Microbial Infections Research Articles

Enrichment of creatine-gelatin cryogel with Zataria multiflora essential oil and titanium dioxide nanoparticles as a potential wound dressing

The prevalence of microbial infections in wounds, particularly burn wounds, presents a significant medical concern due to the inherent vulnerability of compromised skin to pathogen colonization and invasion. This study focused on the synthesis and evaluation of a creatine-gelatin cryogel, enriched with Zataria multiflora essential oil and titanium dioxide nanoparticles for potential wound dressing applications. The chemical and physical characteristics of the formulation were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy, and mechanical tests. Further studies such as wound fluid absorptivity, water vapor transmission rate, solubility, moisture content, porosity, and release properties were investigated. The release test demonstrated an encapsulation efficiency of 98.8 % and a loading capacity of 16.45 %, signifying a suitable cryogel matrix. The disk diffusion assay demonstrated that the synthesized cryogel had excellent antimicrobial efficacy against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida species. Additionally, the cryogel exhibited great cytocompatibility and hemocompatibility (∼100 %). Our findings suggest that the creatine-gelatin cryogel blend enriched with Zataria multiflora essential oil and titanium dioxide nanoparticles possesses structural integrity, a cell-friendly nature, moisture-retaining capabilities, and biocompatible characteristics. These properties collectively render it an exceptionally suitable material for advanced wound dressings. Moreover, the demonstrated functional properties of the cryogel, including its ability to prevent infection, exhibit antioxidant activity, and retain moisture, underscore its potential for effective burn wound management.

Microbial Infections in IVF Culture System and Recovering Infected Embryos

Microbial Infections in IVF Culture System and Recovering Infected Embryos

Thymol, a Monoterpenoid within Polymeric Iodophor Formulations and Their Antimicrobial Activities.

Antimicrobial resistance (AMR) poses an emanating threat to humanity's future. The effectiveness of commonly used antibiotics against microbial infections is declining at an alarming rate. As a result, morbidity and mortality rates are soaring, particularly among immunocompromised populations. Exploring alternative solutions, such as medicinal plants and iodine, shows promise in combating resistant pathogens. Such antimicrobials could effectively inhibit microbial proliferation through synergistic combinations. In our study, we prepared a formulation consisting of Aloe barbadensis Miller (AV), Thymol, iodine (I2), and polyvinylpyrrolidone (PVP). Various analytical methods including SEM/EDS, UV-vis, Raman, FTIR, and XRD were carried out to verify the purity, composition, and morphology of AV-PVP-Thymol-I2. We evaluated the inhibitory effects of this formulation against 10 selected reference strains using impregnated sterile discs, surgical sutures, gauze bandages, surgical face masks, and KN95 masks. The antimicrobial properties of AV-PVP-Thymol-I2 were assessed through disc diffusion methods against 10 reference strains in comparison with two common antibiotics. The 25-month-old formulation exhibited slightly lower inhibitory zones, indicating changes in the sustained-iodine-release reservoir. Our findings confirm AV-PVP-Thymol-I2 as a potent antifungal and antibacterial agent against the reference strains, demonstrating particularly strong inhibitory action on surgical sutures, cotton bandages, and face masks. These results enable the potential use of the formulation AV-PVP-Thymol-I2 as a promising antimicrobial agent against wound infections and as a spray-on contact-killing agent.

Epidemiology of Microbial Keratitis at a Tertiary Care Hospital in Southern Thailand.

This study aimed to ascertain the microbial profiles and predisposing risk factors for microbial keratitis and to analyze the trend of mixed microbial infection cases over 8 years. In this retrospective analysis, we reviewed the electronic medical records of inpatients diagnosed with microbial keratitis between January 2012 and December 2019. Data on demographics, risk factors, and causative pathogens were analyzed. Multivariate logistic regression models were utilized to identify risk factors associated with pathogens. This study included 640 eyes of 638 patients. Trauma was the most common predisposing risk factor (57.2%), followed by a combination of factors (14.4%). Among diagnostic test results, bacteria, fungi, and mixed pathogens were identified in 46.72%, 46.56%, and 21.41% of cases, respectively. Positive culture results were obtained in 324 eyes (53.6%), with Pseudomonas aeruginosa (25.1%) and Fusarium spp. (17.4%) being the most prevalent pathogens. In the multivariate logistic regression model, contact lens use, presence of diabetes mellitus, and HIV infection were statistically significant risk factors for Pseudomonas aeruginosa infection (p = 0.001, p = 0.046, and p = 0.04, respectively). Trauma was associated with Fusarium spp. infection (p = 0.001). An increase in the percentage of mixed microbial infection cases was observed when comparing the periods of 2016-2019 with 2012-2015 (p = 0.023). Bacteria and fungi are equally common causes of microbial keratitis, with Pseudomonas aeruginosa and Fusarium spp. being the predominant pathogens causing bacterial and fungal infections. Trauma is the primary predisposing risk factor for microbial keratitis. There was a notable increase in mixed infection cases over the study period.

