Burn Wound Infection Research Articles

Antibiotic resistance of Escherichia coli isolates obtained from burn patients

Bacterial resistance to widely used antibiotics is an emerging global health issue and causes a huge problem in burn patients. Despite important developments in antimicrobial treatments, the risk of infection-associated mortality rate in burn patients is comparatively high. Escherichia coli is one of the most common causative agents of burn wound infections. Therefore, this study aimed to identify and characterize E. coli isolates from burn wounds using the VITEK 2 system and to test their antibiotic resistance to the most commonly used antibiotics with the disc diffusion method. In our study, of 147 clinical samples obtained from burn patients, 25 (%17) were detected as positive for E. coli. All these isolates were found to be resistant to cephalothin, cephradine, piperacillin, and rifampin antibiotics. The resistance to amoxicillin+clavulanic acid and ampicillin was 96% (± 8%), which was followed by amikacin and cefotaxime with a 92% (± 11%) resistance rate. On the other hand, imipenem (96% ± 8%), tetracycline (88% ± 13%), and gentamicin (76% ± 17%) were the antibiotics that showed the highest sensitivity against E. coli isolates. The multidrug-resistant bacteria are one of the main issues for clinical applications, so their characterization is vital in developing a proper treatment strategy. This study concluded that E. coli exists in burn wounds and might cause wound infection due to its resistance to different antibiotics.

Antibiofilm and antimicrobial activity of Lactobacillus cell free supernatant against Pseudomonas aeruginosa isolated from burn wounds.

The present study investigated the antimicrobial and anti-biofilm effects of indigenous Lactobacillus probiotic strains on Pseudomonas aeruginosa isolated from burn wound infection in laboratory conditions. The effect of 7 probiotic strains isolated from infant faeces on the pathogenicity factors of P. aeruginosa, including protease, elastase, antibiofilm and antipyocyanin was measured. Also, diffusion methods in the well and micro broth dilution were used to evaluate the antimicrobial activity of probiotics. All tests were performed in triplicate. A negative control and a positive control were used for each test. SPSS version 22 software was used for statistical analysis, and a p < 0.05 was considered statistically significant. A total of 30 clinical isolates of P. aeruginosa were isolated. The elastolytic activity of P. aeruginosa isolates decreased after adding Cell free supernatant (CFS) of each Lactobacillus. L1, L4, L5, and L6 strains had a 100% inhibitory effect on pathogen isolates. L3 and L7 strains had the lowest inhibitory effect. The inhibitory effect of CFS extracted from lactobacilli on protease production by P. aeruginosa. L1, L4, L5, and L6 strains had an inhibitory effect on all tested isolates. L2, L3, and L7 strains had a less inhibitory effect. L4 strain had the highest inhibitory effect on pyocyanin production by P. aeruginosa (50%), followed by L5 (43.3%), L1 (40%), and L6 (23.3%) strains. L3 and L7 strains had no inhibitory effect on the pyocyanin production of P. aeruginosa isolates. It was found that the CFS of 4 isolates (L1, L4, L5, and L6) was the most active extract and had a 100% inhibitory effect against biofilm formation of all P. aeruginosa strains. The L3 strain had the least inhibitory effect against the biofilm formation of pathogens. Overall, this study showed that probiotics could be promising alternatives to combat the pathogenicity of P. aeruginosa in burn wounds.

Bromelain-based enzymatic burn debridement: A systematic review of clinical studies on patient safety, efficacy and long-term outcomes.

In 2012 the European Medicines Agency approved a pineapple stem-derived Bromelain-based debridement concentrate of proteolytic enzymes (NexoBrid®, MediWound Ltd, Yavne, Israel) for adult deep burns. Over 10 000 patients have been successfully treated with NexoBrid® globally, including in the US. The aim of our study is to perform a systematic review of the current literature on Nexobrid® outcomes. We conducted a literature search in PubMed, Google Scholar, Embase, and other search engines (2013-2023). The online screening process was performed by two independent reviewers with the Covidence tool. The protocol was reported using the Preferred Reporting Items for Systematic Review and Meta-Analyses, and it was registered at the International Prospective Register of Systematic Reviews of the National Institute for Health Research. We identified 103 relevant studies of which 34 were found eligible. The included studies report the positive effects of Nexobrid® on burn debridement, functional and cosmetic outcomes, scarring, and quality of life. Also, they validate the high patient satisfaction thanks to enhanced protocols of analgosedation and/or locoregional anaesthesia during Bromelain-based debridement. Two studies investigate potential risks (coagulopathy, burn wound infection) which concluded there is no strong evidence of these adverse events. NexoBrid® is a safe, selective, non-surgical eschar removal treatment modality. The benefits of Bromelain-based debridement are faster debridement and healing times, reduced operations, length of stay, cases of sepsis, blood transfusions, and prevention of compartment syndrome. Existing evidence suggests that the indications and the role of Bromelain-based debridement are expanding to cover "off-label" cases with significant benefits to the global healthcare economy.

