Variation in Campylobacter Multilocus Sequence Typing Subtypes from Chickens as Detected on Three Plating Media

Area of Science:

• Food Microbiology
• Bacteriology
• Poultry Science

Background:

• Campylobacter jejuni and Campylobacter coli are leading causes of bacterial gastroenteritis globally.
• Accurate detection and subtyping of Campylobacter are crucial for food safety and epidemiological surveillance.
• Selective plating media are commonly used for isolating Campylobacter from food matrices, but their subtype selectivity is not fully understood.

Purpose of the Study:

• To compare the ability of three selective Campylobacter plating media (Campy-Cefex, Campy Line, and RF Campylobacter jejuni/coli agars) to detect different subtypes of Campylobacter jejuni and Campylobacter coli.
• To determine if specific media exhibit bias towards certain Campylobacter subtypes in naturally contaminated chicken samples.

Main Methods:

• Samples of ceca and carcasses from 50 broiler flocks were analyzed.
• Campylobacter was cultured and isolated using three selective media: Campy-Cefex, Campy Line, and RF Campylobacter jejuni/coli agars.
• Isolates from positive samples were subjected to full genome sequencing and multilocus sequence typing (MLST) for subtype identification.

Main Results:

• Out of 50 samples, 49 were positive for Campylobacter on all three media.
• The majority of samples (71%) yielded Campylobacter isolates of the same sequence type across all three media.
• In 26% of samples, one medium recovered an isolate with a different sequence type compared to the other two media, with Campy-Cefex and RF Campylobacter jejuni/coli agars showing this tendency more often.

Conclusions:

• In most instances, the three selective plating media effectively detect the same Campylobacter subtypes in complex, naturally contaminated chicken samples.
• While minor differences in subtype recovery exist between media, they generally provide comparable results for Campylobacter surveillance in poultry.
• The study highlights the importance of considering potential media bias when interpreting Campylobacter subtyping data.