pharmacokinetic pharmacodynamic evaluation of the efficacy of flumequine in treating colibacillosis in turkeys

Abstract Flumequine (FLU) is used in the treatment of systemic bacterial infections in poultry, including colibacillosis, which is a common disease in turkeys. The pharmacokinetic (PK) behavior of FLU administered to 32 healthy turkeys as an oral bolus via gavage or as 10-h pulsed administration in drinking water were compared, using the authorized dose of 15 mg/kg and the double dose of 30 mg/kg. The minimum inhibitory concentrations (MIC) of 235 Escherichia coli field strains isolated from poultry were determined for pharmacodynamics (PD) to develop a PK/PD model. Blood samples were collected at established times over 24 h, and the obtained plasma was analyzed using a liquid chromatography tandem mass spectrometry method that was validated in-house. A monocompartmental model and a noncompartmental model were applied to the data to obtain the PK results. For both types of administration and both dosages, the ratios of the maximum concentration (Cmax)/MIC50 and the area under the plasma concentration-time curve (AUC)/MIC50 achieved were considerably lower than the fluoroquinolone breakpoints usually adopted for efficacy. The Cmax/MIC50 and AUC0–24/MIC50 ratios were, respectively, 0.67 ± 0.09 and 4.76 ± 0.48 and 1.18 ± 0.35 and 7.05 ± 2.40 for the 15 and 30 mg/kg bolus doses, respectively. After 10-h pulsed administration of 15 mg/kg, values of Cmax/MIC50, 0.19 ± 0.02 on d 1 and 0.30 ± 0.08 on d 5 of therapy were obtained, the AUC/MIC50 ratios were 2.09 ± 0.29 and 3.22 ± 0.93 on d 1 and 5, respectively. Higher values were obtained with the doubled dose of 30 mg/kg: the Cmax/MIC50 ratios were 0.49 ± 0.11 on d 1 and 0.69 ± 0.18 on d 5; the AUC/MIC50 ratios were 5.15 ± 1.15 and 6.57 ± 1.92 on d 1 and 5, respectively. Based on these results, FLU administration should be adopted when specific diagnostic findings indicate its efficacy, and revising the dosage scheme to comply with the prudent and responsible use of antimicrobials in veterinary medicine is advisable

Enrofloxacin against Escherichia coli in turkeys: Which treatment scheme is effective?

Abstract The efficacy of enrofloxacin (ENRO) was evaluated against multidrug-resistant avian pathogenic Escherichia coli correlating the minimum inhibitory concentrations (MIC) of 235 E. coli field strains with its pharmacokinetics (PK) in 50 healthy turkeys (5 groups) with a PK/pharmacodynamic approach. The treatments were as follows: a) single oral gavage and b) single subcutaneous (SC) treatment at the recommended dose of 10 mg/kg; c) single oral gavage, d) 5 d of 10-h pulsed water medication, and e) 5 d of 24-h continuous water medication at the doubled dose of 20 mg/kg. Blood samples were collected at established times over 24 h. Plasma was analyzed using a liquid chromatography tandem mass spectrometry method that was validated in house. A monocompartmental and a noncompartmental model were applied to the data to obtain the PK results. After gavage administration, the mean maximum concentration Cmax/MIC50 and area under the curve AUC0–24/MIC50 ratios were, respectively, 3.07 ± 0.62 and 7.01 ± 1.03 and 25.48 ± 3.04 and 57.2 ± 3.73 for the 10 and 20 mg/kg doses, respectively. After SC administration of 10 mg/kg, Cmax/MIC50 and AUC0–24/MIC50 ratios were 3.45 ± 0.75 and 33.96 ± 7.46, respectively. After the administration of 10-h pulsed or 24-h continuous medicated water at 20 mg/kg, lower values of Cmax/MIC50 (10-h pulsed: 3.45 ± 0.7; 24-h continuous: 3.05 ± 0.48) and AUC0–24/MIC50 (10-h pulsed: 42.42 ± 6.17; 24-h continuous: 53.32 ± 5.55) were obtained. Based on these results, the European Union-recommended dosage of 10 mg/kg seems ineffective to achieve adequate drug plasma concentrations and even the 20 mg/kg by 10 h pulsed or continuous medicated water administration did not reach completely efficacious concentrations in plasma against colibacillosis. Although the results obtained were not completely encouraging, the medicated water should preferably be provided continuously. To conclude about the efficacy of ENRO treatment against colibacillosis, target tissue concentration should be extensively considered

fluoroquinolone resistance and molecular characterization of gyra and parc quinolone resistance determining regions in escherichia coli isolated from poultry

