Regulation of overexpressed efflux pump encoding genes by cinnamon oil and trimethoprim to abolish carbapenem-resistant Acinetobacter baumannii clinical strains.

Resistance mechanisms are a shelter for Acinetobacter baumannii to adapt to our environment which causes difficulty for the infections to be treated and WHO declares this organism on the top of pathogens priority for new drug development. The most common mechanism that develops drug resistance is the overexpression of the efflux pump, especially Resistance-nodulation-cell division (RND) family, to almost most antibiotics. The study is designed to detect RND efflux pump genes in A. baumannii, and its correlation to multidrug resistance, in particular, the carbapenems resistance Acinetobacter baumannii (CRAB), and using different inhibitors that restore the antibiotic susceptibility of imipenem. Clinical A. baumannii isolates were recovered from different Egyptian hospitals in Intensive care unit (ICU). The expression of genes in two strains was analyzed using RT-PCR before and after inhibitor treatment. About 100 clinical A. baumannii isolates were recovered and identified and recorded as MDR strains with 75% strains resistant to imipenem. adeB, adeC, adeK, and adeJ were detected in thirty- seven the carbapenems resistance Acinetobacter baumannii (CRAB) strains. Cinnamomum verum oil, Trimethoprim, and Omeprazole was promising inhibitor against 90% of the carbapenems resistance Acinetobacter baumannii (CRAB) strains with a 2-6-fold decrease in imipenem MIC. Downregulation of four genes was associated with the addition of those inhibitors to imipenem for two the carbapenems resistance Acinetobacter baumannii (CRAB) (ACN15 and ACN99) strains, and the effect was confirmed in 24 h killing kinetics. Our investigation points to the carbapenems resistance Acinetobacter baumannii (CRAB) strain's prevalence in Egyptian hospitals with the idea to revive the imipenem activity using natural and chemical drugs as inhibitors that possessed high synergistic activity.

In Vivo and in Vitro activity of colistin-conjugated bimetallic silver-copper oxide nanoparticles against Pandrug-resistant Pseudomonas aeruginosa.

BACKGROUND: Addressing microbial resistance urgently calls for alternative treatment options. This study investigates the impact of a bimetallic formulation containing colistin, silver, and copper oxide on a pandrug-resistant, highly virulent Pseudomonas aeruginosa (P. aeruginosa) isolate from a cancer patient at the National Cancer Institute, Cairo University, Egypt. METHODS: Silver nanoparticles (Ag NPs), copper oxide nanoparticles (CuO NPs), and bimetallic silver-copper oxide nanoparticles (Ag-CuO NPs) were synthesized using gamma rays, combined with colistin (Col), and characterized by various analytical methods. The antimicrobial activity of Col-Ag NPs, Col-CuO NPs, and bimetallic Col-Ag-CuO NPs against P. aeruginosa was evaluated using the agar well diffusion method, and their minimum inhibitory concentration (MIC) was determined using broth microdilution. Virulence factors such as pyocyanin production, swarming motility, and biofilm formation were assessed before and after treatment with bimetallic Col-Ag-CuO NPs. The in vivo efficacy was evaluated using the Galleria mellonella model, and antibacterial mechanism were examined through membrane leakage assay. RESULTS: The optimal synthesis of Ag NPs occurred at a gamma ray dose of 15.0 kGy, with the highest optical density (OD) of 2.4 at 375 nm. Similarly, CuO NPs had an optimal dose of 15.0 kGy, with an OD of 1.5 at 330 nm. Bimetallic Ag-CuO NPs were most potent at 15.0 kGy, yielding an OD of 1.9 at 425 nm. The MIC of colistin was significantly reduced when combined with nanoparticles: 8 µg/mL for colistin alone, 0.046 µg/mL for Col-Ag NPs, and 0.0117 µg/mL for Col-Ag-CuO NPs. Bimetallic Col-Ag-CuO NPs reduced the MIC four-fold compared to Col-Ag NPs. Increasing the sub-inhibitory concentration of bimetallic nanoparticles from 0.29 × 10-2 to 0.58 × 10-2 µg/mL reduced P. aeruginosa swarming by 32-64% and twitching motility by 34-97%. At these concentrations, pyocyanin production decreased by 39-58%, and biofilm formation was inhibited by 33-48%. The nanoparticles were non-toxic to Galleria mellonella, showing 100% survival by day 3, similar to the saline-treated group. CONCLUSIONS: The synthesis of bimetallic Ag-CuO NPs conjugated with colistin presents a promising alternative treatment for combating the challenging P. aeruginosa pathogen in hospital settings. Further research is needed to explore and elucidate the mechanisms underlying the inhibitory effects of colistin-bimetallic Ag-CuO NPs on microbial persistence and dissemination.

Unveiling biological activities of biosynthesized starch/silver-selenium nanocomposite using Cladosporium cladosporioides CBS 174.62.

