Clostridioides Difficile National Reference Laboratory, Public Health Laboratory, Health Service Executive, Cherry Orchard Hospital, Dublin, Ireland; European Public Health Microbiology Training Programme (EUPHEM), European Centre for Disease Prevention and Control, Stockholm, Sweden.
Clostridioides Difficile National Reference Laboratory, Public Health Laboratory, Health Service Executive, Cherry Orchard Hospital, Dublin, Ireland; European Public Health Microbiology Training Programme (EUPHEM), European Centre for Disease Prevention and Control, Stockholm, Sweden.
Anaerobe. 2024 Aug;88:102857. doi: 10.1016/j.anaerobe.2024.102857. Epub 2024 Apr 25.
Infection with Clostridioides difficile usually occurs after antibiotic treatment for other infections and can cause gastro-intestinal disorders of variable severity. C. difficile can be resistant to a wide spectrum of antimicrobials. Detection of antimicrobial resistance (AMR) is important to direct optimal treatment and surveillance of AMR patterns in the overall population. Correlation between genotypic markers and phenotypic AMR is not yet well defined. The aim for this study is to assess whether and to what extent genotypic determinants of AMR correlate with phenotypic resistance.
C. difficile isolates (n = 99) were phenotypically characterized for resistance to eight antibiotics using Sensititre plates or E-tests. Their genomes were screened for genetic markers of resistance. Accuracy, sensitivity, specificity, positive and negative predictive values were calculated.
We found high rates of resistance (>50 %) to cefoxitin and clindamycin, intermediate rates of resistance (10 %-50 %) to moxifloxacin and tetracycline and low rates of resistance (<10 %) to imipenem, metronidazole, vancomycin, and rifampicin. For moxifloxacin, tetracycline, and clindamycin, we found a good correlation between genotypic and phenotypic AMR, with an overall accuracy of 98 % (95 % CI 93%-100 %), 78 % (95 % CI 68%-86 %) and 86 % (95 % CI 77%-92 %) respectively. For the other five antibiotics, accurate estimates on the correlation could not be made.
Our results suggest that for moxifloxacin, tetracycline and clindamycin, phenotypic resistance in C. difficile can be predicted by genetic indicators and used for public health purposes. However, for the other five antibiotics, the model is not accurate and further development is necessary.
艰难梭菌感染通常发生在其他感染的抗生素治疗后，可引起严重程度不同的胃肠疾病。艰难梭菌可能对抗生素具有广泛的耐药性。检测抗生素耐药性（AMR）对于指导最佳治疗和监测人群中的 AMR 模式非常重要。基因型标志物与表型 AMR 的相关性尚未明确。本研究旨在评估基因型决定因素与表型耐药性之间是否存在相关性，以及相关性的程度如何。
使用 Sensititre 板或 E 试验对 99 株艰难梭菌分离株进行了对 8 种抗生素的表型耐药性特征分析。对其基因组进行了耐药基因标记的筛选。计算了准确性、敏感性、特异性、阳性预测值和阴性预测值。
我们发现，对头孢西丁和克林霉素的耐药率（>50%）较高，对莫西沙星和四环素的耐药率（10%-50%）中等，对亚胺培南、甲硝唑、万古霉素和利福平的耐药率（<10%）较低。对于莫西沙星、四环素和克林霉素，我们发现基因型和表型 AMR 之间存在良好的相关性，总体准确性分别为 98%（95%CI 93%-100%）、78%（95%CI 68%-86%）和 86%（95%CI 77%-92%）。对于其他五种抗生素，无法准确估计相关性。
我们的结果表明，对于莫西沙星、四环素和克林霉素，艰难梭菌的表型耐药性可以通过遗传指标预测，并用于公共卫生目的。然而，对于其他五种抗生素，该模型并不准确，需要进一步开发。
