Department of Clinical Laboratory, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, China.
School of Public Health, Jiangxi Medical College, Nanchang University, Nanchang, China.
Antimicrob Agents Chemother. 2024 Nov 6;68(11):e0075424. doi: 10.1128/aac.00754-24. Epub 2024 Oct 10.
Cefiderocol (FDC) is an effective antibiotic that is used to treat severe infections caused by carbapenem-resistant (CRKP). The mechanisms underlying FDC resistance and molecular epidemiology in China remain unclear. We collected 477 non-duplicate CRKP clinical isolates in central China and characterized their susceptibility to FDC, virulence genes, and sequence typing. The overall FDC susceptibility rate of CRKP was 99.2% in central China, which was higher than that in North America and Europe (96.1%), with MIC values of 1/2 mg/L. The decrease in FDC susceptibility in central China was concentrated in the ST11 CRKP-carrying virulence plasmids. Whole-genome sequencing (WGS) and quantitative reverse transcription PCR (qRT-PCR) experiments showed that serine β-lactamases, especially highly expressed KPC and SHV, substantially decreased FDC susceptibility in four FDC non-susceptible isolates (two resistant and two intermediate isolates). Notably, different CirA deficiencies, p.E450GfsTer16 and p.E133Ter, were found in both of the resistant isolates. In contrast, global WGS data indicate that the resistance mechanisms in North America and Europe were primarily associated with NDM and KPC variants, predominantly found in ST307 and ST147. Overall, FDC exhibits excellent activity against CRKP in central China, with resistance mechanisms primarily related to high KPC and SHV expression, along with deficiencies in CirA, frequently observed in ST11. This is remarkably different from the situation in North America and Europe and will directly impact the choice of clinical interventions. Additionally, the surveillance of FDC resistance in China is imperative.
头孢他啶-阿维巴坦(FDC)是一种有效的抗生素,用于治疗由耐碳青霉烯类肠杆菌科(CRKP)引起的严重感染。FDC 耐药的机制和中国的分子流行病学仍不清楚。我们收集了中国中部的 477 株非重复 CRKP 临床分离株,对其对 FDC 的敏感性、毒力基因和序列分型进行了特征描述。中国中部的 CRKP 对 FDC 的总体敏感性率为 99.2%,高于北美和欧洲(96.1%),MIC 值为 1/2mg/L。FDC 在中国中部的敏感性下降主要集中在携带毒力质粒的 ST11 CRKP 中。全基因组测序(WGS)和实时定量 RT-PCR(qRT-PCR)实验表明,丝氨酸β-内酰胺酶,尤其是高表达的 KPC 和 SHV,显著降低了 4 株 FDC 不敏感分离株(2 株耐药和 2 株中介分离株)对 FDC 的敏感性。值得注意的是,在这 2 株耐药分离株中发现了不同的 CirA 缺失,p.E450GfsTer16 和 p.E133Ter。相比之下,全球 WGS 数据表明,北美和欧洲的耐药机制主要与 NDM 和 KPC 变体相关,主要存在于 ST307 和 ST147 中。总的来说,FDC 对中国中部的 CRKP 表现出优异的活性,其耐药机制主要与高表达的 KPC 和 SHV 以及 CirA 缺失有关,这在 ST11 中经常发生。这与北美和欧洲的情况有显著不同,将直接影响临床干预措施的选择。此外,对中国 FDC 耐药性的监测是必要的。