Rapid Detection Of Pathogens Research Articles

A Multiplex Nanopore Sequencing Approach for the Detection of Multiple Arboviral Species.

The emergence and continued geographic expansion of arboviruses and the growing number of infected people have highlighted the need to develop and improve multiplex methods for rapid and specific detection of pathogens. Sequencing technologies are promising tools that can help in the laboratory diagnosis of conditions that share common symptoms, such as pathologies caused by emerging arboviruses. In this study, we integrated nanopore sequencing and the advantages of reverse transcription polymerase chain reaction (RT-PCR) to develop a multiplex RT-PCR protocol for the detection of Chikungunya virus (CHIKV) and several orthoflaviviruses (such as dengue (Orthoflavivirus dengue), Zika (Orthoflavivirus zikaense), yellow fever (Orthoflavivirus flavi), and West Nile (Orthoflavivirus nilense) viruses) in a single reaction, which provides data for sequence-based differentiation of arbovirus lineages.

(Invited) Functional Nucleic Acids as Bacterial and Viral Sensors

Rapid detection of infectious pathogens is vital for preventing costless outbreaks and improving human health. Current detection methods oftentimes lack the means to detect infectious pathogens in a simple, rapid, and reliable manner at the time and point of need. Functional nucleic acids (FNAs) – specifically DNA aptamers and DNAzymes – have the potential to overcome these limitations by acting as key components for point-of-care (POC) biosensors due to their distinctive advantages that include high binding affinities and specificities, excellent chemical stability, ease of synthesis and modification, and compatibility with a variety of signal-amplification and signal-transduction mechanisms. In this presentation, I will discuss the work completed in my laboratory, in collaboration with several other groups at McMaster, towards developing simple-to-use analytical devices with integrated FNAs to detect bacterial and viral pathogens, such as E. coli, Salmonella, SARS-CoV-2, porcine epidemic diarrhea virus (PEDV), directly in water, food or clinical samples.

Simultaneous Detection of Three Subgroups of Avian Leukosis Virus Using the Nanoparticle-Assisted PCR Assay.

Nanoparticle-assisted polymerase chain reaction (nanoPCR) is a novel method for the rapid detection of pathogens. A sensitive and specific multiple nanoPCR assay was developed for simultaneous detection of avian leucosis virus (ALV) subgroups A, B and J. In this study, three pairs of primers were designed, based on the conserved region of the gp85 gene. An exploration of the optimal primer concentration and annealing temperature were carried out, for better performance of the nanoPCR assay. According to the results, the multiple nanoPCR assay amplified 336 pb, 625 bp and 167 bp fragments of ALV-A, -B and -J, respectively, and showed no cross-reactivity with irrelevant pathogens, suggesting the excellent specificity of the assay. The constructed standard DNA templates were used to estimate the limit of detection. As shown by the results, the detection limit of the nanoPCR assay was nearly 10 copies/μL. To further evaluate the detection ability of the assay, 186 clinical samples were detected using the nanoPCR assay, among which, 14 samples were confirmed as ALV positive; the results were further confirmed by sequencing. In conclusion, a highly specific and sensitive nanoPCR assay was successfully developed, which could be a useful tool for clinical diagnosis as well as for the discrimination of ALV-A, -B and -J.

Rapid and accurate detection of SARS-CoV-2 using the RHAM technology

Rapid and sensitive detection of pathogens is of utmost importance in interrupting the transmission chain of infectious diseases. In recent years, this has proven to be vital during the coronavirus disease (COVID-19) global pandemic that put countless lives at risk. Numerous molecular diagnostic methods were used, including RT-PCR, NASBA, E-SDA, E-RCA, LAMP, and RPA. However, these technologies potentially require primer optimization and complex instruments. Here, we propose the RHAM (RNase Hybridization-Assisted amplification) system as a rapid, specific, and sensitive molecular diagnosis platform. Combining the LAMP and RNase HII-mediated fluorescent reporter, the RHAM system can amplify and visualize the target in one isothermal system with high sensitivity (5 × 102 copies/mL). There was no cross-reactivity with other common respiratory viruses. Analysis of clinical samples revealed the RHAM system to generate positive signals within 15 min without false positive or negative results. The present study shows that RHAM is not only an ideal platform for detecting pathogens, such as SARS-CoV-2 but can be potentially applied in POCT settings.

