Effect of relevant culture parameters on Pertussis Toxin expression by Bordetella pertussis

Genome-Wide Gene Expression Analysis of Bordetella pertussis Isolates Associated with a Resurgence in Pertussis: Elucidation of Factors Involved in the Increased Fitness of Epidemic Strains

“…In this study, we analyzed the genome-wide microarray-based gene expression of a subset of these strains to evaluate the differences in expression between the B. pertussis strains isolated in the Netherlands between 1949 and 2008 carrying a ptxP1 (n = 9) or ptxP3 allele (n = 5). Strains were grown under Bvg+ conditions in a chemically defined growth medium [30], [31] that provides highly reproducible gene expression and bacterial growth results [32]. Triplicate shake flask cultivations (independent cultures) were grown for each strain.…”

“…The starting materials were vials containing 1 ml Verwey medium (RIVM, Bilthoven, Netherlands; chemically undefined) with 20% glycerol and varying OD 590 stored at −80°C. One vial of each strain was used to inoculate a primary 500 ml shake flask containing 200 ml THIJS medium [30], [31] consisting of basic medium and a supplement (1% v/v) that was added to the basic medium shortly before inoculation. Shake flasks were incubated at 35°C on an orbital shaker at 200 RPM.…”

In vitro innate immune cell based models to assess whole cell Bordetella pertussis vaccine quality: A proof of principle

“…This clinical isolate was collected in 1963 and was used for the production of wP vaccine for the national vaccination program of the Netherlands until 2005. All cultures were grown in chemically defined medium [7,8] using a fully instrumented 3 L bench-top bioreactor fitted with a six-bladed Rushton stirrer (Applikon, Schiedam, The Netherlands) with a 2 L working volume. The reactor was inoculated from a pre-culture, seeded at 5% (v/v) and grown at 35 C. After 3e5 reactor volumes steady state was assumed and deliberate downregulation of virulence genes (t ¼ 0) was initiated by adding medium containing 50 mM MgSO 4 , while at the same time MgSO 4 was added directly to the reactor to change the concentration to 50 mM MgSO 4 instantly.…”

Development of improved pertussis vaccine

“…Several pathways deserve to be explored even without there being a universal solution, since each country has a different situation depending on the history of vaccination policy developed in the last decades. One possibility is to promote the use of wP vaccines but with new less reactogenic 34 and improved 35 formulations. However, the return to wP vaccine use would be difficult for the public to accept in countries that switched to aP vaccines due to adverse reactions from wP vaccines.…”