Silver nanoparticles (AgNPs) are known to have bacteriostatic and bactericidal effects. The present study highlights the extracellular synthesis of AgNPs and its antibacterial properties. The AgNPs ...were synthesized using Pseudomonas sp. THG-LS1.4 strain which had been isolated from soil. The AgNPs were characterized by field emission-transmission electron microscopy (FE-TEM), X-ray diffraction (XRD), Fourier transform-infrared (FT-IR) spectroscopy, and particle size distribution (DLS). The AgNPs displayed maximum absorbance at 412 nm and were irregular in shape ranging from 10 to 40 nm. The XRD spectroscopy results demonstrated the crystalline nature of nanoparticles. The AgNPs showed antimicrobial activity against Bacillus cereus, Staphylococcus aureus, Candida tropicalis, Vibrio parahaemolyticus, Escherichia coli and Pseudomonas aeruginosa. Furthermore, the AgNPs were also evaluated for their increased antibacterial activities with various antibiotics against Escherichia coli, Pseudomonas aeruginosa and Salmonella enterica. Additionally, AgNPs showd biofilm inhibition activity. The biosynthesized AgNPs were found to be a potent agent against tested pathogens. More importantly, we highlight the applications of AgNPs as an antimicrobial agent.
Viral infections remain a global public health concern and cause a severe societal and economic burden. At the organismal level, the innate immune system is essential for the detection of viruses and ...constitutes the first line of defense. Viral components are sensed by host pattern recognition receptors (PRRs). PRRs can be further classified based on their localization into Toll-like receptors (TLRs), C-type lectin receptors (CLR), retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs), NOD-like receptors (NLRs) and cytosolic DNA sensors (CDS). TLR and RLR signaling results in production of type I interferons (IFNα and -β) and pro-inflammatory cytokines in a cell-specific manner, whereas NLR signaling leads to the production of interleukin-1 family proteins. On the other hand, CLRs are capable of sensing glycans present in viral pathogens, which can induce phagocytic, endocytic, antimicrobial, and pro- inflammatory responses. Peripheral immune sensing of viruses and the ensuing cytokine response can significantly affect the central nervous system (CNS). But viruses can also directly enter the CNS via a multitude of routes, such as the nasal epithelium, along nerve fibers connecting to the periphery and as cargo of infiltrating infected cells passing through the blood brain barrier, triggering innate immune sensing and cytokine responses directly in the CNS. Here, we review mechanisms of viral immune sensing and currently recognized consequences for the CNS of innate immune responses to viruses.
(
) is the causative agent of human tuberculosis (TB) which primarily infects the macrophages. Nearly a quarter of the world's population is infected latently by
. Only around 5%-10% of those ...infected develop active TB disease, particularly during suppressed host immune conditions or comorbidity such as HIV, hinting toward the heterogeneity of
infection. The aerosolized
first reaches the lungs, and the resident alveolar macrophages (AMs) are among the first cells to encounter the
infection. Evidence suggests that early clearance of
infection is associated with robust innate immune responses in resident macrophages. In addition to lung-resident macrophage subsets, the recruited monocytes and monocyte-derived macrophages (MDMs) have been suggested to have a protective role during
infection.
, by virtue of its unique cell surface lipids and secreted protein effectors, can evade killing by the innate immune cells and preferentially establish a niche within the AMs. Continuous efforts to delineate the determinants of host defense mechanisms have brought to the center stage the crucial role of macrophage phenotypical variations for functional adaptations in TB. The morphological and functional heterogeneity and plasticity of the macrophages aid in confining the dissemination of
However, during a suppressed or hyperactivated immune state, the
virulence factors can affect macrophage homeostasis which may skew to favor pathogen growth, causing active TB. This mini-review is aimed at summarizing the interplay of
pathomechanisms in the macrophages and the implications of macrophage heterogeneity and plasticity during
infection.
