{"id":36305,"date":"2022-01-15T13:54:04","date_gmt":"2022-01-15T08:09:04","guid":{"rendered":"https:\/\/microbenotes.com\/?p=36305"},"modified":"2022-01-15T13:54:06","modified_gmt":"2022-01-15T08:09:06","slug":"corynebacterium-diphtheriae","status":"publish","type":"post","link":"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/","title":{"rendered":"Corynebacterium diphtheriae (Klebs-L\u00f6ffler bacillus)- An Overview"},"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\/corynebacterium-diphtheriae\/#habitat-of-corynebacterium-diphtheriae\" title=\"Habitat&nbsp;of Corynebacterium diphtheriae\">Habitat&nbsp;of Corynebacterium diphtheriae<\/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\/corynebacterium-diphtheriae\/#morphology-of-corynebacterium-diphtheriae\" title=\"Morphology&nbsp;of Corynebacterium diphtheriae\">Morphology&nbsp;of Corynebacterium diphtheriae<\/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\/corynebacterium-diphtheriae\/#genome-of-corynebacterium-diphtheriae\" title=\"Genome of Corynebacterium diphtheriae\">Genome of Corynebacterium diphtheriae<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#cultural-characterisitics-of-corynebacterium-diphtheriae\" title=\"Cultural Characterisitics of Corynebacterium diphtheriae\">Cultural Characterisitics of Corynebacterium diphtheriae<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#1-tellurite-medium\" title=\"1. Tellurite Medium\">1. Tellurite Medium<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#2-sheep-blood-agar\" title=\"2. Sheep Blood Agar\">2. Sheep Blood Agar<\/a><\/li><\/ul><\/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\/corynebacterium-diphtheriae\/#click-here-for-biochemical-test-of-corynebacterium-diphtheriae\" title=\"Click here for Biochemical Test of Corynebacterium diphtheriae\">Click here for Biochemical Test of Corynebacterium diphtheriae<\/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\/corynebacterium-diphtheriae\/#pathogenesis-of-corynebacterium-diphtheriae\" title=\"Pathogenesis of Corynebacterium diphtheriae\">Pathogenesis of Corynebacterium diphtheriae<\/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\/corynebacterium-diphtheriae\/#clinical-manifestations-of-corynebacterium-diphtheriae\" title=\"Clinical manifestations&nbsp;of Corynebacterium diphtheriae\">Clinical manifestations&nbsp;of Corynebacterium diphtheriae<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#respiratory-diphtheria\" title=\"Respiratory diphtheria\">Respiratory diphtheria<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#cutaneous-diphtheria\" title=\"Cutaneous diphtheria\">Cutaneous diphtheria<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#laboratory-diagnosis-of-corynebacterium-diphtheriae\" title=\"Laboratory diagnosis of Corynebacterium diphtheriae\">Laboratory diagnosis of Corynebacterium diphtheriae<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#specimen\" title=\"Specimen\">Specimen<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#microscopy\" title=\"Microscopy\">Microscopy<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#culture\" title=\"Culture\">Culture<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#biochemical-testing\" title=\"Biochemical testing\">Biochemical testing<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#carbohydrate-fermentation\" title=\"Carbohydrate fermentation\">Carbohydrate fermentation<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#toxigenicity-testing\" title=\"Toxigenicity Testing\">Toxigenicity Testing<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#antibody-detection\" title=\"Antibody detection\">Antibody detection<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#treatment-of-corynebacterium-diphtheriae\" title=\"Treatment&nbsp;of Corynebacterium diphtheriae\">Treatment&nbsp;of Corynebacterium diphtheriae<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#prevention-and-control-of-corynebacterium-diphtheriae\" title=\"Prevention and control&nbsp;of Corynebacterium diphtheriae\">Prevention and control&nbsp;of Corynebacterium diphtheriae<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/#references\" title=\"References\">References<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"habitat-of-corynebacterium-diphtheriae\"><\/span><strong>Habitat&nbsp;of <em>Corynebacterium diphtheriae<\/em><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ol><li><em>Corynebacterium diphtheriae <\/em>is found in nasopharynx as well as in skin lesions, which actually represent a reservoir for the spread of diphtheria.<\/li><li>Also found in mouth, throat, nose, skin and wound of infected person.<\/li><li>Animals do not easily contract diphtheria.<\/li><li>Patients carry toxigenic organism upto 3 months after infection.