RESUMO
The increasing resistance of various malarial parasite strains to drugs has made the production of a new, rapid-acting, and efficient antimalarial drug more necessary, as the demand for such drugs is growing rapidly. As a major global health concern, various methods have been implemented to address the problem of drug resistance, including the hybrid drug concept, combination therapy, the development of analogues of existing medicines, and the use of drug resistance reversal agents. Artemisinin and its derivatives are currently used against multidrug- resistant P. falciparum species. However, due to its natural origin, its use has been limited by its scarcity in natural resources. As a result, finding a substitute becomes more crucial, and the peroxide group in artemisinin, responsible for the drugs biological action in the form of 1,2,4-trioxane, may hold the key to resolving this issue. The literature suggests that 1,2,4-trioxanes have the potential to become an alternative to current malaria drugs, as highlighted in this review. This is why 1,2,4-trioxanes and their derivatives have been synthesized on a large scale worldwide, as they have shown promising antimalarial activity in vivo and in vitro against Plasmodium species. Consequently, the search for a more convenient, environment friendly, sustainable, efficient, and effective synthetic pathway for the synthesis of 1,2,4-trioxanes continues. The aim of this work is to provide a comprehensive analysis of the synthesis and mechanism of action of 1,2,4-trioxanes. This systematic review highlights the most recent summaries of derivatives of 1,2,4-trioxane compounds and dimers with potential antimalarial activity from January 1988 to 2023.
Assuntos
Antimaláricos , Artemisininas , Compostos Heterocíclicos , Artemisininas/farmacologia , Compostos Heterocíclicos/farmacologia , Plasmodium falciparumRESUMO
Human being's biological processes and psychological activities are jointly connected to the brain. So, the examination of human activity is more significant for the well-being of humans. There are various models for brain activity detection considering neuroimaging for attaining decreased time requirement, increased control commands, and enhanced accuracy. Motor Imagery (MI)-based Brain-Computer Interface (BCI) systems create a way in which the brain can interact with the environment by processing Electroencephalogram (EEG) signals. Human Activity Recognition (HAR) deals with identifying the physiological activities of human beings based on sensory signals. This survey reviews the different methods available for HAR based on MI-EEG signals. A total of 50 research articles based on HAR from EEG signals are considered in this survey. This survey discusses the challenges faced by various techniques for HAR. Moreover, the papers are assessed considering various parameters, techniques, publication year, performance metrics, utilized tools, employed databases, etc. There were many techniques developed to solve the problem of HAR and they are classified as Machine Learning (ML) and Deep Learning (DL)models. At last, the research gaps and limitations of the techniques were discussed that contribute to developing an effective HAR.
The brain plays a key role in connecting human biology and psychology, influencing our everyday activities. Understanding human activity is crucial for improving health and well-being. This study focuses on how the brain communicates with the outside world through brain signals, particularly using a method called Motor Imagery (MI) in Brain-Computer Interface (BCI) systems. These systems analyze brain signals, known as Electroencephalograms (EEGs), to detect and interpret human movements. Human Activity Recognition (HAR) is a field that identifies physical activities based on signals from the body. In this survey, we review 50 studies that use EEG signals to recognize human activities. We explore the different techniques that have been developed to tackle HAR and examine their performance based on factors like accuracy, speed, and tools used. These techniques are mainly classified into two categories: Machine Learning (ML) and Deep Learning (DL). This survey highlights the challenges that HAR systems face in recognizing activities from EEG signals. It also identifies gaps in the research and suggests areas for improvement to create more effective systems in the future. Ultimately, this research aims to help develop better technology for understanding human activity through brain signals, which could have important applications in health care and other areas.
