Selective medium for thermophilic campylobacters including Campylobacter upsaliensis

Area of Science:

• Microbiology
• Clinical Diagnostics
• Bacteriology

Background:

• Thermophilic Campylobacter species are significant human pathogens.
• Accurate isolation of Campylobacter from fecal samples is crucial for diagnosis.
• Campylobacter upsaliensis presents unique isolation challenges.

Purpose of the Study:

• To develop a selective supplement for improved recovery of thermophilic Campylobacter spp. from fecal specimens.
• To evaluate a novel selective agar medium, CAT medium, for Campylobacter isolation.
• To specifically enhance the recovery of Campylobacter upsaliensis.

Main Methods:

• Determined minimum inhibitory concentrations (MICs) of cefoperazone and teicoplanin for Campylobacter and Enterobacteriaceae.
• Formulated CAT medium using campylobacter blood-free selective agar base with specific antibiotics.
• Compared CAT medium against modified CCDA for isolating Campylobacter spp. from 7000 human fecal specimens and 45 spiked samples.

Main Results:

• CAT medium demonstrated comparable isolation rates for most thermophilic Campylobacter spp. compared to modified CCDA.
• CAT medium uniquely recovered four out of five strains of Campylobacter upsaliensis from clinical fecal samples.
• Recovery of Campylobacter upsaliensis from spiked feces was significantly increased on CAT medium (35% to over 200-fold).

Conclusions:

• CAT selective agar is a suitable alternative medium for the isolation of thermophilic Campylobacter species, including Campylobacter upsaliensis, from fecal specimens.
• The developed CAT medium offers enhanced recovery for Campylobacter upsaliensis.
• This advancement aids in the accurate diagnosis and study of Campylobacter infections.