St. Xavier's College
16 November 16
Thesis or project
Antibiotic sensitivity test, bacterial isolates, LRTI, MDR.
Introduction: Lower respiratory tract infection (LRTI) is one of the major causes of
morbidity and mortality in young children and elderly. It is among top ten diseases of
Nepal and accounts for deaths of 2.6 million people per year.
Objective: The objective of this was to identify causative agent of LRTI and to
determine the efficacy of antimicrobial agents in-use, with special interest to multidrug
resistance (MDR) following standard microbiological methods.
Method: The study was carried out in 240 sputum samples in the laboratory of
Microbiology Department of Chitwan Medical College Teaching Hospital for 6 months
(April- November, 2010).
Results: Total positive result was observed in 85 cases (35.42%). Infection rate in Males
(58%) was higher than in females (42%). LRTI was found most prevalent in age group of
61-75 years. Altogether 9 different types of bacteria were identified majority of which
were Gram-negative bacteria (73%) among which Pseudomonas spp. was the commonest
isolate 34% followed by Klebsiella pneumoniae (27%). The antibiotic susceptibility test
of the isolates showed that gentamicin (100%) was the most effective antibiotic against
Gram-positive bacteria and least effective was penicillin (100%). But different isolates of
Gram-negative bacteria showed variable response towards different antibiotics. In case of
Pseudomonas spp. carbenicillin (100%) was the most effective antibiotic and the least
effective was ampicillin (100%) while in case of Klebsiella pneumoniae amikacin
(100%) was the most effective. In case of Acinetobacter spp. chloramphenicol (70%) was
the most effective and least effective was ceftazidime (100%). In case of E.coli amikacin
(85.71%) was the most effective and least effective was ampicillin (100%). In case of
Enterobacter spp. none of the antibiotics used were effective. The prevalence of MDR
was 100% in Enterobacter spp., 90% in E. coli, 80% in S. aureus, 69% in Klebsiella
pneumoniae, 50% in Acinetobacter spp., 33% in Streptococcus pneumoniae and 30% in
Conclusion: The study shows increasing number of respiratory pathogens resistant to
antimicrobials in-use to treat the infection.