Urban Birds as Antimicrobial Resistance Sentinels: White Storks Showed Higher Multidrug-Resistant Escherichia coli Levels Than Seagulls in Central Spain

Antimicrobial resistance (AMR) has become a major health challenge of the 21st century. Several studies confirm the potential role of wildlife as sentinel for pathogens surveillance. Moreover, the presence of AMR bacteria in the wildlife can be considered as a good indicator of anthropization level on the ecosystem. The fast increase in AMR worldwide has been enhanced by several factors as globalization and migration. The study of antimicrobial resistance in wild birds is of great importance, as they can travel hundreds of kilometers and disseminate pathogens and AMR across different regions or even continents. The aim of this study was to compare the level of AMR in three bird species: white stork (Ciconia ciconia), lesser black-backed gull (Larus fuscus) and black-headed gull (Chroicocephalus ridibundus). For the analysis, 17 antibiotics from the most representative classes were tested by disk-diffusion method. Results showed 63.2% of seagulls and 31.6% of white storks as carriers of antimicrobial-resistant Escherichia coli, and from all of them, 38.9% were considered multi-drug resistant. Betalactamics, quinolones and tetracyclines were the antibiotic classes with the highest rate of AMR.Ministry of Ecological Transition (MITECO) of SpainComplutense University of Madrid (Spain)3.231 JCR (2021) Q1, 13/62 Agriculture, Dairy & Animal Science0.610 SJR (2021) Q1, 96/456 Animal Science and ZoologyNo data IDR 202

First diclofenac intoxication in a wild avian scavenger in Europe

Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) with a well-known toxicity for old world vultures that ingest the carrion of domestic animals treated with it. Diclofenac intoxication was directly related to the dramatic declines in the populations of three native South Asian Gyps vulture species two decades ago. In 2013, this NSAID was authorised for veterinary use in Spain, which has the largest vulture populations in Europe. One of these species is the cinereous vulture (Aegypius monachus), which is classified as “near threatened” by the International Union for Conservation of Nature (IUCN). This species has been reintroduced and monitored in Catalonia (NE Spain) since 2007, and in 2020 its current population consisted of 15 breeding pairs and a total number of 61 individuals. In September 2020, one fledgling was found dead in the nest. Post-mortem examination revealed severe generalised visceral and articular gout, which was confirmed histologically. Diclofenac was detected at average concentrations of 26.5 ng/g in the liver and 51.4 ng/g in kidney replicates (n = 3), respectively. These findings support a diagnosis of fatal gout caused by diclofenac intoxication. This is the first case of diclofenac poisoning in Spain (and in Europe), in addition to being the first report of diclofenac poisoning in cinereous vultures. This case report, therefore, supports the need to closely monitor vulture populations and carry out strict regulatory measures with which to prevent these poisonings.The programme to reintroduce the cinereous vulture into the Catalan pre-Pyrenees has been funded by “Obra Social la Caixa” (through a contract with the “Generalitat de Catalunya”), the “Red Eléctrica de España” and the “Fundación Biodiversidad” from the Spanish Ministry of Ecological Transition and Demographic Challenge (MITECO).Peer reviewe