Comparative evaluation of the STANDARD M10 and Xpert C. difficile assays for detection of toxigenic Clostridioides difficile in stool specimens.

This study compared the performance of two commercial molecular assays, the STANDARD M10 Clostridioides difficile assay (M10) and the Xpert C. difficile assay (Xpert), for detecting toxigenic C. difficile in stool specimens. A total of 487 consecutive stool specimens submitted for routine C. difficile testing between June and November 2023 were included. Following routine testing using C. DIFF QUIK CHEK COMPLETE (QCC), M10 and Xpert were tested in parallel, alongside toxigenic culture (reference standard). Additionally, two-step algorithms, using QCC on the first step and either M10 or Xpert on the second step, were assessed. Both M10 and Xpert demonstrated a sensitivity and negative predictive value (NPV) of 100%. M10 exhibited significantly higher specificity and positive predictive value (PPV; 91.9% and 64.2%, respectively) than Xpert (90.3% and 59.8%, respectively). Both two-step algorithms showed a sensitivity and NPV of 98.4% and 99.8%, respectively. The specificity and PPV of the two-step algorithm using M10 (95.2% and 75.0%, respectively) were slightly higher than those of the one using Xpert (94.8% and 73.2%, respectively), without statistical significance. Receiver operating characteristic curve analysis, assessing the predictive ability of cycle threshold (Ct) values for the detection of free toxin, exhibited an area under the curve of 0.825 for M10 and 0.843 for Xpert. This indicates the utility of Ct values as predictors for the detection of free toxin in both assays. In conclusion, M10 proves to be an effective diagnostic tool with performance comparable to Xpert, whether utilized independently or as part of a two-step algorithm.

Comparison of the STANDARD F and SD BIOLINE stool antigen tests for diagnosis of Helicobacter pylori infection.

We compared the performance of the STANDARD F and SD BIOLINE stool antigen tests in 335 patients. The performance of STANDARD F (sensitivity: 95.6%; specificity: 94%) was highly comparable to that of SD BIOLINE (sensitivity: 92.6%; specificity: 93.5%), suggesting that STANDARD F is useful for the detection of Helicobacter pylori infection.

Performance Evaluation of MolecuTech REBA Myco-ID Using HybREAD480 for Identification of Nontuberculous Mycobacteria.

BACKGROUND: Rapid and accurate identification of nontuberculous mycobacteria (NTM) species is essential for the diagnosis and treatment of NTM disease. MolecuTech REBA Myco-ID (YD Diagnostics, Yongin, Korea) is a line probe assay for identification of NTM species and can be performed using HybREAD480, an instrument for automating the post-PCR steps. In this study, we assessed the performance of MolecuTech REBA Myco-ID using HybREAD480. METHODS: Seventy-four reference strains, including 65 Mycobacterium strains and nine non-Mycobacterium strains within the order Mycobacteriales, were used to determine the analytical specificity of MolecuTech REBA Myco-ID. The clinical performance of this assay was evaluated with 192 clinical Mycobacterium strains, and the assay results were compared to those of multigene sequencing-based typing. RESULTS: The accuracy of MolecuTech REBA Myco-ID for the 74 reference strains and 192 clinical strains was 77.0% (57/74; 95% confidence interval [CI], 65.8 - 86.0%) and 94.3% (181/192; 95% CI, 90.0 - 97.1%), respectively. Although some rarely isolated NTM species are misidentified, the most commonly isolated NTM species, including M. avium complex, M. abscessus subsp. abscessus, M. abscessus subsp. massiliense, and M. fortuitum com-plex, were all correctly identified. Of note, all M. lentiflavum strains tested (reference strain, n = 1; clinical strain, n = 10) were misidentified as M. gordonae. CONCLUSIONS: MolecuTech REBA Myco-ID using HybREAD480 was accurate for identifying commonly isolated NTM species and for discriminating between M. abscessus subsp. abscessus and M. abscessus subsp. massiliense. However, the main limitations of this assay, including misidentification of some rarely isolated NTM species and cross-reactivity between M. lentiflavum and M. gordonae, should be considered.

Performance Evaluation of the BACTEC MGIT 960 System for Rifampin Drug-Susceptibility Testing of Mycobacterium tuberculosis Using the Current WHO Critical Concentration.