Counting cells is a cornerstone of tracking disease progression in neuroscience. A common approach for this process is having trained researchers individually select and count cells within an image, ...which is not only difficult to standardize but also very time-consuming. While tools exist to automatically count cells in images, the accuracy and accessibility of such tools can be improved. Thus, we introduce a novel tool ACCT: Automatic Cell Counting with Trainable Weka Segmentation which allows for flexible automatic cell counting via object segmentation after user-driven training. ACCT is demonstrated with a comparative analysis of publicly available images of neurons and an in-house dataset of immunofluorescence-stained microglia cells. For comparison, both datasets were manually counted to demonstrate the applicability of ACCT as an accessible means to automatically quantify cells in a precise manner without the need for computing clusters or advanced data preparation.
The strain Bhargavaea indica DC1 isolated from four-year-old P. ginseng rhizospheric soil was used to perform rapid and extracellular biosynthesis of anisotropic silver nanoparticles. The ...ultraviolet-visible (UV-vis) spectra of the reaction mixture containing silver nanoparticles showed a peak at 460 nm, corresponding to the surface plasmon absorbance of silver nanoparticles. Field-emission transmission electron microscopy (FE-TEM) structural characterization revealed the nanobar, pentagon, spherical, icosahedron, hexagonal, truncated triangle, and triangular nanoparticles, with the size range from 30 to 100 nm. The energy-dispersive X-ray (EDX) analysis and elemental mapping results also confirmed that the silver was the predominant component of isolated nanoparticles. The X-ray diffraction (XRD) results correspond to the purity of silver nanoparticles and dynamic light scattering (DLS) result indicated that the average diameter of particles was 111.6 nm. In addition, enhancement in antimicrobial activity of commercial antibiotics was observed against various pathogenic microorganisms such as Vibrio parahaemolyticus, Salmonella enterica, Staphylococcus aureus, Bacillus anthracis, Bacillus cereus, Escherichia coli, and Candida albicans.
HIV-1 infection remains a major public health concern despite effective combination antiretroviral therapy (cART). The virus enters the central nervous system (CNS) early in infection and continues ...to cause HIV-associated neurocognitive disorders (HAND). The pathogenic mechanisms of HIV-associated brain injury remain incompletely understood. Since HIV-1 activates the type I interferon system, which signals via interferon-α receptor (IFNAR) 1 and 2, this study investigated the potential role of IFNAR1 in HIV-induced neurotoxicity.
We cross-bred HIVgp120-transgenic (tg) and IFNAR1 knockout (IFNAR1KO) mice. At 11-14 months of age, we performed a behavioral assessment and subsequently analyzed neuropathological alterations using deconvolution and quantitative immunofluorescence microscopy, quantitative RT-PCR, and bioinformatics. Western blotting of brain lysates and an in vitro neurotoxicity assay were employed for analysis of cellular signaling pathways.
We show that IFNAR1KO results in partial, sex-dependent protection from neuronal injury and behavioral deficits in a transgenic model of HIV-induced brain injury. The IFNAR1KO rescues spatial memory and ameliorates loss of presynaptic terminals preferentially in female HIVgp120tg mice. Similarly, expression of genes involved in neurotransmission reveals sex-dependent effects of IFNAR1KO and HIVgp120. In contrast, IFNAR1-deficiency, independent of sex, limits damage to neuronal dendrites, microgliosis, and activation of p38 MAPK and restores ERK activity in the HIVgp120tg brain. In vitro, inhibition of p38 MAPK abrogates neurotoxicity caused similarly by blockade of ERK kinase and HIVgp120.
Our findings indicate that IFNAR1 plays a pivotal role in both sex-dependent and independent processes of neuronal injury and behavioral impairment triggered by HIV-1.
