Gram-positive Research Articles

Surveillance of Antimicrobial Resistance Bacteria in a Healthcare Facility at an Industrial Site in Saudi Arabia.

This study aimed to perform surveillance and identify antimicrobial resistance (AMR) in the most common pathogenic bacteria in a healthcare facility in Rabigh City, Saudi Arabia. A total of 1,933 samples were processed from patients during the study period from January 2022 to June 2022. Identification and antimicrobial susceptibility of the cultured isolates were performed using the MicroScan system. Out of the 1,933 tested samples, 11.1% (n = 214) were positive for bacterial growth. A relatively higher percentage of isolates was recovered from patients older than 50 years (55.9%). Gram-negative bacteria (67.3%) were significantly more prevalent than Gram-positive bacteria (32.7%). The Gram-negative pathogenic bacteria comprised mainly Escherichia coli and Klebsiella pneumoniae, followed by Pseudomonas aeruginosa. Staphylococ-cus epidermidis and coagulase-negative staphylococci were found at relatively high abundance in Gram-positive bacteria. Increased resistance to carbapenem antibiotics was observed in K. pneumoniae. In Gram-positive bac¬teria, > 50% of the isolates of S. epidermidis were resistant to 13 tested antimicrobial agents. This study provided an overview of the distribution of pathogenic bacteria and antimicrobial susceptibility of the prevalent Gram-negative and Gram-positive pathogenic bacteria in a major healthcare facility in Saudi Arabia. It highlights the importance of continuously monitoring AMR bacteria in healthcare settings to ensure the effective use of antibiotics for treatment.

Novel Pleuromutilin Derivatives Conjugated with Phenyl-sulfide and Boron-containing Moieties as Potent Antibacterial Agents against Antibiotic-resistant Bacteria

In response to the escalating threat of microbial resistance, a series of novel pleuromutilin derivatives, conjugated with phenyl-sulfide and boron-containing moieties, were designed and synthesized. Most derivatives, especially 14b and 16b, demonstrated significant efficacy against Gram-positive bacteria, including multidrug-resistant strains, as well as pleuromutilin-resistant strains. Compound 16b showed high stability in the liver microsomes of rats and humans, along with acceptable tolerance in vitro and in vivo. Additionally, compound 16b exhibited promising efficacy in MRSA-infected mouse models. Our data highlight the potential of conjugated pleuromutilin derivatives as valuable agents against drug-resistant bacteria.

Eco-Friendly Synthesis of Silver Nanoparticles: Enhancing Optimization Reaction, Characterization, and Antimicrobial Properties with Lantana camara from Geothermal Area

Green synthesis methods for producing silver nanoparticles (AgNPs) have garnered significant attention for their potential in medical applications. Despite the known potential of Lantana camara in AgNP synthesis, there is a lack of studies investigating its application when grown in extreme geothermal environments, which may influence the properties and efficacy of the synthesized nanoparticles. This research aimed to fabricate AgNPs utilizing aqueous extract from Lantana camara, a plant growing in an extreme geothermal manifestation area. Another aim of this study is to evaluate their antimicrobial activity. Qualitative and quantitative phytochemical analyses of the plant's leaves were also conducted. Reaction optimization was performed using response surface methodology (RSM), employing a central composite design (CCD) approach. The characterization of AgNPs involved UV-Vis spectroscopy, FTIR, SEM-EDX, and PSA. The antimicrobial testing was conducted against Gram-positive bacterium (S. aureus), Gram-negative bacterium (E. coli), and the fungus (C. albicans). The phytochemicals analysis revealed that the L. camara leaf extract contains flavonoids, phenolics, saponins, tannins, and steroids, lacking alkaloids and terpenoids, with total phenolic and flavonoid contents of 11.94 mg (GAE/g) and 6.70 mg (QE/g), respectively. The AgNPs exhibited a spherical shape with a surface plasmon resonance (SPR) peak at a wavelength of 417 nm, and the smallest particle size measured was 44 nm. Based on FTIR analysis, AgNPs have functional groups such as OH, NH, C=C, and CH that were identified as groups involved in the reduction of Ag+ to Ag0 during the green synthesis of AgNPs. The AgNPs demonstrated the lowest antifungal activity against C. albicans. In summary, the aqueous leaf extract of L. camara from geothermal manifestation areas can serve as a bioreductant for AgNPs, exhibiting higher antibacterial activity against Gram-positive bacteria compared to Gram-negative ones.

