Biochips for Direct Detection and Identification of Bacteria in Blood Culture-Like Conditions

Rapid and receptor-free Prussian blue electrochemical sensor for the detection of pathogenic bacteria in blood

Bloodstream bacterial infections, a major health concern due to rising sepsis rates, require prompt, cost-effective diagnostics. Conventional methods, like CO2-based transduction, face challenges such as volatile metabolites, delayed gas-phase signaling, and the need for additional instruments, whereas electrochemical sensors provide rapid, sensitive, and efficient real-time detection. In this study, we developed a bioreceptor-free Prussian blue (PB) sensor platform for real-time bacterial growth monitoring in blood culture. PB thin films were electrodeposited onto a screen-printed carbon electrode (SPCE) via cyclic voltammetry (CV) technique under optimal conditions. The electrochemical performance of PB/SPCE was assessed using differential pulse voltammetry (DPV) against exoelectrogenic bacteria, including E. coli, P. aeruginosa, S. aureus, and E. faecalis. The proposed sensor exhibited surface-controlled electrochemical kinetics and bacteria-driven metal reduction from PB to Prussian white (PW), facilitated by extracellular electron transfer (EET). It showed significant sensitivity with an extensive detection range of 102-108 CFU/mL for E. coli and S. aureus, and 103-108 CFU/mL for P. aeruginosa and E. faecalis, with reliable detection limits. The sensor accessed the viability of the pathogen within 3 hrs, offering a rapid, efficient alternative to traditional, labor-intensive methods for blood-based diagnostics.

Investigation of the Affinity of Aptamers for Bacteria by Surface Plasmon Resonance Imaging Using Nanosomes

The cell-SELEX method enables efficient selection of aptamers that bind whole bacterial cells. However, after selection, it is difficult to determine their binding affinities using common screening methods because of the large size of the bacteria. Here we propose a simple surface plasmon resonance imaging method (SPRi) for aptamer characterization using bacterial membrane vesicles, called nanosomes, instead of whole cells. Nanosomes were obtained from membrane fragments after mechanical cell disruption in order to preserve the external surface epitopes of the bacterium used for their production. The study was conducted on Bacillus cereus (B. cereus), a Gram-positive bacterium commonly found in soil, rice, vegetables, and dairy products. Four aptamers and one negative control were initially grafted onto a biochip. The binding of B. cereus cells and nanosomes to immobilized aptamers was then compared. The use of nanosomes instead of cells provided a 30-fold amplification of the SPRi signal, thus allowing the selection of aptamers with higher affinities. Aptamer SP15 was found to be the most sensitive and selective for B. cereus ATCC14579 nanosomes. It was then truncated into three new sequences (SP15M, SP15S1, and SP15S2) to reduce its size while preserving the binding site. Fitting the results of the SPRi signal for B. cereus nanosomes showed a similar trend for SP15 and SP15M, and a slightly higher apparent association rate constant kon for SP15S2, which is the truncation with a high probability of a G-quadruplex structure. These observations were confirmed on nanosomes from B. cereus ATCC14579 grown in milk and from the clinical strain B. cereus J066. The developed method was validated using fluorescence microscopy on whole B. cereus cells and the SP15M aptamer labeled with a rhodamine. This study showed that nanosomes can successfully mimic the bacterial membrane with great potential for facilitating the screening of specific ligands for bacteria.

Burden of bacterial bloodstream infections and recent advances for diagnosis

Bloodstream infections (BSIs) and subsequent organ dysfunction (sepsis and septic shock) are conditions that rank among the top reasons for human mortality and have a great impact on healthcare systems. Their treatment mainly relies on the administration of broad-spectrum antimicrobials since the standard blood culture-based diagnostic methods remain time-consuming for the pathogen's identification. Consequently, the routine use of these antibiotics may lead to downstream antimicrobial resistance and failure in treatment outcomes. Recently, significant advances have been made in improving several methodologies for the identification of pathogens directly in whole blood especially regarding specificity and time to detection. Nevertheless, for the widespread implementation of these novel methods in healthcare facilities, further improvements are still needed concerning the sensitivity and cost-effectiveness to allow a faster and more appropriate antimicrobial therapy. This review is focused on the problem of BSIs and sepsis addressing several aspects like their origin, challenges, and causative agents. Also, it highlights current and emerging diagnostics technologies, discussing their strengths and weaknesses.

