Bronchial bacterial colonization and the susceptibility of isolated bacteria in patients with lung malignancy.

Background: Postoperative pneumonia (POP) remains a leading cause of mortality following lung surgery. Recent studies have confirmed that the respiratory tract below the vocal cords is not sterile and often harbours potentially pathogenic microorganisms (PPMs), putting patients with lung malignancies at an increased risk for pulmonary infections.

Patients and methods: The study analysed 149 patients who underwent bronchoscopy for lung lesions suspected to be lung cancer. Protected specimen brush (PSB) samples were obtained during bronchoscopy prior to any specific treatment. Bacterial identification and antimicrobial susceptibility testing were conducted on the isolated strains.

Results: Bacterial colonization was detected in 88.6% of patients, with 21.5% carrying PPMs. Notably, patients with type 2 diabetes exhibited a higher rate of PPM colonization compared to others. Antibiotic susceptibility testing showed no significant differences in efficacy between amoxicillin with clavulanic acid and first-generation cephalosporin in both colonized patients and those with PPMs. Importantly, no multidrug-resistant bacteria were identified.

Conclusions: Our findings indicate a slightly lower PPM colonization rate compared to previous studies, possibly due to the unique geographic characteristics of the study population. The absence of significant differences in bacterial susceptibility between the two tested antibiotics highlights the need for further research to refine perioperative infection management strategies.