Healthcare-Associated Infections Research Group, Molecular Gastroenterology, Leeds Institute for Biomedical and Clinical Sciences, University of Leeds, Old Medical School, Leeds General Infirmary, LS1 3EX, West Yorkshire, UK.
Healthcare-Associated Infections Research Group, Molecular Gastroenterology, Leeds Institute for Biomedical and Clinical Sciences, University of Leeds, Old Medical School, Leeds General Infirmary, LS1 3EX, West Yorkshire, UK; Microbiology, Leeds Teaching Hospitals Trust, Leeds, UK.
Anaerobe. 2021 Aug;70:102385. doi: 10.1016/j.anaerobe.2021.102385. Epub 2021 May 25.
Clostridioides difficile (CD) is widely reported as one of the most prevalent multi-drug resistant (MDR) organisms. Assessment of temporally disparate isolate collections can give valuable epidemiological data to further the understanding of antimicrobial resistance progression.
A collection of 75 CD isolates (1980-86) was characterised by PCR ribotyping, cell cytotoxicity assay and susceptibility testing with a panel of 16 antimicrobials and compared to a modern surveillance collection consisting of 416 UK isolates (2012-2016). Agar-incorporation was performed to ascertain susceptibility data for vancomycin, metronidazole, rifampicin, fidaxomicin, moxifloxacin, clindamycin, imipenem, chloramphenicol, tigecycline, linezolid, ciprofloxacin, piperacillin/tazobactam, ceftriaxone, amoxicillin, tetracycline and erythromycin. Genomes were obtained using Illumina HiSeq3000 sequencing and assembled using CLC Genomics Workbench. Resistance genes were identified using the Comprehensive Antibiotic Research Database's Resistance Gene Identifier and ResFinder3.0.
Twenty-six known and one previously unobserved ribotype (RT) were detected. RT015 and RT020 dominated; 21.3% and 17.3%, respectively. Three moxifloxacin resistant (16-32 mg/L) RT027 isolates were recovered, pre-dating the earliest reports of this phenotype/genotype. Phenotypic resistance was observed to moxifloxacin (9.3% of isolates), ciprofloxacin (100%), erythromycin (17.3%), tetracycline (9.3%), linezolid and chloramphenicol (4.0%). Phenotypic comparisons with modern strains revealed increasing minimum inhibitory concentrations (MIC), with MIC elevations of one doubling-dilution for the majority of compounds, excluding clindamycin and imipenem. Moxifloxacin MIC comparisons revealed a two doubling-dilution increase between temporal isolate collections. Historical genomes revealed twenty different resistance determinants, including ermB (8.0% of isolates), tetM (9.3%), cfr (5.3%) and gyrA substitution Thr-82→Ile (9.3%). Seventeen isolates (22.7%) were resistant to ≥3 compounds (MDR), demonstrating ten different combinations. Intra-RT diversity was observed.
Antibiotic resistance in CD has increased since the early 1980s, across the majority of classes. Moxifloxacin resistance determinants may pre-date its introduction.
艰难梭菌（CD）被广泛报道为最普遍的多药耐药（MDR）病原体之一。评估时间上不同的分离株集，可提供有价值的流行病学数据，以进一步了解抗微生物药物耐药性的进展。
对 75 株 CD 分离株（1980-86 年）进行了 PCR 核糖体分型、细胞细胞毒性测定和 16 种抗菌药物的药敏试验，并与 416 株英国分离株（2012-2016 年）的现代监测集进行了比较。进行琼脂掺入以确定万古霉素、甲硝唑、利福平、非达霉素、莫西沙星、克林霉素、亚胺培南、氯霉素、替加环素、利奈唑胺、环丙沙星、哌拉西林/他唑巴坦、头孢曲松、阿莫西林、四环素和红霉素的药敏数据。使用 Illumina HiSeq3000 测序获得基因组，并使用 CLC Genomics Workbench 进行组装。使用综合抗生素研究数据库的耐药基因标识符和 ResFinder3.0 鉴定耐药基因。
检测到 26 种已知和 1 种以前未观察到的核糖体类型（RT）。RT015 和 RT020 占主导地位；分别为 21.3%和 17.3%。从最早报告这种表型/基因型之前，就已经恢复了 3 株耐莫西沙星（16-32 mg/L）的 RT027 分离株。观察到莫西沙星（9.3%的分离株）、环丙沙星（100%）、红霉素（17.3%）、四环素（9.3%）、利奈唑胺和氯霉素（4.0%）的表型耐药。与现代菌株的表型比较显示，大多数化合物的最低抑菌浓度（MIC）升高了一个二倍稀释度，克林霉素和亚胺培南除外。莫西沙星 MIC 比较显示，两个时间分离株集之间 MIC 升高了两个二倍稀释度。历史基因组显示了 20 种不同的耐药决定因素，包括 ermB（8.0%的分离株）、tetM（9.3%）、cfr（5.3%）和 gyrA 取代 Thr-82→Ile（9.3%）。17 株（22.7%）对≥3 种化合物（MDR）耐药，表现出 10 种不同的组合。在 RT 内观察到多样性。
自 20 世纪 80 年代初以来，艰难梭菌的抗生素耐药性已经增加，涉及大多数类别。莫西沙星耐药决定因素可能早于其引入。
