Evaluation of Three Automated Nontreponemal Rapid Plasma Reagin (RPR) Tests for the Laboratory Diagnosis of Syphilis.

Automated nontreponemal rapid plasma reagin (RPR) tests were recently introduced in the United States for syphilis testing and limited performance data are available. In collaboration with the Association of Public Health Laboratories, three public health laboratories (PHL) were chosen through a competitive selection process to evaluate the performance of three FDA-cleared automated RPR test systems: BioPlex 2200 Syphilis Total & RPR assay (Bio-Rad Laboratories), AIX 1000 (Gold Standard Diagnostics), and ASI Evolution (Arlington Scientific). Panels prepared at the CDC included: a qualitative panel comprised of 734 syphilis reactive/nonreactive sera; a quantitative panel of 50 syphilis reactive sera (RPR titer 1:64 to 1:1,024); and a reproducibility panel of 15 nonreactive and reactive sera (RPR titer 1:1 to 1:64). Panels were shipped frozen to the PHL and tested on the automated RPR systems following manufacturers' instructions. Prior test results were blinded to all laboratories. When compared to manual RPR (Arlington Scientific) performed at the CDC as a reference test, the qualitative panel results demonstrated an overall concordance of 95.9% for AIX 1000, 94.6% for ASI Evolution, and 92.6% for Bioplex RPR; quantitative panel showed within range titer of 2-fold for 94% of specimens for AIX 1000, 68% for ASI Evolution, and 64% for BioPlex RPR, and the reproducibility testing panel demonstrated point estimates ranging from 69 to 95%. Automated RPR instruments could reduce turnaround time and minimize interpretation errors. However, additional evaluations with more specimens could assist laboratories with implementing automated RPR tests and understanding their limitations.

Colossal Enhancement of Near-Field Thermal Radiation Across Hundreds of Nanometers between Millimeter-Scale Plates through Surface Plasmon and Phonon Polaritons Coupling.

Coupling modes between surface plasmon polaritons (SPPs) and surface phonon polaritons (SPhPs) play a vital role in enhancing near-field thermal radiation but are relatively unexplored, and no experimental result is available. Here, we consider the NFTR enhancement between two identical graphene-covered SiO2 heterostructures with millimeter-scale surface area and report an experimentally record-breaking ∼64-fold enhancement compared to blackbody (BB) limit at a gap distance of 170 nm. The energy transmission coefficient and radiation spectra show that the physical mechanism behind the colossal enhancement is the coupling between the surface plasmon and phonon polaritons.

Increased Discrimination of Treponema pallidum Strains by Subtyping With a 4-Component System Incorporating a Mononucleotide Tandem Repeat in rpsA.

A guanine mononucleotide repeat in the rpsA (tp0279) gene was evaluated for improved strain discrimination using 72 Treponema pallidum-positive specimens. The tandem repeat combined with the enhanced Centers for Disease Control and Prevention typing system resulted in increased discrimination and should be useful for molecular epidemiologic studies on syphilis especially in outbreaks and among men who have sex with men.

Evaluation of a Rapid Syphilis Test in an Emergency Department Setting in Detroit, Michigan.

BACKGROUND: Syphilis transmission can be prevented by prompt diagnosis and treatment of primary and secondary infection. We evaluated the performance of a point-of-care rapid syphilis treponemal (RST) test in an emergency department (ED) setting. METHODS: Between June 2015 and April 2016, men aged 18 to 34 years seeking services in a Detroit ED, and with no history of syphilis, were screened for syphilis with the RST test, rapid plasma reagin (RPR) test, and Treponema pallidum particle agglutination assay (TP-PA). A positive reference standard was both a reactive RPR and a reactive TP-PA. We compared test results in self-reported men who have sex with men (MSM) to non-MSM. RESULTS: Among 965 participants, 10.9% of RST tests were reactive in MSM and only 1.5% in non-MSM (P < 0.001). Sensitivity of the RST test was 76.9% and specificity was 99.0% (positive predictive value, 50.0%) compared with the positive reference standard. Three discordant specimens found negative with the RST test but positive with the reference standard had an RPR titer of 1:1, compared with 10 specimens with concordant positive results that had a median RPR titer of 1:16. The RST sensitivity was 50.0% (positive predictive value, 68.4%) compared to the TP-PA test alone. Among men seeking care in an ED, the RST detected 76.9% of participants with a reactive RPR and TP-PA. CONCLUSIONS: The RST test detected all of the participants with an RPR titer ≥1:2 but less than 20% of participants with a positive TP-PA and negative RPR. The RST test was useful to detect a high proportion of participants with an active syphilis in an urban ED.

