The testing of antibodies raised against poultry red mite antigens in an in vitro feeding assay; preliminary screen for vaccine candidates

AbstractAlthough artificial feeding models for the poultry red mite (Dermanyssus gallinae) most frequently use biological membranes consisting of day-old chick skin, there are ethical considerations associated with the use of skin. The few studies reported in the literature that have investigated the use of synthetic membranes to feed D. gallinae in vitro have reported limited success. The current study describes an investigation into the use of synthetic membranes made from either Nescofilm® or rayon and silicone, used either alone or in combination with different feather or skin extracts, as well as the use of capillary tubes. In all, 12 different treatments were used, and the feeding rate of D. gallinae was compared to that of day-old chick skin. Allowing mites to feed on a membrane consisting of Nescofilm with a skin extract resulted in the highest proportion of mites feeding (32.3%), which was not significantly different to the feeding rate of mites on day-old chick skin (38.8%). This study confirms that synthetic membranes can be used to feed D. gallinae artificially. Further optimization of the membrane and mite storage conditions is still necessary, but the study demonstrates a proof of concept.

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Ability of a proteinase inhibitor mixture to kill poultry red mite, Dermanyssus gallinae in an in vitro feeding system

Veterinary Parasitology ◽

10.1016/j.vetpar.2006.05.013 ◽

2006 ◽

Vol 141 (3-4) ◽

pp. 380-385 ◽

Cited By ~ 22

Author(s):

R. McDevitt ◽

A.J. Nisbet ◽

J.F. Huntley

Keyword(s):

Proteinase Inhibitor ◽

Dermanyssus Gallinae ◽

Feeding System ◽

Poultry Red Mite ◽

In Vitro Feeding

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An improved method for in vitro feeding of adult female Dermanyssus gallinae (poultry red mite) using Baudruche membrane (goldbeater’s skin)

Parasites & Vectors ◽

10.1186/s13071-020-04471-x ◽

2020 ◽

Vol 13 (1) ◽

Author(s):

Francesca Nunn ◽

Jessica Baganz ◽

Kathryn Bartley ◽

Sarah Hall ◽

Stewart Burgess ◽

...

Keyword(s):

Adult Female ◽

Egg Laying ◽

Blood Type ◽

Dermanyssus Gallinae ◽

Feeding Rates ◽

Poultry Red Mite ◽

Polyester Mesh ◽

In Vitro Feeding

Abstract Background Dermanyssus gallinae, or poultry red mite (PRM), is an important ectoparasite in laying hen, having a significant effect on animal welfare and potentially causing economic loss. Testing novel control compounds typically involves in vitro methodologies before in vivo assessments. Historically, in vitro methods have involved PRM feeding on hen blood through a membrane. The use of hen blood requires multiple procedures (bleeds) to provide sufficient material, and the use of a larger species (e.g. goose) could serve as a refinement in the use of animals in research. Methods The in vitro feeding device used was that which currently employs a Parafilm™ M membrane (Bartley et al.: Int J Parasitol. 45:819–830, 2015). Adult female PMR were used to investigate any differences in mite feeding, egg laying and mortality when fed goose or hen blood. Effects on these parameters when PRM were fed through either the Parafilm™ M membrane or the Baudruche membrane alone or through a combination of the membrane with an overlaid polyester mesh were tested using goose blood. Results Poultry red mites fed equally well on goose or hen blood through the Parafilm™ M membrane, and there were no significant differences in mortality of PRM fed with either blood type. A significant increase (t test: t = 3.467, df = 4, P = 0.03) in the number of eggs laid per fed mite was observed when goose blood was used. A 70% increase in PRM feeding was observed when the mites were fed on goose blood through a Baudruche membrane compared to when they were fed goose blood through the Parafilm™ M membrane. The addition of an overlaid polyester mesh did not improve feeding rates. A significant increase (analysis of variance: F(3, 20) = 3.193, P = 0.04) in PRM egg laying was observed in mites fed on goose blood through the Baudruche membrane compared to those fed goose blood through the Parafilm™ M membrane. A mean of 1.22 (standard error of the mean ± 0.04) eggs per fed mite was obtained using the Baudruche feeding device compared to only 0.87 (SEM ± 0.3) eggs per fed mite using the Parafilm™ M device when neither was combined with a polyester mesh overlay. Conclusion The in vitro feeding of adult female PRM can be readily facilitated through the use of goose blood in feeding devices with the Baudruche membrane.