Proactive Monitoring of Changes in the Microbial Community Structure in Wastewater Treatment Bioreactors using Phospholipid Fatty Acid Analysis

Diverse microbial community structures (MCS) in wastewater treatment plants (WWTPs) are vital for effectively removing nutrients and chemicals from wastewater. However, the regular monitoring of MCS in WWTP bioreactors remains unattractive owing to the skill and cost required for deploying modern microbial molecular techniques in the routine assessment of engineered systems. In contrast, low-resolution methods for assessing broad changes in the MCS, such as phospholipid fatty acid (PLFA) analysis, have been used effectively in soil studies for decades. Despite using PLFA analysis in soil remediation studies to capture the long-term effects of environmental changes on MCS, its application in WWTPs, where the microbial mass is dynamic and operational conditions are more fluid, remains limited. In this study, microbial communities in a controlled pilot plant and 12 full-scale activated sludge plants (ASPs) were surveyed over a two-year period using PLFA analysis. This study revealed that changes in the MCS in wastewater bioreactors could be detected using PLFA analysis. The MCS comprised 59% Gram-negative and 9% Gram-positive bacteria, 31% fungi, and 1% actinomycetes. The abundances of Gram-negative bacteria and fungi were strongly inversely correlated, with an R2 = 0.93, while the fatty acids cy17:0 and 16:1ω7c positively correlated (R2 = 0.869). Variations in temperature, solid retention time, and WWTP configuration significantly influenced the MCS in activated sludge reactors. This study showed that WWTP bioreactors can be routinely monitored using PLFA analysis, and changes in the bioreactor profile that may indicate imminent bioreactor failure can be identified.

Formulation and Optimization of Solid Lipid Nanoparticle-based Gel for Dermal Delivery of Linezolid Using Taguchi Design.

Linezolid (LNZ) is a synthetic oxazolidinone antibiotic approved for the treatment of uncomplicated and complicated skin and soft tissue infections caused by gram-positive bacteria. Typically, LNZ is administered orally or intravenously in most cases. However, prolonged therapy is associated with various side effects and life threatening complications. Cutaneous application of LNZ will assist in reducing the dose, hence minimizing the unwanted side/adverse effects associated with oral administration. Dermal delivery provides an alternative route of administration, facilitating a local and sustained concentration of the antimicrobial at the site of infection. The current research work aimed to formulate solid lipid nanoparticles (SLNs) based gel for dermal delivery of LNZ in the management of uncomplicated skin and soft tissue infections to maximise its benefits and minimise the side effects. SLNs were prepared by high-shear homogenisation and ultrasound method using Dynasan 114 as solid lipid and Pluronic F-68 as surfactant. The effect of surfactant concentration, drug-to-lipid ratio, and sonication time was investigated on particle size, zeta potential, and entrapment efficiency using the Taguchi design. The main effect plot of means and signal-to-noise ratio were generated to determine the optimized formulation. The optimized batch was formulated into a gel, and ex-vivo permeation study, in-vitro and in-vivo antibacterial activity were conducted. The optimised process parameters to achieve results were 2% surfactant concentration, a drug-to-lipid ratio of 1:2, and 360 s of sonication time. The optimized batch was 206.3± 0.17nm in size with a surface charge of -24.4± 4.67mV and entrapment efficiency of 80.90 ± 0.45%. SLN-based gel demonstrated anomalous transport with an 85.43% in vitro drug release. The gel showed a 5 cm zone of inhibition while evaluated for in vitro antibacterial activity against Staphylococcus aureus. Ex-vivo skin permeation studies demonstrated 20.308% drug permeation and 54.96% cutaneous deposition. In-vivo results showed a significant reduction in colony-forming units in the group treated with LNZ SLN-based gel. Ex-vivo studies ascertain the presence of the drug at the desired site and improve therapy. In-vivo results demonstrated the ability of SLN-based gel to significantly reduce the number of bacteria in the stripped infection model. The utilization of SLN as an LNZ carrier holds significant promise in dermal delivery.