Laboratory Evaluation of a Commercially Available Rapid Syphilis Test.

Serological diagnosis of syphilis depends on assays that detect treponemal and nontreponemal antibodies. Laboratory certification and trained personnel are needed to perform most of these tests, while high costs and long turnaround time can hinder treatment initiation or linkage to care. A rapid treponemal syphilis test (RST) that is simple to perform, accessible, and inexpensive would be ideal. The Syphilis Health Check (SHC) assay is the only Food and Drug Administration (FDA)-cleared and Clinical Laboratory Improvement Amendments (CLIA)-waived RST in the United States. In this study, 1,406 archived human serum samples were tested using SHC and traditional treponemal and nontreponemal assays. Rapid test results were compared with treponemal data alone and with a laboratory test panel consensus defined as being reactive by both treponemal and nontreponemal assays for a given specimen, or nonreactive by both types of assays. The sensitivity and specificity of the SHC assay compared with treponemal tests alone were 88.7% (95% confidence interval [CI], 86.2 to 90.0%) and 93.1% (95% CI, 90.0 to 94.9%), respectively, while comparison with the laboratory test panel consensus showed 95.7% (95% CI, 93.6 to 97.2%) sensitivity and 93.2% (95% CI, 91.0 to 95.1%) specificity. The data were further stratified based on age, sex, pregnancy, and HIV status. The sensitivity and specificity of the SHC assay ranged from 66.7% (95% CI, 46.0 to 83.5%) to 91.7% (95% CI, 87.7 to 94.7%) and 88% (95% CI, 68.8 to 97.5%) to 100% (95% CI, 47.8 to 100%), respectively, across groups compared to traditional treponemal assays, generally increasing for all groups except the HIV-positive (HIV+) population when factoring in the laboratory test panel consensus. These data contribute to current knowledge of the SHC assay performance for distinct populations and may guide use in various settings.

[Optimization of flash-type extraction technology of alisol B 23-acetate from Alismatis Rhizoma by response surface methodology].

Response surface methodology was used to optimize and obtain the optimal flash-type extraction technology of alisol B 23-acetate from Alismatis Rhizoma. With the extraction rate of alisol B 23-acetate as an indicator, single-factor test was used to investigate the effect of ethanol volume fraction, liquid-solid ratio, extraction times and extracting time on the extraction rate of alisol B 23-acetate.The results were combined with Box-Benhnken design and response surface analysis to optimize the technology parameters for extraction process of Alismatis Rhizoma and obtain the optimal flash-type extraction technology under the following conditions： ethanol volume fraction 80%, liquid-solid ratio 12∶1, extraction 4 times, 114 s/time. Flash-type extraction technology of alisol B 23-acetate by response surface methodology is stable, time-saving, efficient, and with the advantages of room temperature extraction and no component damage, so it can be used for massive production.

[Fast measurement method based on near infrared spectroscopy in extraction process of Tianshu capsules].

Based on the near infrared spectroscopy, partial least square (PLS) method was used to respectively develop the quantitative calibration models to fast measure the contents of the total solid and ferulic acid in extraction process of Tianshu capsule extracts. The results showed that in the quantitative model of solid content, the correlation coefficients (R²) of calibration set and cross validation set were 0.967 301 and 0.947 726. The root-mean square error of calibration set (RMSEC) was 0.054 7 and root-mean square error of cross validation set (RMSECV) was 0.069 8. Besides, in the quantitative model of ferulic acid, the correlation coefficients (R²) of calibration set and cross validation set were 0.986 879 and 0.962 243. RMSEC was 1.402 6 and RMSECV was 2.400 2. When the established models were applied to on-line monitoring, the correlation coefficients of predicted results and measured values for total solid content and ferulic acid were 0.993 3 and 0.991 6; root-mean square error of predicted value (RMSEP) was 0.039 3 and 1.669 3 respectively; mean relative deviation of predicted value (RSEP) was 3.49% and 3.58%. The results indicated that the established models can be used to fast measure the contents of the total solid and ferulic acid in extraction process of Tianshu capsule extracts.