In vitro and in vivo assessment of curcumin-quercetin loaded multi-layered 3D-nanofibroporous matrix prepared by solution blow-spinning for full-thickness burn wound healing

Burn wounds (BWs) cause impairment of native skin tissue and may cause significant microbial infections that demand immediate care. Curcumin (Cur) and quercetin (Que) exhibit antimicrobial, hemocompatibility, ROS-scavenging, and anti-inflammatory properties. However, its instability, water insolubility, and low biological fluid absorption render it challenging to sustain local Cur and Que doses at the wound site. Therefore, to combat these limitations, we employed blow-spinning and freeze-drying to develop a multi-layered, Cur/Que-loaded gelatin/chitosan/PCL (GCP-Q/C) nanofibroporous (NFP) matrix. Morphological analysis of the NFP-matrix using SEM revealed a well-formed multi-layered structure. The FTIR and XRD plots demonstrated dual-bioactive incorporation and scaffold polymer interaction. Additionally, the GCP-Q/C matrix displayed high porosity (82.7 ± 2.07 %), adequate pore size (~121 μm), enhanced water-uptake ability (~675 % within 24 h), and satisfactory biodegradation. The scaffolds with bioactives had a long-term release, increased antioxidant activity, and were more effective against gram-positive (S. aureus) and gram-negative (E. coli) bacteria than the unloaded scaffolds. The in vitro findings of GCP-Q/C scaffolds showed promoted L929 cell growth and hemocompatibility. Additionally, an in vivo full-thickness BW investigation found that an implanted GCP-Q/C matrix stimulates rapid recuperation and tissue regeneration. In accordance with the findings, the Gel/Ch/PCL-Que/Cur NFP-matrix could represent an effective wound-healing dressing for BWs.

Marine Microalgae Schizochytrium sp. S31: Potential Source for New Antimicrobial and Antibiofilm Agent.

The rise of antibiotic-resistant bacteria necessitates the discovery of new, safe, and bioactive antimicrobial compounds. The antibacterial and antibiofilm activity of microalgae makes them a potential candidate for developing natural antibiotics to limit microbial infection in various fields. This study aimed to analyze the antibacterial effect of the methanolic extract of Schizochytrium sp. S31 microalgae by broth microdilution and spot plate assays. The antibacterial effects of Schizochytrium sp. S31 extract was studied on gramnegative pathogens, Pseudomonas aeruginosa, Escherichia coli 35218, Klebsiella pneumonia, which cause many different human infections, and the gram-positive pathogen Streptococcus mutans. At the same time, the antibiofilm activity of the Schizochytrium sp. S31 extract on Pseudomonas aeruginosa and Escherichia coli 35218 bacteria were investigated by crystal violet staining method. Schizochytrium sp. S31 extract at a 60% concentration for 8 hours displayed the highest antibacterial activity against P. aeruginosa, E. coli 35218, and K. pneumonia, with a decrease of 87%, 92%, and 98% in cell viability, respectively. The experiment with Streptococcus mutans revealed a remarkable antibacterial effect at a 60% extract concentration for 24 hours, leading to a notable 93% reduction in cell viability. Furthermore, the extract exhibited a dose-dependent inhibition of biofilm formation in P. aeruginosa and E. coli 35218. The concentration of 60% extract was identified as the most effective dosage in terms of inhibition. This research emphasizes the potential of Schizochytrium sp. S31 as a natural antibacterial and antibiofilm agent with promising applications in the pharmaceutical sectors. This is the first study to examine the antibacterial activity of Schizochytrium sp. S31 microalgae using broth microdilution, spot plate assays, and the antibiofilm activity by a crystal staining method. The findings of this study show that Schizochytrium sp. S31 has antibacterial and antibiofilm activities against critical bacterial pathogens.

