Experimental infection of normal and immunosuppressed pigs with Pseudomonas pseudomallei

A single dose of 5 x 10(8) bacilli of Pseudomonas pseudomallei by intratracheal injection resulted in acute (21 cases) or chronic (19 cases) melioidosis in 40 of 48 pigs. Fifteen (10 acute and 5 chronic) had been immunosuppressed by cyclophosphamide before inoculation. The major clinical signs were initial fever, marked neutrophilia and, in the acute cases, respiratory distress. There were no signs of the nasal and ocular discharge, paresis or diarrhoea seen in acute cases in south-east Asia. The cyclophosphamide treatment caused a significant decrease in the neutrophil count by 7 d after inoculation in all 15 immunosuppressed pigs, and all were culture positive at necropsy. Eight of the 33 non-treated pigs were culture negative at necropsy. Pigs overcoming the initial phase of infection had more abscess-like nodules that were bacteriologically sterile at necropsy than the pigs with acute cases of melioidosis. P. pseudomallei was isolated predominantly from the spleen, lungs and the injection site. Although only one strain was used in this study, it is likely that Australian strains of P. pseudomallei are not as virulent as the south-east Asian isolates.     

Tracking the long-term decline and recovery of an isolated population

Effects of small population size and reduced genetic variation on the viability of wild animal populations remain controversial. During a 35-year study of a remnant population of greater prairie chickens, population size decreased from 2000 individuals in 1962 to fewer than 50 by 1994. Concurrently, both fitness, as measured by fertility and hatching rates of eggs, and genetic diversity declined significantly. Conservation measures initiated in 1992 with translocations of birds from large, genetically diverse populations restored egg viability. Thus, sufficient genetic resources appear to be critical for maintaining populations of greater prairie chickens.     

Morbidity and mortality associated with a new mycoplasma species from captive American alligators (Alligator mississippiensis).

Nine of 74 American alligators (Alligator mississippiensis) from a captive Florida herd of 3-4-m-long, 200-350-kg, adult males greater than 30 yr of age died within a 10-day period during 1995. Nonspecific clinical signs included anorexia, lethargy, muscle weakness, paraparesis, bilateral white ocular discharge, and various degrees of periocular, facial, cervical, and limb edema. Pneumonia, pericarditis, and arthritis were found on postmortem evaluation of the spontaneously dead and euthanatized alligators. Rapidly growing mycoplasmas were identified by culture, and mycoplasma nucleotide sequences were identified by polymerase chain reaction testing of fresh lung and synovial fluid from an affected alligator. Culture of banked frozen lung from necropsy specimens and fresh lung and fresh synovial fluid from newly affected alligators confirmed the presence of a new mycoplasma species in seven of eight individuals. Oxytetracycline was administered, but related deaths continued for 6 mo until only 14 of the initial alligators remained. An enzyme-linked immunosorbent assay to detect antibody was developed, and the organism was transmitted experimentally to naive juvenile alligators, although the source of the organism, Mycoplasma sp. (ATCC 700619), has not been identified. The alligator isolate is a novel species in the mycoplasma family because its nucleotide sequence does not match those of over 75 characterized mycoplasma species. Such factors as population density, animal age, and mycoplasmal virulence likely contributed to the course of disease.     

Long‐term Effects of Pyrethrin and Cyfluthrin,a Type II Synthetic Pyrethroid,Insecticide Applications on Bull Reproductive Parameters

The objectives of this study were to determine effects of cyfluthrin and pyrethrin spray products, used in combination with cyfluthrin topical and ear tag applications, on bull reproductive parameters over 18 weeks. Angus or Angus x Simmental bulls were randomly assigned to one of three treatment groups: (i) no exposure to pyrethrins/cyfluthrin (CONT; n = 10), (ii) cyfluthrin ear tag and topical applications (ET; n = 10), or (iii) cyfluthrin ear tag, topical, premise spray and pyrethrin fog spray applications (ET+S; n = 8). Bull body weight was measured every 3 week, and body condition score and scrotal circumference were recorded on weeks 0, 9 and 18. Semen and serum were collected every 3 weeks for sperm evaluation and testosterone measurement, respectively. There was a treatment × week interaction (p < 0.01) for sperm with primary defects; bulls in CONT group had a greater (p = 0.01) percentage of sperm with primary defects than bulls treated with insecticides at week 18. Overall and progressive sperm motility, normal sperm morphology, secondary sperm defects and serum testosterone concentrations changed (p < 0.01) over time in all bulls; however, treatment did not affect (p ≥ 0.13) any of these parameters. There were also no treatment effects (p ≥ 0.08) on bull body weight, body condition score or scrotal circumference. The use of pyrethrin‐ and cyfluthrin‐based insecticides, regardless of application, did not negatively affect reproductive parameters in beef bulls when administered over 18 weeks.     

Cranial edema associated with a protein-losing nephropathy in a golden-mantled flying fox (Pteropus pumilus).

An adult golden-mantled flying fox (Pteropus pumilus) was diagnosed with nephrotic syndrome on the basis of the findings of proteinuria, hypoalbuminemia, hypercholesterolemia, and cranial edema. Membranoproliferative glomerulitis and interstitial nephritis were confirmed antemortem by renal biopsy. The bat had received seven injections of oxytocin in the period immediately prior to presentation. The possible role of oxytocin in the development of the nephropathy is discussed. Supportive care and treatment with a single plasma transfusion, furosemide, and prednisone led to a gradual but complete resolution of the nephrotic syndrome in this animal.     

Penetrating keratoplasty for treatment of corneal protrusion in a great horned owl (Bubo virginianus)

A young adult great horned owl (Bubo virginianus) was examined following presumed trauma. The owl had soft tissue injury to its left wing as well as corneal protrusion, lens subluxation, and iridodialysis of the right eye. The bird's eye was treated surgically with a large, rectangular penetrating keratoplasty. Following escape from housing, the bird was found with partial wound dehiscence and iris prolapse 12 days post operation. Surgical repair was performed and healing progressed for 14 days, at which time the transplant dehisced and the globe was exenterated. The patient rehabilitated well until escaping from its cage again 4 weeks later, at which time it sustained an open comminuted humeral fracture and was euthanized.     

The avian neurologic examination and ancillary neurodiagnostic techniques: a review update.

The purpose of this article is to guide the avian clinician in the assessment of neurologic function in birds. Physical and neurologic examinations that evaluate cranial nerves, postural reactions, and spinal reflexes identify neurologic dysfunction and the corresponding anatomic location of the lesion. Ancillary diagnostic tests, such as cerebrospinal fluid analysis, diagnostic imaging, muscle and nerve histology, and electrodiagnostics, are tools to confirm and clarify conclusions from the neurologic examination and to identify the cause of disease. Once the disease location and pathologic process have been identified, appropriate treatment and prognosis may be provided.     

Local Control of Microdomain Orientation in Diblock Copolymer Thin Films with Electric Fields

Local control of the domain orientation in diblock copolymer thin films can be obtained by the application of electric fields on micrometer-length scales. Thin films of an asymmetric polystyrene-polymethylmethacrylate diblock copolymer, with cylindrical polymethylmethacrylate microdomains, were spin-coated onto substrates previously patterned with planar electrodes. The substrates, 100-nanometer-thick silicon nitride membranes, allow direct observation of the electrodes and the copolymer domain structure by transmission electron microscopy. The cylinders aligned parallel to the electric field lines for fields exceeding 30 kilovolts per centimeter, after annealing at 250°C in an inert atmosphere for 24 hours. This technique could find application in nanostructure fabrication.