[Quantitative and qualitative evaluation on tablets of Ginkgo biloba leaves using fingerprint and LC-MS analysis].

A reasonable method for the quality control of tablets of Ginkgo biloba leaves was established in this paper. The total flavonol glycosides and terpene lactones of G. biloba tablets were quantified by HPLC. Totally, 16 batches of the commercially available tablets of G. biloba leaves were determined. Among of them, 2 batches were unqualified in the content of total flavonol glycosides, and 3 batches were unqualified in the content of terpene lactones. A validated HPLC fingerprint method was established to evaluate the commercially available tablets of G. biloba leaves with the assistance of LC-MS. Sixteen batches showed the similarity of 0.763-0.989. There were 31 fingerprint chromatogram peaks were identified as flavonoids compositions by LC-MS. This provides a research idea for the quality control of tablets of G. biloba leaves.

Identification of Anncaliia algerae in Ascites in an Immunosuppressed Patient, China.

Anncaliia algerae, a microsporidium, has risen to prominence as an opportunistic pathogen, particularly afflicting individuals who are immunocompromised with conditions such as rheumatoid arthritis, organ transplantation, and hematologic malignancy. Surprisingly, despite its recognized impact, the identification of A algerae in ascitic fluid has not been documented. As such, we pinpointed A algerae as the probable instigator of ascitic accumulation in a patient with a history of acute myeloid leukemia and extended periods of immunosuppressive therapy. For this patient, there were no signs of A algerae-related infections (eg, myositis), vocal cord involvement, or disseminated infection. The presence of A algerae was finally identified by next-generation metagenomic sequencing analysis of the ascitic fluid. Clinical presentation was characterized by elevated C-reactive protein levels (110.7 mg/L), diminished platelet count (48 × 109/L), abdominal distension secondary to ascitic fluid accumulation, and lower limb pain, and it showed marked improvement following a 4-day regimen of sulfamethoxazole/trimethoprim and albendazole. Despite this promising response, the patient succumbed to aspiration of vomitus. This case underscores the importance of considering rarer organisms, such as A algerae infection, in patients who are immunocompromised and present with unexplained ascites accumulation. It highlights the potential effectiveness of sulfamethoxazole/trimethoprim and albendazole in managing such cases. Further research is warranted to elucidate optimal management strategies and improve outcomes in similar clinical scenarios.

Association between ABO blood groups and hematological myeloid neoplasms in adolescents and adults.

Background: Prior research suggests a potential link between ABO blood types and susceptibility to various malignancies. The correlation between ABO blood types and hematological myeloid neoplasms, however, remains inadequately explored. Objective: This study investigates the association between ABO blood groups and the incidence of hematological myeloid neoplasms in adolescents and adults. Methods: In this retrospective clinical study, 1,022 adolescent and adult cases of myeloid neoplasms diagnosed at our institution were initially considered. After excluding conditions potentially linked to ABO blood types from prior studies, 792 eligible cases were analyzed. These cases were categorized based on disease subtypes and compared with a control group for blood type distribution. Results: Our findings reveal a significantly higher prevalence of blood type A in patients with myeloid neoplasms compared to the control group, except for chronic myelocytic leukemia and myeloproliferative neoplasms. Conversely, the prevalence of blood type AB in myeloid neoplasms was notably lower than in the control group. Conclusion: The study suggests a potential association between ABO blood types and the risk of developing hematological myeloid neoplasms in adolescents and adults. Further research is warranted to elucidate the underlying mechanisms of this relationship.

A Novel Inflammatory-Nutritional Prognostic Scoring System for Patients with Diffuse Large B Cell Lymphoma.

