mammalian skin that has M. luteus strain is also highly sensitive to the beta-lactam antibiotics. I then repeated this three more times to further purify the isolate. M. lylae can be distinguished from the closely related species Micrococcus luteus by lysozyme susceptibility, genetic composition, and the type of cell-wall peptidoglycan. Micrococcus luteus can synthesize the iso-branched and anteiso-branched alkenes by the head-to-head condensation of fatty-acid thioesters. Shape (Cocci/Diplococci/Rods) Cocci. An obligate aerobe, M. luteus is found in soil, dust, water and air, and as part of the normal microbiota of the mammalian skin. Following incubation at 37oC, if the plasma forms a clot, the organism is coagulase positive. 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 Catalase Test: The catalase test facilitates the detection of the enzyme catalase in bacteria. 2014). Annals of Allergy, Asthma and Immunology 122(1):17-24. Colonies typically have a lemon-yellow pigment. 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. Staphylococci were distinguished by their ability to form acid from glucose anaerobically and sarcinas by the formation of cubical packets. This can occur due to the presence of a reduced number of proteins that can bind to penicillin. Most of the species produce carotenoid pigments. Recent reports, however, confirm that micrococci may be associated with human infections, particularly in immunosuppressed patients. Growth can produce colonies of a certain size and consistency, as well as pigmentation. Is Micrococcus luteus indole positive? Micrococcus luteus is coagulase negative, bacitracin susceptible, and forms bright yellow colonies on nutrient agar. The colony morphology of being yellow, shiny and smooth line up perfectly with M. luteus (Public Health England). Oral microbial flora of reptiles includes bacteria from Proteus, Porphyromonas, Micrococcus, Salmonella and Staphylococcus genera 5,8,15. Wieser et al. Micrococcus luteus biochemical test result. 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. Micrococcus Luteus is a gram positive, non-motile, non-sporing cocci belonging to micrococcea family. Make a tape label writing the color dot, your name, and the name of the media. CATALASE TEST: Catalases are enzymes that convert hydrogen peroxide (H2O2) into water and oxygen gas. Organisms commonly found on the body include Micrococcus, Staphylococcus, and Corynebacterium species (Dermnet New Zeland). There are around nine species that are recognized in the genus. It has survived for at least 34,000 to 170,000 years, as assessed by 16S rRNA analysis, and possibly much longer. Ans: Although it is a harmless saprophyte, Micrococcus luteus can act as an opportunistic pathogen. The metabolic pathways required for biomass production in silico were determined based on earlier models of actinobacteria. I performed a Gram stain test to identify if the bacterium was gram negative or positive, as described in the Lab 4 handout. Micrococcus luteus, a commonly found member of the Micrococcaceae, produces round colonies which are convex (curving outward) with smooth, entire margins. Streptococcus spp. It is an opportunistic pathogen, only pathogenic enough to cause disease in weakened immune systems (Medical Laboratories). It shows that it is mostly Actinobacteria, with some firmicules ,and proteobacteria mixed in (Figure 2). Enterococcus faecalis. For example, M. luteus and M. lylae are 40-50% genetically different. For the detection of oxidase enzyme, filter paper circular disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride in dimethyl sulfoxide are used. 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. Micrococcus lutues are Gram positive cocci that are 0.5 to 3.5 m in diameter and arranged in tetrads or irregular clusters. The taxonomic assignment of this microbe was micrococcus luteus because it was the only bin that PATRIC gave. M. luteus is considered an opportunistic pathogen that can be responsible for some of the nosocomial infections. 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. All pathogenic strains of S. aureus are coagulase positive whereas the nonpathogenic species (S. epidermidis for example) are coagulase negative. If the infection leads to severe hemodynamic alterations, thus the valve replacement may become necessary. Micrococcus luteus is coagulase negative, bacitracin susceptible, and forms bright yellow colonies on nutrient agar. 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. // Basics of Differentiation of Gram Positive Cocci, Author: Karen Krisher In the final section of a study, it is essential to present important information, techniques, and variables. The streptococci and enterococci are categorized by expression of either beta, alpha, or gamma hemolysis on sBAP, depending on the genus/species. It had 27,372 contigs in assembly. Your email address will not be published. Required fields are marked *. This matches up with the PATRIC metagenome binning which also showed some impurities (Figure 1). The nasal cavity microbiota of healthy adults. 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. This bacterium is often arranged in the form of circular tetrads and it forms bright yellow colonies on nutrient agar. Intro: Microbes are everywhere, even in the most extreme environments and conditions. Genus: Micrococcus. 