Reference | Delsol_2003_JoofApMi (10278)

Eighteen piglets born from three litters of LargeWhite·Landrace cross and weaned at the age of 3 weekswere used in this study. The piglets were housed in a single group for4 weeks. They were then randomly separated into threepens with individual high efficiency particulate air filtrationin groups of six and fed in individual stalls twice daily forthe duration of the experiment. The feed used was astandard organic feed (grower/finisher pellets; Organic feedcompany, Thetford, UK). FiveS.Typhimurium DT104 strains were obtained fromthe culture collection at the Veterinary LaboratoriesAgency (VLA), Weybridge. Three of five strains were naturallyresistant to nalidixic acid, and the remaining two strainswere made resistant by passaging on nalidixic acid gradientplates. All five strains used to inoculate the pigs had a nalidixic acid minimal inhibitory concentration (MIC)value of 128 mg/l. Resistance to nalidixic acid waschosen as a selective marker for recovery from thebackground microflora. Forty-eight hours after inoculatingS. Typhimurium intothe pigs, one group was given a standard therapeutic dose (15 mg kg)1) of Aureomycin (Fort DodgeÒ; Southampton,UK), a second group was given a sub-therapeutic dose(1Æ5mgkg)1). Aureomycin was administered via the feed asrecommended by the manufacturer for 7 days. A thirdgroup acted as the control group and remained untreated.

Faecal samples were collected by digital manipulation 24 hafter the pigs were infected withS. Typhimurium DT104and on days 0, 1, 2, 4, 6 and 7 during treatment, and 1, 3,5, 7, 14, 18, 27 and 41 days post-treatment.

AST Method: Agar Dilution

Reference explicitly reports AST breakpoints: False

Reference reports using a MIC table: False