Antimicrobial peptide Epinecidin-1 promotes complete skin regeneration of methicillin-resistant Staphylococcus aureus -infected burn wounds in a swine model

Newcastle disease (ND) is a devastating worldwide disease of poultry characterized by increased respiration, circulatory disturbances, hemorrhagic enteritis, and nervous signs. Sequence analysis shows several amino acid residue substitutions at neutralizing epitopes on the F and HN proteins of recent Shaanxi strains. Both Cross protection and cross serum neutralization tests revealed that the traditional vaccine strains were unable to provide full protection for the flocks. To better understand the epidemiology of Newcastle disease outbreak, a portion of the F gene and the full-length HN gene were amplified from Shaanxi isolates by reverse transcription-polymerase chain reaction (RT-PCR) and then conducted sequence and phylogenetic analyzes. In pathogenicity analysis, both high intra-cerebral pathogenicity index (ICPI) and mean death time (MDT) tests of chicken embryo were carried out. Furthermore, a cross-protection experiment in which specific-pathogen-free chickens vaccinated with a LaSota vaccine strain were challenged by the recent Shaanxi strain was also performed. Nine Newcastle disease (ND) virus (NDV) isolates which were recovered from ND outbreaks in chicken flocks in China were genotypically and pathotypically characterized. Amino acid sequence analysis revealed that all the recent Shaanxi-isolated NDVs have 112R-R-Q-K-R-F117 for the C-terminus of the F2 protein and exhibit high ICPI and MDT of chicken embryos, suggesting that they were all classified as velogenic type of NDVs. Phylogenetic analysis of these isolates showed that they belong to subgenotype VIId that have been implicated in the recent outbreaks in northwestern China. The percentage of amino acid sequence identity of F protein between recent Shaanxi stains and five vaccine strains was in the range of 81.9 %–88.1 %, while the percentage of amino acid sequence identity of HN protein between recent Shaanxi strains and vaccine strains was in the range of 87.4 %–91.2 %. Furthermore, a number of amino acid residue substitutions at neutralizing epitopes on the F and HN proteins of these isolates were observed, which may lead to the change of antibody recognition and neutralization capacity. A cross-protection experiment indicated that specific-pathogen-free chickens vaccinated with a LaSota vaccine strain was not capable of providing full protection for the flocks that were challenged by the recent Shaanxi strain. Taken together, our findings reveal that recent Shannxi NDVstrains exhibit antigenic variations that could be responsible for recent outbreaks of NDVs in northwestern China.

Pigeons (Columba livia) infected with pigeon circovirus (PiCV) have been reported worldwide. The present study diagnosed PiCV infection in tissue samples of disqualified racing pigeons in Taiwan, using molecular and microscopy diagnostics. Among the 164 dead pigeons examined, 96.95% (159/164) tested positive for PiCV. Severe histopathological lesions, with characteristic inclusions, were observed in various organs of the PiCV-infected pigeons. Multiglobular basophilic intranuclear and intracytoplasmic inclusion bodies were found in the bursa of Fabricius and non-lymphoid tissues. The present study identified, for the first time, the presence of inclusion bodies in the thyroid gland, oesophagus, gizzard, and in the third eyelid of circovirus-infected pigeons. The presence of inclusion bodies in the third eyelid and mucosa of the gizzard was confirmed by transmission electron microscopy. A high detection rate of PiCV and some severe lesions evident in disqualified racing pigeons, as well as PiCV sequences in this study were highly similar with those detected in European countries suggesting an epidemiological association possibly due to imported pigeons.

Ting CH, et al. J Vet Sci. 2020 Dec;22:e1. https://doi.org/10.4142/jvs.2021.22.e1