The occurrence of ant imicrobial resistance among the Salmonella serovar Stanley isolates from Thai patients differed according to the regional zones of isolation (Table 1). The highest levels of antimicrobial resistance were observed in isolates from zone 1, 4, and BKK; those isolates were resistant to up to 12 of the 17 tested antimicrobials,including extended-spectrum cephalosporins. In zone 4, 12 (80%) isolates were resistant to CTX and XNL,which represents the highest percentage of extended-spectrum cephalosporin-resistant isolates observed among the different regional zones (Table 1). In addition, one (25%) isolate (SH1796) from zone 5 showed reduced susceptibility to CIP (MIC 0.5 g/ml) and intermediate resistance to NAL (MIC 16 mg/liter) (Fig. 3, Table 1), thus displaying a phenotype compatible with the presence of PMQR genes. All Thai isolates were susceptible to APR,COL,NAL,and NEO (Table 1).