Molecular mechanisms of resistance in multidrug-resistant serovars of Salmonella enterica isolated from foods in Germany

Abstract

This study confirms the role of foods of animal and other origin as a reservoir of multidrug-resistant Salmonella and underlines the need for continuing surveillance of food-borne zoonotic bacterial pathogens along the food chain.

Diagnostic Accuracy of Class 1 Integron PCR Method in Detection of Antibiotic Resistance in Salmonella Isolates from Swine Production Systems

“…As described previously (10,16,17,26), a strong association of class 1 integrons (1,000, 1,000 and 1,200, and 1,600 bp) with identified resistance to specific antibiotics was demonstrated and attributed in part to the existence of resistance genes (aadA for streptomycin and spectinomycin, aadB for gentamicin and kanamycin, and ␤-lactamase for ampicillin) within these integrons. The gene sequencing and associated antibiotic resistance profiles of each integron group suggest that the 1,600-bp integron in part shares a common ancestor with the 1,000-bp integron plus additional genetic material containing the aadB gene.…”

“…The tetB gene, conferring resistance to tetracycline, is carried on the Tn10 transposon (14). Sulfisoxazole resistance carried by the sulI gene is part of the 3Ј conserved sequence (17), and chloramphenicol resistance, imparted by the S. enterica serovar Typhimurium flo gene, was not carried on integrons (1). The source of resistance to spectinomycin by isolates not carrying integrons is unknown.…”

“…Class 1 integrons can capture genes from the environment and incorporate them by site-specific recombination. When they are part of the genome of pathogenic organisms such as Salmonella (10,8,9,17), Klebsiella (13,26), Yersinia (23), and Escherichia coli (16), integrons may be responsible for the horizontal transfer of antibiotic resistance among other pathogenic bacteria. The presence of genes within integrons coding for antibiotic resistance and the association of antibiotic resistance phenotypes with the presence of integrons have been well documented (10,16,17,25,26).…”

Prevalence, assessment, and antimicrobial resistance patterns of Salmonella from raw chicken eggs in Haramaya, Ethiopia

“…The most common resistance was to streptomycin (75%), ampicillin (59.4%), tetracycline (46.9%), and spectinomycin (40.6%), which is in agreement with the present study. Miko et al [32] determined antimicrobial resistance of Salmonella serovars isolated from German foodstuff; they showed that the most prevalent resistance among the multidrug-resistant Salmonella serovars isolated from foods were to streptomycin (94%), sulfamethoxazole (92%), tetracycline (81%), ampicillin (73%), spectinomycin (72%), chloramphenicol (48%), and trimethoprim (27%). The result regarding nitrofurantoin with 50% resistance is in agreement with that of Tassios et al [33] in Brazil, who reported 57.82% resistance among Salmonella isolates.…”

Effects of sub-MIC antibiotic concentrations on biofilm production of Salmonella Infantis

“…Quinolones and fluoroquinolones are broad-spectrum antimicrobial agents that target DNA gyrase (gyrA and gyrB) and topoisomerase IV genes (parE and parC), and the resulting drug-enzyme-DNA complex inhibits DNA synthesis [13]. Mobile genetic elements such as plasmids, transposons, and the more recently explored integrons, which are able to disseminate antibiotic resistance genes by horizontal or vertical transfer, have played an important role in the evolution and dissemination of MDR in Gram-negative bacteria [20,21]. Further investigations are required to identify the genetic nature of antibiotic resistance of the 13 S. Infantis strains.…”