Izydorczyk Conrad, Waddell Barbara, Edwards Brett D, Greysson-Wong Jasper, Surette Michael G, Somayaji Ranjani, Rabin Harvey R, Conly John M, Church Deirdre L, Parkins Michael D
Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
Front Microbiol. 2020 Mar 20;11:475. doi: 10.3389/fmicb.2020.00475. eCollection 2020.
is frequently isolated from the respiratory secretions of cystic fibrosis (CF) patients yet is not considered a classical CF pathogen. Accordingly, little is known about the natural history of this organism in the CF airways, as well as the potential for patient-to-patient transmission. Patients attending the Calgary Adult CF Clinic (CACFC) between January 1983 and December 2016 with at least one -positive sputum culture were identified by retrospective review. Annual isolates from the CACFC biobank from each patient were typed by pulsed-field gel electrophoresis (PFGE) and isolates belonging to shared pulsotypes were sequenced. Single nucleotide polymorphism (SNP) and phylogenetic analysis were used to investigate the natural history of infection and identify potential transmission events. Forty-five patients with -positive sputum cultures were identified. Most patients had a single infection episode with a single pulsotype, while replacement of an initial pulsotype with a second was observed in three patients. Twenty-four had recovered from their sputum more than once and 18 patients had persistent infections ( carriage >6 months with ≥3 positive cultures). Shared pulsotypes corresponded to known extraintestinal pathogenic strains: ST-131, ST-73, and ST-1193. Phylogenetic relationships and SNP distances among isolates within shared pulsotypes were consistent with independent acquisition of by individual patients. Most recent common ancestor date estimates of isolates between patients were inconsistent with patient-to-patient transmission. infection in CF is a dynamic process that appears to be characterized by independent acquisition within our patient population and carriage of unique sets of strains over time by individual patients.
该菌经常从囊性纤维化（CF）患者的呼吸道分泌物中分离出来，但不被认为是典型的CF病原体。因此，关于这种微生物在CF气道中的自然史以及患者之间传播的可能性知之甚少。通过回顾性研究确定了1983年1月至2016年12月期间在卡尔加里成人CF诊所（CACFC）就诊且至少有一次痰培养呈阳性的患者。对来自每个患者的CACFC生物样本库的年度分离株进行脉冲场凝胶电泳（PFGE）分型，并对属于共享脉冲型的分离株进行测序。使用单核苷酸多态性（SNP）和系统发育分析来研究感染的自然史并识别潜在的传播事件。确定了45例痰培养呈阳性的患者。大多数患者有单一脉冲型的单次感染发作，而在3例患者中观察到初始脉冲型被第二种替代。24例患者痰中多次检出该菌，18例患者有持续性感染（携带>6个月且≥3次阳性培养）。共享脉冲型对应于已知的肠外致病性菌株：ST-131、ST-73和ST-1193。共享脉冲型内分离株之间的系统发育关系和SNP距离与个体患者独立获得该菌一致。患者之间分离株的最近共同祖先日期估计与患者之间的传播不一致。CF中的感染是一个动态过程，其特征似乎是在我们的患者群体中独立获得，并且个体患者随时间携带独特的菌株组合。
