Formalin-fixed and paraffin-embedded tissues of chickens are useful for retrospective studies on pathology of H5N1 Highly Pathogenic Avian Influenza Virus (HPAI) outbreaks in Nigeria

In a retrospective study, histopathology and immunohistochemistry (IHC) were performed on formalin-fixed paraffin embedded (FFPE) archival tissues from chickens obtained during outbreaks of highly pathogenic avian influenza (HPAI) H5N1 that occurred in Nigeria in 2006 and 2007. Ten samples as representative of 10 outbreaks were selected, and following the detection of HPAI viral antigen in different chicken tissues using IHC, RNA was extracted from each sample and molecular analysis was performed using real-time reverse transcription-polymerase chain reaction (rRT-PCR) targeting matrix protein. Seven rRT-PCR positive samples were then subjected to conventional and rRT-PCR assays for the amplification of hemagglutinin (HA) gene. Four of them were further characterized by sequence analysis of a short HA2-part of the H5 gene. Along the 154 nucleotides sequenced, differences at 4 positions were detected in one sample. One of these mutations led to an amino acid exchange at position 544 (Ala>Thr) whereas the others were silent. The study suggests the potential application for retrospective IHC and PCR analysis of FFPE tissues from chickens involved in the AI outbreaks for pathologic studies and providing short fragment sequences which may help in the characterization of viral strains and tracing the outbreaks. This is important as archived poultry tissues can be re-examined for possibility of earlier introduction of the virus.Keywords: Avian influenza; FFPE; H5N1; Nigeria; Immunohistochemistry; real-time RT-PC

Identification of Novel Feline Paramyxoviruses in Guignas (Leopardus guigna) from Chile

The family of paramyxoviruses has received growing attention as several new species have been identified recently, notably two different clusters in domestic cats, designated as feline morbillivirus (FeMV) and feline paramyxovirus (FPaV). Their phylogenetic origin and whether wild felids also harbor these viruses are currently unknown. Kidney samples from 35 guignas (Leopardus guigna), a wild felid from Chile, were investigated for paramyxoviruses using consensus-RT-PCR. In addition, thirteen serum samples of guignas were screened for the presence of FeMV-specific antibodies by an immunofluorescence assay (IFA). Viral RNA was detected in 31% of the kidney samples. Phylogenetic analyses revealed two well-supported clusters, related to isolates from domestic cats, rodents and bats. No significant histopathology changes were recorded in infected guignas. Serology identified two samples which were positive for FeMV-specific antibodies. Our study highlights the diversity of paramyxovirus infections in felids with special emphasis on guignas from Chile

Enhanced antiviral function of magnesium chloride-modified Heparin on a broad spectrum of viruses

Previous studies reported on the broad-spectrum antiviral function of heparin. Here we investigated the antiviral function of magnesium-modified heparin and found that modified heparin displayed a significantly enhanced antiviral function against human adenovirus (HAdV) in immortalized and primary cells. Nuclear magnetic resonance analyses revealed a conformational change of heparin when complexed with magnesium. To broadly explore this discovery, we tested the antiviral function of modified heparin against herpes simplex virus type 1 (HSV-1) and found that the replication of HSV-1 was even further decreased compared to aciclovir. Moreover, we investigated the antiviral effect against the new severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) and measured a 55-fold decreased viral load in the supernatant of infected cells associated with a 38-fold decrease in virus growth. The advantage of our modified heparin is an increased antiviral effect compared to regular heparin

Interlaboratory comparison of six real-time PCR assays for detection of bovine leukemia virus proviral DNA

Quantitative real-time PCR (qPCR) is increasingly being used for the detection of bovine leukemia virus (BLV) proviral DNA. Nevertheless, quality control for the validation and standardization of such tests is currently lacking. Therefore, the present study was initiated by three Office International des Epizooties (OIE) reference laboratories and three collaborating laboratories to measure the interlaboratory variability of six already developed and available BLV qPCR assays. For that purpose, an international panel of 58 DNA samples reflecting the dynamic range of the majority of the assays was distributed to six testing centers. Based on qualitative results, the overall agreement among all six laboratories was moderate. However, significant variability in the measurement of the BLV proviral DNA copy number was observed among different laboratories. Quantitative PCR assays, even when performed by experienced staff, can yield large variability in BLV proviral DNA copy numbers without harmonization. Further standardization of different factors (i.e., utilization of unified protocols and unique calibrators) should increase interlaboratory agreement.Fil: Jaworski, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Pluta, A.. National Veterinary Research Institute; PoloniaFil: Rola Luszczak, M.. National Veterinary Research Institute; Polonia. Animal and Plant Health Agency; Reino UnidoFil: McGowan, S.L.. Animal and Plant Health Agency; Reino UnidoFil: Finnegan, C.. Animal and Plant Health Agency; Reino UnidoFil: Heenemann, K.. University of Leipzig; AlemaniaFil: Carignano, Hugo Adrián. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Alvarez, Irene. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Murakami, K.. Iwate University; JapónFil: Willems, L.. Université de Liège; BélgicaFil: Vahlenkamp, T.W.. University of Leipzig; AlemaniaFil: Trono, Karina Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Choudhury, B.. Animal and Plant Health Agency; Reino UnidoFil: Kuzmak, J.. National Veterinary Research Institute; Poloni