To identify our isolate after obtaining the pure culture, we performed many different tests. In conclusion, some of my results were inconclusive and conflicting. (2019, April 4). The bacterium also colonizes the mouth, mucosae, oropharynx, and upper respiratory tract. Micrococcus luteus is generally harmless but can become an opportunistic pathogen in immunocompromised people or those with indwelling catheters. It is an aerobic exopolysaccharide producing bacteria that may be found on the skin, mouth and sometimes in the throat of mammals 13,14. A positive test leads to the development of blue or purple-blue on the disc within two minutes. They are generally strict aerobes and can generally reduce nitrate. Staphylococcus spp. Micrococcus luteus uses the amino acids and does not grow in the butt of the slant. Note the bright yellow, non-diffusable colony pigment which is a defining characteristic of M. luteus. 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. Micrococcus Luteus is a gram positive, non-motile, non-sporing cocci belonging to micrococcea family. ? all 3 tests done w/SIM deeps just add Kovac's reagent for Indole test Alcaligenes faecalis (left) - . Cultures:- Nutrient broth cultures of Micrococcus luteus and Proteus vulgaris (young cultures) Procedure: Wet Mount Preparation . The bubbling reaction is almost immediate and distinct in appearance. All pathogenic strains of S. aureus are coagulase positive whereas the nonpathogenic species (S. epidermidis for example) are coagulase negative. Streptococci and enterococci are observed to produce pairs and chains of cocci of varying length. If I were to continue researching this isolate, I would redo the API 20 E test strip with a fresh, active culture to ensure that it can reduce nitrate, and also the oxidase test to ensure that it does have cytochrome c oxidase present, which it should according to Public Health England. Habitat Micrococcus lives in a wide range of environments such as water, soil, and the dust whereas, Staphylococcus lives in the animal body. I grew my isolated in Tryptic Soy Broth (TSB) for a week to prepare for DNA extraction. //
Mannitol salt agar (MSA) is a selective, differential, and indicator medium used to isolate and identify Staphylococcus aureus from the clinical specimen. Micrococcus species are oxidase-positive, which can be used to distinguish them from other bacteria like most Staphylococcus species, which are generally oxidase-negative. These results might not be trustworthy. This microbe forms large, round colonies. This kit utilizes enzymatic reactions to release bacterial DNA from the cell. Like all Staphylococci, S. saprophyticus is also clustering Gram-positive cocci, nonmotile, non-spore-forming, and . Only those with compromised immune systems are thought to be susceptible to an infection.DisinfectionM. Micrococcus luteus, a commonly found member of the Micrococcaceae, produces round colonies which are convex (curving outward) with smooth, entire margins. Most of these are mesophiles; some, like Micrococcus antarcticus which is found in Antarctica, are psychrophiles. Although it's tempting to write a summary of the entire study but it . The third image represents the colony morphology of many of the streptococci and enterococci. They are also catalase-positive and often weakly oxidase-positive ( modified oxidase test positive). Following incubation at 37oC, if the plasma forms a clot, the organism is coagulase positive. 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).
Table 1: Graph from Korona showing the percent reads of each organism, and to which taxonomic level. Environmental Testing. Staphylococcus spp. Of those only Vancomycin was closer than 50 millimeters, being 38 millimeters. Microbiome 2(27). 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. This is termed alpha () hemolysis and results in a greenish color surrounding the colony.
