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1.
Curr Microbiol ; 79(2): 62, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-34994875

RESUMO

Fusariosis affects cereal grain crops worldwide and is responsible for devastating crops, reducing grain quality and yield, and producing strong mycotoxins. Benzimidazoles and triazoles were recommended to combat fusariosis; however, there were reports of resistance, making it necessary to reflect on the reasons for this occurrence. The purpose of this review was to evaluate the fusariosis resistance to the main agricultural fungicides, to observe whether this resistance can cause changes in the production of mycotoxins, and to verify the influence of resistance on the cereal grain production chain. Scientific articles were selected from the ScienceDirect, Scopus, and Pubmed databases, published at maximum 10 years ago and covering the main fungicide classes that combat phytopathogenesis and mycotoxin production. A high occurrence of resistance to carbendazim was found, while few reports of resistance to triazoles are available. The effectiveness of strobilurins is doubtful, due to an increase of mycotoxins linked to it. It is possible to conclude that the large-scale use of fungicides can select resistant strains that will contribute to an increase in the production of mycotoxins and harm sectors of the world economy, not only the agriculture, but also sanitation and foreign trade.


Assuntos
Fungicidas Industriais , Fusarium , Micotoxinas , Grão Comestível , Fungicidas Industriais/farmacologia , Doenças das Plantas
2.
BMC Genomics ; 23(1): 20, 2022 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-34996351

RESUMO

BACKGROUND: Carbapenem-resistant hypervirulent K. pneumoniae (CR-hvKP) causes serious infections with significant morbidity and mortality. However, the epidemiology and transmission mechanisms of CR-hvKP and the corresponding carbapenem-resistant plasmids require further investigation. Herein, we have characterized an ST11 K. pneumoniae strain EBSI041 from the blood sample encoding both hypervirulence and carbapenem resistance phenotypes from a patient in Egypt. RESULTS: K. pneumoniae strain EBSI041 showed multidrug-resistance phenotypes, where it was highly resistant to almost all tested antibiotics including carbapenems. And hypervirulence phenotypes of EBSI041 was confirmed by the model of Galleria mellonella infection. Whole-genome sequencing analysis showed that the hybrid plasmid pEBSI041-1 carried a set of virulence factors rmpA, rmpA2, iucABCD and iutA, and six resistance genes aph(3')-VI, armA, msr(E), mph(E), qnrS, and sul2. Besides, blaOXA-48 and blaSHV-12 were harboured in a novel conjugative IncL-type plasmid pEBSI041-2. The blaKPC-2-carrying plasmid pEBSI041-3, a non-conjugative plasmid lacking the conjugative transfer genes, could be transferred with the help of pEBSI041-2, and the two plasmids could fuse into a new plasmid during co-transfer. Moreover, the emergence of the p16HN-263_KPC-like plasmids is likely due to the integration of pEBSI041-3 and pEBSI041-4 via IS26-mediated rearrangement. CONCLUSION: To the best of our knowledge, this is the first report on the complete genome sequence of KPC-2- and OXA-48-coproducing hypervirulent K. pneumoniae from Egypt. These results give new insights into the adaptation and evolution of K. pneumoniae during nosocomial infections.


Assuntos
Infecções por Klebsiella , Klebsiella pneumoniae , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Carbapenêmicos/farmacologia , Egito , Humanos , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , Plasmídeos/genética , beta-Lactamases/genética
3.
Int J Nanomedicine ; 17: 45-60, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35027826

RESUMO

Introduction: Modulating the inflammatory response of human gingival fibroblasts (hGFs) is important for the control of periodontal inflammation because it is a key event in the pathogenesis of periodontitis. Here, we aimed to determine whether polyglucose sorbitol carboxymethyl ether (PSC)-coated superparamagnetic iron oxide nanoparticles (SPIONs) protect hGFs against invasion and inflammatory stimulation by Porphyromonas gingivalis (P. gingivalis). Methods: First, we determined the cytotoxicity and antimicrobial activity of PSC-SPIONs. Then, their effects on invasion of hGFs by P. gingivalis were evaluated by counting invading P. gingivalis, fluorescence staining, and transmission electron microscopy. The effect of PSC-SPIONs on inflammation in hGFs induced by P. gingivalis lipopolysaccharide was evaluated by measurement of reactive oxygen species (ROS), and enzyme-linked immunosorbent assays, quantitative reverse transcription-polymerase chain reaction, and Western blotting of key indicator molecules. The effects of dimercaptosuccinic acid (DMSA)-coated SPIONs and the free form of PSC alone were also tested and compared with those of PSC-SPIONs. Results: PSC-SPIONs (25 µg/mL) are cytocompatible with hGFs and exhibit no antimicrobial effects on P. gingivalis. However, they inhibit invasion of hGFs by P. gingivalis at 15 µg/mL. They also decrease ROS production and inflammatory cytokine secretion by hGFs at 5, 15, and 25 µg/mL, by downregulating activation of the nuclear factor-kappa B signaling pathway. Furthermore, PSC alone does not inhibit inflammation, while DMSA-SPIONs do. This indicates that the nanosize effects of PSC-SPIONs, rather than their coating material, play the dominant role in their anti-inflammatory activity. Conclusion: PSC-SPIONs protect hGFs against P. gingivalis invasion and inflammatory stimulation. Thus, they have potential for clinical application in control of periodontal inflammation.


