Actinomyces meyeri , a Common Agent of Actinomycosis

• Published in: The American journal of the medical sciences 2016-07, Vol.352 (1), p.53-62
• Main Authors: Rolfe, Robert, MD, Steed, Lisa L., PhD, Salgado, Cassandra, MD, MS, Kilby, J. Michael, MD
• Format: Article
• Language: English
• Subjects: Acquired Immunodeficiency Syndrome - complications; Acquired Immunodeficiency Syndrome - epidemiology; Actinomyces - isolation & purification; Actinomyces meyeri; Actinomycosis; Actinomycosis - complications; Actinomycosis - epidemiology; Actinomycosis - microbiology; Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Clinical outcomes; Epidemiology; Female; Humans; Infant; Internal Medicine; Male; Middle Aged; Organ Transplantation - adverse effects; Retrospective Studies; Risk Factors; South Carolina - epidemiology; Young Adult
• ISSN: 0002-9629; 1538-2990
• DOI: 10.1016/j.amjms.2016.03.003

Abstract Background Actinomyces , particularly Actinomyces israelii , may cause indolent, persistent infections or represent normal mucosal flora, leading to management dilemmas. Materials and Methods Prompted by a refractory Actinomyces meyeri infection complicating AIDS, clinical data for all Actinomyces isolates at our hospital laboratory since 1998 were analyzed. Results A total of 140 cases had a positive result for Actinomyces cultures. Of 130 cases with adequate follow-up, 36 (28%) cases had end-organ or disseminated disease treated with prolonged antibiotics or surgery or both (Group 1). A. meyeri was more common than A. israelii (33% versus 8%; P < 0.05) in Group 1, particularly thoracic infections. Another 56 (43%) cases were considered local pathogens, treated with drainage only or short-course antibiotics (Group 2). Another 38 (29%) cases were deemed commensals (Group 3). Immunosuppression was less frequent in Group 1 versus Group 2 or 3 ( P = 0.05) and human immunodeficiency virus or AIDS was uncommon. Foreign bodies or devices (Group 1 versus Group 2 or 3, P = 0.003) and alcoholism (Group 1 versus Group 2 or 3; P = 0.03) were associated with actinomycosis. Isolates from the central nervous system and musculoskeletal sites were more often treated as definitive disease; skin, abdominal or pelvic or single blood culture isolates were more likely commensals (all P < 0.05). Disease progression or recurrence did not occur in Groups 2 and 3, whereas Group 1 had complex and variable courses, including 2 deaths. Conclusions In the absence of disseminated or end-organ disease, avoiding prolonged therapy for Actinomyces isolates was not associated with adverse outcomes. Alcoholism or foreign bodies were associated with actinomycosis . A. meyeri may be a more common cause of actinomycosis than previously recognized.