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1.
Entropy (Basel) ; 24(5)2022 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-35626478

RESUMO

Neurodegenerative disorders involve various pathophysiological pathways, and finding a solution for these issues is still an uphill task for the scientific community. In the present study, a combination of molecular docking and dynamics approaches was applied to target different pathways leading to neurodegenerative disorders such as Alzheimer's disease. Initially, abrineurin natural inducers were screened using physicochemical properties and toxicity assessment. Out of five screened compounds, a pentacyclic triterpenoid, i.e., Soyasapogenol B appeared to be the most promising after molecular docking and simulation analysis. Soyasapogenol B showed low TPSA (60.69), high absorption (82.6%), no Lipinski rule violation, and no toxicity. Docking interaction analysis revealed that Soyasapogenol B bound effectively to all of the targeted proteins (AChE, BuChE MAO-A, MAO-B, GSK3ß, and NMDA), in contrast to other screened abrineurin natural inducers and inhibitors. Importantly, Soyasapogenol B bound to active site residues of the targeted proteins in a similar pattern to the native ligand inhibitor. Further, 100 ns molecular dynamics simulations analysis showed that Soyasapogenol B formed stable complexes against all of the targeted proteins. RMSD analysis showed that the Soyasapogenol B-protein complex exhibited average RMSD values of 1.94 Å, 2.11 Å, 5.07 Å, 2.56 Å, 3.83 Å and 4.07 Å. Furthermore, the RMSF analysis and secondary structure analysis also indicated the stability of the Soyasapogenol B-protein complexes.

2.
J Cell Biochem ; 2021 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-33817826

RESUMO

Leishmaniasis is a neglected tropical disease caused by the protozoan parasite Leishmania. It is endemic in more than 89 different countries worldwide. Sterol alpha-14 demethylase (LdSDM), a sterol biosynthetic pathway enzyme in Leishmania donovani, plays an essential role in parasite survival and proliferation. Here, we used a drug repurposing approach to virtually screen the library of the Food and Drug Administration (FDA)-approved drugs against LdSDM to identify the potential lead-drug against leishmaniasis. Zafirlukast and avodart showed the best binding with LdSDM. Zafirlukast was tested for in vitro antileishmanial assay, but no significant effect on L. donovani promastigotes was observed even at higher concentrations. On the other hand, avodart profoundly inhibited parasite growth at relatively lower concentrations. Further, avodart showed a significant decrease in the number of intra-macrophagic amastigotes. Avodart-induced reactive oxygen species (ROS) in the parasites in a dose-dependent manner. ROS induced by avodart led to the induction of apoptosis-like cell death in the parasites as observed through annexin V/PI staining. Here, for the first time, we reported the antileishmanial activity and its possible mechanism of action of FDA-approved drug, avodart, establishing a nice example of the drug-repurposing approach. Our study suggested the possible use of avodart as an effective antileishmanial agent after further detailed validations.

3.
J Cell Biochem ; 2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-33955051

RESUMO

Leishmaniasis is a neglected tropical disease caused by trypanosomatid parasite belonging to the genera Leishmania. Leishmaniasis is transmitted from one human to other through the bite of sandflies. It is endemic in around 98 countries including tropical and subtropical regions of Asia, Africa, Southern America, and the Mediterranean region. Sterol C-24 methyltransferase (LdSMT) of Leishmania donovani (L. donovani) mediates the transfer of CH3-group from S-adenosyl methionine to C-24 position of sterol side chain which makes the ergosterol different from cholesterol. Absence of ortholog in human made it potential druggable target. Here, we performed virtual screening of library of natural compounds against LdSMT to identify the potential inhibitor for it and to fight leishmaniasis. Gigantol, flavan-3-ol, and parthenolide showed the best binding affinity towards LdSMT. Further, based on absorption, distribution, metabolism, and excretion properties and biological activity prediction, gigantol showed the best lead-likeness and drug-likeness properties. Therefore, we further elucidated its antileishmanial properties. We found that gigantol inhibited the growth and proliferation of promastigotes as well as intra-macrophagic amastigotes. Gigantol exerted its antileishmanial action through the induction of reactive oxygen species in dose-dependent manner. Our study, suggested the possible use of gigantol as antileishmanial drug after further validations to overcome leishmaniasis.

