Combining Thermal Desorption with Selected Ion Flow Tube Mass Spectrometry for Analyses of Breath Volatile Organic Compounds.

An instrument integrating thermal desorption (TD) to selected ion flow tube mass spectrometry (SIFT-MS) is presented, and its application to analyze volatile organic compounds (VOCs) in human breath is demonstrated for the first time. The rationale behind this development is the need to analyze breath samples in large-scale multicenter clinical projects involving thousands of patients recruited in different hospitals. Following adapted guidelines for validating analytical techniques, we developed and validated a targeted analytical method for 21 compounds of diverse chemical class, chosen for their clinical and biological relevance. Validation has been carried out by two independent laboratories, using calibration standards and real breath samples from healthy volunteers. The merging of SIFT-MS and TD integrates the rapid analytical capabilities of SIFT-MS with the capacity to collect breath samples across multiple hospitals. Thanks to these features, the novel instrument has the potential to be easily employed in clinical practice.

Detecting fluoxetine and norfluoxetine in wild bird tissues and feathers.

The contamination of the environment with human pharmaceuticals is widespread and demand for such products is mounting globally. Wild vertebrates may be at particular risk from any effects from pharmaceuticals, because of the evolutionary conservation of drug targets. However, exposure of wildlife to pharmaceuticals is poorly characterised, partly due to challenges associated with detecting rapidly metabolised compounds. As part of a wider study on the behavioural effects of fluoxetine (Prozac) on Eurasian starlings (Sturnus vulgaris), we investigated which avian samples are best suited for detecting exposure to fluoxetine in free-living birds. We analysed plasma, various tissues and tail feathers (grown both in the wild and in captivity during the dosing period) from fluoxetine-treated birds (dosed daily with 0.035 mg kg-1 bodyweight for 28 weeks), and liver tissue and tail feathers from sham-dosed birds. We detected fluoxetine in only two of twelve plasma samples from dosed birds. In dosed birds, median concentrations of free fluoxetine/norfluoxetine in tissues (two hour post-final dose) were: 111.2/67.6 ng g-1 in liver, 29.6/5.7 ng g-1 in kidney, 14.2/4.0 ng g-1 in lung, 15.1/1.6 ng g-1 in brain. We estimated that fluoxetine would remain detectable in liver and kidney approximately 4.5 times longer (90 h) than in brain (20h). In dosed birds, fluoxetine was detected in feathers regrown during the dosing period (median concentration = 11.4 ng g-1) at concentrations significantly higher than in regrown feathers from control birds. Fluoxetine residues were detected in wild-grown feathers (grown before the birds were brought into captivity) at concentrations up to 27.0 ng g-1, providing some evidence of likely exposure in the wild. Our results show liver and kidney can be used for detecting fluoxetine in avian carcasses and provide a first indication that feathers may be useful for assessing exposure to fluoxetine, and possibly other pharmaceuticals.

Anthropogenic environmental drivers of antimicrobial resistance in wildlife.

The isolation of antimicrobial resistant bacteria (ARB) from wildlife living adjacent to humans has led to the suggestion that such antimicrobial resistance (AMR) is anthropogenically driven by exposure to antimicrobials and ARB. However, ARB have also been detected in wildlife living in areas without interaction with humans. Here, we investigated patterns of resistance in Escherichia coli isolated from 408 wild bird and mammal faecal samples. AMR and multi-drug resistance (MDR) prevalence in wildlife samples differed significantly between a Sewage Treatment Plant (STP; wastes of antibiotic-treated humans) and a Farm site (antibiotic-treated livestock wastes) and Central site (no sources of wastes containing anthropogenic AMR or antimicrobials), but patterns of resistance also varied significantly over time and between mammals and birds. Over 30% of AMR isolates were resistant to colistin, a last-resort antibiotic, but resistance was not due to the mcr-1 gene. ESBL and AmpC activity were common in isolates from mammals. Wildlife were, therefore, harbouring resistance of clinical relevance. AMR E. coli, including MDR, were found in diverse wildlife species, and the patterns and prevalence of resistance were not consistently associated with site and therefore different exposure risks. We conclude that AMR in commensal bacteria of wildlife is not driven simply by anthropogenic factors, and, in practical terms, this may limit the utility of wildlife as sentinels of spatial variation in the transmission of environmental AMR.

Environmentally relevant exposure to an antidepressant alters courtship behaviours in a songbird.

Pharmaceuticals in the environment are a recently identified global threat to wildlife, including birds. Like other human pharmaceuticals, the antidepressant fluoxetine (Prozac) enters the environment via sewage and has been detected at wastewater treatment plants. Birds foraging on invertebrates at these sites can be exposed to pharmaceuticals, although the implications of exposure are poorly understood. We conducted experiments to test whether chronic exposure to a maximally environmentally relevant concentration of fluoxetine (2.7 µg day-1) altered courtship behaviour and female reproductive physiology in wild-caught starlings (Sturnus vulgaris), a species commonly found foraging on invertebrates at wastewater treatment plants. When paired with a female over two days, males sang less and were more aggressive towards fluoxetine-treated females than controls. Fluoxetine-treated females were initially aggressive towards males, becoming significantly less aggressive by the second day. In contrast, control females expressed intermediate levels of aggression throughout. We found no effect of female treatment on female courtship behaviour. Female body condition, circulating testosterone and circulating oestradiol were unaffected by treatment and did not account for male preference. Our findings suggest that exposure to an antidepressant reduced female attractiveness, adding to growing evidence that environmental concentrations of pharmaceuticals can alter important traits related to individual fitness and population dynamics.