Quantum dot-based lateral flow immunoassay for the rapid detection of pathogens

On October 4, 2023, the Nobel Prize in Chemistry was awarded to Moungi Bawendi, Louis Brus, and Aleksey Yekimov for the discovery and synthesis of quantum dots (QDs). The Nobel Foundation credited QDs as being the “seeds of nanoscience”. As suggested by its name, QDs are extremely small matter resembling a dot. A QD is a photoluminescent nanoparticle composed of semiconductor materials with diameters ranging between 2 and 10 nm. It often consists of only a few thousand atoms and are smaller than human cells and viruses [1,2].

A “signal off-on” fluorescence bioassay based on 2D-MoS2-tetrahedral DNA bioconjugate for rapid virus detection

In this work we present the preparation of a 2D molybdenum disulphide nanosheets (2D-MoS2) and tetrahedral DNA nanostructures (TDNs) bioconjugate, and its application to the development of a bioassay for rapid and easy virus detection. The bioconjugate has been prepared by using TDNs carrying the capture probe labelled with 6-carboxyfluoresceine (6-FAM). As case of study to assess the utility of the assay developed, we have chosen the SARS-CoV-2 virus. Hence, as probe we have used a DNA sequence complementary to a region of the SARS-CoV-2 ORF1ab gene (TDN-ORF-FAM). This 6-FAM labelled capture probe is located on the top vertex of the tetrahedral DNA nanostructure, the three left vertices of TDNs have a thiol group. These TDNs are bounded to 2D-MoS2 surface through the three thiol groups, allowing the capture probe to be oriented to favour the biorecognition reaction with the analyte. This biorecognition resulting platform has finally been challenged to the detection of the SARS-CoV-2 ORF1ab gene sequence as the target model by measuring fluorescence before and after the hybridization event with a detection limit of 19.7fM. Furthermore, due to high sensitivity of the proposed methodology, it has been applied to directly detect the virus in nasopharyngeal samples of infected patients without the need of any amplification step. The developed bioassay has a wide range of applicability since it can be applied to the detection of any pathogen by changing the probe corresponding to the target sequence. Thus, a novel, hands-on strategy for rapid pathogen detection has proposed and has a high potential application value in the early diagnosis of infections causes by virus or bacteria.

Detection of pathogens from venous or arterial blood of patients with left-sided infective endocarditis by metagenomic next-generation sequencing: A prospective study

BackgroundInfective endocarditis is a life-threatening uncommon infectious disease, and we aimed to explore the clinical utility of venous or arterial blood-based metagenomic next-generation sequencing (mNGS) approaches to diagnose left-sided infective endocarditis (LSIE). MethodsWe prospectively studied 79 LSIE patients who received valvular surgery in our hospital. Results of blood culture, valve culture, venous blood-based mNGS, arterial blood-based mNGS, venous blood-based mNGS plus blood culture, and arterial blood-based mNGS plus blood culture were evaluated and compared. ResultsBoth venous blood- and arterial blood-based mNGS methods displayed significantly higher positive detection rates than blood culture and valve culture (43.0 %, 49.4 % vs. 32.9 %, 19.0 %; P < 0.001). Strikingly, when combining blood-based mNGS and blood culture, the positive rate could be further improved to more than 60 %. Moreover, we found mNGS LSIE detection was closely associated with preoperative leukocyte (P = 0.027), neutrophil value (P = 0.018), vegetation ≥ 14 mm (P = 0.043), and vegetations in aortic valve (P = 0.048). In addition, we discovered that blood-based mNGS had a superir capacity over blood culture to detect gram-negative bacteria, fungi, Bartonella Quintana, and mixed infections than blood culture. ConclusionThis study indicates that venous blood- and arterial blood-based mNGS displayed high positive rate in the rapid detection of pathogens in high-risk LSIE patients.