Purpose: This study aimed to examine the predictive ability of inflammatory and nutritional markers and further establish a novel inflammatory nutritional prognostic scoring (INPS) system. Patients and Methods: We collected clinicopathological and baseline laboratory data of 352 patients with DLBCL between April 2010 and January 2023 at the First affiliated hospital of Ningbo University. Eligible patients were randomly divided into training and validation cohorts (n = 281 and 71, respectively) in an 8:2 ratio. We used the least absolute shrinkage and selection operator (LASSO) Cox regression model to determine the most important factors among the eight inflammatory-nutritional variables. The impact of INPS on OS was evaluated using the Kaplan-Meier curve and the Log rank test. A prognostic nomogram was developed based on the multivariate Cox regression method. Then, we used the concordance index (C-index), calibration plot, and time-dependent receiver operating characteristic (ROC) analysis to evaluate the prognostic performance and predictive accuracy of the nomogram. Results: Seven inflammatory-nutritional biomarkers, including neutrophil-lymphocyte ratio (NLR), prognostic nutritional index (PNI), body mass index (BMI), monocyte-lymphocyte ratio (MLR), prealbumin, C reactive protein, and D-dimer were selected using the LASSO Cox analysis to construct INPS, In the multivariate analysis, IPI-High-intermediate group, IPI-High group, high INPS were independently associated with OS, respectively. The prognostic nomogram for overall survival consisting of the above two indicators showed excellent discrimination. The C-index for the nomogram was 0.94 and 0.95 in the training and validation cohorts. The time-dependent ROC curves showed that the predictive accuracy of the nomogram for OS was better than that of the NCCN-IPI system. Conclusion: The INPS based on seven inflammatory-nutritional indexes was a reliable and convenient predictor of outcomes in DLBCL patients.

Silencing of PD-1 combined with EBV-specific killer T cells for the treatment of EBV-associated B lymphoma.

Epstein-Barr Virus (EBV) infection is closely associated with the development of lymphoma, as it plays a significant role in the malignant transformation of lymphocytes. The expression of programmed death-1 (PD-1), which binds to PD-L1 in tumor cells, can lead to immune evasion by lymphoma cells and promote tumor progression. In this study, immortalized B lymphoblastoid cell lines (B-LCLs) positive for EBV-specific proteins were established from human peripheral mononuclear cells (PBMCs) using EBV induction along with CpG-ODN 2006 and cyclosporin A. EBV-specific T cells (EBVST) were generated by multiple immunizations of CD3+ T lymphocytes using irradiated B-LCLs. Flow cytometry analysis confirmed the activation of EBVST through the detection of CD3+, CD4+, and CD8+ markers. Co-incubation of EBVST with EBV-positive B lymphocyte cell lines resulted in the secretion of perforin by EBVST, leading to granzyme B-mediated cell death and an increase in LDH levels. Silencing PD-1 in EBVST cells enhanced perforin production, increased granzyme B release, and upregulated cell death in co-incubated B lymphocytes. In a nude mice tumor transplantation model, silencing PD-1 in combination with EBV-specific killer T cells exhibited the maximum inhibition of B-lymphoblastoma. This treatment upregulated the expression of proteins associated with apoptosis and immune response, while inhibiting anti-apoptotic protein expression in tumor tissues. Silencing PD-1 also increased the infiltration of EBV-specific killer T cells in the tumor tissues. Overall, PD-1 silencing enhanced the tumor targeting effect of EBV-specific killer T cells on EBV-infected B lymphocytes and attenuated the immune escape effect mediated by the PD-1 pathway.

Development and evaluation of rapid and simple detection of Klebsiella pneumoniae using closed dumbbell-mediated isothermal amplification diagnostic assay.

