[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$fy8vpZ7NoMU3qGutZqmgLwaFp12FIRHV5ucQgoyRZG8Y":32,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":47},[4,8,12,16,20,24,28],{"title":5,"slug":6,"path":7},"About Microbeonline.com","about-microbeonline-com","\u002Fabout-microbeonline-com\u002F",{"title":9,"slug":10,"path":11},"About Me","about-me","\u002Fabout-microbeonline-com\u002Fabout-me\u002F",{"title":13,"slug":14,"path":15},"Advertise with Us","advertise-us","\u002Fadvertise-us\u002F",{"title":17,"slug":18,"path":19},"Privacy Policy","privacy-policy","\u002Fprivacy-policy\u002F",{"title":21,"slug":22,"path":23},"Abbreviations","abbreviations","\u002Fabbreviations\u002F",{"title":25,"slug":26,"path":27},"Microbes","microbes","\u002Fmicrobes\u002F",{"title":29,"slug":30,"path":31},"Books","recommended-books","\u002Frecommended-books\u002F",{"type":33,"data":34},"blog",{"slug":35,"title":36,"description":36,"seoTitle":37,"seoDescription":37,"author":38,"createdDate":39,"lastUpdatedDate":40,"draft":41,"category":42,"image":37,"body":43,"faq":44,"tags":45,"related":46},"actinomyces-properties-disease-laboratory-diagnosis","Actinomyces: Properties, Disease, Lab Diagnosis",null,"Acharya Tankeshwar","2021-04-10","2025-12-29",false,"bacteriology","*Actinomyces* comprised a heterogeneous group of gram-positive, pleomorphic bacilli. Other properties are:\n\n- facultatively anaerobic or microaerophilic,\n- non-spore-forming,\n- non-acid-fast (this is a contrast to another bacteria, *Nocardia*which is acid-fast)\n- Non-motile\n\n### Mode of infection\n\nInfection of *Actinomyces* is mostly endogenous and may result from local trauma such as a broken jaw or dental extraction.\n\n### Infections\n\n![](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FActinomyces-infection-and-normal-flora.jpg)Many *Actinomyces* species are part of the oral microflora of humans. Some species of *Actinomyces* are found in supragingival and subgingival plaques of adult patients suffering from periodontitis and gingivitis. These same organisms also play a significant role in the development of root-surface caries. *Actinomyces* also cause classical actinomycosis, wound infections, abscesses, and genital tract infections.\n\n> Actinomycosis is a chronic suppurative and granulomatous infection characterized by multiple abscess formation of sinuses, discharge containing granules, and on later stage; fibrosis and tissue destruction. The typical lesion of actinomycosis appears as a hard, non-tender swelling that develops slowly and eventually drains pus through sinus tracts. Hard, yellow granules (sulfur granules) composed of a mass of filaments are formed in pus.\n\n*Actinomyces israelii* and *Arachnia* species are the most common causes of actinomycosis in humans. Actinomycosis can affect any organ and characteristically manifests as:\n\n![](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FActinomyces-infection.jpg)1. **Cervicofacial actinomycosis**: It is associated with poor dentition, dental manipulations, and other head-and-neck infections (e.g., otitis, mastoiditis).\n2. **CNS actinomycosis**: It results after hematogenous dissemination or by direct extension of actinomycotic infections in the head\u002Fneck areas. Patients usually present with chronic meningitis or meningoencephalitis complicated by the development of subdural empyema, epidural and spinal abscesses, and cranial osteomyelitis. In 75% of cases, CNS actinomycosis presents with single or multiple brain abscesses, usually in the temporal or frontal lobes.\n3. **Thoracic actinomycosis**: It involves the chest and mediastinal region.\n4. **Abdominal actinomycosis**: Actinomycosis of the Ileocecal region.\n5. **Pelvic actinomycosis**: Pelvic actinomycosis can occur in women who have retained an intrauterine device for a long period of time.\n\n### Laboratory Diagnosis\n\n**Sample**\n\nBased on the affected site, the specimens collected include discharge from the sinuses or fistula, rarely bronchoalveolar lavage, sputum or tissue sections.\n\nDiagnosis in the laboratory is made by\n\n1. seeing gram-positive branching rods, especially in the presence of sulfur granules, and\n2. seeing growth when pus or tissue specimens are cultured under anaerobic conditions. Organisms can be identified by immunofluorescence.\n\n#### Direct Microscopy\n\nPus discharge is thoroughly washed in saline in a test tube and the sediment is collected that contains gritty, white or yellowish sulfur granules, of <5 mm in size. Granules are crushed between two slides and smears are made.\n\n**Gram-staining (Brown-Brenn modification)**\n\nIt shows a central mass of gram-positive filamentous bacilli, radiating peripherally with hyaline, club-shaped ends. Clubs are composed of complexes formed due to interaction of bacteria derived polysaccharide and protein with host cell salts and polypeptides.\n\nGranules of actinomycosis are hard and not emulsifiable which differentiates them from granules produced other conditions. *Actinomyces* species can also be detected directly from the sample by methods such as:\n\n1. Fluorescent antibody techniques using fluorescent-tagged species-specific monoclonal antibodies.\n2. Fluorescent in situ hybridization (FISH) using species-specific probes.\n\n> Note that in contrast to N.asteroides, Actinomycesis not acid-fast.