<\/li><\/ol>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"morphology-of-corynebacterium-diphtheriae\"><\/span><strong>Morphology&nbsp;of <em>Corynebacterium diphtheriae<\/em><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ol><li><em>Corynebacterium diphtheriae<\/em> are gram +ve rod shaped bacteria.<\/li><li>Club shaped<\/li><li>Irregular swelling at one end or both end gives them the \u201cClub Shaped\u201d appearance.<\/li><li>Thin and slender, long, curved<\/li><li>Also known as Kleb\u2019s-Loeffler Bacillus.<\/li><li>3 \u00b5m to 5 \u00b5m x 0.5 \u00b5m to 0.8 \u00b5m in diameter<\/li><li>Non-capsulated<\/li><li>Non-sporing<\/li><li>Non-motile<\/li><li>Chinese letter arrangement, V or L shaped<\/li><li>Pleomorphic (Changes in shape and size of the bacteria)<\/li><li>Seen in pairs or in small groups, appears in clusters<\/li><li>Arranged in various angles to each other.<\/li><li>Forms granules (metachromatic granules)<\/li><li>Granules are the store house of energy<\/li><li>Lipid rich cell wall contains mesodiaminopimelic acid, arabino-galactam polymers and short chain mycolic acid.<\/li><li>Pili present<\/li><li>Alberts&#8217;s stain and Ponder&#8217;s stain shows metachromatic granules formed in the polar regions<\/li><li>Appears green in Alberts&#8217;s stain along with bluish black metachromatic granules at the poles.<\/li><\/ol>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"750\" height=\"393\" src=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Morphology-of-Corynebacterium-diphtheriae.jpeg\" alt=\"\" class=\"wp-image-36310\" srcset=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Morphology-of-Corynebacterium-diphtheriae.jpeg 750w, https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Morphology-of-Corynebacterium-diphtheriae-300x157.jpeg 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" \/><figcaption><strong>Figure: Morphology\u00a0of <em>Corynebacterium diphtheriae<\/em>. Image Source: <a href=\"https:\/\/phil.cdc.gov\/details.aspx?pid=7323\" target=\"_blank\" rel=\"noreferrer noopener\">CDC\/ Dr. P.B. Smith<\/a> and Illustrator: <a href=\"https:\/\/phil.cdc.gov\/Details.aspx?pid=22877\" target=\"_blank\" rel=\"noreferrer noopener\">Jennifer Oosthuizen<\/a>.<\/strong><\/figcaption><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"genome-of-corynebacterium-diphtheriae\"><\/span><strong>Genome of <em>Corynebacterium diphtheriae<\/em><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ol><li>Contains 2389 Genes<\/li><li>Protein encoding genes: 2272<\/li><li>Have 69 Structural RNA gene<\/li><li>Genome Length: 2,488,635 nucleotide<\/li><li>87% are coding<\/li><li>G+C Content: 53%<\/li><li>No plasmid<\/li><li>Contains Pathogenicity Islands (PAI\u2019s)<\/li><\/ol>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"cultural-characterisitics-of-corynebacterium-diphtheriae\"><\/span><strong>Cultural Characterisitics of<em> <strong><em>Corynebacterium diphtheriae<\/em><\/strong><\/em><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul><li><em>Corynebacterium diphtheriae<\/em> grows well on simple nutrient agar and agar containing blood at the mesophilic temperature range. The growth, however, is not observed on enteric agar formulation and on <a href=\"https:\/\/microbenotes.com\/macconkey-agar\/\" target=\"_blank\" rel=\"noreferrer noopener\">MacConkey agar<\/a>.<\/li><li>The growth of <em>C. <em>diphtheriae<\/em><\/em> on agar media is accomplished by growing it on media containing compounds like nalidixic acid and colistin sulfate that are inhibitory to gram-negative bacteria.<\/li><li>Like most corynebacteria, <em>C. <em>diphtheriae<\/em><\/em> also grows well at 37 \u00b0C or within the mesophilic temperature range.<\/li><li>Some strains of <em>C. <em>diphtheriae<\/em><\/em> are facultative anaerobes that grow well in a CO<sub>2<\/sub>-enriched atmosphere.<\/li><li>The most important culture media used for the isolation of <em>C. <em>diphtheriae<\/em><\/em> is the Sheep Blood Agar (SBA). Other selective media include cystine-tellurite blood agar (CTBA) or freshly prepared Tinsdale medium.<\/li><li>The tellurite present in the medium inhibits the growth of other noncorynebacterium species, but some strains of <em>C. <em>diphtheriae<\/em><\/em> are sensitive to potassium tellurite and require the SBA agar.<\/li><li>For the direct culturing of <em>C. <em>diphtheriae<\/em><\/em>, Tinsdale medium is the best medium, but the medium has a short shelf life.<\/li><li>The identification of <em>C. <em>diphtheriae<\/em><\/em> on Tinsdale medium is efficient in the identification of <em>C. <em>diphtheriae<\/em><\/em> as the bacteria shows both tellurite reductase and cystinase activity.<\/li><li><em>C. <em>diphtheriae<\/em><\/em> belongs to the Hazard group 2 organisms which might require Containment Level 3 conditions for processing in some cases due to aerosol production.