Introduction: Klebsiella pneumoniae (K. pneumoniae) is the most common pathogen causing hospital respiratory tract infection and epidemic. Gold standard procedures of microscopic examination and biochemical identification are widely used in clinical diagnosis with disadvantages of low sensitivity, time-consuming and sophisticated equipment requiring. An efficient, nucleic acid amplification-based sensitive and specific on-site identification of K. pneumoniae in clinical is necessary to facilitate clinical medication and disease control. Methods: We developed a closed dumbbell mediated isothermal amplification (CDA) assay for the rapid and sensitive detection of conserved rcsA gene in K. pneumoniae by real-time fluorescence monitoring and end-point colorimetric judgement. We designed and selected a pair of inner primers of CDA to detect K. pneumoniae. Then outer and loop primers were designed and verified to accelerate CDA reaction to achieve more efficient detection of K. pneumoniae. Results: The results showed the detection limit of CDA assay was 1.2 × 10-5 ng/µL (approximately 1 copy of the target gene) within 60 min, which was 100-fold more sensitive than real-time quantitative PCR (qPCR). Several pathogen genomic DNAs (Staphylococcus aureus, Shigella sonnei, Vibrio parahaemolyticus, Escherichia coli, Candida glabrata, Candida tropicalis, Candida parapsilosis, Candida albicans, Streptococcus agalactiae, Rickettsia, Listeria monocytogenes, Pseudomonas aeruginosa, Klebsiella oxytoca, and Klebsiella aerogenes) were used to evaluate the sensitivity and specificity of the established K. pneumoniae CDA assay. Total 224 batches of samples from other strains tested were negative and 296 batches of extracted K. pneumoniae DNA samples were positive by the developed CDA amplification approach, revealing high specificity and specificity of the diagnostic assay. In addition, the results of real-time fluorescence amplification of the K. pneumoniae CDA were in consistent with those of end-point colorimetric results. Discussion: The established real-time fluorescence and visual CDA assays of K. pneumoniae with merits of rapid, sensitive and specificity could be helpful for on-site diagnosis and clinical screening in rural areas.

Development and validation of a model for the early prediction of progression from essential thrombocythemia to post-essential thrombocythemia myelofibrosis: a multicentre retrospective study.

Background: Essential thrombocythemia (ET), a myeloproliferative neoplasm (MPN), has a substantial risk of evolving into post-essential thrombocythemia myelofibrosis (post-ET MF). This study aims to establish a prediction nomogram for early prediction of post-ET MF in ET patients. Methods: The training cohort comprised 558 patients from 8 haematology centres between January 1, 2010, and May 1, 2023, while the external validation cohort consisted of 165 patients from 6 additional haematology centres between January 1, 2010, and May 1, 2023. Univariable and multivariable Cox regression analysis was performed to identified independent risk factors and establish a nomogram to predict the post-ET MF free survival. Both bias-corrected area under the curve (AUC), calibration curves and concordance index (C-index) were employed to assess the predictive accuracy of the nomogram. Findings: Multivariate Cox regression demonstrated that elevated red blood cell distribution width (RDW), elevated levels of lactate dehydrogenase (LDH) and the level of haemoglobin (Hb), a history of smoking and the presence of splenomegaly were independent risk factors for post-ET MF. The C-index displayed of the training and validation cohorts were 0.877 and 0.853. The 5 years, 10 years AUC values in training and external validation cohorts were 0.948, 0.769 and 0.978, 0.804 respectively. Bias-corrected curve is close to the ideal curve and revealed a strong consistency between actual observation and prediction. Interpretation: We developed a nomogram capable of predicting the post-ET MF free survival probability at 5 years and 10 years in ET patients. This tool helps doctors identify patients who need close monitoring and appropriate counselling. Funding: This research was funded by the Key R&D Program of Zhejiang (No. 2022C03137); the Public Technology Application Research Program of Zhejiang, China (No. LGF21H080003); and the Zhejiang Medical Association Clinical Medical Research special fund project (No. 2022ZYC-D09).

Broad specificity AhpC-like peroxiredoxin and its thioredoxin reductant in the sparse antioxidant defense system of Treponema pallidum.

Little is known about the mechanisms by which Treponema pallidum (Tp), the causative agent of syphilis, copes with oxidative stress as it establishes persistent infection within its obligate human host. The Tp genomic sequence indicates that the bacterium's antioxidant defenses do not include glutathione and are limited to just a few proteins, with only one, TP0509, offering direct defense against peroxides. Although this Tp peroxiredoxin (Prx) closely resembles AhpC-like Prxs, Tp lacks AhpF, the typical reductant for such enzymes. Functionally, TpAhpC resembles largely eukaryotic, nonAhpC typical 2-Cys Prx proteins in using thioredoxin (Trx, TP0919) as an efficient electron donor and exhibiting broad specificity toward hydroperoxide substrates. Unlike many of the eukaryotic Prxs, however, TpAhpC is relatively resistant to inactivation during turnover with hydroperoxide substrates. As is often observed in typical 2-Cys Prxs, TpAhpC undergoes redox-sensitive oligomer formation. Quantitative immunoblotting revealed that TpTrx and TpAhpC are present at very high levels (over 100 and 300 microM, respectively) in treponemes infecting rabbit testes; their redox potentials, at -242 +/- 1 and -192 +/- 2 mV, respectively, are consistent with the role of TpTrx as the cellular reductant of TpAhpC. Transcriptional analysis of select antioxidant genes confirmed the presence of high mRNA levels for ahpC and trx which diminish greatly when spirochetes replicate under in vitro growth conditions. Thus, T. pallidum has evolved an extraordinarily robust, broad-spectrum AhpC as its sole mechanism for peroxide defense to combat this significant threat to treponemal growth and survival during infection.