4.
Mol Cell Biochem ; 476(10): 3711-3718, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34089472

RESUMO

Recently calcium homeostasis modulators (CALHMs) are identified as ATP release channels play crucial role in functioning of neurons including gustatory signaling and neuronal excitability. Pathologies of Alzheimer's disease and depression have been associated with the dysfunction of CALHMs. Recently, CALHMs has been emerged as an important therapeutic research particularly in neurobiological studies. CALHM1 is most extensively studied among CALHMs and is an ATP and ion channel that is activated by membrane depolarization or removal of extracellular Ca2+. Despite the emerged role of CALHM5 shown by an recently assembled data; however, the neuronal function remains obscure until the first Cryo-EM structure of CALHM5 was recently solved by various research group which acts as a template to study the hidden functional properties of the CALHM5 protein based on structure function mechanism. It provides insight in some of the different pathophysiological roles. CALHM5 structure showed an abnormally large pore channel structure assembled as an undecamer with four transmembrane helices (TM1-TM4), an N-terminal helix (NTH), an extracellular loop region and an intracellular C-terminal domain (CTD) that consists of three α-helices CH1-3. The TM1 and NTH were always poorly defined among all CALHMs; however, these regions were well defined in CALHM5 channel structure. In this context, this review will provide insight in structure, function and mechanism to understand its significant role in pathological diseases particularly in Alzheimer's disease. Moreover, it focuses on CALHM5 structure and recent associated properties based on Cryo-EM research.


Assuntos
Trifosfato de Adenosina/metabolismo , Doença de Alzheimer/metabolismo , Depressão/metabolismo , Glicoproteínas de Membrana , Potenciais da Membrana , Doença de Alzheimer/patologia , Cálcio/metabolismo , Depressão/patologia , Humanos , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/metabolismo , Conformação Proteica em alfa-Hélice
5.
Drug Dev Res ; 82(8): 1154-1161, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33929761

RESUMO

Leishmaniasis is a vector-borne disease caused by around 20 species of Leishmania. The main clinical forms of leishmaniasis are cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL). VL is caused by Leishmania infantum in Central and South America, Mediterranean Basin, Middle East, and by L. donovani in Asia and Africa. Sterol C-24 methyltransferase (LdSMT) of L. donovani is a transferase enzyme of the sterol biosynthesis pathway. This pathway is one of the major targets for drug developments in Leishmania. Due to insufficient evidence about the exact function of SMT inside the cell and the uniqueness of the SMT enzyme in the Leishmania parasites made it a significant target for an effective drug development approach. We performed virtual screening of the Food and Drug Administration (FDA)-approved drug library against LdSMT and found simeprevir, an antiviral drug on top in the binding score. It showed a significant binding affinity with LdSMT. The binding was supported by hydrogen bonds and several other interactions. Simeprevir inhibited L. donovani growth of promastigotes with 50% inhibitory concentration (IC50 ) of 51.49 ± 5.87 µM. Further studies showed that simeprevir induced ROS generation in 44.7% of parasites at 125-µM concentration. Here, we for the first time reported simeprevir as an antileishmanial lead molecule using a drug repurposing approach.


Assuntos
Reposicionamento de Medicamentos , Leishmania donovani/efeitos dos fármacos , Leishmaniose Visceral/tratamento farmacológico , Metiltransferases/antagonistas & inibidores , Simeprevir/farmacologia , Aprovação de Drogas , Leishmania donovani/enzimologia
6.
Hemoglobin ; 44(1): 47-50, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32091272

RESUMO

Despite the high prevalence of hemoglobinopathies in Saudi Arabia, the prevalence data in some regions are lacking. Updating the epidemiological survey of hemoglobinopathies at regular intervals is necessary to develop effective prevention and control strategies. Therefore, the primary aim of this study was to determine the prevalence of selected hemoglobinopathies in Saudi adults attending premarital screening at the King Khaled General Hospital (KKGH), Al Majma'ah, Saudi Arabia. The current retrospective study was approved by the Central Institutional Review Board (IRB) of the Ministry of Health (with central IRB log #2019-0039E) and was carried out at the above hospital. The data of the premarital couples, who attended the premarital screening center at KKGH from 1 October 2016 to 30 September 2019, was included in this study. A cation exchange high performance liquid chromatography (HPLC) system was used for screening of the selected hemoglobinopathies. In total, 3755 cases including 1953 (52.01%) males and 1802 (47.99%) females, were screened for hemoglobinopathies. Abnormal hemoglobin (Hb) fractions were observed in 38 (1.01%) cases. The prevalence of ß-thalassemia (ß-thal) trait was 0.69% (26/3755) and that of sickle cell trait 0.32% (12/3755). Our results showed that the prevalence of ß-thal trait is higher than that of sickle cell trait in the adult population of Al Majma'ah. Further comprehensive programs should be carried out to determine the prevalence of hemoglobinopathies in various provinces and cities of Saudi Arabia and other countries. This will help to maintain the updated records of the disease incidence for improving the control measures.


