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Meyerozyma guilliermondii (Candida guilliermondii) is one of the Candida species associated with invasive candidiasis. With the potential for expressing industrially important enzymes, M. guilliermondii strain SO possessed 99 % proteome similarity with the clinical ATCC 6260 isolate and showed pathogenicity towards zebrafish embryos. Recently, three secreted aspartyl proteinases (SAPs) were computationally identified as potential virulence factors in this strain without in vitro verification of SAP activity. The quantification of Candida SAPs activity in liquid broth were also scarcely reported. Thus, this study aimed to characterize M. guilliermondii strain SO's ability to produce SAPs (MgSAPs) in different conditions (morphology and medium) besides analyzing its growth profile. MgSAPs' capability to cleave bovine serum albumin (BSA) was also determined to propose that MgSAPs as the potential virulence factors compared to the avirulent Saccharomyces cerevisiae. M. guilliermondii strain SO produced more SAPs (higher activity) in yeast nitrogen base-BSA-dextrose broth compared to yeast extract-BSA-dextrose broth despite insignificantly different SAP activity in both planktonic and biofilm cells. FeCl3 supplementation significantly increased the specific protein activity (â¼40 %). The BSA cleavage by MgSAPs at an acidic pH was proven through semi-quantitative SDS-PAGE, sharing similar profile with HIV-1 retropepsin. The presented work highlighted the MgSAPs on fungal cell wall and extracellular milieu during host infection could be corroborated to the quantitative production in different growth modes presented herein besides shedding lights on the potential usage of retropepsin's inhibitors in treating candidiasis. Molecular and expression analyses of MgSAPs and their deletion should be further explored to attribute their respective virulence effects.
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Ácido Aspártico Proteases , Biofilmes , Candidíase , Soroalbumina Bovina , Fatores de Virulência , Fatores de Virulência/metabolismo , Fatores de Virulência/genética , Ácido Aspártico Proteases/metabolismo , Ácido Aspártico Proteases/genética , Candidíase/microbiologia , Soroalbumina Bovina/metabolismo , Biofilmes/crescimento & desenvolvimento , Animais , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Meios de Cultura/química , Candida/patogenicidade , Candida/metabolismo , Candida/genética , Saccharomycetales/metabolismo , Saccharomycetales/patogenicidade , Saccharomycetales/genética , VirulênciaRESUMO
Invasive candidiasis caused by the pathogenic Candida yeast species has resulted in elevating global mortality. The pathogenicity of Candida spp. is not only originated from its primary invasive yeast-to-hyphal transition; virulence factors (transcription factors, adhesins, invasins, and enzymes), biofilm, antifungal drug resistance, stress tolerance, and metabolic adaptation have also contributed to a greater clinical burden. However, the current research theme in fungal pathogenicity could hardly be delineated with the increasing research output. Therefore, our study analysed the research trends in Candida pathogenesis over the past 37 years via a bibliometric approach against the Scopus and Web of Science databases. Based on the 3993 unique documents retrieved, significant international collaborations among researchers were observed, especially between Germany (Bernhard Hube) and the UK (Julian Naglik), whose focuses are on Candida proteinases, adhesins, and candidalysin. The prominent researchers (Neils Gow, Alistair Brown, and Frank Odds) at the University of Exeter and the University of Aberdeen (second top performing affiliation) UK contribute significantly to the mechanisms of Candida adaptation, tolerance, and stress response. However, the science mapping of co-citation analysis performed herein could not identify a hub representative of subsequent work since the clusters were semi-redundant. The co-word analysis that was otherwise adopted, revealed three research clusters; the cluster-based thematic analyses indicated the severeness of Candida biofilm and antifungal resistance as well as the elevating trend on molecular mechanism elucidation for drug screening and repurposing. Importantly, the in vivo pathogen adaptation and interactions with hosts are crucial for potential vaccine development.
International research collaborations have evident its significance in impactful work covering all aspects of Candida pathogenicity. Its current, diverse research was discussed thematically based on the comprehensive scientometric analysis with unidentified hub representatives for subsequent work.
