DOI: 10.1093/bjs/znad258.571 ISSN:

408 Actinomyces Species Microbiology Proven Infection – an Increasingly Recognised Emerging Implicated Pathogen: An Observational Study

J Kiang, S Venkatesha, A Sanghera, N Raja, J Ahmed, A Ayantunde
  • Surgery



Actinomyces species, gram-positive filamentous anaerobic microaerophilic organisms, are commensals of the human oropharynx, gastrointestinal and urogenital tracts. Actinomycosis infection is rare and occurs when tissue integrity is compromised, typically in a polymicrobial fashion. There is an emerging rise in Actinomyces species associated infections with their therapeutic challenges.


To evaluate the pattern, presentation, and risk factors of Actinomyces species associated infections.


Blood culture, tissue, fluids, bone, and swab samples with isolated Actinomyces species were evaluated between July 2016 and April 2021. The antibiotic susceptibility of the isolated Actinomyces was obtained as per EUCAST guidelines. Electronic medical records were retrospectively evaluated for demographic and clinicopathological data relating to the patients.


145 patients were evaluated. The mean age was 49 years, 63 males and 82 females. 52.4% and 59.3% had co-morbidities and risk factors for Actinomyces species infection susceptibility respectively. The most common presentations were infected sebaceous cysts (25.5%) and pilonidal abscess (11.7%). Actinomyces species were isolated from swabs (78), pus(32), blood cultures(26), body fluids(6), soft tissues(2) and bone fragments(1). Eleven different Actinomyces species were isolated. The commonly isolated species were Actinomyces neuii(24.8%), Actinomyces turicensis(22.8%) and Actinomyces europaeus(13.8%). 57.2% of samples had mixed microorganisms isolated. 26/29 blood culture samples yielded Actinomyces and 6/29 yielded mixed microbial agents. 78.6% of patient received empirical antibiotics and 79% of antibiotic choice was appropriate.


Actinomyces species isolates, and infections are increasingly reported, potentially attributed to improved culture techniques. We recommend epidemiology and resistance surveillance in Actinomyces species associated infections.

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