{"id":598,"date":"2022-01-03T14:27:00","date_gmt":"2022-01-03T08:42:00","guid":{"rendered":"https:\/\/microbiologypractical.com\/?p=203"},"modified":"2023-03-03T21:33:27","modified_gmt":"2023-03-03T15:48:27","slug":"4-methylumbelliferyl-%ce%b2-d-glucuronide-mug-test","status":"publish","type":"post","link":"https:\/\/microbenotes.com\/4-methylumbelliferyl-%ce%b2-d-glucuronide-mug-test\/","title":{"rendered":"MUG Test- Objective, Principle,\u00a0Procedure,\u00a0Result, Limitations"},"content":{"rendered":"\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_65 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title \" >Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #0a0a0a;color:#0a0a0a\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #0a0a0a;color:#0a0a0a\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/microbenotes.com\/4-methylumbelliferyl-%ce%b2-d-glucuronide-mug-test\/#objective-of-mug-test\" title=\"Objective of MUG Test\">Objective of MUG Test<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/microbenotes.com\/4-methylumbelliferyl-%ce%b2-d-glucuronide-mug-test\/#principle-of-mug-test\" title=\"Principle&nbsp;of MUG Test\">Principle&nbsp;of MUG Test<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/microbenotes.com\/4-methylumbelliferyl-%ce%b2-d-glucuronide-mug-test\/#procedure-of-mug-test\" title=\"Procedure&nbsp;of MUG Test\">Procedure&nbsp;of MUG Test<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/microbenotes.com\/4-methylumbelliferyl-%ce%b2-d-glucuronide-mug-test\/#direct-disk-test\" title=\"Direct disk test\">Direct disk test<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/microbenotes.com\/4-methylumbelliferyl-%ce%b2-d-glucuronide-mug-test\/#tube-test\" title=\"Tube test \">Tube test <\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/microbenotes.com\/4-methylumbelliferyl-%ce%b2-d-glucuronide-mug-test\/#result-interpretation-of-mug-test\" title=\"Result Interpretation of MUG Test\">Result Interpretation of MUG Test<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/microbenotes.com\/4-methylumbelliferyl-%ce%b2-d-glucuronide-mug-test\/#limitations-of-mug-test\" title=\"Limitations&nbsp;of MUG Test\">Limitations&nbsp;of MUG Test<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/microbenotes.com\/4-methylumbelliferyl-%ce%b2-d-glucuronide-mug-test\/#quality-control-of-mug-test\" title=\"Quality Control&nbsp;of MUG Test\">Quality Control&nbsp;of MUG Test<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/microbenotes.com\/4-methylumbelliferyl-%ce%b2-d-glucuronide-mug-test\/#references\" title=\"References \">References <\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"objective-of-mug-test\"><\/span><span style=\"color: #000000;\"><strong>Objective of MUG Test<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><span style=\"color: #000000;\">To identify various genera of <a href=\"https:\/\/microbenotes.com\/enterobacteriaceae-cultural-characteristics\/\" target=\"_blank\" rel=\"noreferrer noopener\">Enterobacteriaceae<\/a> and verotoxin-producing <em>Escherichia coli.<\/em><\/span><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"principle-of-mug-test\"><\/span><span style=\"color: #000000;\"><strong>Principle&nbsp;of MUG Test<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>MUG is an acronym for <strong>4-methylumbelliferyl-beta-D-glucuronide<\/strong>, a fluorogenic substrate of \u03b2-glucuronidase. <span style=\"color: #000000;\">\u03b2-D-Glucuronidase is an enzyme produced by most strains of <em>E. coli<\/em> and other Enterobacteriaceae&nbsp;which hydrolyzes \u03b2-d-glucopyranosid-uronic derivatives to aglycons and d-glucuronic acid. The substrate 4-methylumbelliferyl-beta-D-glucuronide is impregnated in the disc. The organism capable of producing the \u03b2- D- Glucuronidase enzyme has the ability to cleave the substrate 4- Methylumbelliferyl- \u03b2- D- Glucuronide and thereby produces a &nbsp;fluorescent moiety 4-methylumbelliferyl (4-MU). The end product of hydrolysis, 4-methylumbelliferyl (4-MU), fluoresces blue under long-wavelength<\/span> ultraviolet light. However, verotoxin-producing<span style=\"color: #000000;\"> strains of <em>E. coli <\/em>do not produce MUG, and a negative test result may indicate the presence of a clinically important strain. 