Pereira Bernardo Beirão, Marrafa Mário, Cruz Carolina, Rodrigues Lúcia, Nunes Filipa, Monteiro Silvia, Santos Ricardo, Carneiro Rui Neves, Neto Célia, Aguilar Joana, Ferreiro Nuno Rafael, Passanha Margarida, Candeias Gonçalo, Fernandes Aida, Paixão Paulo, Chasqueira Maria Jesus
Laboratory of Microbiology, Nova Medical School, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal.
Laboratório de Análises de Água, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal.
Antibiotics (Basel). 2024 Nov 23;13(12):1121. doi: 10.3390/antibiotics13121121.
species are the causative agent of Legionnaires' disease and, as ubiquitous waterborne bacteria, are prone to antimicrobial resistance gene (ARG) acquisition and dissemination due to the antimicrobial contamination of natural environments. Given the potential health risks associated with ARGs, it is crucial to assess their presence in the population.
The ARGs and were detected in 348 samples, isolates, and DNA extracts using conventional PCR. In a subset of -positive isolates, azithromycin (AZT) MIC values were obtained using the EUCAST protocol and LpeAB activity was evaluated through an efflux pump inhibition assay.
The gene was found in 19% (66/348) of samples, with higher detection rates in the and sg1 subgroups, at 30% and 41%, respectively. A positive association between and sg1 was found. The MIC values of the -positive isolates ranged from 0.064 to 2 mg/L. LpeAB inhibition resulted in 2- and 4-fold MIC reductions in 10 of the 13 isolates analyzed. One sample each of and was found to possess the gene.
The gene is predominant in sg1. A few isolates with the gene exhibited MIC values below the EUCAST tentative highest MIC values for wild-type isolates. Expanding ARG monitoring in is essential to assess the public health risk of Legionnaires' disease.
嗜肺军团菌是军团病的病原体，作为普遍存在的水生细菌，由于自然环境中的抗菌污染，易于获取和传播抗菌耐药基因（ARG）。鉴于与ARG相关的潜在健康风险，评估其在人群中的存在至关重要。
使用常规PCR在348个样本、分离株和DNA提取物中检测ARG。在一部分嗜肺军团菌阳性分离株中，使用欧洲抗菌药物敏感性试验委员会（EUCAST）方案获得阿奇霉素（AZT）的最低抑菌浓度（MIC）值，并通过外排泵抑制试验评估LpeAB活性。
在19%（66/348）的样本中发现了该基因，在嗜肺军团菌血清群1和血清群6的sg1亚组中检测率更高，分别为30%和41%。发现嗜肺军团菌血清群1和sg1之间存在正相关。嗜肺军团菌阳性分离株的MIC值范围为0.064至2mg/L。在分析的13株分离株中的10株中，LpeAB抑制导致MIC降低2倍和4倍。各发现1份嗜肺军团菌血清群1和血清群6的样本携带该基因。
该基因在嗜肺军团菌血清群1的sg1中占主导地位。少数携带该基因的分离株的MIC值低于EUCAST对野生型分离株暂定的最高MIC值。扩大对嗜肺军团菌的ARG监测对于评估军团病的公共卫生风险至关重要。
