Extensively drug-resistant Alcaligenes faecalis infection

Abstract

Background: Alcaligenes faecalis is usually opportunistic infection in humans. Alcaligenes faecalis infection is often challenging to treat due to its increased resistance to many antibiotics. The results from a clinical study of Alcaligenes faecalis infection may help improve patients’ clinical care. Methods: We conducted a retrospective analysis of all patients presenting with Alcaligenes faecalis infection from January 2014 through December 2019. The medical records of all patients were reviewed for demographic information, clinical symptoms and signs, comorbidities, use of intravenous antibiotics within the past 3 months, bacterial culture, antibiotics sensitivity test, and clinical outcomes. Results: Sixty-one cases of Alcaligenes faecalis infection were seen during the study period, including 25 cases of cystitis, 9 cases of diabetic foot ulcer with infection, 8 cases of pneumonia, 7 cases of acute pyelonephritis, 3 cases of bacteremia, 9 cases of infection at specific sites. Thirty-seven patients (60.7%) had a history of receiving intravenous antibiotics within 3 months of the diagnosis. Fifty-one (83.6%) cases were mixed with other bacterial infections. Extensively drug-resistant infections have been reported since 2018. The best sensitivity rate to A. faecalis was 66.7% for three antibiotics (imipenem, meropenem, and ceftazidime) in 2019. Two antibiotics (ciprofloxacin and piperacillin/tazobactam) sensitivity rates to A. faecalis were less than 50%. Conclusions: The most frequent Alcaligenes faecalis infection sites were in the bloodstream, urinary tract, skin and soft tissue, and middle ear. Alcaligenes faecalis showed markedly decreased sensitivity to commonly used antibiotics and, more recently, extensively drug-resistant Alcaligenes faecalis infections have emerged.