نتائج البحث - "Lactate dehydrogenase"

1

Involvement of a FAD-Linked Oxidase RSc0454 for Expression of the Type III Secretion System and Pathogenicity in Ralstonia solanacearum

المؤلفون: YuJian Zhou, Yasufumi Hikichi, Jing Li, Kouhei Ohnishi, Min Chen, Yong Zhang, Nan Chen, Xiaojun Shi, Liangliang Han, Jiwu Wang

المصدر: Molecular Plant-Microbe Interactions®. 34:1228-1235

مصطلحات موضوعية: Ralstonia solanacearum, Oxidase test, biology, Physiology, Succinate dehydrogenase, Bacterial pathogenesis, General Medicine, biochemical phenomena, metabolism, and nutrition, Pathogenicity, biology.organism_classification, Microbiology, Type three secretion system, chemistry.chemical_compound, chemistry, Lactate dehydrogenase, biology.protein, Agronomy and Crop Science

الوصف: Ralstonia solanacearum RSc0454 is predicted as a FAD-linked oxidase based on protein homologies, while it contains distinct domains of lactate dehydrogenase and succinate dehydrogenase. A previous study demonstrated that RSc0454 exhibits lactate dehydrogenase activity using pyruvate and NADH as substrates, and is essential for pathogenicity of R. solanacearum. Here, we genetically characterized involvement of RSc0454 on bacterial growth and expression of genes for the type III secretion system (T3SS, a pathogenicity determinant) in R. solanacearum. The RSc0454 mutant grew normally in rich medium but grew faintly in host plants, and failed to grow in minimal medium. Supplementary succinate but not lactate could substantially restore some phenotypes of RSc0454 mutants, including faint growth in host plants, diminished growth in the minimal medium, and lost pathogenicity toward host plants. Expression of T3SS genes is directly controlled by a master regulator, HrpB, and hrpB expression is positively regulated by HrpG and PrhG in parallel ways. Deletion of RSc0454 substantially reduced expression levels of hrpB and T3SS both in vitro and in planta. Moreover, RSc0454 is revealed to be required for the T3SS expression via HrpG and PrhG, although through some novel pathway, and impaired expression of these genes was not due to growth deficiency of RSc0454 mutants. RSc0454 is suggested to be important for redox balance inside cells, and supplementary NADH partially restored diminished growth of the RSc0454 mutant in the minimal medium only in the presence of succinate at some moderate concentrations, indicating that the unbalanced redox in the RSc0454 mutant might be responsible for its diminished growth in the minimal medium. Taken together, these results provide novel insights into the understanding of various biological functions of this FAD-linked oxidase RSc0454 and involvement of the redox balance on expression of the T3SS in R. solanacearum. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::b239830bb12ca27fafb6b506eb8f4ceeTest
https://doi.org/10.1094/mpmi-07-21-0168-scTest

2

Evaluating the dual reactivity on SD bioline malaria rapid diagnosis tests as a potential indicator of high parasitemia due to Plasmodium falciparum

المؤلفون: Vineeta Singh, Nathalie Amvongo-Adjia, Roger Moyou Somo, Valerie Makoge, Ngum Lesley Ngum, Roman Rodrigue Dongang Nana

المصدر: Pathog Glob Health

الوصف: The co-reactivity of the Plasmodium histidine-rich protein 2 (HRP2) and lactate dehydrogenase (pLDH) in malaria rapid diagnosis tests (mRDTs) as a potential indicator of high parasitemia linked to Plasmodium falciparum was evaluated in the reported study from Cameroon. The samples were screened for malaria using both mRDTs (SD bioline HRP2/pLDH), light microscopy and further confirmed by Plasmodium species-specific PCR assay. Of the 483 patients enrolled, 161 (33.3%) showed a reactive mRDTs amongst which 70 patients were positive by both microscopy and mRDTs with 30.0% (21/70) positive for HRP2 alone, while 70.0% (49/70) showed a dual reaction to HRP2 and pLDH parasite antigens. P. falciparum parasitemia was found to be significantly high among patients with both reactive antigens, (p

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1f4eef4b487d946c355c59e04826d90cTest
https://doi.org/10.1080/20477724.2021.1953684Test

3

Proteomic characterization of serum proteins from Atlantic salmon ( Salmo salar L.) from an outbreak with cardiomyopathy syndrome

المؤلفون: Philippe Sourd, Kim D. Thompson, Neil F. Inglis, Andrei Bordeianu, Janina Z. Costa, Jorge Del Pozo, Kevin McLean