BACKGROUND AND OBJECTIVES: Microbial cells capability to tolerate the effect of various antimicrobial classes represent a major worldwide health concern. The flexible and multi-components nanocomposites have enhanced physicochemical characters with several improved properties. Thus, different biological activities of biosynthesized starch/silver-selenium nanocomposite (St/Ag-Se NC) were assessed. METHODOLOGY: The St/Ag-Se NC was biosynthesized using Cladosporium cladosporioides CBS 174.62 (C. cladosporioides) strain. The shape and average particle size were investigated using scanning electron microscope (SEM) and high-resolution transmission electron microscope (HR-TEM), respectively. On the other hand, the St/Ag-Se NC effect on two cancer cell lines and red blood cells (RBCs) was evaluated and its hydrogen peroxide (H2O2) scavenging effect was assessed. Moreover, its effects on various microbial species in both planktonic and biofilm growth forms were examined. RESULTS: The St/Ag-Se NC was successfully biosynthesized with oval and spherical shape and a mean particle diameter of 67.87 nm as confirmed by the HR-TEM analysis. St/Ag-Se NC showed promising anticancer activity toward human colorectal carcinoma (HCT-116) and human breast cancer (MCF-7) cell lines where IC50 were 21.37 and 19.98 µg/ml, respectively. Similarly, little effect on RBCs was observed with low nanocomposite concentration. As well, the highest nanocomposite H2O2 scavenging activity (42.84%) was recorded at a concentration of 2 mg/ml. Additionally, Staphylococcus epidermidis (S. epidermidis) ATCC 12,228 and Candida albicans (C. albicans) ATCC 10,231 were the highly affected bacterial and fungal strains with minimum inhibitory concentrations (MICs) of 18.75 and 50 µg/ml, respectively. Moreover, the noticeable effect of St/Ag-Se NC on microbial biofilm was concentration dependent. A high biofilm suppression percentage, 87.5% and 68.05%, were recorded with S. epidermidis and Staphylococcus aureus (S. aureus) when exposed to 1 mg/ml and 0.5 mg/ml, respectively. CONCLUSION: The biosynthesized St/Ag-Se NC showed excellent antioxidant activity, haemocompatibility, and anti-proliferative effect at low concentrations. Also, it exhibited promising antimicrobial and antibiofilm activities.

Aspergillus fumigatus-induced biogenic silver nanoparticles' efficacy as antimicrobial and antibiofilm agents with potential anticancer activity: An in vitro investigation.

A worldwide hazard to human health is posed by the growth of pathogenic bacteria that have contaminated fresh, processed, cereal, and seed products in storage facilities. As the number of multidrug-resistant (MDR) pathogenic microorganisms rises, we must find safe, and effective antimicrobials. The use of green synthesis of nanoparticles to combat microbial pathogens has gained a rising interest. The current study showed that Aspergillus fumigatus was applied as a promising biomass for the green synthesis of biogenic silver nanoparticles (Ag NPs). The UV-visible spectra of biosynthesized Ag NPs appeared characteristic surface plasmon absorption at 475 nm, round-shaped with sizes ranging from 17.11 to 75.54 nm and an average size of 50.37 ± 2.3 nm. In vitro tests were conducted to evaluate the antibacterial, antioxidant, and anticancer effects of various treatment procedures for Ag NP applications. The synthesized Ag NPs was revealed antimicrobial activity against Aspergillus flauvas, A. niger, Bacillus cereus, Candida albicans, Esherichia coli, Pseudomonas aerugonosa, and Staphylococcus aureus under optimum conditions. The tested bacteria were sensitive to low Ag NPs concentrations (5, 10, 11, 8, 7, 10, and 7 mg/mL) which was observed for the mentioned-before tested microorganisms, respectively. The tested bacterial pathogens experienced their biofilm formation effectively suppressed by Ag NPs at sub-inhibitory doses. Antibacterial reaction mechanism of Ag NPs were tested using scanning electron microscopy (SEM) to verify their antibacterial efficacy towards S. aureus and P. aeruginosa. These findings clearly show how harmful Ag NPs are to pathogenic bacteria. The synthesized Ag NPs showed antitumor activity with IC50 at 5 µg/mL against human HepG-2 and MCF-7 cellular carcinoma cells, while 50 mg/mL was required to induce 70 % of normal Vero cell mortality. These findings imply that green synthetic Ag NPs can be used on cancer cell lines in vitro for anticancer effect beside their potential as a lethal factor against some tested pathogenic microbes.

Induction of tomato plant biochemical immune responses by the synthesized zinc oxide nanoparticles against wilt-induced Fusarium oxysporum.

