Evaluation of Antibiotic Resistant Bacteria from Organic Fertilized Farm Soils and Waterleaf (Talinum triangulare) in Aluu, Rivers State, Nigeria

Abstract

The use of antibiotics in agriculture is believed to contribute to the spread of antibiotic resistance, and consumption of vegetables represents a route of direct human exposure to resistant bacteria found in soil. This study was carried out to isolate and characterize antibiotic resistant bacteria from poultry dropping fertilized farm soils in Aluu community Rivers State. Thirty-six (36) soil and waterleaf (Talinum triangulare) samples were collected for a period of three months from the vegetable farms and subjected to standard microbiological procedures such as standard plate counts, identification, sensitivity testing using Kirby-Bauer disk diffusion method and molecular identification. The total heterotrophic bacterial (THB), Staphylococcal, and total coliform counts ranged from2.72±0.52x106 to 7.30±3.54x106Cfu/g; 0x105to 4.30±0.28x105Cfu/g; 0x105 to 21.40±2.26x105Cfu/g and 2.65±0.21x105 to 3.10±0.85x105Cfu/g for FarmsA, B and C respectively. There was a significant difference (p˂0.05) in the total heterotrophic, coliform bacterial count but no significant difference in Staphylococcal and Salmonella-Shigella count between the different vegetable farms sampled in month one. THB, Staphylococcal, Faecal coliform (FC), coliform, Salmonella-Shigella counts ranged from3.80±1.83x106 to 4.69±1.69x106cfu/g; 1.08±0.04x105 to 1.40±0.11x105Cfu/g; 2.00±0.42x104 to 8.30±2.12x104Cfu/g; 3.95±0.21x105 to 5.95±0.21x105Cfu/g and 1.20±0.28x104to 2.40±0.85x104Cfu/g for FarmsA and B respectively. There was no significant difference (p˂0.05) in the THB, Salmonella-Shigella, Total coliform (TC) counts, but there was a significant difference in the Staphylococcal and faecal coliform counts between the different vegetable farms sampled for month two. The bacterial isolates identified were as follows; Escherichia coli, Enterobacter spp, Shigella spp, Salmonella spp, Pseudomonas spp Proteus spp, Staphylococcus aureus, Bacillus subtilis, Bacillus licheniformis, Serratia marcesens and Serratia nematodiphila. Forty-six (46) bacterial isolates were isolated from the soils and vegetables. Escherichia coli had the highest occurrence (75%) and Bacillus spp (9.09%) had the least occurrence. The susceptibility pattern of Bacillus spp, Staphylococcus spp, Enterobacter spp, Salmonella spp, Escherichia coli, Shigella spp, Pseudomonas sppand Proteus sppwere all susceptible to Ofloxacin, and gentamicin (100%) and resistant to Ceftazidime, Cefixime and Augmentin (100%). Hundred-percent (100%) of the bacterial isolates had multidrug resistance index greater than 0.2 and QnrA resistant gene were found in the resistant bacterial isolates. In conclusion, the use of antibiotic indiscriminately for agricultural purposes should be discouraged because of multiple antibiotic resistance.