NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisboa, Portugal.
Comprehensive Health Research Center, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisboa, Portugal.
Front Cell Infect Microbiol. 2023 Apr 21;13:1141115. doi: 10.3389/fcimb.2023.1141115. eCollection 2023.
Legionnaires' Disease is a pneumonia caused by spp., currently treated empirically with fluoroquinolones and macrolides. In this study, we aim to describe the antibiotic susceptibility pattern of environmental recovered in the south of Portugal.
Minimal inhibitory concentration (MIC) determination of 57 isolates (10 Lp sg 1, 32, Lp sg 2-14 15 L. spp) was achieved by broth microdilution, as described by EUCAST, for azithromycin, clarithromycin, ciprofloxacin, levofloxacin, and doxycycline.
Fluoroquinolones were the most active antibiotic, displaying the lowest MIC values in contrast to doxycycline which had the highest. MIC90 and epidemiological cut-off (ECOFF) values were, respectively, 0.5/1 mg/L for azithromycin, 0.125/0.25 mg/L for clarithromycin, 0.064/0.125 mg/L for ciprofloxacin, 0.125/0.125 mg/L for levofloxacin and 16/32 mg/L for doxycycline.
MIC distributions were higher than reported by EUCAST for all antibiotics. Interestingly, two phenotypically resistant isolates with high-level quinolone resistance were identified. This is the first time that MIC distributions, and tet56 genes have been investigated in Portuguese environmental isolates of .
军团病是一种由 spp.引起的肺炎，目前临床上经验性地使用氟喹诺酮类和大环内酯类药物进行治疗。在这项研究中，我们旨在描述在葡萄牙南部回收的环境 中抗生素敏感性模式。
通过肉汤微量稀释法，按照 EUCAST 的描述，确定了 57 株 （10 株 Lp sg 1、32 株、Lp sg 2-14 株中的 15 株）分离株的最小抑菌浓度（MIC），用于阿奇霉素、克拉霉素、环丙沙星、左氧氟沙星和强力霉素。
氟喹诺酮类是最有效的抗生素，其 MIC 值最低，而强力霉素的 MIC 值最高。MIC90 和流行病学截断值（ECOFF）值分别为阿奇霉素 0.5/1 mg/L、克拉霉素 0.125/0.25 mg/L、环丙沙星 0.064/0.125 mg/L、左氧氟沙星 0.125/0.125 mg/L 和强力霉素 16/32 mg/L。
所有抗生素的 MIC 分布均高于 EUCAST 报道的值。有趣的是，鉴定出了两株具有高水平喹诺酮耐药性的表型耐药分离株。这是首次在葡萄牙环境分离株中调查了 MIC 分布、 和 tet56 基因。
