micrococcus luteus biochemical tests

All three types of hemolytic reactions are represented on this slide. The species Micrococcus luteus (Schroeter 1872) Cohn 1872 (Approved Lists 1980) emend. For example, Micrococcus varians is now known as Kocuria varians. The pathogen, Staphylococcus aureus, is notably coagulase-positive while most other members of the family are coagulase-negative. The EMB plate is also selective for gram-negative bacteria which is probably why the bacteria didnt grow on it. The differentiation is based on the detection of oxidase enzyme. Micrococcus species, members of the family Micrococcaceae, are usually regarded as contaminants from skin and mucous membranes. Micrococcus luteus is another gram-positive coccus that also is catalase positive. The first control consisted of plates of agar-agar to test sterility. For the second control, 100 L of water sample dilutions were plated on agar-agar. Rawis M, and AK Ellis (2019). 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. The oxidase test was negative, as the strip did not change color at all, where it would have turned purple if it was positive. Due to the thick structure of the bacterial cell wall, Gram-positive cocci retain the primary Grams stain, Crystal Violet. Micrococci may be distinguished from staphylococci by a modified oxidase test as shown below-. The bubbling reaction is almost immediate and distinct in appearance. It is a gram positive, coccus shaped microbe, and contains catalase. (2) Micrococcus spp. "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. Filter paper disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride (oxidase reagent) in dimethyl sulfoxide (DMSO) are used. Where the M. luteus can cause severe skin infections and is sometimes clinically mistaken for Staphylococcus aureus. With the advent of newer molecular techniques, genus and species confirmation is even faster and easier. They are indole negative, oxidase-positive, catalase-positive, and citrate negative. Micrococcus luteusare Gram-positive cocci mostly arranged in tetrads and larger than Staphylococcus. The genus Micrococcus consists of Gram-positive spheres occurring in tetrads and in irregular clusters that are usually non-motile and non-spore-forming. There are around nine species that are recognized in the genus. What are the Diseases that are Caused By Micrococcus? (2019, April 4). M. luteus has one of the smallest genomes of all the bacteria. The microbiome of the nose. 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. Source: Trainee Council in English, Hello, my name is Dr. Karen Krisher. In the case of a negative test, no colour change is observed. Biochemical Test and Identification of Staphylococcus aureus. 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. Micrococcus species by the Taxo A Bacitracin disk test can also be differentiated from staphylococcus species. For the detection of oxidase enzyme, filter paper circular disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride in dimethyl sulfoxide are used. Growth or weak growth is observed at 45C, at pH 10, and in the presence of 10% sodium chloride (NaCl). They are found in soil, dust, water and air, and as part of the normal microbiota of skin. Micrococcus Luteus is a gram positive, non-motile, non-sporing cocci belonging to micrococcea family. This matches up with the PATRIC metagenome binning which also showed some impurities (Figure 1). Coagulase production is used as a virulence factor by the organism. Another test I did to identify my isolate was DNA analysis, described in lab handouts 5 and 7. 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. I also did a fluid thioglycolate test to determine the bacterias oxygen class. In the final section of a study, it is essential to present important information, techniques, and variables. Colony morphology, the elucidation of the characteristics of the growth of the bacterium on agar medium, in most cases trypticase soy agar containing 5% sheep blood (sBAP). 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. Some of the species of Micrococcus, such as M. luteus which is yellow in colour, and M. roseus which is red. Micrococcus spp. Continuing without changing cookie settings assumes you consent to our use of cookies on this device. ? Source publication +9 Isolation and Identification of Potential Pathogenic Bacteria in Living Carp (Cyprinus carpio Linnaeus, 1758) Sold in. In the case of a negative test, no colour change is observed. Whereas the M. variant has a G-C content of about 66-72mol%. The catalase test facilitates the detection of the enzyme catalase in bacteria. This technique is centered on the performance of the classic Grams stain. The optimum growth temperature is 25-37C. Microbiome 2(27). They are found in many other places in the, M. luteus has one of the smallest genomes of all the bacteria. For the micrococci, susceptibility to the antimicrobial agents, bacitracin and furazolidone, as well as the modified oxidase test can be performed to distinguish this group from the staphylococci. Positive. 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. 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. These residential skin organisms are also fairly ubiquitous in the environment. Cultures:- Nutrient broth cultures of Micrococcus luteus and Proteus vulgaris (young cultures) Procedure: Wet Mount Preparation . It is a gram positive, coccus shaped microbe, and contains catalase. This kit utilizes enzymatic reactions to release bacterial DNA from the cell. 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. They are considered as normal comensal of human skin and upper respiratory tract. The typical microscopic morphology of the Gram-positive cocci when using the Grams stain is represented in these three images. The nasal cavity microbiota of healthy adults. Structure and PhysiologyThis bacteria is Gram-positive, spherical, and an obligate aerobe. It shows that it is mostly Actinobacteria, with some firmicules ,and proteobacteria mixed in (Figure 2). When performing tests for physiological traits, the results were limited. Micrococcus luteus, a commonly found member of the Micrococcaceae, produces round colonies which are convex (curving outward) with smooth, entire margins. I kept the plate at room temperature for 7 days, and then selected a colony to purify using the pure culture streak plate method. I used an API Strep test to determine more of the sugars the bacteria could ferment. They can be found in boiling hot springs; they can be found in frigid waters in the artic. 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. It is essential for differentiating catalase-positive Micrococcaceae from catalase-negative Streptococcaceae. The API test strips lack of results suggests that the I used the wrong test strip, I probably needed to use the Staph test instead of the Strep test, because the Strep test is for when Catalase is absent, but there could have been catalase present. See answer (1) best answer. 