Characterization of low-density granulocytes in COVID-19.

Severe COVID-19 is characterized by extensive pulmonary complications, to which host immune responses are believed to play a role. As the major arm of innate immunity, neutrophils are one of the first cells recruited to the site of infection where their excessive activation can contribute to lung pathology. Low-density granulocytes (LDGs) are circulating neutrophils, whose numbers increase in some autoimmune diseases and cancer, but are poorly characterized in acute viral infections. Using flow cytometry, we detected a significant increase of LDGs in the blood of acute COVID-19 patients, compared to healthy controls. Based on their surface marker expression, COVID-19-related LDGs exhibit four different populations, which display distinctive stages of granulocytic development and most likely reflect emergency myelopoiesis. Moreover, COVID-19 LDGs show a link with an elevated recruitment and activation of neutrophils. Functional assays demonstrated the immunosuppressive capacities of these cells, which might contribute to impaired lymphocyte responses during acute disease. Taken together, our data confirms a significant granulocyte activation during COVID-19 and suggests that granulocytes of lower density play a role in disease progression.

A comprehensive assessment of four whole blood stabilizers for flow-cytometric analysis of leukocyte populations.

Though cryopreservation of cell fractions is widely used in flow cytometry studies, whole blood cryopreservation is more challenging due to the presence of erythrocytes and effects of fixatives commonly used for preservation. Here, we evaluated and compared head-to-head the performance of four commercial whole blood cryopreservation kits; (1) Cytodelics, (2) Stable-Lyse V2 and Stable-Store V2 (SLSS-V2), (3) Proteomic stabilizer (PROT-1), and (4) Transfix. We found that PROT-1, Transfix, and Cytodelics maintained the distribution of major leukocyte subsets-granulocytes, T cells, natural killer cells, and B cells, on a comparable level to unpreserved samples, despite the attenuation of fluorescence intensities in flow cytometric assays. Moreover, these three stabilizers also maintained the activated phenotypes of neutrophils upon stimulation with N-formylmethionyl-leucyl-phenylalanine and lipopolysaccharides. The upregulation of adhesion molecules (CD11b), Fc receptors (CD16), and granule proteins (CD66b), as well as the shedding of surface L-selectin (CD62L), was conserved most efficiently in PROT-1 and Cytodelics when compared to samples only treated with erythrocyte lysing. However, none of the stabilizers provided a reliable detection of CCR7 for accurate quantification of T cell maturation stages. We also evaluated the performance of Cytodelics in longitudinal clinical samples obtained from acute COVID-19 patients, where it allowed reliable detection of lymphopenia and granulocyte expansion. These results support the feasibility of whole blood cryopreservation for immunophenotyping by flow cytometry, particularly in longitudinal studies. In conclusion, the performance of different stabilizers is variable and therefore the choice of stabilizers should depend on cell type of interest, as well as antibody clones and experimental design of each study.

Determinants of adherence and consequences of the transition from adolescence to adulthood among young people with severe haemophilia (TRANSHEMO): A multicentric French national observational cross-sectional study based on the FranceCoag registry.

INTRODUCTION: It is necessary to gain insights into adherence to healthcare in people with severe haemophilia (PwSH), especially during the transition from paediatric to adult care, which is an important phase in lives of young people with childhood chronic disease. This adherence can be considered as a marker of successful transition. OBJECTIVES: The main objective of the quantitative phase of the TRANSHEMO project was to compare the adherence to healthcare between adolescents and young adults (YAs) with severe haemophilia. The secondary objective was to identify the determinants (facilitators and barriers) of this adherence and associations between these determinants. METHODS: A multicentre, observational, cross-sectional study was conducted in 2017-2019 on PwSH aged between 14 and 17 years (adolescents) or between 20 and 29 years (YAs), included in the FranceCoag registry and having completed the questionnaires. The adherence to healthcare (treatment regimens and clinical follow-up) was compared between adolescents and YAs using the chi-squared test. The determinants of this adherence were analysed by structural equation modelling. RESULTS: There were 277 participants, 107 adolescents, and 170 YAs. The rate of adolescents adhering to healthcare was 82.2%, while the rate of YAs was 61.2% (p < .001). The barriers to the adherence to healthcare were being YA, having repeated at least one school grade and presenting mental health concerns. CONCLUSION: Adolescents had better adherence to healthcare than YAs. According to the determinants enlightened in this project, targeted supportive strategies and adapted therapeutic education programs can be developed for young PwSH to facilitate their adherence to healthcare.

