An investigation into breast infections caused by Actinomyces species.

We investigated the management of Actinomyces breast infection. Eight different Actinomyces species were isolated from 26 patients during the study period (December 2018-November 2021). All tested isolates were susceptible (at standard or high dose) to penicillin and 75 % to clindamycin. Twenty-three patients had a history of smoking. Three had coexisting breast cancer. Prescribers need to be educated about the lack of activity of metronidazole on Actinomyces.