Millions of microbes live both on and in the human body and can both make help us survive or make us sick, less than 1% of bacteria cause disease (What are microbes, 2010). They are positive for catalase and oxidase ( modified). Complete lysis of the erythrocytes in the vicinity of the growing colony. 2019). This bacterium is often arranged in the form of circular tetrads and it forms bright yellow colonies on nutrient agar. After observation of the colony and microscopic morphology, the production of catalase by the isolate is documented. On top of that, most of the bacterium that were stained were gram negative, which conflicts with this result. 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. 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. Environmental Testing. The modified oxidase reagent is prepared as tetramethyl-p-phenylenediamine in certified grade dimethyl sulfoxide. The catalase test also indicated that the microbe does not have catalase, despite the metagenomic binning test suggesting it. Other Micrococcus isolates produce various useful products, such as long-chain aliphatic hydrocarbons for lubricating oils. Wikipedia also says that Micrococcus luteus is an obligate aerobe, backing up what my results show (2019). 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. CCTC (English) Take a clean, scratch free glass slide. nishinomiyaensis and Micrococcus luteus. 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. It is often larger thanStaphylococcus. Micrococcus luteus is coagulase negative, bacitracin susceptible, and forms bright yellow colonies on nutrient agar. Source: Trainee Council in English, Hello, my name is Dr. Karen Krisher. Micrococcus species are oxidase-positive, where these can be used to distinguish them from some other bacteria like most of the Staphylococcus species, which are generally oxidase-negative. An interesting remaining family member, Microoccus antarcticus, was isolated from Antarctica, and is capable of growing at 4C. Genus: Micrococcus. M. luteus has a G-C content of about 65-75 mol%. This microbe forms large, round colonies. 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. The differentiation is based on the detection of oxidase enzyme. It is difficult to differentiate Kocuria from Micrococcus with conventional biochemical methods; therefore, these organisms are often reported together as Micrococcus/Kocuria species. Maximum production of pigments was observed at 35C, pH 9 and at 4% (W/V) NaCl concentration. They are indole negative, oxidase-positive, catalase-positive, and citrate negative. Figure 2. Your email address will not be published. Catalase, if present, will break down the hydrogen peroxide to water and oxygen. Catalase is an enzyme produced by the organism to neutralize the toxic effects of hydrogen peroxide in the environment of the cell. These include the slide or drop catalase test, the tube method, the semiquantitative catalase for the identification of Mycobacterium tuberculosis. They also produce yellow or pink colonies when they are grown on the mannitol salt agar, micrococcus flavus, M. terreus, and M. yunnanensis. Isolates of the M. luteus have been found to overproduce the riboflavin virus when they are grown on toxic organic pollutants like pyridine. So far there are two genome sequences that have been done. Three bacteria, E.coli, Staphylococcus epidermis, and Micrococcus luteus, have been grown on TSI or Triple sugar iron agar medium, which is a . It has survived for at least 34,000 to 170,000 years, as assessed by 16S rRNA analysis, and possibly much longer. All of these are described in the lab 6 handout and were kept in the incubator at 38 degrees Celsius. 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. 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. 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 API 20 E test strip results revealed nothing about what the isolate uses as an electron acceptor because every result was negative, and that it likely only uses glucose as an energy and carbon source and oxygen as its electron acceptor. Biochemical Tests in Microbiology answer sheet - Biochemical Tests in Microbiology Pre-Laboratory - Studocu Biochemical Tests in Microbiology lab answer sheet biochemical tests in microbiology questions why do some microbes specialize to use different food source than Skip to document Ask an Expert Sign inRegister Sign inRegister Home As its name suggests, mannitol salt agar (MSA) contains 1% mannitol (sugar), 7.5% salt, and agar as a solidifying agent. We found this to be true because the filter paper turned blue, which showed that the species has the cytochrome c oxidase enzyme. Micrococcus luteus in tetrads arrangement. Growth or weak growth is observed at 45C, at pH 10, and in the presence of 10% sodium chloride (NaCl). The bacterium also colonizes the mouth, mucosae, oropharynx, and upper respiratory tract. 