European-wide antimicrobial resistance monitoring in commensal Escherichia coli isolated from healthy food animals between 2004 and 2018

Abstract

Objectives To describe the susceptibility of Escherichia coli to medically important antibiotics, collected over four periods (2004–2006, 2008–2009, 2013–2014, 2017–2018), from food-producing animals at slaughter. Methods Intestinal contents from cattle, pigs and broilers were randomly sampled (5–6 countries/host; ≥4 abattoirs/country; one sample/animal/farm) for isolation of Escherichia coli; antimicrobial susceptibilities were centrally determined by CLSI agar dilution. Clinical breakpoints (CLSI) and epidemiological cut-off values (EUCAST) were applied for data interpretation. Results In total, 10 613 E. coli strains were recovered. In broilers, resistance percentages were the lowest (P ≤ 0.01) in the latest time period. A significant decrease in MDR over time was also observed for broilers and a tendency for a decrease for pigs. Resistance to meropenem and tigecycline was absent, and resistance to azithromycin was 0.2%–2.0%. Also, low resistance to third-generation cephalosporins (1.1%–7.4%) was detected in broilers. Resistance to colistin varied between 0.1%–4.8%. E. coli from broilers showed high resistance to ciprofloxacin (7.3%–23.3%), whereas for cattle and pigs this was 0.2%–2.5%. Low/moderate resistance to chloramphenicol (9.3%–21.3%) and gentamicin (0.9%–7.0%) was observed in pigs and broilers. The highest resistance was noted for ampicillin (32.7%–65.3%), tetracycline (41.3%–67.5%), trimethoprim (32.0%–35.7%) and trimethoprim/sulfamethoxazole (27.5%–49.7%) from pigs and broilers, with marked country differences. MDR peaked in pigs and broilers with 24 and 26 phenotypes, with 21.9%–26.2% and 18.7%–34.1% resistance, respectively. Conclusions In this pan-EU survey antibiotic susceptibility of commensal E. coli varied largely between antibiotics, animal species and countries. Resistance to critically important antibiotics for human medicine was absent or low, except for ciprofloxacin in broilers and ampicillin in pigs and broilers.

Evaluating Antimicrobial Resistance Trends in Commensal Escherichia coli Isolated from Cecal Samples of Swine at Slaughter in the United States, 2013–2019

“…Another important finding of this study was the high resistance levels to ampicillin and streptomycin. Similar observations have been reported in long-term antimicrobial resistance monitoring programs conducted in the US [35] and globally [40]. In our study, the prevalence of resistance to streptomycin did not show a temporal trend.…”

“…Multidrug resistance was detected in 14.9% of the swine E. coli isolates in the present study, which was lower than what was reported for pigs (53.7%) in the previous nationwide surveillance between 1950 and 2002 in the US [35] as well as in the European-wide investigation between 2004 and 2018 (23.7%) [40]. In addition to geographical factors and differences in laboratory and analytical methods used for detecting AMR, the MDR rates and AMR patterns of enteric bacteria in food animals can also be influenced by the antimicrobial use policies and interventions employed in different regions [55].…”

“…The results of our study align with a previous investigation conducted in India, which reported a 1.6-fold increase in MDR E. coli isolates derived from food animals between 1980 and 2018 [65]. Contrasting results were also reported in a prior European investigation, wherein a tendency towards a reduction in MDR E. coli strains over time was observed in pigs [40].…”

“…Additionally, genes responsible for resistance to these compounds are frequently associated with mobile genetic elements, leading to co-resistance [58,59]. Another plausible explanation for the observed trends of increasing resistance in the absence of certain antimicrobial use is that the selection of resistance by a particular compound can potentially result in resistance to other molecules within the same class [40].…”

Antimicrobial Resistant Coagulase-Negative Staphylococci Carried by House Flies (Musca domestica) Captured in Swine and Poultry Farms

“…However, in this study, small-medium size farms were analyzed, and we could hypothesize a stronger use of antimicrobials in poultry flocks. In addition, results of other works seem to suggest a more abundant use of antimicrobials in poultry farms, reporting higher detection of antimicrobial-resistant bacteria or antimicrobial-resistance genes [ 38 , 39 , 40 ].…”