Highly antibiotic‐resistant Clostridium difficile isolates from Iranian patients

• Published in: Journal of applied microbiology 2018-11, Vol.125 (5), p.1518-1525
• Main Authors: Baghani, A., Ghourchian, S., Aliramezani, A., Yaseri, M., Mesdaghinia, A., Douraghi, M.
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; Anti-Infective Agents - pharmacology; Antibiotic resistance; antibiotic susceptibility testing; Antibiotics; Bacteria; Bacteriology; Breakpoints; Ciprofloxacin; Ciprofloxacin - pharmacology; Clostridium difficile; Clostridium difficile - drug effects; Clostridium difficile - isolation & purification; Clostridium difficile - pathogenicity; Clostridium Infections - drug therapy; Clostridium Infections - microbiology; disc diffusion; Drug Resistance, Multiple, Bacterial; Fluoroquinolones; Fluoroquinolones - pharmacology; Humans; Iran; Metronidazole; Metronidazole - pharmacology; MIC Test Strips; Microbial Sensitivity Tests; Minimum inhibitory concentration; Moxifloxacin; Patients; Phenotypes; resistance; Vancomycin; Vancomycin - pharmacology
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/jam.14035

Aims Little is known about the resistance rate and susceptibility profile of Clostridium difficile isolates in Iran. Therefore, the aim of present study is to assess the rate of drug‐resistant C. difficile. Methods and Results During a 6‐year period, four hospitals submitted 735 stool specimens from patients suspected for C. difficile infections to the anaerobic bacteriology laboratory. The 46 C. difficile isolates were subjected to disc diffusion and minimum inhibitory concentration (MIC) Test Strips. All isolates were susceptible to vancomycin (VAN) while the highly resistant phenotypes of metronidazole (MTZ) (67·4%), moxifloxacin (78·3%), ciprofloxacin (69·5%) and tetracycline (82·6%) were observed. Of more concern, 67·3% of C. difficile isolates displayed multidrug‐resistant phenotypes. More than half of the isolates (n = 27, 58·6%) were coresistant to ciprofloxacin and moxifloxacin. The MIC90 of VAN was ≤2 mg l−1, whereas this value for MTZ, ciprofloxacin, moxifloxacin and tetracycline was higher than the resistance breakpoints. According to the comparison of interpretive categories for two tests, the categorical agreement was less than 90% for VAN, ciprofloxacin and tetracycline. Conclusions The disc diffusion method can be used to detect the isolates with reduced susceptibility to MTZ or moxifloxacin. The high rate of resistance to fluoroquinolones highlights the possibility of the emergence of hypervirulent strains in our settings. Significance and Impact of the Study This study provides data regarding the high level of resistance against multiple antibiotics except VAN.