2662. Efficacy of Sitafloxacin and Doxycycline Combination Therapy as a Salvage Treatment for Refractory Mycoplasma genitalium Infection

BACKGROUND: The prevalence of resistant strains of Mycoplasma genitalium has increased over the past few decades, leading to limited treatment options. This study aimed to evaluate the efficacy of sitafloxacin and doxycycline combination therapy as a salvage treatment for refractory rectal and urogenital M. genitalium infections. METHODS: Men who have sex with men (MSM) diagnosed to have M. genitalium infection from urine samples or rectal swabs using a PCR assay were evaluated and administered sitafloxacin 200 mg and doxycycline 200 mg daily for 21 days. Each sample was tested for 23rRNA, parC, and gyrA mutations before and if a failure after the treatment. RESULTS: A total of 27 MSMs were included. The median age was 33 years (range 21-47), and 33.3% (9/27) were people with HIV(PWH) (Table). Among PWH, the median CD4 count was 642, and all were virally suppressed with antiretroviral therapy. Positive samples included 22 rectal and 5 urine specimens. The time to test of cure(TOC) was 14 days (range 0-227). In the two failure cases 9 and 20, the TOC was conducted too early, and it was rechecked after 21 days following treatment completion; both rechecked TOCs were positive. ParC mutations were detected in 100%(23/23) of the samples, gyrA mutations in 66.7%(16/24) and ,macrolide-resistance associated mutations in 100%(22/22). Among the parC mutations, 95.7%(22/23) was G248T(S83I), while 4.3%(1/23) was G259T(D87Y). The overall cure rate was 81.5%. The cure for rectal infection was 81.8%(18/22), while the cure rate for urogenital infection was 80%(4/5). No significant difference was observed between the anatomical sites (p=0.924). The cure rate for strains harboring parC mutation and wild-type in gyrA was 85.7% (6/7), whereas the cure rate for the strain harboring parC mutation and gyrA mutation was 73.3%(11/15). No significant difference was found regardless of gyrA mutations (p=0.519). Additionally, no significant difference was observed in the cure rate between TOC < 21 days and >= 21 days (p=0.964). Cases of Mycoplasma genitalium treatment and antimicrobial-resistance profiles in participants before and after treatment with the combination therapy [Figure: see text] CONCLUSION: The combination therapy showed high efficacy of 81.5% for highly resistant M. genitalium infection and can be considered as a salvage treatment option for refractory cases. DISCLOSURES: All Authors: No reported disclosures