TABLE 1.

Comparison of antibiotic resistance profiles of vegetative and swarm cells of serovar Typhimurium 14028

TargetGroupAntibiotic(s)MIC (μg/ml)a
VbSS/V ratio
Cell envelopeβ-LactamPenicillin G>32>32
Oxacillin>256>256
Ampicillin0.380.381
Amoxicillin111
Amoxicillin-clavulanic acid0.750.751
Piperacillin3165.3
Meropenem0.0470.255.3
Imipenem0.1250.1251
Ceftazidime0.2528
Phosphonate peptideFosfomycin441
Bacitracin>256>256
Colistin16966
Polymyxin241928
Protein synthesisMacrolideClarithromycin>256>256
Erythromycin>256>256
LincosamideClindamycin>256>256
AminoglycosideKanamycin12>256>21
Streptomycin12>256>21
Tobramycin6>256>42
Gentamicin3>256>85
TetracyclineDoxycycline1.521.3
Tetracycline0.50.51
DNA gyraseQuinoloneNalidixic acid2>256>128
Ciprofloxacin0.064693
RNA polymeraseAntimycobacterialRifampin6>256>42
MetabolismFolic acid antagonistTrimethoprim>32>32
  • a According to the instructions of the manufacturer, in situations where inhibition of growth occurred between two MICs, the higher value was declared the MIC. V, vegetative; S, swarm.

  • b Results from solid or swim plates; the plate with the higher MIC was chosen when the results were slightly different.