3-OH Phloretin Inhibits High-Fat Diet-Induced Obesity and Obesity-Induced Inflammation by Reducing Macrophage Infiltration into White Adipose Tissue.

Phloretin and its glycoside phlorizin have been reported to prevent obesity induced by high-fat diet (HFD), but the effect of 3-OH phloretin, a catechol metabolite of phloretin, has not been investigated. In this study, we investigated the anti-obesity effects of phloretin and 3-OH phloretin in HFD-fed mice. The body weight gain induced by HFD was more inhibited by administration of 3-OH phloretin than by phloretin. The increases in fat mass, white adipose tissue (WAT) weight, adipocyte size, and lipid accumulation by HFD were also remarkably inhibited by 3-OH phloretin and, to a lesser extent, by phloretin. The HFD-induced upregulation of chemokines and pro-inflammatory cytokines was suppressed by 3-OH phloretin, preventing M1 macrophages from infiltrating into WAT and thereby reducing WAT inflammation. 3-OH phloretin also showed a more potent effect than phloretin on suppressing the expression of adipogenesis regulator genes, such as PPARγ2, C/EBPα, FAS, and CD36. Fasting blood glucose and insulin levels increased by HFD were diminished by the administration of 3-OH phloretin, suggesting that 3-OH phloretin may alleviate obesity-induced insulin resistance. These findings suggested that 3-OH phloretin has the potential to be a natural bioactive compound that can be used in the prevention or treatment of obesity and insulin resistance.

Effect of Plasma Exchange Treatment in Patients with Hypertriglyceridemia-Induced Acute Pancreatitis.

Background and Objectives: To describe the clinical and biological characteristics of patients with hypertriglyceridemia-induced acute pancreatitis (HTG-AP) and to evaluate the effectiveness of therapeutic plasma exchange (TPE) in the management of HTG-AP. Materials and Methods: A cross-sectional study was conducted on 81 HTG-AP patients (30 treated with TPE and 51 treated conventionally). The main outcome was a decrease in serum triglyceride levels (<11.3 mmol/L) within 48 h of hospitalization. Results: The mean age of participants was 45.3 ± 8.7 years, and 82.7% were male. Abdominal pain was the most frequent clinical sign (100%), followed by dyspepsia (87.7%), nausea or vomiting (72.8%), and a bloated stomach (61.7%). The HTG-AP patients treated with TPE had significantly lower calcemia and creatinemia levels but higher triglyceride levels than those who received conservative treatment. They also had more severe diseases than those treated conservatively. All patients in the TPE group were admitted to the ICU, whereas the ICU admission rate in the non-TPE group was 5.9%. The TPE patients were more likely to experience a rapid decrease in triglyceride levels within 48 h of treatment than those treated conventionally (73.3% vs. 49.0%, p = 0.03, respectively). The decrease in triglyceride levels did not depend on the age, gender, or comorbidities of the HTG-AP patients or the severity of disease. However, TPE and early treatment in the first 12 h of disease onset were effective in rapidly reducing serum triglyceride levels (adjusted OR = 3.00, p = 0.04 and aOR = 7.98, p = 0.02, respectively). Conclusions: This report demonstrates the effectiveness of early TPE in reducing triglyceride levels among HTG-AP patients. More randomized clinical trials studies with a large sample size and post-discharge follow-up are needed to confirm the effectiveness of TPE methods in managing HTG-AP.

Functional diversity of isoprenoid lipids in Methylobacterium extorquens PA1.

Hopanoids and carotenoids are two of the major isoprenoid-derived lipid classes in prokaryotes that have been proposed to have similar membrane ordering properties as sterols. Methylobacterium extorquens contains hopanoids and carotenoids in their outer membrane, making them an ideal system to investigate the role of isoprenoid lipids in surface membrane function and cellular fitness. By genetically knocking out hpnE and crtB we disrupted the production of squalene and phytoene in M. extorquens PA1, which are the presumed precursors for hopanoids and carotenoids respectively. Deletion of hpnE revealed that carotenoid biosynthesis utilizes squalene as a precursor resulting in pigmentation with a C30 backbone, rather than the previously predicted canonical C40 phytoene-derived pathway. Phylogenetic analysis suggested that M. extorquens may have acquired the C30 pathway through lateral gene transfer from Planctomycetes. Surprisingly, disruption of carotenoid synthesis did not generate any major growth or membrane biophysical phenotypes, but slightly increased sensitivity to oxidative stress. We further demonstrated that hopanoids but not carotenoids are essential for growth at higher temperatures, membrane permeability and tolerance of low divalent cation concentrations. These observations show that hopanoids and carotenoids serve diverse roles in the outer membrane of M. extorquens PA1.

