Pharmacokinetics of voriconazole after a single intramuscular injection in large falcons (Falco spp.).

Voriconazole is one of the main azoles used to treat invasive aspergillosis in falconry raptors and birds. Despite the fact that there are studies for oral and intravenous use of voriconazole in birds, there are none for its effect after intramuscular use. Empirical use of intramuscular voriconazole in falcons, indicated quicker therapy response than the oral one. Aim of this study is to evaluate the in vivo pharmacokinetic disposition of injectable voriconazole after a single intramuscular injection in large falcons (i.e., Gyrfalcons, Saker falcons, Peregrine falcons). No clinical side effects were observed in the falcons. Absorption of voriconazole was rapid (0.5-2 hours) and reached a plasma level (>1 µg/ml) which is above the minimal inhibitory concentration (MIC) for all known Aspergillus strains. This level was maintained for 16 to 20 hours, thus indicating that a single injection of 12.5 mg/kg is not enough if T > MIC is taken into consideration. On a newer aspect, according to the AUC24 unbound: MIC parameter would be indicated that this dose would be rather sufficient for most Aspergillus strains.

Susceptibility of fungi isolated from the respiratory tract of falcons to amphotericin B, itraconazole and voriconazole.

The minimum inhibitory concentrations (mics) of fungi isolated from the air sacs of falcons before (group 1), and during antifungal treatment with amphotericin B nebulisation and oral itraconazole or voriconazole (group 2), or with itraconazole alone (group 3) or voriconazole alone (group 4) were determined. Before treatment, 95 per cent of the isolates, including Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger and Aspergillus terreus, were susceptible to voriconazole at mics up to 0.38 microg/ml, and all the isolates were susceptible at mics up to 1 microg/ml. Before treatment, 21 per cent of the isolates, including A fumigatus (27.6 per cent), A flavus (16.6 per cent), A niger (100 per cent) and A terreus (23 per cent), were resistant (mic > or =1 microg/ml) to itraconazole; 51 per cent of the isolates, including A fumigatus (31 per cent), A flavus (78 per cent), A niger (14 per cent) and A terreus (77 per cent), had mics of over 1 microg/ml to amphotericin B, and after treatment their mics increased significantly. In contrast, there were no significant differences between the mics of voriconazole and itraconazole for the different Aspergillus species before and during treatment with these antifungal agents.

Assessment of a commercial sandwich ELISA in the diagnosis of aspergillosis in falcons.

A commercial sandwich elisa (Platelia Aspergillus EIA; Bio-Rad) developed for the detection of galactomannan, a major cell wall constituent of Aspergillus species, was tested for its efficacy in the diagnosis of aspergillosis in falcons. Ninety serum samples from 50 aspergillosis-positive falcons and 182 samples from 142 aspergillosis-negative falcons were tested. The sensitivity of the test was only 12 per cent and its specificity was 95 percent. The test was therefore unsatisfactory for detecting galactomannan in the serum samples and cannot be used as a screening test for aspergillosis in falcons.

Bacterial flora of the conjunctiva and nasal cavity in normal and diseased captive bustards.

A survey was carried out to describe the normal aerobic bacterial flora of the conjunctiva and nasal cavity of captive houbara bustards (Chlamydotis undulata), kori bustards (Ardeotis kori), and white-bellied bustards (Eupodotis senegalensis) maintained at the National Avian Research Center, Abu Dhabi, United Arab Emirates. A total of 58 samples were examined from the nasal cavity and 55 samples from the conjunctiva of healthy bustards. There was no bacterial growth in 45% of conjunctival samples. Bacteria isolated from the conjunctiva of healthy birds included Micrococcus spp., Staphylococcus auricularis, Staphylococcus xylosus, Staphylococcus capitis, Staphylococcus warneri, Bacillus spp., and Enterobacter amigenus. Bacteria isolated from the nasal cavity of healthy birds included Bacillus spp., Micrococcus spp., S. auricularis, S. xylosus, Staphylococcus simulans, Staphylococcus saprophyticus, Staphylococcus hyicus, Staphylococcus cohnii, Staphylococcus sciuri, Aerococcus spp., and Providencia rettgeri. These findings were compared with bacterial isolates from bustards with clinical signs of ocular or upper respiratory tract diseases. Mycoplasma spp., Pseudomonas aeruginosa, Pseudomonas stutzeri, Proteus mirabilis, Escherichia coli, Klebsiella spp., Aeromonas hydrophila, and Staphylococcus aureus were the pathogenic bacteria isolated from the conjunctiva of 34.3% bustards with ocular discharges. Mycoplasma spp., P. aeruginosa, Pseudomonas spp., P. mirabilis, E. coli, Klebsiella pneumoniae, and S. aureus were the pathogenic bacteria isolated from the nasal cavity of 74% bustards with upper respiratory tract diseases.