The current study used zinc oxide nanoparticles (ZnO-NPs) to protect the tomato plant against Fusarium wilt. Gamma rays were used to synthesize ZnO-NPs, and the designed ZnO-NPs were characterized using high-resolution transmission electron microscopy (HRTEM), scanning electron microscope (SEM), dynamic light scattering (DLS), energy-dispersive X-ray spectroscopy (EDX), and ultraviolet-visible (UV-Vis.) spectroscopy. We found that the 20 kGy dose is the most effective for ZnO-NPs synthesis, with the highest O.D. = 1.65 (diluted 3 times) at 400 nm. The scale of ZnO-NPs ranged from 10.45 to 75.25 nm with an average diameter of 40.20 nm. The results showed that the designed ZnO-NPs showed promising activity as a potent inducer of plant physiological immunity against Fusarium wilt disease. Likewise, ZnO-NPs significantly reduced the wilt disease symptoms incidence by 28.57% and high protection by 67.99% against F. oxysporum. Additionally, infected tomato plants treated with ZnO-NPs show improved shoot length (44.71%), root length (40.0%), number of leaves (60.0 %), chlorophyll a (36.93%), chlorophyll b (16.46%), and carotenoids (21.87%) versus infected plants. Notably, in the treatment of tomato seedlings, the beneficial effects of ZnO-NPs extended to increase not only in osmolyte contents but also total phenol contents in comparison with control plants. In conclusion, the designed ZnO-NPs can control Fusarium wilt disease and improve and develop biochemical compounds responsible for defense against fusarial infection.

Novel nanoconjugates of metal oxides and natural red pigment from the endophyte Monascus ruber using solid-state fermentation.

BACKGROUND: Antimicrobial resistance has emerged as a major global health threat, necessitating the urgent development of new antimicrobials through innovative methods to combat the rising prevalence of resistant microbes. With this view, we developed three novel nanoconjugates using microbial natural pigment for effective application against certain pathogenic microbes. RESULTS: A natural red pigment (RP) extracted from the endophyte Monascus ruber and gamma rays were applied to synthesize RP-ZnO, RP-CuO, and RP-MgO nanoconjugates. The synthesized nanoconjugates were characterized by different techniques to study their properties. The antimicrobial potential of these nanoconjugates was evaluated. Moreover, the antibiofilm, protein leakage, growth curve, and UV light irradiation effect of the synthesized nanoconjugates were also studied. Our results confirmed the nano-size, shape, and stability of the prepared conjugates. RP-ZnO, RP-CuO, and RP-MgO nanoconjugates showed broad antimicrobial potential against the tested bacterial and fungal pathogens. Furthermore, the RP-ZnO nanoconjugate possessed the highest activity, followed by the RP-CuO against the tested microbes. The highest % inhibition of biofilm formation by the RP-ZnO nanoconjugate. Membrane leakage of E. coli and S. aureus by RP-ZnO nanoconjugate was more effective than RP-MgO and RP-CuO nanoconjugates. Finally, UV light irradiation intensified the antibiotic action of the three nanoconjugates and RP-ZnO potential was greater than that of the RP-MgO, and RP-CuO nanoconjugates. CONCLUSION: These findings pave the way for exploiting the synthesized nanoconjugates as potential materials in biomedical applications, promoting natural, green, and eco-friendly approaches.

Synthesis, theoretical studies, antibacterial, and antibiofilm activities of novel azo-azomethine chelates against the pathogenic bacterium Proteus mirabilis.

2-((1-(4-((2,4,6-trioxohexahydropyrimidin-5-yl)diazenyl) phenyl) ethylidene) amino) benzoic acid (H3L), and its V(IV), Co(II), Ni(II), Cu(II), Pd(II) and Ag(I) chelates were synthesized. They were defined using multiple spectral and analytical techniques. With the exception of Ag(I) chelate, all chelates possessed non-electrolytic character. Square pyramidal shape was proposed for V(IV) chelate and Square planar for the other chelates. The analysis of functional group bands of H3L and its coordination compounds alludes that H3L chelated as neutral tetradentate via nitrogen atoms of azo and azomethine groups, oxygen atom of carbonyl of barbituric acid and OH of the carboxylic group. TG/DTG predicted the thermal behaviors of all compounds. The antibacterial activity of H3L and its coordination compounds was conducted against Proteus mirabilis at concentrations of 250, 500, and 1000 µg/mL. Ag(I) at 1000 µg/mL, showed the most inhibiting potency against P. mirabilis and registered zone of inhibition of 28.33 ± 0.84 mm and highest biofilm inhibition of 70.31%. At 50 Gy of gamma irradiation, the reducing effect of Ag(I) chelate was improved. The protein interruption of P. mirabilis was greatly interrupted by increasing the concentration of the chaletes. Also, Ag(I) showed the highest cytotoxicity with IC50 value of 11.5 µg/ mL. The novelty of this study is the synthesis of a new azo-Schiff base and this is almost the first publication of the effect of azo-Schiff ligands against that bacterial strain P. mirabilis.

Assessment of biochemical biomarkers and environmental stress indicators in some freshwater fish.

