Antibiotic Susceptibility of Environmental Legionella pneumophila Strains Isolated in Northern Italy

Legionella pneumophila is ubiquitous in aquatic environments and responsible for severe pneumonia in humans through inhalation of aerosol containing Legionella spp. Macrolides and fluoroquinolones are frequently used antimicrobials, but treatment failures are increasingly being reported. As susceptibility testing is not routinely performed, this study aimed to determine the minimum inhibitory concentrations (MICs) on 58 environmental Legionella pneumophila strains (24 of serogroup 1 and 34 of non-serogroup 1) isolated in Northern Italy. MICs of azithromycin, erythromycin, ciprofloxacin, levofloxacin, and rifampicin were determined by the microdilution method using buffered yeast extract broth supplemented with α-ketoglutarate (BYEα). Seventy-five percent of Legionella pneumophila isolates showed MIC values below the tentative highest MICs indicated by the European Committee on Antimicrobial Susceptibility Testing (EUCAST); rifampicin was the most active agent with MIC90 values below 0.008 mg/L. Interestingly, one isolate was tested and found to be PCR-positive for the azithromycin LpeAB active efflux system, further confirmed by the reserpine/resazurin microtiter assay. In conclusion, this study has provided additional susceptibility data for environmental Legionella pneumophila isolates from Northern Italy demonstrating, in general, low MICs values for the tested antimicrobials, although one strain tested was shown to possess the LpeAB resistance determinant, indicating that future surveillance studies are warranted.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:18

Enthalten in:

International journal of environmental research and public health - 18(2021), 17 vom: 04. Sept.

Sprache:

Englisch

Beteiligte Personen:

Cocuzza, Clementina Elvezia [VerfasserIn]
Martinelli, Marianna [VerfasserIn]
Perdoni, Federica [VerfasserIn]
Giubbi, Chiara [VerfasserIn]
Vinetti, Maria Erica Alessandra [VerfasserIn]
Calaresu, Enrico [VerfasserIn]
Frugoni, Sergio [VerfasserIn]
Scaturro, Maria [VerfasserIn]
Ricci, Maria Luisa [VerfasserIn]
Musumeci, Rosario [VerfasserIn]

Links:

Volltext

Themen:

Anti-Bacterial Agents
Antimicrobial susceptibility testing
Doxycycline
Fluoroquinolones
Journal Article
Legionella pneumophila
LpeAB active efflux system
Macrolides
Minimum inhibitory concentrations
Reserpine coupled REMA assay
Rifampicin

Anmerkungen:

Date Completed 25.10.2021

Date Revised 25.10.2021

published: Electronic

Citation Status MEDLINE

doi:

10.3390/ijerph18179352

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM330441973