Experimental Infection of Peromyscus Species Rodents with Sin Nombre Virus.

We demonstrate that 6 distinct Peromyscus rodent species are permissive to experimental infection with Sin Nombre orthohantavirus (SNV). Viral RNA and SNV antibodies were detected in members of all 6 species. P. leucopus mice demonstrated markedly higher viral and antibody titers than P. maniculatus mice, the established primary hosts for SNV.

Jamestown Canyon and snowshoe hare virus seroprevalence in New Brunswick.

Background: Jamestown Canyon virus (JCV) and snowshoe hare virus (SSHV) are wide-ranging mosquito-borne arboviruses in the California serogroup viruses (CSGV) that are known to circulate in New Brunswick. Despite potential for debilitating central nervous system manifestations, the prevalence of human exposure to these viruses in New Brunswick is unknown. The goal of this study was to quantify rates of human exposure in New Brunswick to these neglected arboviruses. Methods: A retrospective, anonymized provincial serosurvey was performed using a stratified random sample of residual sera submitted between May 2015 and August 2016. To determine the seroprevalence of JCV and SSHV, competitive enzyme-linked immunosorbent assay-positive samples were confirmed positive using plaque-reduction neutralization testing (PRNT). Results: A total of 452 serum samples were screened. The seroprevalence of antibodies against CSGV was estimated to be 31.6% (95% CI 27.4% to 36.1%) with 143 positive samples. PRNT results indicated that most single virus exposures were due to JCV (38 of 143; 26.6%) rather than SSHV (3 of 143; 2.1%). The species of CSGV, to which the remaining 102 seropositive people were exposed, could not be precisely determined. Conclusions: The prevalence of human exposure to CSGV is high but comparable to rates observed in other Atlantic Canadian jurisdictions. Studies such as this provide important baseline epidemiological data regarding the risk of exposure to these neglected arboviruses. SSHV and JCV should be considered in the differential diagnosis for undiagnosed febrile and neuroinvasive illness during mosquito season, particularly when testing for common aetiologies is negative or inconclusive.

Historique : Le virus de Jamestown Canyon (VJC) et le virus du lièvre d'Amérique (VLA) sont des arbovirus à grande portée transmis par des moustiques des virus du sérogroupe Californie (VSGC) qui circulent au Nouveau-Brunswick (NB). Malgré le risque de manifestations débilitantes du système nerveux central, on ne connaît pas la prévalence d'exposition humaine à ces virus au NB. La présente étude visait à quantifier le taux d'exposition humaine à ces arbovirus négligés au NB. Méthodologie : Les chercheurs ont réalisé une enquête sérologique rétrospective provinciale anonymisée au moyen d'un échantillon randomisé stratifié de sérum résiduel soumis entre mai 2015 et août 2016 au dépistage systématique. Ils ont stratifié le processus de sélection selon l'âge, le sexe et la zone de santé régionale afin de garantir un échantillonnage proportionné. Pour déterminer la séroprévalence du VJC et du VLA, ils ont confirmé la positivité des résultats d'échantillons positifs au test ELISA au moyen de tests de séroneutralisation par réduction des plaques (TSRP). Résultats : Au total, 452 échantillons de sérum ont fait l'objet d'un dépistage. Au NB, la séroprévalence des anticorps anti-VSGC était évaluée à 31,6 % (IC à 95 %, 27,4 % à 36,1 %), pour 143 échantillons positifs. Selon les résultats du TSRP, la plupart des expositions à un seul virus étaient causées par le VJC (38 cas sur 143, 26,6 %) plutôt qu'au VLA (trois cas sur 143, 2,1 %). Les espèces de VSGC, auxquelles les 102 autres personnes séropositives ont été exposées, n'ont pas pu être établies avec précision. Conclusions : La prévalence d'exposition humaine au VSGC est élevée, mais comparable aux taux observés dans d'autres régions des provinces de l'Atlantique. Des études comme celle-ci fournissent des données épidémiologiques de référence importantes à l'égard du risque d'exposition humaine à ces arbovirus négligés. Il faut tenir compte du VLA et du VJC dans le diagnostic différentiel de maladie fébrile et neuro-invasive pendant la saison des moustiques, notamment lorsque les tests pour dépister d'autres étiologies courantes sont négatifs ou non concluants.