Assuntos
Hemoglobina Falciforme/genética , Mutação , Traço Falciforme/epidemiologia , Globinas beta/genética , Talassemia beta/epidemiologia , Adulto , Cromatografia Líquida de Alta Pressão , Feminino , Expressão Gênica , Aconselhamento Genético , Testes Genéticos , Humanos , Masculino , Exames Pré-Nupciais , Prevalência , Estudos Retrospectivos , Arábia Saudita/epidemiologia , Traço Falciforme/sangue , Traço Falciforme/diagnóstico , Traço Falciforme/genética , Globinas beta/deficiência , Talassemia beta/sangue , Talassemia beta/diagnóstico , Talassemia beta/genética
7.
Microb Pathog ; 123: 227-232, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30031038

RESUMO

C. perfringens type F isolates carrying enterotoxin gene (cpe) on the chromosome (C-cpe isolates) are mostly associated with food poisoning, while isolates carrying plasmid-borne cpe (P-cpe isolates) with non-food-borne gastrointestinal diseases. Spore germination is considered the most essential step for initiation of these diseases. Identifying the most effective germinants for spores of C-cpe and P-cpe isolates should help developing novel strategies involving induction of spore germination followed by inactivation of germinated spores with mild treatments. In this study, we showed that (i) l-lysine (pH 6.0) triggered germination of spores of all tested C-cpe and P-cpe isolates; although extremely low concentration of l-lysine (5-10 mM) induced germination of C-cpe spores, 10-fold higher concentration (50 mM) was required for P-cpe spore germination; (ii) P-cpe strain F4969 gerKC spores did not germinate, C-cpe strain SM101 gerKC spores germinated extremely poorly and these gerKC spores released significantly less DPA as compared to wild type spores; and these defects were restored to a nearly wild-type level by complementing gerKC spores with wild-type gerKC; and (iii) F4969 gerAA spores also did not germinate, and released less DPA than wild-type spores in presence of l-lysine (pH 6.0); and these defects were restored partially (germination) and fully (DPA release) by complimenting gerAA spores with wild-type gerAA. Collectively, our current study identified l-lysine as a universal germinant for spores of both C-cpe and P-cpe isolates and provided evidence that GerKC (from SM101 or F4969) and F4969 GerAA play major roles in l-lysine-induced germination.


Assuntos
Cromossomos Bacterianos/genética , Clostridium perfringens/efeitos dos fármacos , Clostridium perfringens/genética , Enterotoxinas/genética , Lisina/farmacologia , Plasmídeos/genética , Esporos Bacterianos/efeitos dos fármacos , Esporos Bacterianos/crescimento & desenvolvimento , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Clostridium perfringens/crescimento & desenvolvimento , Clostridium perfringens/metabolismo , Relação Dose-Resposta a Droga , Doenças Transmitidas por Alimentos , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Genes Bacterianos , Lisina/metabolismo , Ácidos Picolínicos/metabolismo , Esporos Bacterianos/genética , Esporos Bacterianos/metabolismo
8.
Food Microbiol ; 69: 64-71, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28941910

RESUMO

Clostridium perfringens type A isolates carrying a chromosomal enterotoxin (cpe) gene (C-cpe) are generally linked to food poisoning, while isolates carrying cpe on a plasmid (P-cpe) are associated with non-food-borne gastrointestinal diseases. Both C-cpe and P-cpe isolates can form metabolically dormant spores, which through germination process return to actively growing cells to cause diseases. In our previous study, we showed that only 3 out of 20 amino acids (aa) in phosphate buffer (pH 7.0) triggered germination of spores of P-cpe isolates (P-cpe spores). We now found that 14 out of 20 individual aa tested induced germination of P-cpe spores in the presence of bicarbonate buffer (pH 7.0). However, no significant spore germination was observed with bicarbonate (pH 7.0) alone, indicating that aa and bicarbonate are co-germinants for P-cpe spores. P-cpe strain F4969 gerKC spores did not germinate, and gerAA spores germinated extremely poorly as compared to wild-type and gerKA spores with aa-bicarbonate (pH 7.0) co-germinants. The germination defects in gerKC and gerAA spores were partially restored by complementing gerKC or gerAA spores with wild-type gerKC or gerAA, respectively. Collectively, this study identified aa-bicarbonate as a novel nutrient germinant for P-cpe spores and provided evidence that GerKC and GerAA play major roles in aa-bicarbonate induced germination.