Establishment and application of a multiplex real-time PCR assay coupled with propidium monoazide for the simultaneous detection of viable Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio alginolyticus

A propidium monoazide (PMA) - multiplex real-time PCR (mRT-PCR) assay was established for the simultaneous detection of viable Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio alginolyticus. According to the unique sequences of the target genes identified by our laboratory for the above pathogenic bacteria, an efficient and specific mRT-PCR method based on TaqMan probes was developed, and then PMA was introduced into the mRT-PCR system. The optimization of the PMA treatment conditions successfully achieves the purpose of distinguishing viable and dead bacteria in the cell suspension, and effectively eliminates false positive results caused by dead cells. The method's specificity was verified by 54 strains, exhibiting 100% specificity without cross-reactivity with other pathogens. Furthermore, the developed method could accurately detect the target bacteria in the presence of non-target bacteria at a concentration range of 100-107 CFU/mL, demonstrating excellent anti-interference ability. The detection limits of V. parahaemolyticus, V. vulnificus, and V. alginolyticus were 2.0 × 101 CFU/mL, 3.2 × 101 CFU/mL, and 3.75 × 101 CFU/mL, respectively. To reflect the practicability of the method, the established method was developed as a detection kit, and the evaluation results showed that the kit has good stability and good reproducibility. The applicability of this kit was satisfying after evaluating in artificially spiked aquatic products (shrimp, yellow croakers and oysters) with recoveries ranging from 90.22% to 109.35%. The PMA-mRT-PCR detection assay is a feasible method for the rapid, sensitive, and quantitative detection of bacterial pathogens. And the novel kit developed based on this method has significant application value for the large-scale screening and identification of harmful Vibrios in food matrices.

On-site monitoring of Escherichia coli O157:H7 in drinking water based on rapid detection of the rfbE gene at the single copy level

The sensitive and on-site detection of highly pathogenic Escherichia coli O157:H7 (E. coli O157:H7) is of great importance to ensure public health. However, conventional methods for E. coli O157:H7 detection may suffer disadvantages such as high expense and time consumption. Herein, we reported a cost-effective colorimetric platform based on loop-mediated isothermal amplification (LAMP) for ultrasensitive and rapid detection of E. coli O157:H7. In this study, a novel quantitative colorimetric LAMP assay was established by in-situ measurement of hydroxy naphthol blue (HNB) color change with a designed portable device, which was applied to the amplification of the specific rfbE gene of E. coli O157:H7. As expected, this method featured a wide linear range (100-104 copies µL−1) with excellent linear regression analysis (R2 > 0.99) and possessed a record-low detection limit of 1 copy µL−1 to lower the risk of missed detection. The proposed strategy could be employed on drinking water samples with favorable recoveries and also demonstrated potential in the analysis of complex samples. This work exhibits the promising application prospect in on-site detection without the need for expensive instrumentation and seeks to provide an original paradigm for the rapid and sensitive detection of waterborne pathogens.

Rapid and sensitive detection of two fungal pathogens in soybeans using the recombinase polymerase amplification/CRISPR-Cas12a method for potential on-site disease diagnosis.