Detection of exopolysaccharides (algD, pelF, and pslD) genes in burn wound Pseudomonas aeruginosa isolates

Abstract Background: Pseudomonas aeruginosa biofilm is an essential component of virulence that plays a significant role in antimicrobial resistance and chronic burn wound infections. Objective: This study aimed to investigate the biofilm formation capacity of P. aeruginosa isolated from chronic burn wound from January to May 2022 by biochemical and molecular techniques. Materials and Methods: Quantification of biofilm was performed based on tube method for local isolates of P. aeruginosa after growing on brain heart Broth. The genes encoding exopolysaccharides (algD, pelF, and pslD) were targeted by using conventional polymerase chain reaction (PCR). Results: The results showed that 92.6% of isolates were biofilm former, interestingly 68% of isolates were considered as strong former comparing with other biofilm categories. Gel electrophoresis result of PCR products presented clear bands for algD and psID genes with percentages (96%) and (3.7%) respectively. However, there was no PCR product for pelf gene among all isolates. Conclusion: The prevalence of algD, the large operon necessary for alginate production, was high among P. aeruginosa biofilm producer in this study and it can be an essential agent in the pathogenicity of P. aeruginosa burn wound infections comparing with other biofilm genes (pelF and pslD) of exopolysaccharide structure.

The potential therapeutic impact of a topical bacteriophage preparation in treating Pseudomonas aeruginosa-infected burn wounds in mice

AimThis study compared a topical formulation containing lytic phages with a routine antibiotic in the murine model of burn/Pseudomonas aeruginosa infected wound healing. Methods & MaterialsIsolated and purified lytic bacteriophages from hospital sewage were added to the polyethylene glycol (PEG) based ointment. A second-degree burned wound on the back of twenty-four adult female mice was created. The wounds were infected subcutaneously with 100 μL of 1 × 102−3 CFU/mL P. aeruginosa. After 24 h, mice were randomly assigned to one of four groups: mice received a standard antibiotic (antibiotic-treated group), mice received an ointment without bacteriophage (PEG-based group), mice received a PEG-ointment with bacteriophage (bacteriophage-treated group), or mice received no treatment (untreated-control group). Every two days, the contraction of burned wounds, physical activity, and rectal body temperature were recorded. On day 10, mice were sacrificed, and the wounds were cut off and evaluated histopathologically. ResultsIn ointments containing PEG, bacteriophages were active and stable. The mice receiving bacteriophage and PEG-based ointment had substantially different wound contraction in primary wound healing (P = 0.001). When compared to the control group, the bacteriophage-treated group showed significant variations in wound contraction (P = 0.001). The wound contraction changed significantly between the antibiotic and PEG-based groups (P = 0.002). In all groups, physical activity in mice improved over time, with significant differences (P = 0.001). When the 8th day was compared to the days 2, 4, and 6, significant changes were found (P = 0.001, P = 0.02, and P = 0.02, respectively). Both the positive control and bacteriophage-treated groups showed perfect wound healing histopathologically. However, no significant variations in microscopic histopathological criteria were found between the groups. ConclusionFormulated phage ointment could be a promising approach for treating infected burn wounds infected by P. aeruginosa in mice with no allergic reactions.

A Bacteriophage Microgel Effectively Treats the Multidrug-Resistant Acinetobacter baumannii Bacterial Infections in Burn Wounds.

