Erysipelothrix amsterdamensis sp. nov., associated with mortalities among endangered seabirds.

Infectious diseases threaten endangered species, particularly in small isolated populations. Seabird populations on the remote Amsterdam Island in the Indian Ocean have been in decline for the past three decades, with avian cholera caused by Pasteurella multocida proposed as the primary driver. However, Erysipelothrix species have also been sporadically detected from albatrosses on Amsterdam Island and may be contributing to some of the observed mortality. In this study, we genomically characterized 16 Erysipelothrix species isolates obtained from three Indian yellow-nosed albatross (Thalassarche carteri) chick carcasses in 2019. Histological analyses suggest that they died of bacterial septicaemia. Two isolates were sequenced using both Illumina short-read and MinION long-read approaches, which - following hybrid assembly - resulted in closed circular genomes. Mapping of Illumina reads from the remaining isolates to one of these new reference genomes revealed that all 16 isolates were closely related, with a maximum of 13 nucleotide differences distinguishing any pair of isolates. The nucleotide diversity of isolates obtained from the same or different carcasses was similar, suggesting all three chicks were likely infected from a common source. These genomes were compared with a global collection of genomes from Erysipelothrix rhusiopathiae and other species from the same genus. The isolates from albatrosses were phylogenetically distinct, sharing a most recent common ancestor with E. rhusiopathiae. Based on phylogenomic analysis and standard thresholds for average nucleotide identity and digital DNA-DNA hybridization, these isolates represent a novel Erysipelothrix species, for which we propose the name Erysipelothrix amsterdamensis sp. nov. The type strain is A18Y020dT (=CIP 112216T=DSM 115297T). The implications of this bacterium for albatross conservation will require further study.

WHOLE GENOME SEQUENCING OF AN AVIPOXVIRUS ASSOCIATED WITH INFECTIONS IN A GROUP OF AVIARY-HOUSED SNOW BUNTINGS (PLECTROPHENAX NIVALIS).

Avipoxvirus infections have been reported in both free-ranging and domestic birds worldwide. Fowlpox and canarypox viruses belong to the genus Avipoxvirus among the virus family Poxviridae. They cause cutaneous lesions with proliferative growths on the unfeathered parts of the skin and/or diphtheritic lesions generally associated with necrosis in the upper respiratory and digestive tracts. In this study, a poxvirus has been identified in wild-caught snow buntings (Plectrophenax nivalis) housed in an outdoor aviary in the region of Rimouski, Quebec. During the falls and winters of 2015 and 2016, eight snow buntings affected by this infection were examined. Macroscopic and microscopic lesions observed were characteristic of an avipoxvirus infection. Electron microscopy imaging of an ultrathin section of the histopathological lesions of two birds confirmed the presence of the poxvirus. Afterward, the presence of the poxvirus was confirmed in three birds by a specific polymerase chain reaction assay that amplified a segment of the gene encoding the fowlpox virus 4b core protein. A 576-nucleotide amplicon was obtained from one of them and sequenced. The analyses revealed a 99% homology to other previously described avipoxviruses. Using high-throughput sequencing, almost the entire viral genome of this avipoxvirus was revealed and found to possess a 359,853-nucleotide sequence in length. Bioinformatic analyses revealed that the virus was genetically related to canarypox virus. To our knowledge, this is the first confirmed case and full description of a poxviral infection in this species. This episode suggests a high susceptibility of this northern species of passerine to avipoxviruses circulating in southeastern Canada during the summer months. Even if the source of the viral infections remains undetermined, transmission by local biological vectors is suspected. Management of poxviral infections in snow buntings housed outdoors in southeastern Canada could rely on the control of biting insects.

Lymphoproliferative Disease Virus in Wild Turkeys (Meleagris gallopavo) from Manitoba and Quebec, Canada.

This study describes the first recognized clinical case of lymphoproliferative disease virus (LPDV) in Canada and extends the range of LPDV in Canada through its detection in Manitoba and Quebec. We assessed the prevalence of LPDV in eastern wild turkeys (Meleagris gallopavo silvestris) with the use of whole, clotted blood from live birds in Manitoba (n = 65) and tissue samples collected postmortem in Quebec (n = 4). We tested for LPDV proviral DNA through PCR amplification and sequencing of a portion of the gag (p31) gene. Samples were also tested for reticuloendotheliosis virus (REV) by PCR. Twenty-four birds (34.8%) were positive for LPDV, including all diagnostic cases. One bird (1.4%) from Quebec had gross and microscopic lesions consistent with LPDV. Two turkeys (2.9%) were REV positive, one (1.4%) of which was co-infected with LPDV. Phylogenetic analysis of LPDV strains from Quebec and Manitoba grouped with previously sequenced samples from Ontario and publicly available sequences from a North American lineage. This study contributes valuable information toward ongoing surveillance and monitoring of LPDV in North America.

Virus de la enfermedad linfoproliferativa en pavos silvestres (Meleagris gallopavo) de Manitoba y Quebec, en Canadá. Este estudio describe el primer caso clínico reconocido del virus de la enfermedad linfoproliferativa (LPDV) en Canadá y extiende el rango de detección de este virus a través de su detección en Manitoba y Quebec. Se evaluó la prevalencia del virus de la enfermedad linfoproliferativa en pavos silvestres (Meleagris gallopavo silvestris) de la parte oriental, mediante el uso de sangre coagulada de aves vivas en Manitoba (n = 65) y de muestras de tejidos recolectadas postmortem en Quebec (n = 4). Se analizó el ADN proviral del virus de la enfermedad linfoproliferativa del pavo a través de la amplificación por PCR y la secuenciación de una parte del gene gag (p31). Las muestras también se analizaron para detectar el virus de la reticuloendoteliosis (REV) mediante PCR. Veinticuatro aves (34.8%) resultaron positivas para la presencia del virus de la enfermedad linfoproliferativa, incluyendo todos los casos diagnósticos. Un ave (1.4%) de Quebec tenía lesiones macroscópicas y microscópicas compatibles con este virus. Dos pavos (2.9%) fueron positivos a la presencia del virus de la reticuloendoteliosis, uno (1.4%) de los cuales se co-infectó con el virus de la enfermedad linfoproliferativa. El análisis filogenético de cepas del virus de la enfermedad linfoproliferativa de Quebec y Manitoba agrupó a estos virus con muestras previamente secuenciadas de Ontario y secuencias disponibles públicamente de un linaje de América del Norte. Este estudio aporta información valiosa para la vigilancia y el monitoreo continuos del virus de la enfermedad linfoproliferativa en América del Norte.