Table 3 Characteristics of MDR plasmids from 17 S. Braenderup isolates. Antimicrobial resistance gene Strains Plasmid RFLP
profile Antibiogram 1 aadA2 blaTEM blaCMY-2 Plasmid size (kb) Conjugation rate Inc 3 Class I integron IS 26 Month of isolation Number of isolates S. Braenderup 2 1a ACKTSSxt + + – 137.4 4.22 × 10-6 F1A/1B + ND INCB024360 manufacturer 2004.8 2 E. coli/p2 ACKSxtT + S. Braenderup 96 1a ACKSSxtT + + – 137.4 6.04 × 10-6 F1A/1B + ND 2004.8 E. coli/p96 ACKSxtT + S. Braenderup 24 1b ASSxt + + – 122.6 8.25 × 10-6 F1A/1B + ND 2004.8 1 E. coli/p24 ASxt + S. Braenderup 874 1d ASSxtT + + – 102.5 — F1A/1B + ND 2004.7 7 E. coli/p30 ASxt
+ S. Braenderup 12 1e ASSxtT + + – 99.1 – F1A/1B + ND 2005.4 3 E. coli/p12 ASxt + S. Braenderup 11 1g ASxtT – + – 104.4 – F1A/1B – ND 2005.1 1 E. coli/p11 ASxt + S. Braenderup 13 ACSSxtT + + + + ND 2004.7 E. coli/p13-1 A – - + 75.5 8.41 × 10-2 IncI1 – - 1 E. coli/p13-2 1f ACSxtT + + – 127.8 – F1A/1B + + 1 S. Braenderup 32 ASSxtT + + + + ND 2005.9 E. coli/p32-1 2a A – - + 75.5 8.66 × 10-2 IncI1 – - 1 E. coli/p32-2 1d ASxt + + – 102.5 ND F1A/1B + + 1 S. Braenderup 36 ASSxtT + + + + ND 2005.5 E. coli/36-1 2b A – - + 85 1.28 × 10-1 IncI1 – - 1 E. coli/p36-2 1c ASxt + + – 104.8 – F1A/1B + + 1 1Abbreviation: A, ampicillin; C, chloramphenicol; K, kanamycin; BYL719 chemical structure S, streptomycin; Sxt, trimethoprim-sulfamethoxazole; T, tetracycline. 2ND, not determined; +, conjugative; -, .non-conjugative. 3Inc, plasmid incompatibility group. 4Other 6 isolates 30 from 2005/2, Branched chain aminotransferase 31 from 2004/10, 35 from 2005/7, 37 from 2005/3, 44 from 2004/6, and 82 from 2004/7 were not tested for conjugation. 5Other 2 isolates 15 from 2005/5 and 21 from 2004/9 were not tested for conjugation. Figure 2 Hin dIII-digested RFLP profiles
of ampicillin resistance plasmids in S . Braenderup isolates. M1: HindIII-digested lambda DNA size marker. M2: 1 kb size marker. Figure 3 PCR amplification of IS 26 and IS 26 -associated DNA fragments. (A) Primer design. Symbols of arrow and dashed arrow represent IS26in primers and IS26out primers, respectively. (B) PCR products amplified by IS26in primers. (C) PCR products amplified by IS26out primers. M1: 100-bp size marker. N: negative control. M2: 1-kb size marker. Discussion Human salmonellosis was limited to five Salmonella serogroups: B, C1, C2-C3, D1, and E1 (Table 1). Despite the decrease in prevalence of S. Typhimurium and the increase in the prevalence of S. Enteritidis from 2005 to 2007, serogroups B and D Salmonellae were the major pathogens for foodborne salmonellosis in Taiwan due to S. Typhimurium, S. Stanley, and S. Enteritidis of serogroup D1 being the three most prevalent serovars overall.