Evolution of In Vitro Antimicrobial Susceptibility of Equine Clinical Isolates in France between 2016 and 2019

Abstract

The present study described the evolution of antimicrobial resistance in equine pathogens isolated from 2016 to 2019. A collection of 7806 bacterial isolates were analysed for their in vitro antimicrobial susceptibility using the disk diffusion method. The most frequently isolated pathogens were group C Streptococci (27.0%), Escherichia coli (18.0%), Staphylococcus aureus (6.2%), Pseudomonas aeruginosa (3.4%), Klebsiella pneumoniae (2.3%) and Enterobacter spp. (2.1%). The majority of these pathogens were isolated from the genital tract (45.1%, n = 3522). With the implementation of two French national plans (named ECOANTIBIO 1 and 2) in 2012–2016 and 2017–2021, respectively, and a reduction in animal exposure to veterinary antibiotics, our study showed decreases in the resistance of group C Streptococci, Klebsiella pneumoniae and Escherichia coli against five classes, four classes and one class of antimicrobials tested, respectively. However, Staphylococcus aureus, Escherichia coli and Enterobacter spp. presented an increased resistance against all the tested classes, excepted for two fifths of E. coli. Moreover, the percentages of multi-drug resistant strains of Staphylococcus aureus and Enterobacter spp. also increased from 24.5% to 37.4% and from 26.3% to 51.7%, respectively. The data reported here are relevant to equine practitioners and will help to improve knowledge related to antimicrobial resistance in common equine pathogens.

Metagenomic Analysis of Fecal Archaea, Bacteria, Eukaryota, and Virus in Przewalski's Horses Following Anthelmintic Treatment

“…Infection of Streptococcus pneumoniae will trigger immune response of the horse to accumulate leucocytes and cytokine ( 81 ). Pseudomonas aeruginosa is an opportunistic pathogen that is commonly recognized as a cause of endometritis in horses ( 82 , 83 ). Escherichia coli are common commensal bacteria found in the intestinal tract of horses; they can cause diarrhea ( 83 , 84 ).…”

“…Pseudomonas aeruginosa is an opportunistic pathogen that is commonly recognized as a cause of endometritis in horses ( 82 , 83 ). Escherichia coli are common commensal bacteria found in the intestinal tract of horses; they can cause diarrhea ( 83 , 84 ). Casual usage of anthelmintic treatment poses a risk to the horses, known as colic ( 26 ).…”

The Animal-foods-environment interface of Klebsiella pneumoniae in Germany: an observational study on pathogenicity, resistance development and the current situation

“…Klebsiella pneumoniae was extensively investigated in humans, but very few studies have been carried out on animals and foods. Between 2013 and 2014, PMQR-containing K. pneumoniae strains were isolated from dogs in Belgium, Spain, Poland, the Czech Republic [39], and K. pneumoniae was representing 2.3% of 7,806 bacterial isolates recovered from diseased equines in France between 2016 and 2019 [71]. Strains harbouring blaCTX-M-1, blaOXA-1, qnrB, aac (6), aac(6)-Ib, catB3, blaSHV, qrnB, qnrS, aphA, sul1 and dfrA12 were isolated from dogs in Austria [72].…”

Equine antimicrobial therapy: Current and past issues facing practitioners

“…Pseudomonas is generally considered an opportunistic pathogen, which is frequently multidrug resistant. It can cause a variety of infections in horses, including skin, reproductive tract, and respiratory diseases (Leon et al, 2020). Interpretation of cultures should be made in light of the clinical picture, as well as the purity and magnitude of growth on culture, because Pseudomonas can frequently be cultured as a contaminant.…”