Antibiotic Selection and Outcomes in Patients With Monomicrobial and Polymicrobial Vibrio Necrotizing Fasciitis.

BACKGROUND: Necrotizing fasciitis (NF) caused by Vibrio species is a rapidly progressing, life-threatening infection. The purposes of this study were to characterize polymicrobial Vibrio NF and compare its clinical features, microbiology, antimicrobial therapy, and outcomes with those of monomicrobial Vibrio NF, and to evaluate the effective usage of empirical antibiotics. METHODS: One hundred and ninety-four patients surgically confirmed with Vibrio NF were retrospectively reviewed, in which 180 (92.8%) patients were infected by Vibrio vulnificus. There were 179 patients (92.3%) with a monomicrobial infection and 15 (7.7%) with polymicrobial infections. Clinical characteristics, outcomes, laboratory data, and antibiotic usage were analyzed and compared between the two groups. RESULTS: Twenty-nine patients with Vibrio NF died (14.9%). Mortality was 15.6% (28/179) in the monomicrobial group and 6.7% (1/15) in the polymicrobial group. Among the 15 polymicrobial cases, 14 were caused by Vibrio vulnificus and 1 by Vibrio parahaemolyticus. Gout was more frequently observed in the polymicrobial group (4/15) than in the monomicrobial group (11/179). Vibrio isolates showed high susceptibility to third-generation cephalosporins, fluoroquinolones, and tetracyclines. Effective antimicrobial therapy was associated with lower mortality (p = 0.002) and lower amputation rates (p = 0.004). CONCLUSIONS: Polymicrobial Vibrio NF was uncommon but was not clinically less severe than monomicrobial Vibrio NF in this 20-year cohort. Patients with polymicrobial infection more frequently had gout, suggesting a potential clinical association that warrants further investigation. These findings indicate that suspected polymicrobial Vibrio NF should be treated with the same urgency as monomicrobial disease, with prompt surgery, intensive care, and empirical antimicrobial therapy covering both Vibrio species and relevant copathogens.