Multidrug-resistant (MDR) Acinetobacter baumannii (A. baumannii) is one of the major pathogens present in burn wound infections. Biofilm formation makes it further challenging to treat with clinically available antibiotics. In the current work, we isolated the A. baumannii-specific bacteriophages (BPABΦ1), loaded into the chitosan microparticles followed by dispersion in gel, and evaluated therapeutic efficacy against MDR A. baumannii clinical strains. Isolated BPABΦ1 were found to belong to the Corticoviridae family, with burst size 102.12 ± 2.65 PFUs per infected host cell. The BPABΦ1 loaded chitosan microparticles were evaluated for quality attributes viz. size, PDI, surface morphology, in vitro release, etc. The developed formulation exhibited excellent antibiofilm eradication potential in vitro and effective wound healing after topical application.

Effect of curcumin nanoparticles and alcoholic extract of Falcaria vulgaris on the growth rate, biofilm, and gene expression in Pseudomonas aeruginosa isolated from burn wound infection.

This study aimed to investigate the effect of Curcumin nanoparticles and alcoholic extract of Falcaria vulgaris on the growth rate, biofilm, and gene expression in Pseudomonas aeruginosa isolated from burn wound infection. The alcoholic extract of Falcaria vulgaris was purchased from Pasargad Company. Curcumin nanoparticles were synthesized. Antibacterial activity of Curcumin nanoparticles and alcoholic extract of Falcaria vulgaris was investigated by microdilution method alone and in combination. Biofilm inhibitory was investigated by microtitrplate method. Effect of Curcumin nanoparticles and alcoholic extract of Falcaria vulgaris were evaluated on algD gene expression via Real-Time PCR. Cytotoxicity was evaluated by MTT assay on HDF cell line. Then, the data were analyzed using SPSS software. Synthesized Curcumin nanoparticles were approved by Fourier Transform Infrared (FTIR), and Scanning Electron Microscope. The alcoholic extract of Falcaria Vulgaris showed significant antibacterial activity against multidrug resistance (MDR) P. aeruginosa isolates at a concentration of 156.25µg/mL. Moreover, MIC of the curcumin nanoparticle for isolates was 625µg/mL. Based on fraction inhibition concentration, synergy, and the additive effect were shown against %7.7, and %93.3 of MDRs, respectively. The sub-MIC concentration of the binary compound reduced biofilms and algD gene expression in P. aeruginosa isolates. The Biological function of HDF cell lines was desirable after the effect of the binary compound. Regarding our results, this combination can be suggested as a promising agent in terms of biofilm inhibitory and antimicrobial properties.

Using the Galleria mellonella burn wound and infection model to identify and characterize potential wound probiotics.

Burn wound infection is the leading cause of mortality among burn wound patients. One of the most commonly isolated bacterial burn wound pathogens is Pseudomonas aeruginosa, a notorious nosocomial multidrug-resistant pathogen. As a consequence of its recalcitrance to frontline antibiotic therapy, there is an urgent need to develop alternative treatment avenues to tackle this pathogen. One potential alternative infection prevention measure is to seed the wound bed with probiotic bacteria. Several species of Lactobacillus, a common commensal bacterium, have been previously reported to display growth inhibition activity against wound pathogens. Various species of this genus have also been shown to augment the wound healing process, which makes it a promising potential therapeutic agent. Due to the complexity of the burn wound trauma and burn wound infection, an in vivo model is required for the development of novel therapeutics. There are multiple in vivo models that are currently available, the most common among them being the murine model. However, mammalian burn wound infection models are logistically challenging, do not lend themselves to screening approaches and come with significant concerns around ethics and animal welfare. Recently, an invertebrate burn wound and infection model using G. mellonella has been established. This model addresses several of the challenges of more advanced animal models, such as affordability, maintenance and reduced ethical concerns. This study validates the capacity of this model to screen for potential wound probiotics by demonstrating that a variety of Lactobacillus spp. can limit P. aeruginosa burn wound infection and improve survival.

Antimicrobial hydrogel with multiple pH-responsiveness for infected burn wound healing

Antimicrobial hydrogel with multiple pH-responsiveness for infected burn wound healing

Anti-Biofilm Enzymes-Assisted Antibiotic Therapy against Burn Wound Infection by Pseudomonas aeruginosa.