The World Health Organization recently lowered the rifampin (RIF) critical concentration (CC) for drug-susceptibility testing (DST) of Mycobacterium tuberculosis complex (MTBC) using the mycobacterial growth indicator tube (MGIT) 960 system. Here, we evaluated the diagnostic performance of the MGIT system with the revised CC for determining MTBC RIF resistance with 303 clinical MTBC isolates, including 122 isolates with rpoB mutations, of which 32 had single borderline-resistance mutations, and 181 wild-type rpoB isolates. The phenotypic RIF resistance was determined via the absolute concentration method (AC) and via MGIT using both previous (1 mg/L) and revised (0.5 mg/L) CCs for the latter method. The diagnostic accuracy of each phenotypic DST (pDST) was assessed based on rpoB genotyping as the reference standard. The overall sensitivity of the AC was 95.1% (95% confidence interval [CI], 89.6 to 98.2%), while the MGIT results with previous and revised CCs were 82.0% (95% CI 74.0 to 88.3%) and 83.6% (95% CI 75.8 to 89.7%), respectively. The 32 MTBC isolates with single borderline-resistance mutations showed a wide range of MICs, and sensitivity was not significantly increased by reducing the MGIT CC. All 181 wild-type rpoB isolates were RIF-susceptible in the AC and with MGIT using the previous CC, whereas 1 isolate was misclassified as RIF-resistant with the revised CC. Our results demonstrate that the overall diagnostic performances of the MGIT DST with the revised RIF CC and previous CC were comparable. A further large-scale study is required to demonstrate the optimal RIF CC for MGIT.

Evolution of Fluconazole Resistance Mechanisms and Clonal Types of Candida parapsilosis Isolates from a Tertiary Care Hospital in South Korea.

We investigated the evolution of fluconazole resistance mechanisms and clonal types of Candida parapsilosis isolates from a tertiary care hospital in South Korea. A total of 45 clinical isolates, including 42 collected between 2017 and 2021 and 3 collected between 2012 and 2013, were subjected to antifungal susceptibility testing, sequencing of fluconazole resistance genes (ERG11, CDR1, TAC1, and MRR1), and microsatellite typing. Twenty-two isolates carried Y132F (n = 21; fluconazole MIC = 2 to >256 mg/L) or Y132F+R398I (n = 1; fluconazole MIC = 64 mg/L) in ERG11 and four isolates harbored N1132D in CDR1 (fluconazole MIC = 16 to 64 mg/L). All 21 Y132F isolates exhibited similar microsatellite profiles and formed a distinct group in the dendrogram. All four N1132D isolates displayed identical microsatellite profiles. Fluconazole MIC values of the Y132F isolates varied depending on their MRR1 mutation status (number of isolates, year of isolation, and MIC): K177N (n = 8, 2012 to 2020, 2 to 8 mg/L); K177N + heterozygous G982R (n = 1, 2017, 64 mg/L); K177N + heterozygous S614P (n = 2, 2019 to 2020, 16 mg/L); and K177N + homozygous S614P (n = 10, 2020 to 2021, 64 to > 256 mg/L). Our study revealed that Y132F in ERG11 and N1132D in CDR1 were the major mechanisms of fluconazole resistance in C. parapsilosis isolates. Furthermore, our results suggested that the clonal evolution of Y132F isolates persisting and spreading in hospital settings for several years occurred with the acquisition of heterozygous or homozygous MRR1 mutations associated with a gradual increase in fluconazole resistance.

Comparison between the STANDARD™ F S. Pneumoniae Ag FIA and BinaxNOW S. Pneumoniae Antigen Card for Detection of Streptococcus Pneumoniae Urinary Antigen.

We compared the performance of STANDARD F S. pneumoniae Ag FIA with that of BinaxNOW S. pneumoniae Antigen Card using 206 urine samples. The performance of STANDARD F was highly comparable to that of BinaxNOW. STANDARD F assay could be a valuable tool for diagnosis of invasive pneumococcal disease.

Fatal Prototheca zopfii Algaemia in a Patient with Acute Lymphoblastic Leukemia: a Case Report.

BACKGROUND: Prototheca algaemia is a rare but life-threatening disease that occurs primarily in immunocompromised patients. We report a fatal case of Prototheca zopfii bloodstream infection in a 54-year-old woman receiving chemotherapy for relapsed acute lymphoblastic leukemia. METHODS: The isolate was identified using an automated biochemical identification system (VITEK 2; bioMerieux) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (VITEK MS; bioMerieux). Partial 18S and 28S rDNA sequencing was performed for definitive identification and genotyping. RESULTS: The patient had persistent neutropenic fever, and isolates from blood culture were identified as P. zopfii. Sequencing was performed and the isolate was confirmed to be P. zopfii genotype 2, which was newly named as P. bovis. The patient was treated with liposomal amphotericin B but died of septic shock. CONCLUSIONS: Prototheca spp. should be considered an emerging pathogen, especially in immunocompromised patients, due to its ubiquitous nature.