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Candidíase , Vacinas , Animais , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Candida/genética , Candidíase/microbiologia , Candidíase/veterinária , Testes de Sensibilidade Microbiana/veterinária , Virulência , BibliometriaRESUMO
Meyerozyma guilliermondii is a rare opportunistic fungal pathogen that causes deadly invasive candidiasis in human. M. guilliermondii strain SO is a local yeast isolate that possesses huge industrial interests but also pathogenic towards zebrafish embryos. Enolases that bind to human extracellular matrix (ECM) proteins are among the fungal virulence factors. To understand its pathogenicity mechanism down to molecular level, especially in the rare M. guilliermondii, this study aimed to identify and characterize the potentially virulence-associated enolase in M. guilliermondii strain SO using bioinformatics approaches. Profile Hidden-Markov model was implemented to identify enolase-related sequences in the fungal proteome. Sequence analysis deciphered only one (MgEno4581) out of nine sequences exhibited potent virulence traits observed similarly in the pathogenic Candida albicans. MgEno4581 structure that was predicted via SWISS-MODEL using C. albicans enolase (CaEno1; PDB ID: 7vrd) as the homology modeling template portrayed a highly identical motif with CaEno1 that facilitates ECM proteins binding. Amino acid substitutions (D234K, K235A, Y238H, K239D, G243K, V248C and Y254F) in ECM-binding motif of Saccharomyces cerevisiae enolase (ScEno) compared to MgEno4581 and CaEno1 caused changes in motif's surface charges. Protein-protein docking indicated F253 in ScEno only interacted hydrophobically with human plasminogen (HPG). Hydrogen linkages were observed for both MgEno4581 and CaEno1, suggesting a stronger interaction with HPG in the hydrophilic host microenvironments. Thus, our in silico characterizations on MgEno4581 provided new perspectives on its potential roles in candidiasis (fungal-host interactions) caused by M. guilliermondii, especially M. guilliermondii strain SO on zebrafish embryos that mimic the immunocompromised individuals as previously evident.
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Fatores de Virulência , Peixe-Zebra , Animais , Humanos , Fosfopiruvato Hidratase , Interações entre Hospedeiro e Microrganismos , Candida albicansRESUMO
Acute hemolytic transfusion reaction following ABO-incompatible platelet transfusion: two case reports An ideal platelet transfusion should provide ABO identical platelet concentrate, and cross match compatibility is not routinely performed in the standard practices. However, ABO non identical platelet transfusions are not uncommon with the limited resources and short shelf life of platelet concentrate. Though rare, acute hemolytic transfusion reaction (AHTR) may occur following minor ABO-incompatible platelet transfusion. Here, we report two cases of thrombocytopenic patients (one child and one adult) type as Group B RhD positive and received Group O RhD positive platelet transfusions. Both patients experienced an AHTR evidenced by a drop in hemoglobin level, spherocytosis and small agglutinations on the blood film, and positive direct Coombs test. They were treated symptomatically, recovered and discharged well post-event without any morbidity. No anti-B isohemagglutinins titer were done to confirm the high titer of the antibody in the platelet donors. Our cases highlighted the importance of ABO-compatible platelet transfusion, especially to children and those vigilant groups of patients.