Pseudomonas aeruginosa can form biofilms at the site of burn wound, leading to infection and the failure of treatment regimens. The previous in vitro study demonstrated that a combination of the quorum-quenching enzyme AidHA147G and the extracellular matrix hydrolase PslG was effective in inhibiting biofilm and promoting antibiotic synergy. The aim of the present study was to evaluate the efficacy of this combination of enzymes in conjunction with tobramycin in treating burn wound infected with P. aeruginosa. The results showed that this treatment was effective in quorum-quenching and biofilm inhibition on infected wounds. Compared with the tobramycin treatment only, simultaneous treatment with the enzymes and antibiotics significantly reduced the severity of tissue damage, decreased the bacterial load, and reduced the expression of the inflammatory indicators myeloperoxidase (MPO) and malondialdehyde (MDA). Topical application of the enzymes also reduced the bacterial load and inflammation to some extent. These results indicate that the combined-enzyme approach is a potentially effective treatment for P. aeruginosa biofilm infections of burn wounds.

New findings about comparing the effects of antibiotic therapy and phage therapy on memory and hippocampal pyramidal cells in rats.

Pseudomonas aeruginosa is a significant cause of infection in burn wounds. Antibiotics are widely used to treat infectious diseases, and alongside their therapeutic benefits, they can damage host cells. Significant side effects, such as nephrotoxicity and neurotoxicity, are observed in 60% of patients treated with colistin. Therefore, using a suitable alternative instead of antibiotics is paramount. This study aimed to investigate the effects of phage therapy and antibiotic therapy on memory function in rats with P. aeruginosa infected burn wounds. Adult male rats were divided into three groups: (1) infected without treatment (control), (2) infected and treated with colistin antibiotic (3,000,000 international units/kg/day), and (3) infected and treated with 100 μL of phage suspension (approximately 109 PFU/mL). In all animals, after anesthesia, a third-degree burn was created in the back area. One hour later, treatment was performed for seven consecutive days. Passive avoidance test, novel object recognition test, locomotion activity, hippocampal neuron count, and oxidative stress measurement in blood serum were performed. In antibiotic-treated group memory recall, recognition index, number of healthy neurons in CA1, CA2, and CA3 hippocampus areas and the amounts of MDA, and FRAP significantly decreased compared with the control group. The phage-treated group was not shown any harmful effect on the memory process, number of healthy hippocampal neurons, and showed more positive effects in blood serum examinations compared with the antibiotic group. Phage therapy could be a safe and effective alternative to antibiotics in the treatment of burn-related infections.

Antibacterial and Cytotoxic Activity of Mentha arvensis L. Leaves Methanolic Extract In vitro

Treatment with herbal drugs is considered one of the oldest and safest methods for treating various diseases. Mentha arvensis is a medicinal plant used worldwide in the pharmaceutical industry for its antibacterial, anticancer, antiallergic, and anti-inflammatory properties. In the present study, the antibacterial activity of the methanolic extract of M. arvensis leaves was tested at different concentrations (50, 100, 150, and 200 µg/ml) against bacteria isolated from human burn wound infections, including Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus. The results demonstrated that at concentrations of 100, 150, and 200 µg/ml, the methanolic extract exhibited strong antibacterial activity against S. aureus and P. aeruginosa, while K. pneumoniae isolates were resistant to the extract at all tested concentrations. Further, the cytotoxic activity of the methanolic extract was assessed at various concentrations (100, 140, 160, 180, 220, and 250 µg/ml) against two cell lines: the RD tumor cell line and Vero normal cell line. The higher concentrations of the extract (220 and 250 µg/ml) showed potent cytotoxic effects on the RD cell line after 72 hours in a dose- and time-dependent manner. In contrast, the extract exhibited lower cytotoxic effects on Vero cells at the same concentrations after 72 h.

Injectable Antibacterial Hydrogel with Asiaticoside-Loaded Liposomes and Ultrafine Silver Nanosilver Particles Promotes Healing of Burn-Infected Wounds.

