Background and Aims: Reports examine quinolone resistance mechanisms among Pseudomonas spp. are sporadic in the Kingdom of Saudi Arabia (KSA). We previously examined the genetic bases of ...plasmid-mediated quinolone resistance among Pseudomonas spp. clinical isolates. This study investigated chromosomally mediated quinolone resistance mechanisms via investigation of the mutations in the gyrA and parC genes. Methods: The minimum inhibitory concentration (MIC) to different quinolones was determined. Twenty-nine quinolone resistant Pseudomonas spp. clinical isolates were included. The gyrA and parC genes were sequenced by Sanger capillary electrophoresis. Multiple sequence alignment for the translated gyrA and parC genes was performed to identify mutation sites. Results: Of the 29 isolates, 27 isolates were P. aeruginosa and two were P. putida. The cluster analysis of the quinolone susceptibility pattern revealed seven susceptibility phenotypes (A-G) based on susceptibility patterns rather than the MIC values. Also, 22 different susceptibility phenotypes were detected based on MIC values. All isolates exhibited a missense mutation at position 83 (S83I/T/F) of the gyrA gene in addition to six missense mutations at positions outside the QRDR of this gene. In addition, 82.8% (24/29) of the isolates harbored a missense mutation in the parC gene at position 87 (S87L), along with six novel mutations outside the QRDR of the parC gene. Haplotyping of the gyrA, parC, and the overall QRDR revealed six, 10, and 13 different haplotypes, respectively. Conclusion: This study documents the incidence of the commonly reported mutations in the gyrA and parC genes in addition to novel mutations in these genes among Pseudomonas spp. clinical isolates recovered from KSA. Together with our previous findings, these data provide an insight into the genetic background of quinolone resistance among Pseudomonas spp. clinical isolates in KSA. Keywords: minimum inhibitory concentration, Pseudomonas, quinolone resistance determining region, quinolones, haplotyping
Modification of chitosan (CS) by means of blending with other polymers is a convenient method to improve its physical properties for practical utilization. The similarity of cellulose and chitosan in ...primary structures might facilitate the formation of homogeneous films. Mixing cyanoethylchitosan (CECS) with cellulose acetate (CA) overcomes mechanical weakness of CS films. CECS is prepared by reaction of chitosan with acrylonitrile in the vapour phase under a different reaction conditions, namely, sodium hydroxide concentration and reaction period. Blended films of CECS and CA are made by casting from dimethylformamide (DMF) followed by impregnation in water. CECS/CA films obtained are characterized by nitrogen content, tensile strength, elongation at break, FTIR and thermogravimetric analysis (TGA). Antibacterial activity of films prepared against Gram (−ve) and Gram (+ve) bacteria is measured via both disk diffusion method and bacterial count method. Blended films show good antibacterial effects toward Gram (+ve) bacteria than Gram (−ve) ones. Antibacterial activities of blended films increased by increasing the CECS percent in the blended films while the tenacity of these films gradually decreased. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) show that CECS possesses higher effect on Gram (+ve) bacteria Staphylococcus aureus than Gram (−ve) bacteria Escherichia coli. In the meantime, CECS is much more powerful in inhibition of bacteria than CS itself.
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•A facile green chemical reduction approach was used to prepare Pd-graphene catalyst.•Raman, XPS and TEM analysis confirmed the synthesis of graphene decorated with ...Pd.•Pd/RGO-salicylic acid shows superior catalytic activity towards nitrobenzene reduction.•Pd-graphene catalyst has a remarkable turnover frequency for nitrobenzene reduction.
A facile green chemical reduction approach is developed to synthesize palladium (Pd) nanoparticles (NPs) supported on reduced graphene oxide (RGO) using exfoliated graphite oxide as a precursor with various reducing agents, including salicylic acid, oxalic acid, ascorbic acid, NaOH and hydrazine hydrate. The as-prepared catalysts were characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transfer infrared (FT-IR), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The catalytic performance has been examined for the reduction of nitrobenzene using sodium borohydride as a reducing agent under mild conditions. Our findings indicated that most of oxygen functionalities are removed using green chemical reduction approach associated with the good catalytic performance. The catalytic activity depends particularly on target concentration, catalyst loading and reaction time. The results of this research would develop a new one-pot synthesis avenue for the preparation of Pd/RGO nanocomposite materials and provides the application of Pd/RGO into the heterogeneous catalysis.