RESUMO
Biofilm formation by Mycobacterium fortuitum causes serious threats to human health due to its increased contribution to nosocomial infections. In this study, the first comprehensive global proteome analysis of M. fortuitum was reported under planktonic and biofilm growth states. A label-free Q Exactive Quadrupole-Orbitrap tandem mass spectrometry analysis was performed on the protein lysates. The differentially abundant proteins were functionally characterized and re-annotated using Blast2GO and CELLO2GO. Comparative analysis of the proteins among two growth states provided insights into the phenotypic switch, and fundamental pathways associated with pathobiology of M. fortuitum biofilm, such as lipid biosynthesis and quorum-sensing. Interaction network generated by the STRING database revealed associations between proteins that endure M. fortuitum during biofilm growth state. Hypothetical proteins were also studied to determine their functional alliance with the biofilm phenotype. CARD, VFDB, and PATRIC analysis further showed that the proteins upregulated in M. fortuitum biofilm exhibited antibiotic resistance, pathogenesis, and virulence. Heatmap and correlation analysis provided the biomarkers associated with the planktonic and biofilm growth of M. fortuitum. Proteome data was validated by qPCR analysis. Overall, the study provides insights into previously unexplored biochemical pathways that can be targeted by novel inhibitors, either for shortened treatment duration or for eliminating biofilm of M. fortuitum and related nontuberculous mycobacterial pathogens. KEY POINTS: ⢠Proteomic analyses of M. fortuitum reveals novel biofilm markers. ⢠Acetyl-CoA acetyltransferase acts as the phenotype transition switch. ⢠The study offers drug targets to combat M. fortuitum biofilm infections.
Assuntos
Biofilmes , Redes e Vias Metabólicas , Mycobacterium fortuitum , Proteoma , Mycobacterium fortuitum/química , Mycobacterium fortuitum/metabolismo , Mycobacterium fortuitum/fisiologia , Mycobacterium fortuitum/ultraestrutura , Microscopia Eletrônica de Varredura , Proteoma/análise , Acetil-CoA C-Acetiltransferase/metabolismo , Percepção de QuorumRESUMO
Acinetobacter baumannii forms robust biofilms, which aid protection against antimicrobials and account for adaptation in hospital settings. Biofilm formation by A. baumannii has worsens the scenario of drug resistance. Therefore, new strategies are required to tackle biofilm-forming multidrug-resistant A. baumannii. The present study investigated compounds with antimicrobials and antibiofilm properties against A. baumannii. Different antimicrobials were selected from available reports. Initially, comparative antimicrobial activity against A. baumannii isolates was assessed. Most potent antimicrobial compounds were further analyzed for time-kill kinetics, biofilm inhibition, and exopolysaccharide (EPS) reduction in their presence and absence. The antibiofilm potentials were also confirmed with SEM analysis. The relative gene expression of the csuE gene and molecular docking was carried out to investigate the molecular mechanism of mature biofilm disruption. The results demonstrated eugenol and geraniol as the most potent inhibitors with MICs of 6.08 mM and 3.24 mM, respectively, with the potential to significantly inhibit growth and EPS production. Complete inhibition of A. baumannii mature biofilms was observed with a maximum of 60.89 mM and 129.6 mM concentrations of eugenol and geraniol, respectively. The SEM analysis and lower expression of the csuE gene showed the effectiveness of potent antibiofilm agents. In-silico docking showed efficient binding of eugenol and geraniol with the csuE protein of archaic pilus. The findings of molecular docking concordant the assumption that these molecules may prevent the assembly of mature pilus, which results in abolished biofilms. In conclusion, the antibiofilm virtues of eugenol and geraniol were elucidated to be used in the future to control the persistence of biofilm-forming drug-resistant A. baumannii.
Assuntos
Acinetobacter baumannii , Acinetobacter baumannii/genética , Eugenol/farmacologia , Simulação de Acoplamento Molecular , Biofilmes , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Farmacorresistência Bacteriana Múltipla/genéticaRESUMO
Biofilm formation by Acinetobacter baumannii is one of the major cause of its persistence in hospital environment. Biofilm phenotypes are more resistant to physical as well as chemical stresses than their planktonic counterparts. The present study was carried in quest of biofilm-associated protein markers and their association with various biological pathways of A. baumannii. The study was designed with an aim to highlight the crucial common factor present in the majority of the A. baumannii strains irrespective of its resistance nature. A label-free proteome comparison of biofilm and planktonic phenotypes of A. baumannii was done using QExactive tandem mass spectrometry. Our investigation suggests key elevation of adhesion factors, acetate metabolism, nutrient transporters, and secretion system proteins are required for biofilm formation in A. baumannii. Elevation of biofilm-associated proteins revealed that biofilm is the unique phenotype with the potential to form robust matrix-embedded colonies and defeat stress condition. Further, core protein markers of biofilm phenotypes could be used as targets for new clinical interventions to combat biofilm-associated infections.