Evaluation of titanium dioxide/catechol polyurethane composite for antimicrobial resistance and wastewater treatment

In this study, a novel approach for the environmentally conscious extraction of titanium dioxide from ilmenite ore while limiting the environmental impact and enhancing the advantage from an economic process. Leaching conditions were tested with different acids for effective separation of the TiO2 and were optimized concerning different experimental parameters. TiO2 and TiO2NPs were characterized using with different tools. Catechol polyurethane foam immobilized with TiO2NPs was prepared and its antimicrobial action was tested against Gram-negative bacterium E. coli, Gram-positive bacterium B. cereus, and fungus A. niger. CAT-PUF /TiO2NPs showed antimicrobial effect against E. coli, B. cereus, and A. niger with inhibition zones of 27 ± 0.14, 12 ± 0.14, and 22 ± 0.06 mm, respectively. Incorporating bioinformatics, this research contributes to the burgeoning field of nanotechnology-enabled antimicrobial materials, offering insights into the potential applications of CAT-PUF/TiO2NPs in combating microbial threats. Through bio-informatics tools, the potential toxicity of the synthesized nanoparticles was assessed, providing valuable insights into their safety profile and environmental impact. Furthermore, simulating the binding affinity between the nanoparticles and target biomolecules, such as cell membrane proteins or enzyme receptors, this aspect of the research sheds light on the mechanistic underpinnings of their antimicrobial efficacy.

Biocompatible Pickering emulsions and films: Unlocking the chitosan-polyvinyl alcohol synergy for multifaceted capabilities

The exciting potential of harnessing the synergy between polysaccharides and bioactive components is attracting significant scientific interest. This research paves the way for the development of novel materials that can improve human health. Therefore, current research is conducted to explore the innovative use of chitosan, polyvinyl alcohol (PVA) complex (CHN-PVA), olive oil-stabilized Pickering emulsions (PEs), and films with multifaceted applications. The sonication stabilized Pickering emulsions (PEs at different pH values 3, 5, 7, 9, and 11) exhibited decrease in particle size compared to control PEs. The pH significantly impacted the zeta potential of PEs. Fourier-transform infrared spectroscopy (FTIR) confirmed the non-covalent linkages. The antibacterial activity of the PEs revealed greater efficacy against gram-positive bacteria than gram-negative bacteria. The CHN-PVA synergy greatly impacted the mechanical properties of films, resulting in tremendous increase of tensile strength and elongation at break compared to CHN film. The PEs efficiently delivered quercetin at neutral pH. The electro spraying of PEs significantly extended strawberry shelf life. Finally, the films exhibited promising properties of adsorbent and the results depicted that pH had a significant impact on methylene blue removal. Conclusively, this investigation underscores the potential of CHN-PVA films in food, health, and environmental fields.

