Microbiology of Species Isolated From Patients With Invasive Disease and Contaminated Samples in a Comprehensive Cancer Center.

BACKGROUND

are mucous membrane commensals that infrequently cause invasive disease. Our goal was to define species prevalence, the predominant disease site and risk factors for actinomycosis.

METHODS

We retrospectively reviewed patients with growth of species from cultures in a single-cancer center from July 2007 to June 2020. Proven invasive actinomycosis was defined as the presence of compatible clinical syndrome and radiographic findings with histopathological confirmation or culture from a normally sterile site. Probable invasive actinomycosis was defined based on the same criteria but without histologic confirmation. Contaminants were defined as culture growth in the absence of clinical or radiological findings consistent with disease. Speciation of was performed by the bioMerieux VITEK 2 anaerobic and coryneform identification card.

RESULTS

Of 235 patients, 179 (76.2%) had malignancy. Among 90 (38.3%) patients with invasive actinomycosis, was isolated in 32 (35.6%), followed by in 20 (22.2%), and in 17 (18.9%). Among 145 (61.7%) colonized patients, was isolated in 67 (46.2%), followed by in 27 (18.6%). Abdominopelvic infection was the most common site for invasive actinomycosis documented in 54 patients (60.0%) followed by orocervicofacial in 14 (15.6%) and thoracic in 10 (11.1%).

CONCLUSIONS

and were the most frequently isolated species causing invasive actinomycosis, and and among colonizers. Abdominopelvic represented the most frequent site for invasive disease. Further studies are needed to investigate the epidemiology of species in this population.