Campaign-Based Citizen Science for Environmental Mycology: the “Science Solstice” and “Summer Soil-stice” Projects to Assess Drug Resistance in Air and Soilborne Aspergillus fumigatus

Citizen science projects are often undertaken for ecological and environmental research purposes but also have great potential for use in microbiology research to track the emergence and spread of pathogens in the environment. ‘Science Solstice’ and ‘Summer Soil-stice’ are mycology citizen science projects aimed at assessing drug resistance in Aspergillus fumigatus fungal spores found in air and soil, respectively, in the United Kingdom (UK). A. fumigatus plays an important role in the environment as a decomposer of plant material, but is also an opportunistic human lung pathogen. Infection with drug-resistant spores can lead to a worse clinical outcome for the patient. On the first four solstice and equinox days between June 2018 and June 2019, volunteers were asked to collect air samples from their homes and workplaces and return them to our lab in Freepost envelopes. An additional round of samples was requested from volunteer’s gardens and/or compost on the June 2019 solstice. In total, 787 volunteers returned 2,132 air samples and 509 soil samples, which grew a total of 7,991 A. fumigatus colonies. The estimated total cost of the study was £2,650; the equivalent of 33 pence per A. fumigatus colony grown. Incorporating citizen science into the environmental surveillance of drug-resistant A. fumigatus allowed for the simultaneous collection of hundreds of environmental samples across the entire UK on the same day. The insights generated from this study would not be practical in the absence of public participation and offers opportunities to ask scientific questions that were previously unaskable.


34
Citizen science is defined as the "intentional involvement, in a non-professional capacity, of 35 people in the scientific process, e.g. the collection… of data" (Pocock, 2015) and is becoming 36 increasingly popular for simultaneously conducting research and engaging with the public 37 about science. Many citizen science projects in the UK rely on volunteers to monitor population 38 levels of native insects (Gardiner, 2012;Lye, 2012;Wilson, 2018), wildlife (Hof and Bright,39 2016), birds (Cannon, 2005;Sparks, 2017) and plants (Rich and Woodruff, 1990;Pescott, 40 2015). Citizen scientists can also report environmental incidents with potentially harmfully 41 effects such as toxic algal blooms (Ransom Hardison, 2019) or river pollution (Hyder, 2017), 42 and can aid surveillance of invasive species (Pocock and Evans, 2014), wildlife diseases 43 (Robinson, 2010;Lawson, 2012) or plant pathogens (Brown, 2017). The majority of these 44 projects ask participants to record their observations, either online, through an app or via post 45 over a prolonged period of time. 46 Projects may also raise awareness of invisible health threats such as air pollution, pathogen 47 spread and antimicrobial resistance (AMR). One example is Netherlands-based iSPEX, where 48 participants measured atmospheric aerosols on a single day using an optical add-on for their 49 smartphones with a corresponding app that collated data (Snik, 2014). A UK-based example is 50 Swab & Send: an ongoing, self-funding microbiology project asking citizen scientists to take 51 swabs of any object or environment they choose to help identify new antibiotic compounds 52 (www.lstmed.ac.uk/public-engagement/swab-send). Public health-focused projects like these 53 provided the inspiration for this study. We asked volunteers to collect samples from the air and invasive aspergillosis (IA) (Pegorie, 2017). IA has a mortality rate ranging from 30-80% 63 (Bongomin, 2017) and its prevalence is increasing in the UK due to increasing numbers of 64 patients receiving immunosuppressive therapies for transplant, cancer or autoimmune 65 conditions and the ageing population (Löbermann, 2012 (Gilbert, 2003). Further studies have collected air and/or soil give valuable insight but are limited in sample number and coverage due to sample collection 89 being undertaken by the study authors themselves. In order to address some of these problems, 90 this study reports the UK-wide collection of outdoor air and soil samples by citizen scientists, 91 in a campaign-based, single timepoint manner, from which A. fumigatus spores were cultured 92 and will ultimately be tested for azole antifungal-resistance.