Recently one dimensional (1-D) nanostructured metal-oxides have attracted much attention because of their potential applications in gas sensors. 1-D nanostructured metal-oxides provide high surface ...to volume ratio, while maintaining good chemical and thermal stabilities with minimal power consumption and low weight. In recent years, various processing routes have been developed for the synthesis of 1-D nanostructured metal-oxides such as hydrothermal, ultrasonic irradiation, electrospinning, anodization, sol-gel, molten-salt, carbothermal reduction, solid-state chemical reaction, thermal evaporation, vapor-phase transport, aerosol, RF sputtering, molecular beam epitaxy, chemical vapor deposition, gas-phase assisted nanocarving, UV lithography and dry plasma etching. A variety of sensor fabrication processing routes have also been developed. Depending on the materials, morphology and fabrication process the performance of the sensor towards a specific gas shows a varying degree of success. This article reviews and evaluates the performance of 1-D nanostructured metal-oxide gas sensors based on ZnO, SnO(2), TiO(2), In(2)O(3), WO(x), AgVO(3), CdO, MoO(3), CuO, TeO(2) and Fe(2)O(3). Advantages and disadvantages of each sensor are summarized, along with the associated sensing mechanism. Finally, the article concludes with some future directions of research.
Cell adhesion molecules (CAMs) orchestrate leukocyte trafficking and could link peripheral and neuroinflammation in patients with severe mental illness (SMI), by promoting inflammatory and ...immune-mediated responses and mediating signals across blood-brain barrier. We hypothesized that CAMs would be dysregulated in SMI and evaluated plasma levels of different vascular and neural CAMs. Dysregulated CAMs in plasma were further evaluated in vivo in leukocytes and brain tissue and in vitro in induced pluripotent stem cells.
We compared plasma soluble levels of different vascular (VCAM-1, ICAM-1, P-SEL) and neural (JAM-A, NCAD) CAMs in circulating leukocytes in a large SMI sample of schizophrenia (SCZ) spectrum disorder (n = 895) and affective disorder (n = 737) and healthy control participants (n = 1070) controlling for age, sex, body mass index, C-reactive protein, and freezer storage time. We also evaluated messenger RNA expression of ICAM1 and related genes encoding ICAM-1 receptors in leukocytes using microarray (n = 842) and in available RNA sequencing data from the CommonMind Consortium (CMC) in postmortem samples from the dorsolateral prefrontal cortex (n = 474). The regulation of soluble ICAM-1 in induced pluripotent stem cell–derived neurons and astrocytes was assessed in patients with SCZ and healthy control participants (n = 8 of each).
Our major findings were 1) increased soluble ICAM-1 in patients with SMI compared with healthy control participants; 2) increased ITGB2 messenger RNA, encoding the beta chain of the ICAM-1 receptor, in circulating leukocytes from patients with SMI and increased prefrontal cortex messenger RNA expression of ICAM1 in SCZ; and 3) enhanced soluble ICAM-1 release in induced pluripotent stem cell–derived neurons from patients with SCZ.
Our results support a systemic and cerebral dysregulation of soluble ICAM-1 expression in SMI and especially in patients with SCZ.
We propose herein initial results to develop optimum redox mediators by the combination of computational simulation and catalytic functionalization of the core structure of vitamin K
. We aim to ...correlate the calculated energy value of the LUMO of different vitamin K
derivatives with their actual redox potential. For this, we optimized the catalytic alkylation of 1,4-naphthoquinones with a designed Ag(i)/GO catalyst and synthesized a series of molecules.
Increasing recurrence of mammalian tumors and severe side-effects of chemotherapeutic agents reduce the clinical efficacy of a large variety of anticancer agents that are currently being used. Thus, ...there is always a constant need to develop alternative or synergistic anticancer drugs with minimal side-effects. One important strategy to develop effective anticancer agents is to study into anticancer agents derived from natural sources. Anticancer agents derived from plants and their derivatives have been proven to be effective for cancer prevention and therapeutics. Vinca alkaloid and their derivatives, alone and in combination with therapeutic agents, have been used for a long time for the treatment of various types of cancers. Polyphenols form one of the most important and extensively used classes of plant-derived therapeutics for cancer prevention or chemotherapy. The present review highlights a plethora of studies focused on the antineoplastic properties of plant-derived chemicals, such as Vinca alkaloid, saponins, and flavonoids.
ABSTRACT
Fungal rhinosinusitis (FRS) is a common problem worldwide, with an increasing burden in arid climate regions.