Diaporthe aspalathi and Diaporthe caulivora are two of the fungal pathogens causing soybean stem canker (SSC) in soybean, which is one of the most widespread diseases in soybean growing regions and can cause 100% loss of yield. Current methods for the detection of fungal pathogens, including morphological identification and molecular detection, are mostly limited by the need for professional laboratories and staff. To develop a detection method for potential on-site diagnosis for two of the fungal pathogens causing SSC, we designed a rapid assay combining recombinase polymerase amplification (RPA) and CRISPR-Cas12a-based diagnostics to specifically detect D. aspalathi and D. caulivora. The translation elongation factor 1-alpha gene was employed as the target gene to evaluate the specificity and sensitivity of this assay. The RPA/CRISPR-Cas12a system has excellent specificity to distinguish D. aspalathi and D. caulivora from closely related species. The sensitivities of RPA/CRISPR-Cas12a-based fluorescence detection and lateral flow assay for D. aspalathi and D. caulivora are 14.5 copies and 24.6 copies, respectively. This assay can detect hyphae in inoculated soybean stems at 12 days after inoculation and has a recovery as high as 86% for hyphae-spiked soybean seed powder. The total time from DNA extraction to detection was not more than 60 min. The method developed for rapid detection of plant pathogens includes DNA extraction with magnetic beads or rapid DNA extraction, isothermal nucleic acid amplification at 39 °C, CRISPR-Cas12a cleavage reaction at 37 °C, and lateral flow assay or endpoint fluorescence visualization at room temperature. The RPA and CRISPR-Cas12a reagents can be preloaded in the microcentrifuge tube to simplify the procedures in the field. Both RPA and CRISPR-Cas12a reaction can be realized on a portable incubator, and the results are visualized using lateral flow strips or portable flashlight. This method requires minimal equipment and operator training, and has promising applications for rapid on-site disease screening, port inspection, or controlling fungal pathogen transmission in crop. © 2023 Society of Chemical Industry.

Rapid detection of pathogens of peritoneal dialysis-related peritonitis, especially in patients who have taken antibiotics, using metagenomic next-generation sequencing: a pilot study

Introduction Peritoneal dialysis (PD)-related peritonitis is a serious complication of PD. Improving the diagnostic rate of peritonitis pathogens may substantially benefit peritonitis patients. Methods The study was conducted in the People’s Liberation Army (PLA) General Hospital from 1 June 2021 to 31 May 2022. Information about peritonitis, culture and metagenomic next-generation sequencing (mNGS) results and so on were collected. Patients were divided into antibiotic-use and antibiotic-free groups. The culture and mNGS results were compared using the paired χ2 test. Results Data from 26 patients with peritonitis were collected. 50% of the patients had used antibiotics before samples were obtained (antibiotic-use group). The positivity rate using culture was 92.3% (12 cases) in the antibiotic-free group and 38.5% (5 cases) in the antibiotic-use group (p = 0.011). However, the positivity rate using mNGS was 92.3% (12 cases) regardless of whether antibiotics were used (p = 1.000). After revising the mNGS results, the positivity rate was 84.6% (11 cases) in both groups (p = 1.000). A significant difference between culture and mNGS results of all groups was observed (p = 0.039). The difference no matter between culture and mNGS (p = 0.016) or between culture and modified mNGS (p = 0.031) of the antibiotic-use group was observed. Conclusion For patients with PD-related peritonitis who previously received antibiotics, mNGS is suggested. For other patients, mNGS testing can be performed, but the results should be interpreted with caution. Much more research should be done to identify a powerful and ideal tool to detect pathogens underlying PD-related peritonitis.

A convenient electrochemical biosensor mediated by filtration-assisted pretreatment and multi-TEs amplification system for Staphylococcus aureus detection in complex matrices

Rapid detection of foodborne pathogens plays a more and more significant role in the field of public health. In this research, we developed a convenient electrochemical biosensor mediated by filtration-assisted pretreatment and multiple thermostatic enzymes (Multi-TEs) amplification system for the detection of Staphylococcus aureus (S. aureus) in complex matrices. Firstly, the designed filtration-assisted pretreatment could simultaneously collect and enrich target bacterium from various actual samples within 5 min. Then, the target bacterial genome template was reacted at 37 °C in Multi-TEs amplification system to obtain specific double stranded products. Finally, the specific double stranded products were fixed on the surface of the electrode and the electrochemical indicators (Methylene blue, MB) was combined for the quantitative one-step electrochemical analysis of S. aureus. This assay has great linear calibration curves with the concentration ranging from 101 CFU/mL to 106 CFU/mL. The limit of detections (LOD) was defined as 1.28 CFU/mL, which performance is superior to some commercial ELISA kits. Meanwhile, amazingly, it has excellent specificity for S. aureus against other foodborne pathogens and could be applied for S. aureus analysis in human serum samples with the great recoveries and associated relative standard deviations (RSDs). These features do make the ideal facile electrochemical analytical platform for on-site detection of S. aureus.

