Comparative studies of the use of some injectable anaesthetic agents in birds

The effect of three injectable drugs and a combination of two of them was compared in birds. The agents were ketamine hydrochloride, xylazine hydrochloride and the steroid mixture alphaxalone-alphadolone. Ketamine and xylazine were used in combination. One hundred and fifty-four species, all maintained by major zoos in the United Kingdom, were involved in the study. The results indicate that the drugs used produced more widely differing effects in the range of species studied than have previously been reported.     

Seasonal effects on the aerobic bacterial and fungal conjunctival flora of normal thoroughbred brood mares in Florida

Objective To evaluate seasonal effects on the presence or absence of fungal and aerobic bacterial flora of the conjunctival fornix of normal Florida Thoroughbred horses. Sample population Both eyes of 100 horses. Procedure Horses with normal anterior segment ophthalmic examinations from three farms in north central Florida were included. Each animal had the ventral conjunctival fornix of each eye swabbed with sterile culturettes. Samples were taken in October, January, April, and July (1999–2000). Aerobic and fungal cultures were plated. Bacterial cultures were reviewed at 24 and 48 h. Fungal cultures were reviewed weekly for 4 weeks. Logistic regression analysis with season as a factor and age of the horse as a covariate was performed. Statistical significance was set at P < 0.01. Results Horses ranged from 3 to 24 years of age, with a median age of 9 years. Twenty‐four genera of bacteria and 35 genera of fungi were recovered. Corynebacterium sp., Staphylococcus sp., Bacillus sp. and Moraxella sp. were the bacteria most frequently isolated. Mold species, dematiaceous mold species, Chrysosporium sp., Cladosporium sp., and Aspergillus sp. were the most frequently recovered fungi. Season did not have a significant effect on the presence of microorganisms isolated for individual horses adjusted for age. Younger horses had an increased incidence of gram‐negative rods and fungal isolates. The number of bacteria and fungi isolated are not uniform across seasons. Conclusion There were no significant differences between the number or type of organisms cultured during the sampling seasons in normal Florida horses. A large range of normal bacterial and fungal flora were isolated from these horses. The number of bacteria and fungi isolated are not uniform across seasons. The likelihood of detecting an organism depends on the horses’ age.     

Bacteriocin-Like Substances from Tomato Race 3 Strains of Xanthomonas campestris pv. vesicatoria

ABSTRACT Tomato race 3 (T3) strains of Xanthomonas campestris pv. vesicatoria are antagonistic in vitro to tomato race 1 (T1) strains of the bacterium. All T1 strains and 11 strains of other X. campestris pathovars tested were inhibited by T3 strains. Sensitivity of tomato race 2 (T2) strains was variable. No strains from other bacterial genera tested were inhibited. Cell-free filtrates from T3 strains were inhibitory to sensitive strains. The inhibitory activity of these filtrates was lost after treatment at temperatures above 80 degrees C and with selected protease enzymes. However, treatment with trypsin or DNase had no effect on their activity. Seven cosmid clones from a genomic library of a T3 strain were selected for their ability to consistently inhibit a sensitive indicator strain in plate assays. Southern hybridization analysis placed these into three bacteriocin (BCN)-producing groups designated BCN-A, BCN-B, and BCN-C. The BCN-like groups could be differentiated by variations in inhibitory spectra and levels of activity in plate assays. Mutations that inactivated expression of each BCN group individually in a wild-type T3 strain had inhibitory activity confirming that multiple BCNs are present in the T3 strain. T3 strains were inhibitory to a sensitive indicator strain in tomato leaf tissue, but this effect was observed only when T3 strains were applied in advance of the sensitive strain. BCN-A was the major BCN-like substance involved in the suppression of the sensitive indicator strain in tomato leaf tissues.     

Ultrastructural and cytochemical aspects of silicon-mediated rice blast resistance

ABSTRACT Although exogenous application of silicon (Si) confers efficient control of rice blast, the probable hypothesis underlying this phenomenon has been confined to that of a mechanical barrier resulting from Si polymerization in planta. However, in this study, we provide the first cytological evidence that Si-mediated resistance to Magnaporthe grisea in rice correlates with specific leaf cell reaction that interfered with the development of the fungus. Accumulation of an amorphous material that stained densely with toluidine blue and reacted positively to osmium tetroxide was a typical feature of cell reaction to infection by M. grisea in samples from Si+ plants. As a result, the extent of fungal colonization was markedly reduced in samples from Si+ plants. In samples from Si- plants, M. grisea grew actively and colonized all leaf tissues. Cytochemi-cal labeling of chitin revealed no difference in the pattern of chitin localization over fungal cell walls of either Si+ or Si- plants at 96 h after inoculation, indicating limited production of chitinases by the rice plant as a mechanism of defense response. On the other hand, the occurrence of empty fungal hyphae, surrounded or trapped in amorphous material, in samples from Si+ plants suggests that phenolic-like compounds or phytoalexins played a primary role in rice defense response against infection by M. grisea. This finding brings new insights into the complex role played by Si in the nature of rice blast resistance.     