Assuntos
Acinetobacter baumannii , Antibacterianos/farmacologia , Biofilmes , Biologia Computacional , Farmacorresistência Bacteriana Múltipla , Plâncton , ProteômicaRESUMO
Biofilm-forming multidrug-resistant Acinetobacter baumannii has emerged as a global pathogen. This study investigated the impact of biofilm formation by A. baumannii on antimicrobial resistance and prolonged survival under desiccation, which is essential for effective infection control of A. baumannii in hospital settings. Seventy-eight clinical isolates of A. baumannii were identified, and antibiotic susceptibility profiles were assessed. All the isolates were investigated for their biofilm-forming abilities at 24 and 48 h. The biofilm inhibitory concentrations of antibiotics were evaluated for selected biofilm-forming isolates to determine the influence of biofilm on antibiotic tolerance. The impact of biofilm formation on desiccation tolerance was also evaluated for up to 48 days. The results revealed that out of 78 A. baumannii clinical isolates, 83% were MDR and 17% non-MDR. Overall, 79% of isolates formed high biofilm after 24 h. The extent of biofilm formation gets significantly increased after 48 h, and 87% of isolates formed high biofilm. It was observed that eradicating mature biofilm requires up to a thousandfold higher concentration of antibiotics than MICs, and biofilm-forming isolates can survive for a prolonged period under desiccation. In conclusion, our findings revealed that both MDR and non-MDR isolates of A. baumannii could form biofilms on abiotic surfaces. A. baumannii biofilms contribute to endurance in the presence of antimicrobials and desiccation conditions, which are significant trouble for hospital patient care management. The present findings may offer insights for developing preventive measures to tackle biofilm-associated A. baumannii infection.
Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Antibacterianos/farmacologia , Biofilmes , Dessecação , Farmacorresistência Bacteriana , Farmacorresistência Bacteriana Múltipla , Humanos , Testes de Sensibilidade MicrobianaRESUMO
The fatty acid biosynthesis pathway is crucial for the formation of the mycobacterial cell envelope. The fatty acid synthase type-II (FAS-II) components are attractive targets for designing anti-biofilm inhibitors. Literature review, bioinformatics analysis, cloning, and sequencing led to the identification of a novel Mycobacterium fortuitum FAS-II gene MFfabG4 which interacts with mycobacterial proteins involved in biofilm formation. A manually curated M. fortuitum fatty acid biosynthesis pathway has been proposed exploiting functional studies from the Kyoto Encyclopedia of Genes and Genomes and Mycobrowser databases for MFFabG4. M. fortuitum MFfabG4 knockdown strain (FA) was constructed and validated by quantitative polymerase chain reaction. The FA strain displayed unstructured smooth colony architecture, correlating with decreased pathogenicity and virulence. MFfabG4 knockdown resulted in diminished pellicle and attenuated biofilm formation, along with impaired sliding motility, and reduced cell sedimentation. The FA strain showed lowered cell surface hydrophobicity, indicating attenuation in M. fortuitum intracellular infection-causing ability. Stress survival studies showed the requirement of MFfabG4 for survival in a nutrient-starved environment. The results indicate that MFfabG4 maintains the physiology of the cell envelope and is required for the formation of M. fortuitum pellicle and biofilm. The study corroborates the role of MFfabG4 as a pellicle- and biofilm-specific drug target and a potential diagnostic marker for M. fortuitum and related pathogenic mycobacteria.
Assuntos
Mycobacterium fortuitum , Mycobacterium fortuitum/genética , Biofilmes , Virulência , Ácidos GraxosRESUMO
The outer membrane (OM) is an essential component of the Gram-negative bacterial envelope that protects the cells against external threats. To maintain a functional OM, cells require distinct mechanisms to ensure balance of proteins and lipids in the membrane. Mutations in OM biogenesis and/or homeostasis pathways often result in permeability defects, but how molecular changes in the OM affect barrier function is unclear. Here, we seek potential mechanism(s) that can alleviate permeability defects in Escherichia coli cells lacking the Tol-Pal complex, which accumulate excess PLs in the OM. We identify mutations in enterobacterial common antigen (ECA) biosynthesis that re-establish OM barrier function against large hydrophilic molecules, yet did not restore lipid homeostasis. Furthermore, we demonstrate that build-up of biosynthetic intermediates, but not loss of ECA itself, contributes to the rescue. This suppression of OM phenotypes is unrelated to known effects that accumulation of ECA intermediates have on the cell wall. Finally, we reveal that an unusual diacylglycerol pyrophosphoryl-linked lipid species also accumulates in ECA mutants, and might play a role in the rescue phenotype. Our work provides insights into how OM barrier function can be restored independent of lipid homeostasis, and highlights previously unappreciated effects of ECA-related species in OM biology.
