Antibacterial activity of selected medicinal plants used for the management of chicken diseases by poultry farmers in Najjembe Sub-County, Buikwe District, Uganda

Abstract

Background: The use of conventional antibiotics in the management of chicken diseases has accelerated the development of antibiotic resistance. Plants are a source of new novel antibiotics that are effective and cheap. The study documented locally used medicinal plants for the management of chicken diseases and investigated their antibacterial potential against chicken related bacteria responsible for chicken diseases.

Methods: Data on the use of medicinal plants was collected through a semi-structured questionnaire and during a field survey to collect the medicinal plants. Plant extracts were obtained through maceration of the plant materials using solvents of different polarities. Phytochemical analysis was carried out using the protocols of Guyasa et al (2018). The antibacterial activity of the plant extracts was determined using the disc diffusion method.

Results: The commonly used plant species were Aloe vera L., Ocimum gratissum L., Nicotiana tabacum L., Bidens pilosa L., and Vernonia amygdalina Del. Plant extracts were applied orally accounting for (98%). All the bacteria were sensitive to the plant extracts tested. Ethanolic extracts, at 0.5 mg/ml against E. coli had zones of inhibition ranging from 10-16 mm and 17-22 mm for S. aureus. Water extracts at 0.5 mg/ml against S. aureus had zones of inhibition ranging between 10-15 mm. The MIC of ethanolic extracts of the plant studied ranged from 0.03125-0.25 g/ml against E. coli and 0.03125-0.125 g/ml against S. aureus. The MIC of water extracts of the plant studied ranged from 0.125 to 0.25 g/ml against E. coli and 0.125 to 0.25 g/ml against S. aureus. Ethanolic extract of Vernonia amygdalina Del. and Nicotiana tabacum L. showed MBC against E. coli at 0.125 g/ml and 0.03125 g/ml against S. aureus for Vernonia amygdalina Del. Water extract showed MBC at 0.125 g/ml for Aloe vera L. against E. coli and 0.125 g/ml against S. aureus for Ocimum gratissimum L. Conclusion: Aloe vera, Ocimum gratissum, Nicotiana tabacum, Bidens pilosa, and Vernonia amygdalina were the most used plants for the management of bacterial infections in chicken.

Keywords: Medicinal plants, Antibacterial activity, Ethanolic extracts, Water extracts, Chicken, S. aureus, E. coli