Assuntos
Gengiva , Porphyromonas gingivalis , Células Cultivadas , Fibroblastos , Humanos , Lipopolissacarídeos/farmacologia
4.
Int J Nanomedicine ; 17: 91-104, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35027828

RESUMO

Purpose: Traumatic spinal cord injury (TSCI) induces a powerful inflammatory response that can significantly exacerbate the extent and severity of neural damage (termed as "secondary injury"). Thus, the suppression of inflammation is crucial for reducing neurological dysfunction following TSCI. However, the conventional anti-inflammatory drugs show limited efficacy because of poor penetration and release kinetics at the injury site. This study describes the design, synthesis, release kinetics, biosafety, and preclinical efficacy of minocycline (MC)-loaded poly(α-lipoic acid)-methylprednisolone (PαLA-MP) prodrug nanoparticles (NPs) for the combined anti-inflammatory treatment of TSCI. Methods: NPs were produced by conjugating MP to PαLA and then loading MC. The NP structure was confirmed through 1H nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy, ultraviolet-visible absorption spectroscopy, gel permeation chromatography, dynamic light scattering, and transmission electron microscopy. Drug-loading content and efficacy were measured using high-performance liquid chromatography (HPLC) or 1H NMR and release kinetics through HPLC. Biosafety was examined using the MTT assay, cell penetration efficiency using confocal microscopy, and flow cytometry using Cyanine5 (Cy5)-labeled MC-PαLA-MP NPs, effects on injury-induced pro-inflammatory cytokine release using enzyme-linked immunosorbent assays and immunofluorescence, and treatment efficacy by measuring motor recovery in a rat model of TSCI. Results: The MC-PαLA-MP NPs exhibited high biocompatibility and released 81% MC and 54% MP within 24 h under TSCI-like conditions, effectively reducing 40% of pro-inflammatory cytokine release both in cultures and injured rat spinal cord tissues. Systemic injection increased the Basso, Beattie, Bresnahan score of TSCI rats from 2.33 ± 0.52 to 8.83 ± 1.83 in 8 weeks, providing effective neuroprotection and enhanced exercise recovery in the TSCI rats. Conclusion: The MC-PαLA-MP NPs can mitigate secondary inflammation and preserve motor function following experimental TSCI, which suggests their potential for clinical application.


Assuntos
Nanopartículas , Pró-Fármacos , Traumatismos da Medula Espinal , Ácido Tióctico , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Metilprednisolona , Minociclina , Pró-Fármacos/uso terapêutico , Ratos , Recuperação de Função Fisiológica , Medula Espinal , Traumatismos da Medula Espinal/tratamento farmacológico
5.
Prog Chem Org Nat Prod ; 117: 1-106, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34977998

RESUMO

Natural products have made a crucial and unique contribution to human health, and this is especially true in the case of malaria, where the natural products quinine and artemisinin and their derivatives and analogues, have saved millions of lives. The need for new drugs to treat malaria is still urgent, since the most dangerous malaria parasite, Plasmodium falciparum, has become resistant to quinine and most of its derivatives and is becoming resistant to artemisinin and its derivatives. This volume begins with a short history of malaria and follows this with a summary of its biology. It then traces the fascinating history of the discovery of quinine for malaria treatment and then describes quinine's biosynthesis, its mechanism of action, and its clinical use, concluding with a discussion of synthetic antimalarial agents based on quinine's structure. The volume then covers the discovery of artemisinin and its development as the source of the most effective current antimalarial drug, including summaries of its synthesis and biosynthesis, its mechanism of action, and its clinical use and resistance. A short discussion of other clinically used antimalarial natural products leads to a detailed treatment of other natural products with significant antiplasmodial activity, classified by compound type. Although the search for new antimalarial natural products from Nature's combinatorial library is challenging, it is very likely to yield new antimalarial drugs. The chapter thus ends by identifying over ten natural products with development potential as clinical antimalarial agents.


Assuntos
Antimaláricos , Produtos Biológicos , Malária , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Produtos Biológicos/farmacologia , Humanos , Malária/tratamento farmacológico , Plasmodium falciparum , Quinina/farmacologia , Quinina/uso terapêutico
6.
Gen Dent ; 70(1): 40-44, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34978989