This is designated as beta ()-hemolysis. The micrococci produce tetrads consisting of 4 cocci clustered together. 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. The catalase test facilitates the detection of the enzyme catalase in bacteria. Like MSA, this medium also contains the pH indicator, phenol red. Label the slide with the name of the organism; Place 15 - 20 uL of the culture in the middle of the slide Micrococcus species are more sensitive to the Bacitracin while the staphylococci are resistant. The differentiation is based on the detection of the oxidase enzymes. They are fairly ubiquitous in the environment, and are small (0.5 to 3.5 micrometers in diameter) and non-motile. I performed many tests to find out the colony morphology and physiology. I then transferred the pure culture into a TSB slant to preserve it, keeping it at around 3 degrees Celsius in the lab refrigerator. Enter the email address you signed up with and we'll email you a reset link. Micrococcus also not able to ferment glucose anaerobically (negative) Reply. Micrococcus luteus | Taxonomy - PubChem Apologies, we are having some trouble retrieving data from our servers. Source publication +9 Isolation and Identification of Potential Pathogenic Bacteria in Living Carp (Cyprinus carpio Linnaeus, 1758) Sold in. 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. Examples of the colony morphology associated with each family is 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. They are generally strict aerobes and can generally reduce nitrate. Enterococcus spp. 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. Catalase is an enzyme produced by the organism to neutralize the toxic effects of hydrogen peroxide in the environment of the cell. Last updated: August 10, 2022 by Sagar Aryal. M. luteus oxidizes carbohydrates to CO2 and water, and it does not produce acid from glucose as well as it does not make arginine dihydrolase or b-galactosidase. luteus is rarely found to be responsible for infections. 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. Whereas the M. variant has a G-C content of about 66-72mol%. This microbe is coccus shaped and forms in tetrads. 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. They contain cytochromes and are resistant to lysostaphin. For example, Micrococcus varians is now known as Kocuria varians. Bacteria Collection: Micrococcus luteus Additional Information. The Micrococcus strains isolated from various infections were most probably misclassified as staphylococci. So far there are two genome sequences that have been done. The oxygen class and the gram positiveness of the microbe also matches up with that of Micrococcus luteus. Oxidase (modified oxidase) test: Positive. 2002). This is a test for aerobic (able to use oxygen) catalase-positive bacteria such as Staphylococcus and Micrococcus. From: Infectious Diseases (Third Edition), 2010 View all Topics About this page
The pathogen, Staphylococcus aureus, is notably coagulase-positive while most other members of the family are coagulase-negative. 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. 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 . However, the most promising antibiotic regimen that is proposed for the treatment of the Micrococcus luteus seems to be a combination of amikacin, vancomycin, and rifampicin. 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. 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. This would be read A/NC. This bacterium can withstand massive doses of UV radiation and it also has the capability to degrade certain pollutants such as petrol. M. luteus present on the human skin can transform compounds present in sweat into compounds with an unpleasant odour. Micrococcus luteus. 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. These discrepancies could be due to human error, unpure culture, or an old agar plate. 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. 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. When viewing the organism microscopically, the staining characteristics of the organism provide important information for identification. //
Though today the immuno-compromised patients take the risk of the infection that has grown. Micrococcus Luteus 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 enzymes. Micrococcus is a genus of bacteria that is present in the Micrococcaceae family. We found this to be true because the filter paper turned blue, which showed that the species has the cytochrome c oxidase enzyme. 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. 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. [1] It is urease and catalase positive. [2] It resists antibiotic treatment by slowing of major metabolic processes and induction of unique genes[citation needed]. It grew in circular, entire, convex and creamy yellow pigmented colonies heaving 0.5-2.5 diameter. 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]. [7], In 2003, it was proposed that one strain of Micrococcus luteus, ATCC 9341, be reclassified as Kocuria rhizophila. All of these are described in the lab 6 handout and were kept in the incubator at 38 degrees Celsius. 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. 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. 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. 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 EMB agar showed no growth or change in color, also indicating the microbe was gram positive and a non-fermenter. They grow in circular, entire, convex, and creamy yellow-pigmented colonies with diameters of approximately 4 mm after 2-3 days at 37C.
