They are indole negative, oxidase-positive, catalase-positive, and citrate negative. 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. luteus is rarely found to be responsible for infections. The gram stain of this microbe showed that it is gram positive because it stained purple. They also produce yellow or pink colonies when they are grown on the mannitol salt agar, micrococcus flavus, M. terreus, and M. yunnanensis. The species Micrococcus luteus (Schroeter 1872) Cohn 1872 (Approved Lists 1980) emend. 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 catalase test facilitates the detection of the enzyme catalase in bacteria. (2019, March 14). The results of these tests provide a biochemical profile, or "fingerprint," that can be used to classify or even identify the bacterial species. Maximum production of pigments was observed at 35C, pH 9 and at 4% (W/V) NaCl concentration.
The oxidase test results suggest that the microbe does not contain oxidase, despite what the metagenome binning test showed. 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. AACC uses cookies to ensure the best website experience. The tetrads of the micrococci, the grape like clusters of the staphylococci, and the pairs and/or chains of the streptococci are shown. 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). Discussion: When looking at all of the results for my isolate, they are not all consistent with Micrococcus luteus. 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. Ans: Although it is a harmless saprophyte, Micrococcus luteus can act as an opportunistic pathogen. They are found in many other places in the, M. luteus has one of the smallest genomes of all the bacteria. Micrococcus luteus biochemical test result. A very important test in the categorization of the staphylococci is the coagulase test. Coagulase Results: Micrococci can grow well in environments with little water or high salt concentrations, including sportswear that is made with synthetic fabrics. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Built with Enlightenment Theme and WordPress. When looking at the genetic tests, most of the identified strains in the Korona test are Micrococcus luteus. AACC.org
If the agar plate is held up to a light source, you can sometimes see through the agar, as is pictured on the left. This suggests that some of the Micrococcus species on the basis of ribosomal RNA analysis eventually can be re-classified into other microbial genera. Klebsiella pneumoniae Micrococcus luteus Micrococcus roseus Proteus mirabilis Proteus vulgaris Pseudomonas aeruginosa Salmonella typhimurium Serratia marcescens Staphylococcus aureus Staphylococcus epidermidis Streptococcus . The colonies are a pale, translucent yellow, and are shiny when looked at in the light. Is Micrococcus luteus indole positive? Micrococcus luteus has been shown to survive in oligotrophic environments for extended periods of time. Continuing without changing cookie settings assumes you consent to our use of cookies on this device. 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 luteuswere discovered by Sir Alexander Fleming before he discovered penicillin in 1928. The staphylococci are characterized by the formation of clusters of many cocci. Staphylococcus spp. 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. 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. It may appear in irregular clusters, groups of four or eight. Micrococcus luteus was formerly known as Micrococcus lysodeikticus. [2] It resists antibiotic treatment by slowing of major metabolic processes and induction of unique genes[citation needed]. Examples of the colony morphology associated with each family is represented on this slide. The typical microscopic morphology of the Gram-positive cocci when using the Grams stain is represented in these three images. 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). 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. The categorization of bacteria in the clinical laboratory is based on the reactivity of the organism when stained by the Grams staining reagents. They can even survive in conditions that have very little of even no oxygen, using glycolysis and alternative electron acceptors to create ATP. 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. As mentioned, the type of hemolytic reaction produced on sBAP is a major clue toward the identification of the genus. It is a gram positive, coccus shaped microbe, and contains catalase.
all 3 tests done w/SIM deeps just add Kovac's reagent for Indole test Alcaligenes faecalis (left) - . From: Infectious Diseases (Third Edition), 2010 View all Topics About this page I chose to sample bacteria from inside my roommates nose. 2002). Catalase, if present, will break down the hydrogen peroxide to water and oxygen. Staphylococcus spp. Gram Staining. This is termed alpha () hemolysis and results in a greenish color surrounding the colony. They are normal inhabitants of the human body and may even be essential in keeping the balance among the various . View Biochemical Tests Lab Report.docx from BIOL 240 at University of Alaska, Anchorage. The reactions of the four isolates indicated that they belonged to the species M. Zuteus (Kocur & Martinec, 1972). 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. This lines up with M. luteus resistances from the tests. This bacterium can withstand massive doses of UV radiation and it also has the capability to degrade certain pollutants such as petrol. An obligate aerobe, M. luteus is found in soil, dust, water and air, and as part of the normal microbiota of the mammalian skin. Streptococci and enterococci are observed to produce pairs and chains of cocci of varying length.
Whereas the M. variant has a G-C content of about 66-72mol%. It has been isolated from human skin. 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 Kaiju webserver metagenome binning analysis chart. It has survived for at least 34,000 to 170,000 years, as assessed by 16S rRNA analysis, and possibly much longer. Though today the immuno-compromised patients take the risk of the infection that has grown. (negative). The pathogen, Staphylococcus aureus, is notably coagulase-positive while most other members of the family are coagulase-negative. Perkins1, Sarah D., Jennie Mayfield2, and Victoria Fraser3 And. M. luteus has the capability to show dormancy without the formation of spores. Defining characteristics of Micrococcus are the ability to aerobically produce acid from glucose glycerol, aesculin hydrolysis, arginine dihydrolase, major pigment production, motility, and conversion of nitrate to nitrite. Micrococci can often carry plasmids that provide the organism with useful traits. 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. Obtain a glucose fermentation tube. Bassis CM, AL Tang, VB Young, and MA Pynnonen (2014). 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. Coagulase, which is an enzyme involved in the conversion of serum fibrinogen to fibrin, causes the clotting of plasma. CCTC (English)
This technique is centered on the performance of the classic Grams stain. The microbiome of the nasal cavity can also change in response to environmental factors such as geographic location, and hygiene (Rawis et al. 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 species are strictly aerobic Gram-positive cocci arranged in tetrads or irregular clusters, and cells range from 0.5 to 3 m in diameter. Similar to the situation in the prosthetic valve endocarditis that is caused by more aggressive and highly resistant bacteria. U.S. 2022 American Association for Clinical Chemistry. With this almost universal range of survivable living conditions that microbes can live in (particularly bacteria), it would be reasonable to assume that there would be at least one variety living in such a nice, wet, and aerated place as my shower drain. As its name suggests, mannitol salt agar (MSA) contains 1% mannitol (sugar), 7.5% salt, and agar as a solidifying agent. Bacteria Detail., The Editors of Encyclopdia Britannica. 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. Streptococcus pneumoniae and a group of streptococci referred to as viridans (green) streptococci are examples of bacteria producing alpha-hemolysis. CATALASE TEST: Catalases are enzymes that convert hydrogen peroxide (H2O2) into water and oxygen gas. 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. 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.