Technique Evolutions for Microorganism Detection in Complex Samples: A Review

Rapid detection of microorganisms is a major challenge in the medical and industrial sectors. In a pharmaceutical laboratory, contamination of medical products may lead to severe health risks for patients, such as sepsis. In the specific case of advanced therapy medicinal products, contamination must be detected as early as possible to avoid late production stop and unnecessary costs. Unfortunately, the conventional methods used to detect microorganisms are based on time-consuming and labor-intensive approaches. Therefore, it is important to find new tools to detect microorganisms in a shorter time frame. This review sums up the current methods and represents the evolution in techniques for microorganism detection. First, there is a focus on promising ligands, such as aptamers and antimicrobial peptides, cheaper to produce and with a broader spectrum of detection. Then, we describe methods achieving low limits of detection, thanks to Raman spectroscopy or precise handling of samples through microfluids devices. The last part is dedicated to techniques in real-time, such as surface plasmon resonance, preventing the risk of contamination. Detection of pathogens in complex biological fluids remains a scientific challenge, and this review points toward important areas for future research.

Pilot Testing of the "Turbidimeter", a Simple, Universal Reader Intended to Complement and Enhance Bacterial Growth Detection in Manual Blood Culture Systems in Low-Resource Settings

Bloodstream infections and antimicrobial resistance are an increasing problem in low-income countries. There is a clear need for adapted diagnostic tools. To address this need, we developed a simple, universal reader prototype that detects bacterial growth in blood culture bottles. Our "turbidimeter" evaluates bacterial growth, based on the turbidity of the broth and the color change of the colorimetric CO2 indicator in commercially available blood culture bottles. A total of 60 measurements were performed using 10 relevant microbial species, spiked in horse blood, to compare the turbidimeter's performance with that of an automatic reference system. The turbidimeter was able to detect growth in all but one of the spiked blood culture bottles. In the majority (7/10) of the species tested, time-to-detection of the turbidimeter was shown to be non-inferior to the reference automated time-to-detection. This was, however, only the case when both the turbidity and color change in the colorimetric CO2-indicator were used to evaluate growth. We could not demonstrate the non-inferiority of the turbidity measurement alone. Overall, the turbidimeter performed well, but we also identified some improvements that will be implemented in the next version of the prototype.

Bandemia as an Early Predictive Marker of Bacteremia: A Retrospective Cohort Study

This single-center retrospective observational study aimed to verify whether a diagnosis of bandemia could be a predictive marker for bacteremia. We assessed 970 consecutive patients (median age 73 years; male 64.8%) who underwent two or more sets of blood cultures between April 2015 and March 2016 in both inpatient and outpatient settings. We assessed the value of bandemia (band count > 10%) and the percentage band count for predicting bacteremia using logistic regression models. Bandemia was detected in 151 cases (15.6%) and bacteremia was detected in 188 cases (19.4%). The incidence of bacteremia was significantly higher in cases with bandemia (52.3% vs. 13.3%; odds ratio (OR) = 7.15; 95% confidence interval (CI) 4.91–10.5). The sensitivity and specificity of bandemia for predicting bacteremia were 0.42 and 0.91, respectively. The bandemia was retained as an independent predictive factor for the multivariable logistic regression model (OR, 6.13; 95% CI, 4.02–9.40). Bandemia is useful for establishing the risk of bacteremia, regardless of the care setting (inpatient or outpatient), with a demonstrable relationship between increased risk and bacteremia. A bandemia-based electronic alert for blood-culture collection may contribute to the improved diagnosis of bacteremia.

Multiplexed detection and differentiation of bacterial enzymes and bacteria by color-encoded sensor hydrogels