RESUMO

This study sought to compare a bioceramic sealer (TotalFill) and a calcium hydroxide (Ca[OH]2) sealer (Sealapex) in terms of their pH, calcium ion (Ca²âº) release, and antibacterial effect against Enterococcus faecalis bacteria. For the pH and Ca²âº release tests, 20 polyethylene tubes (10 mm in height and 1 mm in internal diameter) were filled with the appropriate sealer (n = 10 per sealer), immersed in glass flasks each containing 10 mL of deionized water, and stored in an incubator at 37°C. The water was changed after 1, 7, 28, and 90 days. At each water change, the eluates were measured with an advanced electrochemistry meter to determine the pH and with a flame atomic absorption spectrometer to determine the Ca²âº release. The antibacterial effect was measured using the turbidimetry-based direct contact test in which the wells of a microtiter plate were coated with a thin, even layer of freshly prepared sealer (10 wells per sealer), which was allowed to set before application of a suspension of E faecalis. Control wells were obtained by placing an identical bacterial suspension in 10 uncoated wells. The optical density of the sealer and control groups was measured immediately and 1, 3, and 7 days after sealer preparation. Data were analyzed for normality with the Shapiro-Wilk and Kolmogorov-Smirnov tests. Two-way analysis of variance (ANOVA), Student t test, and 1-way ANOVA with Tukey post hoc tests were all utilized with a significance level of P < 0.05. TotalFill maintained significantly higher pH and Ca²âº release levels than Sealapex at all evaluation times (P < 0.05). Both sealers demonstrated significantly greater antibacterial effect (lower optical density) than the control group; however, TotalFill resulted in significantly lower optical density values than Sealapex (P < 0.05). TotalFill bioceramic sealer demonstrated superior Ca(OH)2-related properties compared to Sealapex Ca(OH)2 sealer.


Assuntos
Cálcio , Materiais Restauradores do Canal Radicular , Antibacterianos/farmacologia , Resinas Epóxi , Humanos , Concentração de Íons de Hidrogênio , Teste de Materiais , Materiais Restauradores do Canal Radicular/farmacologia , Silicatos
7.
J Eur Acad Dermatol Venereol ; 36 Suppl 2: 16-25, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34979591

RESUMO

Probiotics are live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host. Semiactive, non-replicating bacteria or extracts used in dermocosmetics have interesting properties for skin quality. Vitreoscilla filiformis is cultured by a fermentation process to obtain an extract. It is considered as a probiotic fraction and topical application of this extract has shown activity to strengthen the skin physical barrier function and maintain good homeostasis of skin defenses. Vichy volcanic mineralizing water (VVMW) is a pure, highly mineralized water that has been shown to strengthen the skin against exposome aggressions. This manuscript reviews properties of probiotic fractions used in skin care, especially studies on an extract of V. filiformis grown in a medium containing VVMW (VfeV) and evaluated in combination with VVMW. Skin barrier function: In normal human epidermal keratinocyte cultures, the combination of 10% VVMW and 0.002% VfeV significantly increased transglutaminase, filaggrin, involucrin, claudin-1, and zonula occludens-1 in comparison with the controls. Antimicrobial peptide defenses: The combination of 16.7% VVMW and 0.1% VfeV increased the expression of ß-defensin-4A and S100A7. Skin immune defense functions: In lipopolysaccharide-stimulated peripheral blood mononuclear cells, the combination of 16.7% VVMW and 0.1% VfeV down-regulated IL-8, TNF-α, IL-12/IL-23p40, and increased IL10 and IL-10/IL-12 ratio compared to the control. Additionally, the combination of 79% VVMW plus 5% VfeV protected Langerhans cells in skin explants exposed to ultraviolet radiation. In conclusion, the combination of VfeV plus VVMW has properties to strengthen the skin barrier by stimulating skin differentiation and tight junctions, biochemical defenses by stimulating antimicrobial peptides, and cellular immune defenses by increasing the IL-10/IL-12 ratio and by protecting Langerhans cells challenged by ultraviolet radiation.


Assuntos
Água , Humanos , Queratinócitos , Leucócitos Mononucleares , Extratos Vegetais/farmacologia , Raios Ultravioleta , Vitreoscilla
8.
BMC Complement Med Ther ; 22(1): 7, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34983472

RESUMO

BACKGROUND: Patrinia scabra Bunge is a well-known herbal medicine for its favorable treatment on inflammatory diseases owing to its effective ingredients, in which iridoid glycoside plays an extremely significant role. This article aimed to improve the content of total iridoid glycosides in crude extract through a series optimization of extraction procedure. Moreover, considering that both pain and inflammation are two correlated responses triggered in response to injury, irritants or pathogen, the article investigated the anti-inflammatory and analgesic activities of P. scabra to screen out the active fraction. METHOD: P. scabra was extracted by ultrasonic-microwave synergistic extraction (UMSE) to obtain total iridoid glycosides (PSI), during which a series of conditions were investigated based on single-factor experiments. The extraction process was further optimized by a reliable statistical method of response surface methodology (RSM). The elution fractions of P. scabra extract were prepared by macroporous resin column chromatography. Through the various animal experiment including acetic acid-induced writhing test, formalin induced licking and flinching, carrageenan-induced mice paw oedema test and xylene-induced ear edema in mice, the active fractions with favorable analgesic and anti-inflammatory effect were reasonably screen out. RESULTS: The content of PSI could reach up to 81.42 ± 0.31 mg/g under the optimum conditions as follows: ethanol concentration of 52%, material-to-liquid ratio of 1:18 g/mL, microwave power at 610 W and extraction time of 45 min. After gradient elution by the macroporous resin, the content of PSI increased significantly. Compared with other concentrations of elution liquid, the content of PSI in 30 and 50% ethanol eluate was increased to reach 497.65 and 506.90 mg/g, respectively. Owing to the pharmacology experiment, it was reasonably revealed that 30 and 50% ethanol elution fractions of P. scabra could relieve pain centrally and peripherally, exhibiting good analgesic and anti-inflammatory activities. CONCLUSION: Patrinia scabra possessed rich iridoids and exhibited significant analgesic and anti-inflammatory activities.


