Department of Medical Biotechnologies, University of Siena, Siena, Italy.
Present address: Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy.
Microb Genom. 2020 Jan;6(1). doi: 10.1099/mgen.0.000308.
In this work, we used a whole-genome sequencing (WGS) approach to study the features of KPC-producing (KPC-Kp) spreading in a large Italian long-term acute-care rehabilitation facility (LTACRF), and to track the dynamics of dissemination within this setting. Thirty-eight, non-replicated, KPC-Kp isolates from colonized patients (either already colonized at admission or colonized during admission), collected during 2016, were subjected to antimicrobial-susceptibility testing and WGS. All isolates were resistant to β-lactams, with the exception of ceftazidime/avibactam (97.4 % susceptible). The second most effective agent was fosfomycin, followed by colistin, trimethoprim/sulfamethoxazole, gentamicin and amikacin (92.1, 86.8, 60.5, 44.7 and 50 % of susceptibility, respectively). A large proportion of isolates (=18/38, 47.4%) belonged to clonal group (CG) 101, and most of them (=15) to a new sequence type (ST) designated as ST2502. All the CG101 isolates had a capsule locus type KL17. The ST2502 harboured the genes encoding for the yersiniabactin siderophore and the ArmA methylase, conferring high-level resistance to aminoglycosides. The second most represented lineage of isolates (16/38, 42.1%) belonged to ST512 of CG258. Analysing WGS data, we were able to ascertain the common origin of some isolates imported from other hospitals, and to track several clusters of in-LTACRF cross-transmissions. The results revealed that, in peculiar epidemiological settings such as LTACRF, new KPC-Kp clones different from those prevailing in acute-care hospitals and associated with uncommon resistance and virulence determinants can successfully emerge and disseminate.
在这项工作中，我们使用全基因组测序 (WGS) 方法研究了在意大利一家大型长期急性护理康复机构 (LTACRF) 中传播的产 KPC (KPC-Kp) 的特征，并追踪了该环境中传播的动态。2016 年，从定植患者（入院时已定植或住院期间定植）中采集了 38 个非复制的 KPC-Kp 分离株，进行了抗菌药物敏感性测试和 WGS。所有分离株均对β-内酰胺类药物耐药，除头孢他啶/阿维巴坦（97.4%敏感）外。第二有效的药物是磷霉素，其次是黏菌素、复方磺胺甲噁唑、庆大霉素和阿米卡星（分别为 92.1%、86.8%、60.5%、44.7%和 50%的敏感性）。很大一部分分离株（=18/38，47.4%）属于克隆群（CG）101，其中大多数（=15）属于新的序列类型（ST），命名为 ST2502。所有 CG101 分离株均具有 KL17 荚膜基因座类型。ST2502 携带编码耶尔森菌铁载体和 ArmA 甲基化酶的基因，对氨基糖苷类药物具有高水平耐药性。第二大代表分离株谱系（16/38，42.1%）属于 CG258 的 ST512。分析 WGS 数据，我们能够确定从其他医院输入的一些分离株的共同来源，并追踪 LTACRF 内的几个交叉传播群。结果表明，在 LTACRF 等特殊流行病学环境中，不同于急性护理医院流行的新型 KPC-Kp 克隆，并带有罕见的耐药性和毒力决定因素，可成功出现并传播。
