Increased antibiotic resistance of Pseudomonas aeruginosa isolates from chronic rhinosinusitis patients grown in anaerobic conditions

Jannatul Ferdoush Tuli; Mahnaz Ramezanpour; Clare Cooksley; George Spyro Bouras; Kazuhiro Ogi; Sholeh Feizi; Roshan Nepal; Alkis James Psaltis; Peter-John Wormald; Sarah Vreugde

doi:10.1002/lio2.1244

Increased antibiotic resistance of Pseudomonas aeruginosa isolates from chronic rhinosinusitis patients grown in anaerobic conditions

Laryngoscope Investig Otolaryngol. 2024 May 9;9(3):e1244. doi: 10.1002/lio2.1244. eCollection 2024 Jun.

Authors

Jannatul Ferdoush Tuli^{1

2}, Mahnaz Ramezanpour^{1

2}, Clare Cooksley^{1

2}, George Spyro Bouras^{1

2}, Kazuhiro Ogi³, Sholeh Feizi^{1

2}, Roshan Nepal⁴, Alkis James Psaltis^{1

2}, Peter-John Wormald^{1

2}, Sarah Vreugde^{1

2}

Affiliations

¹ Department of Surgery-Otolaryngology, Head and Neck Surgery University of Adelaide Adelaide South Australia Australia.
² Basil Hetzel Institute for Translational Health Research, Central Adelaide Local Health Network, The Queen Elizabeth Hospital Woodville South South Australia Australia.
³ Division of Otorhinolaryngology Head and Neck Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences University of Fukui Fukui Japan.
⁴ CSIRO Marine and Atmospheric Research The Commonwealth Scientific and Industrial Research Organisation (CSORO) Hobart Tasmania Australia.

Abstract

Introduction: In chronic rhinosinusitis (CRS), the congestion and blockage of the nose can cause anaerobic conditions within the sinus cavities which may promote the expression of virulence and antibiotic resistance genes in invading pathogens. Pseudomonas aeruginosa is a facultative anaerobic bacteria and causes severe recalcitrant CRS. In this study, we aimed to evaluate the antimicrobial resistance of P. aeruginosa isolates of CRS patients in planktonic and biofilm form grown in aerobic and anaerobic conditions.

Methods: P. aeruginosa clinical isolates of CRS patients (n = 25) were grown in planktonic and biofilm form in aerobic and anaerobic conditions. Minimum inhibitory concentrations (MIC) of planktonic forms and minimum biofilm eradication concentrations (MBEC) were determined. Additionally, metabolic activity by fluorescein diacetate assay, biofilm biomass by crystal violet assay and eDNA concentration were assessed in both conditions.

Results: P. aeruginosa planktonic cells grown in anaerobic condition exhibited increased gentamicin resistance (p < .01), whereas P. aeruginosa biofilms grown in anaerobic condition displayed significantly increased MBEC values for gentamicin (p < .0001) and levofloxacin (p < .001). The metabolic activity of anaerobic biofilms was significantly higher compared with aerobic biofilms (p < .0001). However, the biofilm biomass of isolates grown in aerobic conditions was higher than anaerobic conditions (p < .5).

Conclusion: P. aeruginosa isolates from CRS patients grown in anaerobic conditions showed significantly increased resistance to antibiotics with an increased metabolic activity but decreased biofilm biomass.

Level of evidence: NA.

Keywords: anaerobic conditions; antibiotic; chronic rhinosinusitis; pseudomonas aeruginosa; resistance.