Temporal efficacy of antimicrobials against aerobic bacteria isolated from equine endometritis: an Italian retrospective analysis (2010–2017)

Abstract

This study aimed to describe bacteria isolated from the reproductive tract of mares and to identify changes in antimicrobial susceptibility patterns to those antibiotics commonly used for the treatment of equine endometritis. A total of 4122 equine uterine swabs were collected from mares suffering from reproductive tract disorders in the period 2010-2017. Aerobic culture and antimicrobial susceptibility testing using agar disc diffusion were performed on each sample. Aerobic bacteria were isolated from 3171 of 4122 (76.9 per cent) samples. The most frequently isolated microorganisms were Escherichia coli (885/3171, 27.9 per cent) and Streptococcus equi subspecies zooepidemicus (791/3171, 24.9 per cent), confirming previous findings from the literature. Antimicrobial susceptibility patterns of E coli, S equi subspecies zooepidemicus and Klebsiella pneumoniae changed over time. A statistically significant decrease in antimicrobial efficacy of cefquinome against E coli was observed over the years, as well as of ampicillin, cefquinome and penicillin against S equi subspecies zooepidemicus. The high frequency of resistant bacteria isolated in the present work proceeds in the same way as indicated by surveillance data on the huge antibiotic use in Italy. As a result, testing and monitoring programmes of antimicrobial efficacy are crucial to consciously using antibiotics and preserving their effectiveness both for veterinary and human medicine.

Antimicrobial resistance in bacteria isolated from the uteri of horses with endometritis

“…Pissello and colleagues suggest that indiscriminate use of these antimicrobials within this region may explain their indings. 7 This further highlights the need for prudent use of antimicrobial agents in equine practice and the use of culture and susceptibility testing instead of empirical treatment selection.…”

“…Of particular concern is the high level of resistance to the broad‐spectrum cephalosporins observed in E coli isolates, given that these drugs are considered as critically important with respect to human medicine and the alternative therapeutic options in the case of resistance are limited. Pissello and colleagues suggest that indiscriminate use of these antimicrobials within this region may explain their findings 7 . This further highlights the need for prudent use of antimicrobial agents in equine practice and the use of culture and susceptibility testing instead of empirical treatment selection.…”

“…1,[4][5][6] In a study summarised on p 598 of this issue of Vet Record, Pisello and colleagues examined the aerobic bacteria isolated from the uteri of Italian mares with clinical signs of endometritis and the temporal changes in their antimicrobial susceptibility patterns over an eight-year period. 7 Escherichia coli and Streptococcus equi subspecies Zooepidemicus were the most commonly isolated bacteria from the cases of endometritis included in the study by Pisello and colleagues. This is consistent with previously published reports from other parts of the world.…”

“…While our understanding of AMR dynamics in equine populations is relatively limited, an increasing number of reports on the AMR patterns and temporal trends in bacteria isolated from clinical cases in horses have been published 1,4–6 . In a study summarised on p 598 of this issue of Vet Record , Pisello and colleagues examined the aerobic bacteria isolated from the uteri of Italian mares with clinical signs of endometritis and the temporal changes in their antimicrobial susceptibility patterns over an eight‐year period 7 …”

Antimicrobial Resistance in Equine Reproduction

“…Italy [44] Isolates from uterine swabs of mares suffering from endometritis. E. coli was highly resistant to ampicillin, cefquinome, cefazolin, ceftiofur, penicillin, rifampin, and thiamphenicol.…”