Agents of actinomycosis
N. asteroides complex and other species
Filamentous or beaded/branching, Gram positive bacillus
Filamentous Gram positive bacillus
Mouth, GI or GU flora
Previously healthy or co-morbidities (e.g., diabetes), poor dentition
Decreased cell mediated immunity
Occasionally strikes immunocompetant
Indurated tissue, fistula or sinus track with sulfur granules
Indurated with sulfur granules
Subacute to Indolent
Penicillin G, ampicillin/amoxicillin, antipseudomonal PCNs, most cephalosporins, macrolides, tetracycline, imipenem, clindamycin
Neither cefotaxime nor ceftriaxone are usually selected for Actinomyces infection but the limited experience is quite good. Main reason for selection is perceived need to treat other pathogens; in this context these drugs are reasonable.
Good drug for actinomycosis - good in vitro activity and a limited but very favorable published experience in vivo. As with penicillin - need high doses and long course.
Good drug for actinomycosis. The agents are susceptible and clinical experience seems good. An advantage is the availability of oral and parenteral forms. Some clinicians will start therapy with high IV doses of penicillin or clindamycin, and use doxycycline for a prolonged oral maintenance phase.
A good drug for actinomycosis. The published experience includes anecdotal cases with large thoracic lesions that totally resolved. For CNS involvement, it may be preferred to give meropenem, but experience with that drug is less.
This drug won’t work. Actinomyces are not susceptible in vitro. This means Actinomycetes are probably not true anaerobes.
Penicillin G: standard drug for actinomycosis. Need high doses given IV to penetrate a very fibrotic and dense lesion. The course must be long to achieve resolution and prevent relapse.
Preferred drug for oral treatment--either initially for mild-moderate infections, or maintenance therapy after initial parenteral course.
Comment: Disease is defined by location Cervicofacial is most common, then thoracic and abdominopelvic. Path -- crosses tissue planes and causes sinus tracts. Often mimcs tumor and other infections by imaging and clinical features. Treatment is long course of antibiotics.
Comment: Rare cause of infection in PWID, but endocarditis, septic pulmonary emboli or thrombophlebitis, soft tissue abscesses and prosthetic joint infections described. In this series, blood cultures were positive in three of the four patients.
Comment: In vitro data is often hard to come bywith this organism. Organisms is almost always susceptible to beta-lactam antibiotics (without need for beta-lactamase inhibitors), tetracyclines and vancomycin.
Comment: Case report of 8 year old patient with pneumonia complicated by empyema necessitatis. Culture yielded A. israelii and A. actinomycetccomitans. Treatment was drainage and doxycycline for 1 year.
Comment: CT anatomical features: parenchymal, bronchiectatic, endocbronchial and extrapulmonary.
Comment: Different than the usual actino--aerobic growth, microscopic morphology (no branching), and the types and location of infections. Abscesses and infected atheromas are the most frequent types of infections, followed by infected skin structures, endophthalmitis, and bacteremias, including endocarditis. This organism appears to have susceptiblity profile similar to other members.
Comment: Review of 40 cases of thoracic actinomycosis -- 17 had immediate surgery due to hemoptysis or concern for cancer. Antibiotic therapy to the other 23 was successful in 18 (78%); 5 failed and required surgery. The antibiotic failures received these drugs on an average of 10 months, but those who responded showed improvement within 2 months.
Comment: Case report of endobronchial actimnomyces associated with a fish bone swallowed 28 months prior to detection.
Comment: Case report -- abdominal wall mass treated with long course of penicillin for actinomycosis. Due to poor response the patient had surgical excision which the authors noted is indicated for suboptimal response or a malignant process cannot be ruled out.
Comment: Review of recent evidence that actinomycosis is a major factor in infected osteoradionecrosis and bisphosphonate-associated osteonecrosis of jaws. A. graevenitzii may be the causative agent. Diagnosis is based on histopathology.
