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 urinary tract infection, 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 other sites. Thirty-four patients (55.7%) had a history of receiving intravenous antibiotics within 3 months of the diagnosis. Fifty-one (81.9%) cases involved polymicrobial infections. Extensive drug-resistant infections have been reported since 2018. The highest antibiotic sensitivity rate for Alcaligenes faecalis, 75%, was reported from 2018 to 2019. Ciprofloxacin, piperacillin/tazobactam, amikacin, and cefepime are not good choices for empiric therapy of Alcaligenes faecalis infection.Conclusions: The most frequent Alcaligenes faecalis infection sites were in the urinary tract, skin and soft tissue, and lung. Most cases were polymicrobial infections. Alcaligenes faecalis showed markedly deceasing sensitivity to commonly used antibiotics and, more recently, extensive drug-resistant Alcaligenes faecalis infections have emerged.