Adoption value of support vector machine algorithm-based computed tomography imaging in the diagnosis of secondary pulmonary fungal infections in patients with malignant hematological disorders.

This study aimed to assess the feasibility of diagnosing secondary pulmonary fungal infections (PFIs) in patients with hematological malignancies (HM) using computerized tomography (CT) imaging and a support vector machine (SVM) algorithm. A total of 100 patients with HM complicated by secondary PFI underwent CT scans, and they were included in the training group. Concurrently, 80 patients with the same underlying disease who were treated at our institution were included in the test group. The types of pathogens among different PFI patients and the CT imaging features were compared. Radiomic features were extracted from the CT imaging data of patients, and a diagnostic SVM model was constructed by integrating these features with clinical characteristics. Aspergillus was the most common pathogen responsible for PFIs, followed by Candida, Pneumocystis jirovecii, Mucor, and Cryptococcus, in descending order of occurrence. Patients typically exhibited bilateral diffuse lung lesions. Within the SVM algorithm model, six radiomic features, namely the square root of the inverse covariance of the gray-level co-occurrence matrix (square root IV), the square root of the inverse covariance of the gray-level co-occurrence matrix, and small dependency low gray-level emphasis, significantly influenced the diagnosis of secondary PFIs in patients with HM. The area under the curve values for the training and test sets were 0.902 and 0.891, respectively. Therefore, CT images based on the SVM algorithm demonstrated robust predictive capability in diagnosing secondary PFIs in conjunction with HM.

The gut microbiota correlate with the disease characteristics and immune status of patients with untreated diffuse large B-cell lymphoma.

Background: Gut microbiota characteristics in patients with diffuse large B-cell lymphoma (DLBCL) are reportedly different when compared with the healthy population and it remains unclear if the gut microbiota affects host immunity and clinical disease features. This research investigated the gut microbiota in patients with untreated DLBCL and analyzed its correlation with patient clinical characteristics, humoral, and cell immune status. Methods: Thirty-five patients with untreated DLBCL and 20 healthy controls (HCs) were recruited to this study and microbiota differences in stool samples were analyzed by 16S rDNA sequencing. Absolute ratios of immune cell subset counts in peripheral blood were detected by flow cytometry and peripheral blood cytokine levels were detected by enzyme-linked immunosorbent assay. Relationships between changes in patient microbiomes and clinical characteristics, such as clinical stage, international prognostic index (IPI) risk stratification, cell origin, organ involved and treatment responses were investigated and correlations between differential microbiota and host immune indices were analyzed. Results: The alpha-diversity index of intestinal microecology in DLBCL patients was not significantly different when compared with HCs (P>0.05), nonetheless beta-diversity was significantly decreased (P=0.001). p_Proteobacteria were dominant in DLBCL, while p_Bacteroidetes abundance was significantly decreased when compared with HCs (P<0.05). Gut microbiota characteristics were identified that were associated with clinical features, such as tumor load, risk stratification and cell origin, and correlation analyses were performed between differential flora abundance associated with these clinical features and host immune status. The p_Firmicutes was positively correlated with absolute lymphocyte values, g_Prevotella_2 and s_un_g_Prevotella_2 were negatively correlated with absolute lymphocyte values, T cell counts and CD4 cell counts, while g_Pyramidobacter, s_un_g_Pyramidobacter, and f_Peptostreptococcaceae were negatively correlated with IgA. Conclusions: Dominant gut microbiota, abundance, diversity, and structure in DLBCL were influenced by the disease, correlated with patient immune status and this suggested that the microecology-immune axis may be involved in regulating lymphoma development. In the future, it may be possible to improve immune function in patients with DLBCL by regulating the gut microbiota, improve treatment response rates and increase patient survival rates.

