Division of Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
J Appl Microbiol. 2018 Nov;125(5):1518-1525. doi: 10.1111/jam.14035. Epub 2018 Aug 20.
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.
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 , 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.
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.
This study provides data regarding the high level of resistance against multiple antibiotics except VAN.
关于伊朗艰难梭菌分离株的耐药率和药敏谱知之甚少。因此，本研究旨在评估耐药艰难梭菌的发生率。
在 6 年期间，四家医院将 735 份来自疑似艰难梭菌感染患者的粪便标本提交给厌氧细菌学实验室。46 株艰难梭菌分离株进行了药敏纸片扩散法和最低抑菌浓度（MIC）测试条检测。所有分离株均对万古霉素（VAN）敏感，而甲硝唑（MTZ）（67.4%）、莫西沙星（78.3%）、环丙沙星（69.5%）和四环素（82.6%）的高度耐药表型被观察到。更令人担忧的是，67.3%的艰难梭菌分离株表现出多药耐药表型。超过一半的分离株（n=27，58.6%）对环丙沙星和莫西沙星表现出协同耐药。VAN 的 MIC90≤2mg/L，而 MTZ、环丙沙星、莫西沙星和四环素的 MIC90 值均高于耐药折点。根据两种检测方法的解释类别比较，VAN、环丙沙星和四环素的分类一致性低于 90%。
药敏纸片扩散法可用于检测对 MTZ 或莫西沙星敏感性降低的分离株。氟喹诺酮类药物的高耐药率突显了我们环境中出现高毒力菌株的可能性。
本研究提供了除 VAN 外，对多种抗生素高度耐药的数据。
