Antimicrobial susceptibility of Clostridium difficile isolates from ICU colonized patients revealed alert to ST-37 (RT 017) isolates

Seventy Clostridium difficile isolates from ICU colonized patients were tested for antimicrobial susceptibility and screened for resistance determinants. We found that multilocus sequence type 37 (ribotype 017) toxin A-negative/B-positive isolates were more likely resistant to moxifloxacin than toxin A-positive/B-positive isolates (41.7% versus 9.3%) with major variations in both GyrA (Thr82Ile) and GyrB (Ser366Ala), suggesting that the use of quinolone should be more strictly regulated.