A novel strain DCY105
T
was isolated from soil collected from the rhizosphere of ginseng (
Panax ginseng
), in Gochang, Republic of Korea. Strain DCY105
T
is Gram-reaction-negative, white, ...non-motile, non-flagellate, rod-shaped and aerobic. The bacteria grow optimally at 30°C, pH 6.5–7.0 and in the absence of NaCl. Phylogenetically, strain DCY105
T
is most closely related to
Achromobacter marplatensis
LMG 26219
T
(96.81%). The DNA G+C content of strain DCY105
T
was 64.4 mol%. Ubiquinone 8 was the major respiratory quinone, and phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol were amongst the major polar lipids. C
16:00
, C
8:0
3OH and iso-C
17:0
3OH were identified as the major fatty acids present in DCY105
T
. The results of physiological and biochemical tests allowed strain DCY105
T
to be differentiated phenotypically from other recognized species belonging to the genus
Achromobacter
. Therefore, it is suggested that the newly isolated organism represents a novel species, for which the name
Achromobacter panacis
sp. nov. is proposed with the type strain designated as DCY105
T
(=CCTCCAB 2015193
T
=KCTC 42751
T
).
A Gram-stain-negative, aerobic, motile and rod-shaped strain, THG-DN7.3T, was isolated from a waterfall. Strain THG-DN7.3T grew well at 18-28 °C and at pH 6.0-7.5 on Reasoner's 2A agar. Based on 16S ...rRNA gene sequence comparisons, strain THG-DN7.3T was most closely related to Undibacterium jejuense JS4-4T (97.3 % 16S rRNA gene sequence similarity) and Undibacterium seohonense SHS5-24T (96.5 %). The G+C content of the genomic DNA was 57.4 mol%. The mean DNA-DNA relatedness of strain THG-DN7.3T with U. jejuense KACC 12607T was 40 ± 1 % (reciprocal 50 ± 2.1 %). The major cellular fatty acids of strain THG-DN7.3T were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) (47.4 %), C16 : 0 (30.4 %), summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c) (6.8 %) and C12 : 0 (6.2 %). The predominant isoprenoid quinone was ubiquinone-8. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The results of the DNA-DNA hybridization and genotypic analysis, in combination with chemotaxonomic and physiological data, demonstrated that strain THG-DN7.3T represents a novel species of the genus Undibacterium, for which the name Undibacterium aquatile sp. nov. is proposed. The type strain is THG-DN7.3T ( = KCTC 42243T = CCTCC AB 2015119T).
Biogenic synthesis of silver (AgNPs) and gold nanoparticles (AuNPs) using aqueous extract of Euphrasia officinalis has been reported. Stable AgNPs and AuNPs were formed on adding aqueous solutions of ...silver nitrate and chloroauric acid with E. officinalis leaf extract, in 19 min and 2 min, respectively. The synthesis method used in present study was simple, reliable, rapid, cost effective and ecofriendly. The synthesized nanoparticles were characterized with field emission transmission electron microscopy (FE-TEM), elemental mapping, selected area diffraction pattern (SAED), energy-dispersive X-ray spectroscopy (EDS), X-ray diffractometer (XRD), particle size distribution, zeta potential and Fourier-transform infrared spectroscopy (FTIR). The UV-Vis spectrum confirmed the synthesis of nanoparticles as the absorption band was observed at 450 nm for AgNPs and at 558 nm for AuNPs. The TEM images revealed quasi-spherical shape of AgNPs and AuNPs. The size of nanoparticles was determined to be 40.37 ± 1.8 nm for AgNPs and 49.72 ± 1.2 nm for AuNPs. The zeta potential value demonstrated the negative surface charge and stable nature of nanoparticles. Crystalline nature of the nanoparticles in the face-centred cubic (fcc) structure was confirmed by the peaks in the XRD pattern and SAED pattern. FTIR results showed the functional groups involved in reduction of silver and gold ions to metal nanoparticles. For biomedical application, the nanoparticles have been explored for anticancer, antibacterial and biofilm inhibition activities. It was observed that AgNPs exert anticancer activity against human lung cancer (A549) and human cervical cancer (HeLa) cell lines. On the other hand, AuNPs were able to inhibit only human cervical cancer cells. Furthermore, the AgNPs were active against clinically isolated human pathogens like Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Vibrio parahaemolyticus. Additionally, AgNPs also showed biofilm inhibition activity against S. aureus and P. aeruginosa.
PDF
