Implications of multiple antimicrobial-resistant enterococci associated with the poultry environment

Area of Science:

• Veterinary Microbiology
• Antimicrobial Resistance
• Food Safety

Background:

• Poultry are increasingly linked to multiresistant organisms, posing potential human health risks.
• Enterococci, though not common causes of hospital infections, can become clinically significant when resistant.
• Antimicrobial use in poultry may drive resistance in Enterococcus species.

Purpose of the Study:

• To determine the prevalence and resistance patterns of multiresistant enterococci in Delmarva region poultry environments.
• To identify predominant Enterococcus species and their antimicrobial resistance profiles.

Main Methods:

• Litter and transport container swabs from commercial poultry houses were cultured for Enterococcus species.
• Biochemical screening using a microtiter plate adaptation identified predominant species.
• Antimicrobial resistance profiling was conducted for various antibiotic classes.

Main Results:

• Enterococcus faecalis (61.2%), Enterococcus faecium (18.6%), and Enterococcus gallinarum (2.4%) were predominant species.
• Uniform resistance to cephalosporins, macrolides, and tetracyclines was observed.
• High-level streptomycin resistance was found in ~30% of isolates, particularly E. faecalis.
• Significant resistance to quinupristin-dalfopristin (70.4%) was noted in E. faecium.

Conclusions:

• Poultry environments in the Delmarva region harbor multiresistant enterococci.
• Resistance patterns indicate potential for clinical significance and public health concerns.
• Further investigation into antimicrobial use and resistance mechanisms is warranted.