We report on the fabrication and characterization of color-encoded chitosan hydrogels for the rapid, sensitive and specific detection of bacterial enzymes as well as the selective detection of a set of tested bacteria through characteristic enzyme reactions. These patterned sensor hydrogels are functionalized with three different colorimetric enzyme substrates affording the multiplexed detection and differentiation of α-glucosidase, β-galactosidase and β-glucuronidase. The limits of detection of the hydrogels for an observation time of 60 min using a conventional microplate reader correspond to concentrations of 0.2, 3.4 and 4.5 nM of these enzymes, respectively. Based on their different enzyme expression patterns, Staphylococcus aureus strain RN4220, methicillin-resistant S. aureus (MRSA) strain N315, both producing α-glucosidase, but not β-glucuronidase and β-galactosidase, Escherichia coli strain DH5α, producing β-glucuronidase and α-glucosidase, but not β-galactosidase, and the enterohemorrhagic E. coli (EHEC) strain E32511, producing β-galactosidase, but none of the other two enzymes, can be reliably and rapidly distinguished from each other. These results confirm the applicability of enzyme sensing hydrogels for the detection and discrimination of specific enzymes to facilitate differentiation of bacterial strains. Patterned hydrogels thus possess the potential to be further refined as detection units of a multiplexed format to identify certain bacteria for future application in point-of-care microbiological diagnostics in food safety and medical settings.

Label-Free Immunoassay for Multiplex Detections of Foodborne Bacteria in Chicken Carcass Rinse with Surface Plasmon Resonance Imaging

The frequent outbreaks of foodborne pathogens have stimulated the demand of biosensors capable of rapid and multiplex detection of contaminated food. In this study, surface plasmon resonance imaging (SPRi) was used in simultaneous label-free detection of multiple foodborne pathogens, mainly Salmonella spp. and Shiga-toxin producing Escherichia coli (STEC), in commercial chicken carcass rinse. The antibodies were immobilized on the same SPRi sensor chip as a label-free immunoassay. Their immobilization concentrations were optimized to be ranging from 0.25 to 1.0 mg/mL, and independent of pH values. This label-free immunoassay achieved 10⁶ colony-forming unit (CFU)/mL limit of detection for Salmonella, which was further improved to 1.0 CFU/mL with overnight bacteria enrichment. The injected samples with different bacteria, Salmonella Enteritidis, STEC, and Listeria monocytogenes, have been identified by the same biochip. Moreover, the SPRi signals revealed complex interference effects among coexisting bacteria species in heterogeneous bacteria solutions. This SPRi-based immunoassay demonstrates the great potential in high-throughput screening of multiple pathogenic bacteria coexisting in chicken carcass rinse. The reliability of antibody immobilization and cross-reactions of different antibodies on the same biochip are the major challenges of practical application of SPRi.

Rapid and sensitive identification of uropathogenic Escherichia coli using a surface-enhanced-Raman-scattering-based biochip

Rapid, selective and sensitive sensing of bacteria remains challenging. We report on a highly sensitive and reproducible surface-enhanced Raman spectroscopy (SERS)-based sensing approach for the detection of uropathogenic Escherichia coli (E. coli) bacteria in urine. The assay is based on the specific capture of the bacteria followed by interaction with cetyltrimethylammonium bromide (CTAB)-stabilised gold nanorods (Au NRS) as SERS markers. High sensitivity up to 10 CFU mL^-1 is achieved by optimizing the capture interface based on hydrogenated amorphous silicon a-Si:H thin films. The integration of CH₃O-PEG750 onto a-Si:H gives the sensing interface an efficient anti-fouling character, while covalent linkage of antibodies directed against the major type-1 fimbrial pilin FimA of the human pathogen E. coli results in the specific trapping of fimbriated E. coli onto the SERS substrate and their spectral fingerprint identification.

Development of a Prototype Lateral Flow Immunoassay for Rapid Detection of Staphylococcal Protein A in Positive Blood Culture Samples

Bloodstream infection (BSI) is a major cause of mortality in hospitalized patients worldwide. Staphylococcus aureus is one of the most common pathogens found in BSI. The conventional workflow is time consuming. Therefore, we developed a lateral flow immunoassay (LFIA) for rapid detection of S. aureus-protein A in positive blood culture samples. A total of 90 clinical isolates including 58 S. aureus and 32 non-S. aureus were spiked in simulated blood samples. The antigens were extracted by a simple boiling method and diluted before being tested using the developed LFIA strips. The results were readable by naked eye within 15 min. The sensitivity of the developed LFIA was 87.9% (51/58) and the specificity was 93.8% (30/32). When bacterial colonies were used in the test, the LFIA provided higher sensitivity and specificity (94.8% and 100%, respectively). The detection limit of the LFIA was 10⁷ CFU/mL. Initial evaluation of the LFIA in 20 positive blood culture bottles from hospitals showed 95% agreement with the routine methods. The LFIA is a rapid, simple and highly sensitive method. No sophisticated equipment is required. It has potential for routine detection particularly in low resource settings, contributing an early diagnosis that facilitates effective treatment and reduces disease progression.