المصدر: Journal of Fish Diseases. 44:1697-1709

الوصف: Cardiomyopathy syndrome (CMS), caused by piscine myocarditis virus (PMCV), is a serious challenge to Atlantic salmon (Salmo salar L.) aquaculture. Regrettably, husbandry techniques are the only tool to manage CMS outbreaks, and no prophylactic measures are available at present. Early diagnosis of CMS is therefore desirable, preferably with non-lethal diagnostic methods, such as serum biomarkers. To identify candidate biomarkers for CMS, the protein content of pools of sera (4 fish/pool) from salmon a CMS outbreak (3 pools) and from clinically healthy salmon (3 pools) were compared using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). Overall, seven proteins were uniquely identified in the sera of clinically healthy fish, while twenty seven proteins were unique to the sera of CMS fish. Of the latter, 24 have been associated with cardiac disease in humans. These were grouped as leakage enzymes (creatine kinase, lactate dehydrogenase, glycogen phosphorylase and carbonic anhydrase); host reaction proteins (acute phase response proteins - haptoglobin, fibrinogen, α2-macroglobulin, ceruloplasmin; and complement-related proteins); and regeneration/remodelling proteins (fibronectin, lumican and retinol). Clinical evaluation of the suitability of these proteins as biomarkers of CMS, either individually or as part of a panel, is a logical next step for the development of early diagnostic tools for CMS.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4044700cd16d4961304c910dadf9a341Test
https://doi.org/10.1111/jfd.13488Test

4

Imbalance between peptidoglycan synthases and hydrolases regulated lysis of Lactobacillus bulgaricus in batch culture

المؤلفون: Yifan Wu, Shiwei Chen, Xue Han, Lanwei Zhang, Jialei Sun, Haiyue Niu

المصدر: Archives of Microbiology. 203:4571-4578

الوصف: Lactobacillus bulgaricus is an important starter culture in the dairy industry, cell lysis is negative to the high density of this strain. This work describes the response of peptidoglycan synthases and hydrolases in Lactobacillus bulgaricus sp1.1 when pH decreasing in batch culture. First, the cell lysis was investigated by measuring the cytosolic lactate dehydrogenase released to the fermentation broth, a continuous increase in extracellular lactate dehydrogenase was observed after the lag phase in batch culture. Then, the peptidoglycan hydrolases profile analyzed using the zymogram method showed that eight proteins have the ability of peptidoglycan hydrolysis, three of the eight proteins were considered to contribute lysis of L. bulgaricus sp1.1 according to the changes and extents of peptidoglycan hydrolysis. In silico analysis showed that three putative peptidoglycan hydrolases, including N-acetylmuramyl-L-Ala amidase (protein ID: ALT46642.1), amidase (protein ID: ALT46641.1), and N-acetylmuramidase (protein ID: WP_013439201.1) were compatible with these proteins. Finally, the transcription of the three putative peptidoglycan hydrolases was upregulated in batch culture, in contrast, the expression of four peptidoglycan synthases was downregulated. These observations suggested the imbalance between peptidoglycan synthases and hydrolases involved in the lysis of Lactobacillus bulgaricus sp1.1.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::8993a080c7bdf40b36bb69a6662a234dTest
https://doi.org/10.1007/s00203-021-02433-0Test

5

Pathophysiological effects of Klebsiella pneumoniae infection on Galleria mellonella as an invertebrate model organism

المؤلفون: Serkan Sugeçti

المصدر: Archives of Microbiology. 203:3509-3517

الوصف: Klebsiella pneumoniae is an important human pathogen causing urinary tract infections and pneumonia. Due to the increase in resistant strains and being an opportunistic pathogen, it is very important to determine the virulence process, the cellular damage it causes in the host and the immunological response level of the host. In this study, invertebrate infection model Galleria mellonella larvae were used to investigate cellular damage, antioxidant response and changes in biochemical parameters due to K. pneumoniae infection. The activity of cell damage indicators alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase increased in hemolymph of G. mellonella larvae due to K. pneumoniae virulence. Creatine kinase, alkaline phosphatase, gamma glutamyl transferase and amylase activities were increased to regulate the disrupted energy metabolism due to infection. As a result of the damage caused by K. pneumoniae infection, changes occurred in the amount of non-enzymatic antioxidants, uric acid, bilirubin and albumin. Due to K. pneumoniae infection, the amount of calcium, potassium, magnesium and phosphorus altered. This study showed that G. mellonella larvae was important infection model in the investigation of infectious cell damage and physiological effects, given the opportunistic nature of the K. pneumoniae pathogen and the lack of adequate animal models.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c294e636fd9a25eba780261cd8c681abTest
https://doi.org/10.1007/s00203-021-02346-yTest

6

Metabolic Engineering of Enterobacter aerogenes for Improved 2,3-Butanediol Production by Manipulating NADH Levels and Overexpressing the Small RNA RyhB

