Purpose

Urinary Tract InfectionAQ1 (UTI) affects over 400 million people annually and globally and is a major reason for empiric antibiotic prescription by general practitioners (GPs).

Background

A problem related to microbiological UTI diagnosis is the current lack of point of care (POC) diagnostics. In addition, remote settings, including low and middle income countries (LMIC), are hard to service. Compliance with requirements posed by the In Vitro Diagnostic Regulation (IVDR) and adherence to guidelines as defined by professional user groups are mandatory to pursue. In addition, the World Health Organisation (WHO) promotes optimization of antimicrobial use and more adequate microbiological diagnostics to cure UTI and combat antimicrobial resistance (AMR).

Methods

Miniaturised chromogenic bacterial cultivation including rapid antimicrobial susceptibility testing (RAST) at the POC can be successfully used for the diagnosis of UTI. Using small and cost-effective dipsticks containing chromogenic cultivation media, UTI-causing bacteria can be detected, quantified and identified with good sensitivity and specificity.

Conclusion

Access to such trustworthy, easy-to-use and cost-efficient diagnostic tools at the POC would offer more timely results for optimised antibiotic treatment. This will improve UTI therapy and prevent AMR.

UTI-lizer is a recent digital format for easy-to-use culture-based detection, preliminary identification, and quantification of bacteria in urine at the point of care (PoC). This study aimed to evaluate the diagnostic accuracy of UTI-lizer tests for detection of bacteriuria caused by five common bacterial species: Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis, Proteus mirabilis, and Staphylococcus saprophyticus. We evaluated the accuracy of UTI-lizer tests by comparing test results of UTI-lizer with those of current standard bacterial culture-based diagnostics in clinical microbiology laboratories in a retrospective and a prospective study. Comparator methods were classical bacterial culture in combination with matrix-assisted laser desorption/ionization-time of flight mass spectrometry mediated bacterial identification. In the retrospective study, we tested 104 urine samples with in-panel microorganisms, plain urethral microbiota, and culture-negative samples. In the prospective study, we used 137 urine samples within 10 hours of their collection at general practitioner clinics. The retrospective study demonstrated 100% sensitivity and specificity in the detection of bacteriuria, and 98.6% sensitivity and 96.8% specificity in identifying primary pathogens with UTI-lizer when compared to clinical standards. S. saprophyticus and E. coli could not be distinguished. The combined nitrite and esterase test predicted the presence of bacteriuria in only 36.5% of cases. The prospective study demonstrated 100% sensitivity and 89.6% specificity in the detection of significant bacteriuria for in-panel microorganisms with a coverage rate of 88.3% (121/137). This study indicates that digital dipsticks are a promising alternative for the detection of the five main pathogens that cause the vast majority of urinary tract infections (UTIs). The results demonstrate that digital dipsticks have the potential to uniquely provide—in primary care or at the point of care—a UTI diagnostic quality on par with that of current gold-standard testing. The ease of testing, rapid test handling time, and time to result as well as simple test equipment make digital dipsticks an attractive solution for decentralized testing for bacteriuria and with that improvement in UTI diagnostics. These results motivate future studies to validate the use of UTI-lizer at the PoC setting.

“Hot flow in the cold

changes shape in a dead world

comes matter to life”

Programmable matter that allows free shape transfiguration and locomotionon command promises ubiquitous access to objects or functions of interest.Current approaches for the autonomous reshaping of solid objects (smartmaterials, soft actuators, modular robotics) are limited in spatial resolution andshape. Solid-liquid phase change pumping as a mechanism for the contactlesstransfiguring and locomotion of solid objects is introduced. Thin objects aredeformed into any intended shape with sub-millimeter resolution and the abilityto freely change their topology is demonstrated, including adding or removingholes, splitting and merging. The unique locomotion of objects throughmillimeter-sized constrictions narrower than their body size is demonstrated,followed by restoring the original shape. This approach opens up avenues fordeveloping autonomous programmable matter with free shape transfiguration.