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An Improved Method for in Vitro Feeding of Dermanyssus Gallinae (Poultry Red Mite) Using Baudruche Membrane (Goldbeater’s Skin).

10.21203/rs.3.rs-57341/v1 ◽

2020 ◽

Author(s):

Francesca G Nunn ◽

Jessica Baganz ◽

Kathryn Bartley ◽

Sarah Hall ◽

Stewart Burgess ◽

...

Keyword(s):

Egg Laying ◽

Blood Type ◽

Dermanyssus Gallinae ◽

Feeding Rates ◽

Poultry Red Mite ◽

Polyester Mesh ◽

Mite Feeding ◽

In Vitro Feeding

Abstract Background: Dermanyssus gallinae, or poultry red mite (PRM), is one of the most economically important ectoparasites in laying hens worldwide with infestations leading to both welfare and economic issues. Research into the testing and validation of novel vaccines and systemic acaricides to control PRM initially requires the use of in vitro methodologies before using in vivo assessments. In vitro methods to date have either involved PRM feeding on hen blood through biological membranes such as chick skin, which can be difficult to obtain and variable in quality, or through synthetic membranes that are unsatisfactory due to breakage and lack of natural feeding cues. The use of hen blood in these systems also requires multiple procedures (bleeds) to provide sufficient material for experimental replicates and the potential for using other species, from which larger blood volumes can be withdrawn in a single procedure (e.g. geese), could improve this technique as a refinement in the use of animals in research.Methods: Using adult female PRM, an initial experiment with an existing in vitro feeding device employing a Parafilm™ M membrane [1] was used to investigate any differences in mite feeding, egg laying and mortality when fed goose or hen blood. Subsequently, any effects on these parameters when PRM were fed through two different membranes; Parafilm™ M and Baudruche membrane, and a combination of these membranes with an overlaid polyester mesh to promote mite attachment, were then tested using goose blood as the food source.Results: PRM fed equally well on goose or hen blood through a Parafilm™ M membrane and there were no statistically significant differences in mortality of PRM fed with either blood type, although a significant increase (p = 0.03) in eggs laid per fed mite when using goose blood was demonstrated, indicating that goose blood is a satisfactory replacement for hens blood. A 70% increase in PRM feeding was observed when mites were fed on goose blood through a Baudruche membrane when compared to the Parafilm™ M membrane. Addition of an overlaid polyester mesh did not further improve feeding rates on either membrane. A significant increase (p = 0.04) in PRM egg laying was observed in mites fed on goose blood through Baudruche membrane, compared to those fed through Parafilm™ M. A mean of 1.22 eggs per fed mite was obtained using the Baudruche feeding device compared to only 0.87 eggs per fed mite using the Parafilm™ M device when neither had a polyester mesh overlay. It was noted that PRM feeding through Baudruche membrane had fed to repletion when compared to those fed through Parafilm™ M.Conclusion: The in vitro feeding of poultry red mite can be readily facilitated through the use of goose blood in feeding devices with Baudruche membrane.

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An improved method for in vitro feeding of adult female Dermanyssus gallinae (poultry red mite) using Baudruche membrane (goldbeater’s skin).

10.21203/rs.3.rs-57341/v2 ◽

2020 ◽

Author(s):

Francesca G Nunn ◽

Jessica Baganz ◽

Kathryn Bartley ◽

Sarah Hall ◽

Stewart Burgess ◽

...