95
The aims of this citizen science project were to monitor for drug-resistant A. fumigatus spores 96 in outdoor air and soil across the UK at multiple timepoints. The 'citizen science' methodology 97 of the study had several rationales: 1) to provide a step-change in UK spatial coverage from 98 previous studies, 2) to raise awareness of aspergillosis diseases amongst the general public, and 99 3) to trial the efficacy of the chosen sample collection methods on citizen scientists as a viable 100 approach for mycological research. The outcome of the study will be to determine whether 101 there are spatial or temporal determinants of resistance that could inform future policies to 102 protect those at risk for aspergillosis. 103 We thereby asked individuals residing in the UK to collect spore samples from their local air  is iconic for such celestial events; all in an effort to make the sampling dates memorable. The 119 posters also contained a brief description of the project that aimed to be understandable to non-120 scientists, links to an online blog post containing further information about the project, and the 121 Twitter handles of the author and project to be followed for regular updates. Twitter was chosen 122 as a way of providing project updates because Tweets are visible to the public and did not 123 require the participants to befriend or follow the authors as on other social media platforms.

124
Twitter updates also avoided potentially upsetting participants by sending unsolicited emails.      Table 1.

245
Adherence to sampling date amongst UK samples 246 The initial air sampling round had the highest adherence to sampling date of 94%, which 247 dropped to ~60% for the second and fourth air sampling round (    were made to subsequent sampling rounds. In the first air sampling round white sticky labels 289 that read "LOCATION 1 (or 2) air sampler: please peel this off and retain, to re-cover air 290 sampler after ~8hrs." were stuck to the back of each air sampler ( Figure 4A), to correspond 291 with locations 1 and 2 on the questionnaires. It quickly became apparent on 21 st June 2018 that 292 several individuals had removed this label instead of peeling off the backing of the air sampler.

293
These individuals were contacted immediately to remedy this mistake, when possible, but 20 294 air samplers were returned that had not been exposed correctly. It is possible to tell when an 295 air sample has not been exposed because it appears white and debris-free whereas exposed air participants referred to the instruction page for exposing the air samplers.

300
Participants also commented during and after the first air sampling round that their air samplers 301 had blown away because adhesive putty was insufficiently adhesive, so for the second air 302 sampling round the author instead attached double-sided foam tape to each air sampler. After 303 the second air sampling round participants reported that the foam tape remained stuck to their 304 windowsills and required chemical removal, so for the third and fourth air sampling round the 305 author provided both adhesive putty and foam tape for participants to choose between.

306
Several participants contacted the author before, during and after the first air sampling round 307 to apologise for not taking part because they were occupied on the sampling date. As a result,

331
Organising sampling rounds to take place on single dates, which coincided with solstice and 332 equinox days, was easier for the author and likely achieved a higher return rate than ongoing 333 sampling. The author was able to send an email reminder several days before each sampling 334 date and a text reminder the evening before such that, combined with television and radio 335 broadcasts on solstice and equinox days, no participants stated they'd not taken part due to 336 having forgotten about the project. The single sampling dates also meant that the majority of 337 samples were returned in the following fortnight so the author was able to prepare and use lab 338 consumables within a short timeframe, which is helpful for sterile culturing in mycology.

339
Adherence to sampling date was exceptionally high (94%) for the first air sampling round and 340 moderate for the second and fourth air sampling rounds (~60%) but dropped for the third (12%) 341 due to winter weather conditions and proximity to Christmas. It is worth noting that the weather 342 for the first, second and fourth air sampling rounds (summer, autumn and spring, respectively) 343 was remarkably good, which likely increased participation levels and adherence to sampling 344 dates. Importantly, the range of sampling dates did not overlap between sampling rounds so 345 they can still be ascribed to different seasons as intended. Furthermore, every participant 346 recorded the date of sampling on their questionnaire so, when undertaking spatial analyses in 347 future, the authors can download meteorological data and adjust for factors such as wind speed 348 and wind direction on the day each sample was collected.

349
The cost of sample collection by citizen scientists was considerably lower than if the author