Time dependent effects of graded levels of Fusarium toxin contaminated maize in diets for female piglets

The study was conducted to evaluate the effect of graded levels of the Fusarium toxins zearalenone (ZEA) and deoxynivalenol (DON) in diets for female piglets during 29 days of treatment on the development of performance, organ weights, clinical serum characteristics, differential blood counts and vulva morphology. For this purpose, 120 female weaned piglets with an initial mean bodyweight of 8.9±1.6 kg, were assigned to 5 feeding groups (n=24). The piglets of groups 1 to 5 received diets containing 0, 1.25, 2.5, 5 and 10% naturally contaminated maize instead of control maize, resulting in 0.01, 0.05, 0.08, 0.17 and 0.29 mg ZEA/kg, and 0.03, 0.59, 1.27, 2.01 and 4.52 mg DON/kg feed, respectively. After 1, 3, 8, 15, 22 and 29 days, 20 piglets (four piglets from each group) were slaughtered. Animals of group 5 consumed at least 20% less feed than animals of the other feeding groups. Body weight gain was significantly reduced in group 5 in the last week compared to group 2 and 3. Relative visceral organ weights were not affected by the treatments, but they mostly showed some minimal time dependent alterations. Uterus weights tended to be decreased in group 5 on day 15 of the experiment. Though not significant, signs of hyperoestrogenism such as swelling of the vulva became more pronounced with increasing time of exposure. Histopathological examination of organ specimens did not reveal any toxin related lesions. Total leukocytes, differential blood count and stimulation index of peripheral blood mononuclear cells were not affected by the diet, however, the proportion of lymphocytes increased while neutrophils decreased during the experiment independent of treatment. Clinical chemical serum characteristics were not affected by the treatments, however, they were somewhat affected by time. In conclusion, the dose related effects of ZEA and DON on performance and signs of hyperoestrogenism seemed to be dependent on exposure time.

Establishment of a model of Streptococcus iniae meningoencephalitis in Nile tilapia (Oreochromis niloticus)

Streptococcus iniae is an invasive pathogen causing meningitis and other lesions in various fish species. Furthermore, S. iniae is an emerging zoonotic agent that causes cellulitis in man. The aims of this study were to establish an intraperitoneal infection model for S. iniae in Nile tilapia (Oreochromis niloticus) and to develop a new histopathological scoring system to reflect the degree and extent of inflammation as well as the presence of necrosis in the brain and eye. Intraperitoneal administration of 10(6) colony-forming units (CFU) led to 80% mortality and numerous fish developing clinical signs of central nervous system dysfunction. Microscopical examination of four regions of the brain (olfactory bulb, cerebellum, cerebrum and optical lobe) and the eye revealed the presence of lymphohistiocytic leptomeningitis, meningoencephalitis and endophthalmitis. Lesions were dominated by macrophages that often contained intracellular bacteria. Necrosis was recorded in some cases. Bacteriological screening revealed that multiple organs, including brain and eye, were infected with S. iniae and S. iniae colonized the scales and gills in high number. S. iniae was detected in tank water during the first week post infection, suggesting that infected tilapia might shed up to 3 × 10(7) CFU of S. iniae within 24 h. A multiplex polymerase chain reaction allowed confirmation of the challenge strain by detection of the virulence factors simA, scpI, cpsD, pgi, pgm and sagA.

Multiple cutaneous ganglioneuromas in a dog

A 3-year-old male Labrador retriever dog was presented with multifocal small cutaneous nodules, distributed mainly over the thoracic wall, the flank and the scrotum. The dog was otherwise in good health and had no significant past medical history. Radio- and sonographic examination revealed no evidence of internal tumours, including endocrine tumours. Histological examination of two excised samples revealed round, non-ulcerated nodules in the superficial corium, characterized by two different neoplastic cell components and mild inflammation. The first tumour cell population showed histomorphological characteristics of mature ganglion cells; the second featured small, spindle-shaped tumour cells with scant cytoplasm. Both neoplastic cell components expressed vimentin, neurofilament protein, pan-neuronal neurofilament, amyloid-precursor protein and chromogranin A. In addition, the spindle-shaped tumour cells were positive for 2', 3'-cyclicnucleotide 3'-phosphodiesterase. The findings had many histological and immunohistochemical features in common with primary cutaneous ganglioneuromas in humans, enabling the canine tumours to be also classified as multiple cutaneous ganglioneuromas.