Toll-like receptors in health and disease.

Toll-like receptors (TLRs) are inflammatory triggers and belong to a family of pattern recognition receptors (PRRs) that are central to the regulation of host protective adaptive immune responses. Activation of TLRs in innate immune myeloid cells directs lymphocytes to produce the most appropriate effector responses to eliminate infection and maintain homeostasis of the body's internal environment. Inappropriate TLR stimulation can lead to the development of general autoimmune diseases as well as chronic and acute inflammation, and even cancer. Therefore, TLRs are expected to be targets for therapeutic treatment of inflammation-related diseases, autoimmune diseases, microbial infections, and human cancers. This review summarizes the recent discoveries in the molecular and structural biology of TLRs. The role of different TLR signaling pathways in inflammatory diseases, autoimmune diseases such as diabetes, cardiovascular diseases, respiratory diseases, digestive diseases, and even cancers (oral, gastric, breast, colorectal) is highlighted and summarizes new drugs and related clinical treatments in clinical trials, providing an overview of the potential and prospects of TLRs for the treatment of TLR-related diseases.

Genus Shewanella: A Potential Intestinal Colonizer Associated With Post-Operative Surgical Site Infections in Coastal Regions.

Background: This study aims to elucidate the clinical characteristics of Shewanella-related surgical site infections (SSIs) and assess the risk of mortality in patients by establishing a predictive model. Patients and Methods: A retrospective analysis of medical history and laboratory data of Shewanella-related SSI patients over the past decade was conducted via the electronic medical record (EMR) system. A predictive model for mortality risk in Shewanella-related SSI patients was established using plasma interleukin-6 (IL-6) levels combined with the Howell-PIRO scoring system. Results: Over the past 10 years, 45 strains of Shewanella were isolated from specimens such as bile, drainage fluid, and whole blood in patients with digestive tract SSIs. Among them, 21 of 45 (46.67%) patients underwent malignant tumor resection of the digestive system, 14 of 45 (31.11%) underwent endoscopic retrograde cholangiopancreatography (ERCP) common bile duct exploration or the stone removal, and seven of 45 (15.56%) were trauma repair patients with fractures and abdominal injuries. Among the 45 Shewanella-related SSI patients, 10 died within 30 days of infection, six cases involved infections with more than two other types of bacteria. The combined use of IL-6 and Howell-PIRO scores for mortality risk assessment yielded an receiver operating characteristic (ROC) curve with an area under the curve (AUC) of 0.9350, a positive predictive value of 92.71%, a negative predictive value of 94.58%, a diagnostic sensitivity of 95.35%, and a diagnostic specificity of 92.14%-all higher than the model using IL-6 or Howell-PIRO scores alone. Conclusions: We found that residents in coastal areas faced an increased risk of Shewanella-related SSI. Moreover, the higher the number of concurrent microbial infections occurring alongside Shewanella-related SSI, the greater the mortality rate among patients. The combined application of plasma IL-6 levels and the Howell-PIRO scoring system is beneficial for assessing patient mortality risk and guiding timely and proactive clinical interventions.

Poly-3-hydroxybutyrate-silver nanoparticles membranes as advanced antibiofilm strategies for combatting peri-implantitis

Dental implant success is threatened by peri-implantitis, an inflammation leading to implant failure. Conventional treatments struggle with the intricate microbial and host factors involved. Antibacterial membranes, acting as barriers and delivering antimicrobials, may offer a promising solution. Thus, this study highlights the potential of developing antibacterial membranes of poly-3-hydroxybutyrate and silver nanoparticles (Ag Nps) to address peri-implantitis challenges, discussing design and efficacy against potential pathogens.Electrospun membranes composed of PHB microfibers and Ag Nps were synthesized in a blend of DMF/chloroform at three different concentrations. Various studies were conducted on the characterization and antimicrobial activity of the membranes. The synthesized Ag Nps ranged from 4 to 8 nm in size. Furthermore, Young's modulus decreased, reducing from 13.308 MPa in PHB membranes without Ag Nps to 0.983 MPa in PHB membranes containing higher concentrations of Ag Nps. This demonstrates that adding Ag Nps results in a less stiff membrane. An increase in elongation at break was noted with the rise in Ag Nps concentration, from 23.597 % in PHB membranes to 60.136 % in PHB membranes loaded with Ag Nps.The antibiotic and antibiofilm activity of the membranes were evaluated against Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus mutans, and Candida albicans. The results indicated that all PHB membranes containing Ag Nps exhibited potent antibacterial activity by inhibiting the growth of biofilms and planktonic bacteria. However, inhibition of C. albicans occurred only with the PHB-Ag Nps C membrane.These findings emphasize the versatility and potential of Ag Nps-incorporated membranes as a multifunctional approach for preventing and addressing microbial infections associated with peri-implantitis. The combination of antibacterial and antibiofilm properties in these membranes holds promise for improving the management and treatment of peri-implantitis-related complications.