4-MU fluorescence is pH-dependent with excitation maxima of 320 and 360 nm at low (1.97-6.72) and high (7.12-10.3) pH, respectively.<\/span><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"procedure-of-mug-test\"><\/span><span style=\"color: #000000;\"><strong>Procedure&nbsp;of MUG Test<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"direct-disk-test\"><\/span><span style=\"color: #000000;\"><strong>Direct disk test<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ol>\n<li><span style=\"color: #000000;\">Place a MUG disk in an empty sterile petri dish and add a drop of demineralized water.<\/span><\/li>\n\n\n\n<li><span style=\"color: #000000;\">Smear 2-3 isolated colonies from 18-24 hour old culture on the disk.<\/span><\/li>\n\n\n\n<li><span style=\"color: #000000;\">Place a piece of filter paper saturated with water in the lid of the petri dish to provide humid environment.<\/span><\/li>\n\n\n\n<li><span style=\"color: #000000;\">Incubate aerobically at 35\u00b0-37\u00b0C for up to 30 minutes.<\/span><\/li>\n\n\n\n<li><span style=\"color: #000000;\">Following incubation, examine the disk for fluorescence using longwave ultraviolet light (360nm) in a darkened room.<\/span><\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"tube-test\"><\/span><span style=\"color: #000000;\"><strong>Tube test <\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ol>\n<li><span style=\"color: #000000;\">Add 0.25ml of demineralized water to a clean glass tube.<\/span><\/li>\n\n\n\n<li><span style=\"color: #000000;\">Make a heavy suspension with 3- 4 colonies of test isolate in the tube.<\/span><\/li>\n\n\n\n<li><span style=\"color: #000000;\">Using forcep, place a MUG disk in the tube and shake vigorously to ensure adequate elution of substrate in the surrounding liquid.<\/span><\/li>\n\n\n\n<li><span style=\"color: #000000;\">Incubate aerobically at 35\u00b0-37\u00b0C for up to 1 hour.<\/span><\/li>\n\n\n\n<li><span style=\"color: #000000;\">Following incubation, examine the disk for fluorescence using longwave ultraviolet light (360nm) in a darkened room.<\/span><\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"result-interpretation-of-mug-test\"><\/span><span style=\"color: #000000;\"><strong>Result Interpretation of MUG Test<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><img decoding=\"async\" src=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2018\/06\/4-Methylumbelliferyl-\u03b2-D-Glucuronide-MUG-Test.png\" alt=\"4-Methylumbelliferyl-\u03b2-D-Glucuronide (MUG) Test\" class=\"wp-image-204\"\/><figcaption class=\"wp-element-caption\">Figure: MUG Test. Photo Credit: <a href=\"https:\/\/xiaohuilau.com\/2015\/09\/lets-take-a-mug-shot\/\" target=\"_blank\" data-type=\"URL\" data-id=\"https:\/\/xiaohuilau.com\/2015\/09\/lets-take-a-mug-shot\/\" rel=\"noreferrer noopener\">Xiao Hui Lau<\/a>.<\/figcaption><\/figure><\/div>\n\n\n<p><span style=\"color: #000000;\"><strong>Positive test:<\/strong>&nbsp; blue fluorescence<\/span><\/p>\n\n\n\n<p><span style=\"color: #000000;\"><strong>Negative test: <\/strong>no fluorescence<\/span><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"limitations-of-mug-test\"><\/span><span style=\"color: #000000;\"><strong>Limitations&nbsp;of MUG Test<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ol>\n<li><span style=\"color: #000000;\">This test is only part of the overall scheme for identification of <em>E. coli<\/em>. Further biochemical and serological testing is required for definitive identification.<\/span><\/li>\n\n\n\n<li><span style=\"color: #000000;\">Most strains of <em> E. coli<\/em> 0157:H7 are MUG negative. The use of an <em>E. coli<\/em> 0157:H7 latex agglutination test in conjunction with the MUG test is recommended for rapid identification of isolates during outbreaks.<\/span><\/li>\n\n\n\n<li><span style=\"color: #000000;\">Some strains of <em>Shigella<\/em> are MUG positive. Serological testing may be required to differentiate <em>Shigella<\/em> and <em> E. coli<\/em>.