<\/li><li>Growth on serum-based media like Loeffler slants produce colonies with pleomorphic rods, some of which might be club-shaped. The cells might have a beaded appearance due to the terminal reddish-purple polyphosphate granules.<\/li><li>Members of <em>C. <em>diphtheriae<\/em><\/em> have been divided into four different biotypes based on their colony morphology on different agar medium.<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1000\" height=\"797\" src=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Cultural-Characterisitics-of-Corynebacterium-diphtheriae.jpeg\" alt=\"Cultural Characterisitics of Corynebacterium diphtheriae\" class=\"wp-image-36314\" srcset=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Cultural-Characterisitics-of-Corynebacterium-diphtheriae.jpeg 1000w, https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Cultural-Characterisitics-of-Corynebacterium-diphtheriae-300x239.jpeg 300w, https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Cultural-Characterisitics-of-Corynebacterium-diphtheriae-768x612.jpeg 768w\" sizes=\"(max-width: 1000px) 100vw, 1000px\" \/><figcaption>Figure: Corynebacterium diphtheria on a blood agar plate (BAP) and McLeod&#8217;s growth medium. Images Source: <a href=\"https:\/\/phil.cdc.gov\/default.aspx\" target=\"_blank\" rel=\"noreferrer noopener\">CDC\/ Dr. W.A. Clark<\/a>.<\/figcaption><\/figure>\n\n\n\n<ul><li>The following are some cultural characteristics of <em>C. diphtheriae<\/em> on different culture media:<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"1-tellurite-medium\"><\/span><strong>1. Tellurite Medium<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul><li>The colony morphology of different biotypes of <em>C. <em>diphtheriae<\/em><\/em> on the tellurite medium might be different.<\/li><li><em>C. <em>diphtheriae<\/em><\/em> biotype biovar gravis forms dull, grey-coloured opaque colonies that have an average diameter of 2 mm. The surface of the colonies is matt, friable that tends to break into small segments when touched with a wire.<\/li><li><em>C. <em>diphtheriae<\/em><\/em> biotype biovar mitis produces opaque grey or black colonies ranging in size between 1.5-2 mm in diameter. The colonies have entire edge and glossy smooth surface. The variation in size is common in this biotype.<\/li><li><em>C. <em>diphtheriae<\/em><\/em> biotype biovar intermedius forms small grey-coloured shiny colonies that are comparatively smaller in size (0.5-1.0 mm in diameter). The colonies are discrete and translucent on the surface.<\/li><li><em>C. <em>diphtheriae<\/em><\/em> biotype biovar belfanti produces grey or black-coloured colonies of 1.5-2.0 mm diameter. The colonies have an entire edge and glossy smooth surface.<\/li><li>The black coloured colonies of <em>C. <em>diphtheriae<\/em><\/em> on tellurite agar are due to the tellurite reductase activity of the bacteria. Besides, these can also produce a brown halo around the colonies due to the cystinase activity.<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"2-sheep-blood-agar\"><\/span><strong>2. Sheep Blood Agar<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul><li>Small grey to black-coloured colonies is observed on the sheep blood agar. The colonies usually range between 1-2 mm in diameter.<\/li><li><em>C. <em>diphtheriae<\/em><\/em> exhibits hemolytic activity on blood agar, which might differ in different biotypes.<\/li><li><em>C. <em>diphtheriae<\/em><\/em> biotype biovar gravis is non-hemolytic and thus doesn\u2019t cause clearing of the media.<\/li><li>The rest three biovars of the species; mitis, intermedius and belfanti produce colonies that exhibit a small zone of \u03b2-hemolysis on the agar.<\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"click-here-for-biochemical-test-of-corynebacterium-diphtheriae\"><\/span><strong><a href=\"https:\/\/microbenotes.com\/biochemical-test-of-corynebacterium-diphtheriae\/\" target=\"_blank\" rel=\"noreferrer noopener\">Click here for Biochemical Test of <em>Corynebacterium diphtheriae<\/em><\/a><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"pathogenesis-of-corynebacterium-diphtheriae\"><\/span><strong>Pathogenesis of <em>Corynebacterium diphtheriae<\/em><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul><li>In nature, <em>C diphtheriae <\/em>occurs in the respiratory tract, in wounds, or on the skin of infected persons or normal carriers.<\/li><li>It is spread by droplets or by contact to susceptible individuals; the bacilli then grow on mucous membranes or in skin abrasions, and those that are toxigenic start producing toxin.<\/li><li>Diphtheria toxin is the major virulence factor of <em>C. diphtheria<\/em> and is a heat-labile, single-chain, three domain polypeptide (62 kDa) that can be lethal in a dose of 0.1 \u03bcg\/kg body weight.