Microbial pathogenesis最新文献

The present study aimed to determine the presence of Klebsiella pneumoniae and Escherichia coli with extended-spectrum β-lactamase (ESBL)s property from treated wastewater effluents. Treated effluent samples were collected from two major water treatment plants which located at Avaniyapuram and Sakkimangalam, Madurai, Tamil Nadu, India. Among the 51 isolates, 56.86 % represented E. coli (18 from Avaniyapuram and 11 from Sakkimangalam) and 43.14 % were K. pneumoniae (7 from Avaniyapuram and 15 from Sakkimangalam). Based on the ESBL propensity, E. coli was overrepresented in the present study. All the isolates turned positive for ESBL, while 5.88 % of K. pneumoniae and 7.84 % of E. coli were positive for carbapenemases. Further, K. pneumoniae isolates from both sites showed 100 % resistance to beta-lactams, with resistance to other antibiotics such as tetracycline and meropenem. E. coli isolates were 100 % resistant to ceftazidime and cefuroxime, and 88.9 % were resistant to amoxicillin/clavulanate and ceftriaxone. The MAR indices observed in the present study for E. coli and K. pneumoniae were above the threshold value of 0.2 suggested a high risk of environmental contamination. These findings highlighted the need for routine surveillance at appropriate intervals for the presence of ESBL producing pathogens and other MDR pathogens in the environment to provide proper clinical management, develop various counter measures and policies to address and halt the spread of such potential threats.

The highly pathogenic Marburg virus (MARV) is a member of the Filoviridae family, a non-segmented negative-strand RNA virus. This article represents the computer-aided drug design (CADD) approach for identifying drug-like compounds that prevent the MARV virus disease by inhibiting nucleoprotein, which is responsible for their replication. This study used a wide range of in silico drug design techniques to identify potential drugs. Out of 368 natural compounds, 202 compounds passed ADMET, and molecular docking identified the top two molecules (CID: 1804018 and 5280520) with a high binding affinity of −6.77 and −6.672 kcal/mol, respectively. Both compounds showed interactions with the common amino acid residues SER_216, ARG_215, TYR_135, CYS_195, and ILE_108, which indicates that lead compounds and control ligands interact in the common active site/catalytic site of the protein. The negative binding free energies of CID: 1804018 and 5280520 were −66.01 and −31.29 kcal/mol, respectively. Two lead compounds were re-evaluated using MD modeling techniques, which confirmed CID: 1804018 as the most stable when complexed with the target protein. PC3 of the (Z)-2-(2,5-dimethoxybenzylidene)-6-(2-(4-methoxyphenyl)-2-oxoethoxy) benzofuran-3(2H)-one (CID: 1804018) was 8.74 %, whereas PC3 of the 2′-Hydroxydaidzein (CID: 5280520) was 11.25 %. In this study, (Z)-2-(2,5-dimethoxybenzylidene)-6-(2-(4-methoxyphenyl)-2-oxoethoxy) benzofuran-3(2H)-one (CID: 1804018) unveiled the significant stability of the proteins' binding site in ADMET, Molecular docking, MM-GBSA and MD simulation analysis studies, which also showed a high negative binding free energy value, confirming as the best drug candidate which is found in Angelica archangelica which may potentially inhibit the replication of MARV nucleoprotein.

Outbreaks of the foot-and-mouth disease (FMD) have major economic impact on the global livestock industry by affecting the animal health and product safety. L-protease, a non-structural protein of FMDV, is a papain-like cysteine proteinase involved in viral protein processing as well as cleavage of host proteins for promoting the virus growth. FMDV synthesizes two forms of leader proteinase, L^pro (Lab^pro and Lb^pro), where the deletion of Lab^pro is lethal and Lb^pro deletion is reported to be attenuated. Defective replicons have been used by trans-complementing the deleted gene to produce one time replicating virus; thus, the bio-safety procedure can be compromised in the production units. Attempts are made to rescue of ΔLb^proFMDV Asia1 virus by co-expressing the Lb^pro protein carried in pcDNA plasmid. Mutant FMDV cDNA, pAsia-ΔLb^pro, was constructed by PCR mediated mutagenesis using inverse primers. Transfection of BHK-21 cells with in-vitro transcribed RNA from the constructs failed to produce an infective mutant FMDV. Genetic trans-complementation of the Lb^pro, which was done by co-transfecting the pcDNALb^pro plasmid DNA along with the pAsia-ΔLb^pro RNA in BHK-21 cells also failed to produce viable virus. Expression experiments of reporter genes and indirect immune-fluorescence confirmed the production of the viral proteins in wild type FMDV pAsia^WT; however, it was absent in the pAsia-ΔLb^pro indicating that the leaderless virus was unable to produce infectious progeny and infect the cells. Failure to produce virus either by Lb^pro deleted mutant clone or by genetic complementation suggests little chance of reversion of the disabled virus with large deletions of FMDV genome.