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Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Reação Transfusional , Adulto , Criança , Humanos , Transfusão de Plaquetas/efeitos adversos , Plaquetas , Incompatibilidade de Grupos Sanguíneos , Tipagem e Reações Cruzadas Sanguíneas , Anticorpos , Sistema ABO de Grupos SanguíneosRESUMO
Background: Haemolytic transfusion reactions (HTRs) due to anti-A and anti-B antibodies in Group O blood products are rare but potentially fatal. This study aimed to identify the prevalence of high ABO antibody titre and the immunoglobulin (Ig) classes (IgM only or with IgG) and the prevalence of haemolysin antibodies in Group O blood donors. Methods: Plasma from Group O blood donors was tested by using antibody titration at room temperature. Titres ≥ 64 were considered high. The plasma was treated with 0.01 M dithiothreitol (DTT) to determine the presence of IgG antibodies and titre. IgG titres ≥ 64 were considered high. Tests for haemolysis were conducted by mixing the plasma with 3% fresh A1 and B cell suspensions and incubating at 37 °C. The haemolysis was observed macroscopically. Results: Of 311 donors, 238 (76.5%) showed high anti-A and/or anti-B antibody titres. The highest antibody titre obtained was 256. Female and younger donors (< 40 years old) had higher anti-A and anti-B titres. The anti-B titre showed an association with gender (P < 0.001), and was high in female donors (77.8%). Males aged over 50 years old were found to have low mean titre antibodies. Most donors had both IgM and IgG ABO antibodies. The prevalence of haemolysins in our population was 3.5%. Conclusion: Most of our O blood donors had a high ABO antibody titre but a low prevalence of haemolysins. Males aged over 50 years old are the best O donors for preventing HTRs, particularly when mismatch transfusion is required. We recommend a transfusion unit screen for ABO antibody titre in younger female donors (< 40 years old), to prevent the transfusion of high titre O blood products into non-O recipients.
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A new Getah virus (GETV) strain, B254, was isolated from Culex fuscocephalus mosquitoes captured at Mount Ophir, Malaysia, in 2012. Phylogenetic analyses revealed that GETV B254 is distinct from the old Malaysia GETV MM2021 strain but closely related to group IV GETV from Russia (LEIV16275Mag), China (YN12031), and Thailand (GETV/SW/Thailand/2017).
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Alphavirus , Culex , Culicidae , Animais , Malásia/epidemiologia , FilogeniaRESUMO
Due to its thermostability and high pH compatibility, subtilisin is most known for its role as an additive for detergents in which it is categorized as a serine protease according to MEROPS database. Subtilisin is typically isolated from various bacterial species of the Bacillus genus such as Bacillus subtilis, B. amyloliquefaciens, B. licheniformis, and various other organisms. It is composed of 268-275 amino acid residues and is initially secreted in the precursor form, preprosubtilisin, which is composed of 29-residues signal peptide, 77-residues propeptide, and 275-residues active subtilisin. Subtilisin is known for the presence of high and low affinity calcium binding sites in its structure. Native subtilisin has general properties of thermostability, tolerance to neutral to high pH, broad specificity, and calcium-dependent stability, which contribute to the versatility of subtilisin applicability. Through protein engineering and immobilization technologies, many variants of subtilisin have been generated, which increase the applicability of subtilisin in various industries including detergent, food processing and packaging, synthesis of inhibitory peptides, therapeutic, and waste management applications.
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Bacillus , Subtilisina , Subtilisina/genética , Cálcio , Sequência de Aminoácidos , Clonagem Molecular , Bacillus/genéticaRESUMO
The objective of this study is to synthesize neem-silver nitrate nanoparticles (neem-AgNPs) using aqueous extracts of Azadirachta indica A. Juss for malaria therapy. Neem leaves collected from FRIM Malaysia were authenticated and extracted using Soxhlet extraction method. The extract was introduced to 1 mM of silver nitrate solution for neem-AgNPs synthesis. Synthesized AgNPs were further characterized by ultraviolet-visible spectroscopy and the electron-scanning microscopy. Meanwhile, for the anti-plasmodial activity of the neem-AgNPs, two lab-adapted Plasmodium falciparum strains, 3D7 (chloroquine-sensitive), and W2 (chloroquine-resistant) were tested. Red blood cells hemolysis was monitored to observe the effects of neem-AgNPs on normal and parasitized red blood cells. The synthesized neem-AgNPs were spherical in shape and showed a diameter range from 31-43 nm. When compared to aqueous neem leaves extract, the half inhibitory concentration (IC50) of the synthesized neem-AgNPs showed a four-fold IC50 decrease against both parasite strains with IC50 value of 40.920 µg/mL to 8.815 µg/mL for 3D7, and IC50 value of 98.770 µg/mL to 23.110 µg/mL on W2 strain. The hemolysis assay indicates that the synthesized neem-AgNPs and aqueous extract alone do not have hemolysis activity against normal and parasitized red blood cells. Therefore, this study shows the synthesized neem-AgNPs has a great potential to be used for malaria therapy.