<\/span><\/li>\n\n\n\n<li><span style=\"color: #000000;\">False negative reactions may be reported when test colonies isolated from medias containing dyes (EMB, MAC) are used and hence it may make the interpretation difficult.<\/span><\/li>\n\n\n\n<li><span style=\"color: #000000;\">Organisms other than<em> E. coli<\/em> like <em>Salmonella, Shigella, Staphylococcus, Streptococcus<\/em> possess the enzyme \u03b2-Glucuronidase and are MUG positive. Testing only lactose positive, gram negative rods for \u03b2 \u2013 Glucuronidase activity helps preclude misidentification of other organisms as <em>E. coli<\/em>.<\/span><\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"quality-control-of-mug-test\"><\/span><span style=\"color: #000000;\"><strong>Quality Control&nbsp;of MUG Test<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><span style=\"color: #000000;\"><strong>Positive: <\/strong><em>Escherichia coli <\/em>(ATCC25922)<\/span><\/p>\n\n\n\n<p><span style=\"color: #000000;\"><strong>Negative:<\/strong> <em>Klebsiella pneumoniae <\/em>(ATC13883)<\/span><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"references\"><\/span><span style=\"color: #000000;\"><strong>References <\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ol>\n<li><span style=\"color: #000000;\">Tille P.M. 2014. Bailey and Scott\u2019s diagnostic microbiology. Thirteen edition. Mosby, Inc., an affiliate of Elsevier Inc. 3251 Riverport Lane. St. Louis. Missouri 63043<\/span><\/li>\n\n\n\n<li><span style=\"color: #000000;\">Remel MUG disk. 2010. 12076 Santa Fe Drive, Lenexa, KS 66215, USA <a style=\"color: #000000;\" href=\"https:\/\/assets.thermofisher.com\/TFS-Assets\/LSG\/manuals\/IFU21135.pdf\" target=\"_blank\" rel=\"noopener\">https:\/\/assets.thermofisher.com\/TFS-Assets\/LSG\/manuals\/IFU21135.pdf<\/a><\/span><\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>Objective of MUG Test To identify various genera of Enterobacteriaceae and verotoxin-producing Escherichia coli. Principle&nbsp;of MUG Test MUG is an acronym for 4-methylumbelliferyl-beta-D-glucuronide, a fluorogenic substrate of \u03b2-glucuronidase. \u03b2-D-Glucuronidase is &#8230; <a title=\"MUG Test- Objective, Principle,\u00a0Procedure,\u00a0Result, Limitations\" class=\"read-more\" href=\"https:\/\/microbenotes.com\/4-methylumbelliferyl-%ce%b2-d-glucuronide-mug-test\/\" aria-label=\"Read more about MUG Test- Objective, Principle,\u00a0Procedure,\u00a0Result, Limitations\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":543,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[702],"tags":[706,707,890,891,892,893,894,895,896,897],"custom":{"td_video":"","featured_image":"https:\/\/microbenotes.com\/wp-content\/uploads\/2018\/06\/4-Methylumbelliferyl-\u03b2-D-Glucuronide-MUG-Test.png","author":{"name":"Sagar Aryal","avatar":"https:\/\/secure.gravatar.com\/avatar\/862472ea06500d4318f1ad82addb608e?s=96&d=mm&r=g"},"categories":[{"term_id":702,"name":"Biochemical Test","slug":"biochemical-test","term_group":0,"term_taxonomy_id":702,"taxonomy":"category","description":"<strong>Biochemical tests are the tests that are performed on different bacteria for their identification on the basis of their biochemical activities towards different biochemical compounds.<\/strong>\r\n<ul>\r\n \t<li>Biochemical tests are one of the traditional methods for the identification of microorganisms, usually performed with phenotypic identification.<\/li>\r\n \t<li>For many years these methods were employed extensively, and they continue to be used nowadays, especially in some laboratory routines where a particular type of microorganism has to be identified rapidly.<\/li>\r\n \t<li>The ability of microorganisms to utilize certain biomolecules, resulting in useful organic compounds for themselves forms the basis of various biochemical tests.<\/li>\r\n \t<li>Biochemical tests are of different types, where the identification or distinction between different microorganisms is made on various bases.