Quinolone scaffolds as potential drug candidates against infectious microbes: a review.

Prevalence of microbial infections and new rising pathogens are signified as causative agent for variety of serious and lethal health crisis in past years. Despite medical advances, bacterial and fungal infections continue to be a rising problem in the health care system. As more bacteria develop resistance to antibiotics used in therapy, and as more invasive microbial species develop resistance to conventional antimicrobial drugs. Relevant published publications from the last two decades, up to 2024, were systematically retrieved from the MEDLINE/PubMed, SCOPUS, EMBASE, and WOS databases using keywords such as quinolones, anti-infective, antibacterial, antimicrobial resistance and patents on quinolone derivatives. With an approach of considerable interest towards novel heterocyclic derivatives as novel anti-infective agents, researchers have explored these as essential tools in vistas of drug design and development. Among heterocycles, quinolones have been regarded extremely essential for the development of novel derivatives, even able to tackle the associated resistance issues. The quinolone scaffold with its bicyclic structure and specific functional groups such as the carbonyl and acidic groups, is indeed considered a valuable functionalities for further lead generation and optimization in drug discovery. Besides, the substitution at N-1, C-3 and C-7 positions also subjected to be having a significant role in anti-infective potential. In this article, we intend to highlight recent quinolone derivatives based on the SAR approach and anti-infective potential such as antibacterial, antifungal, antimalarial, antitubercular, antitrypanosomal and antiviral activities. Moreover, some recent patents granted on quinolone-containing derivatives as anti-infective agents have also been highlighted in tabular form. Due consideration of this, future research in this scaffold is expected to be useful for aspiring scientists to get pharmacologically significant leads.

Heterogeneity of macrophage activation syndrome and treatment progression.

Macrophage activation syndrome (MAS) is a rare complication of autoimmune inflammatory rheumatic diseases (AIIRD) characterized by a progressive and life-threatening condition with features including cytokine storm and hemophagocytosis. Predisposing factors are typically associated with microbial infections, genetic factors (distinct from typical genetically related hemophagocytic lymphohistiocytosis (HLH)), and inappropriate immune system overactivation. Clinical features include unremitting fever, generalized rash, hepatosplenomegaly, lymphadenopathy, anemia, worsening liver function, and neurological involvement. MAS can occur in various AIIRDs, including but not limited to systemic juvenile idiopathic arthritis (sJIA), adult-onset Still's disease (AOSD), systemic lupus erythematosus (SLE), Kawasaki disease (KD), juvenile dermatomyositis (JDM), rheumatoid arthritis (RA), and Sjögren's syndrome (SS), etc. Although progress has been made in understanding the pathogenesis and treatment of MAS, it is important to recognize the differences between different diseases and the various treatment options available. This article summarizes the cell types and cytokines involved in MAS-related diseases, the heterogeneity, and treatment options, while also comparing it to genetically related HLH.

Titania NPs: A Review of Their Versatile Roles in Medicine and Synthesis Methods

Abstract: In this study, we investigate the various applications of titania in the medical field. Titania, renowned for its biocompatibility and distinctive properties, plays a significant role in pharmaceutical formulations. It is vital in coating tablets and capsules, improving drug stability and appearance. Additionally, titania nanoparticles (NPs) facilitate targeted drug delivery systems, enhancing therapeutic outcomes. Furthermore, we explore the promising prospects of titania-based photocatalysts in photodynamic therapy, highlighting their potential to transform cancer treatment and combat microbial infections. This comprehensive examination underscores the diverse and promising opportunities in which titania significantly advances medicine.