Occupational integration of adults with severe haemophilia (INTHEMO): A study based on the FranceCoag registry.

INTRODUCTION: Health of people with severe haemophilia (PwSH) improves thanks to the advancements in haemophilia care, giving them more opportunities in occupational integration. However, there is little literature on the occupational integration of PwSH. OBJECTIVES: The main objective of our study was to assess the occupational integration of PwSH and to compare it with that of the general population. The secondary objective was to study the association between individual characteristics (sociodemographic, clinical and psycho-behavioural) and occupational integration of PwSH. METHODS: A multicentre, non-interventional, cross-sectional study was conducted in 2018-2020 on PwSH, aged over 18 and under 65 years and included in the FranceCoag registry. Measurements included indicators of occupational integration, sociodemographic, clinical and psycho-behavioural characteristics. The indicators of occupational integration were compared with those of the general population, using indirect standardization. The data of the general population were available from the National Institute of Statistics and Economic Studies (INSEE). Determinants of occupational integration were explored using structural equation modelling. RESULTS: Of 1262 eligible people, 588 were included. PwSH had a lower employment rate than the general population (standardized ratio, .85; 95% CI, .77-.94). There were more PwSH at tertiary education level than expected (standardized ratio, 1.38; 95% CI, 1.17-1.61). HIV infection, poor physical health and mental health concerns were associated with a higher risk of unemployment in PwSH. CONCLUSION: Employment rate of PwSH is lower than that of the general population despite their higher education level. Target interventions focusing on determinants of difficult occupational integration could be helpful for PwSH.

Avoidable emergency department visits for rabies vaccination.

BACKGROUND: Administering subsequent doses of rabies vaccine is not a medical emergency and does not require access to emergency department (ED) services. This study reviewed ED visits for rabies postexposure prophylaxis (PEP) to identify avoidable ED visits for subsequent rabies vaccination. METHODS: This retrospective study included patients who received human rabies immune globulin (HRIG) or rabies vaccine at 15 EDs of a multi-hospital health system from 2016 to 2018. All ED visits were classified as initial or non-initial healthcare visits after animal exposure. Emergency department visits for non-initial healthcare were classified as necessary (HRIG administration, worsening symptoms, other emergent conditions, or vaccination during a natural disaster) or avoidable (rabies vaccination only). RESULTS: This study included 145 patients with 203 ED visits (113 initial and 90 non-initial healthcare visits). Avoidable ED visits were identified for 19% (28 of 145) of patients and 66% (59 of 90) of ED visits for non-initial healthcare. Contributing factors for avoidable ED visits were suboptimal ED discharge instructions to return to the ED for vaccination (n = 20 visits) and patients' inability to coordinate outpatient follow-up (n = 17 visits). Patients with previous avoidable ED visits had a 73% probability for unnecessarily returning to the ED for vaccination. The average number of avoidable ED visits observed per patient was 0.41 (95% CI = 0.25 to 0.56). Since the Centers for Disease Control and Prevention reports that 30,000 to 60,000 Americans initiates rabies PEP each year, we estimate that 7500 to 33,600 avoidable ED visits occur for rabies vaccination in the US each year. CONCLUSIONS: One of 5 patients who received rabies PEP in the ED had avoidable ED visits for subsequent rabies vaccination. This study highlights systemic lack of coordination following ED discharge and barriers to accessing rabies vaccine.

Wound characteristics and infiltration with immune globulin for rabies postexposure prophylaxis in the emergency department.