Impact of Dual-coated Silver Nanoparticle and Antibiotic Sutures on Wound Healing in Inflammatory Mouse Models

ABSTRACT Background: The use of silver nanoparticles (AgNPs) in biomedicine has emerged in a big way owing to its antibacterial and anti-inflammatory properties. We hypothesize that combining the AgNPs with antibiotics for coating sutures will enhance the antibacterial property of sutures with the added advantage of the immunomodulatory effect of AgNPs on tissue healing. Materials and Methods: Polyglactin sutures were coated with AgNPs using the dip-coating method. The uniform coating and morphology of AgNPs on the suture surface were confirmed using scanning electron microscopy (SEM). Each type of suture – polyglactin plain, antibiotic coated (Triclosan), AgNP coated, and dually coated (antibiotic and AgNP) – was assessed for their antibacterial properties against Gram-positive bacteria, Gram-negative bacteria, and anaerobes. These sutures were utilized in an abdominal and systemic inflammatory mice model for ileal anastomosis. The intestinal tissue was evaluated for acute and chronic inflammation and collagen deposition to assess the healing and inflammatory response. Results: The SEM and energy dispersive X-ray analysis showed successful coating of AgNPs on plain and antibiotic-coated sutures. In comparison with the other groups, the dually coated suture had the best in vitro antibacterial efficacy. The AgNP-coated sutures were able to decrease both acute and chronic inflammatory cell infiltration, but the collagen synthesis and deposition were enhanced. Conclusion: AgNPs can be coated on Polyglactin suture either alone or in combination with antibiotics with preserved antibacterial effects. The dual coating of sutures gives a synergistic antibacterial effect. The AgNP diminishes immune response in the presence of preserved extracellular matrix generation.

Evaluation of Biological Potential of Red Onion Skin Extract for Anticancer and Antimicrobial Activities

Chemotherapy, while effective in combating cancer, frequently induces severe adverse effects and lacks specificity. This investigation aims to assess the potential of red onion skin, a byproduct abundant in polyphenols and flavonoids, as a reservoir of natural compounds possessing anticancer and antimicrobial properties. Two extracts, specifically ethanolic red onion skin (EROS) extract, and chromatographic red onion skin (CROS) extract were subjected to comprehensive biological analysis. Gas chromatography-mass spectrometry (GC-MS) and infrared (IR) spectroscopy revealed that the CROS extract predominantly encompasses dihydroxy benzoic acid (DHBA) and its derivatives, alongside fatty acids recognized for enhancing DHBA penetration into cellular membranes. The antimicrobial activity of the extracts was systematically evaluated against Gram-positive bacteria, Gram-negative bacteria, and yeast using the agar well diffusion method, the minimum inhibition concentration (MIC), and the minimum microbicidal concentration (MMC) tests. The results unequivocally demonstrated that the CROS extract exhibited markedly superior antibacterial efficacy against E. coli, B. cereus, and C. albicans at concentrations of 50, 60, and 70µg/ml, respectively. Moreover, mice administered with CROS extract enhanced biochemical profiles, including superoxide dismutase (SOD) levels, and improved liver histology compared to those treated with the whole extract. These discerning findings propose that CROS extract harbors substantial promise as a natural and innocuous therapeutic intervention for cancer and microbial infections. Nevertheless, further more research is imperative to support these findings and unravel the intricate mechanisms of its action.

Determining conditions for inactivation of multispecies biofilm cells by peracetic acid applying response surface methodology

Biofilms can form on various surfaces and are typically associated with multiple microbial species. Particularly in the food industry, biofilms are often a source of contamination, necessitating mitigation strategies. In this study, Response Surface Methodology (RSM) was utilized to optimize conditions for the inactivation of multispecies biofilm cells, with peracetic acid (PAA) (0.05% to 0.5%), treatment time (5 to 30 minutes), and temperature (25 to 60 ºC) as independent variables. The multispecies biofilm consisted of Gram-positive and Gram-negative bacteria previously isolated from biofilms formed in the presence of raw milk. Stainless steel (SS) coupons were immersed in reconstituted whole milk inoculated with Pseudomonas fluorescens, Rahnella inusitata, Staphylococcus aureus, and Micrococcus aloeverae. Sessile cell counts of approximately 108 CFU/cm2 were obtained after 10 days of incubation at 4 ºC. The response surface model exhibited a good fit, with R2 of 0.949 and adjR2 of 0.883. All independent variables had a positive effect on the inactivation of biofilm cells. The maximum inactivation achieved was approximately 7 log (CFU/cm2), with the highest values observed at 0.5% PAA, for 30 min at 60°C. Epifluorescence microscopy revealed that many cells in the biofilm were dead or injured after treatment at the central point (PAA = 0.275%; Time = 17.5 min; Temperature = 42.5 ºC). RSM helps to predict better conditions for maximum biofilm eradication and proves to be a promising approach for monitoring the inactivation of multispecies biofilm cells, which warrants further exploration.