Age, Period and Cohort Analysis of Rates of Emergency Department Visits Due to Pneumonia in Taiwan, 1998-2012

Background

Emergency room (ER) physicians need to face clinically suspected pneumonia patients in the front line of medical care and must do to give major medical interventions if patients show severity in pneumonia.

Methods

The data of pneumonia-related ER visit rates were categorized based on the International Classification of Disease (ICD) Codes (480–486) between 1998 and 2012. We use an age-period-cohort (APC) model to separate the pneumonia-related ER visit rates to identify the effects of age, time period, and cohort for a total of 1,813,588 patients.

Results

The age effect showed high risk for pediatric and elder populations. There is a significant increasing period effect, which increased from 1998 to 2012. The cohort effect tended to show an oscillation from 1913 to 1988 and the reverse in a recent cohort. Furthermore, the visit rate of pneumonia showed an increase from 1998 to 2012 for both genders.

Conclusion

Age is a risk factor for pneumonia-related ER visits, especially for children and adolescents and older patients. Period and cohort effects were also found to increase the pneumonia visit rates. An APC model used to provide an advance clue for trend of pneumonia-related ER visit rates diversified.

Pectobacterium atrosepticum Biosensor for Monitoring Blackleg and Soft Rot Disease of Potato

Pectobacterium atrosepticum (Pba) is a quarantine and threatening phytopathogen known as the causal agent of blackleg and soft rot disease of potatoes in many areas. Its early detection is then important to have healthy potato tubers and reduce economic losses. Today, conventional methods such as enzyme-linked immunosorbent-assay (ELISA) and polymerase chain reaction (PCR) are typically used for Pba detection, but they are expensive and time-consuming. Here we report on the optimization of an alternative approach based on an electrochemical impedance immunosensor combining a microfluidic module and a microelectrodes array, and having advantages in terms of low cost, ease of use and portability. For validation and for assessing its performance, the lab-on-chip platform has been compared with two standard methods (ELISA and PCR).

Antimicrobial Peptides as Probes in Biosensors Detecting Whole Bacteria: A Review

Bacterial resistance is becoming a global issue due to its rapid growth. Potential new drugs as antimicrobial peptides (AMPs) are considered for several decades as promising candidates to circumvent this threat. Nonetheless, AMPs have also been used more recently in other settings such as molecular probes grafted on biosensors able to detect whole bacteria. Rapid, reliable and cost-efficient diagnostic tools for bacterial infection could prevent the spread of the pathogen from the earliest stages. Biosensors based on AMPs would enable easy monitoring of potentially infected samples, thanks to their powerful versatility and integrability in pre-existent settings. AMPs, which show a broad spectrum of interactions with bacterial membranes, can be tailored in order to design ubiquitous biosensors easily adaptable to clinical settings. This review aims to focus on the state of the art of AMPs used as the recognition elements of whole bacteria in label-free biosensors with a particular focus on the characteristics obtained in terms of threshold, volume of sample analysable and medium, in order to assess their workability in real-world applications.

Microarray Strategies for Exploring Bacterial Surface Glycans and Their Interactions With Glycan-Binding Proteins

Bacterial surfaces are decorated with distinct carbohydrate structures that may substantially differ among species and strains. These structures can be recognized by a variety of glycan-binding proteins, playing an important role in the bacteria cross-talk with the host and invading bacteriophages, and also in the formation of bacterial microcolonies and biofilms. In recent years, different microarray approaches for exploring bacterial surface glycans and their recognition by proteins have been developed. A main advantage of the microarray format is the inherent miniaturization of the method, which allows sensitive and high-throughput analyses with very small amounts of sample. Antibody and lectin microarrays have been used for examining bacterial glycosignatures, enabling bacteria identification and differentiation among strains. In addition, microarrays incorporating bacterial carbohydrate structures have served to evaluate their recognition by diverse host/phage/bacterial glycan-binding proteins, such as lectins, effectors of the immune system, or bacterial and phagic cell wall lysins, and to identify antigenic determinants for vaccine development. The list of samples printed in the arrays includes polysaccharides, lipopoly/lipooligosaccharides, (lipo)teichoic acids, and peptidoglycans, as well as sequence-defined oligosaccharide fragments. Moreover, microarrays of cell wall fragments and entire bacterial cells have been developed, which also allow to study bacterial glycosylation patterns. In this review, examples of the different microarray platforms and applications are presented with a view to give the current state-of-the-art and future prospects in this field.

