Antibiotic Resistance Profiles of Escherichia coli Recovered from Mesenteric Lymph Nodes of Free-Ranging Game Ungulates in Western Romania.

Background/

Objectives

The emergence of antimicrobial resistance (AMR) within a One Health framework highlights the role of wildlife as environmental reservoirs. Because wild game is an increasingly important meat source, hygienic handling during evisceration is critical to prevent carcass contamination from internal tissues such as mesenteric lymph nodes (MLNs). This study aimed to investigate the occurrence and antibiotic resistance (AR) profiles of Escherichia coli isolated from the MLNs of hunted wild ungulates in western Romania to better understand microbiological hazards along the game meat supply chain.

Methods

MLN samples were aseptically collected from 103 legally hunted wild boars (Sus scrofa, n = 78) and cervids (Capreolus capreolus and Cervus elaphus, n = 25) across two hunting grounds. E. coli isolation was performed utilizing selective Tryptone Bile X-Glucuronide agar. Subsequent biochemical identification and phenotypic antimicrobial susceptibility testing were conducted using the automated VITEK® 2 system.

Results

The overall E. coli isolation rate was 72.8% (75/103). Analyzed by host species, the bacterium was recovered from 79.4% of the sampled wild boars (62/78) and 52.0% of the cervids (13/25). Phenotypic resistance to at least one antibiotic agent was observed in 25.3% (19/75) of the isolates, most frequently against cephalosporins (cefalexin, 21.3%) and penicillins (ampicillin, 24.0%). Multidrug resistance (MDR) was identified in 20.0% (15/75) of the isolates.

Conclusions

The detection of MDR E. coli phenotypes within the MLNs of free-ranging game indicates the penetration of clinically relevant resistance mechanisms into sylvatic environments. These findings underscore the potential risk of internal carcass contamination during field evisceration, highlighting the critical need for strict hygiene practices to ensure game meat safety.