Phylogenetic Analysis and Characterization of a Sporadic Isolate of Equine Influenza A H3N8 from an Unvaccinated Horse in 2015.

Equine influenza, caused by the H3N8 subtype, is a highly contagious respiratory disease affecting equid populations worldwide and has led to serious epidemics and transboundary pandemics. This study describes the phylogenetic characterization and replication kinetics of recently-isolated H3N8 virus from a nasal swab obtained from a sporadic case of natural infection in an unvaccinated horse from Montana, USA. The nasal swab tested positive for equine influenza by Real-Time Quantitative Reverse Transcription Polymerase Chain Reaction (RT-PCR). Further, the whole genome sequencing of the virus confirmed that it was the H3N8 subtype and was designated as A/equine/Montana/9564-1/2015 (H3N8). A BLASTn search revealed that the polymerase basic protein 1 (PB1), polymerase acidic (PA), hemagglutinin (HA), nucleoprotein (NP), and matrix (M) segments of this H3N8 isolate shared the highest percentage identity to A/equine/Tennessee/29A/2014 (H3N8) and the polymerase basic protein 2 (PB2), neuraminidase (NA), and non-structural protein (NS) segments to A/equine/Malaysia/M201/2015 (H3N8). Phylogenetic characterization of individual gene segments, using currently available H3N8 viral genomes, of both equine and canine origin, further established that A/equine/Montana/9564-1/2015 belonged to the Florida Clade 1 viruses. Interestingly, replication kinetics of this H3N8 virus, using airway derived primary cells from multiple species, such as equine, swine, bovine, and human lung epithelial cells, demonstrated appreciable titers, when compared to Madin-Darby canine kidney epithelial cells. These findings indicate the broad host spectrum of this virus isolate and suggest the potential for cross-species transmissibility.

Ring test evaluation of the detection of influenza A virus in swine oral fluids by real-time reverse-transcription polymerase chain reaction and virus isolation.

The probability of detecting influenza A virus (IAV) in oral fluid (OF) specimens was calculated for each of 13 assays based on real-time reverse-transcription polymerase chain reaction (rRT-PCR) and 7 assays based on virus isolation (VI). The OF specimens were inoculated with H1N1 or H3N2 IAV and serially diluted 10-fold (10(-1) to 10(-8)). Eight participating laboratories received 180 randomized OF samples (10 replicates × 8 dilutions × 2 IAV subtypes plus 20 IAV-negative samples) and performed the rRT-PCR and VI procedure(s) of their choice. Analysis of the results with a mixed-effect logistic-regression model identified dilution and assay as variables significant (P < 0.0001) for IAV detection in OF by rRT-PCR or VI. Virus subtype was not significant for IAV detection by either rRT-PCR (P = 0.457) or VI (P = 0.101). For rRT-PCR the cycle threshold (Ct) values increased consistently with dilution but varied widely. Therefore, it was not possible to predict VI success on the basis of Ct values. The success of VI was inversely related to the dilution of the sample; the assay was generally unsuccessful at lower virus concentrations. Successful swine health monitoring and disease surveillance require assays with consistent performance, but significant differences in reproducibility were observed among the assays evaluated.

La probabilité de détecter le virus de l'influenza A (VIA) dans des échantillons de fluide oral (FO) a été calculée pour chacune des 13 épreuves basées sur une réaction d'amplification en chaine en temps réel utilisant la polymérase réverse (rRT-PCR) et 7 épreuves basées sur l'isolement viral (IV). Les échantillons de FO ont été inoculés avec du VIA H1N1 ou H3N2 et dilués en série par facteur de 10 (10−1 à 10−8). Huit laboratoires participants ont reçu 180 échantillons randomisés de FO (10 réplicats × 8 dilutions × 2 sous-types de VIA plus 20 échantillons témoins négatifs sans VIA) et ont réalisé la méthode de rRT-PCR et d'IV de leur choix. L'analyse des résultats à l'aide d'un modèle de régression logistique pour les effets mélangés a identifié la dilution et l'épreuve comme étant des variables significatives (P < 0,0001) pour la détection de VIA dans du FO par rRT-PCR ou IV. Le sous-type de virus n'était pas significatif pour la détection de VIA soit par rRT-PCR (P = 0,457) ou par IV (P = 0,101). Pour les épreuves rRT-PCR les valeurs seuils de cycle (Ct) augmentaient de manière constante avec la dilution mais variaient énormément. Ainsi, il n'était pas possible de prédire le succès de l'IV sur la base des valeurs de Ct. Le succès de l'IV était inversement relié à la dilution de l'échantillon; l'épreuve était généralement négative aux faibles concentrations de virus. Pour avoir du succès dans la surveillance des maladies et de la santé des porcs il est nécessaire d'avoir des épreuves avec des performances constantes, mais des différences significatives dans la reproductibilité ont été observées parmi les épreuves évaluées.(Traduit par Docteur Serge Messier).

Activation of Snake in a serine protease cascade that defines the dorsoventral axis is atypical and pipe-independent in Drosophila embryos.

