In epidemiology, the common measure of virulence is the number of reproduction (R0) defined as the average number of other hosts that the virus will spread to after infecting a single host. The equivalent measurement does not apply to the virulence phage life cycle. The number of bacteriophage progeny released by each infected cell is given by the burst size; when replicated in a healthy, densely growing bacterial culture, the R0 of the phage is essentially equal to its burst size. However, the size of the outbreak alone is not an appropriate indicator of phage virulence. Because phage virulence is inherently difficult to capture completely, Creative Biolabs' researchers have turned to quick but partially insufficient assessment methods. Commonly used techniques for qualitatively measuring virulence are field tests on agar plates and bacteria reduction curves. Spot inspection requires a small sample of a specific phage to be spread on the bacterial culture grown on the top agar lawn. One of the main challenges in the development of phage therapy and the manufacture of phage products is the reliable evaluation of its efficacy, performance, and quality.
Creative Biolabs can provide high-quality phage virulence testing services. We provide different quantitative analyses and qualitative analyses to evaluate phage virulence according to strict requirements. Our services are listed below, but not limited to:
Fig 1. Comparison of virulence Curves (Storms Z J, et al. 2020)
Common techniques for qualitatively measuring virulence are spot tests on agar plates and bacteria reduction curves.
Spot test requires a small sample of a specific phage to be spread on a bacterial culture grown on the top agar lawn. This is a method to quickly test the sensitivity of bacterial strains to various bacteriophages, but it cannot capture the dynamics of infection.
The bacterial reduction curve is obtained by infecting a liquid bacterial culture with bacteriophages and performing periodic optical density measurements. The curve will be reduced compared to the control without bacteriophages. A typical virulence study involves generating a bacterial reduction curve under various conditions and qualitatively comparing which bacterial curve "reduced" the most. The advantage of this method is that it is applicable to any phage that can be cultured in suspension culture.
More parameters are needed to fully quantify virulence; these include incubation period, adsorption efficiency, and host cell growth rate.
Creative Biolabs can meet the needs of customers by providing solutions in food safety on time and on budget. We have in-depth knowledge and experience of the tools and processes involved in the phage projects. Our skilled and dedicated scientific researchers ensure that the most suitable methods and techniques are selected for your project. If necessary, please feel free to contact us.
Please kindly note that our services can only be used to support research purposes (Not for clinical use).
Creative Biolabs is a globally recognized phage company. Creative Biolabs is committed to providing researchers with the most reliable service and the most competitive price.
