Department of Infectious Diseases and Clinical Microbiology, İstanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine, İstanbul, Türkiye
Microbiology Laboratory Unit, Malatya Training and Research Hospital, Malatya, Türkiye
Balkan Med J. 2024 Sep 6;41(5):357-368. doi: 10.4274/balkanmedj.galenos.2024.2024-5-99. Epub 2024 Aug 29.
Emerging carbapenem-resistant () (CRKP) bacteremias are presenting significant public health risks due to limited treatment options and increased mortality. isolates exhibit carbapenem resistance rates that vary from 25% to 50% throughout the European continent, including our country.
To assess the characteristics of CRKP bacteremia, a condition that has recently demonstrated an increasing prevalence in our center. We sought to ascertain the resistance rates of isolated strains to antibiotics other than carbapenems, identify the responsible carbapenemase genes, evaluate the efficacy of antibiotics, determine mortality rates, explore clonality among strains, and investigate the influence of the COVID-19 pandemic on all these factors.
Retrospective observational study.
This study included patients aged 18 and older who had experienced meropenem-resistant bacteremia. Meropenem resistance was confirmed by employing the Kirby-Bauer disk diffusion method. Meropenem minimum inhibitory concentration (MIC) levels were determined using the gradient test, while colistin MIC levels were ascertained using the disk elution technique. Carbapenemase genes were evaluated via colony polymerase chain reaction (PCR), and clonality analysis was performed using the arbitrarily primed PCR technique.
The study comprised 230 patients, with a mean age of 63.1 ± 15.9 years, of whom 58.7% were male. Oxacillinase-48 (OXA-48) was detected in 74.8% of the patients, New Delhi metallo-beta-lactamase (NDM) in 12.6%, OXA-48 + NDM in 7.8%, and KPC in 4.8%. The 14-day and 30-day mortality rates were 57% and 69.6%, respectively. Multivariate analysis of the 30-day mortality revealed several crucial factors, including bacteremia development in the intensive care unit, the occurrence of bacteremia during the COVID-19 pandemic, polymicrobial bacteremia, the use of indwelling intravenous catheters, a platelet count of ≤ 140,000/μl, procalcitonin levels of ≥ 6 μg/l, and a Charlson comorbidity score ≥ 3. Notably, the and genes were upregulated significantly during the COVID-19 pandemic, while the gene groups were downregulated. Additionally, both 14-day and 30-day mortality rates increased significantly.
In this study, the most prevalent carbapenemase gene was OXA-48; however, there has been a recent increase in genes. No dominant epidemic strain was identified through clonality analysis. The clustering rate was 68% before the pandemic, increasing to 85.7% during the pandemic. The significance of infection control measures is underscored by the rise in both clustering and mortality rates during the COVID-19 pandemic.
新兴的耐碳青霉烯肠杆菌科细菌（CRKP）菌血症由于治疗选择有限和死亡率增加而带来重大的公共卫生风险。欧洲大陆包括我国的 分离株的碳青霉烯类耐药率在 25%至 50%之间。
评估最近在我们中心发病率不断上升的耐碳青霉烯类肠杆菌科细菌菌血症的特征。我们旨在确定分离株对碳青霉烯类以外抗生素的耐药率，鉴定负责的碳青霉烯酶基因，评估抗生素的疗效，确定死亡率，探索菌株间的克隆性，并研究 COVID-19 大流行对所有这些因素的影响。
回顾性观察性研究。
这项研究纳入了年龄在 18 岁及以上且经历过美罗培南耐药 菌血症的患者。采用 Kirby-Bauer 纸片扩散法确认美罗培南耐药。采用梯度试验确定美罗培南最小抑菌浓度（MIC）水平，采用纸片洗脱技术确定多粘菌素 MIC 水平。通过聚合酶链反应（PCR）评估碳青霉烯酶基因，通过随机引物 PCR 技术进行克隆性分析。
研究共纳入 230 例患者，平均年龄为 63.1±15.9 岁，其中 58.7%为男性。74.8%的患者检出耐碳青霉烯类肠杆菌科细菌的 OXA-48，12.6%检出新德里金属β-内酰胺酶（NDM），7.8%检出 OXA-48+NDM，4.8%检出 KPC。14 天和 30 天死亡率分别为 57%和 69.6%。30 天死亡率的多变量分析显示了几个关键因素，包括在重症监护病房发生菌血症、COVID-19 大流行期间发生菌血症、混合菌血症、留置静脉导管、血小板计数≤140000/μl、降钙素原水平≥6μg/l 和 Charlson 合并症评分≥3。值得注意的是，COVID-19 大流行期间 和 基因显著上调，而 基因下调。此外，14 天和 30 天死亡率均显著增加。
在本研究中，最常见的碳青霉烯酶基因是 OXA-48；然而， 基因的数量最近有所增加。通过克隆性分析未发现优势流行株。大流行前的聚类率为 68%，大流行期间增加到 85.7%。COVID-19 大流行期间感染控制措施的重要性体现在聚类率和死亡率的上升。