Some Micrococcus are pigmented bacteria; for example, M. luteus produces yellow colonies and M. roseus produces redish colonies. For example, M. luteus and M. lylae are 40-50% genetically different. They are generally strict aerobes and these can generally reduce nitrate concentration. Micrococcus varians Micrococcus luteus Staphylococcus saprophyticus Staphylococcus epidermidis Streptococcus pneumoniae Streptococcus mitis Finally, when looking at the API 20E strip none of the results returned positive despite the culture being active and fresh from being streaked recently. Micrococcus species by the Taxo A Bacitracin disk test can also be differentiated from staphylococcus species. 2. J Gen Microbiol 30(1963)409-427 . They are fairly small as well, usually about a millimeter in diameter and of a normal height. It is Gram positive, Coagulase positive, catalase and oxidase positive non-motile bacteria. The GC content of the DNA ranges from about 65 to 75 mol%. Micrococcus spp. The confidence on that reading is decently confident, evidenced by the blue coloring. For example, M. luteus and M. lylae are 40-50% genetically different. M. luteus tests positive for catalase, oxidase, utilization of D-glucose, sucrose and D-mannose, and has A2 type peptidoglycan that contains L-lysine as the diagnostic amino acid, MK-8 and MK-8 (H 2) are the major menaquinones (Stackebrandt et al. Micrococcus was first isolated by Alexander Fleming in 1929, as Micrococcus lysodeikticus before it was known as micrococcus luetus (Ganz et al, 2002) Micrococcus is generally thought of as harmless bacterium, but there have been rare cases of Micrococcus infections in people with compromised immune systems, as occurs with HIV patients. 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. Oral microbial flora of reptiles includes bacteria from Proteus, Porphyromonas, Micrococcus, Salmonella and Staphylococcus genera 5,8,15. Micrococcus luteus. Kaiju webserver metagenome binning analysis chart. (2019, March 14). 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. 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). All three types of hemolytic reactions are represented on this slide. Abstract: Gliotoxin, an epipolythiodioxopiperazine, is a fungal metabolite that causes genomic DNA degradation preferentially in certain blood cell types including T lymphocytes and macrophages.
It has survived for at least 34,000 to 170,000 years, as assessed by 16S rRNA analysis, and possibly much longer. 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 is a spherical bacterium found on dead or decaying organic matter while Staphylococcus is a gram-positive bacterial genus that produces a bunch of grape-like bacterial clusters. M. luteus is found in the soil, dust, water, and human skin flora. Micrococcus luteus is coagulase negative, bacitracin susceptible, and forms bright yellow colonies on nutrient agar. 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 oxidase test results suggest that the microbe does not contain oxidase, despite what the metagenome binning test showed. 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. 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. Growth can produce colonies of a certain size and consistency, as well as pigmentation. . A very important test in the categorization of the staphylococci is the coagulase test. luteus is capable of surviving in environments Date: FEB.11.2016
The mammalian skin that has M. luteus strain is also highly sensitive to the beta-lactam antibiotics. The configurations are the result of the plane of cellular division exhibited by the organism. Luteus is an obligate aerobe (medical. It is essential for differentiating catalase-positive Micrococcaceae from catalase-negative Streptococcaceae. The microdase test, also known as modified oxidase test is a rapid test to differentiate Staphylococcus from Micrococcus which are Gram-positive cocci possessing catalase enzymes. Micrococcus species, members of the family Micrococcaceae, are usually regarded as contaminants from skin and mucous membranes. //
The tetrads of the micrococci, the grape like clusters of the staphylococci, and the pairs and/or chains of the streptococci are shown. Micrococci have Gram-positive spherical cells ranging from about 0.5 to 3 micrometers in diameter and typically appear in tetrads. 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. While defining the characteristics of the Micrococcus are the ability to produce acid aerobically from the aesculin hydrolysis, glucose glycerol, arginine dihydrolase, motility, major pigment production, and conversion of nitrate to nitrite. I also did a fluid thioglycolate test to determine the bacterias oxygen class. AACC uses cookies to ensure the best website experience. 900 Seventh Street, NW Suite 400 The catalase test also indicated that the microbe does not have catalase, despite the metagenomic binning test suggesting it. 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. 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). 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).
