Table 2.

In vivo assessment of potential resistance to rifampicin, minocycline and/or chlorohexidine

Citation	Drug	Device: how is drug attached; concentration	Animal model species (n); implant site; duration	Organism(s) assessed	Methodology; resistance measurement	Results	After contact with the device, which of the following does the study show: (i) no change in resistance; or (ii) development of new resistance
Rifampicin (n = 3)
Avramovic et al., 199136	R	vascular graft; soaked in 100 mg aqueous R	sheep (20); carotid artery; 3 weeks	SA	Breakthrough ZOI; R antibiotic disc	All SA isolated from R-treated grafts remained sensitive	no change in resistance
Garrison et al., 199718	R	uncoated vascular graft; aqueous 4× and 1000× MIC R infused in subcutaneous pocket	mouse (42); subcutaneous pocket; 4, 18 and 42 h	SE	Biofilm eradication; MIC broth dilution	MIC of recovered SE from high-dose R increased from BL (0.1 to >30 mg/L)	development of new resistance
Sardelic et al., 199537	R	vascular graft; soaked in 1.2 mg/mL aqueous R	sheep (9); carotid artery; 3 weeks	MRSA	Breakthrough MIC; agar dilution	Breakthrough MRSA had same R MIC as starting inoculum	no change in resistance

ZOI, zone of inhibition; BL, baseline.