Abstract Escherichia coli are a common inhabitant of the gastrointestinal tract of mammals and birds; nevertheless, they may be associated with a variety of severe and invasive infections. Whereas fluoroquinolones (FQ) have been banned in the United States for use in poultry production, the use of these antimicrobials in poultry husbandry is still possible in the European Union, although with some restrictions. The aim of this study was to investigate the FQ resistance of 235 E. coli isolates recovered from chickens and turkeys. Minimum inhibitory concentrations were determined by a microdilution method, whereas mutations in the quinolone resistance-determining regions of the target genes, gyrA and parC, were detected by a PCR-based method. High resistance rates (>60%) were observed for nalidixic acid, flumequine, and difloxacin, whereas resistance to ciprofloxacin, danofloxacin, enrofloxacin, marbofloxacin, and sarafloxacin was less frequently reported

The Potential Health Benefits of Polyphenol-Rich Extracts from Cichorium intybus

Phytochemicals can exert their bioactivity without reaching the systemic circulation; scarcely absorbed antioxidants might reach the large bowel contributing to protection from oxidative damage-induced gastrointestinal diseases. In the present work, we aimed to study the relationship between potential activity of polyphenol-rich extracts from Cichorium intybus L. and changes in morphological characteristics on Caco-2 cells. Phytochemicals content (carotenoids and flavonoids) and total antioxidant activity of Red Chicory of Treviso and Variegated Chicory of Castelfranco were evaluated. The bioactivity of polyphenol-rich extracts from chicories was studied in in vitro Caco-2 cell monolayers model. Morphological characteristics changes to test the antioxidant and/or prooxidant effect were verified by histological analysis and observed by Electronic Scansion Microscopy (SEM). On Caco-2 cell model, the polyphenols fractions from chicories have indicated a moderate antioxidant behavior until 17 μM concentration, while 70 μM and 34 μM exert cytotoxic effects for Treviso’s and Castelfranco’s Chicory, respectively, highlighted by TEER decreasing, increased permeability, and alteration of epithelium. Our findings support the beneficial effects of these products in counteracting the oxidative stress and cellular damage, induced in vitro on Caco-2 cell model, through interaction with the mucopolysaccharide complexes in the glycocalyx, maintaining in vivo a healthy and effective intestinal barrier

Plasma Procalcitonin Concentration in Healthy Horses and Horses Affected by Systemic Inflammatory Response Syndrome

The diseases most frequent associated with in adult horses are those involving the gastrointestinal tract. An early diagnosis should be the goal in the management of horses with . The objective of this study was to evaluate the plasma procalcitonin () concentration in healthy and horses to assess differences between the two groups. Seventy-eight horses (30 healthy and 48 ). Prospective in vivo multicentric study. Horses were classified as if at least 2 of the following criteria were met: abnormal leukocyte count or distribution, hyperthermia or hypothermia, tachycardia, tachypnea. Healthy horses showed no clinical or laboratory signs of . Plasma concentrations were measured with a commercial assay for equine species. Results were expressed as mean±standard deviation. T-test for unpaired data was performed between healthy and group. group was divided in 4 subgroups and t -test was performed between healthy versus each subgroup. concentrations in healthy and horses were 18.28 ± 20.32 and 197.0 ± 117.0 pg/, respectively. T-test showed statistical differences between healthy versus group and between healthy versus all subgroups. Results showed an increase in concentration in horses as previously reported in humans and dogs. could be used as a single assay in equine practice for detection of