Assuntos
Aminoácidos/metabolismo , Bicarbonatos/metabolismo , Clostridium perfringens/metabolismo , Enterotoxinas/metabolismo , Plasmídeos/genética , Esporos Bacterianos/crescimento & desenvolvimento , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Clostridium perfringens/genética , Clostridium perfringens/crescimento & desenvolvimento , Clostridium perfringens/isolamento & purificação , Plasmídeos/metabolismo , Esporos Bacterianos/genética , Esporos Bacterianos/isolamento & purificação , Esporos Bacterianos/metabolismo
9.
Food Microbiol ; 73: 311-318, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29526218

RESUMO

C. perfringens type A is the causative agent of C. perfringens type A food poisoning (FP) and non-food-borne (NFB) human gastrointestinal diseases. Due to its ability to form highly heat-resistant spores, it is of great interest to develop strategies alternative to thermal processing to inactivate C. perfrinegens. Thus, in this study we evaluated the inhibitory effects of essential oil constituents (EOCs) (cinnamaldehyde, eugenol, allyl isothiocyanate (AITC), and carvacrol) against germination, outgrowth and vegetative growth of spores of C. perfringens FP and NFB disease isolates in laboratory medium and chicken meat. The cinnamaldehyde, eugenol and carvacrol, but not AITC, all at 0.05-0.1%, inhibited the germination of spores of all tested C. perfringens isolates in Tripticase-glucose-yeast extract (TGY) medium. Furthermore, all tested EOCs at 0.05-0.1% arrested the outgrowth and vegetative growth of C. perfringens spores in TGY, with AITC and carvacrol being the most effective. However, among four tested EOCs, only AITC (at 0.5%-2.0%) was able to inhibit the growth of C. perfringens spores in chicken meat and no such inhibitory effect was observed even with a 10-fold higher concentration (5%) of carvacrol. In conclusion, our current work identified AITC as an effective EOC to control spores and vegetative cells of C. perfringens isolates in laboratory medium and chicken meat. Further studies on evaluating the effectiveness of different combination of EOCs against C. perfringens spore growth in different meat products should establish an effective use of EOCs to control the risk of C. perfringens-mediated illnesses.


Assuntos
Clostridium perfringens/efeitos dos fármacos , Carne/microbiologia , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Esporos Bacterianos/crescimento & desenvolvimento , Animais , Galinhas , Clostridium perfringens/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Meios de Cultura/química , Esporos Bacterianos/efeitos dos fármacos
10.
Can J Infect Dis Med Microbiol ; 2018: 6598918, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30675320

RESUMO

Cell phones may be an ideal habitat for colonization by bacterial pathogens, especially in hot climates, and may be a reservoir or vehicle in transmitting nosocomial infections. We investigated bacterial contamination on cell phones of healthcare workers in three hospitals in Saudi Arabia and determined antibacterial resistance of selected bacteria. A questionnaire was submitted to 285 healthcare workers in three hospitals, and information was collected on cell phone usage at the work area and in the toilet, cell phone cleaning and sharing, and awareness of cell phones being a source of infection. Screening on the Vitek 2 Compact system (bioMérieux Inc., USA) was done to characterize bacterial isolates. Of the 60 samples collected from three hospitals, 38 (63.3%) were positive with 38 bacterial isolates (4 Gram-negative and 34 Gram-positive bacteria). We found 38.3% of cell phones were contaminated with coagulase-negative staphylococci, particularly Staphylococcus epidermidis (10 isolates). Other bacterial agents identified were S. aureus, S. hominis, Alloiococcus otitis, Vibrio fluvialis, and Pseudomonas stutzeri. Antimicrobial susceptibility testing showed that most coagulase-negative staphylococci were resistant to benzylpenicillin, erythromycin, and rifampicin. Eight isolates were resistant to oxacillin, specifically S. epidermidis (3), S. hominis (2), and S. warneri (2). A. otitis, a cause of acute otitis media showed multidrug resistance. One isolate, a confirmed hetero-vancomycin intermediate-resistant S. aureus, was resistant to antibiotics, commonly used to treat skin infection. There was a significant correlation between the level of contamination and usage of cell phone at toilet and sharing. Our findings emphasize the importance of hygiene practices in cell phone usage among healthcare workers in preventing the transmission of multidrug-resistant microbes.