Evaluation of molecular methods for plasma detection of EGFR mutations in non-small cell lung cancer.

AIM: Epidermal growth factor receptor (EGFR) mutations are detected in non-small cell lung cancer (NSCLC) and associated with responses to therapy with tyrosine kinase inhibitors (TKIs). We compared the analytical performances of two real-time PCRs and droplet digital PCR (ddPCR) to detect EGFR mutations using plasma. METHODS: Plasma EGFR tests were performed using 86 plasma samples from 75 prospectively enrolled NSCLC patients with early and advanced stages. Analytical performances of plasma-using two real-time PCR, Cobas EGFR mutation v2 and PANAMutyper, EGFR kit, and ddPCR were evaluated based on the tissue EGFR test results. The frequencies of EGFR mutations and acquired T790M mutation after TKI therapy were also assessed. RESULTS: The incidence of all EGFR mutations was 52.3% (23/44) in tissue and was up to 43.2% (19/44) in plasma. The Cobas detection rates of three EGFR mutations (exon 19 deletions, L858R, and T790M) in plasma were similar to those in tissue. The Cobas showed a higher detection rate (76.7%) than that by the PANAMutyper (60.5%). Sensitivity for T790M mutation was lower than the sensitivity for the exon 19 deletions or L858R in both tests. Mutant allele frequency measured by ddPCR was significantly correlated with the semi-quantitative values of the Cobas. CONCLUSIONS: Plasma EGFR tests showed similar detection rates for common EGFR mutations compared to the tissue EGFR tests. Cobas showed higher sensitivity in detection of EGFR mutations in body fluids than the PANAMutyper. Real-time PCR using plasma or body fluids could be a suitable first test for the detection of EGFR mutations.

Overexpression of miR-150 Inhibits the NF-κB Signal Pathway in Intervertebral Disc Degeneration through Targeting P2X7.

OBJECTIVE: To elaborate the mechanism of miR-150 in the regulation of the NF-κB signal pathway in intervertebral disc degeneration (IDD) by targeting P2X7. METHODS: The degenerative and normal intervertebral disc tissues were collected to detect the expressions of miR-150 and P2X7. Nucleus pulposus cells were transfected and divided into different groups. Cell apoptosis was determined by flow cytometry and TUNEL staining. The expressions of IL-6, TNF-α, MMP-3, MMP-13, Cox-2, iNOS, collagen II and aggrecan, as well as NF-κB-associated proteins were measured by qRT-PCR and Western blotting. Furthermore, IDD rat models were established to validate the role of miR-150 in vivo. RESULTS: miR-150 was down-regulated but P2X7 was up-regulated in the degenerative intravertebral disc tissues. The apoptosis of nucleus pulposus cells in the IL-1ß-induced group with the transfection of miR-150 mimic and siP2X7 was significantly decreased, with reduced levels of IL-6, TNF-α, MMP-3, MMP-13, Cox-2 and iNOS, increased levels of collagen II and aggrecan, as well as decreased P2X7, p-p65/p65 and cleaved caspase-3. However, the above factors showed an opposite tendency after treatment with miR-150 inhibitor. Furthermore, the P2X7 siRNA transfection could reverse the effects caused by miR-150 inhibitor. Simultaneously, pcDNA P2X7 transfection also inhibited the function of miR-150 mimic in IL-1ß-induced nucleus pulposus cells. In vivoexperiments further verified the protective role of miR-150 in IDD rats. CONCLUSION: miR-150 may alleviate the degeneration of the intervertebral disc partially since it could restrict the NF-κB pathway by targeting P2X7, and thereby inhibiting IL-1ß-induced matrix catabolism, inflammatory responses and apoptosis of the nucleus pulposus cells.

Effects of different interventions on animal models of ischemic stroke: Protocol for an overview and a network meta-analysis.

