Evaluating Methods for Detecting Escherichia albertii in Chicken Meat.

Area of Science:

• Food Microbiology
• Bacteriology
• Food Safety

Background:

• Escherichia albertii is an emerging foodborne pathogen.
• Identifying the source of E. albertii infections is challenging due to difficulties in isolating it from food and water.
• E. albertii has a wide host range, including birds, and is found in chicken meat.

Purpose of the Study:

• To evaluate and optimize PCR assays, enrichment, and isolation conditions for detecting E. albertii in chicken meat.
• To determine the efficacy of different growth media and PCR enzymes for E. albertii detection.
• To establish reliable methods for E. albertii surveillance in food and for outbreak investigations.

Main Methods:

• Evaluated growth of E. albertii strains in modified EC broth (mEC) and novobiocin-supplemented mEC (NmEC).
• Assessed PCR enzyme activity, enrichment conditions, most-probable-number (MPN) method, and selective agar media (DHL, MAC, RX-DHL, RX-MAC).
• Tested PCR sensitivity using inoculated chicken meat samples under optimized conditions.

Main Results:

• All E. albertii strains grew in mEC and NmEC at 36°C and 42°C and did not utilize rhamnose, sucrose, or xylose.
• A sensitive PCR assay detected E. albertii in chicken meat enrichment cultures (>20 CFU/25g) after incubation at 42°C for 22 ± 2 hours.
• Enrichment in NmEC followed by plating on RX-DHL or RX-MAC yielded higher isolation rates (70.1–100%) compared to mEC and standard agars.

Conclusions:

• Optimized enrichment in NmEC and selective plating on RX-DHL/RX-MAC significantly improve E. albertii isolation from chicken meat.
• The developed PCR assay is sensitive enough for detecting E. albertii contamination in chicken meat.
• These optimized conditions are crucial for effective foodborne pathogen surveillance and investigating E. albertii outbreaks.