This bacterium can withstand massive doses of UV radiation and it also has the capability to degrade certain pollutants such as petrol. The fluid thioglycallate test showed that the bacteria was an obligate aerobe because the growth was concentrated at the top of the tube in the pink region. Welcome to this Pearl of Laboratory Medicine on Basics of Differentiation of Gram-positive Cocci.. For the detection of oxidase enzyme, filter paper circular disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride in dimethyl sulfoxide are used. They are catalase-positive and usually aerobic with strictly respiratory metabolism. 2019). . 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. Care must be taken when using a sample of organism acquired from a sBAP since erythrocytes also produce catalase. 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. The micrococci produce tetrads consisting of 4 cocci clustered together. 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. They are found in soil, dust, water and air, and as part of the normal microbiota of skin. They grow on simple media and their colonies are usually pigmented. It is essential for differentiating catalase-positive Micrococcaceae from catalase-negative Streptococcaceae. In Wikipedia, The Free Encyclopedia. Source publication +9 Isolation and Identification of Potential Pathogenic Bacteria in Living Carp (Cyprinus carpio Linnaeus, 1758) Sold in. 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. . They occur in pairs, tetrads or clusters but not in chains. My goal in this experiment was to isolate, characterize and identify a bacterial colony that arose from a sample taken from my roommates nose. Bacteria Detail., The Editors of Encyclopdia Britannica. M. luteus present on the human skin can transform compounds present in sweat into compounds with an unpleasant odour. They can be found in boiling hot springs; they can be found in frigid waters in the artic. November 27, 2021 at 9:14 AM Hi sir, why Macrococcus and Micrococcus will not ferment . Micrococcus luteusare Gram-positive cocci mostly arranged in tetrads and larger than Staphylococcus. Only those with compromised immune systems are thought to be susceptible to an infection.DisinfectionM. The GC content of the DNA ranges from about 65 to 75 mol%. 1 Nevertheless they have been documented to be causative organisms in cases of bacteremia, endocarditis, ventriculitis, peritonitis, pneumonia, endophthalmitis, keratolysis and septic arthritis. This presentation will focus on the laboratory tests useful for the differentiation among the families as opposed to the more complicated differentiation and identification of the organisms within the different genera. 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. Coagulase, which is an enzyme involved in the conversion of serum fibrinogen to fibrin, causes the clotting of plasma. Hybridization studies show that there is no close genetic relationship between the species of Micrococcus bacteria. When looking at the genetic tests, most of the identified strains in the Korona test are Micrococcus luteus. //
The microdase test is a rapid method to differentiate Staphylococcus (-ve) from Micrococcus +ve) by detection of the enzyme oxidase. Most of these are mesophiles; some, like Micrococcus antarcticus which is found in Antarctica, are psychrophiles. 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. The EMB agar showed no growth or change in color, also indicating the microbe was gram positive and a non-fermenter. 1995; Wieser et al. The differentiation is based on the detection of the oxidase enzymes. 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 typical microscopic morphology of the Gram-positive cocci when using the Grams stain is represented in these three images. I chose to sample bacteria from inside my roommates nose. The bacterium also colonizes the human mouth, mucosae, oropharynx and upper respiratory tract. 91 988-660-2456 (Mon-Sun: 9am - 11pm IST), Want to read offline? They are catalase positive and often oxidase positive although this reaction may be weak (see Table 23.3 ). Enterobacter aerogenes fermented the sugars but turned to the amino acids. See answer (1) best answer. Figure 2. Date: FEB.11.2016
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). Examples of the colony morphology associated with each family is represented on this slide. Micrococcus Catalase Test: The catalase test facilitates the detection of the enzyme catalase in bacteria. 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 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.