Rubia-Inspired biogenic Synthesis of Cu-ZnO Nanocomposites: Dual-modelling of visible light Photocatalytic Degradation and Antibacterial Assessment

Cu-doped ZnO nanoparticles (NPs) were synthesised using Rubia cordifolia root extract and their photocatalytic degradation and antimicrobial properties were evaluated. Among all dopant concentrations, UV-VIS analysis of 5% Cu-ZnO NPs revealed a clean shift towards the visible range with a reduction in the band gap from 3.2 eV for pristine ZnO to 2.98 eV. Formed NPs were identified as wurtzite crystal structure (size of 16.67 nm) having a functional group of ZnO, using XRD and FTIR analysis. Highest photocatalytic degradation efficiencies of both Alizarine Red (AZ) (80%) and Rhodamine B (RhB) (82%) dyes were by 5% Cu-ZnO NPs. Statistical modelling and optimization were conducted using Response Surface Methodology (RSM) and Adaptive Neuro-Fuzzy Inference System (ANFIS), resulting in development of models having >90% predictive accuracy. Furthermore, the biogenic Cu-ZnO nanoparticles exhibits effective antimicrobial properties against both gram-positive (S. aureus) and gram-negative (E. coli) bacteria. The biogenic synthesis approach demonstrated enhanced photocatalytic efficiency and antimicrobial properties, suggesting its potential for environmentally friendly applications.

Synthesis and characterization of CeO2 nanoparticles using Plectranthus barbatus leaf extract and its CO gas sensing and antimicrobial activity

In this study, we synthesized cerium oxide nanoparticles (CeO2 NPs) using Plectranthus barbatus leaf extract. Characterization via X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and UV–visible spectroscopy revealed a bandgap of 2.98 eV. XRD confirmed their crystalline nature, while HRTEM showed cubic fluorite structures with an average particle size of 11.23 nm. The CeO2 NPs exhibited antibacterial properties against both gram-positive and gram-negative bacteria and high sensitivity to carbon monoxide (CO) at 100 °C, especially at low concentrations. This research highlights the low environmental impact and potential applications of CeO2 NPs in gas sensing and antibacterial contexts.

Unveiling the potent Antimicrobial Photodynamic Therapy in Gram-positive and Gram-negative bacteria – Water remediation with monocharged chlorins

Water pollution is a significant concern worldwide, and it includes contaminants such as antibiotic-resistant pathogens. Antimicrobial photodynamic therapy (aPDT) offers a non-invasive and non-toxic alternative for the inactivation of these microorganisms. So, this study reports the synthesis, structural characterisation, photophysical properties, and aPDT efficacy of cationic free-base and zinc(II) chlorin (Chl) derivatives bearing N,N-dimethylpyrrolydinium groups (H2Chl 1a and ZnChl 1b). The aPDT assays were performed against two bacterial models: Staphylococcus aureus (Gram-(+)) and Escherichia coli (Gram-(–)). The H2Chl 1a and ZnChl 1b distinct’s solubility profile, coupled with their ability to generate singlet oxygen (1O2) under light exposure, (H2Chl 1a, ФΔ = 0.58 <TPP, ФΔ = 0.65 < ZnChl 1b, ФΔ = 0.83) opens up their potential application as photosensitizers (PS) in aPDT. The effectiveness of H2Chl 1a and ZnChl 1b at 1.0 and 5.0 μM in aPDT against S. aureus and E. coli at 500 W.m–2 (total exposure time: 60 –120 min) showed a viability reduction > 6.0 log10 CFU.mL–1. Additionally, KI was used as a coadjuvant to potentiate the photoinactivation of E. coli, reaching the method’s detection limit (> 4.0 log10 RLU). As most of the PS developed to inactivate Gram-negative bacteria are cationic with three or more charges, the fact that the H2Chl 1a and ZnChl 1b with only one cationic charge photoinactivate E. coli at low concentrations and with a reduced light dose, it is an importing discovery that deserves further exploration. These monocharged chlorin dyes have the potential for water remediation.