BACKGROUND: Ischemic stroke often leads to lifelong disability or death in stroke patients. It is one of the most common causes of death and disability worldwide, so it is a global health problem. The objective of this protocol is to provide the methods for using overview and network meta-analysis to identify the more effective intervention for infarct volume and neurobehavioral score in animal models of ischemic stroke. METHODS: A systematic literature search will be conducted in PubMed and Embase to obtain relevant systematic reviews on December 11, 2018. Assessing the Methodological Quality of Systematic Reviews (AMSTAR2) and SYRCLE's risk of bias tool will be used to assess quality of the included reviews and risk of bias of randomized controlled trials (RCTs) for animal studies. Infarct volume and neurobehavioral score will be chosen as primary and secondary outcomes. The relative effect size of the treatment will be calculated using the standardized mean difference (SMD) and 95% confidence interval (CI). R 3.5.1 through the GEMTC package will be used to perform a network meta-analysis to synthesize direct and indirect evidence. RESULTS: The results of this paper will be submitted to a peer-reviewed journal for publication. CONCLUSION: Our study can provide a reference for further clinical practice and can be compared with clinical trial results to obtain a more credible therapeutic effect of this intervention. ETHICS AND COMMUNICATION: Formal ethical approval is unnecessary, because this study is based on published researches. PROSPERO REGISTRATION NUMBER: CRD42019126811.

Evaluation of the Elecsys Syphilis electrochemiluminescence immunoassay as a first-line screening test in the reverse algorithms for syphilis serodiagnosis.

OBJECTIVES: With the development of the automated treponemal test, new syphilis serodiagnosis algorithms, reverse algorithm, and European Centre for Disease Prevention and Control (ECDC) algorithm have been recommended recently. We investigated the efficacy of an electrochemiluminescence immunoassay (ECLIA) as an initial screening test in the reverse and ECDC algorithms. METHODS: Samples from 4,771 subjects were included in this study. We performed rapid plasma reagin (RPR), ECLIA, and Treponema pallidum particle agglutination (TPPA) according to these three algorithms. The fluorescent treponemal antibody absorbed (FTA-ABS) test was additionally applied for discordant cases between the RPR and ECLIA results. The FTA-ABS results and the consensus of three algorithms were considered a gold standard. RESULTS: A total of 208 subjects were diagnosed with syphilis. The traditional algorithm had a sensitivity of 25.96%, specificity of 100%, and accuracy of 96.77%. Both the reverse and ECDC algorithms showed the same diagnostic performance, sensitivity of 95.19%, specificity of 99.96%, and accuracy of 99.75%. The agreements between the traditional algorithm and the other algorithms were 96.9% with a kappa value of 0.415. CONCLUSIONS: The diagnostic accuracy of the reverse and ECDC algorithms using the ECLIA as a first-line screening test was superior to that of the traditional algorithm.

Biliary Taeniasis with Cholecystitis: An Unusual Case of Taenia solium Infection with a Literature Review.

Taeniasis is a cosmopolitan helminthic disease caused by Taenia species, which included Taenia solium, Taenia saginata, and Taenia asiatica. These parasites typically infect the small intestine, but cases of aberrant migration have been reported. We treated a 70-year-old man who presented with vomiting and colicky abdominal pain. On physical examination, Murphy's sign was positive, and laboratory findings indicated severe inflammation. Computed tomography and magnetic resonance cholangiopancreatography revealed typical features of cholecystitis. An 82-cm-long, slender and degenerated, parasite-like organism was aspirated through a percutaneous transhepatic gallbladder drainage tube. After extensive washing of the organism, we detected yellowish-brown colored, spherical 37.9 × 33.8-µm-sized taenid eggs with thick transverse striations. Hematoxylin-eosin-stained worm sections also contained Taeniidae eggs. Polymerase chain reaction amplification of DNA extracted from the worm with species-specific cytochrome c1 (cox1) primer sets detected a T. solium-specific fragment. Because of sustained high fever combined with inflammatory signs, the patient underwent laparoscopic cholecystectomy and inflamed gallbladder removal. A histopathologic specimen demonstrated chronic reactive cholecystitis. The patient's fever and leukocytosis rapidly resolved after surgery. We experienced an uncommon case of biliary taeniasis representing cholecystitis caused by adult worm of T. solium.

Urine Cotinine level with smoking history predicts a risk of coronary artery calcification.