Aspergillus
species are the most common causative agents involved. In the ...present study, we investigated the prevalence, molecular characterization, and antifungal susceptibility of opportunists causing FRS in Sudan on the basis of strains collected over a period of 5 years. β-Tubulin and calmodulin sequencing were used for species identification, and antifungal susceptibility profiles were evaluated by the protocol of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Predominant species belonged to the
Aspergillus flavus
complex (
n
= 244),
A. terreus
complex (
n
= 16),
A. fumigatus
complex (
n
= 7), and other fungi (
n
= 17). Molecular identification of 94 strains of
Aspergillus
revealed the following species:
A. flavus
(
n
= 88),
A. terreus
(
n
= 1),
A. citrinoterreus
(
n
= 2),
A. fumigatus
(
n
= 1),
A. caespitosus
(
n
= 1), and
A. sydowii
(
n
= 1). Several
A. flavus
and an
A. fumigatus
isolates showed reduced susceptibility to azoles (minimum inhibitory concentrations above the clinical breakpoints or epidemiological cutoff values). Despite several mutations revealed in
cyp51A
of these isolates, none could be directly linked to azole resistance. Molecular identification of fungi causing FRS is useful to identify cryptic species and for epidemiologic studies.
IMPORTANCE
Fungal rhinosinusitis (FRS) is a significant clinical problem in arid regions. This study provides new insights into the prevalence, etiology, and antifungal susceptibility of FRS pathogens in Sudan, where the disease burden is high.
Aspergillus
species, particularly the
A. flavus
complex, were identified as the primary FRS pathogens in the region, with some evidence of antifungal resistance. The molecular identification of fungal species causing FRS is useful for detecting antifungal resistance, identifying cryptic species, and characterizing the epidemiology of the disease. The emergence of Azole resistance
Aspergilli
in Sudan highlights the need for continued surveillance and appropriate use of antifungal agents. These findings have important implications for clinical management, public health policy, and future research on FRS. Publishing this study in Microbiology Spectrum would enable other researchers and clinicians to build on these findings, ultimately improving the diagnosis, treatment, and prevention of FRS.
Fungal rhinosinusitis (FRS) is a significant clinical problem in arid regions. This study provides new insights into the prevalence, etiology, and antifungal susceptibility of FRS pathogens in Sudan, where the disease burden is high.
Aspergillus
species, particularly the
A. flavus
complex, were identified as the primary FRS pathogens in the region, with some evidence of antifungal resistance. The molecular identification of fungal species causing FRS is useful for detecting antifungal resistance, identifying cryptic species, and characterizing the epidemiology of the disease. The emergence of Azole resistance
Aspergilli
in Sudan highlights the need for continued surveillance and appropriate use of antifungal agents. These findings have important implications for clinical management, public health policy, and future research on FRS. Publishing this study in Microbiology Spectrum would enable other researchers and clinicians to build on these findings, ultimately improving the diagnosis, treatment, and prevention of FRS.
Abstract
Background and Hypothesis
Gut microbiota alterations have been reported in severe mental illness (SMI) but fewer studies have probed for signs of gut barrier disruption and inflammation. We ...hypothesized that gut leakage of microbial products due to intestinal inflammation could contribute to systemic inflammasome activation in SMI.
Study Design
We measured plasma levels of the chemokine CCL25 and soluble mucosal vascular addressin cell adhesion molecule-1 (sMAdCAM-1) as markers of T cell homing, adhesion and inflammation in the gut, lipopolysaccharide binding protein (LBP) and intestinal fatty acid binding protein (I-FABP) as markers of bacterial translocation and gut barrier dysfunction, in a large SMI cohort (n = 567) including schizophrenia (SCZ, n = 389) and affective disorder (AFF, n = 178), relative to healthy controls (HC, n = 418). We assessed associations with plasma IL-18 and IL-18BPa and leukocyte mRNA expression of NLRP3 and NLRC4 as markers of inflammasome activation.
Study Results
Our main findings were: (1) higher levels of sMAdCAM-1 (P = .002), I-FABP (P = 7.6E−11), CCL25 (P = 9.6E−05) and LBP (P = 2.6E−04) in SMI compared to HC in age, sex, BMI, CRP and freezer storage time adjusted analysis; (2) the highest levels of sMAdCAM-1 and CCL25 (both P = 2.6E−04) were observed in SCZ and I-FABP (P = 2.5E−10) and LBP (3) in AFF; and (3), I-FABP correlated with IL-18BPa levels and LBP correlated with NLRC4.
Conclusions
Our findings support that intestinal barrier inflammation and dysfunction in SMI could contribute to systemic inflammation through inflammasome activation.
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