2-9 In these reports micrococci were identified on the basis of their . Bassis CM, AL Tang, VB Young, and MA Pynnonen (2014). The GC content of the DNA ranges from about 65 to 75 mol%. Micrococcus lylaeare Gram-positive cocci mostly arranged in tetrads. The gram stain of this microbe showed that it is gram positive because it stained purple. [7], In 2003, it was proposed that one strain of Micrococcus luteus, ATCC 9341, be reclassified as Kocuria rhizophila. Institute for Quality and Efficiency in Health Care. Maximum production of pigments was observed at 35C, pH 9 and at 4% (W/V) NaCl concentration. It may appear in irregular clusters, groups of four or eight. Though today the immuno-compromised patients take the risk of the infection that has grown. At U.S. Micro Solutions, our microbiology laboratory is a licensed, accredited source for thorough and accurate environmental testing . On this Wikipedia the language links are at the top of the page across from the article title. The results of these tests provide a biochemical profile, or "fingerprint," that can be used to classify or even identify the bacterial species. The colonies are a pale, translucent yellow, and are shiny when looked at in the light. M. luteus has a G-C content of about 65-75 mol%. Similar to the situation in the prosthetic valve endocarditis that is caused by more aggressive and highly resistant bacteria. 1. The API 20 Strep test I used came up with no conclusive results. 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). Abstract: Gliotoxin, an epipolythiodioxopiperazine, is a fungal metabolite that causes genomic DNA degradation preferentially in certain blood cell types including T lymphocytes and macrophages. 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. These results might not be trustworthy. The bacterium also colonizes the mouth, mucosae, oropharynx, and upper respiratory tract. The microscopic morphology of the organisms as visualized using the Grams stain can give initial clues as to the possible identification of the organism. The Micrococcus strains isolated from various infections were most probably misclassified as staphylococci. What are the Diseases that are Caused By Micrococcus? 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%. Microbiome 2(27). The organism itself is susceptible to almost all drugs, with a few strains being resistant to nitrofurantoin, macrolides and lincomycin (Public Health Canada). 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. They grow in circular, entire, convex, and creamy yellow-pigmented colonies with diameters of approximately 4 mm after 2-3 days at 37C. This is in agreement with a study by Mohana et al., (2013) who reported that the carotenoid pigments had antioxidant properties of Micrococcus luteus was reported at IC50 of 4.5mg/ml, also the . Micrococcus species, members of the family Micrococcaceae, are usually regarded as contaminants from skin and mucous membranes. Table 1: Graph from Korona showing the percent reads of each organism, and to which taxonomic level. 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. 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. The catalase and the oxidase tests came up negative, because the catalase test did not form bubbles, and the oxidase test did not see a color change. Reduction of O2 produces superoxide radicals and hydrogen peroxide, or the hydroxyl radical. "EPR and ENDOR detection of compound I from Micrococcus lysodeikticus catalase". Some of the Micrococcus are pigmented bacteria, for example, M. roseus produces reddish colonies and M. luteus produces yellow colonies. Care must be taken when using a sample of organism acquired from a sBAP since erythrocytes also produce catalase. This simple-to-perform test categorizes the Gram-positive cocci as either catalase producers (+) or non-producers (-). Catalase test was the first biochemical test to be done . The PYRA, PAL, LAP, RIB, ARA, MAN, and TRE tests came up as positive. M. luteus is the majority of reads on the species level. Beta-hemolysis is a defining characteristic of Staphylococcus aureus and a certain streptococci. You can change these settings at any time, but that may impair functionality on our websites. To identify our isolate after obtaining the pure culture, we performed many different tests. Micrococcus spp. These include the slide or drop catalase test, the tube method, the semiquantitative catalase for the identification of Mycobacterium tuberculosis. Exposure to these wavelengths of ultraviolet light has been correlated with an increased incidence of skin cancer, and scientists believe this pigment can be used to make a sunscreen that can protect against ultraviolet light.[9]. 1. 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. They are found in many other places in the, M. luteus has one of the smallest genomes of all the bacteria. The genera Staphylococcus, Micrococcus and Sarcina were recognized. After observation of the colony and microscopic morphology, the production of catalase by the isolate is documented. Date: FEB.11.2016 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. 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. The oxidase test was negative, as the strip did not change color at all, where it would have turned purple if it was positive. They contain cytochromes and are resistant to lysostaphin. The catalase test also indicated that the microbe does not have catalase, despite the metagenomic binning test suggesting it. 