OBJECTIVE: This study described characteristics of wounds caused by animal exposures and evaluated patient factors and wound factors associated with wound infiltration of human rabies immune globulin (HRIG). MATERIALS AND METHODS: This retrospective cohort study evaluated wound characteristics among patients who had visible wounds and received HRIG or rabies vaccine for rabies postexposure prophylaxis (PEP) at 15 emergency departments from May 2016 to June 2018. RESULTS: Of 110 included patients (9 children, 82 adults, and 19 older adults), 21% (n = 23) had ≥2 wounds, and 10% (n = 11) had infected wounds. Twenty-eight (25%) patients had severe wounds, defined as receiving sutures (n = 20) or reaching subcutaneous tissue or bone (n = 20). Wounds were present on upper extremities for 42% (n = 46) of patients, lower extremities for 35% (n = 38), head/face for 3% (n = 3), and in multiple locations for 21% (n = 23). Wounds were < 3 cm in length for 64% (n = 70) of patients. Puncture wounds were present in 60% (n = 66) of patients, abrasions in 45% (n = 49), and lacerations in 38% (n = 42). Among 108 wounds from 82 patients with documented HRIG administration sites, 57% (n = 62) of wounds received HRIG infiltration. Infiltration occurred less frequently for wounds on the face/head/torso (adjusted odds ratio [aOR] = 0.07, 95% confidence interval [CI] = 0.01 to 0.49), wounds on hands/fingers (aOR = 0.20, 95% CI = 0.06 to 0.65), and abrasion-only wounds (aOR = 0.26, 95% CI = 0.08 to 0.80) after adjusting for age. CONCLUSIONS: Upon presentation for rabies PEP, most patients did not have severe wounds and did not require emergency services or complex wound management. Wounds on the face, head, torso, hands, or fingers and abrasions were less likely to receive HRIG infiltration.

Structural and genetic insights into a poly-γ-glutamic acid with in vitro antioxidant activity of Bacillus velezensis VCN56.

Poly-γ­glutamic acid (γ­PGA) produced by Bacillus species is a natural biopolymer, which is widely used in various fields including food, pharmaceuticals, and cosmetics. In this study, the screening of 19 Bacillus isolates derived from traditionally fermented foods revealed that Bacillus velezensis VCN56 was the most potent γ­PGA producer. The maximum concentration of crude γ­PGA was 32.9 ± 1.5 g/L in the PGA-3 medium containing glycerol, citric acid, sodium glutamate, NH4Cl, and starch. The resulting γ-PGA was purified and then characterized by HPLC, FTIR, and 1H-NMR analyses. Molecular weight of purified γ­PGA was estimated to be 98 kDa with a polydisperse index of 2.04. Notably, the pure γ­PGA showed significant in vitro antioxidant scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (72.0 ± 1.5%), hydroxyl (81.0 ± 0.6%), and superoxide (43.9 ± 0.8%) radicals at the concentration of 4 mg/mL. Using whole-genome sequencing, the genetic organization of pgs operon responsible for γ­PGA biosynthesis in B. velezensis VCN56 differs from those in other Bacillus genomes. Further genome analysis revealed metabolic pathways for γ-PGA production and degradation. For the first time, the present study provides a better understanding of γ-PGA with a promising antioxidant activity produced by B. velezensis at the phenotypic, biochemical, and genomic levels, which hold potential applications in the foods, cosmetics, and pharmaceutical industries.

HIV and Syphilis Prevalence Among Transgender Women in Ho Chi Minh City, Vietnam.

Globally, transgender women have higher risk for HIV than the general population and men who have sex with men, but there is little data on this population in Vietnam. In 2015 we conducted a biological and behavioral survey of 205 transgender women in Ho Chi Minh City, Vietnam. Factors associated with HIV and syphilis infection were assessed through multivariable logistic regression models. Median age was 25 years (range 18-64). Overall prevalence was 18.0 % for HIV and 17.6 % for syphilis. Factors independently associated with HIV infection included risky alcohol use [adjusted Odds Ratio (aOR) 3.55, 95 % confidence interval (CI) 1.53-8.21], amphetamine stimulant use (aOR 2.90, 95 % CI 1.27-6.61), sex with male sex workers (aOR 4.73, 95 % CI 1.72-13.0), and history of sex with an adult before the age of 18 years (aOR 2.97, 95 % CI 1.06-8.34). Two factors associated with syphilis infection were HIV infection (aOR 2.37, 95 % CI 1.03-5.45) and condomless anal sex with casual partners (aOR 2.27, 95 % CI 1.03-5.00). In order to address the HIV and syphilis epidemics in Vietnamese transgender women, interventions are needed to make HIV and sexually transmitted infection screening and treatment more accessible.

Learning Gain During a Fast Self-driven Bronchoscopy Simulation Training: A Preliminary Study Comparing Low and High-fidelity Models.