11.
Microbiology (Reading) ; 162(11): 1972-1983, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27692042

RESUMO

Clostridium perfringens type A can cause both food poisoning (FP) and non-food-borne (NFB) gastrointestinal diseases. Our previous study reported that a mixture of l-asparagine and KCl (AK)-germinated spores of FP and NFB isolates well, but KCl and, to a lesser extent, l-asparagine induced spore germination only in FP isolates. We now report that the germination response of FP and NFB spores differsignificantly in several defined germinants and rich media. Spores of NFB strain F4969 gerAA, gerKA-KC or gerKC mutants lacking specific germinant receptor proteins germinated more slowly than wild-type spores with rich media, did not germinate with AK and germinated poorly compared to wild-type spores with l-cysteine. The germination defects in the gerKA-KC spores were largely due to loss of GerKC as (i) gerKA spores germinated significantly with all tested germinants, while gerKC spores exhibited poor or no germination; and (ii) germination defects in gerKC spores were largely restored by expressing the wild-type gerKA-KC operon in trans. We also found that gerKA-KC, gerAA and gerKC spores, but not gerKA spores, released dipicolinic acid at a slower rate than wild-type spores with AK. The colony-forming efficiency of F4969 gerKC spores was also ~35-fold lower than that of wild-type spores, while gerAA and wild-type spores had similar viability. Collectively, these results suggest that the GerAA and GerKC proteins play roles in normal germination of C. perfringens NFB isolates and that GerKC, but not GerAA, is important in these spores' apparent viability.


Assuntos
Clostridium perfringens/metabolismo , Esporos Bacterianos/crescimento & desenvolvimento , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Clostridium perfringens/genética , Clostridium perfringens/crescimento & desenvolvimento , Cisteína/metabolismo , Viabilidade Microbiana , Esporos Bacterianos/genética , Esporos Bacterianos/metabolismo
12.
Food Microbiol ; 50: 83-7, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25998819

RESUMO

The protease CspB and the cortex-lytic enzyme SleC are essential for peptoglycan cortex hydrolysis during germination of spores of the Clostridium perfringens food poisoning isolate SM101. In this study, Western blot analyses were used to demonstrate that CspB and SleC are present exclusively in the C. perfringens SM101 spore coat layer fraction and absent in the lysate from decoated spores and from the purified inner spore membrane. These results indicate why decoating treatments greatly reduce both germination and apparent viability of C. perfringens spores in the absence of an exogenous lytic enzyme. In addition, quantitative Western blot analyses showed that there are approximately 2000 and 130,000 molecules of CspB and pro-SleC, respectively, per C. perfringens SM101 spore, consistent with CspB's role in acting catalytically on pro-SleC to convert this zymogen to the active enzyme.


Assuntos
Proteínas de Bactérias/metabolismo , Clostridium perfringens/enzimologia , Esporos Bacterianos/enzimologia , Proteínas de Bactérias/genética , Western Blotting , Clostridium perfringens/genética , Clostridium perfringens/isolamento & purificação , Clostridium perfringens/fisiologia , Hidrólise , Esporos Bacterianos/isolamento & purificação , Esporos Bacterianos/metabolismo
13.
Food Microbiol ; 44: 24-33, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25084641

