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. U.S. 2022 American Association for Clinical Chemistry. 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. It is Gram positive, Coagulase positive, catalase and oxidase positive non-motile bacteria. Micrococcus luteuswere discovered by Sir Alexander Fleming before he discovered penicillin in 1928. The negative oxidase result conflicts with M. luteus (Public Health England). It is mostly Actinobacteria, but some Proteobacteria and Firmicules are in the sample as well. 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. When performing tests for physiological traits, the results were limited. 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. Perkins1, Sarah D., Jennie Mayfield2, and Victoria Fraser3 And. The optimum growth temperature is 25-37C. Micrococcus has a substantial cell wall in which it may comprise as much as 50% of the cell mass. They are normal inhabitants of the human body and may even be essential in keeping the balance among the various . Intro: Microbes are everywhere, even in the most extreme environments and conditions. In conclusion, some of my results were inconclusive and conflicting.
The sequencing of Micrococcus luteus was supported because of its major potential role in the case of bioremediation and its importance in the field of biotechnology. Biochemical 1- Catalase (+ve) 2- Coagulase (-ve) appear as agents of infection causing endocarditis. Micrococcus spp. Staphylococcus spp. The genus Micrococcus consists of Gram-positive spheres occurring in tetrads and in irregular clusters that are usually non-motile and non-spore-forming. 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. I chose to sample bacteria from inside my roommates nose. I extracted the DNA using the PowerSoil DNA kit (manufactured by Qiagen) following manufacturer instructions. Those are extremely toxic because they are powerful oxidizing agents and destroy cellular constituents very rapidly. Optimum growth temperature is 25-37 C. In Wikipedia, The Free Encyclopedia. Figure 2. Most of these are mesophiles; some, like Micrococcus antarcticus which is found in Antarctica, are psychrophiles.
Like MSA, this medium also contains the pH indicator, phenol red. 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. 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]. Genus: Micrococcus. 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.
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 luteus is another gram-positive coccus that also is catalase positive. M. luteus has a G-C content of about 65-75 mol%. 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. 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. When viewing the organism microscopically, the staining characteristics of the organism provide important information for identification. They are catalase positive and often oxidase positive although this reaction may be weak (see Table 23.3 ). These residential skin organisms are also fairly ubiquitous in the environment. Motility (Motile / Non-Motile) Non-Motile. Micrococcus luteus This Gram positive coccus is found in tetrads, irregular clusters, and cubical packets of eight. This is designated as beta ()-hemolysis. Members of the Staphylcocci can be differentiated based on production of the enzyme coagulase. The colony forms as a yellow, shiny round blob. Therefore I used this as my location to take my environmental sample from. [7], In 2003, it was proposed that one strain of Micrococcus luteus, ATCC 9341, be reclassified as Kocuria rhizophila. They contain cytochromes and are resistant to lysostaphin. Like all Staphylococci, S. saprophyticus is also clustering Gram-positive cocci, nonmotile, non-spore-forming, and . 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. 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. The nasal cavity microbiota of healthy adults. Enterococcus spp. This lines up with M. luteus resistances from the tests. . Three bacteria, E.coli, Staphylococcus epidermis, and Micrococcus luteus, have been grown on TSI or Triple sugar iron agar medium, which is a . This microbe forms large, round colonies. Micrococcus lutues are Gram positive cocci that are 0.5 to 3.5 m in diameter and arranged in tetrads or irregular clusters. 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. M. luteus is an obligate aerobe (Medical Laboratories). The colony morphology is the same as well, being round, shiny, and sort of flat (Medical Laboratories). The bubbling reaction is almost immediate and distinct in appearance. It has been isolated from human skin. Micrococcus luteus has been shown to survive in oligotrophic environments for extended periods of time. For example, M. luteus and M. lylae are 40-50% genetically different. Maximum production of pigments was observed at 35C, pH 9 and at 4% (W/V) NaCl concentration. Micrococcus luteus can synthesize the iso-branched and anteiso-branched alkenes by the head-to-head condensation of fatty-acid thioesters. They are generally strict aerobes and can generally reduce nitrate. Finally I used different antibiotic disks to check for its resistance to antibiotics, using Gentamicin, Cefoperazone, Vancomycin, Tobramycin, Amikacin, Trimethoprim, Oxacillin, and Cefazdin. It shows that it is mostly Actinobacteria, with some firmicules ,and proteobacteria mixed in (Figure 2). Micrococcus species, members of the family Micrococcaceae, are usually regarded as contaminants from skin and mucous membranes. My goal in this experiment was to isolate, characterize and identify a bacterial colony that arose from a sample taken from my roommates nose. 