Multiresistant Bacteria Isolated from Intestinal Faeces of Farm Animals in Austria

Area of Science:

• Veterinary Microbiology
• Food Safety
• Antimicrobial Resistance

Background:

• Antibiotic-resistant bacteria (ARB) in food pose a significant human health risk.
• Antibiotic use in animal husbandry drives the emergence and spread of ARB.
• Food products can act as a reservoir for ARB, necessitating broader investigation.

Purpose of the Study:

• To investigate the prevalence of specific ARB, including extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococci (VRE), in swine and broiler intestines.
• To identify and characterize resistance genes in isolated bacteria.
• To assess the intestine as a primary habitat for multiresistant bacteria.

Main Methods:

• Faeces samples were collected directly from the intestines of swine (n=71) and broilers (n=100) during slaughter.
• Samples were analyzed for ESBL-producing Enterobacteriaceae, MRSA, Methicillin-resistant Coagulase-Negative Staphylococci (MRCoNS), and VRE.
• Resistance genes were detected and sequenced using Polymerase Chain Reaction (PCR).

Main Results:

• Phenotypic ESBL-producing Escherichia coli were found in 10% of broiler intestines and 43.6% of swine intestines.
• CTX-M-1 was the dominant ESBL in swine E. coli (83.3%), while SHV-12 was dominant in broiler E. coli (81.3%).
• The overall frequency of multidrug-resistant bacteria in intestinal samples was lower than reported in many studies focusing on meat products.

Conclusions:

• The swine and broiler intestinal tract harbors significant levels of ESBL-producing E. coli.
• Intestinal screening provides valuable data on ARB reservoirs in food-producing animals.
• Findings suggest that while meat products may have lower contamination rates, animal intestines are a critical monitoring point for ARB surveillance.