Successful diagnosis of Mycobacterium marinum infection by mNGS in a patient with Human Immunodeficiency Virus: a case report.

INTRODUCTION: Mycobacterium marinum infection rarely occurs and has atypical symptoms. It is challenging to distinguish disseminated M. marinum infection from multifocal dermatosis caused by other factors clinically. CASE PRESENTATION: Herein, we reported a 68-year-old male patient with Human Immunodeficiency Virus (HIV) who presented redness and swelling in his left hand after being stabbed by marine fish for over 2 months. Mycobacterium tuberculosis infection was considered according to biochemical and pathological examinations, while empirical anti-infection treatment was ineffective. RESULTS: The metagenomic next-generation sequencing (mNGS) detected a large amount of M. marinum sequences, and the patient was finally diagnosed with M. marinum infection. After one month of combination therapy with ethambutol, rifabutin, moxifloxacin, and linezolid, the swelling disappeared significantly. In this case, the successful application of mNGS in diagnosing and treating M. marinum infection has improved the understanding of the microbe both in the laboratory and clinically, especially in patients with HIV. CONCLUSIONS: For diseases with atypical symptoms or difficulty in determining the pathogens, mNGS is suggested in clinical procedures for rapid and accurate diagnosis and treatment.

Development and clinical application of loop-mediated isothermal amplification combined with lateral flow assay for rapid diagnosis of SARS-CoV-2.

BACKGROUND: The diagnostic assay leveraging multiple reverse transcription loop-mediated isothermal amplification (RT-LAMP) could meet the requirements for rapid nucleic acid detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: The devised assay merged the lateral flow assay with the RT-LAMP technology and designed specific primers for the simultaneous detection of the target and human-derived internal reference genes within a single reaction. An inquiry into the assay's limit of detection (LOD), sensitivity, and specificity was carried out. The effectiveness of this assay was validated using 498 clinical specimens. RESULTS: This LOD of the assay was determined to be 500 copies/mL, and there was no observed cross-reaction with other respiratory pathogens. The detection results derived from clinical specimens showed substantial concordance with those from real-time reverse transcription-polymerase chain reaction (RT-qPCR) (Cohen's kappa, 0.876; 95% CI: 0.833-0.919; p<0.005). The diagnostic sensitivity and specificity were 87.1% and 100%, respectively. CONCLUSION: The RT-LAMP assay, paired with a straightforward and disposable lateral immunochromatographic strip, achieves visual detection of dual targets for SARS-CoV-2 immediatly. Moreover, the entire procedure abstains from nucleic acids extraction. The samples are lysed at room temperature and subsequently proceed directly to the RT-LAMP reaction, which can be executed within 30 minutes at a constant temperature of 60-65°C. Then, the RT-LAMP amplification products are visualized using colloidal gold test strips. TRIAL REGISTRATION: This study was registered at the Chinese Clinical Trial Registry (Registration number: ChiCTR2200060495, Date of registration 2022-06-03).

Rapid detection of human adenovirus subgroup B using recombinase polymerase amplification assay.

Human adenovirus subgroup B (HAdV B) is one of the major pathogens of human respiratory virus infections, which has considerable transmission and morbidity in a variety of populations. Therefore, rapid and specific detection of HAdV B in clinical samples is essential for diagnosis. This study aimed to develop a product for rapid nucleic acid detection of HAdV B using recombinase polymerase amplification assay (RPA) and validate the performance of this method by using clinical samples. Results showed that this method achieved a lower limit of detection (LOD) of 10 copies/µL and had no cross-reactivity with other adenovirus subgroups or respiratory pathogens. In addition to high sensitivity, it can be completed within 30 min at 40 °C. There is no need to perform nucleic acid extraction on clinical samples. Taking qPCR as the gold standard, the RPA assay possessed a high concordance (Cohen's kappa, 0.896; 95% CI 0.808-0.984; P < 0.001), with a sensitivity of 87.80% and a specificity of 100.00%. The RPA assay developed in this study provided a simple and highly specific method, making it an important tool for rapid adenovirus nucleic acid detection and facilitating large-scale population screening in resource-limited settings.

N'-(4-Meth-oxy-benzyl-idene)-4-methyl-benzohydrazide.

The title compound, C(16)H(16)N(2)O(2), is the product of the reaction of 4-meth-oxy-benzaldehyde and 4-methyl-benzo-hydrazide. The dihedral angle between the substituted benzene rings is 17.6 (3)° and the meth-oxy C atom is almost coplanar with its attached ring [deviation = 0.019 (4) Å]. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, forming C(4) chains propagating along the b-axis direction.

N'-(2-Hy-droxy-benzyl-idene)-3-methyl-benzohydrazide.

The title compound, C(15)H(14)N(2)O(2), is the product of the reaction of 2-hy-droxy-benzaldehyde and 3-methyl-benzo-hydrazide. The dihedral angle between the substituted benzene rings is 19.5 (3)° and an intra-molecular O-H⋯N hydrogen bond generates an S(6) ring motif. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds to generate C(4) chains propagating in [001] and C-H⋯O inter-actions to the same O-atom acceptor reinforce the chains.