Assuntos
Antígenos de Bactérias/genética , Proteínas da Membrana Bacteriana Externa/genética , Membrana Externa Bacteriana/fisiologia , Escherichia coli/genética , Antígenos de Bactérias/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Permeabilidade da Membrana Celular , Parede Celular/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Homeostase , Mutação , Proteínas Periplásmicas/genética , Proteínas Periplásmicas/metabolismoRESUMO
Malaria epidemics represent one of the life-threatening diseases to low-income lying countries which subsequently affect the economic and social condition of mankind. In continuation in the development of a novel series of 1,2,4-trioxanes 13a1-c1, 13a2-c2, and 13a3-c3 have been prepared and further converted into their hemisuccinate derivatives 14a1-c1, 14a2-c2, and 14a3-c3 respectively. All these new compounds were evaluated for their antimalarial activity against multidrug-resistant Plasmodium yoelii nigeriensis in mice by both oral and intramuscular (im) routes. Hydroxy-functionalized trioxane 13a1 showed 80% protection and its hemisuccinate derivative 14a1 showed 100% protection at a dose of 48 mg/kg × 4 days by both routes, which is twice active than artemisinin by oral route.
Assuntos
Antimaláricos/uso terapêutico , Compostos Heterocíclicos/uso terapêutico , Malária/tratamento farmacológico , Plasmodium yoelii/efeitos dos fármacos , Administração Oral , Animais , Antimaláricos/administração & dosagem , Antimaláricos/síntese química , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Compostos Heterocíclicos/administração & dosagem , Compostos Heterocíclicos/síntese química , Injeções Intramusculares , Camundongos , Testes de Sensibilidade ParasitáriaRESUMO
In this study, the effects of agitation, temperature, and pH on biofilm formation by Mycobacterium fortuitum were studied and quantified through response surface modeling. The microtiter plate assay was optimized to achieve conditions favoring maximum mycobacterial biofilm quantification. Optical density (OD) measurement using a crystal violet assay was performed to estimate the amount of biofilm formed. Response surface methodology (RSM) results revealed an R2 value of 96.18%, exhibiting a maximum OD of 2.119 (λ570 nm) at a temperature of 37 °C and pH 7.0, under a static environment. The conditions were experimentally validated. Statistically significant results showed that the maximum biofilm was produced 96 h after mycobacterial inoculation. Thus, the results provide a basis for using RSM as an efficient optimization method for M. fortuitum biofilm assays. This approach can also be incorporated into strategies for screening anti-biofilm compounds, synthetic chemicals, drugs, or inhibitors against pathogenic mycobacteria.
Assuntos
Mycobacterium fortuitum , BiofilmesRESUMO
The outer membrane (OM) of Gram-negative bacteria exhibits unique lipid asymmetry, with lipopolysaccharides (LPS) residing in the outer leaflet and phospholipids (PLs) in the inner leaflet. This asymmetric bilayer protects the bacterium against intrusion of many toxic substances, including antibiotics and detergents, yet allows acquisition of nutrients necessary for growth. To build the OM and ensure its proper function, the cell produces OM constituents in the cytoplasm or inner membrane and transports these components across the aqueous periplasmic space separating the two membranes. Of note, the processes by which the most basic membrane building blocks, i.e. PLs, are shuttled across the cell envelope remain elusive. This review highlights our current understanding (or lack thereof) of bacterial PL trafficking, with a focus on recent developments in the field. We adopt a mechanistic approach and draw parallels and comparisons with well-characterized systems, particularly OM lipoprotein and LPS transport, to illustrate key challenges in intermembrane lipid trafficking. Pathways that transport PLs across the bacterial cell envelope are fundamental to OM biogenesis and homeostasis and are potential molecular targets that could be exploited for antibiotic development.