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. Abstract Micrococcus luteus IFO 3333 cells, both treated with chemical reagents and non-treated, were observed with a scanning electron microscope (SEM). Because of their diversity, there are a variety of biochemical tests that are used by laboratories to identify the Gram-positive cocci. In the final section of a study, it is essential to present important information, techniques, and variables. (negative). They are fairly ubiquitous in the environment, and are small (0.5 to 3.5 micrometers in diameter) and non-motile. 2- M. luteus 3- M.roseus Culture: - Strictly aerobic at 37C incubation (24 hr) - Grow on ordinary media Nutrient agar - Blood agar and on the Blood agar M. roseus (pink) M. luteus (white) M.varians (yellow) - On m annitol salt agar grow given r ise to rose or pink colonies except M. roseus. 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. Filter paper disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride (oxidase reagent) in dimethyl sulfoxide (DMSO) are used. This bacterium can also be transmitted to others due to poor hand-washing practices. About half of the Micrococcus luteus gram stain was found to carry plasmids of about one to 100MDa in size. Discussion: When looking at all of the results for my isolate, they are not all consistent with Micrococcus luteus. Streptococci and enterococci are observed to produce pairs and chains of cocci of varying length. 2. Micrococci are usually not pathogenic. Ans: Micrococci, like many other representatives of the Actinobacteria, can be catabolically versatile, with the ability to utilize a wide range of unusual substrates, such as herbicides, pyridine, chlorinated biphenyls, and oil. Some Micrococcus are pigmented bacteria; for example, M. luteus produces yellow colonies and M. roseus produces redish colonies. The catalase test tests to see if the microbe contains catalase. Biochemical Test Chart (You will not fill in every blank in this chart.) On this Wikipedia the language links are at the top of the page across from the article title. //
Although the Micrococcus rarely causes infections or problems in the body, with the compromised immune systems, it has been known to get certain skin infections that are caused by Micrococcus luteus. I used the PATRIC software to perform a metagenome binning and to assign a taxonomy to the bacteria. It had 27,372 contigs in assembly. 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. Micrococcus luteus was formerly known as Micrococcus lysodeikticus.
Colonies typically have a lemon-yellow pigment. //
CATALASE TEST: Catalases are enzymes that convert hydrogen peroxide (H2O2) into water and oxygen gas. Micrococcus luteus in tetrads arrangement. Micrococcus varians Micrococcus luteus Staphylococcus saprophyticus Staphylococcus epidermidis Streptococcus pneumoniae Streptococcus mitis are gram-positive, oxidase-positive, and strictly they are aerobic cocci that are belonging to the family Micrococcaceae. The results of this analysis are shown in table 1. The API 20 Strep test I used came up with no conclusive results. 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. Kaiju webserver metagenome binning analysis chart. The categorization of bacteria in the clinical laboratory is based on the reactivity of the organism when stained by the Grams staining reagents. Another test I did to identify my isolate was DNA analysis, described in lab handouts 5 and 7. 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. 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. Whereas the M. variant has a G-C content of about 66-72mol%. At U.S. Micro Solutions, our microbiology laboratory is a licensed, accredited source for thorough and accurate environmental testing . Annals of Allergy, Asthma and Immunology 122(1):17-24. luteus is capable of surviving in environments They are catalase-positive and usually aerobic with strictly respiratory metabolism. This would be read A/NC. They have a respiratory metabolism, often producing little or no acid from carbohydrates, and are usually halotolerant, growing in 5% NaCl. 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. 2014). 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 . Institute for Quality and Efficiency in Health Care. Though today the immuno-compromised patients take the risk of the infection that has grown. The catalase test facilitates the detection of the enzyme catalase in bacteria.
Characteristics. The coagulase test is performed by mixing a sample of organism with rabbit plasma. [1] It is urease and catalase positive. The genera Staphylococcus, Micrococcus and Sarcina were recognized. Though today the immuno-compromised patients take the risk of the infection that has grown. 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]. They are usually normal flora but can be opportunistic pathogens in certain immunocompromised patients. For the detection of oxidase enzyme, filter paper circular disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride in dimethyl sulfoxide are used. We will discuss this shortly. Mannitol salt agar (MSA) is a selective, differential, and indicator medium used to isolate and identify Staphylococcus aureus from the clinical specimen. The microbiome of the nose. This bacterium is often arranged in the form of circular tetrads and it forms bright yellow colonies on nutrient agar. With the advent of newer molecular techniques, genus and species confirmation is even faster and easier. 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. Oral microbial flora of reptiles includes bacteria from Proteus, Porphyromonas, Micrococcus, Salmonella and Staphylococcus genera 5,8,15.