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Antimaláricos/química , Azadirachta/química , Extratos Vegetais/química , Nitrato de Prata/química , Antimaláricos/síntese química , Antimaláricos/farmacologia , Química Verde , Humanos , Malária Falciparum/tratamento farmacológico , Nanopartículas/química , Plasmodium falciparum/efeitos dos fármacos , Nitrato de Prata/síntese química , Nitrato de Prata/farmacologiaRESUMO
Candidiasis is a fungal infection caused by Candida spp. especially Candida albicans, C. glabrata, C. parapsilosis and C. tropicalis. Although the medicinal therapeutic strategies have rapidly improved, the mortality rate as candidiasis has continuously increased. The secreted and membrane-bound virulence factors (VFs) are responsible for fungal invasion, damage and translocation through the host enterocytes besides the evasion from host immune system. VFs such as agglutinin-like sequences (Als), heat shock protein 70, phospholipases, secreted aspartyl proteinases (Sap), lipases, enolases and phytases are mostly hydrolases which degrade or interact with the enterocyte membrane components. Candidalysin, however, acts as a peptide toxin to induce necrotic cell lysis. To date, structural studies of the VFs remain underexplored, hindering their functional analyses. Among the VFs, only Sap and Als have their structures deposited in Protein Data Bank (PDB). Therefore, this review scrutinizes the mechanisms of these VFs by discussing the VF-deficient studies of several Candida spp. and their abilities to produce these VFs. Nonetheless, their latest reported sequential and structural analyses are discussed to impart a wider perception of the host-pathogen interactions and potential vaccine or antifungal drug targets. This review signifies that more VFs structural investigations and mining in the emerging Candida spp. are required to decipher their pathogenicity and virulence mechanisms compared to the prominent C. albicans. LAY SUMMARY: Candida virulence factors (VFs) including mainly enzymes and proteins play vital roles in breaching the human intestinal barrier and causing deadly invasive candidiasis. Limited VFs' structural studies hinder deeper comprehension of their mechanisms and thus the design of vaccines and antifungal drugs against fungal infections.
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Candida , Candidíase Invasiva , Animais , Antifúngicos/uso terapêutico , Candida albicans , Candidíase Invasiva/tratamento farmacológico , Candidíase Invasiva/veterinária , Fatores de VirulênciaRESUMO
Metallo-ß-lactamases (MBLs) are class B ß-lactamases from the metallo-hydrolase-like MBL-fold superfamily which act on a broad range of ß-lactam antibiotics. A previous study on BLEG-1 (formerly called Bleg1_2437), a hypothetical protein from Bacillus lehensis G1, revealed sequence similarity and activity to B3 subclass MBLs, despite its evolutionary divergence from these enzymes. Its relatedness to glyoxalase II (GLXII) raises the possibility of its enzymatic promiscuity and unique structural features compared to other MBLs and GLXIIs. This present study highlights that BLEG-1 possessed both MBL and GLXII activities with similar catalytic efficiencies. Its crystal structure revealed highly similar active site configuration to YcbL and GloB GLXIIs from Salmonella enterica, and L1 B3 MBL from Stenotrophomonas maltophilia. However, different from GLXIIs, BLEG-1 has an insertion of an active-site loop, forming a binding cavity similar to B3 MBL at the N-terminal region. We propose that BLEG-1 could possibly have evolved from GLXII and adopted MBL activity through this insertion.
