Abstract

There is a high prevalence of multidrug resistant pathogenic bacteria from food and companion animals in Nigeria due to abuse and misuse of antibiotics. The current work was carried out to study the antimicrobial activity of the leave extract ofParquetina nigrescens on ten multidrug resistant pathogens including: Escherichia coli, Salmonella enterica Gallinarum, Corynebacterium diphtheriae, Acinetobacter species, Staphylococcus aureus and Pseudomonas diminuta that were resistant to 7 to 10 conventional antibiotics. The ten strains of the organisms tested were either isolated from cases of otitis media in dogs following more than a year of antibiotic misuse and or abuse or from internal organs of poultry that died of septicaemic disease conditions. The tested leaves extract produced activity in only one of the C. diphtheriae isolated from ear swab of one of the otitis media cases with 16±0.0 mm zone of inhibition at 100 mg/mL when compared with 30±0.0 mm at 10 µg/mL of gentamycin (positive control). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the tested extract for the isolate were 25 and 400 mg/mL respectively as compared to the respective MIC and MBC of 40 and 320 µg/mL for gentamycin.

Key words: Parquetina nigrescens, multidrug-resistant, otitis, poultry, dog, Nigeria.