Search

The global proliferation of carbapenemase-producing bacteria (CPB) has garnered significant attention worldwide. Early diagnosis of CPB and accurate identification of carbapenemases are crucial for preventing the spread of CPB and ensuring targeted antibiotic therapy. Therefore, efficient and accurate identification of carbapenemases is paramount in clinically treating diseases associated with CPB. In this study, 58 CPB strains were collected and detected using the DNA endonuclease-targeted CRISPR trans reporter (DETECTR) method, a rapid detection platform based on CRISPR-Cas12a gene editing and isothermal amplification. Additionally, four conventional methods (the APB/EDTA method, PCR, NG-test Carba 5, and GeneXpert Carba-R) were employed and compared against whole genome sequencing (WGS) results, considered the gold standard, to evaluate their efficacy in detecting carbapenemases. Detection by the APB/EDTA method revealed that 29 strains were positive for Class A serine endopeptidases, while 29 strains were positive for Class B metalloenzymes. The classification of these zymotypes was consistent with the sequencing result. All target carbapenemases for KPC were identified with 100% sensitivity using NG-test Carba 5, PCR, DETECTR, and GeneXpert Carba-R. In the case of NDM, both Xpert Carba-R and DETECTR showed a sensitivity of 100%. In contrast, NG-test Carba 5 and PCR had a slightly lower sensitivity of 96.7%, each missing one target carbapenemase. n this study, the APB/EDTA method is capable of identifying the zymotype classification but not the specific resistant genes, while Xpert Carba-R and DETECTR are able to detect all target carbapenemases. [ABSTRACT FROM AUTHOR]

Introduction: As the last line of defense for clinical treatment, Carbapenem antibiotics are increasingly challenged by multi-drug resistant bacteria containing carbapenemases. The rapid spread of these multidrug-resistant bacteria is the greatest threat to severe global health problems. Methods: To solve the problem of rapid transmission of this multidrug-resistant bacteria, we have developed a rapid detection technology using CRPSPR-Cas12a gene editing based on multiple Recombinase polymerase amplification. This technical method can directly isolate the genes of carbapenemase-containing bacteria from samples, with a relatively short detection time of 30 minutes. The instrument used for the detection is relatively inexpensive. Only a water bath can complete the entire experiment of Recombinase polymerase amplification and trans cleavage. This reaction requires no lid during the entire process while reducing a large amount of aerosol pollution. Results: The detection sensitivity of this method is 1.5 CFU/mL, and the specificity is 100%. Discussion: This multi-scene detection method is suitable for screening populations in wild low-resource environments and large-scale indoor crowds. It can be widely used in hospital infection control and prevention and to provide theoretical insights for clinical diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Norovirus is highly infectious and rapidly transmissible and represents a major pathogen of sporadic cases and outbreaks of acute gastroenteritis worldwide, causing a substantial disease burden. Recent years have witnessed a dramatic increase in norovirus outbreaks in China, significantly higher than in previous years, among which GII norovirus is the predominant prevalent strain. Therefore, rapid norovirus diagnosis is critical for clinical treatment and transmission control. Hence, we developed a molecular assay based on RPA combined with the CRISPER-CAS12a technique targeting the conserved region of the GII norovirus genome, the results of which could be displayed by fluorescence curves and immunochromatographic lateral-flow test strips. The reaction only required approximately 50 min, and the results were visible by the naked eye with a sensitivity reaching 102 copies/μl. Also, our method does not cross-react with other common pathogens that cause intestinal diarrhea. Furthermore, this assay was easy to perform and inexpensive, which could be widely applied for detecting norovirus in settings including medical institutions at all levels, particularly township health centers in low-resource areas. [ABSTRACT FROM AUTHOR]

