Houston, We Have a Problem: Reports of Clostridioides difficile Isolates With Reduced Vancomycin Susceptibility

During the past 4 decades, oral vancomycin has been a mainstay of Clostridioides difficile infection (CDI) therapy with no reports of treatment failure due to emergence of vancomycin resistance. However, C. difficile isolates with high-level phenotypic resistance to vancomycin have recently been reported in 3 distinct geographic regions. There is an urgent need for surveillance to determine if strains with reduced vancomycin susceptibility are circulating in other areas. In a Cleveland-area hospital, screening of 176 CDI stool specimens yielded no C. difficile isolates with reduced vancomycin susceptibility and highlighted the potential for false-positive results due to contamination with vancomycin-resistant enterococci. Additional studies are needed to clarify whether reduced vancomycin susceptibility is an emerging problem that will alter clinical practice. Clinicians should alert their health department if they observe a substantial increase in the frequency of vancomycin treatment failure in patients diagnosed with CDI with no alternative explanation for diarrhea.