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Bacillus/enzimologia , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Tioléster Hidrolases/química , beta-Lactamases/química , Ampicilina/química , Ampicilina/metabolismo , Proteínas de Bactérias/genética , Sítios de Ligação , Domínio Catalítico , Cristalografia por Raios X , Evolução Molecular , Glutationa/análogos & derivados , Glutationa/química , Glutationa/metabolismo , Simulação de Acoplamento Molecular , Filogenia , Conformação Proteica , Stenotrophomonas maltophilia/enzimologiaRESUMO
Bacterial cellulose (BC) is recognized as a multifaceted, versatile biomaterial with abundant applications. Groups of microorganisms such as bacteria are accountable for BC synthesis through static or agitated fermentation processes in the presence of competent media. In comparison to static cultivation, agitated cultivation provides the maximum yield of the BC. A pure cellulose BC can positively interact with hydrophilic or hydrophobic biopolymers while being used in the biomedical domain. From the last two decades, the reinforcement of biopolymer-based biocomposites and its applicability with BC have increased in the research field. The harmony of hydrophobic biopolymers can be reduced due to the high moisture content of BC in comparison to hydrophilic biopolymers. Mechanical properties are the important parameters not only in producing green composite but also in dealing with tissue engineering, medical implants, and biofilm. The wide requisition of BC in medical as well as industrial fields has warranted the scaling up of the production of BC with added economy. This review provides a detailed overview of the production and properties of BC and several parameters affecting the production of BC and its biocomposites, elucidating their antimicrobial and antibiofilm efficacy with an insight to highlight their therapeutic potential.
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Antibacterianos/farmacologia , Biopolímeros/farmacologia , Celulose/metabolismo , Celulose/farmacologia , Gluconacetobacter xylinus/metabolismo , Antibacterianos/metabolismo , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Biopolímeros/química , Escherichia coli/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Nanocompostos/química , Staphylococcus aureus/efeitos dos fármacosRESUMO
Gold nanoparticles (AuNPs) have been widely explored and are well-known for their medical applications. Chemical and physical synthesis methods are a way to make AuNPs. In any case, the hunt for other more ecologically friendly and cost-effective large-scale technologies, such as environmentally friendly biological processes known as green synthesis, has been gaining interest by worldwide researchers. The international focus on green nanotechnology research has resulted in various nanomaterials being used in environmentally and physiologically acceptable applications. Several advantages over conventional physical and chemical synthesis (simple, one-step approach to synthesize, cost-effectiveness, energy efficiency, and biocompatibility) have drawn scientists' attention to exploring the green synthesis of AuNPs by exploiting plants' secondary metabolites. Biogenic approaches, mainly the plant-based synthesis of metal nanoparticles, have been chosen as the ideal strategy due to their environmental and in vivo safety, as well as their ease of synthesis. In this review, we reviewed the use of green synthesized AuNPs in the treatment of cancer by utilizing phytochemicals found in plant extracts. This article reviews plant-based methods for producing AuNPs, characterization methods of synthesized AuNPs, and discusses their physiochemical properties. This study also discusses recent breakthroughs and achievements in using green synthesized AuNPs in cancer treatment and different mechanisms of action, such as reactive oxygen species (ROS), mediated mitochondrial dysfunction and caspase activation, leading to apoptosis, etc., for their anticancer and cytotoxic effects. Understanding the mechanisms underlying AuNPs therapeutic efficacy will aid in developing personalized medicines and treatments for cancer as a potential cancer therapeutic strategy.
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Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Ouro , Química Verde , Nanopartículas Metálicas , Extratos Vegetais/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Fenômenos Químicos , Diagnóstico por Imagem/métodos , Ouro/química , Humanos , Nanopartículas Metálicas/química , Sistemas de Liberação de Fármacos por Nanopartículas , Compostos Fitoquímicos/química , Extratos Vegetais/química , Nanomedicina Teranóstica/métodosRESUMO
BACKGROUND: The emergence of COVID-19 has devastated many parts of the world. From asymptomatic to symptomatic, the virus causes a wide spectrum of presentations. COVID-19 patients may present with oral manifestations. In Afghanistan, where COVID-19 has severely strained the health care system, much of the population lacks proper oral hygiene. This makes the oral cavity a perfect site for SARS-CoV-2 to manifest clinical signs. CASE PRESENTATION: A 62-year-old male was evaluated in the Dentistry Teaching Clinic of Kabul University of Medical Sciences for a painful erosive lesion on dorsal surface of his tongue. He also complained of fever, cough, and taste alteration. He was referred to Afghan Japan Hospital for COVID-19 testing and tested positive. He was followed on for the treatment of SARS-CoV2. After 2 weeks, the patient tested negative and returned to the dentistry clinic for follow-up. Although there were no other signs of COVID-19, the painful erosive lesion on his tongue persisted. Oral evaluation were performed and the patient was advised to practice good hygiene. After 10 days, we observed an asymptomatic geographic tongue without fever and myalgias and the lesion of dorsal surface of tongue improved from severe condition to moderate. CONCLUSION: In conclusion, patients with suspected or confirmed SARS-CoV-2 should be screened for symptoms and physical findings in the oral mucosa To prevent such an outcome, awareness programs need to be implemented for the diagnosis and management of clinical symptoms among patients.
