Antimicrobial activity of propolis extract on bacteria isolated from nasopharynx of patients with upper respiratory tract infection admitted to Central Hospital, Benin City, Nigeria

Abstract

The study was aimed at determining the bacterial agents of the upper respiratory tract infection (URTI) and the susceptibility of isolates to propolis. Propolis extract was obtained by 70% ethanol and serial dilutions of 0.25, 0.5, 1, 2, 4, 8 and 10 µg/ml prepared. A total of 250 throat swabs were obtained from patients (age between 15 - 30 years) which were diagnosed with upper respiratory tract infection attending the central hospital, Benin City. Samples were collected between February and December, 2008 from 142 (56.8%) males and 108 (43.2%) females, inoculated on blood agar, eosin methylene blue agar and chocolate agar and incubated at 37°C for 24 - 48 h aerobically except for chocolate agar which was incubated microaerophically. The isolates were characterized by standard microbiological procedures. Of the 250 samples, 160 (64%) had positive cultures with Haemophilus influenzae having the highest prevalence (20.8%), followed by Klebsiella pneumoniae (19.2%), Streptococcus pneumoniae (12.0%), Moraxella catarrhalis(10%), Streptococcus pyogenes (2%). The highest rate of isolates was from the age group of 15 - 18 years (91). This was significantly higher than other groups p > 0.05.M. catarrhalis and S. pyogenes were not isolated in age group 23 – 26. propolis antimicrobial activity revealed that all isolates were sensitive to propolis at all concentrations with K. pneumoniae and S. pneumonia having zones of inhibition of 32 and 30 mm respectively. The findings suggest that propolis is a very effective antimicrobial agent for the treatment and management of URTI caused by bacterial species. Key words: Upper respiratory tract infection, minimum inhibitory concentration, propolis, bacteria, antimicrobial activity.