المؤلفون: Ke Jiang, Ping Lu, Yefei Liu, Yudong Xu, Haoning Yang, Qi Shen, Jiayao Yang, Yan Wu, Fangxu Xu, Wanying Chu, Hongxin Zhao

المصدر: Frontiers in Microbiology, Vol 12 (2021)
Frontiers in Microbiology

الوصف: Biotechnological production of 2,3-butanediol (2,3-BD), a versatile platform bio-chemical and a potential biofuel, is limited due to by-product toxicity. In this study, we aimed to redirect the metabolic flux toward 2,3-BD in Enterobacter aerogenes (E. aerogenes) by increasing the intracellular NADH pool. Increasing the NADH/NAD+ ratio by knocking out the NADH dehydrogenase genes (nuoC/nuoD) enhanced 2,3-BD production by up to 67% compared with wild-type E. aerogenes. When lactate dehydrogenase (ldh) was knocked out, the yield of 2,3-BD was increased by 71.2% compared to the wild type. Metabolic flux analysis revealed that upregulated expression of the sRNA RyhB led to a noteworthy shift in metabolism. The 2,3-BD titer of the best mutant Ea-2 was almost seven times higher than that of the parent strain in a 5-L fermenter. In this study, an effective metabolic engineering strategy for improved 2,3-BD production was implemented by increasing the NADH/NAD+ ratio and blocking competing pathways.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d2efe973760d5a6e851b43d3f55c9f54Test
https://www.frontiersin.org/articles/10.3389/fmicb.2021.754306/fullTest

7

Antibacterial potential and mechanism of action of dithiocyano‐methane as a bactericidal agent for farm disinfection

المؤلفون: Qin Huabin, Ke Wenjie, L.‐M. Qin, Ying Yang, Y.‐J. Liu, Hui Yu, Chen Yanfeng, Yuansheng Tan

المصدر: Journal of Applied Microbiology. 131:647-657

الوصف: AIMS This study aimed to investigate the antibacterial ability and action mechanism of dithiocyano-methane against Aeromonas hydrophila, so as to provide a reference for its application in farm disinfection. METHODS AND RESULTS After exposing the bacteria to dithiocyano-methane, the minimum inhibitory concentration (MIC), minimum bactericide concentration (MBC), activities of alkaline phosphatase, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase and electric conductivity in bacterial suspensions were determined, transmission electron microscope images on cellular structure and SDS-PAGE profile of bacterial proteins were analysed and the expression of genes related to the above experimental observations was confirmed by real-time quantitative PCR. The MIC and MBC of dithiocyano-methane against three tested strains was 1·46 and 2·93 mg l-1 respectively. The results showed that dithiocyano-methane significantly damaged bacterial cell structure, inhibited the biosynthesis of bacterial proteins and changed the integrity and permeability of bacterial cell wall and cell membrane. CONCLUSIONS Dithiocyano-methane showed remarkable antibacterial ability against three tested strains, indicating it is a potential effective bactericidal agent for preventing animal diseases resulted from Aer. hydrophila. SIGNIFICANCE AND IMPACT OF THE STUDY To our best knowledge, this is the first report to examine the antibacterial ability and action mechanism of dithiocyano-methane against bacteria. The results demonstrate the great potential of dithiocyano-methane as a disinfectant against Aer. hydrophila in settings such as aquaculture ponds and livestock farms.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3a4ad024ba09dc6d0582649ea5bcb2fbTest
https://doi.org/10.1111/jam.14912Test

8

Antitumor effects of a Toxoplasma mutant lacking lactate dehydrogenases

المؤلفون: Yue Zhang, Ningbo Xia, Yaqiong Li, Zhou Taifang, Bang Shen

المصدر: Parasitology researchReferences. 120(9)

الوصف: "Bug as drug" is a concept recognized over a century ago and has gained significant research attention recently for fighting diseases such as immune disorders and others. Bacteria and viruses are constantly studied for this purpose, but the use of parasitic organisms is still rare. Recently, we found that Toxoplasma gondii mutants lacking two lactate dehydrogenases (ME49 Δldh1-Δldh2) were avirulent in mice but able to stimulate high levels of Th1 immunity. This outcome prompted us to determine whether Δldh mutants also displayed antitumor activities. Using a mouse melanoma model, we showed that intratumoral administration of Δldh1-Δldh2 repressed the growth of established tumors and helped to inhibit lethal tumor development in the mice. The sera of parasite-treated mice had high levels of TNF-α and INF-γ, which likely contributed to the tumor-repressing activity. We also found that chronic Toxoplasma infection, which is common in animals and humans, also led to antitumor activity. In addition, pre-existing chronic infections did not affect the antitumor efficiency of the Δldh1-Δldh2 mutant. Together, these results suggest that the attenuated T. gondii mutant Δldh1-Δldh2 has the potential to be a good antitumor therapy and provide new insights into the development of novel tumor therapeutics.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::382c16050e2a1d0b34d3ac23ad2f82bcTest
https://pubmed.ncbi.nlm.nih.gov/34405281Test