Therapeutic management of mastitis faces significant challenges due to multidrug resistance. In the present study, multi-drug-resistant (MDR) Staphylococcus spp, Klebsiella pneumoniae, and Escherichia coli were isolated from bovine clinical mastitis cases and the phenotypic and genotypic multidrug resistance profiling was carried out. Silver nanoparticles (AgNPs) were biosynthesized using Ocimum sanctum leaf extracts and characterized via UV Vis absorption, Fourier Transform Infrared Spectroscopy, X-ray diffraction studies, Energy dispersive spectroscopy and Electron Microscopy. The determined minimum inhibitory concentration and minimum bactericidal concentration of the AgNPs against the recovered MDR isolates were 62.5 μg/ml and 125 μg/ml respectively. At a concentration of 50 μg/ml, the AgNPs demonstrated biofilm inhibitory activities of 80.35 % for MDR E. coli, 71.29 % for S. aureus and 60.18 % for MDR K. pneumoniae. Post-treatment observations revealed notable differences in biofilm formation across bacterial isolates. Furthermore, AgNP treatment led to significant downregulation of expression of the efflux pump genes acrB, acrE, acrF, and emrB in Gram-negative isolates and norB in Staphylococci isolates. This research underscores the potential for the development of an eco-friendly antimicrobial alternative in the form of green synthesized silver nanoparticles to combat drug resistance offering potential antibiofilm and efflux pump inhibitory activities.

Epinecidin-1 (Epi-1) is an antimicrobial peptide originated from fish with various pharmacological activities but carries the risk of acquiring resistance with long-term use. In the present study, we use L-lactic acid to enhance the antibacterial activity of synthesized Epi-1 against the aquaculture and food pathogen Aeromonas hydrophila. The results showed that 5.5 mmol/L lactic acid increased the inhibitory and bactericidal activity of 25 μmol/L Epi-1 against two strains of A. hydrophila. The laser confocal images proved that lactic acid pre-treatment improved the attachment efficiency of Epi-1 in A.hydrophila cells. In addition, lactic acid enhanced the damaging effect of Epi-1 on the cell membrane of A. hydrophila, evidenced by releasing more nucleic acids, proteins, and transmembrane pH ingredients decrease and electromotive force dissipation. SEM images showed that compared with the single Epi-1 treatment, the co-treatment of Epi-1 and lactic acid caused more outer membrane vesicles (OMVs) and more severe cell deformation. These findings proved that lactic acid could enhance the efficiency of Epi-1 against A. hydrophila and shed light on new aspects to avoid resistance of pathogens against Epi-1.

Background

The significant death rate of glioblastoma is well-known around the world. The link between gut microbiota and glioma is becoming more studied. The goal of this study was to look at the relationships between intestinal flora and glioblastoma, and to provide a new perspective for the diagnosis as well as treatment of glioblastoma.

Methods

Fecal samples from 80 participants with glioblastoma (n = 40) and healthy individuals (n = 40) in this study were collected as well as analyzed utilizing 16S rRNA gene amplicon sequencing in order to characterize the gut microbial community.

Results

Each group has its own microbial community, and the microbial environment of glioblastoma patients had lower richness and evenness. The structure of gut microbiota community in glioblastoma patients showed profound changes, which includes the increase of pathogens in Fusobacteria and Bacteroidetes, and the reduction of probiotic bacteria in Firmicutes, Actinobacteria and Verrucomicrobia. Meanwhile, the significant correlations and clustering of OTUS (operational taxonomic units) in glioblastoma patients were discovered, and a biomarker panel (Fusobacterium, Escherichia/Shigella, Ruminococcus gnavus group, Lachnospira, Akkermansia, Parasutterella) had been used to discriminate the patients with glioblastoma from the healthy subjects (AUC: 0.80). Furthermore, the glioblastoma group exhibited multiple disturbed pathways through KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis, particularly in genetic information processing. Moreover, the prediction of phenotypic characteristics of microbiome proposed that the glioblastoma patients might have more Gram-negative bacteria and opportunistic pathogens than the healthy controls.

Conclusions

When compared to healthy people, glioblastoma sufferers have a different host-microbe interaction. Furthermore, certain types of intestinal flora could be regarded as biomarkers and drug targets for the diagnosis as well as treatment of glioblastomas.

The toxicity of the contaminated powder contributed to toxic aflatoxins has been well-known in the literature. However, before this study, the specific fungal strain behind aflatoxin production remained unidentified. Our research aimed to isolate and identify fungi from the tainted sandwiches while also assessing the preservation of sandwiches in ambient conditions. The study pinpointed Aspergillus flavus as the fungus responsible for aflatoxin production. Analysis revealed that the sandwich samples contaminated with pure A. flavus exhibited a significant Aflatoxin B1 (AFB1) concentration of 55.2 ± 0.21 ng/g, accompanied by a spore count of 2 × 10⁶ Colony-Forming Unit (CFU)/g after ten days. In contrast, sandwich samples contaminated with the unspecified fungi displayed a lower AFB1 content of 16.21 ± 0.42 ng/g, with a spore count of 2.2 × 10² CFU/g after the same duration. In the prevention study, the efficacy of the ethanol spray method for inhibiting aflatoxin from A. flavus was investigated. Results demonstrated that a 70 % ethanol concentration at a ratio of 2.0 % total weight of the sandwich proved highly effective, significantly impeding fungal growth. This method extended the preservation time by sevenfold compared to the control. Importantly, tests at 2.0 % ethanol of the sandwich weight did not detect aflatoxin presence.