The mechanism by which an organism can adapt to subtle environmental changes is predicated on modifications to biochemical processes within the cellular metabolism in response to such changes. Changes in these processes have the potential to induce alterations in cellular structures and tissue organization, as well as establish a causal link between fluctuations in these parameters and stressors exposure. This investigation's main goal and innovation is to evaluate the environmental stress indicators in the aquatic ecosystem of Lake Qarun. Pesticide residues in freshwater fish should be the primary focus of evaluation of environmental stressor concentrations, since they serve as bioindicators at different times and places on a spatiotemporal scale. A thorough analysis of suggestive biochemical biomarker reactions should also be conducted. The effects of environmental stressors, specifically pesticide contamination in Qarun Lake, have been observed and investigated in relation to two fish species: Solea aejabtiaca and Oreochronis niloticus. The results of a hazard assessment conducted at six sampling sites using spatio-temporal data revealed elevated mean values for the pesticides, persistent organic pollutants (POPs), organochlorines, organophosphates, and pyrethroids that were detected. A multi biomarker approach facilitates a more comprehensive understanding of stress responses induced by exposure to pollutants. As a result, the activities of the biochemical biomarkers CYP-450, GST, GSH, and LDH in the blood and liver of fish samples were found to be notably elevated. The suitability of the identified variables for biomonitoring of aquatic pollution was validated, and the data unveiled variations in sensitivity among species, implying that Nile tilapia could potentially function as a bioindicator with high sensitivity. The findings were correlated with the concentrations of detrimental organochlorines, organophosphorus, and pyrethroids in the muscles and gills. The data indicates that pollutants linked to agricultural wastes, runoff, and municipal effluent may be discharged into the lake ecosystem. Consequently, to safeguard the environment, it is essential to enforce and implement policies, acts, and regulations that already exist. Assessing the effects of additional environmental stressors on aquatic ecosystems is another way in which biomarker screening with an integrative approach improves our comprehension of how toxicants impact various levels of biological organization and is particularly useful in realistic environmental exposure scenarios.

Gamma rays-assisted bacterial synthesis of bimetallic silver-selenium nanoparticles: powerful antimicrobial, antibiofilm, antioxidant, and photocatalytic activities.

BACKGROUND: Bimetallic nanoparticles (BNPs) has drawn a lot of attention especially during the last couple of decades. A bimetallic nanoparticle stands for a combination of two different metals that exhibit several new and improved physicochemical properties. Therefore, the green synthesis and design of bimetallic nanoparticles is a field worth exploring. METHODS: In this study, we present a green synthesis of silver nanoparticles (Ag NPs), selenium (Se) NPs, and bimetallic Ag-Se NPs using Gamma irradiation and utilizing a bacterial filtrate of Bacillus paramycoides. Different Techniques such as UV-Vis., XRD, DLS, SEM, EDX, and HR-TEM, were employed for identifying the synthesized NPs. The antimicrobial and antibiofilm activities of both the Ag/Se monometallic and bimetallic Ag-Se NPs were evaluated against some standard microbial strains including, Aspergillus brasiliensis ATCC16404, Candida albicans ATCC10231, Alternaria alternate EUM108, Fusarium oxysporum EUM37, Escherichia coli ATCC11229, Bacillus cereus ATCC15442, Klebsiella pneumoniae ATCC13883, Bacillus subtilis ATCC15442, and Pseudomonas aeruginosa ATCC6538 as a model tested pathogenic microbes. The individual free radical scavenging potentials of the synthesized Ag NPs, Se NPs, and bimetallic Ag-Se NPs were determined using the DPPH radical scavenging assay. The degradation of methylene blue (MB) dye in the presence of the synthesized Ag NPs, Se NPs, and bimetallic Ag-Se NPs was used to assess their photocatalytic behavior. RESULTS: According to the UV-Vis. spectrophotometer, the dose of 20.0 kGy that results in Ag NPs with the highest O.D. = 3.19 at 390 nm is the most effective dose. In a similar vein, the optimal dose for the synthesis of Se NPs was 15.0 kGy dose with O.D. = 1.74 at 460 nm. With a high O.D. of 2.79 at 395 nm, the most potent dose for the formation of bimetallic Ag-Se NPs is 15.0 kGy. The recorded MIC-values for Ag-Se NPs were 62.5 µg mL- 1, and the data clearly demonstrated that C. albicans was the organism that was most susceptible to the three types of NPs. The MIC value was 125 µg mL- 1 for both Ag NPs and Se NPs. In antibiofilm assay, 5 µg mL- 1 Ag-Se NPs inhibited C. albicans with a percentage of 90.88%, E. coli with a percentage of 90.70%, and S. aureus with a percentage of 90.62%. The synthesized NPs can be arranged as follows in decreasing order of antioxidant capacity as an antioxidant result: Ag-Se NPs > Se NPs > Ag NPs. The MB dye degradation in the presence of the synthesized Ag NPs, Se NPs, and bimetallic Ag-Se NPs was confirmed by the decrease in the measured absorbance (at 664 nm) after 20 min of exposure to sunlight. CONCLUSION: Our study provides insight towards the synthesis of bimetallic NPs through green methodologies, to develop synergistic combinatorial antimicrobials with possible applications in the treatment of infectious diseases caused by clinically and industrial relevant drug-resistant strains.

Detection of hemolytic Shiga toxin-producing Escherichia coli in fresh vegetables and efficiency of phytogenically synthesized silver nanoparticles by Syzygium aromaticum extract and gamma radiation against isolated pathogens.