RESUMO

Clostridium perfringens spore germination plays a critical role in the pathogenesis of C. perfringens-associated food poisoning (FP) and non-food-borne (NFB) gastrointestinal diseases. Germination is initiated when bacterial spores sense specific nutrient germinants (such as amino acids) through germinant receptors (GRs). In this study, we aimed to identify and characterize amino acid germinants for spores of enterotoxigenic C. perfringens type A. The polar, uncharged amino acids at pH 6.0 efficiently induced germination of C. perfringens spores; L-asparagine, L-cysteine, L-serine, and L-threonine triggered germination of spores of most FP and NFB isolates; whereas, L-glutamine was a unique germinant for FP spores. For cysteine- or glutamine-induced germination, gerKC spores (spores of a gerKC mutant derivative of FP strain SM101) germinated to a significantly lower extent and released less DPA than wild type spores; however, a less defective germination phenotype was observed in gerAA or gerKB spores. The germination defects in gerKC spores were partially restored by complementing the gerKC mutant with a recombinant plasmid carrying wild-type gerKA-KC, indicating that GerKC is an essential GR protein. The gerKA, gerKC, and gerKB spores germinated significantly slower with L-serine and L-threonine than their parental strain, suggesting the requirement for these GR proteins for normal germination of C. perfringens spores. In summary, these results indicate that the polar, uncharged amino acids at pH 6.0 are effective germinants for spores of C. perfringens type A and that GerKC is the main GR protein for germination of spores of FP strain SM101 with L-cysteine, L-glutamine, and L-asparagine.


Assuntos
Aminoácidos/metabolismo , Clostridium perfringens/metabolismo , Esporos Bacterianos/crescimento & desenvolvimento , Aminoácidos/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Infecções por Clostridium/microbiologia , Clostridium perfringens/crescimento & desenvolvimento , Humanos , Esporos Bacterianos/metabolismo
14.
J Bacteriol ; 195(22): 5084-91, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24013629

RESUMO

The Gram-positive, anaerobic, spore-forming bacterium Clostridium perfringens causes a variety of diseases in both humans and animals, and spore germination is thought to be the first stage of C. perfringens infection. Previous studies have indicated that the germinant receptor (GR) proteins encoded by the bicistronic gerKA-gerKC operon as well as the proteins encoded by the gerKB and gerAA genes are required for normal germination of C. perfringens spores. We now report the individual role of these GR proteins by analyzing the germination of strains carrying mutations in gerKA, gerKC, or both gerKB and gerAA. Western blot analysis was also used to determine the location and numbers of GerKC proteins in spores. Conclusions from this work include the following: (i) gerKC mutant spores germinate extremely poorly with KCl, l-asparagine, a mixture of asparagine and KCl, or NaPi; (ii) gerKC spores germinate significantly more slowly than wild-type and other GR mutant spores with a 1:1 chelate of Ca(2+) and dipicolinic acid and very slightly more slowly with dodecylamine; (iii) the germination defects in gerKC spores are largely restored by expressing the wild-type gerKA-gerKC operon in trans; (iv) GerKC is required for the spores' viability, almost certainly because of the gerKC spores' poor germination; and (v) GerKC is located in the spores' inner membrane, with ∼250 molecules/spore. Collectively, these results indicate that GerKC is the main GR protein required for nutrient and nonnutrient germination of spores of C. perfringens food-poisoning isolates.


Assuntos
Proteínas de Bactérias/análise , Membrana Celular/química , Clostridium perfringens/química , Clostridium perfringens/crescimento & desenvolvimento , Esporos Bacterianos/química , Esporos Bacterianos/crescimento & desenvolvimento , Proteínas de Bactérias/genética , Western Blotting , Técnicas de Inativação de Genes
15.
Microorganisms ; 11(3)2023 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-36985165

RESUMO

Spore germination plays an essential role in the pathogenesis of Clostridium perfringens-associated food poisoning. Germination is initiated when bacterial spores sense various stimuli, including chemicals and enzymes. A previous study showed that dipicolinic acid (DPA) chelated with calcium (Ca-DPA) significantly stimulated spore germination in C. perfringens. However, whether Ca2+ or DPA alone can induce germination is unknown. Therefore, we aimed to evaluate the possible roles of Ca2+ and other divalent cations present in the spore core, such as Mn2+ and Mg2+, in C. perfringens spore germination. Our study demonstrated that (i) Ca-DPA, but not DPA alone, induced C. perfringens spore germination, suggesting that Ca2+ might play a signaling role; (ii) all tested calcium salts induced spore germination, indicating that Ca2+ is critical for germination; (iii) the spore-specific divalent cations Mn2+ and Mg2+, but not Zn2+, induced spore germination, suggesting that spore core-specific divalent cations are involved in C. perfringens spore germination; and (iv) endogenous Ca2+ and Mg2+ are not required for induction of C. perfringens spore germination, whereas exogenous and partly endogenous Mn2+ are required. Collectively, our results suggest that exogenous spore core-specific divalent cation signals are more important than endogenous signals for the induction of spore germination.

