TY - JOUR
T1 - Antimicrobial Resistance Genes in Legionella from Artificial Water Systems
T2 - Findings from a Two-Year Study
AU - Pereira, Bernardo Beirão
AU - Marrafa, Mário
AU - Cruz, Carolina
AU - Rodrigues, Lúcia
AU - Nunes, Filipa
AU - Monteiro, Silvia
AU - Santos, Ricardo
AU - Carneiro, Rui Neves
AU - Neto, Célia
AU - Aguilar, Joana
AU - Ferreiro, Nuno Rafael
AU - Passanha, Margarida
AU - Candeias, Gonçalo
AU - Fernandes, Aida
AU - Paixão, Paulo
AU - Chasqueira, Maria Jesus
PY - 2024/12
Y1 - 2024/12
N2 - Background: Legionella 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 Legionella population. Methods: The ARGs lpeAB and tet56 were detected in 348 samples, isolates, and DNA extracts using conventional PCR. In a subset of lpeAB-positive isolates, azithromycin (AZT) MIC values were obtained using the EUCAST protocol and LpeAB activity was evaluated through an efflux pump inhibition assay. Results: The lpeAB gene was found in 19% (66/348) of samples, with higher detection rates in the L. pneumophila and L. pneumophila sg1 subgroups, at 30% and 41%, respectively. A positive association between lpeAB and L. pneumophila sg1 was found. The MIC values of the lpeAB-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 L. longbeacheae and L. bozemanae was found to possess the tet56 gene. Conclusions: The lpeAB gene is predominant in L. pneumophila sg1. A few isolates with the lpeAB gene exhibited MIC values below the EUCAST tentative highest MIC values for wild-type isolates. Expanding ARG monitoring in Legionella is essential to assess the public health risk of Legionnaires’ disease.
AB - Background: Legionella 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 Legionella population. Methods: The ARGs lpeAB and tet56 were detected in 348 samples, isolates, and DNA extracts using conventional PCR. In a subset of lpeAB-positive isolates, azithromycin (AZT) MIC values were obtained using the EUCAST protocol and LpeAB activity was evaluated through an efflux pump inhibition assay. Results: The lpeAB gene was found in 19% (66/348) of samples, with higher detection rates in the L. pneumophila and L. pneumophila sg1 subgroups, at 30% and 41%, respectively. A positive association between lpeAB and L. pneumophila sg1 was found. The MIC values of the lpeAB-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 L. longbeacheae and L. bozemanae was found to possess the tet56 gene. Conclusions: The lpeAB gene is predominant in L. pneumophila sg1. A few isolates with the lpeAB gene exhibited MIC values below the EUCAST tentative highest MIC values for wild-type isolates. Expanding ARG monitoring in Legionella is essential to assess the public health risk of Legionnaires’ disease.
KW - antimicrobial resistance
KW - ARG
KW - Legionella
KW - Legionella pneumophila
KW - LpeAB
KW - Tet56
UR - http://www.scopus.com/inward/record.url?scp=85213422308&partnerID=8YFLogxK
U2 - 10.3390/antibiotics13121121
DO - 10.3390/antibiotics13121121
M3 - Article
C2 - 39766511
AN - SCOPUS:85213422308
SN - 2079-6382
VL - 13
JO - Antibiotics
JF - Antibiotics
IS - 12
M1 - 1121
ER -