Effect of Agitation Rate on Growth Yield and Virulence of Bordetella pertussis Strain 509 in Lab Scale Cultivation

Table of Contents

Introduction

Material and Methods

Preparation of Media

Opacity Test

Sterility Test

Effect of Agitation

Mouse Weight Gain Test

LPF Activity

Filamentous Haemagglutinin (FHA) Adherence Activity towards Vero & CHO Cell Line

Results and Discussion

Conclusion

Research Objectives and Key Themes

The primary objective of this study is to investigate the impact of various agitation rates on the growth yield and virulence properties of Bordetella pertussis strain 509 during lab-scale cultivation to optimize vaccine production quality.

• Optimization of agitation rates in bioreactors
• Evaluation of shear stress on bacterial cell viability
• Assessment of vaccine toxicity via Mouse Weight Gain Tests (MWGT)
• Analysis of filamentous haemagglutinin (FHA) adherence properties
• Determination of Lymphocytosis Promoting Factor (LPF) activity

Excerpt from the Publication

Summary of Chapters

Introduction: Provides background on the role of vaccines in preventing pertussis and describes the biological characteristics and pathogenicity of Bordetella pertussis.

Material and Methods: Details the experimental procedures, including medium preparation, cultivation parameters, sterility checks, and specific toxicity testing protocols such as MWGT and LPF assays.

Results and Discussion: Presents and analyzes the experimental data regarding growth yields, pH levels, and toxicity tests under different agitation speeds, highlighting the correlation between shear stress and vaccine quality.

Conclusion: Summarizes the findings by recommending an optimal agitation rate of 140 rpm for producing high-quality, non-toxic vaccine cultures while discouraging higher speeds due to cell lysis.

Keywords

Agitation rate, Bordetella pertussis, Endotoxin, Toxicity, Vaccine production, Shear stress, Growth yield, Mouse Weight Gain Test, LPF, FHA, Cell adherence, Bioreactor, Virulence, Immunogenicity, Cultivation.

Frequently Asked Questions

What is the core focus of this research?

The study examines how different agitation rates during the cultivation of Bordetella pertussis influence the yield and the virulence profile of the resulting vaccine.

What are the primary themes addressed in the paper?

The paper covers cultivation parameters, shear stress analysis, vaccine toxicity testing, and the functional adherence properties of bacterial cells.

What is the main research question?

The researchers sought to determine the optimal agitation rate for B. pertussis cultivation that maximizes growth yield while minimizing the toxicity caused by cell lysis.

Which scientific methods were employed?

The study utilized standard microbiological culture techniques, Mouse Weight Gain Tests (MWGT), LPF activity assays, and fluorescence microscopy to evaluate cell adherence.

What topics are discussed in the main body?

The main body details the preparation of media, the effect of mechanical shear on bacteria, the evaluation of vaccine purity, and the correlation between agitation speeds and animal test results.

How can this work be described using keywords?

Key terms include agitation rate, Bordetella pertussis, endotoxin, toxicity, vaccine production, shear stress, and cell adherence.

Why is higher agitation considered detrimental to vaccine quality?

Higher agitation causes mechanical shear stress, leading to cell lysis and the release of endotoxins, which increase the toxicity of the vaccine.

What significance does the Mouse Weight Gain Test have in this study?

The MWGT is used as a regulatory benchmark to ensure the vaccine meets safety standards; failure to gain sufficient weight indicates the culture is too toxic for use.

How does shear stress affect the adherence of FHA cells?

Shear stress damages the Filamentous Haemagglutinin (FHA) protein on the surface of the bacteria, significantly reducing its ability to adhere to target cell lines like Vero and CHO.