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. When a drop of peroxide is placed on catalase-producing bacteria, bubbles appear when the oxygen gas is formed. 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. Your email address will not be published. Micrococci are microbiologically characterized as gram-positive cocci, 0.5 to 3.5 m (micrometres; 1 m = 10-6 metre) in diameter. 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 catalase test facilitates the detection of the enzyme catalase in bacteria. AACC.org 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 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. When viewing the organism microscopically, the staining characteristics of the organism provide important information for identification. The bacterium also colonizes the human mouth, mucosae, oropharynx and upper respiratory tract. The third image represents the colony morphology of many of the streptococci and enterococci. Micrococcus luteus has been shown to survive in oligotrophic environments for extended periods of time. I used an API Strep test to determine more of the sugars the bacteria could ferment. Intro: Microbes are everywhere, even in the most extreme environments and conditions. They are generally strict aerobes and can generally reduce nitrate. The staphylococci are characterized by the formation of clusters of many cocci. Biochemical 1- Catalase (+ve) 2- Coagulase (-ve) 2-9 In these reports micrococci were identified on the basis of their . 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. Bassis CM, AL Tang, VB Young, and MA Pynnonen (2014). CATALASE TEST: Catalases are enzymes that convert hydrogen peroxide (H2O2) into water and oxygen gas. 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). Whereas the M. variant has a G-C content of about 66-72mol%. They are also catalase-positive and often weakly oxidase-positive ( modified oxidase test positive). Abstract Micrococcus luteus IFO 3333 cells, both treated with chemical reagents and non-treated, were observed with a scanning electron microscope (SEM). 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 species, members of the family Micrococcaceae, are usually regarded as contaminants from skin and mucous membranes. Obtain a glucose fermentation tube. Culture Characteristics: Colonies are shades of yellow or red. Shape (Cocci/Diplococci/Rods) Cocci. The colonies are a pale, translucent yellow, and are shiny when looked at in the light. M. luteus played an important part in Flemings discovery of Lysozyme which is the bodys natural antibiotic. It has been isolated from human skin. I think that this culture was mostly Micrococcus luteus based on the Kaiju and metagenome binning results. What are the Uses of Micrococcus Gram Stain? Ans: Although it is a harmless saprophyte, Micrococcus luteus can act as an opportunistic pathogen. We will discuss this shortly. Micrococcus has a substantial cell wall in which it may comprise as much as 50% of the cell mass. Once the culture was deemed pure enough, I inoculated a slant tube. The coagulase test is performed by mixing a sample of organism with rabbit plasma. This bacterium can withstand massive doses of UV radiation and it also has the capability to degrade certain pollutants such as petrol. 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. I kept the plate at room temperature for 7 days, and then selected a colony to purify using the pure culture streak plate method. It is a gram positive, coccus shaped microbe, and contains catalase. Alcaligenes faecalis Bacillus megaterium . M. luteus is considered an opportunistic pathogen that can be responsible for some of the nosocomial infections. Oxidase (modified oxidase) test: Positive. [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 catalase-positive and usually aerobic with strictly respiratory metabolism. 1 Nevertheless they have been documented to be causative organisms in cases of bacteremia, endocarditis, ventriculitis, peritonitis, pneumonia, endophthalmitis, keratolysis and septic arthritis. Micrococcus luteus biochemical test result. 2. Subscribe to our e-mail newsletter to receive updates. There are 3 biovars of this organismand they possess quite diverse chemotaxonomic features with respect to their menaquinone systems, cell-wall compositions, and Fourier transform-infrared (FT-IR) spectroscopy patterns, as well as biochemical properties. Only the Micrococcus luteus species contained cytochrome c oxidase. M. luteus is found in the soil, dust, water, and human skin flora. Last updated: August 10, 2022 by Sagar Aryal. They also produce yellow or pink colonies when they are grown on the mannitol salt agar, micrococcus flavus, M. terreus, and M. yunnanensis. The data on the GC content of the DNA, chemical cell wall analysis, and a comparative analysis of the 16S rRNA sequences. Alpha-hemolytic colonies often assume a greenish hue. Some of the species of Micrococcus, such as M. luteus which is yellow in colour, and M. roseus which is red. 