Antibacterial and anti-biofilm activities of antibiotic-free phosphatidylglycerol/docosahexaenoic acid lamellar and non-lamellar liquid crystalline nanoparticles

Infectious diseases, particularly those associated with biofilms, are challenging to treat due to an increased tolerance to commonly used antibiotics. This underscores the urgent need for innovative antimicrobial strategies. Here, we present an alternative simple-by-design approach focusing on the development of biocompatible and antibiotic-free nanocarriers from docosahexaenoic acid (DHA) that has the potential to combat microbial infections and phosphatidylglycerol (DOPG), which is attractive for use as a biocompatible prominent amphiphilic component of Gram-positive bacterial cell membranes. We assessed the anti-bacterial and anti-biofilm activities of these nanoformulations (hexosomes and vesicles) against S. aureus and S. epidermidis, which are the most common causes of infections on catheters and medical devices by different methods (including resazurin assay, time-kill assay, and confocal laser scanning microscopy on an in vitro catheter biofilm model). In a DHA-concentration-dependent manner, these nano-self-assemblies demonstrated strong anti-bacterial and anti-biofilm activities, particularly against S. aureus. A five-fold reduction of the planktonic and a four-fold reduction of biofilm populations of S. aureus were observed after treatment with hexosomes. The nanoparticles had a bacteriostatic effect against S. epidermidis planktonic cells but no anti-biofilm activity was detected. We discuss the findings in terms of nanoparticle-bacterial cell interactions, plausible alterations in the phospholipid membrane composition, and potential penetration of DHA into these membranes, leading to changes in their structural and biophysical properties. The implications for the future development of biocompatible nanocarriers for the delivery of DHA alone or in combination with other anti-bacterial agents are discussed, as novel treatment strategies of Gram-positive infections, including biofilm-associated infections.

Chemical profiling and antimicrobial potential of crude extract and essential oil from Conyza bonariensis leaves

Background and objectives: Microbial infections have made significant contributions to the global health burden, particularly in developing countries with lagging economies. Challenges arising from the evolution of antimicrobial resistant (AMR) bacteria have led to the search for novel antimicrobial agents, especially those derived from medicinal plants. Therefore, this study aimed to assess the antibacterial activity of ethyl acetate crude extracts and essential oils from C. bonariensis collected from the Mbeya region of Tanzania. Methods: Initial experimental activities involved preparation of crude extracts and essential oil, which were then, tested for antimicrobial activity against selected test organisms (Staphlococcus aureus (ATCC29213), Bacillus subtilis (ATCC6051), Escherichia coli (ATCC8736), Salmonella typhi (ATCC6539), and Candida albicans (DSM1665)) by using the disc diffusion method. On the other hand, the chemical composition profiling of ethyl acetate and essential oils was performed by gas chromatography mass spectrometry (GC-MS). Results: The crude extracts and essential oil of C. bonariensis leaves from Tanzania demonstrated to have antibacterial and antifungal activity. The minimum inhibition concentration (MIC) of leaves ethyl acetate crude extract was 25 mg/mL > MIC > 12.5 mg/mL for tested organisms, with the exception of C. albicans, where the MIC was 50 mg/mL > MIC > 25 mg/mL. Similary, for all tested organisms, the MIC of leaves essential oils was :1 > MIC > l:2, except S. typhi, where the MIC was 2:1 > MIC > 1:1. On the other hand, 2,4-di-tert-butyl phenol in leaves crude extracts had the highest percentage composition of peak area (41%); whereas, in essential of, 2,4-Di-tert-butyl phenol had the highest percentage composition (38.8%). Conclusions: The present findings have demonstrated antimicrobial potential of ethyl acetate crude extract and essential oil of C. bonariensis leaves from Tanzania, and validate the wide use of the plant by local communities, particularly the local community of Mbeya region in Tanzania.

Selective Bacterial Growth Inactivation by pH-Sensitive Sulfanilamide Functionalized Carbon Dots.

