نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی دکتری گروه خاکشناسی دانشکده کشاورزی دانشگاه بوعلی سینا همدان
2 استاد گروه علوم خاک دانشکده کشاورزی دانشگاه بوعلی سینا همدان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Heavy metals may increase antibiotic resistance in bacteria. The aim of this study was to determine antibiotic-resistance of frequent Gram-negative isolates in agricultural, pasture and mine soils. Hence, 97 isolates from soil samples were selected and antibiotic (7 antibiotics) and heavy metal resistance were determined by disc diffusion and MIC methods. Based on the results, 50% of the Azotobactersfrom agricultural soilsand28.57% of those from pastures showed multi-resistant against amoxicillin, ampicillin, vancomycine and tetracycline. 62.5% of Enterobacterstrains from agricultural soils, 33.33% of pastures isolates and 35% of the mining soils isolates showed resistance to these antibiotics.87.5% of the agricultural soil Pseudomonas strains and 100% of pastures isolates showed also resistance to these antibiotics. According to the results, the resistance to streptomycin and doxycycline in three isolates was high, whereas it was the least for gentamicin. All isolates displayed resistance to lead and sensitivity to cadmium. All agricultural soil Azotobacterstrains, 57% of pasture isolates and 66.7% of mining waste isolates were multi-resistant to Pb, Hg and Ni. Abundance of Enterobacters, resistant to these metals from agricultural, pasture and mining waste samples was 45.83, 80 and 65%. 37.50 and 66.7% of Pseudomonas strains from agricultural and mining wastes showed also resistance to those metals. The high percentage of antibiotic-resistance may be attributed to the heavy metals in soils. Resistance to antibiotics in all soils was high. But, due to the favorable conditions ofagricultural soils, it seems that dangerous antibiotic-resistant bacteria may be spreading much more faster.
کلیدواژهها [English]