At-Home Saliva Sampling in Healthy Adults Using CandyCollect, a Lollipop-Inspired Device

Abstract

Respiratory infections are common in children, and there is a need for user-friendly collection methods. Here, we performed the first human subjects study using the CandyCollect device, a lollipop-inspired saliva collection device .We showed that the CandyCollect device can be used to collect salivary bacteria from healthy adults using Streptococcus mutans and Staphylococcus aureus as proof-of-concept commensal bacteria. We enrolled healthy adults in a nationwide (USA) remote study in which participants were sent study packages containing CandyCollect devices and traditional commercially available oral swabs and spit tubes. Participants sampled themselves at home, completed usability and user preference surveys, and mailed the samples back to our laboratory for analysis by qPCR. Our results showed that for participants in which a given bacterium (S. mutans or S. aureus) was detected in one or both of the commercially available methods (oral swab and/or spit tubes), CandyCollect devices had a 100% concordance with the positive result (n = 14 participants). Furthermore, the CandyCollect device was ranked the highest preference sampling method among the three sampling methods by 26 participants surveyed (combining survey results across two enrollment groups). We also showed that the CandyCollect device has a shelf life of up to 1 year at room temperature, a storage period that is convenient for clinics or patients to keep the CandyCollect device and use it any time. Taken together, we have demonstrated that the CandyCollect is a user-friendly saliva collection tool that has the potential to be incorporated into diagnostic assays in clinic visits and telemedicine.

Development of an Integrated Sample Amplification Control for Salivary Point-of-Care Pathogen Testing

“…In addition to SARS-CoV-2, saliva could serve as specimen for other respiratory viruses [34] such as Influenza viruses, Respiratory Syncytial Virus (RSV), Adenovirus, and Rhinovirus and even bacterial pathogens such as Group A streptococci causing strep throat, and Bordetella pertussis causing whooping cough [35]. This study suggests that the 18S rRNA could be a suitable IAC for other diagnostic tests that rely on saliva samples.…”

Capture of Group A Streptococcus by Open-Microfluidic CandyCollect Device in Pediatric Patients

“…All laboratory procedures were performed in accordance with Biosafety Level-2 laboratory practices and the University of Washington Site-Specific Bloodborne Pathogen Exposure Control Plan. CandyCollect devices and mouth swabs were processed as previously described; 10 additional details are in the Supplemental Material. Briefly, the material on the CandyCollect device was eluted by phosphate buffered saline (PBS) (Gibco™, Cat# 10010023) with 5% Proteinase K (Thermo Scientific™, Cat# EO0491); for mouth swab samples, S. pyogenes DNA was isolated using MagMAX™ Total Nucleic Acid Isolation Kit (ThermoFisher Scientific, Cat# AM1840) according to the protocol supplied by the manufacturer.…”

“…The process includes decreasing the chamber pressure to 0.20-0.25 mbar and adding oxygen gas while 70 W voltage is applied for 5 minutes. 9,10 Preparation of CandyCollect devices for human subjects study: CandyCollect devices were prepared as previously described with the exception of storage containers and candy mass. 9,10 Half of the patients (1-15) were sampled with CandyCollects made with 1.2-1.34 g isomalt candy, while the second half (16-30) were sampled with 0.45-0.57 g; procedures are duplicated here for convenience.…”

“…9,10 Preparation of CandyCollect devices for human subjects study: CandyCollect devices were prepared as previously described with the exception of storage containers and candy mass. 9,10 Half of the patients (1-15) were sampled with CandyCollects made with 1.2-1.34 g isomalt candy, while the second half (16-30) were sampled with 0.45-0.57 g; procedures are duplicated here for convenience. In accordance with the kitchen hygiene guidelines of the Washington State Cottage Food Operations Law (RCW 69.22.040(2bf(ii-iv))), candy was applied to CandyCollect sticks by lab members who are trained in food safety, have a Food Worker Card (WA State), and wore gloves and a mask during food preparation.…”

“…The detailed specimen processing and laboratory analysis procedures were previously described. 10 In brief, the mouth swab and CandyCollect sample collection was obtained by a research nurse. Samples were stored in -20 °C and then transferred to storage at -80 °C within 12 days.…”