Development and validation of a highly effective analytical method for the evaluation of the exposure of migratory birds to antibiotics and their metabolites by faeces analysis

Abstract

The widespread occurrence of antibiotics in the environment may exert a negative impact on wild organisms. In addition, they can become environmental reservoirs, through the ingestion of food or contaminated water, and vectors for antibiotic-resistant bacteria. This fact is even more important in migratory birds that can promote their dissemination across continents. In this work, a multiresidue analytical method suitable for the determination of five families of antibiotics and their main metabolites in waterbird faeces has been developed and validated. The target compounds include environmentally significant sulfonamides, macrolides, fluoroquinolones, tetracyclines and antifolates. Sample treatment involves ultrasound-assisted extraction with methanol and dispersive solid-phase extraction clean-up with C18. Analytical determination was carried out by liquid chromatography–tandem mass spectrometry. The most significant parameters affecting sample extraction and extract clean-up were optimised by means of experimental designs. Good linearity (R2 > 0.994), accuracy (from 41 to 127%), precision (relative standard deviation lower than 24%) and limits of quantification (lower than 2 ng g−1 (dry weight, dw)) were obtained for most of the compounds. The method was applied to the determination of the selected compounds in 27 faeces samples from three common migratory waterbird species. Nine antibiotics and three of their metabolites were detected in the analysed samples. Fluoroquinolones and macrolides were the antibiotics most frequently detected. The highest concentrations corresponded to norfloxacin (up to 199 ng g−1 dw). Graphical abstract

Thermodynamic and Kinetic Investigation of the Adsorption and Desorption of Trimethoprim and Its Main Metabolites in Mediterranean Crop Soils

“…The selected soils’ physicochemical characteristics are presented in Table 3 . The previous presence of TMP and its metabolites in the studied soils was evaluated by the analysis of the selected soils, as reported by Mejías et al (2022) [ 37 ]. In all cases, concentrations of TMP, DM-TMP, and OH-TMP were lower than the method’s detection limits.…”

Domestic Waste and Wastewaters as Potential Sources of Pharmaceuticals in Nestling White Storks (Ciconia ciconia)

“…Due to the relatively short half-lives of acetaminophen (0.45–4 h, [ 86 ]) and marbofloxacin (1.6–15 h, [ 87 , 88 ]) depending on livestock species, the use of other types of samples such as faeces or feathers may also be useful to assess exposure in wild birds. Indeed, antibiotics (including enrofloxacin and ciprofloxacin) and their metabolites were detected at high frequency in the faeces of white storks and two gull species wintering in Doñana National Park and surrounding areas in Andalusia, South Spain [ 53 ]. In addition, recently, human and veterinary pharmaceuticals (NSAIDs and antidepressants) were detected in the feathers of fledging Mediterranean gulls ( Ichtyaetus melanocephalus ) and Sandwich terns ( Thalasseus sandvicensis ) from the Venice Lagoon (Italy), with diclofenac being the most commonly detected drug [ 40 ].…”

“…It has been argued that the high frequency of antibiotic-resistant bacteria in this species is due to passive acquisition in landfills and through contaminated water [ 51 , 52 ] rather than direct exposure to these drugs via ingestion. This contrasts with evidence of residues of parent antibiotics and their metabolites in faeces of this species, which is attributed to foraging in landfills and bioaccumulation in their aquatic prey [ 53 ]. To our knowledge, there is no information on the presence of pharmaceuticals as circulating pollutants in this species.…”

Multiresidue method for the determination of critically and highly important classes of antibiotics and their metabolites in agricultural soils and sewage sludge

“…Injection volume was 10 µL. Chromatographic conditions were those previously optimised and reported [ 31 ]. Briefly, MS/MS parameters were optimised in both positive and negative modes by direct infusion of 1 µg mL −1 individual and mixture solutions of the target compounds.…”