TY - JOUR
T1 - Establishing streptomycin epidemiological cut-off values for Salmonella and Escherichia coli. Microbial Drug Resistance
AU - Garcia-Migura, L.
AU - Sunde, M.
AU - Karlsmose, S.
AU - Veldman, K.T.
AU - Schroeter, A.
AU - Guerra, B.
AU - Granier, S.A.
AU - Perrin-Guyomard, A.
AU - Gicquel-Bruneau, M.
AU - Franco, A.
AU - Englund, S.
AU - Teale, C.
AU - Heiska, H.
AU - Clemente, L.
AU - Boerlin, P.
AU - Moreno, M.A.
AU - Daignault, D.
AU - Mevius, D.J.
AU - Hendriksen, R.S.
AU - Aarestrup, F.M.
PY - 2012
Y1 - 2012
N2 - This study was conducted to elucidate the accuracy of the current streptomycin epidemiological cut-off value (ECOFF) for Escherichia coli and Salmonella spp. A total of 236 Salmonella enterica and 208 E. coli isolates exhibiting MICs between 4 and 32¿mg/L were selected from 12 countries. Isolates were investigated by polymerase chain reaction for aadA, strA, and strB streptomycin resistance genes. Out of 236 Salmonella isolates, 32 (13.5%) yielded amplicons for aadA (n¿=¿23), strA (n¿=¿9), and strB (n¿=¿11). None of the 60 Salmonella isolates exhibiting MIC 4¿mg/L harbored resistance genes. Of the Salmonella isolates exhibiting MICs 8¿mg/L, 16¿mg/L, and 32¿mg/L, 1.6%, 15%, and 39%, respectively, tested positive for one or more genes. For most monitoring programs, the streptomycin ECOFF for Salmonella is wild type (WT) =32 or =16¿mg/L. A cut-off value of WT =32¿mg/L would have misclassified 13.5% of the strains as belonging to the WT population, since this proportion of strains harbored resistance genes and exhibited MICs =32¿mg/L. Out of 208 E. coli strains, 80 (38.5%) tested positive for aadA (n¿=¿69), strA (n¿=¿18), and strB (n¿=¿31). Of the E. coli isolates exhibiting MICs of 4¿mg/L, 8¿mg/L, 16¿mg/L, and 32¿mg/L, 3.6%, 17.6%, 53%, and 82.3%, respectively, harbored any of the three genes. Based on the European Committee on Antimicrobial Susceptibility Testing guidelines (ECOFF =16¿mg/L), 25% of the E. coli strains presenting MIC =16¿mg/L would have been incorrectly categorized as belonging to the WT population. The authors recommend an ECOFF value of WT =16¿mg/L for Salmonella and WT =8¿mg/L for E. coli.
AB - This study was conducted to elucidate the accuracy of the current streptomycin epidemiological cut-off value (ECOFF) for Escherichia coli and Salmonella spp. A total of 236 Salmonella enterica and 208 E. coli isolates exhibiting MICs between 4 and 32¿mg/L were selected from 12 countries. Isolates were investigated by polymerase chain reaction for aadA, strA, and strB streptomycin resistance genes. Out of 236 Salmonella isolates, 32 (13.5%) yielded amplicons for aadA (n¿=¿23), strA (n¿=¿9), and strB (n¿=¿11). None of the 60 Salmonella isolates exhibiting MIC 4¿mg/L harbored resistance genes. Of the Salmonella isolates exhibiting MICs 8¿mg/L, 16¿mg/L, and 32¿mg/L, 1.6%, 15%, and 39%, respectively, tested positive for one or more genes. For most monitoring programs, the streptomycin ECOFF for Salmonella is wild type (WT) =32 or =16¿mg/L. A cut-off value of WT =32¿mg/L would have misclassified 13.5% of the strains as belonging to the WT population, since this proportion of strains harbored resistance genes and exhibited MICs =32¿mg/L. Out of 208 E. coli strains, 80 (38.5%) tested positive for aadA (n¿=¿69), strA (n¿=¿18), and strB (n¿=¿31). Of the E. coli isolates exhibiting MICs of 4¿mg/L, 8¿mg/L, 16¿mg/L, and 32¿mg/L, 3.6%, 17.6%, 53%, and 82.3%, respectively, harbored any of the three genes. Based on the European Committee on Antimicrobial Susceptibility Testing guidelines (ECOFF =16¿mg/L), 25% of the E. coli strains presenting MIC =16¿mg/L would have been incorrectly categorized as belonging to the WT population. The authors recommend an ECOFF value of WT =16¿mg/L for Salmonella and WT =8¿mg/L for E. coli.
KW - antimicrobial susceptibility
KW - resistance genes
KW - food animals
KW - protein s12
KW - integrons
KW - bacteria
KW - typhimurium
KW - countries
KW - products
KW - class-1
U2 - 10.1089/mdr.2011.0064
DO - 10.1089/mdr.2011.0064
M3 - Article
VL - 18
SP - 88
EP - 93
JO - Microbial Drug Resistance-Mechanisms Epidemiology and Disease
JF - Microbial Drug Resistance-Mechanisms Epidemiology and Disease
SN - 1076-6294
IS - 1
ER -