P-94. Can Fluoroquinolones Be Used for the Treatment of Deep-Seated <i>Streptococcus anginosus</i> group Infections?

Abstract Background Invasive infections caused by Streptococcus anginosus group are increasingly common. Some experts recommend against treatment with fluoroquinolone (FQs) dues to potential development of fluoroquinolone resistance; however, this is not based on clinical data. The aim of this study is to compare the safety and effectiveness of FQ-based antibiotic regimens with non-FQ regimens for the treatment of deep-seated S. anginosus group infections. Methods This was a retrospective cohort study of patients hospitalized at Denver Health Medical center between 4/1/2016 and 10/31/2023 with a deep-seated infection and isolation of S. anginosus group from tissue, bone, synovial or pleural fluid. Cases were categorized as having been treated with a fluoroquinolone as part of their antibiotic regimen or not. The primary outcome was treatment success at 90 days as defined as absence of the following: recurrent infection, need for repeat surgical intervention or hospital readmission related to the primary infection. Secondary outcomes included antibiotic-related adverse events and central venous catheter complications. Results 144 cases of deep-seated infection involving a S. anginosus group were identified; 69 received a FQ while 75 were treated with other antibiotics. Those in the FQ group were more likely to discharge on oral antibiotics (64 [93%] vs. 40 [53%], p&amp;lt; .001) and had a shorter duration of intravenous therapy (2 days vs. 13 days, p&amp;lt; .001). Treatment success occurred in 62 (90%) patients in the FQ group and 69 (92%) patients in the non-FQ group (p=0.65). Rates of antibiotic-related adverse events and vascular complications were similar between groups. Of patients who received a FQ, no patients had treatment failure or recurrent infection with an isolate resistant to a FQ. Conclusion FQs appeared to be a safe and effective treatment option for deep-seated S. anginosus group infections and facilitated early transition to oral therapy, while the development of FQ resistance was not observed. Disclosures All Authors: No reported disclosures