The Antibacterial Activity of Acetic Acid against Biofilm-Producing Pathogens of Relevance to Burns Patients

In Vitro Assessment of Salivary Pellicle Disruption and Biofilm Removal on Titanium: Exploring the Role of Surface Hydrophobicity in Chemical Disinfection

OBJECTIVES

Peri-implantitis is mostly caused by a pathological biofilm that forms through complex processes, initiated by the formation of the salivary pellicle on implant surfaces. Understanding the nature of these pellicles and biofilm and how to remove them is important for preventing peri-implant infections and improving the success of dental implants. This study explores the characteristics of the salivary pellicle on titanium surfaces and assesses the effectiveness of different decontamination agents in eliminating the salivary pellicle and related microbial contaminations.

MATERIALS AND METHODS

Titanium surfaces were contaminated with salivary pellicles and pathological biofilms. The nature of the salivary pellicle was characterized using X-ray photoelectron spectroscopy (XPS), surface proteomics, contact angle measurements, and fluorescence microscopy. We tested six commonly used decontamination chemicals (chlorhexidine, essential oil-based mouthwash, citric acid, phosphoric acid, saline, and phosphate buffer saline) as well as newly proposed treatments such as surfactants and solvents (acetone, acetic acid, and Tween 20) for their capability to eliminate salivary pellicles and pathogenic biofilms from titanium surfaces.

RESULTS

The hydrophobic nature of the salivary pellicle on titanium surfaces limits the efficacy of commonly used hydrophilic solutions in removing pellicles and bacteria. Organic solvents and surfactants, particularly acetic acid and Tween 20, demonstrated superior effectiveness in removing the pellicle and biofilm. Acetic acid was notably effective in restoring surface composition, reducing microbial levels, and removing multispecies biofilms.

CONCLUSIONS

The use of surfactants and solvents could be a promising alternative for the treatment of biofilms on titanium surfaces. However, further studies are needed to explore their clinical applicability.

Advances in Orthopedic Surgery Irrigation: A Review of Traditional Agents and the Emergence of Citrate-Based Solutions

Surgical site infections (SSIs) and prosthetic joint infections (PJIs) remain significant challenges in orthopedic surgery, particularly in joint arthroplasty. Intraoperative irrigation is a widely used strategy for infection prevention, yet traditional solutions such as saline, povidone-iodine, hydrogen peroxide, and sodium hypochlorite are limited by cytotoxicity, short antimicrobial duration, and poor biofilm penetration. This review evaluates commonly used irrigation agents and highlights the growing evidence supporting a novel citrate-based solution as a potentially superior alternative. These agents combine broad-spectrum antimicrobial activity, effective biofilm disruption through ionic chelation, and prolonged postoperative protection with minimal harm to host tissues. Early clinical studies and ongoing randomized trials have demonstrated promising results, including reductions in postoperative swelling, opioid use, and infection rates. As more data become available, citrate-based solutions may emerge as the preferred standard for intraoperative irrigation in orthopedic procedures.

Profiling of Metabolite Changes in Lettuce Leaves during Fermentation by Bacillus subtilis

Metabolic profiling is a valuable tool for elucidating the biochemical pathways and key metabolites involved in the health benefits associated with microbial fermentation. In this study, we investigated the metabolic changes occurring during the fermentation of lettuce leaves by Bacillus subtilis, a widely studied bacterium known for its diverse metabolic capabilities. Through non-targeted metabolic profiling, we identified and characterized metabolites that may contribute to the beneficial effects of fermented lettuce. Using gas chromatography-mass spectrometry (GC/MS), we identified 54 metabolites in the fermented lettuce samples. Additionally, we elucidated the alterations in metabolite profiles during the bioconversion of lettuce using B. subtilis. Notably, 11,14-eicosadienoic acid, 13-docosenoic acid, and oleic acid were either produced or enriched during bioconversion, were identified as potential contributors to the enhanced nutritional and bioactive properties of fermented lettuce. This study underscores the potential of metabolic profiling to uncover the metabolic pathways and specific metabolites associated with health benefits in fermented foods. These findings pave the way for developing functional foods with improved nutritional value and bioactivity.