Performance and Impact on Antibiotic Prescriptions of a Multiplex PCR in a Real-Life Cohort of Critically Ill Patients with Suspected Ventilated Pneumonia: A Retrospective Monocentric Observational Study.

Pulmonary multiplex polymerase chain reaction (m-PCR) allows rapid pathogen detection. We aimed to assess its impact on initial antibiotic prescriptions in ventilated patients with suspected pneumonia. Between November 2020 and March 2022,ventilated patients with suspected pneumonia hospitalized in our ICU who benefited from respiratory sampling simultaneously tested using conventional microbiological methods and m-PCR were included. The proportion of appropriate changes in the initial antibiotic therapy following m-PCR results was assessed. We analyzed 104 clinical samples. Of the 47 negative m-PCR results, 16 (34%) led to an appropriate antibiotic strategy: 8 cessationsand 8 lack of initiation. Of the 57 positive m-PCR results, 51 (89%) resulted in an appropriate antibiotic strategy: 33 initiations, 2 optimizations, and 9 de-escalations. In the multivariate analysis, a positive m-PCR was associated with an appropriate antibiotic change (OR: 96.60; IC95% [9.72; 960.20], p < 0.001). A higher SAPS II score was negatively associated with an appropriate antibiotic change (OR: 0.96; IC95% [0.931; 0.997], p = 0.034). In our cohort, a positive m-PCR allowed for early initiation or adjustment of antibiotic therapy in almost 90% of cases. A negative m-PCR spared antibiotic use in onethird of cases. The impact of m-PCR results was reduced in the most severe patients.

Development of an LFD-RPA Assay for Rapid Detection of Pentatrichomonas hominis Infection in Dogs.

Pentatrichomonas hominis is a trichomonad protozoan that infects the cecum and colon of humans and other mammals. It is a zoonotic pathogen that causes diarrhea in both animals and humans. As companion animals, dogs infected with P. hominis pose a risk of transmitting it to humans. Current methods, such as direct smears and polymerase chain reaction (PCR), used for P. hominis detection have limitations, including low detection rates and the need for specialized equipment. Therefore, there is an urgent need to develop rapid, sensitive, and simple detection methods for clinical application. Recombinase polymerase amplification (RPA) has emerged as a technology for rapid pathogen detection. In this study, we developed a lateral flow dipstick (LFD)-RPA method based on the highly conserved SPO11-1 gene for detecting P. hominis infection by optimizing the primers, probes, and reaction conditions, and evaluating cross-reactivity with genomes of Giardia duodenalis and other parasites. The LFD-RPA method was then used to test 128 dog fecal samples collected from Changchun. The results confirmed the high specificity of the method with no cross-reactivity with the five other parasites. The lowest detection limit of the method was 102 copies/µL, and its sensitivity was 100 times higher than that of the conventional PCR method. Consistent with the positivity rate observed using nested PCR, 12 samples (out of 128) tested positive using this method (positivity rate, 9.38%). In conclusion, the LFD-RPA method developed in this study represents a simple and sensitive assay that allows for the rapid detection of P. hominis infection in dogs, especially in this field.

Simple and Multiplexed Detection of Nucleic Acid Targets Based on Fluorescent Ring Patterns and Deep Learning Analysis.