Assuntos
Membrana Externa Bacteriana/metabolismo , Bactérias Gram-Negativas/metabolismo , Fosfolipídeos/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Transporte Biológico , Homeostase , Proteínas de Membrana Transportadoras/metabolismoRESUMO
Mycobacterium fortuitum has emerged as a nosocomial infectious agent and biofilm formation attributed for the presence of this bacterium in hospital environment. Transposon random mutagenesis was used to identify membrane-proteins for biofilm formation in M. fortuitum. Ten mutants were shortlisted from a library of 450 mutants for examine their biofilm forming ability. Comparative biofilm ability with respect to wild type M. fortuitum ATCC 6841 showed an altered and delayed biofilm formation in one mutant namely, MT721. Sequence analysis revealed mutation in anthranilate phosphoribosyl transferase (MftrpD), which is associated with tryptophan operon. Functional interaction study of TrpD protein through STRING showed its interaction with chorismate utilizing proteins, majorly involved in synthesis of aromatic amino acid and folic acid, suggesting that biofilm establishment and maintenance requires components of central metabolism. Our study indicates important role of MftrpD in establishment and maintenance of biofilm by M. fortuitum, which may further be explored for drug discovery studies against mycobacterial infections.
Assuntos
Biofilmes/crescimento & desenvolvimento , Elementos de DNA Transponíveis/genética , Mutagênese Insercional/genética , Mutação/genética , Mycobacterium fortuitum/genética , Mycobacterium fortuitum/fisiologia , Antranilato Fosforribosiltransferase/química , Antranilato Fosforribosiltransferase/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Ácido Corísmico/metabolismo , Mapeamento de Interação de Proteínas , Estrutura Secundária de ProteínaRESUMO
BACKGROUND: Recent reports reveal the emergence of Escherichia coli isolates harbouring a novel resistance mechanism based on four-amino-acid inserts in PBP3. These organisms concomitantly expressed ESBLs or/and serine-/metallo-carbapenemases and were phenotypically detected by elevated aztreonam/avibactam MICs. OBJECTIVES: The in vitro activities of the investigational antibiotic cefepime/zidebactam and approved antibiotics (ceftazidime/avibactam, ceftolozane/tazobactam, imipenem/relebactam and others) were determined against E. coli isolates harbouring four-amino-acid inserts in PBP3. METHODS: Whole-genome sequenced E. coli isolates (n = 89) collected from a large tertiary care hospital in Southern India (n = 64) and from 12 tertiary care hospitals located across India (n = 25) during 2016-18, showing aztreonam/avibactam MICs ≥1 mg/L (≥4 times the aztreonam epidemiological cut-off) were included in this study. The MICs of antibiotics were determined using the reference broth microdilution method. RESULTS: Four-amino-acid inserts [YRIK (n = 30) and YRIN (n = 53)] were found in 83/89 isolates. Among 83 isolates, 65 carried carbapenemase genes [blaNDM (n = 39), blaOXA-48-like (n = 11) and blaNDM + blaOXA-48-like (n = 15)] and 18 isolates produced ESBLs/class C ß-lactamases only. At least 16 unique STs were noted. Cefepime/zidebactam demonstrated potent activity, with all isolates inhibited at ≤1 mg/L. Comparator antibiotics including ceftazidime/avibactam and imipenem/relebactam showed limited activities. CONCLUSIONS: E. coli isolates concurrently harbouring four-amino-acid inserts in PBP3 and NDM are an emerging therapeutic challenge. Assisted by the PBP2-binding action of zidebactam, the cefepime/zidebactam combination overcomes both target modification (PBP3 insert)- and carbapenemase (NDM)-mediated resistance mechanisms in E. coli.
Assuntos
Aminoácidos , Escherichia coli , Antibacterianos/farmacologia , Compostos Azabicíclicos/farmacologia , Cefepima , Ciclo-Octanos , Escherichia coli/genética , Índia , Testes de Sensibilidade Microbiana , Piperidinas , beta-Lactamases/genéticaRESUMO
The severe acute respiratory syndrome is a viral respiratory infection and commonly called as COVID-19, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). It widely transmitted through direct or indirect contact. Currently, no specific treatment against SARS-CoV-2 are available; only prevention and supportive strategy are the preventive measures. The present review emphasizes the latest research related to COVID-19 and SARS-CoV-2 virus as well as the current status of potential inhibitors identified. Recent interest in SARS-CoV-2 has focused on transmission, symptoms, structure, and its structural proteins that exhibit promising therapeutics targets for rapid identification of potential inhibitors. The quick identification of potential inhibitors and immune-boosting functional food ingredients are crucial to combat this pandemic disease. We also tried to give an overview of the functional food components as a nutritional supplement, which helps in boosting our immune system and could be useful in preventing the COVID-19 and/or to improve the outcome during therapy.