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COVID-19 , Teste para COVID-19 , Humanos , Japão , Masculino , Pessoa de Meia-Idade , RNA Viral , SARS-CoV-2 , Língua , ÚlceraRESUMO
BACKGROUND: Congenital hypothyroidism is the most common cause of treatable mental impairment and growth retardation in newborns. Early diagnosis requires measurement of serum thyroid-stimulating hormone (TSH) and free T4 coupled with an ultrasound of the thyroid gland. However, detailed sonographic evaluation of the thyroid gland requires comparison to the local thyroid normative volumetric values, which is currently lacking. METHODS: A cross-sectional study was conducted from November 10, 2015, to April 18, 2018, recruiting 165 healthy neonates with normal TSH in their 1st week of life, from a single center in Northwest Malaysia. Ultrasound thyroid was done by a single ultrasonographer (κ = 0.86, percent agreement = 92.4), and the thyroid volume (TV) was calculated using the Brunn formula. RESULTS: All measurements showed skewed distribution with no significant difference between the right and left lobes. The local normative values for neonatal total TV was 0.61 (interquartile range [IQR] = 0.230) cm3, 0.31 (IQR = 0.150) cm3 for right TV, and 0.28 (IQR = 0.110) cm3 for left TV. There was a strong correlation between the right and left TVs, r = 0.767, P < 0.001. There were also no differences in the total TV across different genders and races. CONCLUSION: The normative values for TV determined in our study may be used accordingly in clinical practice to evaluate thyroid hypoplasia or goiter by other Asian countries due to the similarly shared biodemography.
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Global seaport network efficiency can be measured using the Liner Shipping Connectivity Index (LSCI) with Gross Domestic Product. This paper utilizes k-means and hierarchical strategies by leveraging the results obtained from Data Envelopment Analysis (DEA) and Fuzzy Data Envelopment Analysis (FDEA) to cluster 133 countries based on their seaport network efficiency scores. Previous studies have explored hkmeans clustering for traffic, maritime transportation management, swarm optimization, vessel trajectory prediction, vessels behaviours, vehicular ad hoc network etc. However, there remains a notable absence of clustering research specifically addressing the efficiency of global seaport networks. This research proposed hkmeans as the best strategy for the seaport network efficiency clustering where our four newly founded clusters; low connectivity (LC), medium connectivity (MC), high connectivity (HC) and very high connectivity (VHC) are new applications in the field. Using the hkmeans algorithm, 24 countries have been clustered under LC, 47 countries under MC, 40 countries under HC and 22 countries under VHC. With and without a fuzzy dataset distribution, this demonstrates that the hkmeans clustering is consistent and practical to form grouping of general data types. The findings of this research can be useful for researchers, authorities, practitioners and investors in guiding their future analysis, decision and policy makings involving data grouping and prediction especially in the maritime economy and transportation industry.