Bird Species Involved in West Nile Virus Epidemiological Cycle in Southern Québec.

Despite many studies on West Nile Virus (WNV) in the US, including the reservoir role of bird species and the summer shifts of the Culex mosquito, feeding from birds to mammals, there have been few equivalent studies in the neighboring regions of Canada where WNV is endemic. Here, a priority list of bird species likely involved in WNV transmission in the greater Montréal area is constructed by combining three sources of data: (i) from WNV surveillance in wild birds (2002-2015); (ii) blood meal analysis of Culex pipiens-restuans (CPR), the primary enzootic vectors of WNV in the region, collected from surveillance in 2008 and 2014; (iii) literature review on the sero-prevalence/host competence of resident birds. Each of these data sources yielded 18, 23 and 53 species, and overall, 67 different bird species were identified as potential WNV amplifiers/reservoirs. Of those identified from CPR blood meals, Common starlings, American robins, Song sparrows and House sparrows ranked the highest and blood meal analysis demonstrated a seasonal shift in feed preference from birds to mammals by CPR. Our study indicates that there are broad similarities in the ecology of WNV between our region and the northeastern US, although the relative importance of bird species varies somewhat between regions.

Vector Competence of Some Mosquito Species From Canada For Zika Virus.

The recent introduction of Zika virus (ZIKV) into the Americas and the occurrence of birth defects associated with infection during pregnancy have created a concern about the spread of this virus into more northern countries in the Americas. Therefore, we examined several species of mosquitoes found in southern Manitoba, Canada, for their susceptibility to infection and their ability to transmit ZIKV. Aedes cinereus, Ae. euedes, Ae. fitchii, Ae. sticticus, Ae. vexans, Coquillettidia perturbans, Culex restuans, and Cx. tarsalis were captured in the vicinity of Winnipeg, Manitoba; brought to the laboratory; and allowed to feed on a ZIKV-sheep blood suspension to determine oral susceptibility. In addition, some of the nonfed individuals were inoculated intrathoracically to examine for the presence of a salivary gland barrier. Despite ingesting blood containing 105.4 plaque-forming units/ml, infection rates were very low, and infected individuals were only detected for Ae. vexans. Transmission was observed for Ae. vexans, Cq. perturbans, and Cx. restuans that had been inoculated with ZIKV, although rates were low. Based on the extremely low vector competence found in this study and the lack of a preferential feeding on humans, it is unlikely than any of the mosquito species tested in this study would be involved in any large-scale transmission of ZIKV in Canada.

The first case of locally acquired tick-borne Babesia microti infection in Canada.

A child with a complicated medical history that included asplenia acquired an infection with Babesia microti in the summer of 2013 and had not travelled outside of Manitoba. Although the clinical findings were subtle, astute laboratory work helped to reach a preliminary identification of Babesia species, while reference laboratory testing confirmed the diagnosis. Blacklegged ticks (Ixodes scapularis) are known to transmit Borrelia burgdorferi and Anaplasma phagocytophilum in the province; however, the present case represents the first known instance of tick-borne B microti, both in Manitoba and in Canada. The expanding territory of the blacklegged tick increases the relevance of this emerging infection. Clinicians, laboratory medical practitioners and public health officials should be aware of B microti as a potential locally acquired infection in Canada.

Un enfant ayant des antécédents médicaux complexes, qui incluaient une asplénie, a contracté une infection à Babesia microti pendant l'été 2013, sans avoir quitté le Manitoba. Même si les résultats cliniques étaient discrets, un travail de laboratoire astucieux a contribué à l'identification préliminaire d'une espèce de Babesia. Le test du laboratoire de référence a confirmé le diagnostic. On sait que les tiques occidentales à pattes noires (Ixodes scapularis) transmettent le Borrelia burgdorferi et l'Anaplasma phagocytophilum dans la province. Le présent cas est toutefois la première occurrence connue de B microti à tique, tant au Manitoba qu'au Canada. L'expansion du territoire de la tique occidentale à pattes noires renforce la pertinence de cette infection émergente. Les cliniciens, les praticiens de laboratoires médicaux et les directeurs de la santé publique devraient savoir que le B microti peut être transmis localement au Canada.

