Badawy, E. S. A., A. M. Amer, G. M. Kamel, K. M. Eldeib, and P. D. Constable,
"Comparative pharmacokinetics using a microbiological assay and high performance liquid chromatography following intravenous administration of cefquinome in lactating goats with and without experimentally induced Staphylococcus aureus mastitis",
Small Ruminant Research, vol. 133, pp. 67 - 76, 2015.
AbstractAbstract Cefquinome pharmacokinetic values were compared using a microbiological assay (MA) and high performance liquid chromatography (HPLC) in lactating goats with and without experimentally induced Staphylococcus aureus mastitis. Five healthy lactating goats received an İV\} injection of cefquinome sulfate (75 mg, equivalent to cefquinome at 3.0 mg/kg BW). The same dose of cefquinome sulfate was administered İV\} after clinical mastitis was induced by intracisternal infusion of 100 cfu of S. aureus \{ATCC\} 29213. Jugular venous blood and milk samples were obtained periodically after cefquinome administration in healthy and mastitic goats, and plasma and skimmed milk cefquinome concentrations were determined using \{MA\} and HPLC. Deming regression and Bland-Altman plots indicated equivalence of \{MA\} and HPLC. Both \{MA\} and \{HPLC\} analytical methodologies yielded statistically similar mean values for the cefquinome concentration-time relationship in plasma and skimmed milk and similar values for almost all calculated pharmacokinetic indices; however, \{HPLC\} had a lower limit of quantification \{LOQ\} and coefficient of variation, and a higher correlation coefficient for standard curves. Noncompartmental pharmacokinetic (PK) analysis indicated that mastitis decreased the mean residence time of cefquinome in plasma but did not change the mean residence time in skimmed milk. Skimmed milk cefquinome concentrations after İV\} injection remained below the \{MIC\} (0.25 ?g/mL) for S. aureus at every measurement time except at 6 h after injection, and clinical mastitis remained present for at least 5 days in treated goats. In conclusion, \{MA\} provides a simple, practical and inexpensive method for measuring cefquinome concentrations in plasma and skimmed milk samples from goats, while, \{HPLC\} proved to be more sensitive, specific and accurate. Mastitis increased cefquinome clearance compared to healthy goats which emphasizes the importance of performing pharmacokinetic studies in infected animals. Additional studies are required to determine whether intramammary cefquinome is effective in treating S. aureus mastitis in goats.