Evaluation of the effect of extended refrigerated storage of serum and plasma specimens on syphilis serologic test results.

The effect of extended refrigerated storage of 14 serum and plasma specimens on 5 syphilis serologic tests was evaluated for 16 weeks. Higher stability of nontreponemal and treponemal antibodies in serum was recorded compared to plasma. Described work may provide insights on refrigerated specimens' stability and suitability for syphilis tests.

Selective Whole-Genome Amplification as a Tool to Enrich Specimens with Low Treponema pallidum Genomic DNA Copies for Whole-Genome Sequencing.

Downstream next-generation sequencing (NGS) of the syphilis spirochete Treponema pallidum subspecies pallidum (T. pallidum) is hindered by low bacterial loads and the overwhelming presence of background metagenomic DNA in clinical specimens. In this study, we investigated selective whole-genome amplification (SWGA) utilizing multiple displacement amplification (MDA) in conjunction with custom oligonucleotides with an increased specificity for the T. pallidum genome and the capture and removal of 5'-C-phosphate-G-3' (CpG) methylated host DNA using the NEBNext Microbiome DNA enrichment kit followed by MDA with the REPLI-g single cell kit as enrichment methods to improve the yields of T. pallidum DNA in isolates and lesion specimens from syphilis patients. Sequencing was performed using the Illumina MiSeq v2 500 cycle or NovaSeq 6000 SP platform. These two enrichment methods led to 93 to 98% genome coverage at 5 reads/site in 5 clinical specimens from the United States and rabbit-propagated isolates, containing >14 T. pallidum genomic copies/µL of sample for SWGA and >129 genomic copies/µL for CpG methylation capture with MDA. Variant analysis using sequencing data derived from SWGA-enriched specimens showed that all 5 clinical strains had the A2058G mutation associated with azithromycin resistance. SWGA is a robust method that allows direct whole-genome sequencing (WGS) of specimens containing very low numbers of T. pallidum, which has been challenging until now. IMPORTANCE Syphilis is a sexually transmitted, disseminated acute and chronic infection caused by the bacterial pathogen Treponema pallidum subspecies pallidum. Primary syphilis typically presents as single or multiple mucocutaneous lesions and, if left untreated, can progress through multiple stages with various clinical manifestations. Molecular studies often rely on direct amplification of DNA sequences from clinical specimens; however, this can be impacted by inadequate samples due to disease progression or timing of patients seeking clinical care. While genotyping has provided important data on circulating strains over the past 2 decades, WGS data are needed to better understand strain diversity, perform evolutionary tracing, and monitor antimicrobial resistance markers. The significance of our research is the development of an SWGA DNA enrichment method that expands the range of clinical specimens that can be directly sequenced to include samples with low numbers of T. pallidum.

Next-generation sequencing technology for diagnosis and efficacy evaluation of a patient with visceral leishmaniasis: A case report.

BACKGROUND: Visceral leishmaniasis (VL) is a parasitic disease caused by Leishmania and transmitted by infected sand flies. VL has a low incidence in China, and its clinical presentation is complex and atypical. This disease is easily misdiagnosed and can become life-threatening within a short period of time. Therefore, early, rapid and accurate diagnosis and treatment of the disease are essential. CASE SUMMARY: A 25-year-old male patient presented with the clinical manifestations of irregular fever, hepatosplenomegaly, increased polyclonal globulin, and pancytopenia. The first bone marrow puncture biopsy did not provide a clear diagnosis. In order to relieve the pressure and discomfort of the organs caused by the enlarged spleen and to confirm the diagnosis, splenectomy was performed, and hemophagocytic syndrome was diagnosed by pathological examination of the spleen biopsy. Following bone marrow and spleen pathological re-diagnosis and metagenomic next-generation sequencing (mNGS) technology detection, the patient was finally diagnosed with VL. After treatment with liposomal amphotericin B, the body temperature quickly returned to normal and the hemocytes recovered gradually. Post-treatment re-examination of the bone marrow puncture and mNGS data showed that Leishmania was not detected. CONCLUSION: As a fast and accurate detection method, mNGS can diagnose and evaluate the efficacy of treatment in suspicious cases of leishmaniasis.