K V Ramana^1,, Anand Kalaskar¹, Mohan Rao¹, Sanjeev D Rao¹

Lower respiratory tract infections (LRTI’s) are amongst the most common causes of morbidity and mortality arising from infectious diseases both in the developed and developing nations. Prompt clinical and laboratory diagnosis along with appropriate treatment strategies would be helpful in the management of both community and nosocomially acquired LRTI’s. Our study was aimed at evaluating the aetiology and antimicrobial susceptibility patterns of LRTI’s in a tertiary care teaching hospital in south India. The results of the current study revealed that among the samples tested 56 (52.83%) were positive for various bacteria, 6 (5.6%) were showing the growth of fungi and 44 (41.5%) were revealing no pathogens. Klebsiella pneumoniae (45.1%) was the predominant gram negative bacterial pathogen isolated followed by Citrobacter freundii (12.9%), Pseudomonas aeruginosa (9.6%), and Staphylococcus aureus (9.6%) was the significant gram positive bacterial pathogen followed by Streptococcus pneumoniae (5.6%). The antimicrobial susceptibility pattern of the isolated bacteria indicated the presence of multidrug resistance, the production of Extended spectrum beta lactamases (ESBL) (75%) and metallo-betalactamases/carbapenemases (MBL) (25%) among gram negative bacterial isolates and MRSA (16.6%) and VRSA (16%) among the gram positive bacterial isolates. With varied geographical prevalence, and different antimicrobial susceptibility patterns, it becomes imperative to regularly evaluate the aetiology and antibiotic profiles of LRTI’s and formulate regional guidelines that guide clinical, laboratory diagnosis and management of patients suffering from LRTI’s.

Keywords: lower respiratory tract infections (LRTI’s), aetiology of LRTI’s, antimicrobial susceptibility patterns, patient management