scholarly journals Bioprocessing and integration of a high flux screening systematic platform based on isothermal amplification for the detection on 8 common pathogens

Author(s):  
Huamin Zhong ◽  
Hongwei Deng ◽  
Ming Li ◽  
Huahong Zhong

Abstract During a large variety of common pathogens, E. coli, P. aeruginosa, MRSA, MRCNS, V. parahaemolyticus, L. monocytogenes and Salmonella are the leading pathogens responsible for large number of human infections and diseases. In this study, a high flux screening based on nucleic acid isothermal amplification technique has been developed. For the 8 common pathogens, species-specific targets had been selected and analyzed for their unique specificity. After optimization, separate LAMP reaction assays had been bioprocessed and integrated into one systematic detection platform, including 8 strips (PCR tubes) and 96-well plates. Eight standard strains verified for the accuracy. Application of the established high flux screening platform was used for detection for 48 samples in 4 different 96-well plates, with 2 groups of 2 operators using double-blind procedure. The accuracy of 100% was obtained, with the total time consumption as 66–75 min (for 12 samples detection on 8 different pathogens). As concluded, through the bioprocess of the systematic platform based on LAMP technique, it’s been demonstrated to be capable of simultaneous detection of 8 pathogens, with high sensitivity, specificity, rapidity and convenience.

1999 ◽  
Vol 18 (4) ◽  
pp. 227-233 ◽  
Author(s):  
Alexander Schütz ◽  
Andrea Tannapfel ◽  
Christian Wittekind

Most of the double immunostaining protocols that have been introduced so far have been developed for application on fresh frozen material or based on different species antibodies. In liver tissue, general problems of double immunostaining techniques are further complicated by tissue‐specific difficulties, such as necrosis or high intracellular protein content. To assess a reliable double immunostaining protocol for archived, paraffin embedded liver tissue, different protocols based on the use of same species primary antibodies were evaluated in terms of sensitivity, specificity and non‐specific background staining in pathological liver specimens. We compared peroxidase–anti‐peroxidase, alkaline phosphatase–anti‐alkaline phosphatase (PAP/APAP), labelled‐avidin–biotin (LAB/LAB) and digoxigenin–anti‐digoxigenin (dig–a‐dig/PAP) techniques using different cytokeratin antibodies and an antibody against PCNA. Comparison of the double immunostaining techniques revealed a high sensitivity and specificity in all procedures. Sections, which were stained employing PAP/APAP‐technique, displayed a higher background staining compared to sections which were treated with the LAB/LAB or dig–a‐dig/PAP protocol. In contrast to the dig–a‐dig/PAP protocol, the LAB/LAB technique provides a better time/cost relationship. Therefore, we would like to recommend a modified LAB/LAB protocol for simultaneous detection of different antigens in archived liver tissue.


PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254029
Author(s):  
Thanawat Sridapan ◽  
Wanida Tangkawsakul ◽  
Tavan Janvilisri ◽  
Taradon Luangtongkum ◽  
Wansika Kiatpathomchai ◽  
...  

Development of a simple, rapid and specific assay for the simultaneous detection of Campylobacter spp. and Salmonella spp. based on duplex loop-mediated isothermal amplification (d-LAMP), combined with lateral-flow biosensor (LFB) is reported herein. LAMP amplicons of both pathogens were simultaneously amplified and specifically differentiated by LFB. The specificity of the d-LAMP-LFB was evaluated using a set of 68 target and 12 non-target strains, showing 100% inclusivity and exclusivity. The assay can simultaneously detect Campylobacter and Salmonella strains as low as 1 ng and 100 pg genomic DNA per reaction, respectively. The lowest inoculated detection limits for Campylobacter and Salmonella species in artificially contaminated chicken meat samples were 103 CFU and 1 CFU per 25 grams, respectively, after enrichment for 24 h. Furthermore, compared to culture-based methods using field chicken meat samples, the sensitivity, specificity and accuracy of d-LAMP- LFB were 95.6% (95% CI, 78.0%-99.8%), 71.4% (95% CI, 29.0%-96.3%) and 90.0% (95% CI, 73.4%-97.8%), respectively. The developed d-LAMP-LFB assay herein shows great potentials for the simultaneous detection of the Campylobacter and Salmonella spp. and poses a promising alternative approach for detection of both pathogens with applications in food products.


