Antimicrobials used in poultry production have the potential to bioaccumulate in poultry feathers but available data are scarce. Although feathers were processed and introduced as a protein source in animal feed, withdrawal periods were not established. Hence, an experimental trial was conducted to evaluate the residuol profile of enrofloxacin and its primary metabolite ciprofloxacin in featherof broiler chicken. Thirty six one-day old broiler chicks were randomly divided into control (6 nos) and treatment group (30 nos). Treatment group was administered with enrofloxacin at recommended therapeutic dose 10 mg Kg , through drinking water for five consecutive days from 43rd  to 47th -1 day of age, whereas control group received non-medicated water. Six birds from treatment group were sacrificed ethically and feather samples were collected at different time points during the withdrawal period at 48 hours interval on day 1, 3, 5, 7 and 9 post treatment. Control birds were sacrificed on day 9 post treatment. Enrofloxacin and ciprofloxacin residues in feather were analysed by a validated High Performance Thin Layer Chromatography Fluorescent Densitometry method. The present study revealed that enrofloxacin persisted in feather throughout the study period, where as its metabolite ciprofloxacincould be detected until 7th day post treatment and on 9th day post treatment it was below detection limit. The interesting finding is the high level of enrofloxacin achieved in feathers during the withdrawal period. Drug withdrawal times, based on the concentrations of antimicrobial residues in edible chicken meat, were not adequate to reduce antimicrobial residues in chicken feathers. As the feathers are used as a protein source to supplement feed for different food animal species (bovines, pigs, Salmons, trouts) they must be considered potential reservoirs of chemical residues that can reach man through the food chain; hence, the present study warrantsestablishment of withdrawal period for feather similar to that of edible tissues. 

Antimicrobials used in poultry production have the potential to bioaccumulate in poultry feathers but available data are scarce. Although feathers were processed and introduced as a protein source in animal feed, withdrawal periods were not established. Hence, an experimental trial was conducted to evaluate the residuol profile of enrofloxacin and its primary metabolite ciprofloxacin in featherof broiler chicken. Thirty six one-day old broiler chicks were randomly divided into control (6 nos) and treatment group (30 nos). Treatment group was administered with enrofloxacin at recommended therapeutic dose 10 mg Kg , through drinking water for five consecutive days from 43rd  to 47th -1 day of age, whereas control group received non-medicated water. Six birds from treatment group were sacrificed ethically and feather samples were collected at different time points during the withdrawal period at 48 hours interval on day 1, 3, 5, 7 and 9 post treatment. Control birds were sacrificed on day 9 post treatment. Enrofloxacin and ciprofloxacin residues in feather were analysed by a validated High Performance Thin Layer Chromatography Fluorescent Densitometry method. The present study revealed that enrofloxacin persisted in feather throughout the study period, where as its metabolite ciprofloxacincould be detected until 7th day post treatment and on 9th day post treatment it was below detection limit. The interesting finding is the high level of enrofloxacin achieved in feathers during the withdrawal period. Drug withdrawal times, based on the concentrations of antimicrobial residues in edible chicken meat, were not adequate to reduce antimicrobial residues in chicken feathers. As the feathers are used as a protein source to supplement feed for different food animal species (bovines, pigs, Salmons, trouts) they must be considered potential reservoirs of chemical residues that can reach man through the food chain; hence, the present study warrantsestablishment of withdrawal period for feather similar to that of edible tissues. 

The aim of this study was to evaluate the occurrence of Shiga toxin (stx)-producing Escherichia coli (STEC) in diarrheic newborn calves, as well as the resistance profile of this microorganism against antimicrobials routinely used in veterinary therapy. The antimicrobial profile of Eugenia uniflora against E. coli clinical isolates was also analyzed. Specimens from the recto-anal junction mucosa were investigated by using chromogenic medium and identification of E. coli was done using microbiological methods (Gram staining, indole test, methyl red test, Voges-Proskauer test, citrate test, urease test, and hydrogen sulfide test). The stx1 and stx2 genes corresponding to the STEC pathotype were evaluated by using polymerase chain reaction and electrophoresis. The susceptibility profile to antimicrobial agents commonly used in veterinary therapeutic practice and the antimicrobial effect of lyophilized hydroalcoholic extract of E. uniflora L. leaves against E. coli clinical isolates were evaluated by disk diffusion and microdilution methods. Shiga toxin-positive E. coli was identified in 45% of diarrheic newborn calves (stx1 = 23.2%, stx2 = 4.0%, stx1 + stx2 = 18.2%). The frequency of stx-positive E. coli in the bacterial population was equal to 17.0% (168/990 clinical isolates): 97 (9.8%) stx1-positive E. coli, 12 (1.2%) stx2-positive E. coli, and 59 (6.0%) stx1 + stx2-positive E. coli isolates. All stx-positive E. coli analyzed showed resistance to multiple drugs, that is, from 4 to 10 antimicrobials per clinical isolate (streptomycin, tetracycline, cephalothin, ampicillin, sulfamethoxazole + trimethoprim, nitrofurantoin and nalidixic acid, ciprofloxacin, gentamicin, and chloramphenicol). Effective management measures should be implemented, including clinical and laboratory monitoring, in order to promote animal and worker health and welfare, prevent and control the spread of diseases, and ensure effective treatment of infectious diseases. The E. uniflora L. leaves showed inhibition of microbial growth based on the diameter of halos, ranging from 7.9 to 8.0 mm and 9.9 to 10.1 mm for concentrations of 50 and 150 mg/mL, respectively. This plant displayed bacteriostatic action and a minimum inhibitory concentration of 12.5 mg/mL for all clinical isolates. Its clinical or synergistic effects with antimicrobial agents must be determined from clinical and preclinical trials.