Dengue virus (DENV) infection is a worldwide public health concern infecting approximately 400 million individuals and about 40,000 mortalities yearly. Despite this, no licensed or readily available antiviral medication is currently available specifically for DENV infection, and therapy is typically symptomatic. Therefore, the objective of the study was to investigate the antiviral activity of Beta vulgaris L. phytoconstituents against DENV-2 targeting NS3 protein. The antiviral activity of phytochemicals was examined through virtual ligand-based screening, antiviral inhibition and dosage response assays, western blotting analysis and MD simulations. We conducted toxicological, and pharmacokinetic analysis to assess plant-based natural compound's efficacy, safety, and non-toxic doses. Molecular docking and MD simulation results revealed that the nonstructural protein-3 (NS3) might prove as a funamental target for Betanin and Glycine Betaine against Dengue virus. Betanin and Glycine betaine were initially studied for their non-toxic doses in HeLa, CHO, and Vero cells via MTT assay. HeLa cells were transiently transfected with cloned vector pcDNA3.1/Zeo(+)/DENV-2 NS3 along with non-toxic doses (80 μM–10 μM) of selected phytochemicals. The dose-response assay illustrated downregulated expression of DENV-2 NS3 gene after administration of Betanin (IC50 = 4.35 μM) and Glycine Betaine (IC50 = 4.49 μM). Dose response analysis of Betanin (80 μM–10 μM) depicted the significant inhibition of NS3 protein expression as well. These results suggested downregulated expression of DENV-2 NS3 at mRNA and protein level portraying the DENV replication inhibition. Based on our study findings, NS3 protease is depicted as distinctive DENV-2 inhibitor target. We will channel our study further into in vitro characterization employing the mechanistic study to understand the role of host factors in anti-flavi therapeutic.

Toxoplasma gondii (T.gondii) is an obligate intracellular protozoan that infects warm-blooded animals and has a global distribution. Acute toxoplasmosis is commonly reported in patients with acquired/congenital toxoplasmosis and immune deficiency. New methods are needed to prevent the sideffects of classical treatment. In this study, Rosuvastatin loaded chitosan nanoparticle (CH-NP-ROS) were synthesized and zeta potential and size were determined, and an MTT assay was performed to evaluate the cell toxicity on Macrophage cells (MQ) and anti-Toxoplasma activity using Trypan-blue staining by different concentrations of Rosuvastatin (ROS), and Rosuvastatin loaded chitosan nanoparticle (CH-NP-ROS). The cell viability assay demonstrated that CH-NP-ROS had lower cell toxicity (<15 %) compared to ROS (<30 %). Statistical analysis showed that CH-NP-ROS significantly killed 98.950 ± 1.344; P < 0.05) of Toxoplasma gondii tachyzoites. In vivo results of perituneal fluid showed that CH-NP significantly reduced the parasite load in the CH-NP-ROS group, compared to that in negative control group (P < 0.001). Growth inhibition rates of tachyzoites in mice receiving free ROS and CH-NP-ROS (injection and oral form) were found to be 166.125 + 4.066, 118.750 + 4.596 and 124.875 + 2.652, respectively, compared to mice in Sulfadiazine/Pyrimethamine treated group (positive control). In the infected untreated mice (control +), the mean tachyzoite counts per oil immersion field in the spleen was 8.25 respectively. The mean survival time in all the groups treated with ROS and CH-NP-ROS was longer than that in the negative control group Therefore, nanoformulation is a promising approach for the delivery and is safe for using therapeutic effects in acute toxoplasmosis.

The emergence of highly successful genetic lineages of methicillin-resistant Staphylococcus aureus (MRSA) poses a challenge in human healthcare due to increased morbidity and mortality rates. The RdJ clone (CC5-ST105-SCCmecII-t002 lineage), previously identified in Rio de Janeiro, Brazil, was linked to bloodstream infections and features a mutation in the aur gene (encoding aureolysin). Additionally, clinical isolates derived from this clone were more effective at evading monocytic immune responses. This study aimed to detect the RdJ clone among clinical MRSA isolated in Santa Catarina (SC) and examine its antimicrobial resistance and phagocytosis evasion capabilities. Our findings revealed the RdJ clone in 20 % of MRSA isolates, all exhibiting multiresistance. RdJ clone isolates from SC did not demonstrate a decreased rate of phagocytosis compared to CC5 non-RdJ isolates. Structural analysis suggests that the aur mutation is unlikely to significantly impact aureolysin activity. Genomic analysis of one isolate unveiled a genetic variant of the RdJ clone, sharing lineage and gene distribution but lacking the aur mutation. This study enhances the understanding of the clinical and epidemiologic risks associated with the RdJ clone and the biological mechanisms underlying its spreading in SC.