Reduction of O2 produces superoxide radicals and hydrogen peroxide, or the hydroxyl radical. This would be read as K/A. Most of the species produce carotenoid pigments. View Biochemical Tests Lab Report.docx from BIOL 240 at University of Alaska, Anchorage. Obtain a glucose fermentation tube. A positive test leads to the development of blue or purple-blue on the disc within two minutes. 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. 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. A very important test in the categorization of the staphylococci is the coagulase test. For the detection of oxidase enzyme, filter paper circular disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride in dimethyl sulfoxide are used. luteus is rarely found to be responsible for infections. They are fairly small as well, usually about a millimeter in diameter and of a normal height. Isolates of the M. luteus have been found to overproduce the riboflavin virus when they are grown on toxic organic pollutants like pyridine. Figure 2. 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. Micrococcus luteus (left) Alcaligenes faecalis (middle) Reduction of nitrate to nitrite to be used as a final electron acceptor/Nitrate reductase. 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. This microbe is coccus shaped and forms in tetrads. Because of their diversity, there are a variety of biochemical tests that are used by laboratories to identify the Gram-positive cocci. 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). . The first control consisted of plates of agar-agar to test sterility. Environmental Testing. Micrococcus spp. They are generally strict aerobes and can generally reduce nitrate. They are generally strict aerobes and these can generally reduce nitrate concentration. The oxygen class of the microbe, obligate aerobe, matches up with the predictions I had made about it because the bacteria was originally sourced in a nostril. Luteus is an obligate aerobe (medical. M. luteus is considered an opportunistic pathogen that can be responsible for some of the nosocomial infections. I used an API Strep test to determine more of the sugars the bacteria could ferment. Note the bright yellow, non-diffusable colony pigment which is a defining characteristic of M. luteus. The microdase test is a rapid method to differentiate Staphylococcus (-ve) from Micrococcus +ve) by detection of the enzyme oxidase. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Built with Enlightenment Theme and WordPress. M. luteus played an important part in Flemings discovery of Lysozyme which is the bodys natural antibiotic. The third image represents the colony morphology of many of the streptococci and enterococci. Micrococcus spp. It has multiple antibiotic resistance genes including dihydropteroate synthase, glycerophosphoryl diester phosphodiesterase, and SSU ribosomal proteins. Due to the thick structure of the bacterial cell wall, Gram-positive cocci retain the primary Grams stain, Crystal Violet. Micrococcus luteus characteristics possess unusual abilities to tolerate and to use very toxic organic molecules as carbon sources and it combines these activities with tolerance to metals. Members of the Staphylcocci can be differentiated based on production of the enzyme coagulase. The GC content of the DNA ranges from about 65 to 75 mol%. 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). A positive test leads to the development of blue or purple-blue on the disc within two minutes. They are also catalase-positive and often weakly oxidase-positive ( modified oxidase test positive). They grow in circular, entire, convex, and creamy yellow-pigmented colonies with diameters of approximately 4 mm after 2-3 days at 37C. It had 27,372 contigs in assembly. Bacillus megaterium fermented sugars but didn't grow in the anaerobic area of the butt. Micrococcus (pleural-micrococci) is free-living in the environment and also normal flora of the skin. The negative oxidase result conflicts with M. luteus (Public Health England). They also produce yellow or pink colonies when they are grown on the mannitol salt agar, micrococcus flavus, M. terreus, and M. yunnanensis. The genera Staphylococcus, Micrococcus and Sarcina were recognized. Micrococcus species are more sensitive to the Bacitracin while the staphylococci are resistant. M. luteus present on the human skin can transform compounds present in sweat into compounds with an unpleasant odour. 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. 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. About half of the Micrococcus luteus gram stain was found to carry plasmids of about one to 100MDa in size. 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. In Wikipedia, The Free Encyclopedia. Bharath. The catalase test facilitates the detection of the enzyme catalase in bacteria. Abstract: Gliotoxin, an epipolythiodioxopiperazine, is a fungal metabolite that causes genomic DNA degradation preferentially in certain blood cell types including T lymphocytes and macrophages. 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. There are around nine species that are recognized in the genus. The EMB plate is also selective for gram-negative bacteria which is probably why the bacteria didnt grow on it. If an organism is capable of fermenting the sugar glucose, then acidic byproducts are formed and the pH indicator turns yellow. 