micrococcus luteus biochemical tests

I extracted the DNA using the PowerSoil DNA kit (manufactured by Qiagen) following manufacturer instructions. Biochemical Pr Organism Enterococcus faecalis Lactococcus lactis Micrococcus luteus Staphylococcus 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. They are considered as normal comensal of human skin and upper respiratory tract. I suspect that the API 20E test strip results were negated by having used an inactive colony, as the fluid thyoglycate test failed as well. AACC.org 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. About half of the Micrococcus luteus gram stain was found to carry plasmids of about one to 100MDa in size. (2010) What are microbes? Growth or weak growth is observed at 45C, at pH 10, and in the presence of 10% sodium chloride (NaCl). Where the M. luteus can cause severe skin infections and is sometimes clinically mistaken for Staphylococcus aureus. Annals of Allergy, Asthma and Immunology 122(1):17-24. M. luteus is part of the normal flora of the human skin.Transmission and DiseaseM. The bacterium also colonizes the mouth, mucosae, oropharynx, and upper respiratory tract. // For the second control, 100 L of water sample dilutions were plated on agar-agar. The genus Micrococcus consists of Gram-positive spheres occurring in tetrads and in irregular clusters that are usually non-motile and non-spore-forming. Make a tape label writing the color dot, your name, and the name of the media. Thank you for joining me, Karen Krisher, on this Pearl of Laboratory Medicine on Basics of Differentiation of Gram-positive Cocci.. Intermediates or end products of these varied metabolic activities can be detected by performing biochemical assays on a bacterial culture. The differentiation is based on the detection of the oxidase enzymes. Download Scientific Diagram from www.researchgate.net. Staphylococci were distinguished by their ability to form acid from glucose anaerobically and sarcinas by the formation of cubical packets. This lines up with M. luteus resistances from the tests. 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. For example, M. luteus and M. lylae are 40-50% genetically different. The configurations are the result of the plane of cellular division exhibited by the organism. Micrococcus luteus in tetrads arrangement. It is difficult to differentiate Kocuria from Micrococcus with conventional biochemical methods; therefore, these organisms are often reported together as Micrococcus/Kocuria species. If acid is produced, the pH indicator will turn yellow. 2-9 In these reports micrococci were identified on the basis of their . Your email address will not be published. Care must be taken when using a sample of organism acquired from a sBAP since erythrocytes also produce catalase. Micrococcus luteus has been shown to survive in oligotrophic environments for extended periods of time. 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. J Gen Microbiol 30(1963)409-427 . 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. M. luteus oxidizes carbohydrates to CO2 and water, and it does not produce acid from glucose as well as it does not make arginine dihydrolase or b-galactosidase. Micrococcus spp. Production of bubbles indicates a positive reaction. It shows that it is mostly Actinobacteria, with some firmicules ,and proteobacteria mixed in (Figure 2). Enter the email address you signed up with and we'll email you a reset link. They have a respiratory metabolism, often producing little or no acid from carbohydrates, and are usually halotolerant, growing in 5% NaCl. Motility (Motile / Non-Motile) Non-Motile. What are the Diseases that are Caused By Micrococcus? Micrococcus luteuswere discovered by Sir Alexander Fleming before he discovered penicillin in 1928. The optimum growth temperature is 25-37C. Whereas the M. variant has a G-C content of about 66-72mol%. So far there are two genome sequences that have been done. The nasal cavity microbiome primarily consists of the phyla Actinobacteria, Firmicutes and Proteobacteria (Bassis et al. Other articles where Micrococcus luteus is discussed: Micrococcus: found in milk, such as M. luteus, M. varians, and M. freudenreichii, are sometimes referred to as milk micrococci and can result in spoilage of milk products. Cells are catalase positive, oxidase positive, and exhibit strictly aerobic metabolism. 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. M. luteus can also cause septic shocks in immuno-compromised people. 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. Due to the thick structure of the bacterial cell wall, Gram-positive cocci retain the primary Grams stain, Crystal Violet. 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. M. luteus is an obligate aerobe (Medical Laboratories). Perkins1, Sarah D., Jennie Mayfield2, and Victoria Fraser3 And. The colony forms as a yellow, shiny round blob. Micrococcus spp. They are also catalase-positive and often weakly oxidase-positive ( modified oxidase test positive). Whereas the M. variant has a G-C content of about 66-72mol%. Catalase, if present, will break down the hydrogen peroxide to water and oxygen. [8], Norwegian researchers in 2013 found a M. luteus strain that synthesizes a pigment that absorbs wavelengths of light from 350 to 475 nanometers. This matches up with the PATRIC metagenome binning which also showed some impurities (Figure 1). For the detection of oxidase enzyme, filter paper circular disks impregnated with tetramethyl-p-phenylenediamine dihydrochloride in dimethyl sulfoxide are used. "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. ? Those are extremely toxic because they are powerful oxidizing agents and destroy cellular constituents very rapidly. 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. 