Reference | Bauer.Garland_2006_JoofApMi (10358)

A total of 192 day-of-hatch broiler chicks from a commercial hatchery were randomly separated into two biosecure rooms with four pens in each room (12 birds in each pen). Two chicks in four of the pens were inoculated with a Salm. Typhimurium strain (8381r) resistant to 12 antimicrobials (including tetracycline), and two chicks in each of the four other pens were inoculated with a strain sensitive to all antimicrobials tested (8382s). The chicks were inoculated with 10^9 CFU/mL of 8381r or 8382s per os. Each room was exposed to either 8381r or 8382s. Two pens in each room received a constant dose of chlortetracycline in drinking water while the other two pens in each room received no antimicrobials, for a total of four treatments (8381r and 8382s with and without tet). The experiments were repeated twice, thus four replicates of each treatment were performed. Fresh water with or without tet was supplied daily. For chicks treated with tet, 120 ug of chlortetracycline per mL of water was added every 24 h according to the manufacturer’s directions for therapeutic dose of this antimicrobial in chickens. Inoculation was performed prior to the start of chlortetracycline treatment.

Uninoculated broiler chicks were killed by cervical dislocation and necropsied on day 7 postinoculation for examination of the caecum. A total of 1 g from the two caeca sampled was placed in bags with 50 ml of PBS.

AST Method: Broth Microdilution

Reference explicitly reports AST breakpoints: False

Reference reports using a MIC table: False