Assuntos
Anti-Inflamatórios/farmacocinética , Glicosídeos Iridoides/farmacologia , Iridoides/farmacologia , Micro-Ondas , Patrinia/metabolismo , Ultrassom , Analgésicos/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Inflamação/tratamento farmacológico , Iridoides/uso terapêutico , Camundongos , Dor/tratamento farmacológico , Fitoterapia , Plantas Medicinais/metabolismo
9.
BMC Complement Med Ther ; 22(1): 6, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34983480

RESUMO

BACKGROUND: Quercus acuta Thunb. (Fagaceae) or Japanese evergreen oak is cultivated as an ornamental plant in South Korea, China, Japan, and Taiwan and used in traditional medicine. The acorn or fruit of Quercus acuta Thunb. (QAF) is the main ingredient of acorn jelly, a traditional food in Korea. Its leaf was recently shown to have potent xanthine oxidase inhibitory and anti-hyperuricemic activities; however, there have been no studies on the biological activity of QAF extracts. Solar ultraviolet light triggers photoaging of the skin, which increases the production of reactive oxygen species (ROS) and expression of matrix metalloproteinase (MMPs), and destroys collagen fibers, consequently inducing wrinkle formation. The aim of this study was to investigate the effect of water extracts of QAF against UVB-induced skin photoaging and to elucidate the underlying molecular mechanisms in human keratinocytes (HaCaT). METHODS: In this study, we used HPLC to identify the major active components of QAF water extracts. Anti-photoaging effects of QAF extracts were evaluated by analyzing ROS procollagen type I in UVB-irradiated HaCaT keratinocytes. Antiradical activity was determined using 2,2-diphenyl-1-picrylhydrazyl and 2,20-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) assays. The expression of MMP-1 was tested by western blotting and ELISA kits. QAF effects on phosphorylation of the MAPK (p38, JNK, and ERK) pathway and transcription factor AP-1, which enhances the expression of MMPs, were analyzed by western blots. RESULTS: We identified two major active components in QAF water extracts, gallotannic acid and ellagic acid. The QAF aqueous extracts recovered UVB-induced cell toxicity and reduced oxidative stress by inhibiting intracellular ROS generation in HaCaT cells. QAF rescued UVB-induced collagen degradation by suppressing MMP-1 expression. The anti-photoaging activities of QAF were associated with the inhibition of UVB-induced phosphorylation of extracellular signal-regulated kinase (ERK) and activator protein 1 (AP-1). Our findings indicated that QAF prevents UVB-induced skin damage due to collagen degradation and MMP-1 activation via inactivation of the ERK/AP-1 signaling pathway. Overall, this study strongly suggests that QAF exerts anti-skin-aging effects and is a potential natural biomaterial that inhibits UVB-induced photoaging. CONCLUSION: These results show that QAF water extract effectively prevents skin photoaging by enhancing collagen deposition and inhibiting MMP-1 via the ERK/AP-1 signaling pathway.


Assuntos
MAP Quinases Reguladas por Sinal Extracelular/farmacologia , Queratinócitos/efeitos dos fármacos , Quercus/metabolismo , Transdução de Sinais , Envelhecimento da Pele/efeitos dos fármacos , Fator de Transcrição AP-1/farmacologia , Raios Ultravioleta/efeitos adversos , Humanos , Extratos Vegetais/farmacologia
10.
BMC Complement Med Ther ; 22(1): 4, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34983490

RESUMO

BACKGROUND: Though Lippia javanica (Burm.f.) Spreng antioxidant activity has been demonstrated, its effect in protecting the brain from lead (Pb)-induced oxidative damage is unknown. This study investigated the effect of L. javanica against Pb-induced oxidative stress, inflammation, apoptosis and acetylcholinesterase activity in rat's brain. METHODS: L. javanica herbal tea infusion was prepared, its phytochemical constituent was revealed by liquid chromatography-Mass spectrometer (LC-MS) and was administered simultaneously with Pb. Four groups of male Wistar rats (n = 5/group) were used: control received distilled water; Pb-acetate group received 50 mg Pb/ Kg bodyweight (bw), treatment group received 50 mg Pb/ Kg Pb-acetate + 5 ml/kg bw L. javanica and L. javanica group received 5 ml/Kg bw of L. javanica tea infusion only. After 6 weeks of treatment, oxidative status, acetylcholinesterase activity, inflammation and apoptosis was assessed in brain tissue which was also histologically examined. RESULTS: Mean brain and heart weight was reduced (p < 0.05) while liver and spleen weights were increased (p < 0.05) in Pb exposed animals but were prevented by L. juvanica treatment. Treatment with L. javanica increased (p < 0.05) overall brain antioxidant status (glutathione and superoxide dismutase activities) and reduced lipid peroxidation (p < 0.05) compared to the Pb exposed animals. Pro-inflammatory cytokine tumour necrotic factor-alpha, pro-apoptosis Bax protein and anticholinesterase activity were reduced (p < 0.05) in Pb-L. javanica treated animals compared to the Pb exposed group. Histological examination confirmed neuroprotective effects of L. javanica as evidenced by reduced apoptosis/necrosis and inflammation-induced vacuolization and oedema in the hippocampus. The L. javanica treatment alone had no detrimental effects to the rats. LC-MS analysis revealed L. javanica to be rich in phenolics. CONCLUSIONS: This study demonstrated that L. javanica, rich in phenolics was effective in reducing Pb-induced brain oxidative stress, inflammation, apoptosis, acetylcholinesterase activity and neuronal damage.