Label-Free Electrochemical Detection of S. mutans Exploiting Commercially Fabricated Printed Circuit Board Sensing Electrodes

This paper reports for the first time printed-circuit-board (PCB)-based label-free electrochemical detection of bacteria. The demonstrated immunosensor was implemented on a PCB sensing platform which was designed and fabricated in a standard PCB manufacturing facility. Bacteria were directly captured on the PCB sensing surface using a specific, pre-immobilized antibody. Electrochemical impedance spectra (EIS) were recorded and used to extract the charge transfer resistance (R_ct) value for the different bacteria concentrations under investigation. As a proof-of-concept, Streptococcus mutans (S. mutans) bacteria were quantified in a phosphate buffered saline (PBS) buffer, achieving a limit of detection of 10³ CFU/mL. Therefore, the proposed biosensor is an attractive candidate for the development of a simple and robust point-of-care diagnostic platform for bacteria identification, exhibiting good sensitivity, high selectivity, and excellent reproducibility.

Near real-time enumeration of live and dead bacteria using a fibre-based spectroscopic device

A rapid, cost-effective and easy method that allows on-site determination of the concentration of live and dead bacterial cells using a fibre-based spectroscopic device (the optrode system) is proposed and demonstrated. Identification of live and dead bacteria was achieved by using the commercially available dyes SYTO 9 and propidium iodide, and fluorescence spectra were measured by the optrode. Three spectral processing methods were evaluated for their effectiveness in predicting the original bacterial concentration in the samples: principal components regression (PCR), partial least squares regression (PLSR) and support vector regression (SVR). Without any sample pre-concentration, PCR achieved the most reliable results. It was able to quantify live bacteria from 108 down to 106.2 bacteria/mL and showed the potential to detect as low as 105.7 bacteria/mL. Meanwhile, enumeration of dead bacteria using PCR was achieved between 108 and 107 bacteria/mL. The general procedures described in this article can be applied or modified for the enumeration of bacteria within populations stained with fluorescent dyes. The optrode is a promising device for the enumeration of live and dead bacterial populations particularly where rapid, on-site measurement and analysis is required.

Genotyping Citrus tristeza virus Isolates by Sequential Multiplex RT-PCR and Microarray Hybridization in a Lab-on-Chip Device

Citrus tristeza virus (CTV) is the largest known plant RNA virus (ca. 20 Kb), with a plethora of isolates conventionally categorized into six main genotypic groups (T36, VT, T3, RB, T68, T30). Each group includes many isolates with different phenotype profiles. Several techniques and protocols, mostly based on RT-PCR analysis of different regions of specific genes, have been developed for managing the diseases caused by CTV. However, more accurate genomic information would help to plan a correct strategy. This chapter describes a pilot protocol based on a sequential multiplex RT-PCR reaction and microarray hybridization in a miniaturized silicon lab-on-chip (LoC) device. The system comprises a set of 12 primers and 44 probes (× 2 replicates), designed on variable genomic regions of 6 genes: 5'UTR, ORF1a, ORF1b (RdRp), p33, p20, and p23. The system can rapidly analyze any genotype diversity associated with field isolates and distinguish the endemic from the non-endemic isolates. The identification of CTV strains is based on a number of probe hybridizations, which varies according to the genotypes present in the isolates and the differences among the genotypes.

‘Off–on’ switchable fluorescent probe for prompt and cost-efficient detection of bacteria

The rapid and straightforward detection of bacteria in food and human samples is becoming important, particularly in view of the development of point-of-care devices and lab-on-a-chip tools for prevention and treatment of bacterial infections.

