Microaerobic requirements of camplobacter species and related organisms

Abstract

A novel microaerobic incubator in which oxygen, carbon dioxide, hydrogen and nitrogen can be combined at different concentrations was used to investigate the gaseous requirements of Campylobacter species and Arcobacter species.
Optimum gaseous incubation conditions were identified for all test strains. C. coli, C. fetus, C. jejuni, C. lari NCTC 11352, C. upsaliensis and A. butzleri all showed a preference for 2: 5 % (vlv) oxygen and 10% (v/v) carbon dioxide, without the inclusion of hydrogen. C. helveticus, C. hyointestinalis, C. lari NCTC 11928, C. mucosalis and C. sputorum all showed a preference for :~ 5 % (v/v) oxygen, 0 - 10 % (v/v) carbon dioxide and 5 - 9 % (v/v) hydrogen. A. skirrowil showed a preference for :5 1 % oxygen and 9 % hydrogen.
The effect of different gaseous incubation conditions on the cellular morphology of C. jejuni NCTC 11168 was investigated using electron microscopy. The duration of incubation and gas mixture concentration were shown to influence the size of spiral and coccal cells produced. Coccal cells were predominant in the population as the culture aged in gas mixtures containing oxygen and carbon dioxide but no hydrogen. Spiral cells were predominant in cultures after 72 hours incubation in gas mixtures containing hydrogen.
The determination of optimum gaseous incubation conditions for the growth of Campylobacter species and Arcobacter species demonstrated that routine methods for the microaerobic incubation of campylobacters isolated from food, environmental and clinical samples are optimal for C. jejuni, C. coli, some C. lari strains, C. upsaliensis and A. butzleri. This study provides microaerobic incubation conditions with which to investigate the recovery of other species from naturally contaminated samples and demonstrates that different species within the genus Campylobacter and Arcobacter have different optimal gaseous incubation requirements.