16.
Pathogens ; 12(9)2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37764883

RESUMO

Bloodstream infection (BSI) prevalence in hospitalized patients has increased owing to the spread of antibiotic-resistant pathogens; moreover, antimicrobial resistance in bacteria is a global problem. Here, BSIs are investigated in several patients at a hospital in Saudi Arabia, and the resistance of bacterial isolates to widely used drugs is determined. Throughout 2020, bacteria isolated from patients were identified and subjected to antibiotic susceptibility testing. In total, 1125 bacterial isolates were obtained from 1039 patients; among them, gram-positive bacteria were significantly more abundant than gram-negative bacteria. The most prevalent bacteria were Staphylococcus epidermidis and Klebsiella pneumoniae. Notably, gram-negative bacteria were mainly isolated from adult patients, and 20.63% of the gram-positive isolates were from pediatric patients, which was significantly higher than the corresponding percentages in elders and adults. The gram-positive isolates were mainly resistant to cephalothin, oxacillin, amoxicillin-clavulanate, and erythromycin and susceptible to penicillin, gentamicin, ciprofloxacin, and vancomycin. Additionally, the gram-negative isolates were mainly resistant to ampicillin, cephalothin, and amoxicillin-clavulanate and susceptible to amikacin, ertapenem, aztreonam, colistin, and trimethoprim-sulfamethoxazole. Consequently, the high prevalence of infective multidrug-resistant bacteria may account as a significant health issue; it is considered a hazard in Riyadh hospitals and must be prevented at all costs.

17.
Biology (Basel) ; 12(5)2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37237475

RESUMO

Nanotechnology based on nanoscale materials is rapidly being used in clinical settings, particularly as a new approach for infectious illnesses. Recently, many physical/chemical approaches utilized to produce nanoparticles are expensive and highly unsafe to biological species and ecosystems. This study demonstrated an environmentally friendly mode of producing nanoparticles (NPs) where Fusarium oxysporum has been employed for generation of silver nanoparticles (AgNPs), which were further tested for their antimicrobial potentials against a variety of pathogenic microorganisms. The characterization of NPs was completed by UV-Vis spectroscopy, DLS and TEM, where it has been found that the NPs were mostly globular, with the size range of 50 to 100 nm. The myco-synthesized AgNPs showed prominent antibacterial potency observed as zone of inhibition of 2.6 mm, 1.8 mm, 1.5 mm, and 1.8 mm against Vibrio cholerae, Streptococcus pneumoniae, Klebsiella pneumoniae and Bacillus anthracis, respectively, at 100 µM. Similarly, at 200 µM for A. alternata, A. flavus and Trichoderma have shown zone of inhibition as 2.6 mm, 2.4 mm, and 2.1 mm, respectively. Moreover, SEM analysis of A. alternata confirmed the hyphal damage where the layers of membranes were torn off, and further EDX data analysis showed the presence of silver NPs, which might be responsible for hyphal damage. The potency of NPs may be related with the capping of fungal proteins that are produced extracellularly. Thus, these AgNPs may be used against pathogenic microbes and play a beneficial role against multi-drug resistance.

18.
Vaccines (Basel) ; 11(2)2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36851085

RESUMO

The objective of this study is to assess the frequency and severity of adverse events following immunization (AEFI) in Indian children aged 5-17 years who received the Pfizer-BioNTech mRNA COVID-19 vaccine, as well as to investigate for predictors of AEFI. To examine AEFI following the first and second doses of Pfizer's vaccine, semi-structured questionnaires were distributed as Google forms at Indian schools in Saudi Arabia. The 385 responses included 48.1% male and 51.9% female children, with 136 responses of children aged 5-11 years (group A) and 249 responses from children aged 12-17 years (group B). Overall, 84.4% of children had two shots. The frequency of AEFI was reported to be higher after the first dose than after the second (OR = 2.12, 95% CI = 1.57-2.86). The reported AEFIs included myalgia, rhinitis, local reaction with fever, a temperature of 102 °F or higher, and mild to moderate injection site reactions. While group B frequently reported multiple AEFIs, group A typically reported just one. Local reaction with low grade fever was more frequently reported in group B after the first dose (24.1%) and second dose (15.4%), while local reaction without low grade fever was most frequently observed in group A after the first (36.8%) and second dose (30%). Only prior COVID-19 infection (OR = 2.98, 95% CI = 1.44-6.2) was associated with AEFI after the second dose in the study sample, whereas male gender (OR = 1.71, 95% CI = 1.13-2.6) and prior COVID-19 infection (OR = 2.95, 95% CI = 1.38-6.3) were predictors of AEFI after the first dose. Non-serious myocarditis was reported by only one child. According to the analysis conducted, the Pfizer's mRNA COVID-19 vaccination was found to be safe in Indian children.

