Campylobacter growth rates in four different matrices: broiler caecal material, live birds, Bolton broth, and brain heart infusion broth

Figures & data

Table 1 The strains used to inoculate caecal contents

Strain identity	Isolated from	Species and sequence type/clonal complex (when available)
CJ1	Broiler Farm, UK	Campylobacter jejuni
CJ2	Broiler Farm, UK	Campylobacter jejuni
CC1	Broiler Farm, UK	Campylobacter coli
CC2	Broiler Farm, UK	Campylobacter coli
LK115	Broiler Farm, Ireland – Caeca	Campylobacter jejuni, ST814/cc-661
ST45	Caeca, Ireland	Campylobacter jejuni, ST45/cc-45
LK016	Caeca, Ireland	Campylobacter jejuni, ST257/cc-257
LK014	Caeca, Ireland	Campylobacter jejuni,ST6764/cc-257
LK253	Caeca, Ireland	Campylobacter jejuni, ST6763/cc-661
11168	Human clinical strain	Campylobacter jejuni typed, national collection

Table 2 Growth parameters in Bolton broth, brain heart infusion broth, irradiated caecal contents, and in the birds (in vivo)

		Lag period (h)		Generation time^1 (h)		µmax (generations h^−1)		Maximum concentration observed
Matrix	Initial concentration (log10 CFU/g)	Mean	Range	Mean	Range	Mean	Range	Mean	Range
Bolton broth	1.0	6.6^a2	2.3–9.0	2.1^a	1.0–3.5	0.7^a	0.1–1.1	9.6^a log10 CFU/ml	7.5–10.7 CFU/ml
Brain Heart Infusion broth	1.0	6.7^a	3.1–8.6	2.2^a	1.0–3.6	0.8^a	0.3–4.4	9.9^a log10 CFU/ml	6.2–10.8 CFU/ml
Caecal (in vitro)	1.0	12.6^b	6.5–20.5	3.1^b	1.2–5.1	0.4^b	0.1–0.9	7.8^b log10 CFU/g	5.3–9.9 CFU/ml
Broilers (in vivo)	Unknown	31.3^c	NA	6.7^c	NA	2.0^c	NA	7.4^b log10 CFU/g	NA

NA=not applicable.

¹Generation time (early lag and exponential phase).

²Numbers with the same superscript letter are not significantly different (p<0.05).