Assuntos
Encéfalo/metabolismo , Chumbo/efeitos adversos , Lippia/metabolismo , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Chás de Ervas , Animais , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar
11.
Theranostics ; 12(1): 1-17, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34987630

RESUMO

Background: Administration of potent anti-receptor-binding domain (RBD) monoclonal antibodies has been shown to curtail viral shedding and reduce hospitalization in patients with SARS-CoV-2 infection. However, the structure-function analysis of potent human anti-RBD monoclonal antibodies and its links to the formulation of antibody cocktails remains largely elusive. Methods: Previously, we isolated a panel of neutralizing anti-RBD monoclonal antibodies from convalescent patients and showed their neutralization efficacy in vitro. Here, we elucidate the mechanism of action of antibodies and dissect antibodies at the epitope level, which leads to a formation of a potent antibody cocktail. Results: We found that representative antibodies which target non-overlapping epitopes are effective against wild type virus and recently emerging variants of concern, whilst being encoded by antibody genes with few somatic mutations. Neutralization is associated with the inhibition of binding of viral RBD to ACE2 and possibly of the subsequent fusion process. Structural analysis of representative antibodies, by cryo-electron microscopy and crystallography, reveals that they have some unique aspects that are of potential value while sharing some features in common with previously reported neutralizing monoclonal antibodies. For instance, one has a common VH 3-53 public variable region yet is unusually resilient to mutation at residue 501 of the RBD. We evaluate the in vivo efficacy of an antibody cocktail consisting of two potent non-competing anti-RBD antibodies in a Syrian hamster model. We demonstrate that the cocktail prevents weight loss, reduces lung viral load and attenuates pulmonary inflammation in hamsters in both prophylactic and therapeutic settings. Although neutralization of one of these antibodies is abrogated by the mutations of variant B.1.351, it is also possible to produce a bi-valent cocktail of antibodies both of which are resilient to variants B.1.1.7, B.1.351 and B.1.617.2. Conclusions: These findings support the up-to-date and rational design of an anti-RBD antibody cocktail as a therapeutic candidate against COVID-19.


Assuntos
Anticorpos Monoclonais/química , Anticorpos Monoclonais/farmacologia , COVID-19/tratamento farmacológico , SARS-CoV-2/metabolismo , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , Anticorpos Monoclonais/metabolismo , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/farmacologia , Sítios de Ligação , Ligação Competitiva , COVID-19/virologia , Cricetinae , Microscopia Crioeletrônica , Cristalografia por Raios X , Cães , Epitopos , Feminino , Humanos , Células Madin Darby de Rim Canino , Testes de Neutralização , Domínios Proteicos , SARS-CoV-2/genética , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidade , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo
12.
Arch Microbiol ; 204(2): 124, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-34997335

RESUMO

Soil pH conditions have important consequences for microbial community structure, their dynamics, ecosystem processes, and interactions with plants. Low soil pH affects the growth and functional activity of bacterial biocontrol agents which may experience a paradigm shift in their ability to act antagonistically against fungal phytopathogens. In this study, the antifungal activity of an acid-tolerant soil bacterium Bacillus amyloliquefaciens MBNC was evaluated under low pH and compared to its activity in neutral pH conditions. Bacterial supernatant from 3-day-old culture (approximately 11.2 × 108 cells/mL) grown in low pH conditions was found more effective against fungal pathogens. B. amyloliquefaciens MBNC harboured genes involved in the synthesis of secondary metabolites of which surfactin homologues, with varying chain length (C11-C15), were identified through High-Resolution Mass Spectroscopy. The pH of the medium influenced the production of these metabolites. Surfactin C15 was exclusive to the extract of pH 4.5; production of iturinA and surfactin C11 was detected only in pH 7.0, while surfactin C12, C13 and C14 were detected in extracts of both the pH conditions. The secretion of phytohormones viz. indole acetic acid and gibberellic acid by B. amyloliquefaciens MBNC was detected in higher amounts in neutral condition compared to acidic condition. Although, secretion of metabolites and phytohormones in B. amyloliquefaciens MBNC was influenced by the pH condition of the medium, the isolate retained its antagonistic efficiency against several fungal phyto-pathogens under acidic condition.


