Resistance of Bacteria Isolates from Cabbage ( Brassica oleracea), Carrots ( Daucus carota) and Lettuce ( Lactuca sativa) in the Kumasi Metropolis of Ghana

Abstract

Despite the benefits humanity derives from vegetables, they are as well a good source of foodborne illnesses when contaminated with pathogenic microorganisms especially the antibiotic resistant ones. This study evaluated the antibiotic resistance of bacteria isolated from three commonly consumed vegetables; cabbage (Brassica oleracea), carrots (Daucus carota) and lettuce (Lactuca sativa) in the Kumasi Metropolis in Ghana. The bacteria isolates were subjected to antimicrobial susceptibility testing using the Kirby-Bauer disc diffusion method on Mueller-Hinton agar. A total of 78 bacteria isolates were obtained from the three vegetables with the Gram-positive bacteria accounting for 23.08% (18/78) whilst the Gram-negative bacteria accounted for 76.92% (60/78). The Gram-negative bacteria consisted of Acinectobacter spp., Aeromonas salmonicida, Aeromonas spp., Chryseomonas loteola, Citrobacter spp., Enterobacter cloacae, Enterobacter sakazakii, Erwinia nigrifluence, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeroginosa, Salmonella spp. and Serratia spp. while Gram-positive bacteria consisted of Brevibacillus spp., Brochothrix thermosphacter, Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus spp. All the Gram-positive bacteria isolates showed 100% resistance to penicillin, ampicillin and flucloxacillin, 88.2% were resistant to cefuroxime with 64.7% resistant to tetracycline and 17.6% resistant to cotrimoxazole but were all sensitive to gentamycin. For the Gram-negative bacteria, 96.7% were resistant to ampicillin with 90% being resistant to cefuroxime, 73.3% and 60% were resistant to chloramphenicol and tetracycline, respectively, but unlike the Gram-positives, 15% of the Gram-negative bacteria were resistant to gentamycin. All the Gram-positive isolates demonstrated multi antibiotic resistance (MAR), with Staphylococcus aureus and Streptococcus spp. being resistant to seven (7) out of the eight (8) tested antibiotics. For the Gram-negative bacteria, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeroginosa, Salmonella spp., Citrobacter spp. and Enterobacter were resistant to all eight (8) antibiotics. The implication of the findings in this study presents vegetables as a potential vehicle for microbial food poisoning as well as a source of infectious diseases that cannot be treated with commonly used antibiotics. Thus, good practices should be undertaken to reduce if not eliminate contamination of vegetables.