Prevalence of Virulence Genes and Antimicrobial Resistances in E. coli Associated with Neonatal Diarrhea, Postweaning Diarrhea, and Edema Disease in Pigs from Austria.

René Renzhammer,Beate Pinior,Joachim Spergser,Igor Loncaric,Annemarie Käsbohrer,Franz-Ferdinand Roch,Andrea Ladinig,Christine Unterweger

doi:10.3390/antibiotics9040208

René Renzhammer, Beate Pinior + Show 6 more

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https://doi.org/10.3390/antibiotics9040208

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Abstract

Increasing numbers of multi-resistant Escherichia (E.) coli from clinical specimens emphasize the importance of monitoring of their resistance profiles for proper treatment. Furthermore, knowledge on the presence of virulence associated genes in E. coli isolates from European swine stocks is scarce. Consequently, a total of 694 E. coli isolated between 2016 and 2018 from diarrheic piglets of Austrian swine herds were investigated. The isolates were tested for their susceptibility to twelve antibiotics using agar disk diffusion test and for the presence of 22 virulence associated genes via PCR. Overall, 71.9, 67.7, and 49.5% of all isolates were resistant to ampicillin, tetracycline, and trimethoprim-sulfamethoxazole, while resistance levels to gentamicin and fosfomycin were 7.7 and 2.0%, respectively. Resistance frequency to ciprofloxacin was higher than in previous studies. Isolates were more likely to be resistant to ampicillin if they were also resistant to ciprofloxacin. No isolate was resistant to meropenem or amikacin. Virulence genes were detected more frequently in isolates expressing hemolytic activity on blood agar plates. The detection rate of faeG was increased in fimH negative isolates. We assume, that hemolytic activity and absence of fimH could be considered as potential indicators for the virulence of E. coli in piglets.

Highlights

The emergence of multi-resistant bacteria is commonly considered to be a consequence of the misuse and overuse of antibiotics [1,2]
Isolates that were resistant to ciprofloxacin were more likely to be resistant to ampicillin (OR = 5.381) and trimethoprim-sulfamethoxazole (OR = 3.482)
Between 2016 and 2018, 694 E. coli strains were isolated from feces and intestines derived from clinically diseased suckling and early weaned piglets from Austrian swine stocks in the course of routine diagnostics performed at the Institute for Microbiology, University of Veterinary Medicine Vienna (Table S1)

Summary

Introduction

The emergence of multi-resistant bacteria is commonly considered to be a consequence of the misuse and overuse of antibiotics [1,2]. A study demonstrated that distinct numbers of pathogenic porcine E. coli were resistant to antibiotics that are commonly applied in swine stocks, such as tetracyclines and trimethoprim/sulfonamide [4]. An increasing number of E. coli isolates resistant to cephalosporins and fluoroquinolones has been reported repeatedly [5,6]. Pathogenic E. coli are one of the main causative agents of diarrhea in swine. They are known to cause neonatal diarrhea, as well as post-weaning diarrhea (PWD) and edema disease (ED), leading to severe economic consequences in pig stocks due to increased mortality rates and decreased growth rates [8]

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