<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1000\" height=\"491\" src=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Mechanism-of-action-of-Diphtheria-toxin-DT.jpg\" alt=\"Mechanism of action of Diphtheria toxin (DT)\" class=\"wp-image-36316\" srcset=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Mechanism-of-action-of-Diphtheria-toxin-DT.jpg 1000w, https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Mechanism-of-action-of-Diphtheria-toxin-DT-300x147.jpg 300w, https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Mechanism-of-action-of-Diphtheria-toxin-DT-768x377.jpg 768w\" sizes=\"(max-width: 1000px) 100vw, 1000px\" \/><figcaption>Figure: Mechanism of action of diphtheria toxin (DT). Image Source: <a href=\"https:\/\/www.nature.com\/articles\/s41572-019-0131-y\" target=\"_blank\" rel=\"noreferrer noopener\">Naresh Chand Sharma et al. 2019<\/a>.<\/figcaption><\/figure>\n\n\n\n<ul><li>The tox gene that codes for the exotoxin is introduced into strains of <em>C. diphtheriae <\/em>by a lysogenic bacteriophage, \u03b2-phage.<\/li><li>Two processing steps are necessary for the active gene product to be secreted: (1) proteolytic cleavage of the leader sequence from the Tox protein during secretion from the bacterial cell and (2) cleavage of the toxin molecule into two polypeptides (A and B) that remain attached by a disulfide bond.<\/li><li>Three functional regions exist on the toxin molecule: a catalytic region on the A subunit and a receptor-binding region and a translocation region on the B subunit.<\/li><li>The receptor for the toxin is heparin-binding epidermal growth factor, which is present on the surface of many eukaryotic cells, particularly heart and nerve cell.<\/li><li>The binding of the receptor domain to host cell membrane proteins CD-9 and heparin-binding epidermal growth factor (HB-EGF) triggers the entry of the toxin into the cell through receptor-mediated endocytosis.<\/li><li>Acidification of the translocation domain within a developing endosome leads to creation of a protein channel that facilitates movement of Fragment A into the host cell cytoplasm.<\/li><li>The A subunit then terminates host cell protein synthesis by inactivating elongation factor-2 (EF-2) which is required for translocation of polypeptidyl-transfer RNA from the acceptor to the donor site on the eukaryotic ribosome.<\/li><li>Toxin Fragment A inactivates EF-2 by catalyzing a reaction that yields free nicotinamide plus an inactive adenosine diphosphate-ribose-EF-2 complex (ADP-ribosylation).<\/li><li>Because the turnover of EF-2 is very slow and approximately only one molecule per ribosome is present in a cell, it has been estimated that one exotoxin molecule can inactivate the entire EF-2 content in a cell, completely terminating host cell protein synthesis.<\/li><li>It is assumed that the abrupt arrest of protein synthesis is responsible for the necrotizing and neurotoxic effects of diphtheria toxin.<\/li><li>Toxin synthesis \u00a0by lysogenized <em>C diptheriae<\/em> is regulated by a chromosomally encoded element, diphtheria toxin repressor (DTxR) which is \u00a0activated in the presence of high iron concentrations, and can bind to the toxin gene operator and prevent toxin production.<\/li><li>Low iron concentration and other factors such as osmolarity, amino acid concentrations and pH, however enhance the production of toxin.<\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"clinical-manifestations-of-corynebacterium-diphtheriae\"><\/span><strong>Clinical manifestations&nbsp;<\/strong><strong>of <em>Corynebacterium diphtheriae<\/em><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"respiratory-diphtheria\"><\/span><strong>Respiratory diphtheria<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul><li>Diphtheria toxin is absorbed into the mucous membranes and causes destruction of epithelium and a superficial inflammatory response.<\/li><li>The symptoms of diphtheria involving the respiratory tract develop after 2 to 4 days incubation period.<\/li><li>Organisms multiply locally on epithelial cells in the pharynx or adjacent surfaces and initially cause localized damage as a result of exotoxin activity.<\/li><li>The onset is sudden, with malaise, sore throat, exudative pharyngitis, and a low-grade fever.<\/li><li>The exudate evolves into a thick pseudomembrane composed of bacteria, lymphocytes, plasma cells, fibrin, and dead cells that can cover the tonsils, uvula, and palate and can extend up into the nasopharynx or down into the larynx<\/li><li>The regional lymph nodes in the neck enlarge, and there may be marked edema of the entire neck, with distortion of the airway, often referred to as \u201cbull neck\u201d clinically.