Table 1.

Frequency of antimicrobial resistance in differentSalmonella serotypes

SerotypeNo. of strains tested% Resistance within serotype to antimicrobial agenta:
AMPCEFCHLGENKANNALSTRSPTSULSXTTET
Typhimurium837786464176954933189
Enteritidis64280330616316317
Virchow4925616612202420391024
Hadar339003021483021333
Ohio32250313603834471931
Panama3023027030773733433343
Muenchen16000006000013
Otherb 3590116992014431423
Total3423432257183727461642
  • a Drugs and disk loads were as follows: ampicillin (AMP), 10 μg; cephalothin (CEF), 30 μg; chloramphenicol (CHL), 30 μg; gentamicin (GEN), 10 μg; kanamycin (KAN), 30 μg; nalidixic acid (NAL), 30 μg; streptomycin (STR), 10 μg; spectinomycin (SPT), 10 μg; sulfadiazine (SUL), 300 μg; trimethoprim-sulfamethoxazole (SXT), 1.25 and 23.75 μg, respectively; and tetracycline (TET), 30 μg. Also tested were amikacin (30 μg), ceftazidime (30 μg), ciprofloxacin (5 μg), and imipenem (10 μg), all strains being susceptible.

  • b Other serotypes include Infantis (seven strains), Bredeney (six strains), Brandenburg (five strains), Derby (five strains), Newport (three strains), Worthington (three strains), Grumpensis (two strains), Agona (one strain), Havana (one strain), Ndolo (one strain), and Poona (one strain).