Genetic characterization of Arcobacter isolates from various sources

Area of Science:

• Food safety and microbiology
• Veterinary public health
• Bacterial genomics and epidemiology

Background:

• Arcobacter species are increasingly recognized as foodborne pathogens, detected in diverse animal hosts and food products.
• Understanding Arcobacter prevalence and transmission at the farm level is crucial for preventing human infections.

Purpose of the Study:

• To determine the prevalence of Arcobacter species in dairy cattle, associated farm environments, and retail beef in Malaysia.
• To analyze the genetic relatedness of Arcobacter isolates from these sources.

Main Methods:

• Sample collection from dairy cattle (cattle, floor, water, milk) and retail beef.
• Bacteriological isolation and identification of Arcobacter species.
• Molecular typing using pulsed-field gel electrophoresis (PFGE) after Eag1 digestion.

Main Results:

• Overall Arcobacter prevalence was 15% (63/421) across all sources.
• Higher detection rates were observed in floor (26.7%), beef (26.3%), and water (11.1%).
• Arcobacter butzleri was the most frequent species; multiple species co-occurred in 75% of floor samples and 53.8% of beef samples.
• PFGE analysis revealed 12 major clusters with 29 distinct band patterns, indicating genetic diversity and potential cross-contamination.

Conclusions:

• Arcobacter contamination is prevalent in Malaysian dairy farms and beef supply chains.
• The presence of multiple Arcobacter species and closely related strains in beef suggests cross-contamination.
• Fecal shedding by animals can contaminate water and milk, posing a risk to human health.