Animal manure is applied in agriculture to improve soil fertility and crop yield. Nonetheless, manure can also carry Escherichia coli (E. coli), including antibiotic-resistant strains. Therefore, it may pose a risk for environmental contamination. This review includes 50 studies which were identified from the search terms related to the transmission of E. coli through manure. The review outlines the potential routes of E. coli transmission from manure to soil, water and crops and which factors most critically determine persistence and contamination. The persistence of E. coli in soil is highly variable, ranging from <30 days for composted manures to more than 200 days in cooler conditions. These differences depend on the type of manure used, the environmental conditions and the treatment employed. While crops can be contaminated directly through application of manure, contaminated irrigation water may be a more important pathway. The foremost cause of surface water contamination seems to be rainfall runoff, whereas groundwater contamination is rather uncommon, mainly happening in areas with specific soil conditions. Composting and adherence to pre-harvest intervals are very effective mitigation strategies that can greatly reduce contamination risks. Overall, this review identifies research gaps on water contamination pathways and the persistence of resistant strains. Moreover, it sets up the basis for the development of robust risk assessments and evidence-informed approaches to address the contamination risks that are linked to animal manure.
Background/Objectives: Antimicrobial resistance (AMR) threatens global public health. This systematic review and meta-analysis, as part of the “ENVIRE” project (interventions to control the dynamics of antimicrobial resistance from chickens through the environment), assesses the prevalence of phenotypic and genotypic resistance, including extended-spectrum beta-lactamases (ESBLs), AmpC beta-lactamases, carbapenemases, colistin, and fluoroquinolone resistance, in broiler chickens and their environment. Methods: The analysis covers the years 2002–2022, focusing on Escherichia (E.) coli, Klebsiella spp., Enterobacter spp., and Citrobacter spp. in fecal, meat, environmental, and other-than-feces samples from observational studies published in PubMed and Web of Science. Quality assessment was performed using the Alberta Heritage Foundation criteria. Results: Data from 170 studies, conducted in Europe, North Africa, and North America, were included. The most frequently studied resistance was to beta-lactam, with focus on ESBL-producing and AmpC beta-lactamase isolates. The pooled prevalence of ESBL-resistant E. coli observed in meat samples at 41% and in fecal samples at 38% demonstrated significant heterogeneity between the studies. The negative binomial regression analysis of prevalence data revealed significantly higher ESBL-producing E. coli rates in European meat samples compared to North African samples. Conclusions: This systematic review revealed substantial variation in prevalence and emphasizes the need for standardized surveillance systems and robust study designs.
Background/Objectives: While antibiotic usage in farm animals has been systematically monitored and reduced in many countries, including Germany, data on companion animals such as dogs and cats remain scarce. To address this gap, a study was conducted in Germany to analyze patterns of antibiotic use in dogs and cats. Methods: Antibiotic usage data were obtained from debevet, a cloud-based veterinary practice management software based in Berlin, Germany. Practices with fewer than 100 patients were excluded, and data from 2018 to 2022 were analyzed. Results: The analysis included 477,310 consultations of 78,381 dogs and 241,532 consultations of 55,729 cats across 133 veterinary practices. Antibiotics were used in 12.9% of dog consultations and 22.5% of cat consultations, with substantial variation across practices. Aminopenicillins, particularly amoxicillin, were the most commonly used antibiotics, while the highest-priority critically important antibiotics (HPCIAs) accounted for 12.4% of treatments. Follow-up treatments led to changes in antibiotic substances in 9.3% of cases, often within the first two days. Indications varied by species, with respiratory issues more frequent in cats and orthopedic problems in dogs. Body weight and breed characteristics influenced the likelihood of antibiotic treatment, with short-nosed breeds showing higher odds. Conclusions: The routine data analysis provided valuable insights into antibiotic use in dogs and cats, enabling tracking trends across species and indications over time. While some specific information was missing, the invoicing data’s completeness, the cost-effectiveness of their use, and their unbiased nature make them a robust tool for monitoring and informing legislative changes.
