Evolution of antibacterial multiresistance in non-typhoidal Salmonella serovars in Argentina.?h

CENTRON DANIELA

Molecular biology and molecular epidemiology of Salmonella infections?h

Juan J. Calva y Edmundo Calva, eds.

Lugar: New Delhi; Año: 2009; p. 161 - 175

Genetic elements that are usually involved in lateral DNA gene transfer are playing a main role on genomic evolution of multidrug resistance isolates, in non-typhoidal Salmonella nosocomial isolates from Argentina. Progressive acquisiton of plasmid-mediated resistance determinants has been detected since 1984. Furthermore, accumulation of five β-lactamase genes, blaCTX-M-2, blaOXA-9, blaOXA-2,blaTEM-1, and blaPER-2, class 1 and 2 integrons as well as transposons such as Tn1331 and Tn9 are usually harbored in several isolates. Experimental data has suggested that antimicrobial resistance mechanisms in these bacteria may have been the consequence of plasmid exchange between Salmonella enterica serovar Typhimurium and Escherichia coli or Shigella flexneri or due to the spreading of mobile elements from the nosocomial environment, or both. Hence, the control of infections in our country must be focused on the spreading of plasmid-mediated determinants such as blaIMP-like, blaVIM-like, aac(6´)-Ib-cr and qnrB10 genes, that have been found in other gram-negative bacilli from clinical samples in Argentinean hospitals, and therefore, could be transferred to non-typhoidal Salmonella isolates.