Assuntos
Betacoronavirus , Infecções por Coronavirus , Alimento Funcional , Pandemias , Pneumonia Viral , COVID-19 , Humanos , SARS-CoV-2RESUMO
Acinetobacter baumannii is one of the clinically important nosocomial pathogen that has become resistant to most of the conventional antimicrobials. Biofilms formed by A. baumannii are difficult to eradicate, thereby highlighting the need for new therapeutic options to treat biofilm associated infections. Antimicrobial peptides have recently emerged as new alternatives to conventional antibiotics, but peptides often suffer with drawbacks such as poor proteolytic stability and high cost of production. To tackle these limitations, mimetics based on antimicrobial peptides are usually designed and synthesized. In this study we have designed and synthesized a peptoid based on a minimum amphipathic template of a twelve residue cationic peptide. Antimicrobial evaluation of peptide and peptoid was carried out against biofilm producing A. baumannii strains. Further, proteolytic stability study of these compounds was carried out in human serum and morphological alterations caused by them on A. baumannii were visualized by SEM analysis. In addition, these compounds were found to be non toxic to human erythrocytes at their minimum inhibitory concentrations against A. baumannii strains. Overall results obtained in this study suggest that these compounds might be potential antimicrobial agents against biofilm forming A. baumannii and it may be postulated that their mode of action on A. baumannii is disruption of bacterial cell membrane.
Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Glicinas N-Substituídas/farmacologia , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/fisiologia , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/química , Biofilmes/efeitos dos fármacos , Desenho de Fármacos , Humanos , Glicinas N-Substituídas/análogos & derivadosRESUMO
Biogenesis of the outer membrane (OM) in Gram-negative bacteria, which is essential for viability, requires the coordinated transport and assembly of proteins and lipids, including lipopolysaccharides (LPS) and phospholipids (PLs), into the membrane. While pathways for LPS and OM protein assembly are well-studied, how PLs are transported to and from the OM is not clear. Mechanisms that ensure OM stability and homeostasis are also unknown. The trans-envelope Tol-Pal complex, whose physiological role has remained elusive, is important for OM stability. Here, we establish that the Tol-Pal complex is required for PL transport and OM lipid homeostasis in Escherichia coli. Cells lacking the complex exhibit defects in lipid asymmetry and accumulate excess PLs in the OM. This imbalance in OM lipids is due to defective retrograde PL transport in the absence of a functional Tol-Pal complex. Thus, cells ensure the assembly of a stable OM by maintaining an excess flux of PLs to the OM only to return the surplus to the inner membrane. Our findings also provide insights into the mechanism by which the Tol-Pal complex may promote OM invagination during cell division.
Assuntos
Lipídeos de Membrana/metabolismo , Fosfolipídeos/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Transporte Biológico , Divisão Celular , Membrana Celular/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Homeostase , Lipopolissacarídeos/metabolismo , Transporte Proteico/fisiologiaRESUMO
BACKGROUND: Diarrheagenic Escherichia coli (DEC) signifies as an important etiological agent of moderate-to-severe diarrhea. This study was primarily focused on molecular identification of DEC pathotypes; their association with serogroups and estimates of resistance profiles against different antibiotics regime. METHODS: Five hundred seventy-two stool specimens from diarrhea patients were investigated for DEC pathotypes. Molecular pathotypes were identified by amplification of virulence genes associated with distinct pathotypes followed by sequencing. Diarrhea is a self-limiting disease, however, severity and persistence of infection suggest antibiotic use. Therefore, AST and MIC were determined against common antibiotic regimen. Correlations between molecular pathotypes and serogroups were analyzed by somatic "O" antigen serotyping. RESULTS: The present findings reveal incidence of DEC as an etiological agent up to a level of 21% among all diarrheal age groups. DEC infection rate was higher in children. Enteropathogenic E. coliEPEC, a molecular pathotype of DEC, was found as a predominant pathotype with highest frequency of 13.7%. Two other molecular pathotypes enterotoxigenic E. coli (ETEC) and enteroaggregative E. coli (EAEC) accounted for 5.7% and 1.3%, respectively for all diarrhea incidences. Serological analysis deciphered somatic antigens O26, O2, and O3 as major serogroups identified among EPEC, ETEC, and EAEC pathotypes, respectively. All DEC pathotypes exhibited high levels of antibiotic resistance except for cotrimoxazole and norfloxacin. CONCLUSION: Comprehensive molecular characterization of DEC pathotypes, their incidence estimates, and antibiogram patterns will help in ascertaining better diagnostic and therapeutic measures in management of diarrheal diseases.
