Isolation of antimicrobial-resistant Salmonella from two estuarine regions of Ceará State, Brazil

Abstract

Main goal of this study was to isolate and determine the antimicrobial susceptibility of bacteria of the genus  Salmonella in 84  water samples from the estuarine environment of Acaraú and Jaguaribe rivers, in Ceará State, both with shrimp farming activities.The  strains were tested for susceptibility to ten antibiotics, namely nalidixic acid, ampicillin, ciprofloxacin, ceftriazona, chloramphenicol,  gentamicin, imipenem, nitrofurantoin, trimethoprim and tetracycline. The Minimum Inhibitory Concentration in antibiotics was  performed following the technique of broth macrodilution. Measurements of pH, temperature and salinity were taken in the field. Out  of 103 confirmed Salmonella strains, 90 and 13 were found int Acaraú and Jaguaribe rivers, respectively, belonging to the serovars: S.  ser.Newport, S.ser. Saintpaul , S. ser. Panama , S. ser . Rubislaw , S.ser . Albany,S. ser. Anatum S. ser. Corvallis , S. ser.Madelia .  Based on these results Acaraú River proved to be more contaminated than Jaguaribe River, with 25% and 75% of strains with plasmi - dial and chromosomic resistances. These results highlight two problems of public health: the presence of  Salmonella strain resistant to  antimicrobials and the possibility of human contamination through consumption of shellfish. Moreover, economic losses must be ac- counted for as derived from market limitations of farmed shrimp overseas due to requirements concerning the exemption of such patho- gens in the productive systems.