Biofilm Producing Pseudomonas Aeruginosa in Patients with Lower Respiratory Tract Infections


  • Sabahat Rehman, Sara Najeeb, Nazish Babar, Sidra Zaman, Saleha Maqsood, Nusrat Ali



Background and Aim: Pseudomonas aeruginosa is a vital pathogen causing major life-threatening infections among respiratory disease patients that leads to higher morbidity and mortality. Lower respiratory tract infections (LRTIs) are amongst these infections commonly found in hospitalized patients. Antibiotic tolerant biofilms formation and bacterium high intrinsic resistance to antibiotics make these infections difficult to treat. The present study aimed to assess the biofilm producing pseudomonas aeruginosa in lower respiratory tract infections patients.

Methodology: This cross-sectional study was carried out on 246 Lower respiratory tract infections patients admitted to ICUs of Sharif Medical and Dental College Lahore and Mohi-ud-Din Teaching Hospital, Mirpur Azad Kashmir for the duration from June 2021 to December 2021. The signs and symptoms of LRTIs were investigated in each patient. Prior to study conduction, ethical approval was obtained from the institutes research and ethical committee. Each individual provided written informed consent. Identification of isolated organisms and antimicrobial sensitivity was done.  Microtiter method was used for all the isolated, to imperil the isolates of P. aeruginosa for biofilm detection. SPSS version 25 was used for the data analysis.

Results: Of the total 246 specimens consisted of sputum 198 (80.5%), pleural fluid 19 (7.7%), suction tube 16 (6.5%), and tracheostomy tip specimens 13 (5.3%).  The incidence of positive culture was 78 (31.7%). Out of 78 positive cultures, sputum 56 (71.8%) was the major factor followed by pleural fluid 3 (3.8%), suction tube 12 (15.4%) and tracheostomy tip 7 (9.0%). Of the 78 positive specimens, the prevalence of single bacterium and poly-microbial infection was 58 (74.4%) and 20 (25.6%) respectively. The poly-microbial infection consisted of sputum 10 (50%), pleural fluid 1 (5.0%), suction tube 6 (30.0%), and tracheostomy tube 3 (15%). Out of 78 positive culture specimens, isolated gram-negative bacteria were 102, out of which K. pneumonia and P. aeruginosa were present in 46 (45.1%) and 24 (23.5%) respectively. Regarding the resistance pattern of gram-negative respiratory pathogens, Cefepime (86.9%) and ceftriaxone (91.9%) were given higher resistance by K. pneumoniae. Likewise, higher numbers of Acinetobacter spp provided resistance to cefepime (86.7%) and ceftriaxone (87%). Out of 24 P. aeruginosa isolates, biofilm producers were found in 16 isolates, in which the incidence of strong, moderate, and weak biofilm producers was 3 (18.7%), 5 (31.3%), and 8 (50%) respectively. Sputum in 11 (68.8%) was the prevalent biofilm producer isolates followed by suction tube 4 (25%) and tracheostomy tube 1 (6.3%). The incidence of inpatients and outpatients were 15 (93.8%) and 1 (6.2%) respectively. 

Conclusion: Our study concluded that gram-negative bacteria was the predominant and had increased resistance to antibiotics in Lower respiratory tract infections (LRTIs) patients. In LRTIs, the most common organism was K. pneumonia. Also, P. aeruginosa isolated in LRTIs patients were susceptible to producing biofilm. Biofilm producers had higher resistance than biofilm non-producers.

Keywords: Biofilm producing P. aeruginosa, K. pneumonia, Lower respiratory tract infections