title: In vitro activity of MCB3681 against Clostridium difficile strains.
abstract: One hundred fourteen Clostridium difficile strains were collected from 67 patients and analyzed for the presence of C. difficile toxin B by the cell cytotoxoicity neutralization assay, genes for toxin A, toxin B, binary toxin and TcdC deletion by PCR. All strains were also PCR-ribotyped. The MICs of the isolates were determined against MCB3681 and nine other antimicrobial agents by the agar dilution method. All isolates were positive for toxin B as well as for toxin A and B genes. In addition, 13 isolates were positive for the binary toxin genes. Thirty-two different ribotypes were identified. No strain of ribotype 027 was found. All 114 isolates were sensitive to MCB3681 (0.008-0.5 mg/l), cadazolid (0.064-0.5 mg/l), fidaxomicin (0.008-0.125 mg/l), metronidazole (0.125-2 mg/l), vancomycin (0.125-1 mg/l) and tigecycline (0.032-0.25 mg/l). Three isolates were resistant to linezolid (8 mg/l), 12 isolates were resistant to moxifloxacin (8-32 mg/l), 87 isolates were resistant to clindamycin (8-256 mg/l) and 107 isolates were resistant to ciprofloxacin (8-256 mg/l). No association between toxins A, B and binary toxin, ribotypes and the sensitivity to MCB3681 could be found. MCB3681 has a potent in vitro activity against C. difficile.
authors.affiliation: Department of Laboratory Medicine, Karolinska University Hospital, Karolinska Institutet, SE-141 86 Stockholm, Sweden.
authors.forename: Mamun-Ur
authors.initials: MU
authors.lastname: Rashid
authors.affiliation: University Medical Center Schleswig-Holstein, Institute for Infection Medicine, Brunswiker Str. 4, D-24105 Kiel, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Dalhoff
authors.affiliation: Department of Laboratory Medicine, Karolinska University Hospital, Karolinska Institutet, SE-141 86 Stockholm, Sweden.
authors.forename: Andrej
authors.initials: A
authors.lastname: Weintraub
authors.affiliation: Department of Laboratory Medicine, Karolinska University Hospital, Karolinska Institutet, SE-141 86 Stockholm, Sweden. Electronic address: carl.erik.nord@ki.se.
authors.forename: Carl Erik
authors.initials: CE
authors.lastname: Nord
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001427:Bacterial Toxins / Q000032:analysis / Q000235:genetics; D016360:Clostridioides difficile / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D003015:Clostridium Infections / Q000382:microbiology; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D021521:Ribotyping; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins
keywords: Clostridium difficile infections; In vitro activity; MCB3681, MCB3837