A preliminary investigation on methods of reducing antibiotic resistant bacteria in broiler litter in selected farms in mid country, Sri Lanka

Antibiotic residues and bacteria resistant to antimicrobial have been found in poultry litter, which is popular low cost manure in agriculture. A study was conducted to investigate a pre-treatment method to reduce antibiotic resistant bacteria in poultry litter. Poultry litter was collected from eleven medium-scale broiler farms in Kandy. Total and antibiotic resistant (tetracycline and/or enrofloxacin) culturable bacteria were isolated using Tryptic Soy Agar supplemented with 0 or 100 ppm of each antibiotic. A fresh and a cured broiler litter sample were collected from one farm and treated with different temperatures (25°C, 40°C, 60°C and 80°C for 24 hours), neem seed extract (10 and 1000 ppm for 4 day) and neem dry leaves (10% w/w for 4 days) in triplicates. Total and antibiotic resistant bacteria in treated litter were assessed. Broiler litter from all farms contained tetracycline resistant bacteria. Heating at 80°C reduced tetracycline resistant bacteria by 96-100% compared to 25°C. Neem seed extract at 10 ppm reduced tetracycline resistant bacteria by 75-96%. Treating broiler litter with high temperature (>60°C) and neem seed extract (10ppm) could minimize spread of antibiotic resistant bacteria to the environment.

Tropical Agricultural Research Vol. 26 (2): 409 – 414 (2015)