Assuntos
Bacillus amyloliquefaciens , Antifúngicos/farmacologia , Ecossistema , Fungos , Concentração de Íons de Hidrogênio , Lipopeptídeos , Doenças das Plantas
13.
Arch Microbiol ; 204(2): 126, 2022 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-34997845

RESUMO

The mechanism of berberine hydrochloride (BBH) inhibiting the biofilm formation of Hafnia alvei was investigated in this study. The antibiofilm potential of BBH was evaluated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) as well as crystal violet staining. The quorum-sensing (QS) inhibition was revealed by determination of QS-related genes expression and related signal molecules production using real-time quantitative PCR (RT-qPCR) and high performance liquid chromatography (HPLC). The binding of BBH to receptor proteins was simulated by molecular docking and molecular dynamics simulations. It was found that BBH at sub-minimum inhibitory concentrations (sub-MICs) significantly reduced the biofilm formation of H. alvei in a dose dependent manner. BBH inhibited the bacterial swimming motility, decreased the transcription of halI and halR genes, and reduced the production of signal molecule C14-HSL. It bound to HalR protein mainly through Van der Waals force and electrostatic interaction force. Based on these results, it was concluded that BBH inhibits the biofilm formation of H. alvei and the mechanism is related to its interference with QS through down-regulating the expression of halI and halR genes.


Assuntos
Berberina , Hafnia alvei , Antibacterianos/farmacologia , Berberina/farmacologia , Biofilmes , Simulação de Acoplamento Molecular , Percepção de Quorum
14.
Mymensingh Med J ; 31(1): 31-36, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34999676

RESUMO

Plasmid mediated quinolone resistance (PMQR) has been revealed to play not only a significant role in quinolone resistance but also this drug resistance can spread from one bacterium to another. There is limited data regarding the prevalence of PMQR are available from Bangladesh. So, the aim of this study was to detect the prevalence of qnr and aac(6')-Ib-cr genes among clinical isolates of ciprofloxacin resistant Proteus spp. This cross-sectional study was carried out in the Department of Microbiology of Dhaka Medical College, Dhaka, Bangladesh from July 2018 to June 2019. Fourty (40) Proteus spp. was isolated from 300 culture positive samples. Proteus mirabilis and Proteus vulgaris were identified by culture and biochemical test. Antibiotic susceptibility was performed by disc-diffusion technique. Quinolone resistance genes (qnrA, qnrB, qnrC, qnrD, qnrS and aac(6')-1b-cr) among ciprofloxacin resistant Proteus spp. were detected by PCR. Thirty (75%) ciprofloxacin resistant isolates were detected during disk-diffusion technique. Among them, quinolone resistance genes were found positive 11(36.67%) for aac(6')-Ib-cr, 6(20%) for qnrA, 5(16.67%) for qnrD, 4(13.33%) for qnrS and 3(10%) for qnrB genes. Co-existance of qnrA + aac(6')-Ib-cr and qnrD + qnrS were found in 3(10%) wound swab & pus and urine samples respectively followed by qnrA + qnrB in 2(6.67%) wound swab and pus and qnrA+qnrS in 1(3.33%) urine sample. The results of this study showed presence of high (66.67%) percentage of PMQR genes as well as high (30%) rate of co-carriage of the two genes among Proteus spp. isolates. The incidence of PMQR genes was found to be high which could be due to the increased prescription of fluoroquinolones. Thus, there is a need for rational usage of fluoroquinolones.


Assuntos
Farmacorresistência Bacteriana , Proteínas de Escherichia coli , Antibacterianos/farmacologia , Bangladesh/epidemiologia , Estudos Transversais , Escherichia coli , Humanos , Testes de Sensibilidade Microbiana , Prevalência , Proteus , Centros de Atenção Terciária
15.
Mymensingh Med J ; 31(1): 41-48, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34999678

RESUMO

Antimicrobial resistance mediated by extended-spectrum beta-lactamases (ESBL), AmpC beta-lactamase and metallo-beta-lactamase (MBL) producing Acinetobacter species is an emerging problem worldwide. In this cross-sectional study total 341 specimens were collected over a period of one year from January 2017 to January 2018. Specimens were collected from ICU and Surgery unit of Mymensingh Medical College Hospital, Mymensingh, Bangladesh. Specimens were collected from ICU and Surgery Unit of Mymensingh Medical College Hospital, Mymensingh, Bangladesh. Samples were processed for culture by standard conventional methods and susceptibility testing and determined by Kirby Bauer disc diffusion method. Antibiotic discs and their strength were according to the CLSI 2017 guideline. Molecular study was done to detect the species by OXA-51 gene and drug resistance genes (IMP, VIM, NDM, TEM, SHV, CTX, SPM, SIM and GIM). Species identification was done by OXA-51 gene which is intrinsic to Acinetobacter baumannii. Among the 46 isolates, 36(78.26%) were positive for Oxa-51 gene, 16(34.8%) for TEM gene, 9(19.6%) for VIM gene, 3(6.5%) for NDM gene and 1(2.2%) for IMP gene. This study gives an alarming sign towards high prevalence of cephalosporin and carbapenem resistance due to production of extended spectrum beta-lactamases and metallo-betalactamases, respectively. Early detection, proper antibiotic policies, and compliance towards infection control practices are the best defenses against these organisms.


