Characterization of class 1 integrons and antibiotic resistance genes in multidrug-resistant Salmonella enterica isolates from foodstuff and related sources

Abstract

In recent years, an increase in the occurrence of antimicrobial resistance among Salmonella enterica has been observed in several countries, which is worrisome because S. enterica is one of the most common causes of human gastroenteritis worldwide. The aim of this study was to characterize class 1 integrons and antibiotic resistance genotypes in Salmonella enterica isolates recovered from foodstuff and related sources.Nineteen multidrug-resistant (MDR) Salmonella enterica isolates were recovered. Higher resistance rates to tetracycline (90%), streptomycin (80%), sulfamethoxazole-trimethoprim (80%), ampicillin (60%) and nalidixic acid (70%) were related to the presence of the tetA, aadA, sul1/sul2, bla TEM-1 genes, and a codon mutation at position 83 of the gyrA gene, respectively. Class 1 integrons harboring aadA, bla TEM-1 , sul1 or dhfr1 genes were detected in nine (45%) Salmonella enterica strains belonging to serotypes Brandenburg, Panama, Agona, Mbandaka and Alachua. Finally, clonal dissemination of S. Panama, S. Derby and S.Mbandaka was confirmed by PFGE. Detection of clonally related MDR Salmonella enterica suggests that endemic serotypes can be supported by class 1 integron-borne gene cassettes and/or mutations in drug targets. Emergence and dissemination of multidrug-resistant Salmonella enterica can have a major public health impact in an environment where large-scale suppliers ship their products.

Occurrence and antimicrobial resistance of Salmonella serotypes isolates recovered from poultry of Western Paran, Brazil

“…About the resistance patterns shown by S. typhimurium, Bauer-Garland et al (2006) reported the transmission of S. typhimurium multidrug-resistant and sensitive, noting that multi-resistant Salmonella are more virulent under selection pressure, which allows them to diffuse more quickly from animal to animal and also not responding well to antimicrobial therapy.About S. mbandaka, in a study on the characterization of class 1 integrons and antibiotic resistance genes in multidrug resistant S. enterica from foodstuff was reported genes resistant to ampicillin, chloramphenicol, nalidixic acid, sulfamethoxazole/trimethoprim, streptomycin and tetracycline (Ribeiro et al, 2011). This corroborates the results of this study.…”

Phenotypic and genotypic resistance profile of Salmonella Typhimurium to antimicrobials commonly used in poultry

“…Data from several researchers suggest that the indiscriminate use of antimicrobials can lead to resistance of several bacteria that, which can reach consumers through products of animal origin (Ribeiro et al, 2011).…”

“…It was not possible to detect a resistance gene in one ST sample with resistant phenotype for gentamicin. Ribeiro et al (2011) and Peirano et al (2006) also reported that it was not always possible to correlate phenotype and genotype. The absence of the gene in isolates showing phenotypic resistance suggested that there are other mechanisms related to resistance, warranting further research.…”

Salmonella in Indian ready-to-cook poultry: antibiotic resistance and molecular characterization

“…These results were consistent with earlier studies. 11,[26][27][28] Integrons may carry antibiotic resistance gene cassettes, which confer resistance to antimicrobials. 13 In the present study, 82% of the integron positive isolates were MDR.…”