Pseudomonas aeruginosa infections in kori bustards (Ardeotis kori).

Pseudomonas aeruginosa associated upper respiratory tract infections occurred in a flock of 19 juvenile kori bustards. Morbidity was 32% and all birds recovered after parenteral treatment with combinations of enrofloxacin, gentamicin and piperacillin, although gentamicin toxicity was suspected in one bird. A marked haemoresponse occurred 3-10 days after the onset of clinical signs and included leukocytosis, heterophilia, monocytosis and thrombocytosis. Predisposing factors to infection included recent translocation, changes to flock size, extreme temperatures and age.

Intestinal protozoa and associated bacteria in captive houbara bustards (Chlamydotis undulata) in the United Arab Emirates.

A protozoal survey was carried out in 114 captive houbara bustards (Chlamydotis undulata) in the United Arab Emirates. Trichomonas gallinarum, Chilomastix gallinarum, Giardia spp. and Lophomonas spp. were detected from faecal samples of 49 (43%) captive houbara bustards. Culture and identification studies were carried out to assess associated bacteria. The bacteria isolated from birds negative to protozoa included Enterococcus spp., Aerococcus spp., Micrococci spp., Proteus spp., Enterobacter spp., Escherichia coli and Klebsiella spp., while Enterococcus spp., Micrococci kristinae, Aerococcus spp., Staphylococcus sciuri, Staphylococcus aureus, E. coli, Klebsiella spp. and Alcaligenes faecalis were isolated from protozoa positive birds. Proteus spp., Enterobacter spp., E. coli , Klebsiella spp., Aerococcus spp. and Enterococcus spp. are considered part of the normal intestinal bacterial flora of captive bustards and they were also isolated from the food items used to feed the captive bustards. S. sciuri possibly originated from ingested mice; Alcaligenes faecalis and Micrococcus spp. are contaminants from soil or water.

Pharmacokinetics of enrofloxacin after intravenous, intramuscular and oral administration in houbara bustard (Chlamydotis undulata macqueenii).

The in-vitro activity of enrofloxacin against 117 strains of bacteria isolated from bustards was determined. Minimum inhibitory concentrations for 72% of the Proteus spp., E. coli, Salmonella spp. and Klebsiella spp. (n = 61) and for 48% of the Streptococci spp. and Staphylococci spp. (n = 31) were < or = 0.5 microg/mL. The minimum inhibitory concentration (MIC) of 76% of Pseudomonas spp. (n = 25) was < or = 2 microg/mL. Fourteen strains were resistant to concentrations > or = 128 microg/mL. The elimination half-lives (t1/2 elim beta) (mean +/- SEM) of 10 mg/kg enrofloxacin in eight houbara bustards (Chlamydotis undulata) were 6.80 +/- 0.79, 6.39 +/- 1.49 and 5.63 +/- 0.54 h after oral (p.o.), intramuscular (i.m.) and intravenous (i.v.) administration, respectively. Enrofloxacin was rapidly absorbed from the bustard gastro-intestinal tract and maximum plasma concentrations of 1.84 +/- 0.16 microg/mL were achieved after 0.66 +/- 0.05 h. Maximum plasma concentration after i.m. administration of 10 mg/kg was 2.75 +/- 0.11 microg/mL at 1.72 +/- 0.19 h. Maximum plasma concentration after i.m. administration of 15 mg/kg in two birds was 4.86 microg/mL. Bioavailability was 97.3 +/- 13.7% and 62.7 +/- 11.1% after i.m. and oral administration, respectively. Plasma concentrations of enrofloxacin > or = 0.5 microg/mL were maintained for at least 12 h for all routes at 10 mg/kg and for 24 h after i.m. administration at 15 mg/kg. Plasma enrofloxacin concentrations were monitored during the first 3 days of treatment in five houbara bustards and kori bustards (Ardeotis kori) with bacterial infections receiving a single daily i.m. injection of 10 mg/kg for 3 days. The mean plasma enrofloxacin concentrations in the clinical cases at 27 and 51 h (3.69 and 3.86 microg/mL) and at 48 h (0.70 microg/mL) were significantly higher compared with the 3 h and 24 h time intervals from clinically normal birds. The maximum plasma concentration (Cmax)/MIC ratio was ranked i.v. (10/mg/kg) > i.m. (15 mg/kg) > i.m. (10 mg/kg) > oral (10 mg/kg), but it was only higher than 8:1 for i.v. and i.m. administrations of enrofloxacin at 10 mg/kg and 15 mg/kg, respectively, against a low MIC (0.5 microg/mL). A dosage regimen of 10 mg/kg repeated every 12 h, or 15 mg/kg repeated every 24 h, would be expected to give blood concentrations above 0. 5 microg/mL and hence provide therapeutic response in the bustard against a wide range of bacterial infections.