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. Each genus lends itself to a separate tutorial. Is Micrococcus luteus indole positive? They are considered as normal comensal of human skin and upper respiratory tract. Biochemical Test and Identification of Staphylococcus aureus. Micrococcus luteus uses the amino acids and does not grow in the butt of the slant. Institute for Quality and Efficiency in Health Care. This is likely either a cause of human error, unpure cultures, or not using agar plates that are fresh enough for the test. It shows that the sample contains bacteria from the Terrabacteria group. It shows that it is mostly Actinobacteria, with some firmicules ,and proteobacteria mixed in (Figure 2). The mammalian skin that has M. luteus strain is also highly sensitive to the beta-lactam antibiotics. Oral microbial flora of reptiles includes bacteria from Proteus, Porphyromonas, Micrococcus, Salmonella and Staphylococcus genera 5,8,15. 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. 2023 Universe84a.com | All Rights Reserved, Blog: Microbiology and infectious disease, Anti-Mullerian Hormone (AMH) Test: Introduction, Result, Unit, Normal Range, Test Method, Clinical Significance, and Keynotes, Anti -TPO Antibody: Introduction, Test Result, Unit, Normal Range, Assaying Method, and Keynotes, HPV Genes detection using Real-Time PCR: Introduction, Principle, Test Requirements, Procedure, Result Interpretation and Keynotes, Microbiology Reporting Techniques: Introduction, List of Templates, and Keynotes, Acetamide Utilization Test: Introduction, Composition, Principle, Test Requirements, Procedure, Result-Interpretation, Limitations, and Keynotes, https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/887570/UK_SMI_ID_07i4.pdf, https://en.wikipedia.org/wiki/Micrococcus_luteus, https://europepmc.org/article/med/14576986, https://www.ajicjournal.org/article/S0196-6553(13)01146-2/fulltext. They are catalase and oxidase positive whereas urease negative. Like MSA, this medium also contains the pH indicator, phenol red. The tetrads of the micrococci, the grape like clusters of the staphylococci, and the pairs and/or chains of the streptococci are shown. Therefore I used this as my location to take my environmental sample from. It is reported here that gliotoxin selectively spares a unique class of haemopoietic stem cell that forms large (HPP) colonies in the presence of mixtures of MCSF and IL3. Micrococcus species are more sensitive to the Bacitracin while the staphylococci are resistant. In the final section of a study, it is essential to present important information, techniques, and variables. The partial decomposition of the hemoglobin of the erythrocytes by a weaker hemolysin. Some Micrococcus are pigmented bacteria; for example, M. luteus produces yellow colonies and M. roseus produces redish colonies. 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. 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. About half of the Micrococcus luteus gram stain was found to carry plasmids of about one to 100MDa in size. The colony took 16 days to be purified. When performing tests for physiological traits, the results were limited. Micrococcaceae. Similar to the situation in the prosthetic valve endocarditis that is caused by more aggressive and highly resistant bacteria. Micrococcus luteus is another gram-positive coccus that also is catalase positive. Enter the email address you signed up with and we'll email you a reset link. The microdase test is a rapid method to differentiate Staphylococcus (-ve) from Micrococcus +ve) by detection of the enzyme oxidase. Cells are catalase positive, oxidase positive, and exhibit strictly aerobic metabolism. Most of the bacterium in the gram stains were gram negative, but a significant amount, about twenty percent, showed up as gram positive. 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 Bacillus megaterium fermented sugars but didn't grow in the anaerobic area of the butt. 900 Seventh Street, NW Suite 400 They occur in pairs, tetrads or clusters but not in chains. Micrococci have Gram-positive spherical cells ranging from about 0.5 to 3 micrometers in diameter and typically appear in tetrads. The micrococci produce tetrads consisting of 4 cocci clustered together. The catalase test tests to see if the microbe contains catalase. They are seldom motile and are non-sporing. I used the Kirby-Bauer, or disk diffusion test to test for this, described in lab handout 9. Micrococcus luteus. Colonies typically have a lemon-yellow pigment. Intermediates or end products of these varied metabolic activities can be detected by performing biochemical assays on a bacterial culture. . AACC uses cookies to ensure the best website experience. 