Post-injury infection and wound healing are recurrent daily life problems. Therefore, the necessity of developing a biomaterial with antibacterial and wound-healing properties is paramount. Based on the special porous structure of hydrogel, we modified recombinant collagen and quaternary ammonium chitosan and fused them with silver nanoparticles (Ag@mental-organic framework (MOF)) with antibacterial properties, and asiaticoside-loaded liposomes (Lip@AS) with anti-inflammatory/vascularization effects to form the rColMA/QCSG/LIP@AS/Ag@MOF (RQLAg) hydrogel. The prepared hydrogel possessed good sustainable release capabilities of Ag+ and AS and exhibited concentration-dependent swelling properties, pore size, and compressive strength. Cellular experiments showed that the hydrogel exhibited good cell compatibility and promoted cell migration, angiogenesis, and M1 macrophage polarization. Additionally, the hydrogels exhibited excellent antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in vitro. In vivo, Sprague Dawley (SD) rats burn-wound infection model showed that the RQLAg hydrogel could efficiently promote wound healing and had stronger healing promoting abilities than those of Aquacel Ag. In summary, the RQLAg hydrogel is expected to be an excellent material for accelerating open wound healing and preventing bacterial infections. This article is protected by copyright. All rights reserved.

Pay attention to persistent inflammation-immunosuppression-catabolism syndrome in the late stage of severe burns

With the deepening of researches on organ complications after severe burns and the continuous improvement of monitoring and support technology for organ function, severe burn patients have avoided death in the early and middle to late stages due to shock, infection, etc., and entered the late stage of burns. Due to the failure of timely and effective burn wound healing and long-term exposure and infection of extensive burn wounds, some of these patients were in chronic and critical conditions such as fever, emaciation, and delayed wound healing that are accompanied by decreased immune function, anemia, and hypoproteinemia, etc. It manifested as persistent inflammation-immunosuppression-catabolism syndrome (PICS), leading to prolonged hospitalization and increased long-term mortality. Based on clinical practice of the author's team in burn treatment, this paper briefly expounds the main causes, clinical characteristics, and prevention methods of PICS in the late stage of severe burns of patients, hoping to attract the attention of peers to PICS in the late stage of severe burns.

Antibacterial and Wound Healing Activity of 2% Formulation of 2-Medpy-3-CN on Infected Burn Wounded Animal Model

Introduction: Humans have learned to recognize and process plants into medicinal forms through centuries. Burns can spread to other tissues, especially when infected with bacteria such as Methicillin-Resistant Staphylococcus aureus (MRSA). The study aimed to assess the in vivo antibacterial and wound healing activity of 2% formulation of 2-Medpy-3-CN on infected burn wounded animal model. Methods: In vitro antibacterial activity of the Alsti was done by broth dilution and disc diffusion methods. Alsti 2% ointment was prepared for the infected burn wound treatment. A total of 18 rats are grouped into A, B, C, and D, the first three groups (A-C) were injured thermally, and Group D was used as healthy controls. The three test Groups were exposed to MRSA ATCC 43300 at 105 CFU/mL. Group A was treated with 2% Alsti, Group B with Silver sulfadiazine 1% (SSD), and Group C was untreated. Wounds healing was assessed by the healed area and microscopic identification of hematoxylin and eosin (H&amp;E)-stained skin tissue. Results: Wound healing progresses with application of Alsti 2% ointment as observed through wound diameter and histopathological changes of the skin. Wound diameter decreases with treatments, while the contrary was observed in the non-treated group. Microscopic observation of the stained skin showed that epidermal development, and collagen formation progress with treatment days. Untreated wounds showed marked inflammation, progressive ulceration, and necrosis. Conclusion: Alsti 2% formulation showed antibacterial and wound healing activities, hence, can be used as alternative in burn wound infections.