BACKGROUND: Shiga toxin-producing E. coli (STEC) is a major cause of foodborne diseases accompanied by several clinical illnesses in humans. This research aimed to isolate, identify, and combat STEC using novel alternative treatments, researchers have lately investigated using plant extract to produce nanoparticles in an environmentally acceptable way. At various gamma-ray doses, gamma irradiation is used to optimize the conditions for the biogenically synthesized silver nanoparticles (Ag NPs) using an aqueous extract of clove as a reducing and stabilizing agent. METHODS: On a specific medium, 120 vegetable samples were screened to isolate STEC and molecularly identified using real-time PCR. Moreover, the antibacterial and antibiofilm activities of biogenically synthesized Ag NPs against the isolated STEC were examined. RESULTS: Twenty-five out of 120 samples of eight types of fresh vegetables tested positive for E. coli, as confirmed by 16S rRNA, of which three were positive for the presence of Stx-coding genes, and six were partially hemolytic. Seven antibiotic disks were used to determine antibiotic susceptibility; the results indicated that isolate STX2EC had the highest antibiotic resistance. The results demonstrated that Ag NPs were highly effective against the STEC isolates, particularly the isolate with the highest drug resistance, with inhibition zones recorded as 19 mm for STX2EC, 11 mm for STX1EC1, and 10 mm for STX1EC2 at a concentration of 108 µg/mL. MICs of the isolates STX1EC1, and STX1EC2 were 13.5 µg/mL whereas it was detected as 6.75 µg/mL for STX2EC. The percentages of biofilm inhibition for STX1EC2, STX1EC1, and STX2EC, were 78.7%, 76.9%, and 71.19%, respectively. CONCLUSION: These findings suggest that the biogenic Ag NPs can be utilized as a new promising antibacterial agent to combat biofouling on surfaces.

Potential antibacterial, antibiofilm, and photocatalytic performance of gamma-irradiated novel nanocomposite for enhanced disinfection applications with an investigated reaction mechanism.

BACKGROUND: Water scarcity is now a global challenge due to the population growth and the limited amount of available potable water. In addition, modern industrialization, and microbial pathogenesis is resulting in water pollution on a large scale. METHODS: In the present study, reusable Co0.5Ni0.5Fe2O4/SiO2/TiO2 composite matrix was incorporated with CdS NPs to develop an efficient photocatalyst, and antimicrobial agents for wastewater treatment, and disinfection purpose. The antibacterial performance of the gamma-irradiated samples was evaluated against various types of Gram-positive bacteria using ZOI, MIC, antibiofilm, and effect of UV-exposure. Antibacterial reaction mechanism was assessed by bacterial membrane leakage assay, and SEM imaging. In addition, their photocatalytic efficiency was tested against MB cationic dye as a typical water organic pollutant. RESULTS: Our results showed that, the formed CdS NPs were uniformly distributed onto the surface of the nanocomposite matrix. While, the resulted CdS-based nanocomposite possessed an average particle size of nearly 90.6 nm. The antibacterial performance of the prepared nanocomposite was significantly increased after activation with gamma and UV irradiations. The improved antibacterial performance was mainly due to the synergistic effect of both TiO2 and CdS NPs; whereas, the highest photocatalytic efficiency of MB removal was exhibited in alkaline media due to the electrostatic attraction between the cationic MB and the negatively-charged samples. In addition, the constructed heterojunction enabled better charge separation and increased the lifetime of the photogenerated charge carriers. CONCLUSION: Our results can pave the way towards the development of efficient photocatalysts for wastewater treatment and promising antibacterial agents for disinfection applications.

Antimicrobial and anti-aflatoxigenic activities of nanoemulsions based on Achillea millefolium and Crocus sativus flower extracts as green promising agents for food preservatives.

BACKGROUND: Although the mechanism of action of nanoemulsion is still unclear, the modern use of nanoemulsions made from natural extracts as antimicrobial and anti-aflatoxigenic agents represents a potential food preservation and a safety target. METHODS: Two natural nanoemulsion extracts of Crocus sativus (the saffron flower) and Achillea millefolium (the yarrow flower) were produced in the current study using a low-energy method that included carboxymethylcellulose and Arabic gum. The synthesized nanoemulsion was fully identified by different analytical methods. Detection of the volatile content was completed using GC-MS analysis. The antioxidant potential, and phenolic compounds content were analyzed in the extractions. The synthesized nanoemulsions were screened for their antimicrobial potential in addition to their anti-aflatoxigenic activity. RESULTS: The droplet size of Saffron flowers was finer (121.64 ± 2.18 nm) than yarrow flowers (151.21 ± 1.12 nm). The Zeta potential measurements of the yarrow flower (-16.31 ± 2.54 mV) and the saffron flower (-18.55 ± 2.31 mV) both showed high stability, along with low PDI values (0.34-0.41). The nanoemulsion of yarrow flower revealed 51 compounds using gas chromatography-mass spectrometry (GCMS), with hexanal (16.25%), ß-Pinene (7.41%), ß-Myrcene (5.24%), D-Limonene (5.58%) and Caryophyllene (4.38%) being the most prevalent. Additionally, 31 compounds were detected in the saffron nanoemulsion, with D-limonene (4.89%), isophorone (12.29%), 4-oxy isophorone (8.19%), and safranal (44.84%) being the most abundant. Compared to the nanoemulsion of the yarrow flower, the saffron nanoemulsion had good antibacterial and antifungal activity. Saffron nanoemulsion inhibited total fungal growth by 69.64-71.90% in a simulated liquid medium and demonstrated the most significant decrease in aflatoxin production. Infected strawberry fruits coated with nanoemulsion extracts exhibited high antimicrobial activity in the form of saffron flower and yarrow flower extract nanoemulsions, which inhibited and/or controlled the growth of Aspergillus fungi. Due to this inhibition, the lag phase was noticeably prolonged, the cell load decreased, and the stability time increased. CONCLUSION: This study will contribute to expanding the theoretical research and utilization of nanoemulsions as green protective agents in agricultural and food industries for a promising protection from the invasion of some pathogenic bacteria and fungi.