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Algoritmos , Análise por Conglomerados , Lógica Fuzzy , Meios de Transporte , Navios , HumanosRESUMO
The antiphospholipid syndrome (APS) manifests through venous or arterial thrombosis, with or without pregnancy complication alongside the continuous presence of antiphospholipid antibodies (aPL). APS classification relies on three aPL subtypes: anticardiolipin (aCL), anti-ß2-glycoprotein I antibodies (anti-ß2GPI), and lupus anticoagulants (LA) antibodies. Given that thrombosis and pregnancy issues are not unique to APS, the precise and reliable identification of aPL forms the basis for diagnosis. Semi-quantitative solid-phase assays identify two antibodies, aCL and anti-ß2GPI, while LA detection occurs through various phospholipid-dependent coagulation assays that are based on antibody behaviour. LA, specifically, is conclusively associated with thrombosis, prompting discussions around the serological criteria for APS. Despite advancements in LA detection, the standardisation of all aPL detection assays remains imperative. The combined presence of aCL and anti-ß2GPI with thrombosis inconsistently triggers concern. Initial presentations by APS patients commonly exhibit a heightened risk of stroke, miscarriages in the later stages of pregnancy, positive results of LA tests, and widespread thrombosis across multiple organs, often leading to adverse outcomes. Correctly diagnosing this condition is pivotal to avoid unnecessary long-term secondary thromboprophylaxis.
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Metallo-ß-lactamase (MBL) is an enzyme produced by clinically important bacteria that can inactivate many commonly used antibiotics, making them a significant concern in treating bacterial infections and the risk of having high antibiotic resistance issues among the community. This review presents a bibliometric and patent analysis of MBL worldwide research trend based on the Scopus and World Intellectual Property Organization databases in 2013-2022. Based on the keywords related to MBL in the article title, abstract, and keywords, 592 research articles were retrieved for further analysis using various tools such as Microsoft Excel to determine the frequency analysis, VOSviewer for bibliometric networks visualization, and Harzing's Publish or Perish for citation metrics analysis. Standard bibliometric parameters were analysed to evaluate the field's research trend, such as the growth of publications, topographical distribution, top subject area, most relevant journal, top cited documents, most relevant authors, and keyword trend analysis. Within 10 years, MBL discovery has shown a steady and continuous growth of interest among the community of researchers. United States of America, China, and the United Kingdom are the top 3 countries contribute high productivity to the field. The patent analysis also shows several impactful filed patents, indicating the significance of development research on the structural and functional relationship of MBL for an effective structure-based drug design (SBDD). Developing new MBL inhibitors using SBDD could help address the research gap and provide new successful therapeutic options for treating MBL-producing bacterial infections.
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Infecções Bacterianas , beta-Lactamases , Humanos , beta-Lactamases/química , Antibacterianos/farmacologia , Bibliometria , Desenho de FármacosRESUMO
In this present study, characteristics and structure-function relationship of an organophosphate-degrading enzyme from Bacillus sp. S3wahi were described. S3wahi metallohydrolase, designated as S3wahi-MH (probable metallohydrolase YqjP), featured the conserved αß/ßα metallo-ß-lactamase-fold (MBL-fold) domain and a zinc bimetal at its catalytic site. The metal binding site of S3wahi-MH also preserves the H-X-H-X-D-H motif, consisting of specific amino acids at Zn1 (Asp69, His70, Asp182, and His230) and Zn2 (His65, His67, and His137). The multifunctionality of S3wahi-MH was demonstrated through a steady-state kinetic study, revealing its highest binding affinity (KM) and catalytic efficiency (kcat/KM) for OP compound, paraoxon, with values of 8.09 × 10-6 M and 4.94 × 105 M-1 s-1, respectively. Using OP compound, paraoxon, as S3wahi-MH native substrate, S3wahi-MH exhibited remarkable stability over a broad temperature range, 20 °C - 60 °C and a broad pH tolerance, pH 6-10. Corresponded to S3wahi-MH thermal stability characterization, the estimated melting temperature (Tm) was found to be 72.12 °C. S3wahi-MH was also characterized with optimum catalytic activity at 30 °C and pH 8. Additionally, the activity of purified S3wahi-MH was greatly enhanced in the presence of 1 mM and 5 mM of manganese (Mn2+), showing relative activities of 1323.68 % and 2073.68 %, respectively. The activity of S3wahi-MH was also enhanced in the presence of DMSO and DMF, showing relative activities of 270.37 % and 307.41 %, respectively. The purified S3wahi-MH retained >60 % residual activity after exposure to non-ionic Tween series surfactants. Nevertheless, the catalytic activity of S3wahi-MH was severely impacted by the treatment of SDS, even at low concentrations. Considering its enzymatic properties and promiscuity, S3wahi-MH emerges as a promising candidate as a bioremediation tool in wide industrial applications, including agriculture industry.