The present study aimed to investigate the prevalence of Salmonella and their antibiotic resistance pattern against two commonly used antibiotics: ciprofloxacin and ceftriaxone in marketed live chickens in a live birds market. Materials and methods: The study was conducted on live Sonali chickens (crossbred of Fayoumi female and Rhode Island Red male). Cloacal swabs were collected from 50 randomly selected live birds from 5 retail sellers (10 samples/seller) at Jhawtola live birds’ market, Chattogram, Bangladesh. Culture and biochemical tests were used to identify Salmonella. Positives samples for Salmonella were further tested for antibiogram by disc diffusion method.Salmonella was identified from 28 (56%) of samples by culture and biochemical test. Among the positive isolates, 27 (96.42%) samples exhibited resistant to ceftriaxone, and 20 (71.42%) samples were to ciprofloxacin.The result of this study indicates there is a high prevalence of Salmonella in marketed local chicken and are resistant to ceftriaxone and ciprofloxacin which has economic importance as well as a public health concern. Awareness should be increased to prevent random use of antibiotics and provision of strict biosecurity measures.

Objective: To determine the pharmacokinetics of ciprofloxacin in dogs, including oral absorption following administration of generic ciprofloxacin tablets. Animals: 6 healthy Beagles. Procedures: In a crossover study design, ciprofloxacin was administered as a generic tablet (250 mg, PO; mean dose, 23 mg/kg) and solution (10 mg/kg, IV) to 6 dogs. In a separate experiment, 4 of the dogs received ciprofloxacin solution (10 mg/mL) PO via stomach tube (total dose, 250 mg). Blood samples were collected before (time 0) and for 24 hours after each dose. Plasma concentrations were analyzed with high-pressure liquid chromatography. Pharmacokinetic analysis was performed by means of compartmental modeling. Results: When ciprofloxacin was administered as tablets PO, peak plasma concentration was 4.4 μg/mL (coefficient of variation [CV], 55.9%), terminal half-life (t1/2) was 2.6 hours (CV, 10.8%), area under the time-concentration curve was 22.5 μg•h/mL (CV, 62.3%), and systemic absorption was 58.4% (CV, 45.4%). For the dose administered IV, t1/2 was 3.7 hours (CV, 52.3%), clearance was 0.588 L/kg/h (CV, 33.9%), and volume of distribution was 2.39 L/kg (CV, 23.7%). After PO administration as a solution versus IV administration, plasma concentrations were more uniform and consistent among dogs, with absorption of 71% (CV, 7.3%), t1/2 of 3.1 hours (CV, 18.6%), and peak plasma concentration of 4.67 μg/mL (CV, 17.6%). Conclusions and Clinical Relevance: Inconsistent oral absorption of ciprofloxacin in some dogs may be formulation dependent and affected by tablet dissolution in the small intestine. Because of the wide range in oral absorption of tablets, the dose needed to reach the pharmacokinetic-pharmacodynamic target concentration in this study ranged from 12 to 52 mg/kg (CV, 102%), with a mean dose of 25 mg/kg, once daily, for bacteria with a minimum inhibitory concentration ≤ 0.25 μg/mL.

The pharmacokinetic properties of enrofloxacin were determined in broiler chickens after single IV and orally administered doses of 10 mg/kg of body weight. After IV and oral administrations, the plasma concentration-time graph was characteristic of a two-compartment open model. The elimination half-life and the mean +/- SEM residence time of enrofloxacin for plasma were 10.29 +/- 0.45 and 9.65 +/- 0.48 hours, respectively, after IV administration and 14.23 +/- 0.46 and 15.30 +/- 0.53 hours, respectively, after oral administration. After single oral administration, enrofloxacin was absorbed slowly, with time to reach maximal plasma concentration of 1.64 +/- 0.04 hours. Maximal plasma concentration was 2.44 +/- 0.06 micrograms/ml. Oral bioavailability was found to be 64.0 +/- 0.9%. Statistically significant differences between the routes of administration were found for the pharmacokinetic variables-half-lives of the distribution and elimination phase and apparent volume of distribution and volume of distribution at steady state. In chickens, enrofloxacin was extensively metabolized into ciprofloxacin. Residues of enrofloxacin and the major metabolite ciprofloxacin in fat, kidney, liver, lungs, muscles, and skin were measured in chickens that received an orally administered dose of 10 mg/kg once daily for 4 days. The results indicate that enrofloxacin and ciprofloxacin residues were cleared slowly. Mean muscle, liver, and kidney concentrations of the metabolite ciprofloxacin ranging between 0.020 and 0.075 micrograms/g persisted on day 12 in chickens after dosing. However, at the time of slaughter (12 days), enrofloxacin residues were only detected in liver and mean +/- SEM concentration was 0.025 +/- 0.003 micrograms/g.