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. The bubbling reaction is almost immediate and distinct in appearance. 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. Take a clean, scratch free glass slide. 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). These organisms range in virulence potential from commensal organisms found on the skin and mucous membranes to pathogens associated with serious infections. The microbiome of the nose. Most of the bacterium in the gram stains were gram negative, but a significant amount, about twenty percent, showed up as gram positive. This bacterium can withstand massive doses of UV radiation and it also has the capability to degrade certain pollutants such as petrol. all 3 tests done w/SIM deeps just add Kovac's reagent for Indole test Alcaligenes faecalis (left) - . Although of low virulence, the germs may become more pathogenic in patients with impaired resistance, colonizing the surface of heart valves. All three types of hemolytic reactions are represented on this slide. 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 genome of the Micrococcus is rich in guanine and cytosine, they typically exhibit about 65 to 75% GC-content. 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. When looking back at all the data, it is fairly likely that the isolate is Micrococcus luteus, especially when looking at the fluid thyoglycate test, the colony morphology, and the antibiotic susceptibility. So far there are two genome sequences that have been done. The differentiation is based on the detection of the oxidase enzymes. 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. Source: Trainee Council in English, Hello, my name is Dr. Karen Krisher. Table 2: Graph of the genomic reads by taxonomic level using Korona. Micrococcus species by the Taxo A Bacitracin disk test can also be differentiated from staphylococcus species. 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. Colony pigmentation varies considerably but is usually different shades of yellow or cream-white. DNA release from the cell is coupled with adsorption of DNA onto a silica spin-column . 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. M. luteus can also cause septic shocks in immuno-compromised people. They are fairly ubiquitous in the environment, and are small (0.5 to 3.5 micrometers in diameter) and non-motile. Micrococcus varians Micrococcus luteus Staphylococcus saprophyticus Staphylococcus epidermidis Streptococcus pneumoniae Streptococcus mitis 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 grow in circular, entire, convex, and creamy yellow-pigmented colonies with diameters of approximately 4 mm after 2-3 days at 37C. The staphylococci and micrococci are catalase producers while the streptococci, enterococci, and a variety of other Gram-positive cocci are catalase-negative. M. luteus played an important part in Flemings discovery of Lysozyme which is the bodys natural antibiotic. The positive catalase result lines up with M. luteus (Public Health England). 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. Micrococcus luteus was formerly known as Micrococcus lysodeikticus. The pathogen, Staphylococcus aureus, is notably coagulase-positive while most other members of the family are coagulase-negative. As the microbe is gram positive this means that it has a large peptidoglycan layer and lacks a lipopolysaccharide layer. Because of their diversity, there are a variety of biochemical tests that are used by laboratories to identify the Gram-positive cocci. Micrococcus is a genus of bacteria that is present in the Micrococcaceae family. 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. [2] It resists antibiotic treatment by slowing of major metabolic processes and induction of unique genes[citation needed]. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Built with Enlightenment Theme and WordPress. [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]. 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. nishinomiyaensis and Micrococcus luteus. The optimum growth temperature is 25-37C. Micrococci may be distinguished from staphylococci by a modified oxidase test as shown below-. There have been several deaths in immuno-compromised children that are caused by leukemia from the pulmonary hemorrhages because of Micrococcus. I kept the plate at room temperature for 7 days, and then selected a colony to purify using the pure culture streak plate method. Coagulase Results: Micrococcus luteuswere discovered by Sir Alexander Fleming before he discovered penicillin in 1928. Motility (Motile / Non-Motile) Non-Motile. Hemolysis is the lysis of the sheep erythrocytes within the agar by bacterial toxins (hemolysins) that are produced by the different genera of Gram-positive cocci. (2019, April 4). // Staphylococci are either producers of the enzyme coagulase or non-producers. Lastly, do not underestimate the variety of different genera in the four families of the Gram- positive cocci that can, under the right circumstances, move from relatively harmless saprophytes to disease-producing opportunists. Note the bright yellow, non-diffusable colony pigment which is a defining characteristic of M. luteus. Book a free counselling session. They are seldom motile and are non-sporing. Staphylococcus spp. Growth or weak growth is observed at 45C, at pH 10, and in the presence of 10% sodium chloride (NaCl). 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.

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