764 Comparison of Topical Silver Sulfadiazine and Triple Antibiotic Ointment in a Porcine PT Burn Model

Abstract Introduction The standard of care for partial thickness burns is topical antibiotics or occlusive dressing. Silver Sulfadiazine (SSD) emerged at a time of burn wound infection and sepsis prevalence and is now the most used topical worldwide. Despite its antimicrobial benefits, SSD has been shown to inhibit keratinocytes and there is concern that it might delay wound healing. This study compared time to complete wound closure and reepithelialization in partial thickness porcine burns treated with SSD, triple antibiotics ointment or petrolatum ointment Methods We created 21 deep partial thickness (DPT) burns per animal on the backs and flanks of 3 anesthetized domesticated pigs (30-35 kg) using an established vertical progression model (aluminum bar preheated to 80° C for 20s). In each pig, burns were randomly assigned SSD, triple antibiotic ointment, or petrolatum ointment (in a 1:1:1 ratio) applied daily for two weeks followed by twice weekly for another 2 weeks. Healing progression was measured by wound digital photography and punch biopsies to assess gross wound closure, reepithelization and scar depth respectively. Results The median (IQR) days to complete wound closure were 17 (17-21), 17 (14-21), and 21 (17-21) for wounds treated with SSD, petrolatum and triple antibiotic ointment respectively (p=0.06). The mean percentage of wound reepithelization at days 10, 14, 17, 21, and 28 for wounds treated with, SSD, petrolatum, and triple antibiotic ointment were 10%±20 vs. 8%±14 vs. 3%±12 (p=0.34), 45%±49 vs. 37%±44 vs. 48%±42 (p=0.74), 82%±38 vs. 86%±20 vs. 90%±27 (p=0.7), 74%±38 vs. 65%±50 vs. 93%±16 (p=0.049), and 92%±17 vs. 91%±28 vs. 98%±5 (p=0.4). The mean scar depth was 3.9 (1.1), 4.2 (0.9), and 3.4 (0.9) mm for wounds treated with SSD, petrolatum, and triple antibiotic ointment respectively (p=0.07). RMANOVA analysis showed significant change over time (p&amp;lt; 0.001) and a near significant difference between groups (p=0.054). On macroscopic analysis, appreciable pseudoeschar formation and erythematous allergic reactions were identified on wounds treated with SSD and triple antibiotic ointment respectively. Conclusions No significant differences in wound healing were found between groups in this porcine DPT burn model. SSD did not delay closure. Hypersensitivity to topical triple antibiotics was common. Applicability of Research to Practice This study provides insight into the topical ointment standard of care for burns and helps establish the standard comparator topical treatment for future preclinical and clinical studies.

Old Wine in new Bottles: Silver Sulfadiazine Nanotherapeutics for Burn Wound Management.

According to the World Health Organization (WHO), ∼180,000 casualties are recorded every year due to burns, majorly from low- and middle-income countries that require medical attention. For the last 5 decades, silver sulfadiazine (SSD) 1% cream has been the most widely used topical antimicrobial agent for managing burn wound infections. Although SSD is considered the gold standard therapy in burn wound management, however in the last 10 years, several studies have reported the negative impact of SSD on the wound healing process. The therapeutic potential of SSD is restricted by its poor solubility, and antimicrobial action appears only after the dissociation of SSD into silver ions (Ag+) and sulfadiazine (SD). Pharmaceutical researchers and industries are looking for alternative strategies to overcome the challenges and limitations of the available SSD formulation due to rising costs, extensive time commitment, and the high risk of failure associated with the de novo development of new antimicrobial drugs. Recent advances in drug delivery systems nanotechnology-based strategies have had a colossal impact on them, particularly in burn wound management. Nanoparticulate systems and nanotools could be considered as potential drug delivery approaches for burn management. This contemporary review provides an abridgment of the literature on advanced SSD nanotherapeutics and their importance in managing burns.

Clonal relatedness of carbapenem-resistant Acinetobacter baumannii: high prevalence of ST136pas in a burn center

BackgroundCarbapenem-resistant Acinetobacter baumannii (CRAB) is a global health crisis. This study aimed to determine the clonal relatedness of antibiotic-resistant A. baumannii isolates in hospitalized patients who suffered from burn wound infection.MethodsOne hundred and six A. baumannii isolates from 562 patients with burn wound infections, were identified and examined for antimicrobial susceptibility. Detection and characterization of carbapenem-hydrolyzing class D OXA-type beta-lactamases (CHDLs) were performed by PCR assays. The clonal relatedness of A. baumannii isolates was determined by multilocus sequence typing (MLST) according to the Pasteur scheme, dual-sequence typing of blaOXA−51-like and ampC genes, and RAPD-PCR method.ResultsAll isolates were carbapenem-resistant while susceptible to colistin, minocycline, doxycycline, and ampicillin-sulbactam. The intrinsic blaOXA−51-like was detected in all isolates, and blaOXA−23-like was identified in 92.5% of isolates. However, blaOXA−143-like and blaOXA−58-like genes were not detected among isolates. Four distinct blaOXA−51-like alleles were determined as follows: blaOXA−317 (67.0%), blaOXA−90 (9.4%), blaOXA−69 (17.0%), and blaOXA−64 (6.6%) and four ampC (blaADC) allele types including ampC-25 (6.6%), ampC-39 (9.4%), ampC-1 (17.0%), and blaADC−88 (67.0%) were identified. MLST (Pasteur scheme) analysis revealed four ST types including ST136 (singleton), ST1 (CC1), ST25 (CC25), and ST78 (singleton) in 71, 18, 7, and 10 of A. baumannii strains, respectively. Five RAPD clusters including A (1.9%), B (26.4%), C (57.5%), D (7.5%), and E (1.9%) were characterized and 5 (4.7%) strains were found to be singletons.ConclusionThe present study demonstrated that there was a high prevalence of blaOXA−23-like producing CRAB in the clinical setting. The majority of isolates belonged to ST136 (singleton). However, blaOXA−23-like producing multi-drug resistant international clones including ST1, and emerging lineages (e.g. ST25 and ST78) were also identified. Interestingly, in this study ST2 was not detected.