Contribution of different mechanisms to aminoglycoside resistance in clinical isolates of Acinetobacter baumannii.

The antibiotics overuse for infection treatment was the sparkle in the spreading of multi-drug resistance Acinetobacter baumannii in hospitals. In our study, we evaluated the contribution of the aminoglycoside resistance mechanisms of A. baumannii to the resistance surge in some selected Egyptian hospitals with a checkerboard assay application to retrieve the aminoglycoside activity. The resistance profile analysis of collected 200 A. baumannii isolates revealed a multidrug-resistant pattern with limited susceptibilities to aminoglycosides. Analysis of the prevalence of aminoglycoside-modifying enzyme (AMEs) genes revealed the presence of the six AMEs genes either singly or in combination in selected isolates and aph (3)-VIa gene was the predominant one. At the same time, four efflux pump genes of AdeABC and AdeKJL family showed significant (P < 0.001) up-regulation levels. Moreover, the implementation of combination strategy showed fourteen synergistic activities against two high-level aminoglycoside-resistance (HLAR) A. baumannii isolates. The findings highlighted the alarming levels of aminoglycoside resistance in A. baumannii isolates, which proved that a common enzymatic modification mechanism acts synergistically with decreased antibiotic accumulation in acquiring aminoglycoside resistance. Additionally, the study provides useful information for the promising synergistic combination therapy that reduces the therapeutic dose of aminoglycosides used and subsequently increases their clinical application.

Protective role of iron oxide nanocomposites on disease index, and biochemical resistance indicators against Fusarium oxysporum induced-cucumber wilt disease: In vitro, and in vivo studies.

Recently nanocomposites have become a super-growth inducers as well as vital antifungal agents, which enhance plant growth and suppress plant diseases. A new strategy regarding the fabrication of humic acid (H) and boron (B) conjugated Fe2O3 nanocomposites was performed. Fe2O3 NP-B and Fe2O3 NP-H were synthesized in the presence of gamma-rays (as a direct reducing agent). Gamma-rays provoked reduction of metal ions due to the liberated reducing electrons, (e-aq), in aqueous solutions which can be considered as a direct reduction. Antifungal potential against Fusarium oxysporum, the causative agent of wilt disease in cucumber was determined. Disease index percent, metabolic resistance indicators in cucumber plant as response to promotion of systemic resistance (SR) were recorded. Results illustrated that both Fe2O3 NPs-B and Fe2O3 NPs-H nanocomposites had antifungal activity against F. oxysporumin vitro as well as in vivo. Results revealed that minimum inhibitory concentrations of Fe2O3 NPs-B and Fe2O3 NPs-H nanocomposites were 0.25 and 0.125 mM, respectively. Application of Fe2O3 NPs-B (0.25 mM) and Fe2O3 NPs-H (0.125 mM) appeared highly reduced the cucumber wilt disease symptoms incidence caused by F. oxysporum, and recorded disease severity by 83.33%. Fe2O3 NPs-B was the best treatment reducing disease indexes by 20.83% and gave highly protection against wilt disease by 75.0% and came next Fe2O3 NPs-H which reduced disease indexes by 25% and gave 69.99% protection against disease. Fe2O3 NPs-B and Fe2O3 NPs-H treatments improved morphological traits, photosynthetic pigments, osmolytes, total phenol and antioxidant enzymes activities in both infected and non-infected plants. The beneficial effects of the synthesized Fe2O3 NPs-B and Fe2O3 NPs-H nanocomposites were extended to increase not only the total phenol, and total soluble protein contents but also the activities of peroxidase (POD), and polyphenol oxidase (PPO) enzymes of the healthy and infected cucumber plants in comparison with control.

Promising antimicrobial and antibiofilm activities of Orobanche aegyptiaca extract-mediated bimetallic silver-selenium nanoparticles synthesis: Effect of UV-exposure, bacterial membrane leakage reaction mechanism, and kinetic study.