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. As the microbe is gram positive this means that it has a large peptidoglycan layer and lacks a lipopolysaccharide layer. Members of the Staphylcocci can be differentiated based on production of the enzyme coagulase. Micrococcus Public Health Agency of Canada., Public Health England. 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. Streptococcus pneumoniae and a group of streptococci referred to as viridans (green) streptococci are examples of bacteria producing alpha-hemolysis. The micrococci produce tetrads consisting of 4 cocci clustered together. The organism itself is susceptible to almost all drugs, with a few strains being resistant to nitrofurantoin, macrolides and lincomycin (Public Health Canada). The conflicting results of the metagenome binning and the catalase test influenced this mistake. The tests that did not agree were most likely from not having an active colony used in the experiment, such as the oxidase test being negative or the API 20 E test strip showing that the isolate did not reduce nitrate, which it does, referencing Medical Laboratories. 570 . Staphylococcus aureus. U.S. 2022 American Association for Clinical Chemistry. This is a test commonly used when trying to identify Gram-negative enteric bacteria, all of which are glucose fermenters but only some of which produce gas. Coagulase Results: The antibiotic resistance test showed only minor resistance to the antibiotic Oxacillin, which is likely due to a chance inheritance in the population or complete chance because of the weak strength. Like MSA, this medium also contains the pH indicator, phenol red. Microbiome 2(27). M. luteus causes odours in humans when breaking down the components of sweat. Characteristics. Ans: Although it is a harmless saprophyte, Micrococcus luteus can act as an opportunistic pathogen. Micrococcaceae. Recent reports, however, confirm that micrococci may be associated with human infections, particularly in immunosuppressed patients. The colony took 16 days to be purified. An obligate aerobe, M. luteus is found in soil, dust, water and air, and as part of the normal microbiota of the mammalian skin. The differentiation is based on the detection of oxidase enzyme. They are generally strict aerobes and these can generally reduce nitrate concentration. The staphylococci are characterized by the formation of clusters of many cocci. Welcome to this Pearl of Laboratory Medicine on Basics of Differentiation of Gram-positive Cocci.. I used the Kirby-Bauer, or disk diffusion test to test for this, described in lab handout 9. The API 20 Strep test I used came up with no conclusive results. Complete lysis of the erythrocytes in the vicinity of the growing colony. Micrococcus luteus Grown on BrainHeart Infusion Agar, Klebsiella characteristics on MacConkey Agar, Clinical Case Leukocyte Vacoulation Bacterial Infection, Segmented neutrophilic granulocyte during degradation, DIC (Disseminated intravascular coagulation), Creatinine Phosphate Kinase (CPK) and CK-MB Overview. Micrococcus spp. 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. The microdase test is a rapid method to differentiate Staphylococcus (-ve) from Micrococcus +ve) by detection of the enzyme oxidase. The confidence on that reading is decently confident, evidenced by the blue coloring. Streptococci and enterococci are observed to produce pairs and chains of cocci of varying length. luteus is capable of surviving in environments If I were to continue researching this isolate, I would redo the API 20 E test strip with a fresh, active culture to ensure that it can reduce nitrate, and also the oxidase test to ensure that it does have cytochrome c oxidase present, which it should according to Public Health England. PUGVIEW FETCH ERROR: 403 Forbidden National Center for Biotechnology Information 8600 Rockville Pike, Bethesda, MD, 20894 USA Contact Policies FOIA HHS Vulnerability Disclosure National Library of Medicine National Institutes of Health In the final section of a study, it is essential to present important information, techniques, and variables. The genera Staphylococcus, Micrococcus and Sarcina were recognized. It shows that the sample contains bacteria from the Terrabacteria group. 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. The mammalian skin that has M. luteus strain is also highly sensitive to the beta-lactam antibiotics. When looking at the antibiotic test results, the isolate is resistant to none of the applied antibiotics, and is only lightly to intermediately resistant to oxacillin. The bacterium also colonizes the human mouth, mucosae, oropharynx and upper respiratory tract. On this Wikipedia the language links are at the top of the page across from the article title. They are found in many other places in the, M. luteus has one of the smallest genomes of all the bacteria. Three bacteria, E.coli, Staphylococcus epidermis, and Micrococcus luteus, have been grown on TSI or Triple sugar iron agar medium, which is a . Some of the species of Micrococcus, such as M. luteus which is yellow in colour, and M. roseus which is red. Notice that beta-hemolysis results in a total lysis or clearing of the agar in the area of colony growth. They usually can occur in the irregular clusters, tetrads, and in pairs, where the individual cells are about one to 1.8 mm in diameter and these are usually non-motile and non-spore-forming in nature. I used an API Strep test to determine more of the sugars the bacteria could ferment. Discussion: When looking at all of the results for my isolate, they are not all consistent with Micrococcus luteus. The first control consisted of plates of agar-agar to test sterility. The metabolic pathways required for biomass production in silico were determined based on earlier models of actinobacteria. nishinomiyaensis and Micrococcus luteus. Micrococci may be distinguished from staphylococci by a modified oxidase test as shown below-. A summary table is included which lists the results of the identification criteria discussed in the tutorial. Beta-hemolysis is a defining characteristic of Staphylococcus aureus and a certain streptococci. // At U.S. Micro Solutions, our microbiology laboratory is a licensed, accredited source for thorough and accurate environmental testing . 