BACKGROUND: Nowadays, there is a growing need for competence in bronchoscopy. However, traditional mentorship-based training presents limitations in learning consistency, subjective evaluation, and patient safety concerns. Simulation-based training has gained attention for its potential to enhance skill acquisition and objective assessment. This study explores the effectiveness of self-driven bronchoscopy simulation training using high-fidelity (HFM) and low-fidelity (LFM) models on novice medical students. METHODS: Medical students without prior bronchoscopy experience were randomly assigned to a self-learn using either HFM or LFM for 4 hours. Pre and posttests were conducted to evaluate the students' knowledge and skill gains with a modified Bronchoscopy Skills and Tasks Assessment Tool. After their test results, students were asked to answer a questionnaire based on a Likert Scale to assess their satisfaction with self-learning. RESULTS: The results revealed significant progression in both groups, but the HFM group outperformed the LFM group in terms of total score, knowledge, skills, and procedure duration. Participant satisfaction with the educational process was generally high in both groups. However, this study has certain limitations, such as a small sample size, a short training period, and the absence of real evaluation in patients. CONCLUSION: This study demonstrates the efficacy of self-driven bronchoscopy simulation training using HFM and LFM of bronchoscopy, with HFM offering superior gain for skill and knowledge. Larger-scale and long-term studies are recommended to further investigate the effectiveness of this self-learning and retention of the bronchoscopy knowledge.

Promising properties of cytochrome P450 BM3 reconstituted from separate domains by split intein.

Recombinant cytochrome P450 monooxygenases possess significant potential as biocatalysts, and efforts to improve heme content, electron coupling efficiency, and catalytic activity and stability are ongoing. Domain swapping between heme and reductase domains, whether natural or engineered, has thus received increasing attention. Here, we successfully achieved split intein-mediated reconstitution (IMR) of the heme and reductase domains of P450 BM3 both in vitro and in vivo. Intriguingly, the reconstituted enzymes displayed promising properties for practical use. IMR BM3 exhibited a higher heme content (>50 %) and a greater tendency for oligomerization compared to the wild-type enzyme. Moreover, these reconstituted enzymes exhibited a distinct increase in activity ranging from 165 % to 430 % even under the same heme concentrations. The reproducibility of our results strongly suggests that the proposed reconstitution approach could pave a new path for enhancing the catalytic efficiency of related enzymes.

Assessing the Impact of Genratest on Women With Recurrent Implantation Failure: A Single-Center Study.

Objective Recurrent implantation failure (RIF) is a significant challenge in assisted reproduction. Genratest has emerged as a potential tool to identify the displaced window of implantation (WOI). This study aimed to evaluate the impact of this test on the pregnancy outcomes of RIF patients. Methods A retrospective analysis was conducted on 143 RIF patients who were categorized into two groups: the personalized embryo transfer (pET, n=69) group and standard embryo transfer (sET, n=74) group. The main measured outcomes were clinical pregnancy, ongoing pregnancy, miscarriage, and live birth rates. Results Genratest effectively diagnoses the displaced WOI in 90% of RIF patients. The pET group exhibited a higher rate of clinical pregnancy (n=36/69, 52.2%) compared to the sET group (n=35/74, 47.3%), but this difference was not statistically significant (p=0.679). Ongoing pregnancy rates were comparable between the pET (n=28/69, 40.6%) and the sET (n=30/74, 40.5%) groups (p=0.996). Live birth rates showed no statistically significant difference between the two groups (n=26/69, 37.7% versus n=22/74, 29.7%, p=0.407). Miscarriage rates were similar in both groups (n=9/69, 13% versus n=11/74, 14.9%, p=0.942). Conclusions pET based on the results of the Genratest did not show a significant improvement in pregnancy outcomes, including clinical pregnancy, ongoing pregnancy, live birth, or miscarriage rates. Further research is needed to identify the role of Genratest in RIF patients.

Correction: Assessing the Impact of Genratest on Women With Recurrent Implantation Failure: A Single-Center Study.

[This corrects the article DOI: 10.7759/cureus.52256.].

Mucosal-Associated Invariant T Cells are not susceptible in vitro to SARS-CoV-2 infection but accumulate into the lungs of COVID-19 patients.

