scholarly journals Simplified Method for Efficient Intravascular Inoculation of Chicken Embryos

1976 ◽  
Vol 4 (1) ◽  
pp. 104-105
Author(s):  
C. L. Kelling ◽  
I. A. Schipper

The simple syringe-stabilizer unit described in this note provides a means for rapid intravascular inoculation of embryonated chicken eggs with minimal embryonic death from vascular trauma.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marloes Heijne ◽  
Martina Jelocnik ◽  
Alexander Umanets ◽  
Michael S. M. Brouwer ◽  
Annemieke Dinkla ◽  
...  

AbstractChlamydia gallinacea is an obligate intracellular bacterium that has recently been added to the family of Chlamydiaceae. C. gallinacea is genetically diverse, widespread in poultry and a suspected cause of pneumonia in slaughterhouse workers. In poultry, C. gallinacea infections appear asymptomatic, but studies about the pathogenic potential are limited. In this study two novel sequence types of C. gallinacea were isolated from apparently healthy chickens. Both isolates (NL_G47 and NL_F725) were closely related to each other and have at least 99.5% DNA sequence identity to C. gallinacea Type strain 08-1274/3. To gain further insight into the pathogenic potential, infection experiments in embryonated chicken eggs and comparative genomics with Chlamydia psittaci were performed. C. psittaci is a ubiquitous zoonotic pathogen of birds and mammals, and infection in poultry can result in severe systemic illness. In experiments with embryonated chicken eggs, C. gallinacea induced mortality was observed, potentially strain dependent, but lower compared to C. psittaci induced mortality. Comparative analyses confirmed all currently available C. gallinacea genomes possess the hallmark genes coding for known and potential virulence factors as found in C. psittaci albeit to a reduced number of orthologues or paralogs. The presence of potential virulence factors and the observed mortality in embryonated eggs indicates C. gallinacea should rather be considered as an opportunistic pathogen than an innocuous commensal.


2021 ◽  
Author(s):  
Frederick Porter

Introduction Vaccines are biological products that elicit a protective immune response. The details of the manufacturing processes are varied depending on the particular characteristics of the vaccine. There are classically, three basic types of vaccines against viral and bacterial pathogens (For mRNA-, DNA- and vector-vaccines see Chapters 7, 8, 9): Live-attenuated. Killed (non-live). Subunit. “Classical” Vaccine Production The basic classical process includes 5 phases: expression, harvest, inactivation, purification, formulation. The expression systems for viral and bacterial vaccines are distinct. Bacterial expression is performed in fermenters. Viral vaccines are produced in animal cell culture or embryonated chicken eggs. Processes for whole viral or bacterial vaccines often involve only limited processing after expression. Subunit vaccines routinely require the most purification to separate the product from other contaminants. Challenges Challenges for bacterial vaccines include testing to ensure the safety and efficacy of the product. Inactivation procedures need to be carefully controlled. Live attenuated vaccines need to be tested to ensure the vaccine strains are still safe and effective. Viral vaccines require testing to ensure foreign infectious agents are not introduced during processing. Both cultured cells and egg present risks for infection. Live viral vaccines and gene vectors need to be carefully engineered and tested to minimize safety concerns. Highly variable vaccine targets such as influenza need to be re-adapted to current circulating strains.


Author(s):  
P. Gebhardt ◽  
L. Würbach ◽  
A. Heidrich ◽  
L. Heinrich ◽  
M. Walther ◽  
...  

Viruses ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 452 ◽  
Author(s):  
Martin Langenmayer ◽  
Anna-Theresa Lülf-Averhoff ◽  
Silvia Adam-Neumair ◽  
Gerd Sutter ◽  
Asisa Volz

The Modified Vaccinia virus Ankara (MVA) is a highly attenuated vaccinia virus serving as a promising vector vaccine platform to develop vaccines against infectious diseases. In contrast to the well-established replication deficiency and safety of MVA in mammals, much less is known about MVA infection in avian hosts. Here, we used a recombinant MVA expressing fluorescent reporter proteins under transcriptional control of specific viral early and late promoters to study in vivo tropism, distribution, and pathogenesis of MVA infections in embryonated chicken eggs. The chorioallantoic membrane (CAM) of embryonated chicken eggs was inoculated with recombinant MVA, MVA or phosphate-buffered saline. The infection was analyzed by fluorescence microscopy, histology, immunohistochemistry, and virus titration of embryonic tissues. After infection of the CAM, MVA spread to internal and external embryonic tissues with the liver as a major target organ. Macrophages and hematopoietic cells were identified as primary target cells of MVA infection and may be involved in virus spread. Increasing doses of MVA did not result in increased lesion severity or embryonic death. Despite MVA generalization to embryonic tissues, the CAM seems to be the major site of MVA replication. The absence of considerable organ lesions and MVA-associated mortality highlights an excellent safety profile of MVA in chicken hosts.


2005 ◽  
Vol 79 (11) ◽  
pp. 6763-6771 ◽  
Author(s):  
Bin Lu ◽  
Helen Zhou ◽  
Dan Ye ◽  
George Kemble ◽  
Hong Jin

ABSTRACT The H3N2 influenza A/Fujian/411/02-like virus strains that circulated during the 2003-2004 influenza season caused influenza epidemics. Most of the A/Fujian/411/02 virus lineages did not replicate well in embryonated chicken eggs and had to be isolated originally by cell culture. The molecular basis for the poor replication of A/Fujian/411/02 virus was examined in this study by the reverse genetics technology. Two antigenically related strains that replicated well in embryonated chicken eggs, A/Sendai-H/F4962/02 and A/Wyoming/03/03, were compared with the prototype A/Fujian/411/02 virus. A/Sendai differed from A/Fujian by three amino acids in the neuraminidase (NA), whereas A/Wyoming differed from A/Fujian by five amino acids in the hemagglutinin (HA). The HA and NA segments of these three viruses were reassorted with cold-adapted A/Ann Arbor/6/60, the master donor virus for the live attenuated type A influenza vaccines (FluMist). The HA and NA residues differed between these three H3N2 viruses evaluated for their impact on virus replication in MDCK cells and in embryonated chicken eggs. It was determined that replication of A/Fujian/411/02 in eggs could be improved by either changing minimum of two HA residues (G186V and V226I) to increase the HA receptor-binding ability or by changing a minimum of two NA residues (E119Q and Q136K) to lower the NA enzymatic activity. Alternatively, recombinant A/Fujian/411/02 virus could be adapted to grow in eggs by two amino acid substitutions in the HA molecule (H183L and V226A), which also resulted in the increased HA receptor-binding activity. Thus, the balance between the HA and NA activities is critical for influenza virus replication in a different host system. The HA or NA changes that increased A/Fujian/411/02 virus replication in embryonated chicken eggs were found to have no significant impact on antigenicity of these recombinant viruses. This study demonstrated that the reverse genetics technology could be used to improve the manufacture of the influenza vaccines.


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