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Bacillus , beta-Lactamases , Bacillus/enzimologia , beta-Lactamases/química , beta-Lactamases/metabolismo , Cinética , Especificidade por Substrato , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Domínio Catalítico , Sequência de Aminoácidos , Organofosfatos/metabolismo , Organofosfatos/química , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , TemperaturaRESUMO
Meyerozyma guilliermondii is a rare yeast pathogen contributing to the deadly invasive candidiasis. M. guilliermondii strain SO, as a promising protein expression host, showed 99% proteome similarity with the clinically isolated ATCC 6260 (type strain) in a recent comparative genomic analysis. However, their in vitro virulence features and in vivo pathogenicity were uncharacterized. This study aimed to characterize the in vitro and in vivo pathogenicity of M. guilliermondii strain SO and analyze its Als proteins (MgAls) via comprehensive bioinformatics approaches. M. guilliermondii strain SO showed lower and higher sensitivity towards ß-mercaptoethanol and lithium, respectively than the avirulent S. cerevisiae but exhibited the same tolerance towards cell wall-perturbing Congo Red with C. albicans. With 7.5× higher biofilm mass, M. guilliermondii strain SO also demonstrated 75% higher mortality rate in the zebrafish embryos with a thicker biofilm layer on the chorion compared to the avirulent S. cerevisiae. Being one of the most important Candida adhesins, sequence and structural analyses of four statistically identified MgAls showed that MgAls1056 was predicted to exhibit the most conserved amyloid-forming regions, tandem repeat domain and peptide binding cavity (PBC) compared to C. albicans Als3. Favoured from the predicted largest ligand binding site and druggable pockets, it showed the highest affinity towards hepta-threonine. Non-PBC druggable pockets in the most potent virulence contributing MgAls1056 provide new insights into developing antifungal drugs targeting non-albicans Candida spp. Virtual screening of available synthetic or natural bioactive compounds and MgAls1056 deletion from the fungal genome should be further performed and validated experimentally.Communicated by Ramaswamy H. Sarma.
RESUMO
Aminopeptidase P (APPro) is a crucial metalloaminopeptidase involved in amino acid cleavage from peptide N-termini, playing essential roles as versatile biocatalysts with applications ranging from pharmaceuticals to industrial processes. Despite acknowledging its potential for catalysis in lower temperatures, detailed molecular basis and biotechnological implications in cold environments are yet to be explored. Therefore, this research aims to investigate the molecular mechanisms underlying the cold-adapted characteristics of APPro from Pseudomonas sp. strain AMS3 (AMS3-APPro) through a detailed analysis of its structure and dynamics. In this study, structure analysis and molecular dynamics (MD) simulation of a predicted model of AMS3-APPro has been performed at different temperatures to assess structural flexibility and thermostability across a temperature range of 0-60 °C over 100 ns. The MD simulation results revealed that the structure were able to remain stable at low temperatures. Increased temperatures present a potential threat to the overall stability of AMS3-APPro by disrupting the intricate hydrogen bond networks crucial for maintaining structural integrity, thereby increasing the likelihood of protein unfolding. While the metal binding site at the catalytic core exhibits resilience at higher temperatures, highlighting its local structural integrity, the overall enzyme structure undergoes fluctuations and potential denaturation. This extensive structural instability surpasses the localized stability observed at the metal binding site. Consequently, these assessments offer in-depth understanding of the cold-adapted characteristics of AMS3-APPro, highlighting its capability to uphold its native conformation and stability in low-temperature environments. In summary, this research provides valuable insights into the cold-adapted features of AMS3-APPro, suggesting its efficient operation in low thermal conditions, particularly relevant for potential biotechnological applications in cold environments.Communicated by Ramaswamy H. Sarma.