Changes in Clostridium (Clostridioides) difficile PCR-Ribotype Distribution and Antimicrobial Resistance in a German Tertiary Care Hospital Over the Last 10 Years.

ABSTRACT

Clostridium (Clostridioides) difficile ribotype 027 (RT027) was detected in Germany for the first time in 2007 during an outbreak in the region of Trier, Rhineland-Palatinate and is today the most prevalent ribotype (RT) in Europe. We aimed to determine the changes in RT distribution and corresponding antimicrobial resistance in clinical C. difficile isolates between two time points (2007 and 2017) in one tertiary care hospital in Germany. C. difficile isolates recovered in 2007 and in 2017 (80 isolates per year, respectively) from patients at a Tertiary Care University Hospital in North-Rhine Westphalia were analyzed. Isolates were characterized by ribotyping and susceptibility testing using gradient tests (metronidazole, vancomycin) and the disk diffusion method (moxifloxacin). Between 2007 and 2017, a clear switch from RT001 [18.75% (n = 15) in 2007 versus 3.75% (n = 3) in 2017 P = 0.003] to RT027 [0% in 2007 versus 21.25% (n = 17) in 2017] was evident. While minimal inhibitory concentrations (MICs) of vancomycin were stable, a significant metronidazole MIC creep was determined (MIC50 = 0.047 in 2007 versus MIC50 = 0.094 in 2017, P < 0.0001 using the Man-Whitney test). We detected one metronidazole-resistant isolate (0.6%). Interestingly, in total we encountered more isolates resistant to moxifloxacin in 2007 (42 (52.25%) than in 2017 [(30 (37.5%), P = 0.06)]). We could demonstrate that RT027 replaced RT001 in the last 10 years in our hospital. Furthermore, our data show a metronidazole MIC creep in C. difficile isolates over the last 10 years and an unexpected decrease of isolates resistant to moxifloxacin.