Signal “on-off” photoelectrochemical biosensor for gram-positive bacteria quick detection based on vancomycin functionalized BiVO4/Au photoelectrode

Signal “on-off” photoelectrochemical biosensor for gram-positive bacteria quick detection based on vancomycin functionalized BiVO4/Au photoelectrode

A newly identified secretory phospholipase A2 group XIIA homolog (LcPLA2XIIA) in Larimichthys crocea exhibits antimicrobial and antitumor activities

The phospholipase A2 (PLA2) superfamily has attracted increasing attention in recent years due to the multiple physiological and pathological functions exerted by its members. Up to date, the knowledge about the biological role of PLA2XIIA subfamily members remains limited. In this study, a new member of PLA2XIIA subfamily, LcPLA2XIIA, was characterized in large yellow croaker. Different from most members of the PLA2 superfamily with positive charge, LcPLA2XIIA encodes an anionic protein, which is similar to other members of PLA2XIIA subfamily. LcPLA2XIIA is highly expressed in the intestine, and afterwards, it is up-regulated after with Pseudomonas plecoglossicida or Staphylococcus aureus. LcPLA2XIIA exhibits strong inhibitory activity against these two bacteria. The results indicate that LcPLA2XIIA plays an important role in the antimicrobial immune responses of large yellow croaker. LcPLA2XIIA displays strong binding activity to all the tested bacteria. It specifically interacts with LTA, a unique component on the surface of Gram-positive bacteria. It also significantly promotes bacterial agglutination in the presence of Ca2+. These findings reveal that the binding and agglutinating abilities of LcPLA2XIIA to bacteria contribute greatly to its antibacterial activity. In addition, LcPLA2XIIA significantly inhibits the proliferation of infectious hematopoietic necrosis virus instead of recombinant human adenovirus type 5. It also suppresses the growth of human colorectal adenocarcinoma cells by inducing apoptosis, but it has no obvious inhibitory effect on the growth of epithelioma papulosum cyprinid cells. This study provides new insights into the antibacterial activity, and the mechanism of LcPLA2XIIA in large yellow croaker, and antiviral and antitumor functions of PLA2XIIA subfamily members.

Zn(II) enhances the antimicrobial effect of chloroxine and structural analogues against drug-resistant ESKAPE pathogens in vitro

The emerging antibiotic-resistant bacteria, especially the “ESKAPE” pathogens, pose a continuous threat to global health. In this study, we explored metalloantibiotics as promising therapeutics and innovative antimicrobial agents. The role of metal in the antimicrobial activity of chloroxine (5,7-dichloro-8-hydroxyquinoline), as a metalloantibiotic, was investigated by minimal inhibit concentration (MIC) assay and a series of assays, including growth curve, time-killing, and UV–visible spectroscopy and PAR (4-(2-pyridylazo)-resorcinol) competition assays. Both chloroxine and its structural analogues exhibited increased antibacterial potency against Gram-positive bacteria compared to Gram-negative bacteria. The introduction of exogenous manganese or zinc ions significantly boosted chloroxine’s antibacterial efficacy against Gram-negative bacteria, including the notorious ESKAPE pathogens. However, the enhanced antibacterial activity induced by zinc ions could be negated in the presence of copper or ferrous iron ions, as well as changes in oxygen availability, highlighting the involvement of proton motive force, oxidative and antioxidative systems. Notably, chloroxine effectively inhibited the enzymatic activity of superoxide dismutase (SOD). In addition, chloroxine could reverse polymyxin and carbapenem resistance in E. coli in vitro. Therefore, these results suggested that chloroxine with zinc ions are promising therapeutics and antibiotics potentiator to combat multidrug-resistant ESKAPE pathogens

