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.

Cocuzza, C., Martinelli, M., Perdoni, F., Giubbi, C., Vinetti, M., Calaresu, E., et al. (2021). Antibiotic susceptibility of environmental legionella pneumophila strains isolated in northern Italy. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH, 18(17) [10.3390/ijerph18179352].

Antibiotic susceptibility of environmental legionella pneumophila strains isolated in northern Italy

Cocuzza C. E.
;
Martinelli M.
Secondo
;
Perdoni F.;Giubbi C.;Frugoni S.;Musumeci R.
Ultimo
2021

Abstract

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.
Articolo in rivista - Articolo scientifico
Antimicrobial susceptibility testing; Doxycycline; Fluoroquinolones; Legionella pneumophila; LpeAB active efflux system; Macrolides; Minimum inhibitory concentrations; Reserpine coupled REMA assay; Rifampicin;
English
4-set-2021
2021
18
17
9352
open
Cocuzza, C., Martinelli, M., Perdoni, F., Giubbi, C., Vinetti, M., Calaresu, E., et al. (2021). Antibiotic susceptibility of environmental legionella pneumophila strains isolated in northern Italy. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH, 18(17) [10.3390/ijerph18179352].
File in questo prodotto:
File Dimensione Formato  
ijerph-18-09352-1.pdf

accesso aperto

Tipologia di allegato: Publisher’s Version (Version of Record, VoR)
Dimensione 346.28 kB
Formato Adobe PDF
346.28 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/327014
Citazioni
  • Scopus 10
  • ???jsp.display-item.citation.isi??? 11
Social impact