<\/li><li>In critically ill patients, cardiac (necrosis of heart muscles) and neurologic complications (demylenation) is most significant.<\/li><li>Neurotoxicity is proportional to the severity of the primary disease, which is influenced by the patient\u2019s immunity.<\/li><li>The majority of patients with severe primary disease develop neuropathy, initially localized to the soft palate and pharynx, later involving oculomotor and ciliary paralysis, with progression to peripheral neuritis.<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"cutaneous-diphtheria\"><\/span><strong>Cutaneous diphtheria<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul><li>Cutaneous diphtheria is acquired through skin contact with other infected persons.<\/li><li>The organism colonizes the skin and gains entry into the subcutaneous tissue through breaks in the skin.<\/li><li>A papule develops first and then evolves into a chronic, non-healing ulcer, sometimes covered with a grayish membrane<\/li><li>Systemic signs can develop.<\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"laboratory-diagnosis-of-corynebacterium-diphtheriae\"><\/span><strong>Laboratory diagnosis of <em>Corynebacterium diphtheriae<\/em><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"specimen\"><\/span><strong>Specimen<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul><li>Dacron swabs from the nose, throat, or other suspected lesions must be obtained before antimicrobial drugs are\u00a0administered.<\/li><li>Swabs should be collected from beneath any visible membrane.<\/li><li>The swab should then be placed in semisolid transport media such as <a href=\"https:\/\/microbenotes.com\/amies-transport-medium\/\" target=\"_blank\" rel=\"noreferrer noopener\">Amies<\/a>.<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"794\" src=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Laboratory-diagnosis-of-Corynebacterium-diphtheriae-1024x794.webp\" alt=\"Laboratory diagnosis of Corynebacterium diphtheriae\" class=\"wp-image-36315\" srcset=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Laboratory-diagnosis-of-Corynebacterium-diphtheriae-1024x794.webp 1024w, https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Laboratory-diagnosis-of-Corynebacterium-diphtheriae-300x233.webp 300w, https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Laboratory-diagnosis-of-Corynebacterium-diphtheriae-768x596.webp 768w, https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Laboratory-diagnosis-of-Corynebacterium-diphtheriae.webp 1252w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><figcaption>Figure: <em>Corynebacterium<\/em> diagnostic algorithm. Image Source: <a href=\"https:\/\/www.nature.com\/articles\/s41572-019-0131-y\" target=\"_blank\" rel=\"noreferrer noopener\">Naresh Chand Sharma et al. 2019<\/a>.<\/figcaption><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"microscopy\"><\/span><strong>Microscopy<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul><li>Smears stained with alkaline methylene blue or Gram stain show beaded rods in typical arrangement.<\/li><li>Cells often contain metachromatic granules (polymetaphosphate), which stain bluish-purple with methylene blue.<\/li><li>In Gram staining, purple coloured beaded rods, angular and palisade arrangements that creates a \u2018Chinese character\u2019 effect is observed.<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"culture\"><\/span><strong>Culture<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul><li>Specimens should be inoculated to a blood agar plate and a selective medium such as a tellurite plate (eg: cystine-tellurite blood agar [CTBA] or modified Tinsdale\u2019s medium) and incubated at 37\u00b0C in 5% CO2.<\/li><li>Non \u03b2 hemolytic region on blood agar.<\/li><li>Tellurite inhibits the growth of most upper respiratory tract bacteria and gram-negative rods and is reduced by <em>C.&nbsp;<\/em><em>diphtheriae, <\/em>producing characteristic gray to black color on agar.<\/li><li>Degradation of cysteine by <em>C. diphtheriae <\/em>cysteinase activity produces a brown halo around the colonies.<\/li><li>Tinsdale medium is the best medium for recovering <em>C.&nbsp;<\/em><em>diphtheriae <\/em>in clinical specimens, but it has a short shelf life and requires addition of horse serum.<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"biochemical-testing\"><\/span><strong>Biochemical testing<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Catalase \u2013 positive<\/p>\n\n\n\n<p>Oxidase \u2013 negative<\/p>\n\n\n\n<p>Cystinase production \u2013 positive<\/p>\n\n\n\n<p>Pyrazinamidase activity \u2013 positive<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"carbohydrate-fermentation\"><\/span><strong>Carbohydrate fermentation<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Glucose \u2013 positive<\/p>\n\n\n\n<p>Maltose \u2013 positive<\/p>\n\n\n\n<p>Sucrose \u2013 negative<\/p>\n\n\n\n<p>Trehalose \u2013 negative<\/p>\n\n\n\n<p>Urease \u2013 negative<\/p>\n\n\n\n<p>Nitrate reduction \u2013 positive<\/p>\n\n\n\n<p>Gelatin liquefaction \u2013 negative<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"toxigenicity-testing\"><\/span><strong>Toxigenicity Testing<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul><li>All isolates of <em>C.