Effects of an S6 strain of Mycoplasma gallisepticum challenge at onset of lay on digestive and reproductive tract characteristics in commercial layers

Mycoplasma gallisepticum (MG), a reproductive/respiratory pathogen in poultry, has been implicated in suboptimum egg production and decreased hatchability. Commercial layer hens raised in a controlled environment were inoculated with the S6 strain of MG at 20 wk of age. The S6 inoculation had no effect on bird weight, egg production, digestive tract weight and length, or histopathologic lesion scores, although significant differences were noted in the lengths and weights of various portions of the reproductive tract. This study shows that S6MG inoculation does not detrimentally affect layer hen performance when in the absence of environmental stressors customary to a caged layer facility.     

Assessment of the accuracy of computed tomography for measurement of normal equine pituitary glands

OBJECTIVE: To describe the anatomic features of the pituitary gland region in horses via computed tomography (CT) and determine the accuracy of CT for estimating normal equine pituitary gland dimensions. ANIMALS: 25 adult horses with no clinical signs of pituitary disease. PROCEDURE: Transverse CT images and gross transverse tissue sections were compared in 2 horses. Contrast-enhanced CT of the pituitary gland region was performed postmortem in 23 horses with 4 slice thickness and interval settings (10-mm contiguous or overlapping slices and 4-mm contiguous or overlapping slices). Gross and CT estimates of pituitary gland dimensions were compared via ANOVA. Accuracy of CT estimates was calculated with gross pituitary gland measurements as the known value. RESULTS: Pituitary glands were located between the temporomandibular joints and had contrast enhancement. Mean gross dimensions were length, 2.11 cm; width, 2.16 cm; height, 0.98 cm; and volume, 2.66 cm3. Gross measurements and CT estimates of pituitary gland length from 10-mm contiguous and overlapping slices did not differ. Gross measurements and CT estimates of pituitary gland width from 4-mm contiguous and overlapping slices did not differ. Estimates of height and volume from all CT techniques differed from gross measurements. Accuracies for CT estimates were length, 88 to 99%; width, 81 to 92%; height, 58 to 71%; and volume, 43 to 55%. CONCLUSIONS AND CLINICAL RELEVANCE: Accuracy of estimates of pituitary gland dimension in horses varied with CT scanning technique; via CT estimates of length and width of glands were more accurate than estimates of height or volume.     

Isoflurane to prolong medetomidine/ ketamine anaesthesia in six adult female chimpanzees (Pan troglodytes)

Six adult female chimpanzees (Pan troglodytes) were anaesthetised for the placement of intrauterine contraceptive devices, microchips for identification, routine blood sampling, and physical measurements. Anaesthesia was induced with medetomidine in combination with ketamine administered by intramuscular injection with a projectile syringe. Induction was smooth and rapid, but five of the animals were insufficiently relaxed for orotracheal intubation. The plane of anaesthesia was deepened by administering isoflurane delivered in oxygen and nitrous oxide, and general anaesthesia was maintained for up to 74 minutes. The action of medetomidine was reversed at the end of each procedure with atipamezole, and the animals recovered smoothly and uneventfully.     

The accessory lung lobe in thoracic disease: a case series and anatomical review

Diseases of the accessory lung lobe (AccLL) are often overlooked in dogs and cats, perhaps because of its recessed location. Diseases of this lobe also can mimic diseases of the diaphragm or structures comprising the caudal mediastinum. Normal anatomy of the AccLL and the diagnostic tools used today will be reviewed to help differentiate disease of adjacent organs. Four cases will also be described to illustrate disease presentation and radiographic findings affecting this lobe.     

Poor systemic antibody response after vaccination of commercial broiler breeders with Mycoplasma gallisepticum vaccine ts-11 not associated with susceptibility to challenge

A live attenuated Mycoplasma gallisepticum vaccine, ts-11, has been used for control of M gallisepticum in several countries. The rapid serum agglutination test is usually used as an indicator of flock response to vaccination; however, in some flocks, the detected response may be weak or absent. We investigated whether the low level, or lack, of systemic antibodies in ts-11-vaccinated flocks is correlated with susceptibility to infection after challenge with a virulent M. gallisepticum strain. Birds from 2 separate ts-11-vaccinated commercial flocks with no, or weak, rapid serum agglutination responses (at 11 or 14 wk postvaccination) were randomly selected and subjected to aerosol challenge with either M gallisepticum strain Ap3AS or sterile mycoplasma broth. A group of nonvaccinated specific-pathogen-free chickens at similar age were also exposed to aerosolization with M. gallisepticum strain Ap3AS and used as positive controls. Postmortem examination of the birds, performed 2 wk after challenge, revealed no significant difference in microscopic tracheal lesions or mucosal thicknesses between the ts-11-vaccinated field birds irrespective of their aerosolization treatment. However, both microscopic tracheal lesions and tracheal mucosal thicknesses of nonvaccinated challenged birds were significantly greater than those of ts-11 vaccinates. Hence, broiler breeders vaccinated in the field showed significant protection against virulent M. gallisepticum challenge even when no serum antibody was detected by rapid serum agglutination test. These results reveal that seroconversion detected by rapid serum agglutination test after ts-11 vaccination is not a reliable predictor of protection against M. gallisepticum infection. The possible significance of local antibody response and cell-mediated immunity against M. gallisepticum infection is discussed.