Published: 2021-02-25

Aerobic bacteriological analysis of bronchoalveolar lavage fluid in patients with pulmonary infection: a tertiary care hospital study

Shahida Akhtar, Asifa Nazir, Humaira Bashir


Background: Respiratory tract infection are an important cause of mortality and morbidity worldwide. The prevalent bacterial agents and their antimicrobial resistance patterns differs, both geographically and over time. Bronchoalveolar lavage has improved sensitivity and specificity of diagnostic techniques in diagnosis of pulmonary infections. The present study aimed to determine the current aerobic bacterial isolates and their sensitivity pattern obtained from the bronchoalveolar lavage (BAL) fluid of patients with pulmonary infection.

Methods: BAL samples received from the patients of suspected respiratory tract infections over a period of one year, from June 2018 to May 2019 were processed by standard methods for isolation and identification. The antimicrobial susceptibility was done by the Kirby-Bauer disc diffusion method as per the CLSI guidelines.

Results: Out of 322 BAL samples, 84 (26.08%) were found to be culture positive for bacterial isolates. Of those, 44 samples (52.38%) from among males and 40 samples (47.61%) from among females were culture positive .The predominant organism isolated was Pseudomonas aeruginosa 46 (54.76%) followed by Acinetobacter baumanii 13 (15.47%), Escherichia coli 10 (11.90%), Klebsiella pnuemoniae 6 (7.14%) Enterobacter sp 3 (3.57%), Staphylococcus aureus 3 (3.57%), Enterococcus sp 2 (2.38%) and Sphingomonas sp 1 (1.19%). The Gram-negative organisms showed maximum sensitivity to colistin (100%) while as vancomycin and linezolid were the most effective drugs against Gram positive organisms.

Conclusions: Bronchoalveolar lavage has improved sensitivity and specificity in diagnosis of pulmonary infections. It is important to have an updated local antibiogram for each hospital and regular surveillance and monitoring of antibiotic resistance and the changing patterns of the bacterial pathogens is a must for better patient management.


Bronchoalveolar lavage, Respiratory infection, Antimicrobial sensitivity, bacterial isolates

Full Text:



WHO. Global surveillance, prevention and control of chronic respiratory diseases. A comprehensive approach. 2007:5-14.

Koul PA. Chronic obstructive pulmonary disease: Indian guidelines and the road ahead. Lung India. 2013;30:175-7.

Srivastav P, Kumar P, Nirwan PS, Sharma M. Bacteriological profile and antibiogram pattern of lower respiratory tract infections in a tertiary care hospital in Northen India. IJPRBS. 2013;2(3):225-33.

Sánchez MM, Michavila AI, Núñez N, Alvarez LJ. Prognosis in patients with pneumonia and chronic obstructive pulmonary disease. Arch Bronconeumol. 2005;41(11):607-11.

Ahmed MS, Jakribettu RP, Meletath SK, Arya B, Vpa S. Lower respiratory tract infections (LRTIS) :An insight into the prevalence and the antibiogram of the Gram negative, respiratory bacterial agents. J Clin Diag Res. 2013;7(2):253-56.

Carlos J, Gomes P, Wilson L, Pedreira J, Evangelina MP, Araujo A, et al. Impact of BAL in the management of pneumonia with treatment failure-positivity of BAL culture under antibiotic therapy. Chest. 2000;118:1739-46.

Bhatia RS. Bronchoalveolar lavage: indications and present status. Lung India. 1994;12:27-9.

York MK, Gilligan P, L Church. Processing and Interpretation of Lower respiratory tract specimens. In Garcia LS, Isenberg HD. Clinical Microbiology Procedure Handbook. 2nd edition. ASM Press, Washington DC. 2007:3-11.

Collee, JG, Fraser AG, Marmion BP, Simmons A. McCartney M. Practical medical microbiology. 14th edition. New Delhi, India: Elsevier; 2006.

CLSI. Performance Standards for Antimicrobial Susceptibility Testing; 25th Informational Supplement. CLSI Document M100-S25. Wayne PA: Clinical and Laboratory Standards Institute. 2015.

Vélez L1, Correa LT, Maya MA, Mejia P, Ortega J, Bedoya V, et al. Diagnostic accuracy of bronchoalveolar lavage samples in immunosuppressed patients with suspected pneumonia: analysis of a protocol. Respir Med. 2007;101(10):2160-7.

Kottmann RM, Kelly J, Lyda E, Gurell M, Stalica J, Ormsby W, et al. Bronchoscopy with bronchoalveolar lavage: determinants of yield and impact on management in immunosuppressed patients. Thorax. 2011;66(9):823.

Müllerová H, Shukla A, Hawkins A, Quint J. Risk factors for acute exacerbations of COPD in a primary care population: a retrospective observational cohort study. BMJ Open. 2014;4(12):e006171.

Mishra SK, Kattel HP, Acharya J, Shah NP, Shah AS, Pokhrel BM, et al. Recent trend of bacterial aetiology of lower respiratory tract infections in a tertiary care center of Nepal. Int J Infect Microbiol. 2012;1(1):3-8.

Egbe CA, Ndiokwre1 C, Omoregie R. Microbiology of lower respiratory tract infections in Benin City, Nigeria. Malaysian J Med Sci. 2011;18(2):27-31.

Amutha C, Suganthi M, Radhika K, Leela KV, Jayachitra J. Bacterial profile of lower respiratory tract infections in adults and their antibiotic susceptibility pattern with detection of MRSA, ESBLs and MBLs. Int J Curr Microbiol App Sci. 2017;6(3):631-9.

Sharma AK, Prakash A, Kumar M. Bacterial profile, antibiotic sensitivity and resistance of lower respiratory tract infections in RIMS, Ranchi: A Tertiary Care Hospital. Int J Med Res Prof. 2016;2(1):149-54.

Thomas AM, Jayaprakash C, Amma GMR. The pattern of bacterial pathogens and their antibiotic susceptibility profile from lower respiratory tract specimens in a rural tertiary care centre. J Evolution Med Dent Sci. 2016;5(40):2470-6.

Khan S, Singh P, Sachan A. Bacterial etiological agents causing LRTIs and their resistance patterns. Ir Biomed J. 2015;19(4):240-6.

Ratna S. Bacteriological profile and antibiotic susceptibility pattern of lower respiratory tract infection in a tertiary hospital in north-east India. Int J Recent Sci Res. 2017;8(9):20337-40.

Verma D, Kumar P, Saxena N. Bacteriological profile and antibiogram pattern in lower respiratory tract infection in Kota Region (Raj). Research and Reviews. J Microbiol Virol. 2016;6(2):13-7.

Madhavi S, Ramarao MV, Janardhanrao R. Bacterial etiology of acute exacerbations of chronic obstructive pulmonary disease. J Microbiol Biotech Res. 2012;2(3):440-44.

Bajpai T, Shrivastav G, Bhatambare GS, Deshmukh AB, Chitnis V. Microbiological profile of lower respiratory tract infections in neurological intensive care unit of tertiary care center from central India. J Basic Clin Pharm. 2013;4(3):51-5.

Kumari VHB, Agarathna SN, Chandramuki A. Antimicrobial resistance pattern among Aerobic gram-negative bacilli of lower respiratory tract specimens of intensive care unit in a Neuro centre. Indian J Chest Allied Dis. 2007;49:19-22.

Sofianou DC, Constandinidis TC, Yannacou M, Anastasiou H, Sofianos E. Analysis of risk factors for Ventilator associated pneumonia in a multidisciplinary intensive care unit. Eur J Clin Microbiol Infect Dis. 2000;19:460-3.