Highly-Selective Optoelectronic Nose Based on Surface Plasmon Resonance Imaging for Sensing Volatile Organic Compounds

Monitoring volatile organic compounds (VOCs) is an important issue, but difficult to achieve on a large scale and on the field using conventional analytical methods. Electronic noses (eNs), as promising alternatives, are still compromised by their performances due to the fact that most of them rely on a very limited number of sensors and use databases devoid of kinetic information. To narrow the performance gap between human and electronic noses, we developed a novel optoelectronic nose, which features a large sensor microarray that enables multiplexed monitoring of binding events in real-time with a temporal response. For the first time, surface plasmon resonance imaging is demonstrated as a promising novel analytical tool for VOC detection in the gas phase. By combining it with cross-reactive sensor microarrays, the obtained optoelectronic nose shows a remarkably high selectivity, capable of discriminating between homologous VOCs differing by only a single carbon atom. In addition, the optoelectronic nose has good repeatability and stability. Finally, the preliminary assays using VOC binary and ternary mixtures show that it is also very efficient for the analysis of more complex samples, opening up the exciting perspective of applying it to "real-world" samples in diverse domains.

A review of novel technologies and techniques associated with identification of bloodstream infection etiologies and rapid antimicrobial genotypic and quantitative phenotypic determination

INTRODUCTION

The antimicrobial aspect of management of patients with blood stream infections (BSI) and sepsis is time critical. In an era of increasing antimicrobial resistance, rapid detection and identification of bacteria with antimicrobial susceptibility is crucial to direct therapy early in the course of illness. Molecular techniques offer a potential solution to this. Areas covered: In the present review the authors have discussed a number of novel solutions utilizing a variety of molecular techniques for pathogen detection, identification and antimicrobial susceptibility. The review is not designed to be an exhaustive literature review covering all diagnostic solutions ever developed, instead the authors have focused on what they have had experience using, evaluating or currently view as new and exciting with potential to revolutionize BSI diagnosis. The authors searched PubMed (Medline) and Google Scholar with terms: BSI, Bacteraemia, Candidaemia, Diagnostics, AST, Rapid, AMR, Novel and Blood Culture. The authors attended recent clinical microbiology technology congresses. Expert commentary: There are multiple exciting novel technologies at differing stages of development with potential to revolutionize diagnosis of BSI. More work is needed as well as a standardized assessment of different platforms in order to better understand the clinical and financial impacts these will have in clinical microbiology laboratories.

Development of a lab-on-a-chip method for rapid assay of Xylella fastidiosa subsp. pauca strain CoDiRO

Xylella fastidiosa subsp. pauca strain CoDiRO, a pathogen responsible for Olive Quick Decline Syndrome (OQDS), is strongly threatening the agricultural-based economy of South Italy and making its typical landscape collapse. The bacteria can also infect more than other twenty woody or shrub species and quarantine programs are carried out in Italy. Since symptoms of OQDS like leaf scorching and wilting of canopy may appear several months after infection and some hosts are asymptomatic, a tool for the rapid and early screening of plants is desirable, in order to plan a sudden control strategy and apply programs for pest management. X. fastidiosa detection is usually performed by ELISA and PCR methods. In this work, the two standard methods are compared with an innovative on-chip detection strategy for X. fastidiosa assay from leaves samples, based on an electrochemical transduction method. The realized lab-on-chip includes also a microfluidic module and its performances are competitive with conventional diagnostic methods in terms of reliability, but with further advantages of portability, low-costs and ease of use. Thus, the proposed technology has the potential to provide a useful assay method for large-scale monitoring programs.

Recent advances in the microbiological diagnosis of bloodstream infections

Rapid identification (ID) and antimicrobial susceptibility testing (AST) of the causative agent(s) of bloodstream infections (BSIs) are essential for the prompt administration of an effective antimicrobial therapy, which can result in clinical and financial benefits. Immediately after blood sampling, empirical antimicrobial therapy, chosen on clinical and epidemiological data, is administered. When ID and AST results are available, the clinician decides whether to continue or streamline the antimicrobial therapy, based on the results of the in vitro antimicrobial susceptibility profile of the pathogen. The aim of the present study is to review and discuss the experimental data, advantages, and drawbacks of recently developed technological advances of culture-based and molecular methods for the diagnosis of BSI (including mass spectrometry, magnetic resonance, PCR-based methods, direct inoculation methods, and peptide nucleic acid fluorescence in situ hybridization), the understanding of which could provide new perspectives to improve and fasten the diagnosis and treatment of septic patients. Although blood culture remains the gold standard to diagnose BSIs, newly developed methods can significantly shorten the turnaround time of reliable microbial ID and AST, thus substantially improving the diagnostic yield.