\n\n![ - Actinomycesin culture and Gram-stain](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002Factinomyces-culture-and-gram-stain.png)Figure: Actinomyces in culture and Gram-stain\n\n**Histopathological staining** such as hematoxylin-eosin and Gomori’s stained tissue sections may reveal granules composed of eosinophilic clubs surrounding basophilic filaments and foamy macrophages (sun-rays appearance).\n\n#### Culture\n\nPus containing sulfur granules are washed and cultured anaerobically at 37°C on media such as:\n\n1. **Thioglycollate broth**: Growth of *A. israelii* resembles fluffy balls at the bottom of the tube, this can be differentiated from other species (*A. bovis* produces uniform turbidity).\n2. **Brain heart infusion (BHI) agar**: It forms small spidery colonies at 48 hours which become enlarged and heaped up in 10 days.\n\n**Species identification**\n\nIt is done when the culture isolate is subjected to:\n\n1. Biochemical reactions\n2. Gas-liquid chromatography (GLC) for detection of the products of glucose metabolism.\n3. Molecular methods, such as PCR-RFLP are also available for speciation.\n\n### Treatment and prevention\n\nTreatment consists of prolonged administration of penicillin G, coupled with surgical drainage. There is no significant resistance to penicillin G. No vaccine or prophylactic drug is available.\n\n**References and Further Readings**\n\n1. Procop, G. W., & Koneman, E. W. (2016). [Koneman’s Color Atlas and Textbook of Diagnostic Microbiology](https:\u002F\u002Famzn.to\u002F2vRkUvk)(Seventh, International edition). Lippincott Williams and Wilkins.\n2. Tille, P. (2017). *Bailey & Scott’s Diagnostic Microbiology* (14 edition). Mosby.",[],[],[],[48,54,61,66,70,74,79,84,88,92],{"slug":49,"name":38,"description":50,"image":51,"body":52,"postCount":53},"acharya-tankeshwar","Editor-in-chief","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Ftankeshwar-acharya-author-microbeonline.jpg","***Tankeshwar Acharya, MSc (Medical Microbiology)***\n\n*Tankeshwar Acharya is an Assistant Professor in the Department of Microbiology at Patan Academy of Health Sciences (PAHS), Nepal, where he has been teaching and practicing clinical microbiology for over 14 years. He is the founder of Microbe Online, one of the leading free microbiology education resources on the web, covering bacteriology, mycology, parasitology, immunology, and clinical laboratory diagnostics written from direct experience in both the classroom and the diagnostic laboratory.*",433,{"slug":55,"name":56,"description":57,"image":58,"body":59,"postCount":60},"ashma-shrestha","Ashma Shrestha","SEO Copywriter and Science Communicator\nKathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fashma-shrestha.png","Ashma Shrestha holds a Master of Science in Medical Microbiology from the Institute of Science and Technology (IOST), Tribhuvan University, Nepal, where she developed a strong foundation in virology, molecular biology, and diagnostic microbiology.\n\nShe now works as an SEO Copywriter at Resolution Digital, where she combines her scientific training with research-driven content strategy. She is certified in Google Analytics and Google Business Profile (GBP), and brings a data-informed approach to science communication writing content that is not only accurate but structured to reach and serve the students who need it most.\n\nAt microbeonline, Ashma contributes articles primarily in virology and molecular biology, areas she finds most compelling for their mechanistic depth and their growing clinical relevance. Her writing reflects the same standard the site is built on: factual rigor, clear explanation of the *why* behind microbiology concepts, and content that helps students move from memorization to genuine understanding.\n\nShe is passionate about making complex microbiological concepts accessible without sacrificing accuracy; a skill that sits at the intersection of her scientific training and her professional work in content and SEO.",81,{"slug":62,"name":63,"description":64,"image":37,"body":37,"postCount":65},"sushmita-baniya","Sushmita Baniya","Author \u002F Contributor",32,{"slug":67,"name":68,"description":64,"image":37,"body":37,"postCount":69},"samikshya-acharya","Samikshya Acharya",20,{"slug":71,"name":72,"description":64,"image":37,"body":37,"postCount":73},"alisha-tripathi","Alisha Tripathi",6,{"slug":75,"name":76,"description":77,"image":37,"body":37,"postCount":78},"aastha-shrestha","Aastha Shrestha"," Author \u002F Contributor",10,{"slug":80,"name":81,"description":82,"image":37,"body":37,"postCount":83},"guest-author","Guest Author","Guest Author \u002F Contributor",2,{"slug":85,"name":86,"description":64,"image":37,"body":37,"postCount":87},"srijana-khanal","Srijana Khanal",18,{"slug":89,"name":90,"description":82,"image":37,"body":37,"postCount":91},"dr-poonam-acharya","Dr. Poonam Acharya",1,{"slug":93,"name":94,"description":64,"image":37,"body":95,"postCount":96},"nisha-rijal","Nisha Rijal","**Nisha Rijal** is a microbiologist and quality assurance specialist. She served for nearly 12 years as a microbiologist at the National Public Health Laboratory (NPHL), Nepal's national reference laboratory, and continues to work as a consultant microbiologist in international public health organization. ",51]