Author(s):  
Seyedeh Zahra Alamolhoda ◽  
Nosratollah Zarghami ◽  
Houman Kahroba ◽  
Ahmad Mehdipour ◽  
Mohammad Pourhassan-Moghaddam ◽  
...  

Antibiotic resistance is one of the serious health-threatening issues globally, the control of which is indispensable for rapid diagnosis and treatment because of the high prevalence and risks of pathogenicity. Traditional and molecular techniques are relatively expensive, complex, and non-portable, requiring facilities, trained personnel, and high-tech laboratories. Widespread and timely-detection is vital to the better crisis management of rapidly spreading infective diseases, especially in low-tech regions and resource-limited settings. Hence, the need for inexpensive, fast, simple, mobile, and accessible point-of-care (POC) diagnostics is highly demanding. Among different biosensing methods, the isothermal amplification of nucleic acids is favorite due to their simplicity, high sensitivity/specificity, rapidity, and portability, all because they require a constant temperature to work. Isothermal amplification methods are utilized for detecting various targets, including DNA, RNA, cells, proteins, small molecules, ions, and viruses. In this paper, we discuss various platforms, applications, and potentials of isothermal amplification techniques for biosensing of antimicrobial resistance. We also evaluate the potential of these methods, coupled with the novel and rapidly-evolving platforms offered by nanotechnology and microfluidic devices.


2015 ◽  
Vol 22 (4) ◽  
pp. 374-380 ◽  
Author(s):  
Ian E. Burbulis ◽  
Kumiko Yamaguchi ◽  
Olga V. Nikolskaia ◽  
Sean T. Prigge ◽  
Stefan Magez ◽  
...  

ABSTRACTLoop-mediated isothermal amplification (LAMP) is a method for enzymatically replicating DNA that has great utility for clinical diagnosis at the point of care (POC), given its high sensitivity, specificity, speed, and technical requirements (isothermal conditions). Here, we adapted LAMP for measuring protein analytes by creating a protein-DNA fusion (referred to here as a “LAMPole”) that attaches oligonucleotides (LAMP templates) to IgG antibodies. This fusion consists of a DNA element covalently bonded to an IgG-binding polypeptide (protein L/G domain). In our platform, LAMP is expected to provide the most suitable means for amplifying LAMPoles for clinical diagnosis at the POC, while quantitative PCR is more suitable for laboratory-based quantification of antigen-specific IgG abundance. As proof of concept, we measured serological responses to a protozoan parasite by quantifying changes in solution turbidity in real time. We observed a >6-log fold difference in signal between sera from vaccinated versus control mice and in a clinical patient sample versus a control. We assert that LAMPoles will be useful for increasing the sensitivity of measuring proteins, whether it be in a clinical laboratory or in a field setting, thereby improving acute diagnosis of a variety of infections.


2021 ◽  
Vol 10 (6) ◽  
pp. 1308
Author(s):  
Beatriz Crego-Vicente ◽  
Pedro Fernández-Soto ◽  
Begoña Febrer-Sendra ◽  
Juan García-Bernalt Diego ◽  
Jérôme Boissier ◽  
...  