Carbon dots (CDs) were synthesized hydrothermally by mixing citric acid (CA) and an antifolic agent, sulfanilamide (SNM), employed for pH sensing and bacterial growth inactivation. Sulfanilamide is a prodrug; aromatic hetero cyclization of the amine moiety along with other chemical modifications produces an active pharmacological compound (chloromycetin and miconazole), mostly administered for the treatment of various microbial infections. On the other hand, the efficacy of the sulfanilamide molecule as a drug for antimicrobial activity was very low. We anticipated that the binding of the sulfanilamide molecule on the carbon dot (CD) surface may form antibacterial CDs. Citric acid was hybridized with sulfanilamide during the hydrothermal preparation of the CDs. The molecular fragments of bioactivated sulfanilamide molecule play a crucial role in bacterial growth inactivation for Gram-positive and Gram-negative bacteria. The functional groups of citric acid and sulfanilamide were conserved during the CD formation, facilitating the zwitterionic behavior of CDs associated with its photophysical activity. At low concentrations of CDs, the antibacterial activity was apparent for Gram-positive bacteria only. This Gram-positive bacteria selectivity was also rationalized by zeta potential measurement.

Design and Nanoengineering of Photoactive Antimicrobials for Bioapplications: from Fundamentals to Advanced Strategies

AbstractCurrently, microbial infections have posed an arduous challenge to global public health, whereas the rise of antibiotic resistance is rendering traditional antibiotic therapies futile, prompting the development of new antimicrobial technologies. Photoactive nanomaterials have thus garnered a thriving interest for disinfection owing to their superior antibacterial efficaciousness, favorable biosafety, and rapidness and spatiotemporal precision in excreting bactericidal actions. The review summarizes recent advances and emerging trends in the design, nanoengineering, and bioapplications of photoactive antimicrobials. It commences by elaborating fundamental theories on bacterial resistance, and antibacterial mechanisms of nanomaterials and phototherapy. Subsequently, the regulation of the antibacterial effectiveness of photoactive nanomaterials is comprehensively discussed, centering on criteria and strategies for tuning photoabsorption spectra, photothermal conversion, and photocatalytic efficiency, alongside tactics for enabling synergistic therapies. This is followed by comparative analyses of techniques and modalities for synthesizing and engineering photoactive nanomaterials with diverse structures, forms, and functionalities. Thereafter, the state‐of‐the‐art applications of phototherapies across various medical sectors are portrayed, and key challenges and opportunities are finally discussed to spur future innovations and translation. This review is envisaged to provide useful guidance for devising and developing nanomaterials‐based photoresponsive antimicrobials with application‐specific materials properties and biological functions.

Selective antibacterial and antibiofilm activity of chlorinated hemicyanine against gram-positive bacteria

Antibiotic-free therapies are highly needed due to the limited success of conventional approaches especially against biofilm related infections. In this direction, antimicrobial phototherapy, either in the form of antimicrobial photothermal therapy (aPTT) or antimicrobial photodynamic therapy (aPDT), have appeared to be highly promising candidates in recent years. These are local and promising approaches for antibiotic resistant bacterial infections and biofilms. Organic small photosensitizers (PSs) are extensively preferred in antimicrobial phototherapy applications as they offer a great opportunity to combine therapeutic action (aPTT, aPDT or both) with fluorescence imaging on a single molecule. In this study, the bactericidal effect of cationic chlorinated hemicyanine (Cl-Hem)-based type I PS, which can function as a dual aPDT/aPTT agent, was investigated on both planktonic cells and biofilms of different gram-positive (E. faecalis and S. epidermidis) and gram-negative bacteria (P. aeruginosa and K. pneumoniae) with and without 640 nm laser irradiation. Cl-Hem was shown to induce a selective phototheranostic activity against gram-positive bacteria (E. faecalis and S. epidermidis). Cl-Hem exhibited both dose and laser irradiation time dependent bactericidal effect on planktonic and biofilms of S. epidermidis. These results clearly showed that highly potent Cl-Hem can treat resistant microbial infections, while allowing fluorescence detection at the same time. High biofilm reduction observed with combined aPDT/aPTT action of Cl-Hem together with its non-cytotoxic nature points out that Cl-Hem is a promising PS for antibacterial and antibiofilm treatments.