Simple diagnostic tests for nucleic acid targets can provide great advantages for applications such as rapid pathogen detection. Here, we developed a membrane assay for multiplexed detection of nucleic acid targets based on the visualization of two-dimensional fluorescent ring patterns. A droplet of the assay solution is applied to a cellulose nitrate membrane, and upon radial chromatographic flow and evaporation of the solvent, fluorescent patterns appear under UV irradiation. The target nucleic acid is isothermally amplified and is immediately hybridized with fluorescent oligonucleotide probes in a one-pot reaction. We established the fluorescent ring assay integrated with isothermal amplification (iFluor-RFA = isothermal fluorescent ring-based radial flow assay), and feasibility was tested using nucleic acid targets of the receptor binding domain (RBD) and RNA-dependent RNA polymerase (RdRp) genes of SARS-CoV-2. We demonstrate that the iFluor-RFA method is capable of specific and sensitive detection in the subpicomole range, as well as multiplexed detection even in complex solutions. Furthermore, we applied deep learning analysis of the fluorescence images, showing that patterns could be classified as positive or negative and that quantitative amounts of the target could be predicted. The current technique, which is a membrane pattern-based nucleic acid assay combined with deep learning analysis, provides a novel approach in diagnostic platform development that can be versatilely applied for the rapid detection of infectious pathogens.

E. coli O157:H7 Detection Using Surface Plasmon Resonance Based Biosensor

The detection of foodborne pathogenic bacteria remains a significant challenge, and the need for fast and sensitive detection methods is becoming increasingly important. Escherichia coli is a prevalent bacteria associated with foodborne illness, and this study aimed to evaluate the ability of a surface plasmon resonance (SPR) based biosensor to detect E. coli O157:H7 at low levels in pure culture and artificially contaminated bay leaves (Laurus nobilis) using different injection methods. To develop a biological sensing surface, the sensor surface was functionalized with 3-aminopropyltriethoxysilane (APTES), and polyclonal antibodies were immobilized on the surface for bacteria detection. Bacterial attachment to the antibodies resulted in a change in resonance angle. The biosensor was able to discriminate between cellular concentrations of 103 to 107 CFU/mL and showed potential in detecting different pathogens in various food samples. Before the SPR detection, the sample preparation step was optimized to ensure complex food matrices were suitable for SPR analysis. The results suggest that the SPR based biosensor is a promising tool for the rapid detection of foodborne pathogens in complex food matrices.

QIAstat-Dx gastrointestinal panel and Luminex xTAG gastrointestinal pathogen panel comparative evaluation.

The diagnosis of acute gastroenteritis is an ongoing clinical challenge in terms of identification of the etiologic agent, time to results, and appropriate treatment. Rapid detection of gastrointestinal pathogens is needed to improve patient care. This study evaluates the performance of the QIAstat-Dx gastrointestinal panel (Q-GP; Investigational Use Only) compared to the Luminex xTAG gastrointestinal pathogen panel (L-GPP; US-IVD). Using 245 stool specimens, we evaluated 10 different targets including rotavirus, norovirus, Salmonella, Shigella, Campylobacter, Giardia, Cryptosporidium, Escherichia coli O157, enterotoxigenic E. coli (ETEC), and Shiga toxin-producing E. coli (STEC). For the viral targets, the percent positive agreement (PPA) for rotavirus was 100% (n = 19) and that for norovirus was 91% (20/22). For the parasitic targets, the PPA was 100% for Giardia and Cryptosporidium (n = 18 and n = 23, respectively). The PPA was 96% for Salmonella (22/23) and Campylobacter (22/23), and the PPA for Shigella was 100% (n = 23). For the E. coli targets, a PPA of 94% was achieved for STEC (32/34) and 96% for ETEC (24/25). We did not assess PPA for the E. coli O157 target as the Q-GP O157 call is stx dependent. The negative percent agreement across all targets was 99.1%. Our study suggests that QIAstat-Dx GP provides comparable results to Luminex GPP based on the analysis of targets found on both panels.

