Pharmacokinetics and bioavailability of cefquinome in crossbred wild boars

Pharmacokinetics and relative bioavailability study of two cefquinome sulfate intramammary infusions in cow milk

In this study, two intramammary infusions of cefquinome sulfate were investigated for pharmacokinetics and bioavailability. Twelve lactating cows for each group were administered an effective dose of 75 mg/gland for cefquinome, with milk samples collected at various time intervals. The concentrations of cefquinome in milk at different times were determined by the UPLC-MS/MS method. Analyses of noncompartmental pharmacokinetics were conducted on the concentration of cefquinome in milk. Mean pharmacokinetic parameters of group A and group B following intramammary administration were as follows: AUClast 300558.57 ± 25052.78 ng/mL and 266551.3 ± 50654.85 ng/mL, Cmax 51786.35 ± 11948.4 ng/mL and 59763.7 ± 8403.2 ng/mL, T1/2 5.69 ± 0.62 h and 5.25 ± 1.62 h, MRT 7.43 ± 0.79 h and 4.8 ± 0.78 h, respectively. Pharmacokinetic experiments showed that the relative bioavailability of group B was 88.69% that of group A. From our findings, group B (3 g: 75 mg) shows a quicker drug elimination process than group A (8 g: 75 mg), which suggests that the withdrawal period for the new formulation may be shorter.

RNA-seq-based transcriptome analysis of a cefquinome-treated, highly resistant, and virulent MRSA strain

The emergence and dissemination of methicillin-resistant Staphylococcus aureus (MRSA) strains of animal origin that are resistant to several antibiotics is of great concern. Cefquinome is a fourth-generation cephalosporin developed specifically for veterinary use. The mechanism of MRSA resistance to cefquinome is still not established. Therefore, we designed this study to evaluate the effect of cefquinome on the transcriptome of MRSA1679a, a strain that was isolated from a chicken. The transcriptome analysis indicated that multiple efflux pumps (QacA, NorB, Bcr, and ABCb) were upregulated in MRSA1679a as a resistance mechanism to expel cefquinome. Additionally, penicillin-binding protein 1A was overexpressed, which conferred resistance to cefquinome, a β-lactam antibiotic. Adhesion and the biofilm-forming capacity of the MRSA strain was also enhanced in addition to overexpression of many stress-related genes. Genes related to carbohydrate metabolism, secretion systems, and transport activity were also significantly upregulated in MRSA1679a. In conclusion, global transcription was triggered to overcome the stress induced by cefquinome, and the MRSA1679a showed a great genetic potential to survive in this challenging environment. This study provides a profound understanding of MRSA1679a as a potentially important pathogen and identifies key resistance characteristics of MRSA against cefquinome. Studies should be aimed to demonstrate multidrug resistance mechanisms of virulent strains by exposing to different antibiotic combinations.

Pharmacokinetics, bioavailability and dose assessment of Cefquinome against Escherichia coli in black swans (Cygnus atratus)

BACKGROUND

The objective of this study is to investigate pharmacokinetics and dose regimens of cefquinome in black swans following intravenous (IV) and intramuscular (IM) administration at a single dose of 2 mg/kg. The MICs of cefquinome against 49 Escherichia coli isolates from black swans were determined. Monte Carlo simulation was applied to conduct the dose regimen assessment and optimization of cefquinome against E. coli in black swans, and a pharmacokinetic/pharmacodynamic (PK/PD) cutoff was established for E. coli isolates obtained in this study.

RESULTS

The PK parameters of T_1/2α (0.31 h), T_1/2β (1.69 h) and Cl_B (0.13 L/kg·h) indicated a rapid distribution and elimination of cefquinome in black swans after IV administration. After IM injection, the corresponding PK parameters of T_1/2Ka, T_1/2Ke, T_max, C_max, and F were 0.12 h, 1.62 h, 0.39 h, 5.71 μg/mL and 74.2%, respectively. The MICs of cefquinome against black swans E. coli ranged from 0.03 to 8 μg/mL, with MIC₅₀ and MIC₉₀ of 0.06 and 0.5 μg/mL, respectively. The PK/PD cutoff of cefquinome against E. coli was determined to be 0.2 μg/mL. Monte Carlo simulation showed that the nominal dose regimen (2 mg/kg/24 h) could not achieve a satisfactory probability of target attainment (PTA) for %T_MIC ≥ 50%, indicating a risk of treatment failure and the development of potential drug resistance.

CONCLUSIONS

The current daily dosage of cefquinome when divided into 12-h interval (1 mg/kg/12 h) may be effective for the treatment of E. coli infections with an MIC ≤0.5 μg/mL.