Keyword(s):

Adult Female ◽

Egg Laying ◽

Impact Testing ◽

Blood Type ◽

Dermanyssus Gallinae ◽

Feeding Rates ◽

Poultry Red Mite ◽

Polyester Mesh ◽

In Vitro Feeding

Abstract Background Dermanyssus gallinae , or poultry red mite (PRM), is an important ectoparasite in laying hens, having a significant welfare and economic impact. Testing novel control compounds typically involves in vitro methodologies before in vivo assessments. Historically, in vitro methods have involved PRM feeding on hen blood through a membrane. The use of hen blood requires multiple procedures (bleeds) to provide sufficient material and the use of a larger species (e.g. geese), could serve as a refinement in the use of animals in research. Methods The existing in vitro feeding device, employing a Parafilm™ M membrane [1] and adult females was used to investigate any differences in mite feeding, egg laying and mortality when fed goose or hen blood. Effects on these parameters when PRM were fed through either; Parafilm™ M, Baudruche membrane, and a combination of these with an overlaid polyester mesh were then tested using goose blood. Results PRM fed equally well on goose or hen blood through a Parafilm™ M membrane, no significant differences in mortality of PRM fed with either blood type was demonstrated. A significant increase (t-test: t =3.467, df =4, P = 0.03). in eggs laid per fed mite when using goose blood was demonstrated. A 70% increase in PRM feeding was observed when mites were fed on goose blood through a Baudruche membrane when compared to the Parafilm™ M membrane. Addition of an overlaid polyester mesh did not improve feeding rates. A significant increase (ANOVA: F (3, 20) =3.193, P = 0.04) in PRM egg laying was observed in mites fed on goose blood through Baudruche membrane, compared to those fed through Parafilm™ M. A mean of 1.22 (SEM ± 0.04) eggs per fed mite was obtained using the Baudruche feeding device compared to only 0.87 (SEM ±0.3) eggs per fed mite using the Parafilm™ M device when neither had a polyester mesh overlay. Conclusion The in vitro feeding of adult female poultry red mite can be readily facilitated through the use of goose blood in feeding devices with Baudruche membrane.

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Evaluation of the Safety and Immune Efficacy of Recombinant Human Respiratory Syncytial Virus Strain Long Live Attenuated Vaccine Candidates

Virologica Sinica ◽

10.1007/s12250-021-00345-3 ◽

2021 ◽

Author(s):

Li-Nan Wang ◽

Xiang-Lei Peng ◽

Min Xu ◽

Yuan-Bo Zheng ◽

Yue-Ying Jiao ◽

...

Keyword(s):

Respiratory Syncytial Virus ◽

Gene Deletion ◽

Human Respiratory Syncytial Virus ◽

Temperature Sensitive ◽

T7 Promoter ◽

Vaccine Candidates ◽

Rsv Infection ◽

Syncytial Virus

AbstractHuman respiratory syncytial virus (RSV) infection is the leading cause of lower respiratory tract illness (LRTI), and no vaccine against LRTI has proven to be safe and effective in infants. Our study assessed attenuated recombinant RSVs as vaccine candidates to prevent RSV infection in mice. The constructed recombinant plasmids harbored (5′ to 3′) a T7 promoter, hammerhead ribozyme, RSV Long strain antigenomic cDNA with cold-passaged (cp) mutations or cp combined with temperature-sensitive attenuated mutations from the A2 strain (A2cpts) or further combined with SH gene deletion (A2cptsΔSH), HDV ribozyme (δ), and a T7 terminator. These vectors were subsequently co-transfected with four helper plasmids encoding N, P, L, and M2-1 viral proteins into BHK/T7-9 cells, and the recovered viruses were then passaged in Vero cells. The rescued recombinant RSVs (rRSVs) were named rRSV-Long/A2cp, rRSV-Long/A2cpts, and rRSV-Long/A2cptsΔSH, respectively, and stably passaged in vitro, without reversion to wild type (wt) at sites containing introduced mutations or deletion. Although rRSV-Long/A2cpts and rRSV-Long/A2cptsΔSH displayed temperature-sensitive (ts) phenotype in vitro and in vivo, all rRSVs were significantly attenuated in vivo. Furthermore, BALB/c mice immunized with rRSVs produced Th1-biased immune response, resisted wtRSV infection, and were free from enhanced respiratory disease. We showed that the combination of ΔSH with attenuation (att) mutations of cpts contributed to improving att phenotype, efficacy, and gene stability of rRSV. By successfully introducing att mutations and SH gene deletion into the RSV Long parent and producing three rRSV strains, we have laid an important foundation for the development of RSV live attenuated vaccines.