Schistosomiasis is a disease of great medical and veterinary importance in tropical and subtropical regions caused by different species of parasitic flatworms of the genus Schistosoma. The emergence of natural hybrids of schistosomes indicate the risk of possible infection to humans and their zoonotic potential, specifically for Schistosoma haematobium and S. bovis. Hybrid schistosomes have the potential to replace existing species, generate new resistances, pathologies and extending host ranges. Hybrids may also confuse the serological, molecular and parasitological diagnosis. Currently, LAMP technology based on detection of nucleic acids is used for detection of many agents, including schistosomes. Here, we evaluate our previously developed species-specific LAMP assays for S. haematobium, S. mansoni, S. bovis and also the genus-specific LAMP for the simultaneous detection of several Schistosoma species against both DNA from pure and, for the first time, S. haematobium x S. bovis hybrids. Proper operation was evaluated with DNA from hybrid schistosomes and with human urine samples artificially contaminated with parasites’ DNA. LAMP was performed with and without prior DNA extraction. The genus-specific LAMP properly amplified pure Schistosoma species and different S. haematobium-S. bovis hybrids with different sensitivity. The Schistosoma spp.-LAMP method is potentially adaptable for field diagnosis and disease surveillance in schistosomiasis endemic areas where human infections by schistosome hybrids are increasingly common.


1996 ◽  
Vol 76 (06) ◽  
pp. 1090-1095 ◽  
Author(s):  
C Ravanat ◽  
M Freund ◽  
S Schuhler ◽  
P Grunert ◽  
L Meyer ◽  
...  

SummaryThe purpose of this study was to develop specific and sensitive immunoassays to detect early indices of hypercoagulability in the rat. Rat platelet factor 4 (rPF4) and rat fibrinopeptide A (rFPA) assays, tools for the detection of activation of platelets and coagulation respectively, were designed using antibodies raised against purified rPF4 and against synthetic rFPA. The relevance of these new assays and of the commercially available ELISA kit for thrombin-antithrombin III (TAT) complexes was demonstrated in a rat model of a prethrombotic state induced by intravenous infusion of varying doses of thromboplastin (90 to 2400 μl/kg/h). In this model, the immunoassays allowed simultaneous detection of low levels of rFPA and rPF4 which were correlated with fibrinogen and platelet consumption and TAT generation and further proved to be of higher sensitivity than the classical methods of platelet count or measurement of fibrinogen levels. Plasma concentrations of rFPA, rPF4 and TAT were dependent on infusion time and thromboplastin dose, while hirudin (1 mg/kg) prevented their appearance. Thus the new specific immunoassays for rPF4 and rFPA and the commercial human TAT assay represent useful tools for pathophysiological studies or the screening of antithrombotic drugs in rats.


Author(s):  
Suraj Mathur

This prospective study was done in the Department of Radio diagnosis Govt. Medical College, Kozhikode. A total of 65 patients who were referred to our department with clinical suspicion of endometrial lesions and incidentally detected endometrial lesions on ultrasonography underwent transvaginal ultrasound and subsequent Imaging evaluation of pelvis MRI has very high sensitivity (95%) and specificity (98%) and is almost as accurate (97%) as histopathology in differentiating benign from malignant lesions. Addition of DWI with ADC mapping to conventional MRI increases its accuracy even more. However there is inherent limitation to MRI in detecting carcinoma in situ and micrometastasis. Keywords: TVS, MRI, Sensitivity, Specificity, Histopathology.


2021 ◽  
pp. 095646242110222
Author(s):  
Thomas Juniper ◽  
Chris P Eades ◽  
Eliza Gil ◽  
Harriet Fodder ◽  
Killian Quinn ◽  
...  

