Reduced Vancomycin Susceptibility Tied to Poorer C. Diff Outcomes

TUESDAY, April 30, 2024 (HealthDay News) — Reduced vancomycin susceptibility is impacting clinical responses among adults with Clostridioides difficile (C. difficile) infection, according to a study recently published in Clinical Infectious Diseases.

Taryn A. Eubank, Pharm.D., from the University of Houston College of Pharmacy, and colleagues examined if reduced vancomycin susceptibility is associated with decreased rates of sustained clinical response (SCR) among adults with C. difficile infection treated with oral vancomycin between 2016 and 2021.

The researchers found that 34 percent of C. difficile isolates showed reduced vancomycin susceptibility (range, 0.5 to 16 μg/mL; MIC_50/90 = 2/4 μg/mL). The highest proportion (77.4 percent) of isolates with reduced vancomycin susceptibility were ribotype 027. Overall, 30-day SCR was achieved by 83 percent of patients. There was an association between reduced vancomycin susceptibility and lower rates of 30-day SCR (76 percent) versus vancomycin-susceptible strains (86 percent). Similarly, the 14-day initial cure rate was significantly lower among individuals infected with strains with reduced vancomycin susceptibility (89 versus 96 percent). In multivariable modeling, reduced susceptibility remained an independent predictor of 30-day SCR (odds ratio, 0.52).

“It”s an alarming development in the field of C. diff as there are only two recommended antibiotics,” coauthor Kevin Garey, Pharm.D., also from the University of Houston, said in a statement. “If antimicrobial resistance increases in both antibiotics, it will complicate the management of C. diff infection leading us back to a pre-antibiotic era.”

Two authors disclosed ties to the pharmaceutical industry.

Abstract/Full Text (subscription or payment may be required)