1995; Wieser et al. They are catalase positive and often oxidase positive although this reaction may be weak (see Table 23.3 ). They also produce yellow or pink colonies when they are grown on the mannitol salt agar, micrococcus flavus, M. terreus, and M. yunnanensis. Each genus lends itself to a separate tutorial. Klebsiella pneumoniae Micrococcus luteus Micrococcus roseus Proteus mirabilis Proteus vulgaris Pseudomonas aeruginosa Salmonella typhimurium Serratia marcescens Staphylococcus aureus Staphylococcus epidermidis Streptococcus . The name of the genus is also called " Germanized " is written as Micrococcus. 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. Each family of Gram-positive cocci has its own unique configuration. Micrococcus luteus uses the amino acids and does not grow in the butt of the slant. Although it's tempting to write a summary of the entire study but it . Bharath. When performing tests for physiological traits, the results were limited. M. luteus has one of the smallest genomes of actinobacteria with a circular chromosome of 2,501,097 base pairs and a GC content of 73%. 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. are gram-positive, oxidase-positive, and strictly they are aerobic cocci that are belonging to the family Micrococcaceae. These results might not be trustworthy. They are generally strict aerobes and can generally reduce nitrate. 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. They are fairly ubiquitous in the environment, and are small (0.5 to 3.5 micrometers in diameter) and non-motile. Take a clean, scratch free glass slide. 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 catalase test facilitates the detection of the enzyme catalase in bacteria. It is an opportunistic pathogen, only pathogenic enough to cause disease in weakened immune systems (Medical Laboratories). 2. Micrococcus lutues are Gram positive cocci that are 0.5 to 3.5 m in diameter and arranged in tetrads or irregular clusters. Following incubation at 37oC, if the plasma forms a clot, the organism is coagulase positive. The kaiju metagenome binning shows that the microbe sample is not completely pure (Figure 2). Biochemical Tests in Microbiology Student Name Date 1 Lot Number(s) Record the lot numbers for each bacterial . Similar to the situation in the prosthetic valve endocarditis that is caused by more aggressive and highly resistant bacteria. Table 1: Graph from Korona showing the percent reads of each organism, and to which taxonomic level. download full PDF here, Some of the species of Micrococcus, such as M. luteus which is yellow in colour, and M. roseus which is red. Micrococcus luteus biochemical test result. 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. Institute for Quality and Efficiency in Health Care. // Know more about our courses. 2002). Pearls of Laboratory Medicine The positive catalase result lines up with M. luteus (Public Health England). Environmental Testing. Sarah D. Perkins., Government of Canada, Public Health Agency of Canada. The results of these tests provide a biochemical profile, or "fingerprint," that can be used to classify or even identify the bacterial species. It is reported here that gliotoxin selectively spares a unique class of haemopoietic stem cell that forms large (HPP) colonies in the presence of mixtures of MCSF and IL3. Typical colonies are often described as gray to white, moist or glistening. Micrococci can often carry plasmids that provide the organism with useful traits. For example, M. luteus and M. lylae are 40-50% genetically different. 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. The bubbling reaction is almost immediate and distinct in appearance. I think based on all this information, that my microbe is in fact micrococcus luteus as suggested by the PATRIC metagenome binning test, and the krona (Figure 1). Basics of Differentiation of Gram Positive Cocci, Author: Karen Krisher Micrococcus has a substantial cell wall in which it may comprise as much as 50% of the cell mass. Gamma or no hemolysis results in no characteristic display in the vicinity of the colony. Once the culture was deemed pure enough, I inoculated a slant tube. The microbiome of the nasal cavity can also change in response to environmental factors such as geographic location, and hygiene (Rawis et al. These discrepancies could be due to human error, unpure culture, or an old agar plate. 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. Unlike other actinobacteria, M. luteus expresses only one resuscitation-promoting factor that is required for the emergence from dormancy and has few other dormancy-related proteins. All pathogenic strains of S. aureus are coagulase positive whereas the nonpathogenic species (S. epidermidis for example) are coagulase negative. Examples of the colony morphology associated with each family is represented on this slide. The coagulase test is performed by mixing a sample of organism with rabbit plasma. In contrast to staphylococci, usually, penicillin is sensitive. As mentioned, the type of hemolytic reaction produced on sBAP is a major clue toward the identification of the genus. I then transferred the pure culture into a TSB slant to preserve it, keeping it at around 3 degrees Celsius in the lab refrigerator. luteus is rarely found to be responsible for infections. Because of their diversity, there are a variety of biochemical tests that are used by laboratories to identify the Gram-positive cocci. Hybridization studies show that there is no close genetic relationship between the species of Micrococcus bacteria.