Broad-spectrum activity of membranolytic cationic macrocyclic peptides against multi-drug resistant bacteria and fungi

The emergence of multidrug-resistant (MDR) strains causes severe problems in the treatment of microbial infections owing to limited treatment options. Antimicrobial peptides (AMPs) are drawing considerable attention as promising antibiotic alternative candidates to combat MDR bacterial and fungal infections. Herein, we present a series of small amphiphilic membrane-active cyclic peptides composed, in part, of various nongenetically encoded hydrophilic and hydrophobic amino acids. Notably, lead cyclic peptides 3b and 4b showed broad-spectrum activity against drug-resistant Gram-positive (MIC = 1.5–6.2 µg/mL) and Gram-negative (MIC = 12.5–25 µg/mL) bacteria, and fungi (MIC = 3.1–12.5 µg/mL). Furthermore, lead peptides displayed substantial antibiofilm action comparable to standard antibiotics. Hemolysis (HC50 = 230 µg/mL) and cytotoxicity (>70 % cell viability against four different mammalian cells at 100 µg/mL) assay results demonstrated the selective lethal action of 3b against microbes over mammalian cells. A calcein dye leakage experiment substantiated the membranolytic effect of 3b and 4b, which was further confirmed by scanning electron microscopy. The behavior of 3b and 4b in aqueous solution and interaction with phospholipid bilayers were assessed by employing nuclear magnetic resonance (NMR) spectroscopy in conjunction with molecular dynamics (MD) simulations, providing a solid structural basis for understanding their membranolytic action. Moreover, 3b exhibited stability in human blood plasma (t1/2 = 13 h) and demonstrated no signs of resistance development against antibiotic-resistant S. aureus and E. coli. These findings underscore the potential of these newly designed amphiphilic cyclic peptides as promising anti-infective agents, especially against Gram-positive bacteria.

Photoactive cationic conjugated microporous polymers containing pyrimidine with an ‘adsorption-kill’ antibacterial strategy for infected wound healing

Pathogenic bacterial invasion leads to severe inflammation that hinders wound healing, and it has become a major medical threat worldwide. Photodynamic therapy (PDT) has emerged as a promising strategy for treating microbial infection; however, developing a dressing with PDT effect and excellent biological functions poses a formidable challenge. Herein, a novel cationic pyrimidine-modified conjugated microporous polymer, BPyMe-CMP, was rationally designed and synthesized via a Sonogashira-Hagiwara and SN2 substitution reaction. The BPyMe-CMP exhibited weak interfacial charge transfer resistance and demonstrated superior photoinducible carrier separation, thereby displaying an excellent photoelectric response. Consequently, the BPyMe-CMP could readily generate reactive oxygen species under visible light irradiation to kill bacteria. In addition to enhancing the photogenerated electron transfer process, BPyMe-CMP also provided abundant attraction sites for bacteria to reinforce the antibacterial ability. The deposition of BPyMe-CMP onto polyvinyl alcohol-modified silk fibroin (SF/PVA) film served as a wound dressing to promote healing. The in vitro and in vivo experiments revealed that the SF/PVA@BPyMe-CMP induced M2-type macrophage polarization, promoted L929 fibroblast migration, exhibited bactericidal activity, and induced angiogenesis, which synergistically accelerated the healing of methicillin-resistant Staphylococcus aureus-infected wounds. This study provides data support to advance the construction of a multi-functional wound dressing based on pyrimidination and cationization for the treatment and rapid healing of infected wounds.

ASSOCIATION OF TYPE 2 DIABETES MELLITUS AND CANDIDIASIS : A TEN YEARS SYSTEMATIC REVIEW

Background: Diabetes mellitus is a chronic disease that may reduce resistance to microbial infection of tissues and decrease tissue repair capacity. It is both an endocrine and a metabolic dysfunction involving the control of blood glucose levels, resulting in hyperglycemia. The aim: The aim of this study to show about association of type 2 diabetes mellitus and candidiasis. Methods: By the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) 2020, this study was able to show that it met all of the requirements. This search approach, publications that came out between 2014 and 2024 were taken into account. Several different online reference sources, like Pubmed, SagePub, and Sciencedirect were used to do this. It was decided not to take into account review pieces, works that had already been published, or works that were only half done. Result: Five publications were found to be directly related to our ongoing systematic examination after a rigorous three-level screening approach. Subsequently, a comprehensive analysis of the complete text was conducted, and additional scrutiny was given to these articles. Conclusion: Diabetic patients had a higher candidal carriage rate and a variety of candidal species that were resistant to azole antifungal agents.