Assuntos
Diarreia , Escherichia coli Enteropatogênica/genética , Escherichia coli Enteropatogênica/patogenicidade , Infecções por Escherichia coli/complicações , Genes Virais/genética , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Diarreia/etiologia , Diarreia/genética , Diarreia/microbiologia , Resistência Microbiana a Medicamentos , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , RNA Ribossômico 16S/genética , Estudos Retrospectivos , Sorotipagem , Estatística como Assunto , Adulto JovemRESUMO
An efficient, mild, and expeditious synthetic protocol has been developed for the synthesis of structurally diverse 3-amino-imidazo[1,2-a]pyridines, involving a three-component, one-pot cyclocondensation reaction of 2-aminobenzothiazole/2-aminoazines, ethyl isocyanoacetate/tert-butyl isocyanides, and pyrazole-3(4)-carbaldehyde/substituted aromatic carbonyl compounds in 45 min. using In(OTf)[Formula: see text] as a catalyst in toluene. Mild reaction conditions, high atom economy, operational simplicity, short reaction time, and structural diversity with high product conversion are among the advantages of the present synthetic protocol.
Assuntos
Imidazóis/química , Mesilatos/química , Piridinas/química , Piridinas/síntese química , Catálise , Técnicas de Química Sintética , Química Verde , Água/químicaRESUMO
We report a novel lacZ fusion vector and demonstrate its utility for expression analysis of genes associated with Mycobacterium tuberculosis latent infection. The vector contains E. coli (oriE) and mycobacterial (oriM) origins of replication, a kanamycin resistance gene (Km(r)) as selection marker, and a lacZ reporter gene in fusion with MCS for cloning of upstream regulatory sequence of the desired genes. ß-galactosidase activity of the vector was standardized for expression analysis under latent mycobacterial conditions using Phsp60, a constitutive mycobacterial promoter, utilizing Mycobacterium smegmatis as model organism. Validation of the vector was done by cloning and expression analysis of PhspX (alpha crystalline) and Picl (isocitrate lyase), promoters from two of the genes shown to be involved in M. tuberculosis persistence. Both genes showed appreciable levels of ß-galactosidase expression under hypoxia-induced persistent conditions in comparison to their actively replicating state. Expression analysis of a set of hypothetical genes was also done, of which Rv0628c showed increased expression under persistent conditions. The reported fusion vector and the strategy can be effectively used for short listing and validation of drug targets deduced from various non-conclusive approaches such as bioinformatics and microarray analysis against latent/persistent form of mycobacterial infection.
Assuntos
Perfilação da Expressão Gênica/métodos , Genes Bacterianos , Tuberculose Latente/microbiologia , Mycobacterium tuberculosis/genética , beta-Galactosidase/análise , Fusão Gênica Artificial , Chaperonina 60/genética , Clonagem Molecular , Perfilação da Expressão Gênica/normas , Vetores Genéticos , Regiões Promotoras Genéticas , Origem de Replicação , beta-Galactosidase/genéticaRESUMO
This article reports in silico analysis of methyl isocyanate (MIC) on different key immune proteins against Mycobacterium tuberculosis. The analysis shows that MIC is released in the Bhopal gas tragedy in 1984, which is highly toxic and extremely hazardous to human health. In this study, we have selected immune proteins to perform molecular docking with the help of Autodock 4.0. Results show that the CD40 ligand and alpha5beta1 integrin have higher inhibition compared to plasminogen activator urokinase, human glutathione synthetase, mitogen-activated protein kinase (P38 MAPK 14), surfactant protein-B, -D (SP-D), and pulmonary SP-D. MIC interacted with His-125, Try-146 residue of CD40 ligand and Ala-149, and Arg-152 residue of alpha5beta1 integrin and affects the proteins functioning by binding on their active sites. These inhibitory conformations were energetically and statistically favored and supported the evidence from wet laboratory experiments reported in the literature. We can conclude that MIC directly or indirectly affects these proteins, which shows that survivals of the disaster suffer from the diseases like tuberculosis infection and lung cancer.