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 has a G-C content of about 65-75 mol%. 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). 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. For the detection of oxidase enzyme, filter paper circular disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride in dimethyl sulfoxide are used. 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. Motility (Motile / Non-Motile) Non-Motile. 900 Seventh Street, NW Suite 400 The differentiation is based on the detection of oxidase enzyme. Klebsiella pneumoniae Micrococcus luteus Micrococcus roseus Proteus mirabilis Proteus vulgaris Pseudomonas aeruginosa Salmonella typhimurium Serratia marcescens Staphylococcus aureus Staphylococcus epidermidis Streptococcus . Micrococcus spp. Notice that beta-hemolysis results in a total lysis or clearing of the agar in the area of colony growth. 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. I am an associate professor in the Clinical Laboratory Science program at Wayne State University. It can be easily be mistaken for staphylococci, as they are very similar morphologically and physiologically (Wikipedia, Staphlyococcus Aureus). Abstract Micrococcus luteus IFO 3333 cells, both treated with chemical reagents and non-treated, were observed with a scanning electron microscope (SEM). CCTC (English)
Optimum growth temperature is 25-37 C. Bacillus megaterium fermented sugars but didn't grow in the anaerobic area of the butt. The laboratory assay is performed by mixing a sample of the bacterial colony with a drop(s) of hydrogen peroxide placed on a microscope slide. J Gen Microbiol 30(1963)409-427 . As its name suggests, mannitol salt agar (MSA) contains 1% mannitol (sugar), 7.5% salt, and agar as a solidifying agent. Under the microscope they are round cells. For example, Micrococcus varians is now known as Kocuria varians. Luteus is an obligate aerobe (medical. 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. Some of the Micrococcus are pigmented bacteria, for example, M. roseus produces reddish colonies and M. luteus produces yellow colonies. I used the PATRIC software to perform a metagenome binning and to assign a taxonomy to the bacteria. These discrepancies could be due to human error, unpure culture, or an old agar plate. Micrococcus varians Micrococcus luteus Staphylococcus saprophyticus Staphylococcus epidermidis Streptococcus pneumoniae Streptococcus mitis . On this Wikipedia the language links are at the top of the page across from the article title. Kaiju webserver metagenome binning analysis chart. Streptococcus pneumoniae and a group of streptococci referred to as viridans (green) streptococci are examples of bacteria producing alpha-hemolysis. 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.
Filter paper disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride (oxidase reagent) in dimethyl sulfoxide (DMSO) are used. Colony pigmentation varies considerably but is usually different shades of yellow or cream-white. With the advent of newer molecular techniques, genus and species confirmation is even faster and easier. In future works with this microbe, I probably would want to purify the culture more and redo the tests. 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). Several uncommon strains produce raised colonies with translucent, depressed centers. Alcaligenes faecalis Bacillus megaterium . 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 also not able to ferment glucose anaerobically (negative) Reply. Micrococcus luteus is a Gram-positive to Gram-variable, nonmotile, tetrad-arranging, pigmented, saprotrophic coccus bacterium in the family Micrococcaceae. 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). Micrococcus luteus, a commonly found member of the Micrococcaceae, produces round colonies which are convex (curving outward) with smooth, entire margins. They are catalase and oxidase positive whereas urease negative. 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. Intro: Microbes are everywhere, even in the most extreme environments and conditions. 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.
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. View Online Copy of Unknown ID Chart.xlsx from BIOL 250L at University of South Carolina. The optimum growth temperature is 25-37C. If acid is produced, the pH indicator will turn yellow. Micrococcus luteuswere discovered by Sir Alexander Fleming before he discovered penicillin in 1928. It has survived for at least 34,000 to 170,000 years, as assessed by 16S rRNA analysis, and possibly much longer. Streptococcus spp. 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. Micrococcus luteus is coagulase negative, bacitracin susceptible, and forms bright yellow colonies on nutrient agar. Staphylococcus spp. //
This suggests that some of the Micrococcus species on the basis of ribosomal RNA analysis eventually can be re-classified into other microbial 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. Label the slide with the name of the organism; Place 15 - 20 uL of the culture in the middle of the slide These include the slide or drop catalase test, the tube method, the semiquantitative catalase for the identification of Mycobacterium tuberculosis. Micrococci have been isolated from the human skin, animal and dairy products, and in beer. Further tests that I would do would be testing how much heat resistance it has, the density of a broth suspended sample using a dilution series, test for more antibiotic resistances, and how well it can grow in antibacterial mediums and mediums of different pH levels. SUMMARY: 1250 Gram-positive and catalase-positive cocci were isolated from bacon, pig and human skin and dust, and their morphology, physiology and biochemical characters examined. Note the bright yellow, non-diffusable colony pigment which is a defining characteristic of M. luteus. (2019, March 14). Enterococcus spp. Wikipedia contributors. I also did a fluid thioglycolate test to determine the bacterias oxygen class. They grow in circular, entire, convex, and creamy yellow-pigmented colonies with diameters of approximately 4 mm after 2-3 days at 37C. The streptococci and enterococci are categorized by expression of either beta, alpha, or gamma hemolysis on sBAP, depending on the genus/species. In Wikipedia, The Free Encyclopedia. The two unifying characteristics of these four families are their coccoid shape and the fact that they stain purple in the Grams method for visualizing bacteria microscopically. Micrococcus luteus biochemical test result. It shows that it is mostly Actinobacteria, with some firmicules ,and proteobacteria mixed in (Figure 2). This can occur due to the presence of a reduced number of proteins that can bind to penicillin. The species Micrococcus luteus (Schroeter 1872) Cohn 1872 (Approved Lists 1980) emend. It has also been isolated from foods such as milk and goats cheese. To identify our isolate after obtaining the pure culture, we performed many different tests. 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.