Assuntos
Acinetobacter baumannii , Acinetobacter baumannii/genética , Antibacterianos/farmacologia , Bangladesh/epidemiologia , Estudos Transversais , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Humanos , Testes de Sensibilidade Microbiana , Centros de Atenção Terciária , beta-Lactamases/genética
16.
Mymensingh Med J ; 31(1): 94-98, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34999686

RESUMO

Among the quinolones, fluoroquinolones are broad spectrum antimicrobial agents used for treating many clinical infections including Salmonellosis. Although high level of resistance to fluoroquinolones remains low in Salmonella but reduced susceptibility is increasing worldwide. Plasmid-mediated quinolone resistance (PMQR) of qnr type (qnrA, B and S) has been identified now a day in several enterobacterial species including Salmonella spp. This cross-sectional study was held at department of Microbiology, Mymensingh Medical College, Mymensingh, Bangladesh from March 2019 to February 2020. This study was conducted to determine the current quinolone resistance pattern and to detect the presence of qnrA, qnrB and qnrS genes among Salmonella isolates. Antimicrobial susceptibility test of 36 Salmonella isolates were done by disc diffusion method. MIC of ciprofloxacin was detected by agar dilution method. Then amplification with specific primers of qnrA, qnrB and qnrS genes were performed for all Salmonella isolates. The present study observed 80.5% resistance to nalidixic acid, 33.3% to ciprofloxacin and 19.4% to ofloxacin by disc diffusion method. qnr A gene was detected in 2(5.5%) isolates, where as qnrS was detected in 5 (13.8%) isolates. None of the isolates was positive for qnrB gene. All the qnrA positive isolates showed resistance to Ciprofloxacin (MIC=128µg/ml) and Ofloxacin. In conclusion, presence of qnr genes in the study isolates is alarming, because, rapid dissemination might occur due to conjugative plasmid mediated horizontal transfer.


Assuntos
Quinolonas , Antibacterianos/farmacologia , Bangladesh , Estudos Transversais , Farmacorresistência Bacteriana/genética , Humanos , Testes de Sensibilidade Microbiana , Quinolonas/farmacologia , Salmonella/genética
17.
Mymensingh Med J ; 31(1): 180-185, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34999700

RESUMO

Rapid spread of multidrug resistant microorganisms is a matter of great concern throughout the glove including Bangladesh. The objective was to identify the causative organisms for urinary tract infection (UTI) and their sensitivity patterns to antibiotics. This descriptive cross-sectional study was conducted on patients admitted with UTI (n=60) at a tertiary level hospital in Dhaka, Bangladesh from March 2019 to September 2019. Data were collected through clinical record reviews. Data of all these 60 cases were analyzed for socio-demographic characteristics. Of the 60 patients, culture and sensitivity report was available for 42 patients. Therefore, data were further analyzed for these 42 cases. Median age of patients was 35 years and 80% were female. The main organisms isolated from urine culture of UTI patients were E. coli (64%), Klebsiella (12%) and Enterococci species (10%). Susceptibility to antibiotics was analyzed only for E. coli (n=27) since the number of isolates of other organisms were small. E. coli was found to be resistant to most of the first- and second-line antibiotics, such as Amoxicillin (100%), Amoxyclav (72%), Co-trimoxazole (89%), Nalidixic acid (78%), Ceftazidim (94%), Ceftriaxone (73%), Cefuroxime (100%), Ciprofloxacin (59%), Cephotaxime (80%), Cefixime (100%) and Moxifloxacin (100%). E. coli was the predominant organism responsible for UTI and was resistant to most of the first- and second-line antibiotics. Immediate action is needed to develop empirical guideline for empirical management of UTI and establish surveillance system for monitoring.


Assuntos
Escherichia coli , Infecções Urinárias , Adulto , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bangladesh/epidemiologia , Estudos Transversais , Farmacorresistência Bacteriana , Feminino , Humanos , Testes de Sensibilidade Microbiana , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/epidemiologia
18.
Arch Microbiol ; 204(2): 131, 2022 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-35000007

RESUMO

There is a rapid rise in the incidence of quinolone resistant bacteria in Nigeria. Most studies in Nigeria have focused on isolates from the clinical settings, with few focusing on isolates of environmental origin. This study aimed to investigate the antibiogram and carriage of plasmid-mediated quinolone resistance (PMQR) genes by quinolone-resistant isolates obtained from a pool of cefotaxime-resistant Escherichia coli (E. coli) recovered from sewage leaking out of some surface-leaking sanitary sewers in a University community in Nigeria. Isolation of E. coli from the sewage samples was done on CHROMagar E. coli, after enrichment of the samples was done in Brain Heart Infusion broth amended with 6 µg/mL of cefotaxime. Identification of presumptive E. coli was done using molecular methods (detection of uidA gene), while susceptibility to antibiotics was carried out using the disc diffusion method. Detection of PMQR genes (qnrA, qnrB, qnrS, aac(6')-lb-cr, qepA and oqxAB) was carried out using primer-specific PCR. A total of 32 non-repetitive cefotaxime-resistant E. coli were obtained from the sewage, with 21 being quinolone-resistant. The quinolone-resistant isolates showed varying level of resistance to the tested antibiotics, with imipenem being the only exception with 0% resistance. The PMQR genes: aac(6')-lb-cr, qnrA, qnrB, qnrS and qepA and oqxAB were detected in 90.5%, 61.9%, 47.6%, 38.1%, 4.8% and 0% respectively of the isolates. The findings of this study showed a high level of resistance to antibiotics and carriage of PMQR genes by quinolone-resistant E. coli obtained from the leaking sanitary sewers, suggesting a potential environmental and public health concern.


