Ristori Maria Vittoria, Scarpa Fabio, Sanna Daria, Casu Marco, Petrosillo Nicola, Longo Umile Giuseppe, Lucia De Florio, Spoto Silvia, Chiantia Rosa Maria, Caserta Alessandro, Vescio Raffaella Rosy, Davini Flavio, Bani Lucrezia, Riva Elisabetta, Ciccozzi Massimo, Angeletti Silvia
Operative Research Unit of Laboratory, Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo, 200, 00128 Rome, Italy.
Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43b, 07100 Sassari, Italy.
Microorganisms. 2024 Dec 10;12(12):2541. doi: 10.3390/microorganisms12122541.
Multidrug-resistant is a significant healthcare challenge that particularly affects vulnerable patients through opportunistic nosocomial infections. Surveillance is crucial for monitoring the prevalence of these infections. Eighty-four KPC strains (2019-2022) were collected from patients admitted in Fondazione Policlinico Universitario Campus Bio-Medico. Strains were identified by MALDI-TOF and tested for antimicrobial susceptibility, and gene amplification was performed to identify the different blaKPC variants. Phylogenetic reconstructions were carried out using Bayesian methods. Additionally, to create a Bayesian skyline plot (BSP), additional analyses were conducted, running a simulation of 100 million generations under a Bayesian skyline model along with the uncorrelated log-normal relaxed clock model. To identify potential subgroups within genetic clusters and evaluate genetic variability among sequences, principal coordinate analysis (PCoA) was performed. In total, 84 isolates were classified as multidrug-resistant (MDR), characterized by resistance to three or more antibiotic classes, including carbapenems, and testing positive for KPC gene presence, and were included in the study. The Bayesian evolutionary tree for showed strongly supported branches but no genetic structure related to sampling dates or hospital departments. Phylogenetic analysis revealing a 73-year evolutionary span of strains. PCoA analysis identified three genetic outliers from 2022 and one from 2021, indicating higher genetic distances. The Bayesian skyline plot revealed increased genetic variability peaking at the end of 2019, followed by stabilization from early 2020 onward, with no significant changes in genetic variability thereafter. Overall, the study found no genetic structure correlating with sampling date or hospital department, suggesting significant variability in pathogen introduction during the pandemic. The increase in multidrug-resistant was linked to the influx of severe COVID-19 cases, prolonged hospitalizations, and heightened broad-spectrum antibiotic use, which likely facilitated resistance development and transmission amidst altered infection control practices.
多重耐药是一个重大的医疗挑战，通过机会性医院感染对脆弱患者产生特别影响。监测对于监控这些感染的流行情况至关重要。从罗马生物医学大学校立综合医院收治的患者中收集了84株KPC菌株（2019 - 2022年）。通过基质辅助激光解吸电离飞行时间质谱（MALDI - TOF）鉴定菌株，并检测其抗菌药敏性，进行基因扩增以鉴定不同的blaKPC变体。使用贝叶斯方法进行系统发育重建。此外，为了创建贝叶斯天际线图（BSP），进行了额外的分析，在贝叶斯天际线模型以及不相关的对数正态松弛时钟模型下运行了1亿代的模拟。为了识别基因簇内的潜在亚组并评估序列间的遗传变异性，进行了主坐标分析（PCoA）。总共84株分离株被分类为多重耐药（MDR），其特征为对包括碳青霉烯类在内的三种或更多抗生素类别耐药，并且KPC基因检测呈阳性，被纳入研究。[此处原文似乎缺失关于贝叶斯进化树所展示内容的完整描述]的贝叶斯进化树显示分支支持度高，但没有与采样日期或医院科室相关的遗传结构。系统发育分析揭示了菌株73年的进化跨度。PCoA分析从2022年中鉴定出三个遗传异常值，从2021年中鉴定出一个，表明遗传距离更高。贝叶斯天际线图显示遗传变异性在2019年底达到峰值，随后从2020年初开始稳定，此后遗传变异性没有显著变化。总体而言，该研究未发现与采样日期或医院科室相关的遗传结构，这表明在大流行期间病原体引入存在显著变异性。多重耐药[此处原文似乎缺失关于何种病原体多重耐药的完整描述]的增加与重症COVID - 19病例的涌入、住院时间延长以及广谱抗生素使用增加有关，这可能在感染控制措施改变的情况下促进了耐药性的发展和传播。
