RAISING TECHNOLOGY INDUCED SPATIAL DYNAMICS OF ANTIMICROBIAL RESISTANCE AND ZOONOTIC RISK IN E. COLI ISOLATED FROM SWINE

Abstract

INTRODUCTION Swine are amongst the most important large-scale farmed meat animals, by which a partial coverage of the growing global food demand is managed. Moreover, low-input and organic swine farming continuously expand, proven its beneficial effect on animal welfare and meat quality. In both systems, swine represent a source of E. coli for people by direct contact and food products, the bacteria pathogenicity increasing with its antimicrobial resistance. AIM The study aimed at comparing the dynamics of antibiotic resistance of E. coli strains from pigs raised under intensive and extensive technologies, presuming that under extended antibiotic use on the industrial farm, the number of resistant strains will be higher, than on low-input homesteads located 5 and 10 km from this posing an increased risk for humans. MATERIAL AND METHODS The samples collected from healthy pigs on the industrial farm (n = 16) and the two homesteads (n = 12) were subjected to standard microbiological techniques (cultivation, identification by Vitek 2 system, Kirby-Bauer diffusion test against enrofloxacine, amoxycillin-clavulanic acid, methicillin, cloramphenicol, neomycine, oxytetracycline, cefquinome, tulathromycine, colistine) and MAR (multiple antibiotic resistance) index was calculated. E. coli represented 72% of identified bacteria. MAR index was the lowest on the intensive farm (0.56±0.14) and increased statistically non-significantly with distance (0.59±16, 5 km and 0.61±0.28, 10 km, respectively). CONCLUSION The results undermined the initial hypothesis, probably due to a more controlled use of antibiotics and increased awareness of personnel on the farm, versus uncontrolled human use of antibiotics and internal consumption of obtained meat in the homesteads. Thus, stricter antibiotic residue control and biosecurity measures are needed on small sized households along with rational antibiotic use on the industrial farm to lower the MAR index and implicitly the zoonotic risk posed by E. coli. The work was supported by grant ERANET Core Organic Co-fund ROAM Free #249 ⁄ 2021, European Union’s Horizon 2020 research and innovation programme PPILOW project under grant agreement N°816172