Rapid on-site evaluation (ROSE) significantly improves the diagnostic yield of fine needle aspiration (FNA) samples but critically depends on the skills and availability of cytopathologists. Here, we introduce a portable device for semi-automated sample preparation for ROSE. In a single platform, the device combines a smearing tool and a capillary-driven chamber for staining FNA samples. Using a human pancreatic cancer cell line (PANC-1) and liver, lymph node, and thyroid FNA model samples, we demonstrate the capability of the device to prepare samples for ROSE. By minimizing the equipment needed in the operating room, the device may simplify the performance of FNA sample preparation and lead to a wider implementation of ROSE.

In sliding microfluidic platforms (“SlipChip” [1]), two plates with microfluidic wells slide in close contact to perform multiplexed reactions in a single operation. In- plane “sliding-flow” liquid transport, however, limits the potential assay operations to 1) sample compartmentalization/metering, 2) reagent addition, 3) mixing, and 4) aliquoting. Here, we introduce a three-plate sliding microfluidics platform, “Slip-X-Chip”, that additionally includes out-of-plane “cross-flow” liquid transport. Slip-X-Chip allows two additional assay operations: 5) sample concentration and 6) liquid exchange/washing, while retaining the simplicity of operation (one-step operation; no precise pipetting required; no external equipment). These additional assay operations extend the range and complexity of applications enabled by sliding microfluidics. We here demonstrate 1) splitting bead solutions in compartments with different concentrations and 2) compartmentalizing human cells from solution, followed by a viability assay. We foresee that Slip-X-Chip could be further adapted to, e.g., cell counting, cell staining, or ELISA. 

In this study, we demonstrate a digital bacterial detection assay in a dipstick format that can identify and quantitate Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis, i.e., three of the most common (>90%) bacteria causing urinary tract infections (UTIs). The operation involves nothing more than dipping the stick in urine for a few seconds and let the stick incubate for 10-12 h before read-out. Each of the 180 miniaturised culture wells in the stick contain chromogenic agar and change colour if they contain a CFU. The colour of the wells identifies the presence of a specific type of bacteria; the number of coloured wells indicates the concentration. This format allows detection and quantification at a potentially low cost and without the need for complicated external equipment or technical skills. 

Structures that are periodic on a microscale in three dimensions are abundant in nature, for example, in the cellular arrays that make up living tissue. Such structures can also be engineered, appearing in smart materials(1-4), photonic crystals(5), chemical reactors(6), and medical(7) and biomimetic(8) technologies. Here we report that fluid-fluid interfacial energy drives three-dimensional (3D) structure emergence in a micropillar scaffold. This finding offers a rapid and scalable way of transforming a simple pillar scaffold into an intricate 3D structure that is periodic on a microscale, comprising a solid microscaffold, a dispersed fluid and a continuous fluid. Structures generated with this technique exhibit a set of unique features, including a stationary internal liquid-liquid interface. Using this approach, we create structures with an internal liquid surface in a regime of interest for liquid-liquid catalysis. We also synthesize soft composites in solid, liquid and gas combinations that have previously not been shown, including actuator materials with temperature-tunable microscale pores. We further demonstrate the potential of this method for constructing 3D materials that mimic tissue with an unprecedented level of control, and for microencapsulating human cells at densities that address an unresolved challenge in cell therapy.

Established digital bioassay formats, digital PCR and digital ELISA, show extreme limits of detection, absolute quantification and high multiplexing capabilities. However, they often require complex instrumentation, and extensive off-chip sample preparation. In this study, we present a dipstick-format digital biosensor (digital dipstick) that detects bacteria directly from the sample liquid with a minimal number of steps: dip, culture, and count. We demonstrate the quantitative detection of Escherichia coli (E. coli) in urine in the clinically relevant range of 10² –10⁵ CFU ml⁻¹ for urinary tract infections. Our format shows 89% sensitivity to detect E. coli in clinical urine samples (n = 28) when it is compared to plate culturing (gold standard). The significance and uniqueness of this diagnostic test format is that it allows a non-trained operator to detect urinary tract infections in the clinically relevant range in the home setting.