Table 2.

Relations between IPs, amplicon sizes, resistance genes, and resistance patterns found within Salmonella serotypes

IP: amplicon size/resistance geneTypes of resistanceaSerotype (no. of strains)Isolation period
I: 1,000-bp/aadA2; 1,200-bp/pse-1 SUL-STR-SPT-AMP-CHL-TET (NAL; CEF; SXT)Typhimurium (30)b,c 1991–1998
II: 1,000-bp/aadA1a SUL-STR-SPT-CHL-SXT (AMP; CEF; GEN; KAN; TET)Virchow (4)1992–1994
SUL-STR-SPT-CHL-GEN (AMP; KAN; NAL; TET)Typhimurium (2)1992–1998
SUL-STR-SPT-CHL-KAN-SXT-TETWorthington (2)1993
SUL-STR-SPT-NAL-SXT-TETPanama (1)c 1995
SUL-STR-SPT-GEN-TETPoona (1)1996
SUL-STR-SPT-AMP-GENEnteritidis (1)1998
SUL-STR-SPTHadar (1)1998
IIIa: 1,600-bp/dfrA14-aadA1a SUL-STR-SPT-AMP-CEF-CHL-KAN-SXT-TETTyphimurium (1)1989
IIIb: 1,600-bp/dfrA1-aadA1a SUL-STR-SPT-KAN-SXT-TET (AMP; CEF; NAL)Panama (9)1996–1998
SUL-STR-SPT-SXT-TET (AMP; CHL; KAN)Ohio (5)1996–1998
SUL-STR-SPT-AMP-CHL-KAN-SXTBrandenburg (1)1996
IV: 2,000-bp/oxa1-aadA1a SUL-STR-SPT-AMP-CHL-TET (GEN; SXT)Typhimurium (5)1993–1998
V: 2,300-bp/sat1-aadA1a SUL-STR-SPT-AMP-CHL-KANVirchow (3)1992–1994
  • a Additional types of resistance found in some but not all of the strains of the serotype are indicated by parentheses. Drug abbreviations are defined in Table 1, footnotea.

  • b Food strains are also included.

  • c Sewage strains are also included.