Optical Spectroscopy Based Microfluidic Platform for Detecting Pathogens Using Immunomagnetic Separation

Rapid detection of pathogens is crucial for controlling pathogenic diseases and improving the quality of food industry. This paper presents a microfluidic platform integrated with optical detection module to rapidly detect Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli). The detection module comprises a microfluidic chip embedded with fiber optics connected to photosensors and a laser source. Initially, the immunomagnetic separation technique was applied to isolate specific pathogens out of testing sample using magnetic particles coated with antibodies. The separated sample containing magnetic beads was loaded into the chip and passed by the monochromatic light in the detection module. The scattered light signals from the passing magnetic beads were collected by the photosensors coupled with fiber optics. The acquired raw data were pre-processed by removing noise and distortions for further analysis. A new calibration model known as the Optical Transformer (OptiTr) structure was used for classification of acquired data. Convolution-based classical model (ResNeXt) was used as baseline comparison. The system provided higher classification results using the OptiTr model for classifying P. aeruginosa and E. coli, with accuracy values of 99.57% and 94.59%, respectively. The blank samples without P. aeruginosa and E. coli showed a classification accuracy of 94.73%. The microfluidic platform has the capability to identify P. aeruginosa and E. coli with a detection limit of 101 CFU/mL. The technique does not require complex sample preparation methods or complicated laboratory tools. The developed technique has a 15-minute detection time with a 40-minute sample preparation duration.

How I approach diarrhea in hematological transplant patients: A practical tool.

Diarrhea in hematopoietic stem-cell transplantation (HSCT) remains a multifactorial challenge that demands a nuanced diagnostic approach. The causes of infectious diarrhea in HSCT recipients are diverse and influenced by patient-specific risk factors, the post-transplant timeline, and local epidemiology. During the past decade, our understanding of diarrhea in HSCT has witnessed a transformative shift through the incorporation of gastrointestinal (GI) multiplex polymerase chain reaction (PCR) panels. However, the judicious application of these panels is imperative to avoid overtesting and prevent adverse outcomes. The challenge lies in distinguishing between the diverse causes of diarrhea, ascertaining the clinical significance of detected pathogens, and navigating the diagnostic uncertainty presented by several non-infectious conditions such as mucositis, intestinal dysbiosis, and acute graft-versus-host disease (aGvHD), all of which mimic infection. This review examines the landscape of infectious diarrhea in the HSCT population, encompassing both established (e.g., Cytomegalovirus, Clostridioides difficile, and norovirus) and emerging pathogens (e.g., sapoviruses, astroviruses). We propose a multifaceted diagnostic algorithm that combines clinical assessment, risk stratification, and tailored utilization of molecular platforms. While multiplex GI panels present invaluable opportunities for rapid and comprehensive pathogen detection, their judicious use is pivotal in preserving diagnostic stewardship. Customization of diagnostic algorithms tailored to local epidemiology ensures optimal patient care and resource utilization.

Capture antibody imitator MnO2 nanozyme-based dual-signal immunochromatographic assay for rapid detection of Salmonella enteritidis

The sensitive and rapid detection of foodborne pathogens is of great significance to global public health security. Here, with two-dimensional nanomaterial MnO2 NSs as the capture antibody imitator and signal reporter molecules, based on its enzyme-catalyzed signal amplification capability, a label-free, dual-signal output immunochromatographic biosensor was constructed to achieve the sensitive detection of S. enteritidis. The capture antibody imitator of MnO2 capture probe shows an outstanding capture ability, forming a stable immune complex with S. enteritidis. As an in-situ catalytic amplification colorimetric signal trigger, MnO2 NSs exert oxidase-like enzyme activity and obtain satisfactory detection sensitivity. It is worth noting that the proposed dual-signal ICA has high analytical performances for S. enteritidis during the concentration range of 103-107 cfu mL−1 both in standard bacterial solutions and food matrixes.