The role of oxidative stress in Brachiaria decumbens toxicity in sheep

In an attempt to elucidate potential time-dependent oxidative stress mechanisms associated with Brachiaria decumbens toxicity in sheep, selected blood malondialdehyde (MD), as peroxidation tissue function biomarker and tissue morphology, were assessed. Six young adult Wiltshire cross bred ram were acclimatized for 3 weeks, where ivermectin injection and liver and kidney function tests were done. Blood samples were collected during the pre-treatment, namely on 3rd, 5th, 7th, 9th, and 11th days of continuous feeding of Brachiaria. Meanwhile, clinical signs were monitored and sheep were euthanised on the 7th, 9th, and 11th day, where a post-mortem was performed and relevant tissues were sampled. Results revealed that plasma thiobarbituric acid reactive substances (TBARS), serum (bilirubin total and conjugated, AST, GGT, urea, and creatinine) were significantly (p<0.05) increased, whereas total antioxidant potential was decreased (p<0.05) in a time dependant manner. Continuous B. decumbens feeding induced a time dependent appearance of jaundice, photosensitization, and subcutaneous oedema. Unique intracytoplasmic accumulation of Schmorl's positive greenish lipofuscin granules were observed primarily within the centrilobular hepatocytes and Kupffer cells. This may serve as a histochemical oxidative biomarker in the liver, kidney, brain, and skin. Taken together, this study shows that oxidative stress plays a major role in B. decumbens toxicity

Molecular and pathological identification of feline coronavirus type I

The coronavirus in cats has been described as feline infectious peritonitis (FIPV) and feline enteric coronavirus (FECV). FIPV is highly fatal and caused immune-mediated pyogranulomatous disease, whereas FECV causes mild enteric infection. In this study, we described the isolation and molecular characterization of naturally occurring feline coronavirus from domestic cat in Malaysia. Additionally, the resultant pathological conditions observed in the infected cat were reported. Ascitic fluid sample was collected from 3-year-old domestic cat clinically suspected of effusive (wet form) FIP and subjected to virus isolation in Felis catus whole fetus cell cultures (Fcwf-4). The result of virus isolation was confirmed using one step reverse transcription polymerase chain reaction (RT-PCR). To gain insight on the genetic variant of FCoV, the S-gene sequence was amplified using type 1 specific primers. Virus isolation showed cytopathic effect (CPE) characterized by giant cells, ballooning and cells detachment. Ultrastructural findings showed virus particles attached to plasma membrane and later invaginated from the cell membrane. Virus-like particles were also observed in the vacuoles, likely as a result of spillage of mature virus-like particles into the cytoplasmic matrix. Histopathological examination of kidney, spleen and intestine organ samples revealed coagulative necrosis with infiltration of neutrophils and mononuclear cells. In conclusion, this study reports the first isolation of feline coronavirus in Malaysian cats and importantly the isolated virus was confirmed to be type I using S-gene amplification.Key words: Feline coronavirus, Fcwf-4, RT-PCR, effusive FIP, ultrastructure, histopathology

Molecular and pathological identification of feline coronavirus type I

The coronavirus in cats has been described as feline infectious peritonitis (FIPV) and feline enteric coronavirus (FECV). FIPV is highly fatal and caused immune-mediated pyogranulomatous disease, whereas FECV causes mild enteric infection. In this study, we described the isolation and molecular characterization of naturally occurring feline coronavirus from domestic cat in Malaysia. Additionally, the resultant pathological conditions observed in the infected cat were reported. Ascitic fluid sample was collected from 3-year-old domestic cat clinically suspected of effusive (wet form) FIP and subjected to virus isolation in Felis catus whole fetus cell cultures (Fcwf-4). The result of virus isolation was confirmed using one step reverse transcription polymerase chain reaction (RT-PCR). To gain insight on the genetic variant of FCoV, the S-gene sequence was amplified using type 1 specific primers.Virus isolation showed cytopathic effect (CPE) characterized by giant cells, ballooning and cells detachment. Ultrastructural findings showed virus particles attached to plasma membrane and later invaginated from the cell membrane. Virus-like particles were also observed in the vacuoles, likely as a result of spillage of mature virus-like particles into the cytoplasmic matrix. Histopathological examination of kidney, spleen and intestine organ samples revealed coagulative necrosis with infiltration of neutrophils and mononuclear cells. In conclusion, this study reports the first isolation of feline coronavirus in Malaysian cats and importantly the isolated virus was confirmed to be type I using S-gene amplification