<\/li>\r\n \t<li>One of the traditional methods commonly used is a simple visual detection of the growth of the organism in the presence of essential nutrients by increased turbidity in the liquid medium.<\/li>\r\n \t<li>In other tests, however, the results are based on the change in color of the medium as a result of the change in the pH of the medium.<\/li>\r\n \t<li>Microorganisms can be classified into different groups on the basis of their reaction to such tests. Some tests even allow the distinction of microorganisms to the species level.<\/li>\r\n \t<li>Biochemical tests are thus, essential as they are inexpensive and relatively simple to perform.<\/li>\r\n \t<li>The physiology of bacteria and other microorganisms differs from one another, which allows for the differentiation of such microorganisms.<\/li>\r\n \t<li>Biochemical tests, however, have some disadvantages. Despite being inexpensive and allowing both quantitative and qualitative information about the diversity of microorganisms present in a sample, these methods are laborious and time-consuming, and results are only observed after several days.<\/li>\r\n \t<li>In some cases, false positives are obtained, especially when considering similar microbial species.<\/li>\r\n<\/ul>","parent":0,"count":114,"filter":"raw","cat_ID":702,"category_count":114,"category_description":"<strong>Biochemical tests are the tests that are performed on different bacteria for their identification on the basis of their biochemical activities towards different biochemical compounds.<\/strong>\r\n<ul>\r\n \t<li>Biochemical tests are one of the traditional methods for the identification of microorganisms, usually performed with phenotypic identification.<\/li>\r\n \t<li>For many years these methods were employed extensively, and they continue to be used nowadays, especially in some laboratory routines where a particular type of microorganism has to be identified rapidly.<\/li>\r\n \t<li>The ability of microorganisms to utilize certain biomolecules, resulting in useful organic compounds for themselves forms the basis of various biochemical tests.<\/li>\r\n \t<li>Biochemical tests are of different types, where the identification or distinction between different microorganisms is made on various bases.<\/li>\r\n \t<li>One of the traditional methods commonly used is a simple visual detection of the growth of the organism in the presence of essential nutrients by increased turbidity in the liquid medium.<\/li>\r\n \t<li>In other tests, however, the results are based on the change in color of the medium as a result of the change in the pH of the medium.<\/li>\r\n \t<li>Microorganisms can be classified into different groups on the basis of their reaction to such tests. Some tests even allow the distinction of microorganisms to the species level.<\/li>\r\n \t<li>Biochemical tests are thus, essential as they are inexpensive and relatively simple to perform.<\/li>\r\n \t<li>The physiology of bacteria and other microorganisms differs from one another, which allows for the differentiation of such microorganisms.<\/li>\r\n \t<li>Biochemical tests, however, have some disadvantages. Despite being inexpensive and allowing both quantitative and qualitative information about the diversity of microorganisms present in a sample, these methods are laborious and time-consuming, and results are only observed after several days.<\/li>\r\n \t<li>In some cases, false positives are obtained, especially when considering similar microbial species.<\/li>\r\n<\/ul>","cat_name":"Biochemical Test","category_nicename":"biochemical-test","category_parent":0}]},"_links":{"self":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts\/598"}],"collection":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/comments?post=598"}],"version-history":[{"count":0,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts\/598\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/media\/543"}],"wp:attachment":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/media?parent=598"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/categories?post=598"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/tags?post=598"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}