In this research, Orobanche aegyptiaca extract was utilized as an eco-friendly, and cost-effective green route for the construction of bimetallic silver-selenium nanoparticles (Ag-Se NPs). Bimetallic Ag-Se NPs were characterized by XRD, EDX, FTIR, HR-TEM, DLS, SEM/mapping and EDX studies. Antimicrobial, and antibiofilm potentials were tested against some selected pathogenic bacteria and unicellular fungi by ZOI, MIC, effect of UV exposure, and inhibition %. Reaction mechanism was assessed through membrane leakage assay and SEM imaging. HRTEM analysis confirmed the spherical nature and was ranged from 18.1 nm to 72.0 nm, and the avarage particle size is determined to be 30.58 nm. SEM imaging prove that bimetallic Ag-Se NPs presents as a bright particles, and both Ag and Se were distributed equally across O. aegyptiaca extract and Guar gum stabilizers. ZOI results showed that, bimetallic Ag-Se NPs have antimicrobial activity against S. aureus (20.0 nm), E. coli (18.5 nm), P. aeruginosa (12.6 nm), and C. albicans (18.2 nm). In addition, bimetallic Ag-Se NPs were able to inhibit the biofilm formation for S. aureus by 79.48%, for E. coli by 78.79%, for P. aeruginosa by 77.50%, and for C. albicans by 73.73%. Bimetallic Ag-Se NPs are an excellent disinfectant once it had excited by UV light. It was observed that the quantity of cellular protein discharged from S. aureus is directly proportional to the concentration of bimetallic Ag-Se NPs and found to be 244.21 µg/mL after the treatment with 1 mg/mL, which proves the antibacterial characteristics, and explains the creation of holes in the cell membrane of S. aureus producing in the oozing out of the proteins from the S. aureus cytoplasm. Based on the promising properties, they showed superior antimicrobial potential at low concentration (to avoid toxicity) and continued-phase durability, they may use in pharmaceutical and biomedical applications.

Gallic acid and/or cerium oxide nanoparticles synthesized by gamma-irradiation protect cisplatin-induced nephrotoxicity via modulating oxidative stress, inflammation and apoptosis.

Cisplatin is one of the most significant anticancer. However, its use is associated with numerous toxicities especially nephrotoxicity. The main aim of this work was to examine the protective effect of Gallic acid (GA) and/or cerium oxide nanoparticles (CONPs) synthesized by gamma-irradiation on cisplatin-induced nephrotoxicity in rats. To do that, 48 adult male albino rats were separated into eight groups and received GA (100 mg/kg orally) and/or CONPs (15 mg/kg i. p.) for 10 days before injection with a single dose of cisplatin (7.5 mg/kg i. p.). The findings showed that cisplatin treatment impaired kidney functioning as shown by elevated serum levels of urea and creatinine. Additionally, the oxidative stress indicators (MDA and NO), levels of NF-kB, pro-inflammatory cytokines (IL1-and TNF-) and pro-apoptotic proteins (BAX and caspase-3) were raised after cisplatin injection, while levels of intrinsic anti-oxidants (CAT, SOD, and GSH) and anti-apoptotic protein (Bcl-2) were reduced. Moreover, renal toxicity was confirmed by alteration in normal histological architecture of the kidneys. On the other hand, pretreatment with CONPs and/or GA ameliorated cisplatin-induced nephrotoxicity as evidenced by improvement of renal function parameters and levels of oxidative stress, inflammatory and apoptotic markers in renal tissue along with the renal histopathological changes. This study clarifies how GA and CONPs protect against cisplatin-induced nephrotoxicity and demonstrates any potential synergism between them. Therefore, they can be considered as promising nephroprotective agents during chemotherapy.

Ziziphus spina-christi extract-stabilized novel silver nanoparticle synthesis for combating Fusarium oxysporum-causing pepper wilt disease: in vitro and in vivo studies.

The novelty of the present study is studying the ability of aqueous Ziziphus spina-christi leaves' extract (ZSCE) to produce eco-friendly and cost-effective silver nanoparticles (Ag NPs) against Fusarium wilt disease. Phytochemical screening of ZSCE by HPLC showed that they contain important antimicrobial substances such as Rutin, Naringin, Myricetin, Quercetin, Kaempferol, Hesperidin, Syringeic, Eugenol, Pyrogallol, Gallic and Ferulic. Characterization methods reveal a stable Ag NPs with a crystalline structure, spherical in shape with average particle size about 11.25 nm. ZSCE and Ag NPs showed antifungal potential against F. oxysporum at different concentrations with MIC of Ag NPs as 0.125 mM. Ag NPs treatment was the most effective, as it gave the least disease severity (20.8%) and the highest protection rate (75%). The application of ZSCE or Ag NPs showed a clear recovery, and its effectiveness was not limited for improving growth and metabolic characteristics only, but also inducing substances responsible for defense against pathogens and activating plant immunity (such as increasing phenols and strong expression of peroxidase and polyphenol oxidase as well as isozymes). Owing to beneficial properties such as antifungal activity, and the eco-friendly approach of cost and safety, they can be applied in agricultural field as novel therapeutic nutrients.

Synthesis, Antimicrobial, and Antibiofilm Activities of Some Novel 7-Methoxyquinoline Derivatives Bearing Sulfonamide Moiety against Urinary Tract Infection-Causing Pathogenic Microbes.