A Study of the Bioactive Compounds, Antioxidant Capabilities, Antibacterial Effectiveness, and Cytotoxic Effects on Breast Cancer Cell Lines Using an Ethanolic Extract from the Aerial Parts of the Indigenous Plant Anabasis aretioïdes Coss. &amp; Moq.

Anabasis aretioïdes contain numerous bioactive compounds that provide several advantages, including antioxidant, antibacterial, anticancer, neuroprotective, anti-inflammatory, and antidiabetic characteristics. This study aimed to make a hydroethanolic extract from the aerial part of the plant, analyze its biochemical compounds, and test its biological activities. From HPLC-DAD analysis, cinnamic acid, sinapic acid, and vanillin bioactives were found to be the main compounds in the extract. The spectrometric tests revealed that the extract was rich in flavonoids (8.52 ± 0.32 mg RE/100 g DW), polyphenols (159.32 ± 0.63 mg GAE/100 g DW), and condensed tannins (8.73 ± 0.23 mg CE/100 g DW). The extract showed significant antioxidant activity. There were strong correlations between the amount of flavonoid or polyphenol and the antioxidant assays, including ABTS, DPPH, β-carotene, and TAC. The extract also showed highly effective results against Gram-positive bacteria Staphylococcus aureus and Enterococcus faecalis as well as against Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, and showed promising cytotoxicity against breast cancer cell lines MCF-7 and MDA-MB-231. The in silico modeling of the bioactive compounds contained in the extract illustrated their interaction mode with the active sites of particular target proteins, and it showed that rutin had the strongest effect on stopping NADPH oxidase enzyme, with a glide score of −6.889 Kcal/mol. Sinapic acid inhibited E. coli beta-ketoacyl-[acyl carrier protein] synthase (−7.517 kcal/mol), and apigenin showed high binding affinity to S. aureus nucleoside di-phosphate kinase, with −8.656 kcal/mol. Succinic acid has the strongest anticancer effect for caspase-3, with a glide score of −8.102 kcal/mol. These bioactive components may be beneficial as antioxidant and antibacterial applications in medicine, foods, natural cosmetics, and breast cancer prevention in the future. As a result, the use of this indigenous plant must be considered to maximize its value and preservation.

Novel structural determinants and bacterial death-related regulatory effects of the scorpion defensin BmKDfsin4 against gram-positive bacteria

Numerous defensins constitute a family of cationic antimicrobial peptides with high degrees of sequence variability, and in-depth characterization of their structural basis and antibacterial mechanisms remains limited. Here, a representative scorpion defensin, BmKDfsin4, with two distinct hydrophobic and basic residue clusters, was extensively investigated. The hydrophobic residue cluster, formed by Phe2, Pro5, Phe6, Phe28 and Leu29 residues, strongly influences the antibacterial activity of BmKDfsin4 against Gram-positive bacteria. Compared with the three scattered Lys13, Lys30 and Arg32 residues, the basic residue cluster, consisting of the Arg19, Arg20, Arg21 and Arg37 residues, played a less important role. The synergistic interaction between the basic residue cluster and Arg32 significantly affected BmKDfsin4 function. The bacterial growth inhibition by BmKDfsin4 was associated with regulating expression levels of cell division-related genes, cell wall synthesis-related genes and bacterial autolysis-related genes rather than destroying the bacterial cell membrane. The coincubation of BmKDfsin4 with the bacterial strains induced gradual changes in the bacterial surface from a rough and thin surface to a noticeably wrinkled surface together with abundant white spots and even complete cavities within the bacteria. These findings revealed novel structural determinants and bacterial death-related regulatory effects of the defensin BmKDfsin4 and highlighted diverse antibacterial mechanisms of defensins.