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Plectin ensures intestinal epithelial integrity and protects colon against colitis

Mucosal Immunology ◽

10.1038/s41385-021-00380-z ◽

2021 ◽

Vol 14 (3) ◽

pp. 691-702

Author(s):

Alzbeta Krausova ◽

Petra Buresova ◽

Lenka Sarnova ◽

Gizem Oyman-Eyrilmez ◽

Jozef Skarda ◽

...

Keyword(s):

Mechanical Stability ◽

Intestinal Barrier ◽

Intercellular Junctions ◽

Protein Profiling ◽

Cell Junctions ◽

Intestinal Barrier Function ◽

Intestinal Epithelial ◽

Critical Determinant ◽

In Vitro Feeding

AbstractPlectin, a highly versatile cytolinker protein, provides tissues with mechanical stability through the integration of intermediate filaments (IFs) with cell junctions. Here, we hypothesize that plectin-controlled cytoarchitecture is a critical determinant of the intestinal barrier function and homeostasis. Mice lacking plectin in an intestinal epithelial cell (IEC; PleΔIEC) spontaneously developed colitis characterized by extensive detachment of IECs from the basement membrane (BM), increased intestinal permeability, and inflammatory lesions. Moreover, plectin expression was reduced in the colons of ulcerative colitis (UC) patients and negatively correlated with the severity of colitis. Mechanistically, plectin deficiency in IECs led to aberrant keratin filament (KF) network organization and the formation of dysfunctional hemidesmosomes (HDs) and intercellular junctions. In addition, the hemidesmosomal α6β4 integrin (Itg) receptor showed attenuated association with KFs, and protein profiling revealed prominent downregulation of junctional constituents. Consistent with the effects of plectin loss in the intestinal epithelium, plectin-deficient IECs exhibited remarkably reduced mechanical stability and limited adhesion capacity in vitro. Feeding mice with a low-residue liquid diet that reduced mechanical stress and antibiotic treatment successfully mitigated epithelial damage in the PleΔIEC colon.

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Comparison of in vivo and in vitro survival and fecundity rates of the poultry red mite, Dermanyssus gallinae

Research in Veterinary Science ◽

10.1016/j.rvsc.2009.08.002 ◽

2010 ◽

Vol 88 (2) ◽

pp. 279-280 ◽

Cited By ~ 6

Author(s):

S. Arkle ◽

D.R. George ◽

J.H. Guy ◽

O.A.E. Sparagano

Keyword(s):

Dermanyssus Gallinae ◽

Poultry Red Mite ◽

In Vitro Survival

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Comparison of Four SARS-CoV-2 Neutralization Assays

Vaccines ◽

10.3390/vaccines9010013 ◽

2020 ◽

Vol 9 (1) ◽

pp. 13

Author(s):

Lydia Riepler ◽

Annika Rössler ◽

Albert Falch ◽

André Volland ◽

Wegene Borena ◽

...

Keyword(s):

Vesicular Stomatitis Virus ◽

Neutralizing Antibodies ◽

The Other ◽

In Vitro Assays ◽

The Novel ◽

Effective Protection ◽

Vaccine Candidates ◽

Vesicular Stomatitis ◽

Novel Coronavirus

Neutralizing antibodies are a major correlate of protection for many viruses including the novel coronavirus SARS-CoV-2. Thus, vaccine candidates should potently induce neutralizing antibodies to render effective protection from infection. A variety of in vitro assays for the detection of SARS-CoV-2 neutralizing antibodies has been described. However, validation of the different assays against each other is important to allow comparison of different studies. Here, we compared four different SARS-CoV-2 neutralization assays using the same set of patient samples. Two assays used replication competent SARS-CoV-2, a focus forming assay and a TCID50-based assay, while the other two assays used replication defective lentiviral or vesicular stomatitis virus (VSV)-based particles pseudotyped with SARS-CoV-2 spike. All assays were robust and produced highly reproducible neutralization titers. Titers of neutralizing antibodies correlated well between the different assays and with the titers of SARS-CoV-2 S-protein binding antibodies detected in an ELISA. Our study showed that commonly used SARS-CoV-2 neutralization assays are robust and that results obtained with different assays are comparable.

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