Objectives: An elevated serum (1-3)-β-D-glucan (BDG) concentration has high sensitivity for a diagnosis of Pneumocystis pneumonia (PCP) in people with HIV (PWH). At the current manufacturer-recommended positive threshold of 80 pg/mL (Fungitell), specificity for PCP is variable and other diagnostic tests are required. We evaluated the utility of serum BDG for diagnosis of suspected PCP in PWH at three inner-London hospitals to determine BDG concentrations for diagnosis and exclusion of PCP. Methods: From clinical case records, we abstracted demographic and clinical information and categorised patients as having confirmed or probable PCP, or an alternative diagnosis. We calculated sensitivity, specificity and positive predictive value (PPV) of serum BDG concentrations >400 pg/mL and negative predictive value (NPV) of BDG <80 pg/mL. Results: 76 patients were included; 29 had laboratory-confirmed PCP, 17 had probable PCP and 30 had an alternative diagnosis. Serum BDG >400 pg/mL had a sensitivity of 83%, specificity of 97% and PPV 97% for diagnosis of PCP; BDG <80 pg/mL had 100% NPV for exclusion of PCP. Conclusions: In PWH with suspected PCP, BDG <80 pg/mL excludes a diagnosis of PCP, whereas BDG concentrations >400 pg/mL effectively confirm the diagnosis. Values 80–400 pg/mL should prompt additional diagnostic tests.


Children ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 521
Author(s):  
Ina Nehring ◽  
Heribert Sattel ◽  
Maesa Al-Hallak ◽  
Martin Sack ◽  
Peter Henningsen ◽  
...  

Thousands of refugees who have entered Europe experienced threatening conditions, potentially leading to post traumatic stress disorder (PTSD), which has to be detected and treated early to avoid chronic manifestation, especially in children. We aimed to evaluate and test suitable screening tools to detect PTSD in children. Syrian refugee children aged 4–14 years were examined using the PTSD-semi-structured interview, the Kinder-DIPS, and the Child Behavior Checklist (CBCL). The latter was evaluated as a potential screening tool for PTSD using (i) the CBCL-PTSD subscale and (ii) an alternative subscale consisting of a psychometrically guided selection of items with an appropriate correlation to PTSD and a sufficient prevalence (presence in more than 20% of the cases with PTSD). For both tools we calculated sensitivity, specificity, and a receiver operating characteristic (ROC) curve. Depending on the sum score of the items, the 20-item CBCL-PTSD subscale as used in previous studies yielded a maximal sensitivity of 85% and specificity of 76%. The psychometrically guided item selection resulted in a sensitivity of 85% and a specificity of 83%. The areas under the ROC curves were the same for both tools (0.9). Both subscales may be suitable as screening instrument for PTSD in refugee children, as they reveal a high sensitivity and specificity.


Author(s):  
Ashoka Mahapatra ◽  
K Nikitha ◽  
Sutapa Rath ◽  
Bijayini Behera ◽  
Kavita Gupta

Abstract Background Spread of carbapenem-resistant Enterobacterales (CRE) is a significant concern in intensive care unit (ICU) settings. Approaches to routine screening for CRE colonization in all ICU patients vary depending on institutional epidemiology and resources. The present study was aimed to evaluate the performance of HiCrome Klebsiella pneumoniae carbapenemase (KPC) agar for the detection of CRE colonization in ICU settings taking the Centers for Disease Control and Prevention (CDC) recommended method as reference. Methods Two-hundred and eighty rectal swabs (duplicate) from 140 patients were subjected to CRE detection in HiCrome KPC agar and MacConkey agar (CDC criteria). Results Using CDC method, total 41 CRE isolates were recovered comprising of 29 E scherichia coli, 11 Klebsiella, and 1 Enterobacter spp. On the other hand, 49 isolates of CRE recovered from 140 rectal swabs using HiCrome KPC agar, out of which 33 were E. coli, 15 Klebsiella, and 1 Enterobacter sp. Statistical Analysis Sensitivity, specificity, negative, and positive predictive values of CRE screening by HiCrome KPC agar were found to be 100% (91.4–100), 91.9% (84.8–95.8), 83.6% (70.9–91.4), and 100% (95.9–100), respectively, taking the CDC recommended method as reference. Conclusion HiCrome KPC agar has high sensitivity in screening CRE colonization. Further studies are needed to establish its applicability for detecting the predominant circulating carbapenemases in the Indian setting.


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