19.
Front Nutr ; 10: 1185236, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37324729

RESUMO

To valorise the bioactive constituents abundant in leaves and other parts of medicinal plants with the objective to minimize the plant-based wastes, this study was undertaken. The main bioactive constituent of Andrographis paniculata, an Asian medicinal plant, is andrographolide (AG, a diterpenoid), which has shown promising results in the treatment of neurodegenerative illnesses. Continuous electrical activity in the brain is a hallmark of the abnormal neurological conditions such as epilepsy (EY). This can lead to neurological sequelae. In this study, we used GSE28674 as a microarray expression profiling dataset to identify DEGs associated with andrographolide and those with fold changes >1 and p-value <0.05 GEO2R. We obtained eight DEG datasets (two up and six down). There was marked enrichment under various Kyoto Encyclopaedia of Genes and Genomes (KEGG) and Gene Ontology (GO) terms for these DEGs (DUSP10, FN1, AR, PRKCE, CA12, RBP4, GABRG2, and GABRA2). Synaptic vesicles and plasma membranes were the predominant sites of DEG expression. AG acts as an antiepileptic agent by upregulating GABA levels. The low bioavailability of AG is a significant limitation of its application. To control these limitations, andrographolide nanoparticles (AGNPs) were prepared and their neuroprotective effect against pentylenetetrazol (PTZ)-induced kindling epilepsy was investigated using network pharmacology (NP) and docking studies to evaluate the antiepileptic multi-target mechanisms of AG. Andrographolide is associated with eight targets in the treatment of epilepsy. Nicotine addiction, GABAergic synapse, and morphine addiction were mainly related to epilepsy, according to KEGG pathway enrichment analysis (p < 0.05). A docking study showed that andrographolide interacted with the key targets. AG regulates epilepsy and exerts its therapeutic effects by stimulating GABA production. Rats received 80 mg/kg body weight of AG and AGNP, phenytoin and PTZ (30 mg/kg i.p. injection on alternate days), brain MDA, SOD, GSH, GABAand histological changes of hippocampus and cortex were observed. PTZ injected rats showed significantly (***p < 0.001) increased kindling behavior, increased MDA, decreased GSH, SOD, GABA activities, compared with normal rats, while treatment AGNPs significantly reduced kindling score and reversed oxidative damage. Finally, we conclude that the leaves and roots of A. Paniculata can be effectively utilized for its major bioactive constituent, andrographolide as a potent anti-epileptic agent. Furthermore, the findings of novel nanotherapeutic approach claim that nano-andrographolide can be successfully in the management of kindling seizures and neurodegenerative disorders.

20.
Antibiotics (Basel) ; 11(9)2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36139945

RESUMO

Clostridium is a genus comprising Gram-positive, rod-shaped, spore-forming, anaerobic bacteria that cause a variety of diseases. However, there is a shortage of information regarding antibiotic resistance in the genus in Saudi Arabia. This comprehensive analysis of research results published up until December 2021 intends to highlight the incidence of antibiotic resistance in Clostridium species in Saudi Arabia. PubMed, Google Scholar, Web of Science, SDL, and ScienceDirect databases were searched using specific keywords, and ten publications on antibiotic resistance in Clostridium species in Saudi Arabia were identified. We found that the rates of resistance of Clostridium difficile to antibiotics were as follows: 42% for ciprofloxacin, 83% for gentamicin, 28% for clindamycin, 25% for penicillin, 100% for levofloxacin, 24% for tetracycline, 77% for nalidixic acid, 50% for erythromycin, 72% for ampicillin, and 28% for moxifloxacin; whereas those of C. perfringens were: 21% for metronidazole, 83% for ceftiofur, 39% for clindamycin, 59% for penicillin, 62% for erythromycin, 47% for oxytetracycline, and 47% for lincomycin. The current findings suggest that ceftiofur, erythromycin, lincomycin, and oxytetracycline should not be used in C. perfringens infection treatments in humans or animals in Saudi Arabia.

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