RESUMO
The envelope (E) protein of the avian coronavirus infectious bronchitis virus (IBV) is a small-membrane protein present in two forms during infection: a monomer and a pentameric ion channel. Each form has an independent role during replication; the monomer disrupts the secretory pathway, and the pentamer facilitates virion production. The presence of a T16A or A26F mutation within E exclusively generates the pentameric or monomeric form, respectively. We generated two recombinant IBVs (rIBVs) based on the apathogenic molecular clone Beau-R, containing either a T16A or A26F mutation, denoted as BeauR-T16A and BeauR-A26F. The replication and genetic stability of the rIBVs were assessed in several different cell types, including primary and continuous cells, ex vivo tracheal organ cultures (TOCs) and in ovo. Different replication profiles were observed between cell cultures of different origins. BeauR-A26F replicated to a lower level than Beau-R in Vero cells and in ovo but not in DF1, primary chicken kidney (CK) cells or TOCs. Genetic stability and cytopathic effects were found to differ depending on the cell system. The effect of the T16A and A26F mutations appear to be cell-type dependent, which, therefore, highlights the importance of cell type in the investigation of the IBV E protein.
Assuntos
Infecções por Coronavirus , Gammacoronavirus , Vírus da Bronquite Infecciosa , Animais , Galinhas , Chlorocebus aethiops , Infecções por Coronavirus/veterinária , Vírus da Bronquite Infecciosa/genética , Mutação , Células VeroRESUMO
The Gammacoronavirus infectious bronchitis virus (IBV) is a highly contagious economically important respiratory pathogen of domestic fowl. Reverse genetics allows for the molecular study of pathogenic determinants to enable rational vaccine design. The recombinant IBV (rIBV) Beau-R, a molecular clone of the apathogenic Beaudette strain, has previously been investigated as a vaccine platform. To determine tissues in which Beau-R could effectively deliver antigenic genes, an in vivo study in chickens, the natural host, was used to compare the pattern of viral dissemination of Beau-R to the pathogenic strain M41-CK. Replication of Beau-R was found to be restricted to soft tissue within the beak, whereas M41-CK was detected in beak tissue, trachea and eyelid up to seven days post infection. In vitro assays further identified that, unlike M41-CK, Beau-R could not replicate at 41 °C, the core body temperature of a chicken, but is able to replicate a 37 °C, a temperature relatable to the very upper respiratory tract. Using a panel of rIBVs with defined mutations in the structural and accessory genes, viral replication at permissive and non-permissive temperatures was investigated, identifying that the Beau-R replicase gene was a determinant of temperature sensitivity and that sub-genomic mRNA synthesis had been affected. The identification of temperature sensitive allelic lesions within the Beau-R replicase gene opens up the possibility of using this method of attenuation in other IBV strains for future vaccine development as well as a method to investigate the functions of the IBV replicase proteins.
Assuntos
Infecções por Coronavirus/prevenção & controle , Vírus da Bronquite Infecciosa/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinação/veterinária , Vacinas Virais/imunologia , Animais , Linhagem Celular , Embrião de Galinha , Galinhas , Aves Domésticas/virologia , Doenças das Aves Domésticas/virologia , RNA Viral/genética , Temperatura , Vacinas Atenuadas/imunologia , Replicação Viral/genética , Replicação Viral/fisiologiaRESUMO
Introduction: The effectiveness of formaldehyde as a fumigant in laboratories, for equipment, and for containment barrier decontamination applications was assessed, in particular the ability to reproduce biological inactivation (6-log reduction) of commercially available rapid biological indicators in representative operational scenarios and their relative sensitivity to other biological and chemical indicators. Objectives: The primary objective of this study was to describe observations and results of formaldehyde fumigation efficacy in high-containment laboratories. Results: Biological indicators placed throughout laboratory spaces, including ventilation ductwork at distances up to 15 meters, inside pieces of equipment and in lengths of pipe, were mostly negative, demonstrating the ability of formaldehyde to reach the interior and external surfaces tested. Dwell times as short as 10 minutes were shown to be sufficient in barrier decontamination equipment for the fumigation of personal computers. Furthermore, a pipework bore:length ratio of 1:1500 was proven too great a challenge. Indicators placed after extracting HEPA filters in microbiological safety cabinets (MBSCs) were also successfully fumigated (at room temperature) relying solely on diffusion and in the cabinet workspace at 10°C to 12°C. In addition, pressures of up to 900 Pa were experienced in low-leakage laboratory spaces during fumigation. Conclusions: Formaldehyde fumigation was shown to be effective in a variety of scenarios representing operational activities thereby giving process assurance.