9

Aminoquinolines afford resistance to cerebral malaria in susceptible mice

المؤلفون: Neda Bauman, Olgica Djurković-Djaković, Aleksandra Uzelac, Tijana Štajner, Nataša Terzić-Jovanović, Jelena Srbljanović, Bogdan A. Šolaja, Branko Bobić, Igor Opsenica

المصدر: Journal of Global Antimicrobial Resistance, Vol 23, Iss, Pp 20-25 (2020)
Journal of Global Antimicrobial Resistance

الوصف: Objectives Malaria treatment is impeded by increasing resistance to conventional antimalarial drugs. Here we explored the activity of ten novel benzothiophene, thiophene and benzene aminoquinolines. Methods In vitro testing was performed by the lactate dehydrogenase assay in chloroquine (CQ)-sensitive Plasmodium falciparum strain 3D7 and CQ-resistant (CQR) P. falciparum strain Dd2. In vivo activity was evaluated by a modified Thompson test using C57BL/6 mice infected with Plasmodium berghei ANKA strain. Results Nine of the ten compounds had a lower 50% inhibitory concentration (IC50) than CQ against the CQR strain Dd2. Five of these compounds that were available for in vivo evaluation were shown to be non-toxic. All five compounds administered at a dose of 160 mg/kg/day for 3 days prolonged the survival of treated compared with untreated mice. Untreated control mice died by Day 7 with a mean parasitaemia of 15%. Among treated mice, a dichotomous outcome was observed, with a two-third majority of treated mice dying by Day 17 with a low mean parasitaemia of 5%, whilst one-third survived longer with a mean hyperparasitaemia of 70%; specifically, five of these mice survived a mean of 25 days, whilst two even survived past Day 31. Conclusions The significant antimalarial potential of this aminoquinoline series is illustrated by its excellent in vitro activity against the CQR P. falciparum strain and significant in vivo activity. Interestingly, compounds ClAQ7, ClAQ9 and ClAQ11 were able to confer resistance to cerebral malaria and afford a switch to hyperparasitaemia to mice prone to the neurological syndrome.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e9d25e50e5e45233c8f6574713c9b02cTest
http://www.sciencedirect.com/science/article/pii/S2213716520302022Test

10

Synthetic Dihydropyridines as Novel Antiacanthamoebic Agents

المؤلفون: Abdul Hameed, Ruqaiyyah Siddiqui, Ayaz Anwar, Muhammad Raza Shah, Naveed Ahmed Khan

المصدر: Medicinal Chemistry. 16:841-847

الوصف: Background: Acanthamoeba is an opportunistic pathogen widely spread in the environment. Acanthamoeba causes excruciating keratitis which can lead to blindness. The lack of effective drugs and its ability to form highly resistant cyst are one of the foremost limitations against successful prognosis. Current treatment involves mixture of drugs at high doses but still recurrence of infection can occur due to ineffectiveness of drugs against the cyst form. Pyridine and its natural and synthetic derivatives are potential chemotherapeutic agents due to their diverse biological activities. Objective: To study the antiamoebic effects of four novel synthetic dihydropyridine (DHP) compounds against Acanthamoeba castellanii belonging to the T4 genotype. Furthermore, to evaluate their activity against amoeba-mediated host cells cytopathogenicity as well as their cytotoxicity against human cells. Methods: Dihydropyridines were synthesized by cyclic dimerization of alkylidene malononitrile derivatives. Four analogues of functionally diverse DHPs were tested against Acanthamoeba castellanii by using amoebicidal, encystation and excystation assays. Moreover, Lactate dehydrogenase assays were carried out to study cytopathogenicity and cytotoxicity against human cells. Results: These compounds showed significant amoebicidal and cysticidal effects at 50 μM concentration, whereas, two of the DHP derivatives also significantly reduced Acanthamoebamediated host cell cytotoxicity. Moreover, these DHPs were found to have low cytotoxicity against human cells suggesting a good safety profile. Conclusion: The results suggest that DHPs have potential against Acanthamoeba especially against the more resistant cyst stage and can be assessed further for drug development.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::28e98ce476a178dc1b7634bd88fac1e0Test
https://doi.org/10.2174/1573406415666190722113412Test

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