<\/em><em> diphtheriae <\/em>should be tested for the production of exotoxin.<\/li><li>The gold standard for detection of diphtheria toxin is an in-vitro immunodiffusion assay by &nbsp;Elek-Ouchterlony immunodiffusion test (Elek test).<\/li><li>An alternative method is detection of the exotoxin gene using a polymerase chain reaction (PCR) based nucleic acid amplification method.<\/li><li>This test can detect the tox gene in clinical isolates and directly in clinical specimens (e.g., swabs from the diphtheritic membrane or biopsy material).<\/li><li>A positive culture result confirms a positive PCR assay.<\/li><li>A negative culture result after antibiotic therapy along with a positive PCR assay result suggests that the patient probably has diphtheria.<\/li><li>Although this test is rapid and specific, strains in which the tox gene is not expressed can give a positive signal.<\/li><li>Enzyme-linked immunosorbent assays can be used to detect diphtheria toxin from clinical&nbsp;<em>C diphtheria <\/em>isolates.<\/li><li>An immunochromatographic strip assay allows detection of diphtheria toxin in a matter of hours.<\/li><li>However ELISA and immunochromatographic assay are not widely used.<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"antibody-detection\"><\/span><strong>Antibody detection<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul><li>Measurement of antibodies to diphtheria toxin in serum collected before administration of antitoxin may support the diagnosis when cultures are negative.<\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"treatment-of-corynebacterium-diphtheriae\"><\/span><strong>Treatment&nbsp;<\/strong><strong>of <em>Corynebacterium diphtheriae<\/em><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul><li>The early administration of specific antitoxin against the toxin formed by the organisms at their site of entry and multiplication is done promptly.<\/li><li>The antitoxin should be given intravenously on the day the clinical diagnosis of diphtheria is made and need not be repeated.<\/li><li>Intramuscular injection may be used in mild cases.<\/li><li>Diphtheria antitoxin will only neutralize circulating toxin that is not bound to tissue.<\/li><li>Antimicrobial drugs (penicillin, macrolides) inhibit the growth of diphtheria bacilli.<\/li><li>Although these drugs have virtually no effect on the disease process, they arrest toxin production and assist public health efforts.<\/li><li>Erythromycin may be preferred to penicillin for elimination of the bacilli from the throat, particularly in treatment of persistent carriers.<\/li><li>Some strains are tolerant to the bactericidal action of penicillins, and treatment of complicated infections should contain an association with an aminoglycoside.<\/li><li>Patients should be placed in strict isolation, nursed by staff whose immunization history is documented and have daily platelet counts and electrocardiography.<\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"prevention-and-control-of-corynebacterium-diphtheriae\"><\/span><strong>Prevention and control&nbsp;<\/strong><strong>of <em>Corynebacterium diphtheriae<\/em><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul><li>Active immunization in childhood with diphtheria toxoid yields antitoxin levels that are generally adequate until adulthood.<\/li><li>Diphtheria toxoids are commonly combined with tetanus toxoid (Td) and with a cellular pertussis vaccine (DaPT) as a single injection to be used in initial immunization of children (three doses in the first year of life, 15\u201318 months of age and 4\u20136 years of age).<\/li><li>Young adults should be given boosters of toxoid because toxigenic diphtheria bacilli are not sufficiently prevalent in the population to provide the stimulus of subclinical infection with stimulation of resistance.<\/li><li>Levels of antitoxin decline with time, and many older persons have insufficient amounts of circulating antitoxin to protect them against diphtheria.<\/li><li>The principal aims of prevention are to limit the distribution of toxigenic diphtheria bacilli in the population and to maintain as high a level of active immunization as possible.<\/li><li>Bed rest, isolation to prevent secondary spread, and maintenance of an open airway in patients with respiratory diphtheria are all important.