Bacteriological Analysis of Bronchoalveolar Lavage Fluid in Patients with Respiratory Tract Infections

Abstract

Background and Aim: Bacterial respiratory infections are most commonly causes of illness for all age group patients
in ICU. Most of the patients suffer from urosepsis, postoperative disease and lower respiratory infection when
admitted in ICU’s. Broncho alveolar lavage (BAL) is an ideal sample that allows the recovery of pathogens cellular
and noncellular components from the epithelial surface of lower respiratory tract. This study was performed to
detect pathogenic organisms by microscopy of BAL fluid and isolate and identify various bacteria and fungi from
BAL fluid in culture and analyze their antibiogram.
Material and Methods: The cross-sectional prospective study was conducted in the Department of Microbiology,
tertiary care teaching hospital, India. The study included 200 BAL samples taken from all consecutive patients
referred with suspicion of pneumonia. Bronchial wash was done with the help of fibreoptic bronchoscope under
local anaesthesia. All BAL samples were cultured on three bacteriological media agar plates using a sterile 4mm
nichrome loop (0.01ml), and incubated at 37 C for 72 hours for quantitative bacterial culture using standard
laboratory techniques. Bacterial isolates were identified by performing standard microbiological procedures such
as study of colony morphology, Gram staining and standard biochemical tests.
Results: Out of the total 200 samples, 120 (60%) were from males, and 80 (40%) were female patients. The
predominant GNB was Klebsiella pneumoniae 45 (61%), followed by Pseudomonas aeruginosa 22(30%), Esch.
coli 6(8%) and the fungal isolate was Aspergillus niger 5(1%). Klebsiella & Pseudomonas were highly sensitive to
amikacin, piperacillin-tazobactam, imipenem, gentamycin, followed by tobramycin.
Conclusion: Results of the present study demonstrate the high incidence of gram-negative isolates. The study also
suggests that regular antimicrobial sensitivity monitoring should be done as most isolates are highly resistant to
cephalosporin and other commonly used antimicrobials