Micrococcus luteus has been shown to survive in oligotrophic environments for extended periods of time. Discussion: When looking at all of the results for my isolate, they are not all consistent with Micrococcus luteus. The catalase test tests to see if the microbe contains catalase. Hybridization studies show that there is no close genetic relationship between the species of Micrococcus bacteria. 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. 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. 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 . Recent reports, however, confirm that micrococci may be associated with human infections, particularly in immunosuppressed patients. 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. Is Micrococcus luteus indole positive? Streptococcus spp. 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 . It is mostly Actinobacteria, but some Proteobacteria and Firmicules are in the sample as well. Streptococcus pneumoniae and a group of streptococci referred to as viridans (green) streptococci are examples of bacteria producing alpha-hemolysis. M. luteus has one of the smallest genomes of actinobacteria with a circular chromosome of 2,501,097 base pairs and a GC content of 73%. The categorization of the Gram-positive cocci based on their possession of the enzyme catalase, a quality which can be easily assayed in the lab. The mammalian skin that has M. luteus strain is also highly sensitive to the beta-lactam antibiotics. The reactions of the four isolates indicated that they belonged to the species M. Zuteus (Kocur & Martinec, 1972). It is essential for differentiating catalase-positive Micrococcaceae from catalase-negative Streptococcaceae. . are gram-positive, oxidase-positive, and strictly they are aerobic cocci that are belonging to the family Micrococcaceae. 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. Micrococci have Gram-positive types of spherical cells that are ranging from about 0.5 to three micrometres in diameter and typically they appear in tetrads. Genus: Micrococcus. It shows that the sample contains bacteria from the Terrabacteria group. Then to actually isolate a bacterium, I chose a colony from the initial plate and did a quadrant streak of it to further isolate the bacterium, and then incubated it at 38 degrees Celsius for a week. (negative). Micrococcus luteus pigment (Yellow) GLUCOSE FERMENTATION TEST This test detects the ability of the bacterium to break down glucose to pyruvic acid. 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 previous classification of these organisms was much simpler; however, with the use of more advanced genetic sequencing methods, these gram-positive cocci have expanded into 4 separate families and their associated genera. The first control consisted of plates of agar-agar to test sterility. M. lylae can be distinguished from the closely related species Micrococcus luteus by lysozyme susceptibility, genetic composition, and the type of cell-wall peptidoglycan. The taxonomic assignment of this microbe was micrococcus luteus because it was the only bin that PATRIC gave. The colonies are a pale, translucent yellow, and are shiny when looked at in the light. M. luteus causes odours in humans when breaking down the components of sweat. Most of the species produce carotenoid pigments. As mentioned, the type of hemolytic reaction produced on sBAP is a major clue toward the identification of the genus. 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. 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). [3] The bacterium also colonizes the human mouth, mucosae, oropharynx and upper respiratory tract. Maximum production of pigments was observed at 35C, pH 9 and at 4% (W/V) NaCl concentration. Another test I did to identify my isolate was DNA analysis, described in lab handouts 5 and 7. (2010) What are microbes? Make a tape label writing the color dot, your name, and the name of the media. Micrococcus luteus can synthesize the iso-branched and anteiso-branched alkenes by the head-to-head condensation of fatty-acid thioesters. Wikipedia also says that Micrococcus luteus is an obligate aerobe, backing up what my results show (2019).
This bacterium is often arranged in the form of circular tetrads and it forms bright yellow colonies on nutrient agar. Evaluation of Antibacterial Properties of Iranian Medicinal-Plants against Micrococcus Luteus, Serratia Marcescens, Klebsiella Pneumoniae and Bordetella Bronchoseptica.. 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. Micrococcus as the cause of infections is easy to overlook because the infections that are caused by this bacterium are rare as well as the bacterium is a natural part of the skin's bacterial flora. The agglutinability of the cells with antiserum containing anti-teichuronic acid antibody was examined. 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 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). After observation of the colony and microscopic morphology, the production of catalase by the isolate is documented. Sarah D. Perkins., Government of Canada, Public Health Agency of Canada.
If the agar plate is held up to a light source, you can sometimes see through the agar, as is pictured on the left. 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. On this Wikipedia the language links are at the top of the page across from the article title. Though today the immuno-compromised patients take the risk of the infection that has grown.
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