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. The oxidase test results suggest that the microbe does not contain oxidase, despite what the metagenome binning test showed. 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). This is a test for aerobic (able to use oxygen) catalase-positive bacteria such as Staphylococcus and Micrococcus. Basics of Differentiation of Gram Positive Cocci, Author: Karen Krisher "Pathogen Safety Data Sheets: Infectious Substances Micrococcus spp", "Genome sequence of the Fleming strain of Micrococcus luteus, a simple free-living actinobacterium", "Role of GC-biased mutation pressure on synonymous codon choice in Micrococcus luteus, a bacterium with a high genomic GC-content", "Reclassification of ATCC 9341 from Microccus luteus to Kocuria rhizophila", https://en.wikipedia.org/w/index.php?title=Micrococcus_luteus&oldid=1132534318, Articles with unsourced statements from January 2023, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 9 January 2023, at 09:24. Enterobacter aerogenes fermented the sugars but turned to the amino acids. Micrococcus varians Micrococcus luteus Staphylococcus saprophyticus Staphylococcus epidermidis Streptococcus pneumoniae Streptococcus mitis 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. If acid is produced, the pH indicator will turn yellow. They are catalase positive and often oxidase positive although this reaction may be weak (see Table 23.3 ). Hybridization studies indicate that species within the genus Micrococcus are not closely related, showing as little as 50% sequence similarity. The differentiation of the Gram-positive cocci encompasses 4 main exercises used to compare and contrast the characteristics of each family: These four tests will, as we shall see, allow for the differentiation of the families of organisms and will guide the laboratorian to other more definitive tests for the identification of the organism. This bacterium can also be transmitted to others due to poor hand-washing practices. 2. 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. 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. In Wikipedia, The Free Encyclopedia. They are generally strict aerobes and can generally reduce nitrate. Micrococcus spp. If the infection leads to severe hemodynamic alterations, thus the valve replacement may become necessary. Know more about our courses. I also did a fluid thioglycolate test to determine the bacterias oxygen class. 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. The results of this analysis are shown in table 1. 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%. 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. All three types of hemolytic reactions are represented on this slide. luteus is capable of surviving in environments 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 . Hybridization studies show that there is no close genetic relationship between the species of Micrococcus bacteria. On this Wikipedia the language links are at the top of the page across from the article title. It has multiple antibiotic resistance genes including dihydropteroate synthase, glycerophosphoryl diester phosphodiesterase, and SSU ribosomal proteins. Depend on Gram stain Test and Biochemical Test find four species of cellulolytic bacteria such as Bacillus subtilis, Pseudomonas diminuta, Micrococcus luteus and Plesiomonas shigelloides. Micrococcus luteus was formerly known as Micrococcus lysodeikticus. Streptococci and enterococci are observed to produce pairs and chains of cocci of varying length. November 27, 2021 at 9:14 AM Hi sir, why Macrococcus and Micrococcus will not ferment . . About half of the Micrococcus luteus gram stain was found to carry plasmids of about one to 100MDa in size. 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. 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. The sample was then sequenced using the Illumina MiSeq technology in UAFs DNA Core Lab. Baird-Parker, A. c.: A classification of micrococci and staphylococci based on physiological and biochemical tests. Download Scientific Diagram from www.researchgate.net. 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. 2002). The genome of the Micrococcus is rich in guanine and cytosine, they typically exhibit about 65 to 75% GC-content. The EMB agar showed no growth or change in color, also indicating the microbe was gram positive and a non-fermenter. 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]. Mannitol salt agar (MSA) is a selective, differential, and indicator medium used to isolate and identify Staphylococcus aureus from the clinical specimen. With the advent of newer molecular techniques, genus and species confirmation is even faster and easier. It may appear in irregular clusters, groups of four or eight. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Built with Enlightenment Theme and WordPress.