The widespread dissemination of coronavirus 2019 imposes a significant burden on society. Therefore, rapid detection facilitates the reduction of transmission risk. In this study, we proposed a multiplex diagnostic platform for the rapid, ultrasensitive, visual, and simultaneous detection of the severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) open reading frame 1ab (ORF1ab) and N genes. A visual diagnostic method was developed using a clustered regularly interspaced short palindromic repeat (CRISPR)‐Cas12a/Cas13a dual‐enzyme digestion system integrated with multiplex reverse transcriptase‐recombinase polymerase amplification (RT‐RPA). Two CRISPR‐Cas proteins (Cas12a and Cas13a) were introduced into the system to recognize and cleave the N gene and ORF1ab gene, respectively. We used fluorescent or CRISPR double digestion test strips to detect the digested products, with the N gene corresponding to the FAM channel in the PCR instrument or the T1 line on the test strip, and the ORF1ab gene corresponding to the ROX channel in the PCR instrument or the T2 line on the test strip. The analysis can be completed in less than 20 min. Meanwhile, we assessed the application of the platform and determined a sensitivity of up to 200 copies/mL. Additionally, dual gene validation in 105 clinical nasopharyngeal swab samples showed a 100% positive predictive value agreement and a 95.7% negative predictive value agreement between our method and quantitative reverse transcription‐polymerase chain reaction. Overall, our method offered a novel insight into the rapid diagnosis of SARS‐CoV‐2. [ABSTRACT FROM AUTHOR]

The recent major worldwide outbreak of monkeypox virus (MPXV) has highlighted the urgent need for accurate MPXV detection methods. Although quantitative PCR (qPCR) technique is currently the gold standard for MPXV diagnosis, the high costs associated with the technique and the need for complex instrumentation, limits its application in resource‐poor settings. CRISPR technology has developed rapidly in recent years and provides an effective tool for point‐of‐care testing pathogen identification. Here, we exploited the cleavage properties of the Cas12a enzyme and Cas13a enzyme, to detect the MPXV specific genes, F3L gene and B6R gene, respectively. We developed two detection protocols: a 2‐step method in which the CRISPR Dual System reaction and the multiplex recombinase polymerase amplification reaction were carried out in separate tubes and a single‐tube method in which both reactions were carried out in one tube. Evaluation of the two methods showed that our protocol can detect the MPXV genome down to 10° copies/μL with good specificity and no cross‐reactivity with other poxviruses pseudoviruses, and bacteria. Mock positive samples were used to assess clinical applicability, with the results showing satisfactory concordance with the qPCR method for parallel testing. In conclusion, our study provides a reliable molecular diagnostic strategy for detection of MPXV. [ABSTRACT FROM AUTHOR]

Introduction: More than half of the world's people are infected or have been infected with Helicobacter pylori. This infection is related to many diseases, with its pathogenicity related to virulence factors. Therefore, the rapid diagnosis of H. pylori and genotyping of virulence genes play an extremely important role in the clinical treatment and control of transmission. Methods: To this end, we developed a molecular detection method based on RPA- CRISPR-Cas12a technology for the specific genes 16S rDNA gene, cytotoxin associated gene A(cagA), and vacuolating cytotoxin A (vacA) of H. pylori. Results: The results of which were displayed by lateral flow strips. Macroscopic observation takes only about 25 minutes and the sensitivity is 2ng/microliter. Discussion: The method is simple, convenient to operate and has low costs, and can therefore be applied widely to the detection and typing of H. pylori in various environments such as primary hospitals, community clinics, outdoors, and large medical institutions. [ABSTRACT FROM AUTHOR]

Introduction: Carbapenemase-mediated antimicrobial resistance is currently a hot spot of global concern. Carbapenem-resistant organisms are highly prevalent in hospitals associated with difficult-to-treat infections, resulting in poor clinical outcome due to limited treatment options. It is urgently needed to have a rapid, efficient, and convenient molecular assay for identifying such resistant strains. Methods: For this end, we developed a new laboratory assay targeting Klebsiella pneumoniae carbapenemase (KPC) and New Delhi metallo-β-lactamase (NDM) based on loop-mediated isothermal amplification, CRISPR–Cas12a, and lateral flow immunochromatographic strip (CRISPR–Cas-LAMP-lateral flow strip). The method was designed to use a guide RNA (gRNA) to recognize the target DNA and guide Cas12a to cleave the target DNA, and simultaneously cleave any single-stranded DNA within the cleavage reaction system. Results: The cleavage products are visible to the naked eye on the lateral flow strip. This method is highly sensitive in direct detection of bacteria in samples containing at least 3× 105 CFU/mL without the need for bacterial culture. Discussion: It provides shorter turnaround time and higher specificity than the conventional bacterial culture and susceptibility testing method. This new assay is applicable for extensive use in hospital infection control, as well as identification and treatment of resistant strains due to simple operation and inexpensive apparatuses. [ABSTRACT FROM AUTHOR]

