Lower respiratory tract bacterial colonization among newly diagnosed lung cancer patients

Abstract Background Recent studies suggest a mutual relationship between lung cancer and microbial colonization of the bronchial airways. However, data on this subject is scarce, especially among Egyptian studies. This study aimed to evaluate the rate and type of bronchial colonization in patients with proven lung cancer at the time of diagnosis by bronchoscopy. Fifty patients who fulfilled the study inclusion criteria underwent bronchial wash or bronchoalveolar lavage samples and were subjected to bacteriological culture and susceptibility. Results Bacterial colonization was recorded in 40% of the studied patients, all of which were potentially pathogenic microorganisms (PPMs). All 23 isolated organisms were Gram-negative bacteria of which 39% were multidrug-resistant (MDR). The most common were Pseudomonas aeruginosa 73.9% and Klebsiella spp. 17.4%. Double growth was detected in 15% of cases. Bronchial colonization in lung cancer had a statistically significant relationship with male gender ( p = 0.032), old age ( p = 0.037), and chronic obstructive pulmonary disease ( p = 0.001). The highest antibiotic sensitivity was observed with Imipenem (69.2%), while the highest antibiotic resistance rates were observed with Ampicillin/Sulbactam and Ceftriaxone (100%). Conclusion Gram-negative PPMs were isolated in 40% of lung cancer cases at the time of diagnosis by bronchoscopy with higher frequency among males, old age, and patients with associated COPD. Among isolated organisms, 39% were MDR pathogens.