Development of a QuEChERS method for simultaneous analysis of antibiotics in carcasses for supplementary feeding of endangered vultures.

Antibiotics have been beneficial for human and animal health. However, an excessive use in livestock and a deficient management of the carcasses can lead to adverse effects in the scavengers that ingest them, especially in "supplementary feeding sites" (SFS). The aim of this study was to assess the potential risk of exposure to antibiotics for an endangered population of Cinereous vultures (Aegypius monachus) from southeastern Portugal. Hence, a multi-residue method based on QuEChERs was adapted and validated to analyse, in small volumes of tissues, the most frequent antibiotics used in livestock. The method was applied to 87 samples of liver, muscle and kidney from 7 goats and 25 sheep disposed in SFS. According to questionnaires to farmers, the animals had not been treated with antibiotics, but analyses showed residues in 29% of the samples. Antibiotics were more frequent in goats (42.9%) than in sheep (24.2%), and oxytetracycline and trimethoprim were the most common (both 13.8%). Oxytetracycline, the most common antibiotic for livestock in Portugal, showed the highest concentration (1452.68 ng g-1). To our knowledge, this is the first study of presence of antibiotics in carrion from SFS. The concentrations of antibiotics in carrion do not seem to pose a risk of acute intoxication for adult Cinereous vultures. However, subtle and likely chronic exposure with unknown health consequences may occur, which requires more research. Moreover, the results of this first study can be used in future studies to assess the risk for avian scavengers.

Comparative value of microscopy, serology and real time pcr in the diagnosis of asymptomatic canine Leishmania infantum infection

Se investigó la sensibilidad (SE) del examen citológico mediante microscopia óptica (MO) de improntas de bazo y linfonodo, de la prueba de anticuerpos ELISA (inmuno-ensayo ligado a enzima) y de la PCR (reacción en cadena de la polimerasa) a tiempo real (tr), para diagnosticar la infección asintomática por Leishmania infantum en 110 perros aparentemente sanos, del sureste de España. El porcentaje de perros positivos a MO, ELISA y PCRtr fue 2% (2/110), 27% (26/97) y 67% (39/58), respectivamente, aunque el porcentaje de PCR-positivos osciló entre 35-41% para cada tejido individualmente y 9% en sangre. La SE estimada (intervalos de confianza del 95%) de la MO en relación a la PCRtr y al ELISA fue 5% (0-12) y 8% (0-18), respectivamente. Estos resultados confirman que la mayoría de perros aparentemente sanos de una población endémica de L. infantum están infectados, que aproximadamente solo la tercera parte de éstos desarrolla anticuerpos frente al parásito y solo unos pocos tienen suficiente carga parasitaria en tejido linfoide como para ser detectada mediante MO. Consecuentemente, el grado de concordancia de la PCRtr, el ELISA y la MO en el diagnóstico de leishmaniosis canina asintomática es escaso (AU)

The sensitivity (SE) of cytological examination of spleen and lymphnode smears by optical microscopy (OM), antibody-ELISA (enzyme-linked immunosorbent assays) and real-time (rt) PCR (polymerase chain reaction), for diagnosing asymptomatic canine Leishmania infantum infection was investigated in 110 apparently healthy dogs from southeast Spain. The percentage of OM, ELISA and rtPCR positive dogs were 2% (2/110), 27% (26/97) y 67% (39/58), respectively, although the percentage of rtPCR-positive dogs were 35-41% in individual tissues and 9% in blood. The estimated SE (95% confidence interval) of OM relative to the rtPCR and ELISA tests was 5% (0-12) and 8% (0-18), respectively. Results confirm that most apparently healthy dogs from L. infantum endemic areas are infected, that approximately only one third of these infected dogs develop antibodies and that very few have parasite loads that are high enough to allow detection by OM. As a result, the degree of agreement between rtPCR, ELISA and OM for L. infantum diagnosis in subclinnically infected dogs is low (AU)

Cryptic Leishmaniosis by Leishmania infantum, a feature of canines only? A study of natural infection in wild rabbits, humans and dogs in southeastern Spain.

An epidemiological study was carried out to investigate asymptomatic Leishmania infantum infection by PCR and ELISA in wild rabbits, humans and domestic dogs in southeastern Spain. Seroprevalence was 0% (0/36) in rabbits, 2% (13/657) in humans and 7% (14/208) in dogs. The prevalence of PCR-positives was 0.6% (1/162) in rabbits tested in a wide range of tissue samples, 2% (8/392) in humans analysed in blood samples and 10% (20/193) and 67% (29/43) in dogs analysed in blood and lymphoid tissue samples, respectively. Results suggest that wild rabbits have a very low risk of becoming chronically infected with L. infantum, and provide further evidence that cryptic L. infantum infection is widespread in the domestic dog population and is also present in a comparatively smaller proportion of healthy humans. The epidemiological and clinical implications of these findings are discussed.