A new replication medium enables a rapid identification of φx-174 virus by synchronous fluorescence of Tryptophan.

Development of rapid methods for identification of bacteriophages based on their intrinsic fluorescence is challenging. Pure bacteriophages may be detected based on the strong fluorescence of the amino acid Tryptophan that exist in their proteins. Nevertheless, Tryptophan is a molecule that also exist in high quantities in the bacterial hosts and their cultivation media. In this work, we show that simple separation of the bacteriophage φx-174 from its E.coli host (grown on standard cultivation medium) by filtration is not sufficient for its identification based on the intrinsic fluorescence of its Tryptophan content. This is mostly because of the tryptophan residues that derive from the cultivation medium. We fabricate a new cultivation medium that does not have any significant fluorescence overlap with Tryptophan. By utilization of this new cultivation medium, we can identify φx174 based on the spectral fingerprint of its intrinsic Tryptophan content by synchronous fluorescence measurements.

Validation and Concordance Analysis of a New Lateral Flow Assay for Detection of Histoplasma Antigen in Urine

Histoplasmosis is a major cause of mortality in people living with HIV (PLHIV). Rapid methods to diagnose Histoplasma capsulatum disease could dramatically decrease the time to initiate treatment, resulting in reduced mortality. The aim of this study was to validate a MiraVista® Diagnostics (MVD) Histoplasma urine antigen lateral flow assay (MVD LFA) for the detection of H. capsulatum antigen (Ag) in urine and compare this LFA against the MVista® Histoplasma Ag quantitative enzyme immunoassays (MVD EIA). We assessed the MVD LFA using a standardized reference panel of urine specimens from Colombia. We tested 100 urine specimens, 26 from PLHIV diagnosed with histoplasmosis, 42 from PLHIV with other infectious diseases, and 32 from non-HIV infected persons without histoplasmosis. Sensitivity and specificity of the MVD LFA was 96%, compared with 96% sensitivity and 77% specificity of the MVD EIA. Concordance analysis between MVD LFA and the MVD EIA displayed an 84% agreement, and a Kappa of 0.656. The MVD LFA evaluated in this study has several advantages, including a turnaround time for results of approximately 40 min, no need for complex laboratory infrastructure or highly trained laboratory personnel, use of urine specimens, and ease of performing.

Validated green chromatographic methods for determination of amlodipine and celecoxib in presence of methylacetophenone

Aim: Green, accurate and rapid methods, namely LC–MS/MS and thin layer chromatography-densitometric methods, were developed for determination of amlodipine besylate and celecoxib in presence of its process-related impurities, 4-methylacetophenone in pure and formulated tablets. Results: LC–MS/MS was achieved on ZORBAX Eclipse Plus C18 column using methanol: aqueous solution of 5 mM formic acid (95:5 v/v). High sensitivity with low limit of detection values 0.00028, 0.00027 and 0.0003 for amlodipine, celecoxib and 4-methylacetophenone, respectively were obtained. While, thin layer chromatography-densitometric was established using methanol: water: ammonia (70: 25: 1.5, by volume). Good linearity was obtained in the range of 0.1–10 μg/band, 1–150 μg/band and 0.01–2 μg/band for amlodipine, celecoxib and 4-methylacetophenone, respectively. Conclusion: The proposed method validation was achieved according to ICH guidelines. Those methods possess advantages of being ecofriendly methods which permit their application in quality control laboratories.

Application of Nanopore Sequencing (MinION) for the Analysis of Bacteriome and Resistome of Bean Sprouts

The aspiration these days is to apply rapid methods for parallel analysis of bacteriome and resistome of food samples to increase food safety and prevent antibiotic resistance genes (ARGs) spreading. In this work, we used nanopore sequencing (NS) to determine the diversity and dynamics of the microbiome and resistome in two types of bean sprouts. We proved that NS provided an easy, quick, and reliable way to identify the microbiome and resistome of a food sample also. The species diversity obtained by NS and by cultivation methods with MALDI-TOF MS identification was comparable. In both samples, before and after cultivation (30 °C, 48 h), the dominant part of bacteriome formed Gammaproteobacteria (Enterobacteriaceae, Erwiniaceae, Pseudomonadaceae, Moraxellaceae) and then Firmicutes (Streptococcaceae). The diversity and abundance of single ARGs groups were comparable for both samples despite bacteriome differences. More than 50% of the detected ARGs alignments were mutations conferring resistance to aminoglycosides (16S rRNA), resistance to fluoroquinolones (gyrA, gyrB, parC, parD) and elfamycin (EF-Tu). ARGs encoding efflux pumps formed more than 30% of the detected alignments. Beta-lactamases were represented by many variants, but were less abundant.

Evaluation of seven different rapid methods for nucleic acid detection of SARS-COV-2 virus

Background In the current COVID-19 pandemic there is mass screening of SARS-CoV-2 happening round the world due to the extensive spread of the infections. There is a high demand for rapid diagnostic tests to expedite identification of cases and to facilitate early isolation and control spread. Hence this study evaluates seven different rapid nucleic acid detection assays that are commercially available for SARS- CoV- 2 virus detection. Methods Nasopharyngeal samples were collected from 4859 participants and were tested for SARS-CoV-2 virus by the gold standard RT-PCR method along with one of these seven rapid methods of detection. Evaluation of the rapid nucleic acid detection assays was done by comparing the results of these rapid methods with the gold standard RT-qPCR results for SARS-COV-2 detection. Results AQ-TOP had the highest sensitivity (98%) and strong kappa value of 0.943 followed by Genechecker and Abbot ID NOW. The POCKIT (ii RT-PCR) assay had the highest test accuracy of 99.29% followed by Genechecker and Cobas Liat. Atila iAMP showed the highest percentage of invalid reports (35.5%) followed by AQ-TOP with 6% and POCKIT with 3.7% of invalid reports. Conclusion Genechecker system, Abbott ID NOW and Cobas Liat, were found to have best performance and agreement when compared to the standard RT-PCR for COVID-19 detection. With further research, these rapid tests have the potential to be employed in large scale screening of COVID-19.