The opportunistic pathogens causing Cryptococcal meningitis are Cryptococcus neoformans and Cryptococcus gattii species complexes. At present, clinical detection methods for this condition include culture, ink staining, and cryptococcal antigen detection. In addition, enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), and real-time quantitative PCR (qPCR) can be applied for the detection of Cryptococcus. Nevertheless, these methods cannot achieve point-of-care detection (POCT); thus, there is a pressing need to establish a fast, sensitive, and effective detection method. Recombinase polymerase amplification (RPA) and clustered regularly spaced short palindromic repeat (CRISPR) techniques are effective tools for achieving rapid POCT. In this study, RPA was combined with CRISPR-Cas12a to establish a fast, sensitive, and specific detection method for cryptococcal meningitis. This study included RPA-Cas12a fluorescence detection and RPA-Cas12a immunochromatographic detection, which can be performed within 50 min. Moreover, the detection limit was as low as 102 copies/μL. Interestingly, the developed method demonstrated satisfactory specificity and no cross-reactivity with other fungi and bacteria. 36 clinical samples were tested, and the consistency between the test results and those obtained using the commonly used clinical culture method was 100 %. In this study, a rapid detection method for Cryptococcus neoformans and Cryptococcus gattii species complexes was developed based on CRISPR-Cas12a technology, characterized by its high sensitivity and specificity, ease of use, and cost-effectiveness, making it suitable for on-site detection. • Developed CRISPR-Cas12a method for C. neoformans / C. gattii POCT. • The method is highly specific and sensitive. • This method replaces traditional cerebrospinal fluid pathogen detection. [ABSTRACT FROM AUTHOR]

• The RPA-CRISPR-Cas12a diagnostic platform for the diagnosis of Mycoplasma pneumoniae. • It has been validated that RPA-CRISPR/Cas12a fluorescence analysis and RPA-CRISPR/Cas12a-immunochromatographic exhibit no cross-reactivity with other common pathogens, and The established detection limit was ascertained to be as low as 102 copies/µL. • The RPA-CRISPR-Cas12a provides results within 40 min for on-site detection. Mycoplasma pneumoniae can cause respiratory infections and pneumonia, posing a serious threat to the health of children and adolescents. Early diagnosis of Mycoplasma pneumoniae infection is crucial for clinical treatment. Currently, diagnostic methods for Mycoplasma pneumoniae infection include pathogen detection, molecular biology techniques, and bacterial culture, all of which have certain limitations. Here, we developed a rapid, simple, and accurate detection method for Mycoplasma pneumoniae that does not rely on large equipment or complex operations. This technology combines the CRISPR-Cas12a system with recombinase polymerase amplification (RPA), allowing the detection results to be observed through fluorescence curves and immunochromatographic lateral flow strips.It has been validated that RPA-CRISPR/Cas12a fluorescence analysis and RPA-CRISPR/Cas12-immunochromatographic exhibit no cross-reactivity with other common pathogens, and The established detection limit was ascertained to be as low as 102 copies/µL.Additionally, 49 clinical samples were tested and compared with fluorescence quantitative polymerase chain reaction, demonstrating a sensitivity and specificity of 100%. This platform exhibits promising clinical performance and holds significant potential for clinical application, particularly in settings with limited resources, such as clinical care points or resource-constrained areas. [ABSTRACT FROM AUTHOR]