Location: Poultry Microbiological Safety and Processing Research UnitTitle: Media for aerobic recovery of campylobacter from mixed bacterial cultures
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/22/2018
Publication Date: 9/3/2018
Citation: Hinton Jr, A., Cox Jr, N.A. 2018. Media for aerobic recovery of campylobacter from mixed bacterial cultures. Meeting Abstract. pg. 396.
Interpretive Summary: none
Technical Abstract: A non-selective medium for culturing Campylobacter aerobically was recently described. The objective of the present study was to determine if a selective medium could be formulated by supplementing the new medium with the Bolton antibiotic mixture. Basal medium containing beef extract, 50 g; tryptose, 10 g; soluble starch, 10 g; sodium lactate, 3.0 g; and agar, 0.5 g dissolved in 900 ml of distilled water was dispensed in 9 ml aliquots in screw capped test tubes and autoclaved. The medium was cooled, and 1 ml of 1.5% sterile sodium bicarbonate was added. The selective medium was prepared by adding the Bolton antibiotic mixture to the basal medium. Both media were transferred to 25 ml culture flasks before inoculation with bacteria. Mixed bacterial cultures were prepared by adding either Campylobacter fetus, Campylobacter coli, Campylobacter jejuni, or Campylobacter lari to bacterial suspensions containing Enterococcus faecalis, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa Salmonella Kentucky, and Staphylococcus aureus. Separate culture flasks containing10 ml of the basal medium or the selective medium were inoculated with the mixed cultures, then incubated aerobically at 37C for 48 h. After incubation, Campylobacter were enumerated on blood agar with Blaser-Wang antibiotic mixture with microaerobic incubation. Aerobic incubation was used to enumerate E. faecalis on m-Enterococcus agar, E. coli on Levine EMB agar; L. monocytogenes on Listeria Selective Agar, P. aeruginosa on Pseudomonas agar base with Pseudomonas C-F-C supplement, Salmonella Kentucky on XLT4 agar, and S. aureus on Mannitol Salts agar. Results indicated that all isolates were recovered from basal medium after aerobic incubation and that significantly (p < 0.05) fewer Campylobacter spp. were recovered than all other isolates, except S. aureus, in the mixed culture. However, after incubation in media supplemented with the Bolton antibiotic mixture, significantly more Campylobacter than the other bacterial isolates were recovered. Furthermore, there was no significant growth of the other bacteria in the mixed culture and no E. coli, Salmonella Kentucky, or S. aureus were recovered in most experiments. Findings indicate that supplementing the basal medium with the Bolton mixture produces a selective medium that can be used to aerobically isolate Campylobacter from samples containing other bacteria.