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. I grew my isolated in Tryptic Soy Broth (TSB) for a week to prepare for DNA extraction. Biochemical Tests in Microbiology Student Name Date 1 Lot Number(s) Record the lot numbers for each bacterial . Catalase test was the first biochemical test to be done . The oxidase test tests to see if the microbe contains cytochrome c oxidase. These include the slide or drop catalase test, the tube method, the semiquantitative catalase for the identification of Mycobacterium, M. luteus played an important part in Flemings discovery of, A rare case of prosthetic valve endocarditis is caused by Micrococcus luteus, it is described and compared with the few cases that are reported in the literature, as well as the clinical features, microbiological profile, therapy, and prognosis of common prosthetic valve endocarditis. 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). They are likely involved in the biodegradation of many other environmental pollutants or detoxification. Care must be taken when using a sample of organism acquired from a sBAP since erythrocytes also produce catalase. 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. Micrococci may be distinguished from staphylococci by a modified oxidase test as shown below-. 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. All pathogenic strains of S. aureus are coagulase positive whereas the nonpathogenic species (S. epidermidis for example) are coagulase negative. Evaluation of Antibacterial Properties of Iranian Medicinal-Plants against Micrococcus Luteus, Serratia Marcescens, Klebsiella Pneumoniae and Bordetella Bronchoseptica.. 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. As mentioned, the type of hemolytic reaction produced on sBAP is a major clue toward the identification of the genus. 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. Subscribe to our e-mail newsletter to receive updates. Beta-hemolysis is a defining characteristic of Staphylococcus aureus and a certain streptococci. AACC uses cookies to ensure the best website experience. 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. 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. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Built with Enlightenment Theme and WordPress. // Enterococcus spp. It has been associated with causing a variety of illnesses including septic arthritis, meningitis, endocarditis, chronic cutaneous infections in HIV-positive patients, and catheter infections. // This lines up with M. luteus resistances from the tests. The nasal cavity microbiota of healthy adults. When performing tests for physiological traits, the results were limited. 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. The catalase test tests to see if the microbe contains catalase. Growth can produce colonies of a certain size and consistency, as well as pigmentation. Oxidase (modified oxidase) test: Positive. Structure and PhysiologyThis bacteria is Gram-positive, spherical, and an obligate aerobe. Source publication +9 Isolation and Identification of Potential Pathogenic Bacteria in Living Carp (Cyprinus carpio Linnaeus, 1758) Sold in. After you have cultivated your organism on agar media, the next step is the microscopic examination. The coagulase test is performed by mixing a sample of organism with rabbit plasma. 2-9 In these reports micrococci were identified on the basis of their . 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. Many members of the genus have been reclassified into other genera. 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. 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. The colony forms as a yellow, shiny round blob. Finally I used different antibiotic disks to check for its resistance to antibiotics, using Gentamicin, Cefoperazone, Vancomycin, Tobramycin, Amikacin, Trimethoprim, Oxacillin, and Cefazdin. Wieser et al. They are positive for catalase and oxidase ( modified). It is an aerobic exopolysaccharide producing bacteria that may be found on the skin, mouth and sometimes in the throat of mammals 13,14. Make a tape label writing the color dot, your name, and the name of the media. All of these are described in the lab 6 handout and were kept in the incubator at 38 degrees Celsius. This technique is centered on the performance of the classic Grams stain. Date: FEB.11.2016 (negative). Micrococcus luteus is generally harmless but can become an opportunistic pathogen in immunocompromised people or those with indwelling catheters. This is designated as beta ()-hemolysis. (2019, April 4). Basics of Differentiation of Gram Positive Cocci, The Journal of Applied Laboratory Medicine, Challenges in Blood Group Alloantibody Detection, Clinical Applications of Complement Testing, Collecting Blood from Patients with Vascular Lines, Diagnosis of Syphilis Using the Reverse Algorithm, Liquid Chromatography LC Basics and Separation Techniques, Liquid Chromatography Separation Mechanisms, Optimal Reporting of Diagnostic Accuracy Studies, Pharmacogenetics for Drug Hypersensitivity Reactions, Sensitivity Specificity and Predictive Values in Diagnostic Testing, Transfusion Support in Hematopoietic Cell Transplant, Clinical Chemistry Guide to Scientific Writing, Commission on Accreditation in Clinical Chemistry.