Aerobic Growth of Campylobacter in Media Supplemented with C3-Monocarboxylates and C4-Dicarboxylates†

Abstract

Experiments were conducted to examine aerobic growth of Campylobacter spp. in basal media supplemented with C4-dicarboxylates (fumarate, succinate, or malate) and C3-monocarboxylates (pyruvate or lactate). Basal medium was supplemented with 30 mM fumarate, succinate, or malate and 0 to 100 mM lactate or pyruvate; inoculated with 106 CFU/ml of Campylobacter coli, Campylobacter fetus, or Campylobacter jejuni; then incubated aerobically at 37°C for 72 h. Optical density (OD) of cultures was measured at 600 nm during incubation. The effect of adding 0 to 0.20% agar and 0 to 0.10% sodium bicarbonate (NaHCO3) to media supplemented with 30 mM fumarate and 100 mM pyruvate on Campylobacter growth was also determined. Finally, CFU per milliliter of Campylobacter spp. recovered from media containing 30 mM fumarate, 100 mM pyruvate, 0.15% agar, and 0.05% NaHCO3 was determined after inoculated media were incubated aerobically or microaerophilically. Results indicated that the OD600 of Campylobacter cultures incubated in media supplemented with C4-dicarboxylates and C3-monocarboxylates was generally significantly (P ≤ 0.05) greater than growth of cultures incubated in media supplemented with a C4-dicarboxylate only. The OD600 of cultures of Campylobacter spp. grown in media supplemented with fumarate and pyruvate was higher (P ≤ 0.05) when agar was added, and the addition of NaHCO3 produced an additional increase (P ≤ 0.05) in the OD600 of most of the isolates. There was also a 5- to 6-log increase in Campylobacter spp. recovered from media supplemented with 30 mM fumarate, 100 mM pyruvate, 0.15% agar, and 0.05% NaHCO3 that was inoculated 103 CFU/ml and incubated aerobically or microaerophilically. Findings indicate that this medium might provide an alternative to incubating Campylobacter spp. microaerophilically, thus eliminating costs and training required for producing special atmospheres for culturing the pathogen.