Evaluation of Antibiotic Dissemination into the Environment and Untreated Animals, by Analysis of Oxytetracycline in Poultry Droppings and Litter

Abstract

Oxytetracycline (OTC) is widely used in broiler chickens. During and after treatment a fraction of OTC is excreted in its original form and as its epimer, 4-epi-OTC in droppings. To address the transfer of OTC into the environment, we evaluated the dissemination of OTC and 4-epi-OTC from treated birds to the environment and sentinels, through the simultaneous analysis of broiler droppings and litter. Male broiler chickens were bred in controlled conditions. One group was treated by orogastric tube with 80 mg kg−1 of OTC and two groups received no treatment (sentinels). OTC+4-epi-OTC were analyzed and detected by a HPLC-MS/MS post the end of treatment. The highest concentrations of OTC+4-epi-OTC were detected in the droppings of treated birds 14-days following the end of treatment (2244.66 µg kg−1), and one day following the end of treatment in the litter (22,741.68 µg kg−1). Traces of OTC+4-epi-OTC were detected in the sentinels’ droppings and litter (<12.2 µg kg−1). OTC+4-epi-OTC can be transferred from treated birds to the environment and to other untreated birds. The presence and persistence of OTC+4-epi-OTC in litter could contribute to the selection of resistant bacteria in the environment, increasing the potential hazard to public and animal health.

Assessing the Effect of Oxytetracycline on the Selection of Resistant Escherichia coli in Treated and Untreated Broiler Chickens

“…Although it was not possible to statistically correlate the concentrations with the selection of resistant bacteria, a higher prevalence of non-susceptible E. coli was determined in the first sampling point, where the concentrations in both matrices were significantly higher than in the subsequent sampling. Therefore, it is inferred that the isolated E. coli population in the first point underwent a higher selection pressure by the excreted antimicrobial, where the concentrations of OTC and its epimer detected were 22,742 µg kg −1 in litter and 2,087 µg kg −1 in droppings of treated animals [20].…”

Depletion and Distribution Studies for Oxytetracycline in Broiler Chicken using Commercial ELISA with Subsequent Confirmatory Analysis by HPLC-UV

“…The long half-life of OTC and the use of broiler droppings to fertilize soil also present a risk for the transfer and persistence of OTC. It is a threat to the food cycle that excretion of Oxytetracycline bind to soil (Carballo et al 2016;Pokrant et al 2021).…”

Significance and Challenges of Poultry Litter and Cattle Manure as Sustainable Fuels: A Review

“…Moreover, animal waste contains pathogens such as Enterobacteriaceae, Salmonella, and Pseudomonas, molds, and fungal species [7], which, when spread on the land, are a possible danger to human and animal health [8]. It is common to add antibiotics to animal feed and drinking water, such as oxytetracycline (OTC), which is poorly absorbed in the gastrointestinal tract of animals, making feces a potential path of dissemination [9]. This may cause not only the presence of antibiotics in the soil and groundwater, but also the development of resistant bacteria and affect the normal microbial processes in the soil.…”