A new series of 4-((7-methoxyquinolin-4-yl) amino)-N-(substituted) benzenesulfonamide 3(a-s) was synthesized via the reaction of 4-chloro-7-methoxyquinoline 1 with various sulfa drugs. The structural elucidation was verified based on spectroscopic data analysis. All the target compounds were screened for their antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria, and unicellular fungi. The results revealed that compound 3l has the highest effect on most tested bacterial and unicellular fungal strains. The highest effect of compound 3l was observed against E. coli and C. albicans with MIC = 7.812 and 31.125 µg/mL, respectively. Compounds 3c and 3d showed broad-spectrum antimicrobial activity, but the activity was lower than that of 3l. The antibiofilm activity of compound 3l was measured against different pathogenic microbes isolated from the urinary tract. Compound 3l could achieve biofilm extension at its adhesion strength. After adding 10.0 µg/mL of compound 3l, the highest percentage was 94.60% for E. coli, 91.74% for P. aeruginosa, and 98.03% for C. neoformans. Moreover, in the protein leakage assay, the quantity of cellular protein discharged from E. coli was 180.25 µg/mL after treatment with 1.0 mg/mL of compound 3l, which explains the creation of holes in the cell membrane of E. coli and proves compound 3l's antibacterial and antibiofilm properties. Additionally, in silico ADME prediction analyses of compounds 3c, 3d, and 3l revealed promising results, indicating the presence of drug-like properties.

Antimicrobial Potency and E. coli ß-Carbonic Anhydrase Inhibition Efficacy of Phenazone-Based Molecules.

In this investigation, 4-antipyrinecarboxaldhyde was reacted with methyl hydrazinecarbodithioate to afford the carbodithioate derivative 3. The as-prepared carbodithioate derivative 3 is considered to be a key molecule for the preparation of new antipyrine-1,3,4-thiadiazole-based molecules (4-9) through its reaction with the appropriate hydrazonoyl halides. Furthermore, a typical Biginelli three-component cyclocondensation reaction involving ethyl acetoacetate, 4-antipyrinecarboxaldhyde, and thiourea under the standard conditions is carried out in the presence of sulfuric acid to afford the corresponding antipyrine-pyrimidine hybrid molecule (10). The latter was submitted to react with hydrazine monohydrate to provide the corresponding hydrazide derivative (11) which, under reaction with ethyl acetoacetate in refluxing ethanol containing catalytic amount of acetic acid, afforded the corresponding derivative (12). The structure of the newly synthesized compounds was affirmed by their spectral and microanalytical data. We also screened for their antimicrobial potential (ZOI and MIC) and conducted a kinetic study. Additionally, the mechanism of biological action was assessed by a membrane leakage assay and SEM imaging technique. Moreover, the biological activities and the binding modes of these compounds were further supplemented by an in silico docking study against E. coli ß-carbonic anhydrase. The amount of cellular protein released by E. coli is directly correlated to the concentration of compound 9, which was found to be 177.99 µg/mL following treatment with 1.0 mg/mL of compound 9. This finding supports compound 9's antibacterial properties and explains how the formation of holes in the E. coli cell membrane results in the release of proteins from the cytoplasm. The newly synthesized compounds represent acceptable antimicrobial activities with potential action against E. coli ß-carbonic anhydrase. The docking studies and antimicrobial activity test proved that compound (9) declared a greater activity than the other synthesized compounds.

Silver nanoparticles coated medical fiber synthesized by surface engineering with bio-inspired mussel powered polydopamine: An investigated antimicrobial potential with bacterial membrane leakage reaction mechanism.

Nature frequently provides narrative biological motivation. This study reports on oxygen-induced auto-polymerization of dopamine on the surface of medical cotton fibers to develop super-hydrophobic surfaces. The versatile reactivity of polydopamine (PDA) surfactant was adopted to deposit silver nanoparticles (Ag NPs) on the surface of medical cotton. SEM micrographs demonstrated the uniform deposition of Ag NPs. The antimicrobial reactivity confirmed the potential of Ag-loaded PDA-cotton fiber to hinder the growth of some tested pathogenic microbes. Silver-loaded PDA-cotton fibers showed the most promising zone of inhibition (ZOI) against (33.5 mm), Candida tropicalis (30.2 mm), and Aspergillus niger (30.2 mm). In growth curve assay, after addition of silver-loaded PDA-cotton fibers, the O.D. were lower (0.365 nm), showing the repression impact on S. aureus. It was observed that the quantity of cellular protein discharged from S. aureus is directly proportional to the concentration of silver-loaded PDA-cotton fibers and found to be 159.68 µg/ml after the treatment with silver-loaded PDA-cotton fibers (2 cm × 2 cm), which proves the antibacterial characteristics of the synthesied silver-loaded PDA-cotton fibers. The obtained antimicrobial results gives solution in treating pathogenic microbes and the application of silver-loaded PDA-cotton fibers as wound dressing in biomedical and pharmaceutical fields.