Assuntos
Escherichia coli , Quinolonas , Antibacterianos/farmacologia , Cefotaxima/farmacologia , Farmacorresistência Bacteriana/genética , Escherichia coli/genética , Humanos , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Quinolonas/farmacologia
19.
Cell Mol Life Sci ; 79(1): 63, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-35006382

RESUMO

Conventional angiogenic factors, such as vascular endothelial growth factor (VEGF), regulate both pathological and physiological angiogenesis indiscriminately, and their inhibitors may elicit adverse side effects. Secretogranin III (Scg3) was recently reported to be a diabetes-restricted VEGF-independent angiogenic factor, but the disease selectivity of Scg3 in retinopathy of prematurity (ROP), a retinal disease in preterm infants with concurrent pathological and physiological angiogenesis, was not defined. Here, using oxygen-induced retinopathy (OIR) mice, a surrogate model of ROP, we quantified an exclusive binding of Scg3 to diseased versus healthy developing neovessels that contrasted sharply with the ubiquitous binding of VEGF. Functional immunohistochemistry visualized Scg3 binding exclusively to disease-related disorganized retinal neovessels and neovascular tufts, whereas VEGF bound to both disorganized and well-organized neovessels. Homozygous deletion of the Scg3 gene showed undetectable effects on physiological retinal neovascularization but markedly reduced the severity of OIR-induced pathological angiogenesis. Furthermore, anti-Scg3 humanized antibody Fab (hFab) inhibited pathological angiogenesis with similar efficacy to anti-VEGF aflibercept. Aflibercept dose-dependently blocked physiological angiogenesis in neonatal retinas, whereas anti-Scg3 hFab was without adverse effects at any dose and supported a therapeutic window at least 10X wider than that of aflibercept. Therefore, Scg3 stringently regulates pathological but not physiological angiogenesis, and anti-Scg3 hFab satisfies essential criteria for development as a safe and effective disease-targeted anti-angiogenic therapy for ROP.


Assuntos
Inibidores da Angiogênese/farmacologia , Cromograninas/imunologia , Cromograninas/metabolismo , Neovascularização Patológica/genética , Neovascularização Retiniana/patologia , Retinopatia da Prematuridade/patologia , Animais , Capilares/metabolismo , Cromograninas/antagonistas & inibidores , Cromograninas/genética , Modelos Animais de Doenças , Fragmentos Fab das Imunoglobulinas/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oxigênio/efeitos adversos , Receptores de Fatores de Crescimento do Endotélio Vascular , Proteínas Recombinantes de Fusão/farmacologia , Neovascularização Retiniana/genética , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores
20.
Molecules ; 27(1)2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35011492

RESUMO

Before entering the cell, the SARS-CoV-2 spike glycoprotein receptor-binding domain (RBD) binds to the human angiotensin-converting enzyme 2 (hACE2) receptor. Hence, this RBD is a critical target for the development of antiviral agents. Recent studies have discovered that SARS-CoV-2 variants with mutations in the RBD have spread globally. The purpose of this in silico study was to determine the potential of a fruit bromelain-derived peptide. DYGAVNEVK. to inhibit the entry of various SARS-CoV-2 variants into human cells by targeting the hACE binding site within the RBD. Molecular docking analysis revealed that DYGAVNEVK interacts with several critical RBD binding residues responsible for the adhesion of the RBD to hACE2. Moreover, 100 ns MD simulations revealed stable interactions between DYGAVNEVK and RBD variants derived from the trajectory of root-mean-square deviation (RMSD), radius of gyration (Rg), and root-mean-square fluctuation (RMSF) analysis, as well as free binding energy calculations. Overall, our computational results indicate that DYGAVNEVK warrants further investigation as a candidate for preventing SARS-CoV-2 due to its interaction with the RBD of SARS-CoV-2 variants.


Assuntos
Enzima de Conversão de Angiotensina 2 , Bromelaínas , Simulação por Computador , Domínios e Motivos de Interação entre Proteínas , SARS-CoV-2 , Enzima de Conversão de Angiotensina 2/química , Antivirais/química , Antivirais/farmacologia , Bromelaínas/química , Bromelaínas/farmacologia , COVID-19/tratamento farmacológico , Modelos Moleculares , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Peptídeos/química , Peptídeos/farmacologia , Ligação Proteica , SARS-CoV-2/química , SARS-CoV-2/efeitos dos fármacos , Glicoproteína da Espícula de Coronavírus/química
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