Extended-spectrum beta-lactamase (ESBL)-producing E. coli from broiler farms can reach watersheds used for recreational swimming. We assessed short-term swimmer exposure by extending a modular quantitative microbial risk assessment (QMRA) to the recreational water pathway linking land manure application to in-stream fate and transport with dilution and decay. We modeled single-event exposure doses and estimated loss of disability-adjusted life years (DALYs). We ran sensitivity analyses on several parameters and compared outputs to published recreational water assessments that include ESBL E. coli. Assuming a worst-case scenario, single-event doses were lower for adults (2.95 CFU; UI 0.14–6.11) and higher for children (8.78 CFU; UI 0.56–17.20) on day 1 after land application, then dropped below 0.01 CFU by day 200, with DALY losses from 10−7 to 10−10. Uncertainty was dominated by fate and transport. Stronger particle binding, faster in-stream decay, and larger effective volumes lowered exposure, while higher shedding, greater flow, and larger wash-off raised it. Estimates fell at the low end of prior studies. Swimmer exposure appears to be extremely low and short-lived. The modular QMRA links farm contamination to bathing-site risk and supports risk-based monitoring (after spreading or storms) and short-term forecasts that focus advisories on short, higher-risk windows after litter application.
Background: Extended-spectrum β-lactamase-producing Escherichia coli (ESBL E. coli ) from broiler chicken production pose potential public health risks via multiple environmental and foodborne pathways. We developed a modular quantitative microbial risk assessment (QMRA) model linking four components, namely farm, soil, river, and lettuce consumption, to predict human environmental exposure to ESBL E. coli originating from broiler flocks. Methods: A stochastic farm module simulated broiler colonization over a 36-day cycle and generated end-cycle litter loads. Field modules represented first-order decay, attachment/partitioning, and runoff to rivers; irrigation transfer yielded lettuce contamination for a 100 g serving. Disability-Adjusted Life Year (DALY) estimation characterized health risk and global sensitivity analyses identified main drivers. Results: The farm model produced mean end-cycle litter of 1.6 × 10 4 (SD 16.1, UI 1.60–1.61 × 10 4 ) CFU/g and near-complete flock colonization within one week. Soil surface loads declined from 3.2 × 10 7 (SD 3.2 × 10 4 , UI 3.2–3.2 × 10 7 ) CFU/m 2 to 8.6 × 10 5 (SD 8.8 × 10 2 , UI 8.6–8.6 × 10 5 ) CFU/m 2 by day 100. Runoff yielded river concentrations of 6.0 × 10 -2 (SD 3.5 × 10 -3 , UI 5.5–6.6 × 10 -2 ) CFU/mL after ten days. Lettuce contamination was highest at short intervals after land application 1.7 (SD 8.5 × 10 -2 , UI 1.5–1.8) CFU/100 g at one day interval, dropping to 0.85 (SD 5.0 × 10 -2 , UI 0.76–0.95) CFU/100 g at day 20 interval; simple household washing cut exposure by ∼90 %. Global sensitivity analysis identified soil-water partitioning and decay rates as most important parameters of exposure variability. DALYs lost ranged from 10 -8 to 10 -10 per serving. Conclusions: In our scenarios, predicted health burdens varied with ESBL E. coli concentration in irrigation water and intervals between litter application and lettuce planting. While environmental decay and simple measures such as household washing substantially reduce exposure, residual contamination persists. Future studies should evaluate the effectiveness of manure treatments and irrigation-water quality interventions on reducing environmental loads and human risk.
Background/Objectives: A mandatory monitoring of the use of antibiotics in horses in the European Union will come into force from 2027 on. The aim of the study was to explore the potential implementation of a monitoring system and to provide an overview of antibiotic use in horses in Germany. Methods: Data on all consultations from 57 German practices between 2018 and 2023 were obtained. The dataset included basic data about the horse, free-text diagnoses (allocated to one of 20 categories), and treatments. Information on the administered or dispensed pharmaceutical product was recorded for antibiotic treatment consultations. Results: This study analyzed 225,622 consultations with more than 50,000 horses. Antibiotics were administered in around 7% of consultations, but practice-specific rates varied considerably. Treatment was most frequent in ophthalmology cases. The most commonly used drug classes were sulfonamides combined with trimethoprim and aminopenicillins. Horses receiving antibiotics required follow-up visits more often than untreated animals, and changes in antibiotic substance occurred occasionally. Conclusions: Routine practice data provide valuable insights into antibiotic use in equine medicine. While incomplete entries and imprecise details (e.g., missing concentrations or diagnoses) remain a limitation, the approach offers clear advantages: it is cost-effective, allows large-scale data collection, and supports continuous monitoring over time. Such systems can be used to evaluate the effects of upcoming EU regulations and to identify priorities for antibiotic stewardship in equine practice.