<\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"references\"><\/span><strong>References<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Chaudhary A, Pandey S. Corynebacterium Diphtheriae. [Updated 2021 Jun 29]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.\u00a0Available from: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK559015\/.<\/p>\n\n\n\n<p>Sharma, N.C., Efstratiou, A., Mokrousov, I.\u00a0<em>et al.<\/em>\u00a0Diphtheria.\u00a0<em>Nat Rev Dis Primers<\/em>\u00a0<strong>5,\u00a0<\/strong>81 (2019). https:\/\/doi.org\/10.1038\/s41572-019-0131-y.<\/p>\n\n\n\n<p>Murphy JR. Corynebacterium Diphtheriae. In: Baron S, editor. Medical Microbiology. 4th edition. Galveston (TX): University of Texas Medical Branch at Galveston; 1996. Chapter 32.\u00a0Available from: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK7971\/<\/p>\n\n\n\n<p>Lamichhane A, Radhakrishnan S. Diphtheria. [Updated 2021 Aug 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.\u00a0Available from: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK560911\/<\/p>\n\n\n\n<p>Hoskisson PA. Microbe Profile: Corynebacterium diphtheriae &#8211; an old foe always ready to seize opportunity.\u00a0<em>Microbiology (Reading)<\/em>. 2018;164(6):865-867. doi:10.1099\/mic.0.000627<\/p>\n\n\n\n<p>Edwards D, Kent D, Lester C, et al. Transmission of toxigenic\u00a0<em>Corynebacterium diphtheriae<\/em>\u00a0by a fully immunised resident returning from a visit to West Africa, United Kingdom, 2017 [published correction appears in Euro Surveill. 2018 Oct;23(42):].\u00a0<em>Euro Surveill<\/em>. 2018;23(39):1700681. doi:10.2807\/1560-7917.ES.2018.23.39.1700681<\/p>\n\n\n\n<p>Trost E, Blom J, Soares Sde C, et al. Pangenomic study of Corynebacterium diphtheriae that provides insights into the genomic diversity of pathogenic isolates from cases of classical diphtheria, endocarditis, and pneumonia.\u00a0<em>J Bacteriol<\/em>. 2012;194(12):3199-3215. doi:10.1128\/JB.00183-12<\/p>\n\n\n\n<p>Hoskisson PA. Microbe Profile: Corynebacterium diphtheriae &#8211; an old foe always ready to seize opportunity.\u00a0<em>Microbiology (Reading)<\/em>. 2018;164(6):865-867. doi:10.1099\/mic.0.000627<\/p>\n\n\n\n<p>Barksdale L. Corynebacterium diphtheriae and its relatives.\u00a0<em>Bacteriol Rev<\/em>. 1970;34(4):378-422. doi:10.1128\/br.34.4.378-422.1970<\/p>\n\n\n\n<p>Rosana Y, Prilandari LI, Ajisman R, Hartono TS, Yasmon A. Detection of toxin-producing\u00a0<em>Corynebacterium diphtheriae<\/em>\u00a0from throat swabs of diphtheria patients using duplex real-time PCR.\u00a0<em>Iran J Microbiol<\/em>. 2020;12(6):508-515. doi:10.18502\/ijm.v12i6.5024<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Habitat&nbsp;of Corynebacterium diphtheriae Corynebacterium diphtheriae is found in nasopharynx as well as in skin lesions, which actually represent a reservoir for the spread of diphtheria. Also found in mouth, throat, &#8230; <a title=\"Corynebacterium diphtheriae (Klebs-L\u00f6ffler bacillus)- An Overview\" class=\"read-more\" href=\"https:\/\/microbenotes.com\/corynebacterium-diphtheriae\/\" aria-label=\"Read more about Corynebacterium diphtheriae (Klebs-L\u00f6ffler bacillus)- An Overview\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":36310,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[364],"tags":[306,307,6038],"custom":{"td_video":"","featured_image":"https:\/\/microbenotes.com\/wp-content\/uploads\/2022\/01\/Morphology-of-Corynebacterium-diphtheriae.jpeg","author":{"name":"Sagar Aryal","avatar":"https:\/\/secure.gravatar.com\/avatar\/862472ea06500d4318f1ad82addb608e?s=96&d=mm&r=g"},"categories":[{"term_id":364,"name":"Bacteriology","slug":"bacteriology","term_group":0,"term_taxonomy_id":364,"taxonomy":"category","description":"<strong>Bacteriology is a branch or discipline of science that studies different characteristics of bacteria and their association with other organisms or disciplines.<\/strong>\r\n<ul>\r\n \t<li>Over the years, the discipline of bacteriology has evolved from the microbiological tests performed only by physicians, the application of the germ theory of disease and economic concerns relating to the spoilage of foods and wine to the use of bacteria to simpler forms of laboratory tests and the production of new nutritious food and antibiotics.<\/li>\r\n \t<li>The study of bacteria began with the discovery of the microscope and was mostly limited to experts and scientists of that time.<\/li>\r\n \t<li>The initial advances in pathogenic bacteriology began with the identification and characterization of bacteria associated with specific diseases.<\/li>\r\n \t<li>Nowadays, however, bacteriology is used in various other fields like food, pharmaceuticals, agriculture, and the environment.