Identification of group I introns within the SSU rDNA gene in species of Ceratocystiopsis and related taxa.

During a recent phylogenetic study, group I introns were noted that interrupt the nuclear small subunit ribosomal RNA (SSU rDNA) gene in species of Ceratocystiopsis. Group I introns were found to be inserted at the following rDNA positions: S943, S989, and S1199. The introns have been characterized and phylogenetic analysis of the host gene and the corresponding intron data suggest that for S943 vertical transfer and frequent loss appear to be the most parsimonious explanation for the distribution of nuclear SSU rDNA introns among species of Ceratocystiopsis. The SSU rDNA data do suggest that a recent proposal of segregating the genus Ophiostoma sensu lato into Ophiostoma sensu stricto, Grosmannia, and Ceratocystiopsis has some merit but may need further amendments, as the SSU rDNA suggests that Ophiostoma s. str. may now represent a paraphyletic grouping.

Development of three additional Culex species-specific polymerase chain reaction primers and their application in West Nile virus surveillance in Canada.

In 2002, more than 17,000 mosquito pools collected in Canada (Quebec, Ontario, and Manitoba) were tested at the National Microbiology Laboratory in Winnipeg, Manitoba, for infection with West Nile virus (WNV). Using real-time reverse-transcriptase polymerase chain reaction (RT-PCR), 558 mosquito pools (86% Culex species and 14% other species) had evidence of infection with WNV. Only 30% of the Culex specimens, however, were identified to the species level. In this study, Culex species-specific PCR primers were designed to identify individual mosquitoes and mixed pools of Culex mosquitoes to species. In addition, pools of non-Culex mosquitoes that tested positive for WNV were also screened for Culex DNA to determine the frequency of cross-contamination among mosquitoes of different species. All DNA extracts from 121 Culex and 51 non-Culex pools, previously positive for WNV, were screened, and Culex DNA was detected in approximately 6% of non-Culex pools. This study demonstrates that contamination among mosquito species can occur and emphasizes that precautions should be taken to minimize this potentially confounding effect.

Molecular evolution of the mtDNA encoded rps3 gene among filamentous ascomycetes fungi with an emphasis on the Ophiostomatoid fungi.

The mitochondrial ribosomal protein S3 (rps3) gene within the fungi is extremely diverse in location and organization, some versions of this gene have been incorporated into a group I intron, others appear to have gained large insertions, microsatellite expansions, or have been invaded by homing endonucleases. Among the ascomycetes fungi the group I intron encoded version of rps3 appears to have a rather complex evolutionary history including first the acquisition of rps3 by a group I intron (mL2449), the loss of the mL2499 intron and the establishment of rps3 as a free-standing gene, and the eventual loss of the intron derived version of rps3.

Phylogeny and jaw ontogeny of beloniform fishes.

To investigate jaw evolution in beloniform fishes, we reconstructed the phylogeny of 54 species using fragments of two nuclear (RAG2 and Tmo-4C4) and two mitochondrial (cytochrome b and 16S rRNA) genes. Our total molecular evidence topology refutes the monophyly of needlefishes (Belonidae) and halfbeaks (Hemiramphidae), but supports the monophyly of flyingfishes (Exocoetidae) and sauries (Scomberesocidae). Flyingfishes are nested within halfbeaks, and sauries are nested within needlefishes. Optimization of jaw characters on the tree reveals a diverse array of evolutionary changes in ontogeny. During their development, needlefishes pass through a "halfbeak" stage that closely resembles the adult condition in the hemiramphid halfbeaks. The reconstruction of jaw transitions falsifies the hypothesis that halfbeaks are paedomorphic derivatives of needlefishes. Instead, halfbeaks make up a basal paraphyletic grade within beloniforms, and the needlefish jaw morphology is relatively derived. The parallel between needlefish ontogeny and beloniform phylogeny is discussed, and clades amenable to future morphological analysis are proposed.