Avian diseases最新文献

Salmonella enterica subspecies enterica serovar Gallinarum biovar Pullorum (S. Pullorum) is a pathogenic bacterium that causes Pullorum disease (PD). PD is an acute systemic disease that affects young chickens, causing white diarrhea and high mortality. Although many sanitary programs have been carried out to eradicate S. Pullorum, PD outbreaks have been reported in different types of birds (layers, broilers, breeders) worldwide. This study aimed to evaluate the evolution and genetic characteristics of S. Pullorum isolated from PD in Brazil. Phylogenetic analysis of S. Pullorum genomes sequenced in this study and available genomic databases demonstrated that all isolates from Brazil are from sequence type 92 (ST92) and cluster into two lineages (III and IV). ColpVC, IncFIC(FII), and IncFII(S) were plasmid replicons frequently found in the Brazilian lineages. Two resistance genes (aac(6')-Iaa, conferring resistance to aminoglycoside, disinfecting agents, and antiseptics (mdf(A)) and tetracycline (mdf(A)) were detected frequently. Altogether, these results are important to understand the circulation of S. Pullorum and, consequently, to develop strategies to reduce losses due to PD.

Acute myocardial injury (AMI) induced by lipopolysaccharide (LPS) can cause cardiovascular dysfunction and lead to death in poultry. Traditional antibiotic therapy has been found to have many limitations and negative effects. Asiatic acid (AA) is a naturally occurring pentacyclic triterpenoid that is extracted from Centella asiatica and has anti-inflammatory, antioxidant, and anticancer pharmacological properties. Previously, we studied the effect of AA on LPS-induced liver and kidney injury; however, the impact of AA on LPS-induced AMI remained unclear. Sixty 1-day-old broilers were randomly divided into control group, LPS group, LPS + AA 15 mg/kg group, LPS + AA 30 mg/kg group, LPS + AA 60 mg/kg group, and control + AA 60 mg/kg group. The histopathology of cardiac tissues was detected by hematoxylin and eosin (H&E) staining. The mRNA and protein expressions related to mitochondrial dynamics and mitophagy were detected by quantitative real-time PCR, western blot, immunofluorescence, and immunohistochemistry. Disorganized myocardial cells and fractured myocardial fibers were found in the LPS group, and obvious red-blood-cell filling can be seen in the gaps between the myocardial fibers in the low-dose AA group. Nevertheless, the medium and high dose of AA obviously attenuated these changes. Our results showed that AA significantly restored the mRNA and protein expressions related to mitochondrial dynamic through further promoting mitophagy. This study revealed the effect of AA on LPS-induced AMI in broilers. Mechanically, AA regulated mitochondrial dynamic homeostasis and further promoted mitophagy. These novel findings indicate that AA may be a potential drug for LPS-induced AMI in broilers.

The aim of this study was to develop a multiplex PCR assay capable of rapidly differentiating two major Avipoxvirus (APV) species, Fowlpox virus (FWPV) and Pigeonpox virus (PGPV), which cause disease in bird species. Despite the importance of a rapid differentiation assay, no such assay exists that can differentiate the APV species without sequencing. To achieve this, species-specific target DNA fragments were selected from the fpv122 gene of FWPV and the HM89_gp120 gene of PGPV, which are unique to each genome. Nine samples collected from unvaccinated chickens, pigeons, and a turkey with typical pox lesions were genetically identified as FWPV and PGPV. The designed primers and target DNA fragments were validated using in silico analyses with the nucleotide Basic Local Alignment Search Tool. The multiplex PCR assay consisted of species-specific primers and previously described PanAPV primers (genus-specific) and was able to differentiate FWPV and PGPV, consistent with the phylogenetic outputs. This study represents the first successful differentiation of FWPV and PGPV genomes using a conventional multiplex PCR test. This assay has the potential to facilitate the rapid diagnosis and control of APV infections.

High mortality in great cormorants (Phalacrocorax carbo) was registered on the Alakol Lake in eastern Kazakhstan in 2021 when about 20% of juveniles died. High-throughput sequencing revealed the presence of a putative novel cormorant adenovirus significantly divergent from known aviadenoviruses. We suggest that this cormorant adenovirus can be considered an emerging threat to the health and conservation of this species.

Highly pathogenic avian influenza (HPAI) has resulted in catastrophic economic losses globally in poultry. This case report describes the diagnostic detection and pathology of HPAI H5N1 in 5-day-old commercial ducklings, which is an atypical age for detection of natural infection of HPAI in poultry. The pathology observed at 5 days of age was also compared to lesions observed in ducklings from the same flock evaluated at 10 days of age before depopulation. The California Animal Health and Food Safety (CAHFS) Laboratory, Tulare, received ten 5-day-old Pekin duckling (Anas platyrhynchos domesticus) carcasses for diagnostic evaluation due to mortality that started increasing at 3 days of age. The most common gross findings included bilateral pulmonary edema with congestion and enlarged, mottled livers and spleens. Microscopically, cerebral neuronophagia, pancreatic necrosis, and interstitial pneumonia with pulmonary edema were observed in the 5-day-old ducklings. Oropharyngeal and cloacal swabs were positive for avian influenza virus (AIV) by real-time reverse transcriptase PCR. The AIV was typed as HPAI, EA/AM 2.3.4.4b H5N1 goose/Guangdong clade lineage by the National Veterinary Services Laboratory. Ducks at the affected premises were depopulated 4 days after the 5-day-old ducklings were submitted to the CAHFS lab, at which time additional tissue samples were collected for comparison to 10-day-old ducklings on the same premises. Differences in microscopic lesions and AIV tissue distribution were observed between the 5-day and 10-day tissues collected. Notably, microscopic lesions were more severe in the brain and pancreas at 10 days of age. Findings in 10-day-old ducklings included cerebral lymphoplasmacytic perivascular cuffing, gliosis, neuronal degeneration, and pancreatic necrosis. AIV antigen distribution and intensity was greatest in the cerebral tissue of the brains at 10 days and in the lungs at 5 days of age. To the authors' knowledge, published studies are limited on AIV natural infection in domestic ducks less than 9 days of age.

We isolated a high pathogenicity avian influenza (HPAI) virus from a common pochard (Aythya ferina) that was being attacked by a bird of prey in South Korea in December 2020. Genetic analyses indicated that the isolate was closely related to the clade 2.3.4.4b H5N8 HPAI viruses found in South Korea and Japan during the winter season of 2020-2021. The histopathological examination revealed multifocal necrotizing inflammation in the liver, kidney, and spleen. Viral antigens were detected in the liver, kidney, spleen, trachea, intestine, and pancreas, indicating the HPAI virus caused a systemic infection. The presence of immunoreactivity for the viral antigen was observed in the cells involved in multifocal necrotic inflammation. Notably, epitheliotropic-positive patterns were identified in the epithelial cells of the trachea, mucosal epithelium of the intestine, and ductular epithelium of the pancreas. These findings provide direct evidence supporting the possibility of HPAI transmission from infected waterfowl to predators.