Integration of PK/PD for dose optimization of Cefquinome against Staphylococcus aureus causing septicemia in cattle

Cefquinome is a fourth generation cephalosporin with antimicrobial activity against gram negative and gram positive bacterial species, including Staphylococcus aureus. The aim of our study was to observe the ex-vivo activity of cefquinome against Staphylococcus aureus strains by using bovine serum from intravenously treated cattle. Cefquinome kinetics were measured by liquid chromatography and UV detection. In vitro post antibiotic effects (PAEs) and mutant prevention concentrations were determined with S. aureus strain ATCC 12598. Cefquinome exhibited time-dependent killing and produced in vitro PAEs increasing with concentration and time of exposure. A pharmacokinetic-pharmacodynamic model was established to simulate the efficacy of cefquinome for different dosage regimens. A dosage of 2 mg/kg every 12 h for 3 days was expected to reach a bactericidal activity against S. aureus in case of septicemia.

Pharmacokinetics of cefquinome in tilapia (Oreochromis niloticus) after a single intramuscular or intraperitoneal administration

The pharmacokinetics of cefquinome was studied in plasma after a single dose (10 mg/kg) of intramuscular (i.m.) or intraperitoneal (i.p.) administration to tilapia (Oreochromis niloticus) in freshwater at 30 °C. Ten fish per sampling point were examined after treatment. The data were fitted to two-compartment open models following both routes of administration. The estimates of total body clearance (CL/F), volume of distribution (Vd/F), and absorption half-life (T1/2ka ) were 0.049 and 0.037 L/h/kg, 0.41 and 0.33 L/kg, and 0.028 and 0.035 h following i.m. and i.p. administration, respectively. After i.m. injection, the elimination half-life (T1⁄2β ) was calculated to be 5.81 h, the maximum plasma concentration (Cmax ) to be 49.40 μg/mL, the time to peak plasma cefquinome concentration (Tmax ) to be 0.14 h, and the area under the plasma concentration-time curve (AUC) to be 204.6 μg h/mL. Following i.p. administration, the corresponding estimates were 6.05 h, 44.39 μg/mL, 0.17 h and 267.8 μg h/mL. The minimum inhibitory concentrations of cefquinome, determined for 30 strains of Streptococcus agalactiae isolated from diseased tilapia, ranged from 0.015 to 0.12 μg/mL. Results from these studies support that 10 mg cefquinome/kg body weight daily could be expected to control tilapia bacterial pathogens inhibited in vitro by a minimal inhibitory concentration value of ≤2 μg/mL.

Pharmacokinetic/pharmacodynamic relationship of cefquinome against Pasteurella multocida in a tissue-cage model in yellow cattle

The cephalosporin antimicrobial drug cefquinome was administered to yellow cattle intravenously (i.v.) and intramuscularly (i.m.) at a dose of 1 mg/kg of body weight in a two-period crossover study. The pharmacokinetic (PK) properties of cefquinome in serum, inflamed tissue-cage fluid (exudate), and noninflamed tissue-cage fluid (transudate) were studied using a tissue-cage model. The in vitro and ex vivo activities of cefquinome in serum, exudate, and transudate against a pathogenic strain of Pasteurella multocida (P. multocida) were determined. A concentration-independent antimicrobial activity of cefquinome was confirmed for levels lower than 4 × MIC. Integration of in vivo pharmacokinetic data with the in vitro MIC provided mean values for the time that drug levels remain above the MIC (T > MIC) in serum was 14.10 h after intravenous and 14.46 h after intramuscular dosing, indicating a likely high level of effectiveness in clinical infections caused by P. multocida of MIC 0.04 μg/mL or less. These data may be used as a rational basis for setting dosing schedules, which optimize clinical efficacy and minimize the opportunities for emergence of resistant organisms.

Population pharmacokinetics of cefquinome in pigs

This study was performed in 145 pigs to develop a population pharmacokinetics (PPK) model by i.m. administration of cefquinome (CEQ) at the dose of 2 mg/kg in the neck muscle. Serum physiological and biochemical parameters for each pig were determined before administration. After administration, 2-4 samples were collected at random, with the sampling point evenly distributed in the three periods (<1 h, 1-4 h and >4 h). The plasma concentration of CEQ was determined by high performance liquid chromatography with UV detector. The pharmacostatistical analyses of concentration-time data, weight, age, gender, serum physiological and biochemical parameters were performed with nonlinear mixed effect modeling (NONMEM). A one-compartmental model with first-order absorption and elimination adequately described the data from the study group. The optimal random effect model of pharmacokinetics parameters was of log-normal distribution and the residual errors assumed a mixed-type model (proportional and additive) to best explain intra-individual variability. Covariate analysis showed that body weight is positively correlated with apparent volume of distribution (V/F) and body clearance (CL/F). The typical PPK parameters of Ka , CL, and V were 0.564/h, 5.15 L/h, and 1.36 L, respectively.