Preston Campylobacter Supplement ISO

Description

The difference between Preston Mod. and Preston consists in the change of amphotericin instead of cycloheximide.

The complete supplemented medium was specifically formulated to be suitable for isolation of Campylobacter species from all types of specimens (human, animal, avian and environmental).

Technique

Collect, dilute and prepare samples and volumes as required according to specifications, directives, official standard regulations and/or expected results.

Reconstitute the vial with 6 mL of the sterile diluent in aseptic conditions and add it to 475 mL of the medium base cooled to 50 °C, previously supplemented with 25 mL of lysed defibrinated horse or sheep blood.

Do not overheat once supplemented.

Preston Campylobacter Selective Agar Base

Pour the complete medium into plates and inoculate it by streaking or spiral method.

Incubate the plates in microaerophilic conditions at 40-42 °C for 48-72 h.

Campylobacter spp. grow best at 42 °C (except Campylobacter fetus subsp. fetus).

Preston Broth Base

Pour the complete medium into tubes and inoculate it.

Incubate the plates in microaerophilic conditions at 40-42 °C for 48-72 h.

Campylobacter spp. grow best at 42 °C (except Campylobacter fetus subsp. fetus).

Subculture on Preston Campylobacter Selective Agar or Campylobacter Blood-Free Selective Agar.

Incubation times longer than those mentioned above or different incubation temperatures may be required depending on the sample, on the specifications.

Each laboratory must evaluate the results according to their specifications.

Presumptive isolation of Campylobacter sp. must be confirmed by further microbiological and biochemical tests.

Reconstitute the original freeze-dried vial by adding 6 mL of sterile distilled water.

Note: each vial is sufficient to supplement 500 mL of Campylobacter Preston Medium Base (solid or liquid).

Physical/chemical control

Microbiological control

Inoculate 30-300 CFU (productivity), 1000-10,000 CFU (selectivity).

Distribute the complete medium, cooled to 50 °C, into 90 mm plates.

Microaerophilic atmosphere. Incubation at 40-42 °C for 48-72 h.

Sterility control

100 mL TSB and 100 mL Thioglycollate.

Incubation 48 hours at 30-35 °C and 48 hours at 20-25 °C: NO GROWTH.

Check at 7 days after incubation in same conditions.

• BOLTON, F.J. & L. ROBERTSON (1982) A selective medium for isolating Campylobacter jejuni/coli. J. Clin. Pathol. 35:462-467.
• BOLTON, F.J., D. COATES, P.M. HINCHLIFFE & L. ROBERTSON (1983) Comparative of selective media for isolation of Campylobacter jejuni/coli. J. Clin. Pathol. 36:78-83.
• CORRY, J.E.L., H.I. ATABAY, S.J. FORSYTHE & L.P. MANSFIELD (2003) Culture Media for the Isolation of Campylobacters, Helicobacters and Arcobacters, in Corry et al. (Eds) Handbook of Culture Media for Food Microbiology Chap 18 pgs 271-316. Elsevier Science B.V. Amsterdam.
• ISO 10272-1 Standard (2017) Microbiology of the food chain - Horizontal Method for detection and enumeration of Campylobacter spp. - Part 1: Detection method.
• ISO 11133:2014/Amd 1:2018. Microbiology of food, animal feed and water. Preparation, production, storage and performance testing of culture media.