FIG 3 .

Effect of antibiotics on swimming and swarming motility in an antibiotic-sensitive isolate of Salmonella. Chloramphenicol, tetracycline, streptomycin, and kanamycin were added at various subinhibitory concentrations to swimming and swarming agar media to determine their effect on motility in the antibiotic-sensitive S. Typhimurium isolate SARB65. Growth was normalized to the no-antibiotic control for each isolate, and data were expressed as a fold change for all pairwise comparisons for each antibiotic and motility combination. Statistical differences are noted by letters (P < 0.05), where any pairwise combination that shares the same letter is not considered different.