Evaluation of biogenic nanosilver-acticoat for wound healing: A tri-modal in silico, in vitro and in vivo study

Wound healing is a complex process that involves numerous biological and physiological events and is influenced by various local and systemic factors. Chronic wounds affect around 6 million people and pose a significant clinical challenge for healthcare professionals, particularly in light of the increasing difficulty in treating wound infections with conventional antibiotics. Conventional wound dressings have several limitations, including insufficient antibacterial potency, toxicity, failure to deliver adequate moisture to the wound, and poor mechanical properties. Silver nanoparticles (AgNPs) have shown great promise in wound healing due to their exceptional antibacterial properties. In this study, AgNPs were synthesized via green synthesis using Camellia sinensis and Ocimum sanctum and characterized by various techniques. The AgNPs were incorporated into carrageenan to develop nanosilver acticoat for wound healing applications. The anti-bacterial property of the acticoat was tested against S. aureus and E. coli bacteria, and in vivo studies showed that dressing with Carrageenan silver nanoparticles (CAgNPs) acticoat promoted wound healing and had good reepithelialization and dense collagen deposition capabilities. With a significance level of < 0.05, we used one-way ANOVA to analyze the means between groups. In silico analysis with pkCSM and SwissADME provided information on the drug-likeness and human health hazard-related predictions for the prepared formulations. The study highlights the potential of the prepared CAgNPs acticoat for dressing applications in the burn, accidental, and diabetic wound infections. These results suggest that the use of CAgNPs acticoat can provide a safe and effective alternative to conventional wound dressings in promoting wound healing.

Comparative Study of the Antibacterial Activity of Algerian Honeys and Manuka Honey Toward Pathogenic Bacteria from Burn Wound Infections

Objective. Honey is an extremely promising agent in the treatment of infected wounds of burned patients. This study aims to evaluate the antibacterial activity of 14 Algerian honey samples in comparison to Manuka honey towards pathogenic bacteria isolated from burn wound infections. Methods. The antibacterial effect of 14 Algerian honey samples and the Manuka honey was assessed against six multidrug-resistant bacteria: Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, Staphylococcus saprophyticus, and Enterococcus faecalis. Well agar diffusion, microdilution broth assay, and time-kill assay were used to evaluate the effects of honey samples on the growth of pathogenic bacteria. Results. The results obtained show that all tested honey samples have good antibacterial effects and there is no significant difference between Algerian honey samples and Manuka honey, except honey samples H12 and H13. The Gram-positive bacteria were more susceptible to honey samples than Gram-negative bacteria. The inhibitory diameters were between 14 to 38 mm for Gram-positive bacteria and from 8 to 28 mm for Gram-negative bacteria. The minimal inhibitory concentration of Algerian honey was between 5 and 80% (v/v) and minimal bactericidal concentration was between 10 and 80 % (v/v). However, the minimal inhibitory concentration of Manuka honey was between 5 and 40% (v/v) and minimal bactericidal concentration was between 10 and 80% (v/v). The MBC/MIC ratio was from 1 to 2, which proves that both Algeria honeys and Manuka honey have a bactericidal effect rather than a bacteriostatic effect. A time-kill assay showed that the inhibition effect of honey samples started after the first 3 hours of incubation. Honey samples 3 and 7 inhibited the growth of S. aureus and S. saprophyticus in 15 hours; however, they inhibited the growth of the other pathogenic bacteria in 18 hours. Conclusions. This study proposes honey as an extremely promising treatment against multidrug-resistant bacteria from burn infections.