Prolonged T cell lymphopenia is common in COVID-19, caused by SARS-CoV-2. While the mechanisms of lymphopenia during COVID-19 remain elusive, it is especially pronounced in a specialized innate-like T cell population called Mucosal Associated Invariant T cells (MAITs). MAITs has been suggested to express Angiotensin-Converting Enzyme 2 (ACE2), which is the well-known cellular receptor for SARS-CoV-2. However, it is still unclear if SARS-CoV-2 can infect or affect MAIT cells directly. In this study, we performed multicolor flow cytometry on peripheral blood mononuclear cells obtained from COVID-19 patients to assess the frequencies of CD8+Vα7.2+CD161+ MAIT subsets at acute and convalescent disease phases. The susceptibility of MAITs and T cells to direct exposure by SARS-CoV-2 was analysed using cells isolated from healthy donor buffy coats by viability assays, virus-specific RT-PCR, and flow cytometry. In situ lung immunofluorescence was used to evaluate retention of T cells, especially MAIT cells, in lung tissues during acute COVID-19. Our study confirms previous reports indicating that circulating MAITs are activated, and their frequency is declined in patients with acute SARS-CoV-2 infection, whereas an accumulation of MAITs and T cells was seen in the lung tissue of individuals with fatal COVID-19. However, despite a fraction of MAITs found to express ACE2, no evidence for the susceptibility of MAITs for direct infection or activation by SARS-CoV-2 particles was observed. Thus, their activation and decline in the circulation is most likely explained by indirect mechanisms involving other immune cells and cytokine-induced pro-inflammatory environment but not by direct exposure to viral particles at the infection site.

Data on a high electrocatalytic activity of metal-WO3 nanocomposite electrocatalysts for hydrogen evolution reaction.

The data given in this article are related to the research article entitled "High electrocatalytic activity of Rh-WO3 electrocatalyst for hydrogen evolution reaction under the acidic, alkaline, and alkaline seawater electrolytes (N.-A. Nguyen et al., 2023) [1]. In this work, metal-WO3 nanocomposites were synthesized and used as electrocatalysts for hydrogen evolution reaction (HER) performance. The morphology and chemical properties of the prepared metal-WO3 nanocomposites were investigated by using scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) techniques.

CYP102A1 peroxygenase catalyzed reaction via in situ H2O2 generation.

CYP102A1 is a promiscuous bacterial cytochrome P450 (CYP or P450) known for its diverse substrates and comparable activity with human P450 enzymes. The development of CYP102A1 peroxygenase activity can contribute significantly to human drug development and drug metabolite production. Peroxygenase has recently emerged as an alternative to a dependency of P450 on NADPH-P450 reductase and NADPH cofactor and gives more opportunity for practical application. However, the H2O2 dependency also leads to challenges regarding its practical application, in which the excessive H2O2 concentration causes the activation of the peroxygenases. Therefore, we need the optimization of H2O2 production to minimize oxidative inactivation. In this study, we report the CYP102A1 peroxygenase-catalyzed atorvastatin hydroxylation reaction with an enzymatic H2O2 generation using glucose oxidase. Random mutagenesis at the CYP102A1 heme domain was used to generate mutant libraries with high throughput screening of highly active mutants, which can pair with the in situ H2O2 generation. The setup of the CYP102A1 peroxygenase reaction was also possible for other statin drugs and could be developed to produce drug metabolites. We also found a relationship between enzyme inactivation and product formation during the catalytic reaction, supported by enzymatic in situ H2O2 supply. It can be suggested that the low product formation is due to enzyme inactivation.

Production of a major metabolite of niclosamide using bacterial cytochrome P450 enzymes.

Niclosamide has been proposed as a possible candidate for a Covid-19 drug. However, the metabolites of niclosamide are difficult to investigate because they are usually not available commercially or they are quite expensive in the commercial market. In this study, the major metabolite of niclosamide in human liver microsomes (HLMs) was confirmed to be 3-OH niclosamide. Because the production of 3-OH niclosamide using HLMs has a slow turnover rate, a new method of producing niclosamide metabolite with an easier and highly cost-efficient method was thus conducted. Bacterial CYP102A1 (BM3) is one of the bacterial cytochrome P450s (CYPs) from Bacillus megaterium that structurally show similar activities to human CYPs. Here, the BM3 mutants were used to produce niclosamide metabolites and the metabolites were analyzed using high-performance liquid chromatography and LC-mass spectrometry. Among a set of mutants tested here, BM3 M14 mutant was the most active in producing 3-OH niclosamide, the major metabolite of niclosamide. Comparing BM3 M14 and HLMs, BM3 M14 production of 3-OH niclosamide was 34-fold higher than that of HLMs. Hence, the engineering of BM3 can be a cost-efficient method to produce 3-OH niclosamide.