Evaluation of antibacterial activities of crude extracts of Ocimum gratissimum (Scent leaf) and Vernonia amygdalina (Bitter leaf) on some multidrug resistant pathogens isolated from free-range and broiler chikens

Abstract

Antibiotic use in poultry is one of the major ways of spreading antibiotic resistance. This study determined the prevalence of some multidrug resistant bacteria isolated from chickens and the antibacterial activities of Ocimum gratissimum and Vernonia amygdalinaon selected multidrug resistant isolates. One hundred and fifty (150) chicken fecal samples (50 free-range and 100 broiler) were aseptically collected. Staphylococcus aureus, Enterococcus and Salmonella species were isolated from the samples using standard procedures. The isolates were subjected to antibiotic sensitivity tests. Randomly selected total drug resistant isolates were subjected to antibacterial susceptibility tests. Prevalent rates of 68%, 37% and 42% for S. aureus, Enterococcus and Salmonella species respectively among free range chickens, and of 87%, 56% and 68% for S. aureus, Enterococcus and Salmonella species respectively among broiler chickens were observed. Fifty percent (50%) and above of S. aureus were sensitive to ceftriaxone, ciprofloxacin and clindamycin, while 30% were totally resistant to all the antibiotics. Similarly, more than 70% of S. aureus from broilers were resistant to Erythromycin, Ampicillin, Cloxacillin, Levofloxacin, Cephalexin, Ciprofloxacin, Gentamycin, Ofloxacin and Clindamycin. At least 80-100% of the isolates showed total resistance to all the antibiotics used, except Ceftriaxone and Ciprofloxacin. Fifty percent (50%) of Enterococcus from free-range chickens were susceptible to 60% of the drugs, while 100% of the isolates from broilers were totally resistant to 50% of the tested antibiotics. Resistance profiles in Salmonella specie were 50-70% and 77-100% for free range and broilers respectively. The antibacterial activities of the plant extracts show that 80% and 60% of S. aureus were sensitive to V. amygdalina and Ocimum gratissimum extracts respectively. The same level of sensitivity was observed in Enterococcus and Salmonella species. However, the two species both showed 80% and 60% sensitivity levels to both extracts.