<\/li>\r\n \t<li>Significant advances made in bacteriology over the last century have resulted in the development of many useful vaccines like pneumococcal polysaccharide vaccine, diphtheria toxoid as well as antibiotics.<\/li>\r\n \t<li>At present, most bacterial diseases in humans and their infectious agents have been identified, although significant variants continue to evolve and sometimes emerge.<\/li>\r\n \t<li>Studies made in bacteriology have also allowed the use of gene recombination technology in bacteria to produce improved bacterial strains that can then be used in various areas.<\/li>\r\n \t<li>The importance of bacteriology continues to grow throughout the years as many diseases and disorders associated with almost all living beings are caused by bacteria.<\/li>\r\n \t<li>Studies of non-pathogenic bacteria that exist in a symbiotic relationship with plants and animals are even beneficial to said organisms.<\/li>\r\n \t<li>The identification and classification of bacteria into different groups have allowed for a convenient way of studying these bacteria and the formation of a separate branch, systemic bacteriology, that deals with taxonomy.<\/li>\r\n \t<li>Besides, bacteriological studies, subsequently, have also been divided into different areas like soil bacteriology, public-health bacteriology, industrial bacteriology, etc.<\/li>\r\n \t<li>Bacteriological studies have been the focal point for disease diagnosis and treatment, and their importance continues to grow with the emergence of new bacteria and associated diseases.<\/li>\r\n<\/ul>","parent":0,"count":124,"filter":"raw","cat_ID":364,"category_count":124,"category_description":"<strong>Bacteriology is a branch or discipline of science that studies different characteristics of bacteria and their association with other organisms or disciplines.<\/strong>\r\n<ul>\r\n \t<li>Over the years, the discipline of bacteriology has evolved from the microbiological tests performed only by physicians, the application of the germ theory of disease and economic concerns relating to the spoilage of foods and wine to the use of bacteria to simpler forms of laboratory tests and the production of new nutritious food and antibiotics.<\/li>\r\n \t<li>The study of bacteria began with the discovery of the microscope and was mostly limited to experts and scientists of that time.<\/li>\r\n \t<li>The initial advances in pathogenic bacteriology began with the identification and characterization of bacteria associated with specific diseases.<\/li>\r\n \t<li>Nowadays, however, bacteriology is used in various other fields like food, pharmaceuticals, agriculture, and the environment.<\/li>\r\n \t<li>Significant advances made in bacteriology over the last century have resulted in the development of many useful vaccines like pneumococcal polysaccharide vaccine, diphtheria toxoid as well as antibiotics.<\/li>\r\n \t<li>At present, most bacterial diseases in humans and their infectious agents have been identified, although significant variants continue to evolve and sometimes emerge.<\/li>\r\n \t<li>Studies made in bacteriology have also allowed the use of gene recombination technology in bacteria to produce improved bacterial strains that can then be used in various areas.<\/li>\r\n \t<li>The importance of bacteriology continues to grow throughout the years as many diseases and disorders associated with almost all living beings are caused by bacteria.<\/li>\r\n \t<li>Studies of non-pathogenic bacteria that exist in a symbiotic relationship with plants and animals are even beneficial to said organisms.<\/li>\r\n \t<li>The identification and classification of bacteria into different groups have allowed for a convenient way of studying these bacteria and the formation of a separate branch, systemic bacteriology, that deals with taxonomy.<\/li>\r\n \t<li>Besides, bacteriological studies, subsequently, have also been divided into different areas like soil bacteriology, public-health bacteriology, industrial bacteriology, etc.<\/li>\r\n \t<li>Bacteriological studies have been the focal point for disease diagnosis and treatment, and their importance continues to grow with the emergence of new bacteria and associated diseases.<\/li>\r\n<\/ul>","cat_name":"Bacteriology","category_nicename":"bacteriology","category_parent":0}]},"_links":{"self":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts\/36305"}],"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=36305"}],"version-history":[{"count":0,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts\/36305\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/media\/36310"}],"wp:attachment":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/media?parent=36305"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/categories?post=36305"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/tags?post=36305"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}