Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, Australia.
The Department of Surgery - Otolaryngology Head and Neck Surgery, University of Adelaide and the Basil Hetzel Institute for Translational Health Research, Central Adelaide Local Health Network, Adelaide, Australia.
Microb Genom. 2023 Nov;9(11). doi: 10.1099/mgen.0.001128.
Chronic rhinosinusitis (CRS) is a common chronic sinonasal mucosal inflammation associated with biofilm and relapsing infections. This study aimed to determine rates of persistence and pathoadaptation in CRS patients by investigating the genomic relatedness and antibiotic resistance/tolerance in longitudinally collected clinical isolates. A total of 68 . paired isolates (34 pairs) were sourced from 34 CRS patients at least 6 months apart. Isolates were grown into 48 h biofilms and tested for tolerance to antibiotics. A hybrid sequencing strategy was used to obtain high-quality reference-grade assemblies of all isolates. Single nucleotide variants (SNV) divergence in the core genome and sequence type clustering were used to analyse the relatedness of the isolate pairs. Single nucleotide and structural genome variations, plasmid similarity, and plasmid copy numbers between pairs were examined. Our analysis revealed that 41 % (14/34 pairs) of isolates were persistent, while 59 % (20/34 pairs) were non-persistent. Persistent isolates showed episode-specific mutational changes over time with a bias towards events in genes involved in adhesion to the host and mobile genetic elements such as plasmids, prophages, and insertion sequences. Furthermore, a significant increase in the copy number of conserved plasmids of persistent strains was observed. This was accompanied by a significant increase in biofilm tolerance against all tested antibiotics, which was linked to a significant increase in biofilm biomass over time, indicating a potential biofilm pathoadaptive process in persistent isolates. In conclusion, our study provides important insights into the mutational changes during persistence in CRS patients highlighting potential pathoadaptive mechanisms in persistent isolates culminating in increased biofilm biomass.
慢性鼻-鼻窦炎（CRS）是一种常见的慢性鼻-鼻窦黏膜炎症，与生物膜和复发性感染有关。本研究旨在通过调查纵向收集的临床分离株的基因组相关性和抗生素耐药性/耐受性，确定 CRS 患者持续存在和适应病理的发生率。总共从至少相隔 6 个月的 34 名 CRS 患者中获得了 68 对（34 对）配对分离物。将分离物培养成 48 小时生物膜，并测试对抗生素的耐受性。使用混合测序策略获得所有分离物的高质量参考级装配体。核心基因组中的单核苷酸变异（SNV）分化和序列类型聚类用于分析分离物对的相关性。检查了配对之间的单核苷酸和结构基因组变异、质粒相似性和质粒拷贝数。我们的分析表明，41%（14/34 对）的分离物是持续存在的，而 59%（20/34 对）是非持续存在的。随着时间的推移，持续存在的分离物表现出特定于发作的突变变化，偏向于与宿主粘附和移动遗传元件（如质粒、噬菌体和插入序列）相关的基因中的事件。此外，还观察到持续菌株的保守质粒拷贝数显著增加。这伴随着对所有测试抗生素的生物膜耐受性显著增加，这与生物膜生物量随时间的显著增加有关，表明持续分离物中存在潜在的生物膜病理适应过程。总之，本研究提供了有关 CRS 患者持续存在期间突变变化的重要见解，突出了持续分离物中潜在的病理适应机制，最终导致生物膜生物量增加。