Bacterial Co-Infections and Antibiotic Resistance in Urinary Tract Infection of Covid-19 Patients in Erbil City

The COVID-19 pandemic has raised concerns over secondary infections because it has limited treatment options and empiric antimicrobial treatment poses serious risks of aggravating antimicrobial resistance. Many studies have shown that COVID-19 patients are predisposed to developing secondary infections. The prevalence of urinary tract infections (UTI) was evaluated in 248 patients admitted to different hospitals in Erbil city, Iraq. Results showed 138 (55.65%) patients were positive for bacterial growth, of which 72 isolates of Gram-negative and 66 isolates of Gram-positive bacteria were isolated and identified from the urine of COVID-19 patients depending on the 16S rRNA gene using PCR. The predominant obtained bacteria were Staphylococci species, of which isolates belong to 6 species, and the predominant Gram-negative species was Pseudomonas spp. which belongs to 4 species. Also, their susceptibility to 15 antibiotics was tested and it was found that most of the Gram-negative isolates were highly resistant to ampicillin 66(91.66%), amoxicillin 60(83.33%), cephalexin 52(72.22%) and cefixime 50(69.44%). While the most effective antibiotic was imipenem, and with percentage of 26(36.11%), it also showed variable sensitivity to other antibiotics. For Gram-positive bacteria, the highest resistance was against cefixime 40(60.60%), ampicillin 28(42.42%), and 18(27.27%) for both amoxicillin and ciprofloxacin, while the most effective antibiotic was gentamicin, which showed effectiveness against all the Gram-positive isolates. Another part of the study concerned with detection of the existence of ESBLs genes responsible for antibiotic resistance. The results revealed that all the isolates possessed the 16S rRNA gene, whereas blaTEM and blaCTX-M were found to be the most possessed genes in all the isolates, with a percentage of (88.33%).

Levels of IL-6 and IL-8 in complicated versus uncomplicated urinary tract infection

Background: Urinary tract infections (UTIs) are one of the world's most frequent infectious diseases, affecting 150 million people each year and resulting in severe morbidity and high medical expenditures. UTIs can be clinically defined as uncomplicated UTIs (uUTIs) or complicated UTIs (cUTIs) to differentiate infections of benign origin from those with a higher risk of recurrence or progression to severe pathology. The aim of this study was to evaluate interleukin-6 (IL-6) and IL-8 as potential biomarkers in differentiating complicated and uncomplicated Methods: Ninety samples of urine were collected. There were 43 samples from healthy controls and 47 samples from UTI patients, those who have been clinically diagnosed with UTIs by the urologist. The serum IL-6 and IL-8 were measured using an enzyme-linked immunosorbent assay and commercially available kits. Results: The levels of both IL-6 and IL-8 were significantly higher in UTI patient then in control subjects (p=0.001, p=0.001). A significant difference was observed in the mean of level IL-6 between culture positive UTI patients and culture negative UTI patients (p=0.014). In addition, the type of bacterial growth, a significant difference was observed in the mean of serum IL-6 and IL-8 level in UTI caused by gram negative bacteria in comparison with UTI caused by gram positive bacteria. Conclusion: High levels of IL-6 are associated with the growth of gram-negative bacteria, and this indicates that gram-negative bacteria could induce stronger inflammatory responses than gram-positive bacteria. IL-8 levels are higher in UTIs caused by gram-negative bacteria. This result further supported the evidence that gram-negative bacteria are potent inducers of inflammatory responses.