Developmental intestinal aerobic microflora in the kori bustard (Ardeotis kori).

A study was carried out to investigate the normal aerobic bacterial flora of developing kori bustard (Ardeotis kori) chicks, captive bred at the National Avian Research Center, Abu Dhabi, United Arab Emirates. Faecal samples were collected from 14 birds at different ages from the first day of hatching until 99 days old and were cultured for aerobic bacteria. Several bacterial species were isolated from the cultures, they included Escherichia coli, Streptococcus viridians, Enterococcus faecalis, Klebsiella oxytoca, Proteus spp., Enterobacter, spp. and Serratia marcescens. Gram-negative bacilli were isolated from all but one of the faecal samples collected. They were also the predominant bacteria, accounting for between 55.6 and 73.4% of the mean colony count of faecal cultures from all age groups. E. coli was the most frequently isolated bacteria, the frequency and mean colony count increased as the birds grew older. Gram-positive cocci were isolated from between 50 and 100% of the faecal samples from all age groups, and they accounted for between 26.6 and 44.4% of the mean colony count. Results from this study indicated that Gram-negative bacilli and Gram-positive cocci can be isolated frequently from the faeces of developing, clinically normal, captive bred kori bustard chicks.

Oro-pharyngeal protozoa in captive bustards: Clinical and pathological considerations.

An oro-pharyngeal protozoal survey was carried out in captive bustards in the United Arab Emirates. .Endolimax spp., .Entamoeba gallinarum, Acanthamoeba spp., .Naegleria spp. and .Coccidia spp. were the protozoa isolated from the oro-pharynx of clinically normal birds. The protozoa species involved in oro-pharyngeal diseases were .Trichomonas gallinae and .Entamoeba anatis. Most of the protozoa observed in clinical cases were associated with severe secondary bacterial infections possibly due to the suppression of normal oro-pharyngeal bacterial flora which includes .Escherichia coli, Enterobacter spp., .Klebsiella spp. and .Citrobacter spp. In this respect, .Pseudomonas spp., and .Staphylococcus spp., were isolated from individuals affected with oro-pharyngeal diseases. In such cases, inflammatory changes in the oro-pharynx were detected associated with white-yellow caseous nodular lesions, mucous discharge, exfoliation of epithelial cells and the presence of inflammatory cells.

Antimicrobial resistance and minimum inhibitory concentrations of bacteria isolated from bustards in the United Arab Emirates.

The resistance to 11 antimicrobial agents of bacteria isolated from clinical and postmortem cases of five species of bustards maintained in captivity in the United Arab Emirates (UAE) from 1995 to 1997 was determined by disc sensitivity. Of 226 isolates, 169 (74.8%) were gram-negative bacilli, with the majority identified as Escherichia coli (28.8%) and Pseudomonas aeruginosa (19%). The isolates of E. coli showed a high prevalence of resistance to amoxycillin (69%), tetracycline (66.7%), and sulphamethoxazole (43.3%). Moderate resistance to enrofloxacin was observed in E. coli (30%) and P. aeruginosa (19%) isolates. The minimum inhibitory concentrations (MICs) to seven antimicrobial agents were determined for 133 bacterial isolates from bustards during 1996 to 1997. Enrofloxacin (concentration required to inhibit 50% of the isolates [MIC50] < 0.5 microgram/ml) and gentamicin (MIC50 < or = 1.0 microgram/ml) exhibited good activity against both gram-negative bacilli and staphylococci isolated from bustards. Enrofloxacin (MIC50 < or = 1.5 micrograms/ml), gentamicin (MIC50 < or = 2.0 micrograms/ml), and piperacillin (MIC50 < or = 4.0 micrograms/ml) exhibited good activity against P. aeruginosa isolates. Amoxycillin/clavulanic acid showed good activity (concentration required to inhibit 90% of the isolates [MIC90] < or = 2.0 micrograms/ml) against gram-positive cocci and moderate activity (MIC50 < or = 3.0 micrograms/ml) against E. coli, Salmonella spp., and Klebsiella spp. Amoxycillin exhibited good activity (MIC50 < or = 0.5 microgram/ml) against gram-positive organisms and moderate activity (MIC50 < or = 1.0 microgram/ml) against Salmonella spp. These results provide information on the prevalence of resistant bacterial strains and the MICs of organisms derived from bustards in the UAE.