In vivo evaluation of mutant selection window of cefquinome against Escherichia coliin piglet tissue-cage model

BMC Veterinary Research

Table 2 Correlation of pharmacokinetic/pharmacodynamics (PK/PD) parameters with selection of resistance

PK/PD index, value ^a	Fraction of tissue-cages with resistant bacteria (mutant/total)	P ^b
T > MIC₉₉
≤25%	1/10	0.625
>25%	17/24	0.003
T > MPC
<50%	17/26	0.006
≥50%	1/8	0.400
AUC_{24 h}/MIC₉₉ (h)
≤32.84	1/8	0.571
32.84-125.64	16/20	0.001
≥125.64	1/6	0.500
AUC_{24 h}/MPC (h)
≤12.83	1/8	0.571
12.83-49.09	16/20	0.001
>49.09	1/6	0.500
C_max/MIC₉₉
≤1.32	1/9	0.600
1.32-4.26	16/18	0.0002
≥4.26	1/7	0.539
C_max/MPC
≤0.52	1/9	0.600
0.52-1.66	16/18	0.0002
≥1.66	1/7	0.539

All PK/PD parameters were determined using total drug concentrations in tissue cage fluid. Total 34 tissue cages were analyzed and 2 tissue cages excluded because of bacterial pollution.
^aTine in the window (T_msw) is not presented in the table because it fell into 2 categories.
^bP values were calculated by Fisher^’s exact test, with a set of 3 infected but untreated piglets (6 tissue-cages) used as a control. High values indicate no difference with the control.

ISSN: 1746-6148