Pharmacokinetics of marbofloxacin in blue and gold macaws (Ara ararauna)

OBJECTIVE: To determine the pharmacokinetics of marbofloxacin after single IV and orally administered doses in blue and gold macaws. ANIMALS: 10 healthy blue and gold macaws. PROCEDURES: In a crossover study, marbofloxacin (2.5 mg/kg) was administered orally (via crop gavage) to 5 birds and IV to 5 birds. Blood samples were obtained at 0, 0.5, 1, 3, 6, 12, 24, 48, 72, and 96 hours after marbofloxacin administration. After a 4-week washout period, the study was repeated, with the first 5 birds receiving the dose IV and the second 5 birds receiving the dose orally. Serum marbofloxacin concentrations were quantitated by use of a validated liquid chromatography-mass spectrometry assay. RESULTS: After oral administration, mean +/- SD area under the curve was 7.94 +/- 2.08 microg.h/mL, maximum plasma concentration was 1.08 +/- 0.316 microg/mL, and bioavailability was 90.0 +/- 31%. After IV administration of marbofloxacin, the apparent volume of distribution was 1.3 +/- 0.32 L/kg, plasma clearance was 0.29 +/- 0.078 L/h/kg, area under the curve was 9.41 +/- 2.84 microg.h/mL, and the harmonic mean terminal half-life was 4.3 hours. CONCLUSIONS AND CLINICAL RELEVANCE: Single IV and orally administered doses of marbofloxacin were well tolerated by blue and gold macaws. The orally administered dose was well absorbed. Administration of marbofloxacin at a dosage of 2.5 mg/kg, PO, every 24 hours may be appropriate to control bacterial infections susceptible to marbofloxacin in this species.     

Depletion, degradation, and recovery potential of estuaries and coastal seas

Estuarine and coastal transformation is as old as civilization yet has dramatically accelerated over the past 150 to 300 years. Reconstructed time lines, causes, and consequences of change in 12 once diverse and productive estuaries and coastal seas worldwide show similar patterns: Human impacts have depleted >90% of formerly important species, destroyed >65% of seagrass and wetland habitat, degraded water quality, and accelerated species invasions. Twentieth-century conservation efforts achieved partial recovery of upper trophic levels but have so far failed to restore former ecosystem structure and function. Our results provide detailed historical baselines and quantitative targets for ecosystem-based management and marine conservation.     

Heterogeneous Nature of a ‘new’ Pathotype of Melampsora Rust on Salix Revealed by AFLP

An outbreak of rust on Salix × mollissima (S. triandra × S. viminalis) Q83, an important biomass willow, was first observed at several locations in the UK in 1992. Rust collections obtained from Q83 in 1992 at Long Ashton (south west England), Markington (Northern England) and Loughgall (Northern Ireland), were tested for pathogenicity and examined using amplified fragment length polymorphism (AFLP). All collections showed the same pathogenicity patterns on the eight willow differentials and were assigned to f.sp. larici-epitea typica of Melampsora epitea. A total of 304 AFLP markers was scored for 54 rust isolates, 20 from Long Ashton, 20 from Markington and 14 from Loughgall. Cluster analysis placed the isolates into three distinct groups according to the collection sites. Within each site, Markington isolates were least variable, Nei & Li's similarity coefficients averaging 0.996. Average similarities within isolates from Long Ashton and Loughgall were 0.899 and 0.883, respectively. Average per-locus diversity within site (H_j), calculated using Shannon information index, was 0.014 in Markington, 0.24 in Long Ashton and 0.23 in Loughgall population. Most diversity (69.1%) was partitioned between populations. An analysis of molecular variance (AMOVA) attributed 85.8% of variance to between populations and 14.2% to the individuals within populations. The results suggest that, in 1992, this previously unknown pathotype was not spread from a common source but from separate sources. The AFLP analysis and early records on the host range of M. epitea indicate that the rust virulent to S. × mollissima may have existed in nature before 1992.