RESUMO
BACKGROUND: The recent reclassification of formaldehyde as a presumed carcinogen prompted the investigation into the comparative efficacy of hydrogen peroxide as a fumigant in microbiological safety cabinets. INTRODUCTION: The aim of the study was to quantify the biocidal efficacy of formaldehyde fumigation, including variables such as exposure time and concentration, and then to compare this to the biocidal efficacy achieved from a hydrogen peroxide vapor fumigation system. The study also investigated the ability of both fumigants to permeate the microbiological safety cabinet (MBSC), including the workspace, under the work tray, and after the HEPA filters. Furthermore, the effect of organic soiling on efficacy was also assessed. Infectious bronchitis virus (IBV) was used as the biological target to develop this study model. METHODS: A model using IBV was developed to determine the efficacy of formaldehyde and hydrogen peroxide as fumigants. Virus was dried on stainless steel discs, and variables including concentration, time, protein soiling, and location within an MBSC were assessed. RESULTS: It was demonstrated that formaldehyde fumigation could achieve a 6-log reduction in the titer of the virus throughout the cabinet, and high protein soiling in the presentation did not affect efficacy. Appropriate cycle parameters for the hydrogen peroxide system were developed, and when challenged with IBV, it was shown that vaporized hydrogen peroxide could achieve an equal 6-log titer reduction as formaldehyde within the cabinet workspace and overcome the presence of soiling. CONCLUSION: Hydrogen peroxide was demonstrated to be a viable alternative to formaldehyde under most situations tested. However, the hydrogen peroxide system did not achieve an equal titer reduction above the cabinet's first HEPA filter using the cabinet workspace cycle, and further optimization of the hydrogen peroxide cycle parameters, including pulsing of the cabinet fans, may be required to achieve this.
RESUMO
Airway management following severe gasoline burn injury can be difficult. Because patients with severe burns may be treated at a variety of hospitals that provide emergent care, it is valuable for Certified Registered Nurse Anesthetists who work in such facilities to have an understanding of the care of these patients. Airway management is an extremely important consideration in the care of burn victims. If not done in a timely manner, lethal complications may result. This article reports the experience of caring for a female who was involved in an altercation, doused with gasoline, and set on fire. Consequently, airway obstruction developed and progressively worsened. Airway management interventions began with bag-valve-mask-assisted ventilation and progressed through orotracheal intubation attempts, attempts to insert a laryngeal mask airway, cricothyrotomy, emergency tracheostomy, and surgical tracheostomy.
Assuntos
Manuseio das Vias Aéreas/métodos , Queimaduras/terapia , Gasolina/efeitos adversos , Máscaras Laríngeas , Enfermeiros Anestesistas , Adulto , Queimaduras/diagnóstico , Queimaduras/enfermagem , Feminino , Humanos , Índice de Gravidade de DoençaRESUMO
Better Than Chocolate investigates the inclusion of transgendered women in lesbian space. The film makes a strong statement that it is logical and natural to welcome trans women to the lesbian community, and that those who reject this inclusion are old-fashioned, violent, or both. It is my assertion that the film makes this statement at the expense of both those who have nuanced reservations toward trans inclusion and those transwomen who desire inclusion into lesbian communities but aren't hyperfeminine.