Selective medium for growth of Campylobacter in containers incubated aerobically

Authors: Hinton Jr, Arthur

Submitted to: Campylobacter Helicobacter and Related Organisms International Workshop
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2017
Publication Date: 9/10/2017
Citation: Hinton Jr, A. 2017. Selective medium for growth of Campylobacter in containers incubated aerobically [abstract]. Campylobacter Helicobacter and Related Organisms International Workshop. p. 270.

Interpretive Summary: none

Technical Abstract: Introduction. Campylobacter are traditionally cultured in primary containers inside of secondary containers filled with microaerobic atmospheres. Recent findings indicated that media supplemented with optimal concentrations of amino acids, organic acids, and bicarbonate support Campylobacter growth without incubation in microaerobic atmospheres. The goal of the current research was to determine if supplementing this medium with antibiotics would selectively support Campylobacter growth in mixed bacterial cultures. Materials and Methods. A basal medium composed of (g/l), beef extract, 50; tryptose, 10; soluble starch, 10; sodium lactate 3.0; agar, 0.5; and sodium bicarbonate, 0.15 was prepared. The medium was supplemented with no antibiotics (control), Campy-Cefex antibiotics (cycloheximide, 200 mg/l and cefoperazone, 33 mg/l), or Campy-Cefex antibiotics + trimethoprim lactate, 10 mg/l). Ten ml aliquots of media were transferred to 25 ml culture flasks and inoculated with approximately 103/ml of pure cultures of Campylobacter coli, Campylobacter fetus, Campylobacter jejuni, Enterococcus faecalis, Escherichia coli, Listeria monocytogenes, or Salmonella Kentucky or with mixed cultures of a Campylobacter isolate and a non-Campylobacter isolate. After aerobic incubation at 37C for 48 h, Campylobacter were enumerated on blood agar with Blaser-Wang Selective supplement incubated microaerobically for 48 h. Campylobacter isolates were enumerated on the appropriate selective agar medium. Results. Approximately 108 cfu/ml of each Campylobacter spp. was recovered from all media inoculated with pure Campylobacter cultures or mixed cultures, while approximately 109 cfu/ml of non-Campylobacter cultures were recovered from control media inoculated with pure or mixed cultures. E. faecalis was the only non-Campylobacter recovered from media supplemented with Campy-Cefex antibiotics, while no non-Campylobacter were recovered from media supplemented with Campy-Cefex antibiotics + trimethoprim. Conclusion: The recently described medium supplemented with Campy-Cefex antibiotics + trimethoprim can be used to isolate Campylobacter from mixed bacterial cultures in primary containers incubated aerobically. Utilization of this procedure will simplify methodology for isolating Campylobacter.