During Drosophila embryogenesis, establishment of ventral and lateral cell fates requires spatial regulation of an extracellular serine protease cascade composed of Nudel, Gastrulation Defective (GD), Snake, and Easter. Pipe, a sulfotransferase expressed ventrally during oogenesis, sulfates secreted targets that somehow confer positive spatial input to this cascade. Nudel and GD activation are pipe-independent, while Easter activation requires pipe. The effect of pipe on Snake activation has been unknown. Here we show that Snake activation is cascade-dependent but pipe-independent. These findings support a conclusion that Snake's activation of Easter is the first spatially regulated step in the dorsoventral protease cascade.

Bovine viral diarrhea virus multiorgan infection in two white-tailed deer in southeastern South Dakota.

The susceptibility of wild ruminants, especially cervids, to bovine viral diarrhea virus (BVDV) has remained an enigma. Two white-tailed deer (Odocoileus virginianus) were submitted to the Animal Disease Research and Diagnostic Laboratory (ADRDL) in the fall of 2003 by the South Dakota Game Fish and Parks for chronic wasting disease (CWD) testing. Both animals were CWD negative. The animals were necropsied and histopathology, viral antigen detection, and virus isolation were performed. A noncytopathic (NCP) BVDV was isolated from the lungs and several other tissues of both animals. Formalin-fixed ear notches from both animals were positive for BVDV antigen by immunohistochemistry. The BVDV isolates were typed with the use of polymerase chain reaction in 5' untranslated region (UTR) and one isolate was typed a Type 2a and the other a Type 1b. Future field surveys to determine the incidence of BVDV along with experimental studies to determine if white-tailed deer fawns can be persistently infected with BVDV are needed.

Airway obstruction in children aged less than 5 years: the prehospital experience.

BACKGROUND: Treatment of choking in children has been well studied, but few data are available on the various causes of the choking episodes in the pediatric population. OBJECTIVES: To assess frequency and to stratify etiologies of children less than 5 years of age who had a 911 advanced life support (ALS) ambulance response for airway obstruction. METHODS: A prehospital database was searched and information was collected defining type of obstruction, age of the child, parents' action, paramedic treatment, and incident outcome. RESULTS: There were 182 patients with airway obstruction under 5 years of age, of whom 99 (55%) were less than 1 year old. Liquid obstructions (i.e., formula, juices) were most common in the youngest children, whereas solid food and nonfood solid obstructions were most prevalent in children over 1 year old. One hundred seven (59%) of these obstructions resolved before paramedic arrival (69% of liquid obstructions, 72% of food, and 36% of nonfood solid objects). Interventions used by parents included bulb suction (3%), finger sweeps (6%), Heimlich maneuver (3%), and back blows (12%). Paramedics used ALS skills in only three cases. After paramedic evaluation, 47% of parents refused transport against medical advice (AMA). CONCLUSIONS: Although most episodes of pediatric airway obstruction will have been resolved by the time of paramedic arrival, age-specific and item-specific treatment skills need to be reinforced with parents and prehospital providers.

Characterization of emerging European-like porcine reproductive and respiratory syndrome virus isolates in the United States.

European-like field isolates of porcine reproductive and respiratory syndrome virus (PRRSV) have recently emerged in North America. The full-length genomic sequence of an index isolate characterized in 1999, strain EuroPRRSV, served as the reference strain for further studies of the evolution and epidemiology of European-like isolates (type 1) in the United States. Strain EuroPRRSV shared 90.1 to 100% amino acid identity with the prototype European strain, Lelystad, within the structural and nonstructural open reading frames (ORFs) and 95.3% overall nucleotide identity. The 5' untranslated region and two nonstructural regions within ORF 1 were closely examined due to significant divergence from strain Lelystad. A 51-bp deletion in a region within ORF 1a, coding for nonstructural protein 2 (NSP2), was observed. Sequence analysis of the structural ORFs 2 to 7 of additional European-like isolates indicated that these isolates share 93% nucleotide identity with one another and 95 to 96% identity with the Lelystad strain but only 70% identity with the North American reference strain VR-2332. Phylogenetic analysis with published PRRSV ORF 3, 5, and 7 nucleotide sequences indicated that these newly emerging isolates form a clade with the Lelystad and United Kingdom PRRSV isolates. Detailed analysis of four of these isolates with a panel of 60 monoclonal antibodies directed against the structural proteins confirmed a recognition pattern that was more consistent with strain Lelystad than with other North American isolates.

Out-of-hospital pediatric intubation by paramedics: the San Diego experience.

To evaluate pediatric endotracheal intubations by our paramedics, we performed a retrospective review of a prehospital computer database, quality assurance reviews, and prehospital run sheets for all patients under 15 years of age who had an endotracheal tube (ETT) placed. During the 4.5-year study period, 324 pediatric patients had intubation attempts by field paramedics, of which 264 (82%) were successful and three were reported esophageal and unrecognized by the paramedic. Two of these esophageal placements were noted on arrival at the hospital, and one upon turn-over of patient care to a nurse of an aeromedical service. All three intubations were deemed esophageal with direct laryngoscopy, and the patients had been in cardiopulmonary arrest status prior to the intubation. Of the 264 patients who had ETT placed, 99% were endotracheal, while only 1% were unrecognized esophageal. We conclude that pediatric endotracheal intubation by out-of-hospital paramedics in an established EMS system has a low occurrence of unrecognized esophageal placements.