Comment: 3 cases initially diagnosed as pelvic malignancy and treated surgically. The review noted the association with IUD, the mistake of aggressive surgery for presumed malignancy and the diagnosis based on histopathology
Comment: Authors review archived material for actinomycosis of jaws and found bisphosphonate-associated osteonecrosis (BON) in 60% and infected osteoradiionecrosis (IORN) in 36%. All cases showed actinomyces colonies in bone. PCR indicated A israeli in 7 of 7 decalcified tissue specimens.
Comment: Authors call attention to the common features of actinomyces and nocardiosis - both often cause chronic lung disease that simulates lung cancer or TB.
Comment: Chronic pulmonary actinomycosis typically presents as a segmental consolidation with frequent cavity formation. A broncholith can be secondarily infected resulting in endobronchial actinomycosis, often with distal obstructive pneumonia.
Comment: 87 strains tested to 12 antibiotics. All were sensitive to penicillin, ampicillin and beta-lactam/beta-lactamase inhibitors. All were resistant to ciprofloxacin. Linezolid showed good activity.
Comment: Actinomycetes were the most common bacteria on failed dental implants -A. odontolyticus > A. naeslundii = A. viscosus > A. israelii; A. georgiae, A. geroneseriae and A. graevenitzii were rare.
Comment: The authors argue that treatment may be <6 months on the basis of their experience with two cases (esophageal and cervicofacial).
Comment: In these 1997 cases, the predominant species were A. israelii (41%), A. gerencseriae (27%), A. naeslundii (9%), A. odontolyticus (1%), and P. propionicum (1%).
Comment: The authors review 18 cases. GI lesions showed concentric or eccentric bowel wall thickening; 17 pts had a pelvic or peritoneal mass with a mean diameter of 3.2cm adjacent to the involved bowel. Clinical features included abd pain, fever, leukocytosis & long term IUD use.
Comment: This is the third reported case of A. viscosusendocarditis, although a large number of cases involving other species of Actinomyces have been reported. All cases have involved natural valves and there appears to be a high frequency of embolic lesions.
Comment: Review of 22 cases resulted in the following definition of typical CT findings: chronic segmental air-space consolidation that contains low-attenuation areas with peripheral enhancement or adjacent pleural thickening.
Comment: Review of thoracic actinomycosis which is very similar in clinical features for pulmonary nocardiosis. The organisms look identical on gram stain, but actino is not a disease of the compromised host, is not weakly acid fast, will not respond to sulfonamides and may produce typical sulfur granules. Other diagnostic considerations in chronic inflammatory lung infections are TB, MOTT, endemic fungi and cryptococcosis as well as cancer & lymphomas.
Comment: Diagnostic methods include: 1) cultivation of the microbe (which is hard to do); 2) typical appearance on gram stain, especially with sulfur granules; and 3) fluorescent antibody (FA) stains that are available for 4 of the 6 agents of actinomycosis.
Comment: Reviews role of surgery - most cases respond to long courses of abx initially given IV. Main role of surgery is to establish dx, drain abscess, excise inflammatory masses that are near vital areas, debulk lesions that are unresponsive to abx.
Comment: A survey of 69,925 women with pap smear screened for actino with FA stain for A. israelii showed the prevalence in those with IUD use was 1.6-5.3%; it was never found in the absence of an IUD. It should be noted that the rates of A. israelii with IUDs was high, but the rate of pelvic actinomycosis was much lower.
Pulmonary thoracic actinomyces eroding through chest wall; Source: PG Auwaerter MD
Sulfur granules from chest wall sinus tract
Source: PG Auwaerter MD
Colonies of actinomyces make up sulphur granules.
Source: CDC/ Dr. Richard L. Levin, Greater Southeast Community Hospital, Washington, D.C.; Dr. V.R. Dowell
Gram-positive, beaded and branching rods (magnification 1125x) characteristic of actinomyces. Specimen from jaw area, often organisms may not grow in laboratory. Source: CDC/ Dr. Lucille Georg
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