Comparison of basal broth media for the optimal laboratory recovery of Campylobacter jejuni and Campylobacter coli.

Abstract

Campylobacter species are the most common known bacterial cause of acute diarrhoeal disease and incidences are increasing yearly in Ireland. Concern is expressed that this increase may be due to poor laboratory techniques in recognising these organisms as they are fastidious and technically demanding to culture. To evaluate and compare the efficacy of seven commercially available basal broth media for the laboratory cultivation of thermophilic C. jejuni and C. coli isolated from foods and clinical specimens, as well as for optimal laboratory passage. Four strains of Campylobacter spp., including two C. jejuni and two C. coli isolated from pigs were used to compare the quantitative growth of cells on seven commercially available basal culture broths. These included nutrient broth (NB), nutrient broth no. 2 (NB2), Mueller-Hinton broth (MH), brucella broth (BB), brain heat infusion broth supplemented with 0.6% (w/v) yeast extract (BHIYE), tryptone soya broth supplemented with 0.6% (w/v) yeast extract (TSBYE) and Campylobacter broth (KAMPY) employing a spectrophotometrical growth assay model. Mean absorbance results of the broth media comparison for each strain and statistical analysis of variance allowed the basal media to be ranked into the order, based on proliferation of organisms: BHIYE > TSBYE > BB > NB2 > MHB > KAMPY > NB CONCLUSION: These studies support laboratory employment of either BHIYE or TSBYE for optimal recovery of C. jejuni and C. coli and avoidance of nutrient broth.