We investigated whether urine cotinine level, alone or combined with smoking status and cumulative smoking amount, could predict coronary calcium (CAC) score increase over time. The study population included 10,980 subjects. We analysed an association between CAC score increase over time and single or combined smoking-related factors. Urine cotinine level of ≥100 ng/mL, current or ex-smokers, and cumulative smoking amount of ≥1 pack-years (PY) showed significantly higher odds ratios (ORs) for CAC score increase over time. A combination of current smokers with >10 PY and urine cotinine level of ≥100 ng/mL showed the highest OR. Irrespective of smoking status and cumulative smoking amount, all combinations with urine cotinine of ≥100 ng/mL showed higher ORs than other combinations with urine cotinine level of <100 ng/mL. Urine cotinine levels can be useful to predict coronary artery calcification and encourage smokers to quit smoking.

Evaluation of the URiSCAN 2 ACR Strip to estimate the urine albumin/creatinine ratios.

BACKGROUND: The urine albumin/creatinine ratio (ACR) test is used to screen patients with chronic diseases, such as diabetes, hypertension and cardiovascular diseases that put them at an increased risk of developing kidney disease. Here, we evaluated the performance of the URiSCAN 2 ACR Strip (URiSCAN; YD diagnostics, Yongin, Korea), a semiquantitative point-of-care testing (POCT) assay, and we compared to an existing POCT assay and a quantitative assay. MATERIALS AND METHODS: A total of 1,020 random urine specimens were analyzed using the semiquantitative URiSCAN 2 ACR Strip and semiquantitative CLINITEK Microalbumin 2 Strip (CLINITEK; Siemens, New York, USA). We evaluated the precision of the URiSCAN 2 ACR Strip and compared the results of the ACR obtained from URiSCAN to those of CLINITEK with the quantitative results of a quantitative assay as a reference. RESULTS: The precision evaluation of the URiSCAN revealed a range between the cutoff (C50 )-20% and C50 +20% bounds, the C5 -C95 interval, with 85.8% confidence. URiSCAN and CLINITEK showed sensitivity and specificity of 87.7% and 72.2%, and 90.2% and 83.0%, respectively. The concordance rates of URiSCAN with CLINITEK and the quantitative assay were 75.6% and 79.1%, respectively. The concordance rate in the abnormal range (≥30 mg/g) between URiSCAN and the quantitative assay were higher than that between CLINITEK and the quantitative assay (78.8% vs 75.4%). CONCLUSIONS: URiSCAN showed good precision and comparable sensitivity with lower specificity than those of CLINITEK.

Design and application of teaching and examination system based on Delphi for obstetric nurse / 医疗卫生装备

Objective To develop a teaching and examination system based on Delphi for the obstetric nurse. Methods The teaching materials were collected for the obstetric nurse, the teaching and examination mode was analyzed, and Delphi was used for programming and MySQL database was applied to teaching and examination data. Results The system had easy operation, high stability and rapid response to the database, and could meet the requirements for the teaching and examination of the trainee nurse. Conclusion The system realizes informatization and high expansibility of obstetric teaching and examination, and thus is worthy promoting practically.

Analysis of 25-Hydroxyvitamin D Status According to Age, Gender, and Seasonal Variation.

BACKGROUND: The effects of age, gender, and seasonal variation on human levels of 25-hydroxyvitamin D (25(OH)D) are not well understood. In this study, we aimed to investigate 25(OH)D status according to these factors in a Korean population. METHODS: A total of 303,943 serum 25(OH)D levels were measured using an electrochemiluminescence immunoassay between October 2011 and May 2014. Potential participants were ineligible for the study if they had significant renal, hepatic, or thyroid dysfunction, as well as any major ongoing disease that could influence serum 25(OH)D levels. RESULTS: A total of 95,137 subjects (49,662 men and 45,475 women) were included in this study. The mean 25(OH)D levels were higher in men (42.4 nmol/l) than in women (32.9 nmol/l, P < 0.001). Among the men and women, 73.0% and 88.9%, respectively, had 25(OH)D levels <50 nmol/l, whereas only 3.8% of men and 1.4% of women had levels >75 nmol/l. The highest mean 25(OH)D value was noted in individuals aged ≥70 for both genders. The proportion of those with 25(OH)D levels <50 nmol/l appeared to be higher among younger subjects (P < 0.001). Lastly, there were significant differences between 25(OH)D levels in individuals during summer to fall and winter to spring in both genders, indicating seasonal periodicity (P < 0.001). CONCLUSIONS: Serum 25(OH)D status varied according to gender, age, and season. Therefore, analyses of vitamin D status require individualized gender, age, and seasonally adjusted thresholds. Clinicians should consider these factors when determining optimal serum 25(OH)D levels in clinical practice.