DETECTION AND ANTIBIOTIC RESISTANCE OF Escherichia coli AND Salmonella IN WATER AND AGRICULTURAL SOIL

Abstract

In order to quantify Escherichia coli and to identify presence of Salmonella, 51 water and 23 soil samples in four regions of the Culiacán Valley at Sinaloa, México, were taken and analyzed. In addition, resistance profile of Salmonella to ampicilline, ciprofloxacin, trimethoprim-sulfamethoxazole, tetracycline, streptomycine and gentamicin were determined, and the last three antimicrobials in E. coli. Soil samples analyzed had absence of both E. coli and Salmonella, whereas water contained 20 strains of Salmonella. Serotyping showed that 13 Salmonella strains were Typhimurium, 2 were Infantis, 1 Anatum, 1 Agona, 1 Oranienburg, 1 Minnesota and 1 Give. Analyzed water samples were 98 % contaminated with E. coli, with minimums of 4 CFU/100 mL, maximums of 4.5 x 105 CFU/100 mL and an average of 1.6 x 104 CFU/100 mL; some strains were isolated to evaluate the antimicrobials resistance profile. All isolated strains of Salmonella were susceptible to ampicilline, ciprofloxacin and trimethoprimsulfamethoxazole and 12 were resistance to tetracycline. Of the 46 strains of E. coli analyzed, 9 were resistant to tetracycline, 38 were resistant to streptomycine and one strain was resistant to gentamicina; 23 strains were of intermediate resistance. All Salmonella strains had high levels of resistance to CuSO4•5H2O in dosages between 1200 and 1600 µg mL^-1 of the copper concentration. The present study demonstrated the existence of numerous Salmonella serotypes and high levels of E. coli in water from the Culiacán Valley.