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. The catalase test tests to see if the microbe contains catalase. 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. 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. luteus is capable of surviving in environments Obtain a glucose fermentation tube. 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. The differentiation is based on the detection of the oxidase enzymes. Each family of Gram-positive cocci has its own unique configuration. Similar to the situation in the prosthetic valve endocarditis that is caused by more aggressive and highly resistant bacteria. 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. [2] It resists antibiotic treatment by slowing of major metabolic processes and induction of unique genes[citation needed]. 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. This test had VP, HIP, ESC, PYRA, aGAL, bGUR, bGAL, PAL, LAP, ADH, RIB, ARA, MAN, SOR, LAC, TRE, INU, RAF, AMD, and GLYG tests. Required fields are marked *. Some Micrococcus are pigmented bacteria; for example, M. luteus produces yellow colonies and M. roseus produces redish colonies. 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. 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. Table 2: Graph of the genomic reads by taxonomic level using Korona. CCTC (English) From four species that have been identify, only Bacillus subtilis and Pseudomonas diminuta that show ability to block pathogen bacteria Edwardsiella tarda. It can be easily be mistaken for staphylococci, as they are very similar morphologically and physiologically (Wikipedia, Staphlyococcus Aureus). On top of that, most of the bacterium that were stained were gram negative, which conflicts with this result. I used the PATRIC software to perform a metagenome binning and to assign a taxonomy to the bacteria. Download Scientific Diagram from www.researchgate.net. It is Gram positive, Coagulase positive, catalase and oxidase positive non-motile bacteria. Streptococci and enterococci are observed to produce pairs and chains of cocci of varying length. Last updated: August 10, 2022 by Sagar Aryal. For example, M. luteus and M. lylae are 40-50% genetically different. // 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. Micrococcus varians Micrococcus luteus Staphylococcus saprophyticus Staphylococcus epidermidis Streptococcus pneumoniae Streptococcus mitis 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. They are fairly ubiquitous in the environment, and are small (0.5 to 3.5 micrometers in diameter) and non-motile. This lines up with M. luteus resistances from the tests. This microbe forms large, round colonies. Organisms commonly found on the body include Micrococcus, Staphylococcus, and Corynebacterium species (Dermnet New Zeland). 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. Micrococcus luteus biochemical test result. The configurations are the result of the plane of cellular division exhibited by the organism. 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. 1. 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. I repeated this process three more times to further purify the colony. The kaiju metagenome binning shows that the microbe sample is not completely pure (Figure 2). Biochemical 1- Catalase (+ve) 2- Coagulase (-ve) 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. If acid is produced, the pH indicator will turn yellow. 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. 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. 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. They are positive for catalase and oxidase ( modified). Annals of Allergy, Asthma and Immunology 122(1):17-24. 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. Hybridization studies indicate that species within the genus Micrococcus are not closely related, showing as little as 50% sequence similarity. Micrococcus luteus was one of the early examples of novel codon usage,[5][6] which led to the conclusion that the genetic code is not static, but evolves. They can even survive in conditions that have very little of even no oxygen, using glycolysis and alternative electron acceptors to create ATP. 2. Intermediates or end products of these varied metabolic activities can be detected by performing biochemical assays on a bacterial culture. Pearls of Laboratory Medicine This bacterium can withstand massive doses of UV radiation and it also has the capability to degrade certain pollutants such as petrol. Bacteria Detail., The Editors of Encyclopdia Britannica. The taxonomic assignment of this microbe was micrococcus luteus because it was the only bin that PATRIC gave. The partial decomposition of the hemoglobin of the erythrocytes by a weaker hemolysin. 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. 570 . When looking at the genetic tests, most of the identified strains in the Korona test are Micrococcus luteus. 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. Benecky M. J.; Frew J. E.; Scowen N; Jones P, Hoffman B. M (1993). 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. In conclusion, some of my results were inconclusive and conflicting. The colony morphology is the same as well, being round, shiny, and sort of flat (Medical Laboratories). Gram Staining. The negative oxidase result conflicts with M. luteus (Public Health England). They are seldom motile and are non-sporing. Micrococci can grow well in environments with little water or high salt concentrations, including sportswear that is made with synthetic fabrics. This is a test for aerobic (able to use oxygen) catalase-positive bacteria such as Staphylococcus and Micrococcus. On this Wikipedia the language links are at the top of the page across from the article title. Take a clean, scratch free glass slide. 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). 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). Micrococcus luteus was formerly known as Micrococcus lysodeikticus. 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. Date: FEB.11.2016 Micrococcus luteus was found gram-positive cocci, non-spore forming, non-haemolytic, non-motile aerobic or facultative anaerobes, arranged in pairs, irregular clusters and tetrads. Book a free counselling session. They are fairly ubiquitous in the environment, and are small (0.5 to 3.5 micrometers in diameter) and non-motile. Coagulase, which is an enzyme involved in the conversion of serum fibrinogen to fibrin, causes the clotting of plasma. Biochemical Tests in Microbiology Student Name Date 1 Lot Number(s) Record the lot numbers for each bacterial . This is termed alpha () hemolysis and results in a greenish color surrounding the colony. Micrococcus luteus can synthesize the iso-branched and anteiso-branched alkenes by the head-to-head condensation of fatty-acid thioesters. 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. Baird-Parker, A. c.: A classification of micrococci and staphylococci based on physiological and biochemical tests. 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.

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