ANTIBACTERIAL SENSIVITY OF DIFFETRENT STAGES OF GUAVA LEAVES AGAINST Escherichia coli ISOLATED FROM COMMERCIAL BROILERS

Abstract

The study was conducted in the Microbiology Laboratory of the Department of Microbiology and Hygiene, Sylhet Agricultural University (SAU) during the period of July 2011 to June 2012. Fresh samples of different stages of guava leaves such as immature, mature and adult (Pisidium guavaja) were collected from in and around Sylhet Agricultural University (SAU Campus), Government Goat farm, Balochar, Shivgang and Tilagor, Sylhet. Randomly leaf samples were collected into plastic zip lock bags with appropriate labeling and stored in an ice cooler until being transported to the laboratory for extraction to find the antibacterial sensitivity of different stages guava leaf extract against Escherichia coli isolated from commercial broilers. Isolation and identification of bacteria were confirmed on the basis of their morphology, staining, cultural and biochemical properties. Antibiotic sensitivity test was studied by Disc diffusion method.

In the present research work the mature guava leaves extract showed better, adult guava leaves extracts medium and immature extracts poor antibacterial activity against Escherichia .coli. All the extracts showed varying degrees of antimicrobial activity on the microorganism tested resulting in zone of inhibition of 7.0– 9.0mm.