Evaluation of the Antibacterial Activity of Acetic Acid in Comparison With Three Disinfectants Against Bacteria Isolated From Hospital High-Touch Surfaces

Acetic acid, a readily available and less toxic alternative to conventional disinfectants, is widely used for cleaning in household settings. This study evaluates the antibacterial efficacy of acetic acid against bacteria isolated from hospital high-touch surfaces, comparing its performance to commonly used disinfectants, including phenol, sodium hypochlorite, and didecyldimethylammonium chloride (DDAC). A total of 120 samples were collected from high-touch surfaces in specialized patient areas. The antibacterial activity of acetic acid, phenol, sodium hypochlorite, and DDAC was assessed using the standard broth microdilution method against the isolated bacterial strains. From the 120 samples, 140 bacterial isolates were obtained. Acetic acid demonstrated strong antibacterial activity, with mean minimum inhibitory concentrations (MICs) ranging from 0.05 ± 0.00 to 0.25 ± 0.06 μL/mL, effectively inhibiting coagulase-negative Staphylococcus (CONS), Klebsiella pneumoniae, Proteus vulgaris, Enterococcus species, and Serratia marcescens. Its performance surpassed phenol and DDAC against these strains. Phenol exhibited higher MICs (0.50 ± 0.00 to 0.83 ± 0.10 μL/mL), indicating lower efficacy, while DDAC (0.06 ± 0.00 to 0.17 ± 0.04 μL/mL) and sodium hypochlorite (0.06 ± 0.00 to 0.10 ± 0.00 μL/mL) demonstrated comparable antibacterial effects. Phenol and sodium hypochlorite were found nonsignificant, while DDAC is highly effective at a concentration of 8.5%. Hospital surfaces were found to be contaminated with diverse bacterial strains. Acetic acid demonstrated significant antibacterial efficacy against both gram-positive and gram-negative bacteria, with MICs ranging from 0.05 ± 0.00 to 0.25 ± 0.06 μL/mL, suggesting its potential as an effective, economical, and less toxic alternative to conventional disinfectants.

Pseudomonas aeruginosa in Chronic Suppurative Otitis Media

BACKGROUND

Chronic suppurative otitis media (CSOM) has caused many hearing disorder cases in developing countries. Inappropriate antibiotic use resulted in a shift of bacterial resistance. The biofilm-forming bacteria, like Pseudomonas aeruginosa, was a common germ detected in CSOM that contributed to a poor prognosis. This study aimed to investigate the bacterial pattern from samples taken from CSOM patients regarding its antibiotic susceptibility and the antibiofilm activity of acetic acid against P. aeruginosa.

MATERIALS AND METHODS

Sterile swabs of forty-five patients with CSOM were collected, followed by isolation of bacterial pathogens, identification, and evaluation of antibiotic sensitivity using modified Kirby Bauer disc diffusion protocol. In vitro testing was done by adding acetic acid to P. aeruginosa culture to gauge the minimum concentration of biofilm inhibition and eradication. They were conducted using the microtiter plate assay method and quantified with an ELISA reader. The data were analyzed statistically using One-Way ANOVA and Tukey Honestly Significant Difference post hoc test.

RESULTS

The samples obtained from 31 of 45 CSOM patients showed positive microbial growth; 26 (57.78%) had a monomicrobial pattern, and 5 (11.11%) had a polymicrobial pattern. The researcher ascertained that 24 isolates, representing 66.67%, were gram-negative bacteria, with P.-aeruginosa identified as the predominant species. P. aeruginosa isolates were sensitive to several antibiotics, including meropenem, amikacin, piperacillin-tazobactam, ceftazidime, and cefoperazone-sulbactam with a rate of 93.33%. The minimum concentration of acetic acid required to qualify as the minimum biofilm inhibitory concentration (MBIC) was determined to be 0.16%, yielding an inhibition rate of 26.79%. A concentration of 0.31% was identified as the minimum biofilm eradication concentration (MBEC), achieving an eradication rate of 77.27%.

CONCLUSION

P. aeruginosa, the most common bacteria found in CSOM samples, was sensitive to imipenem, amikacin, piperacillin-tazobactam, ceftazidime, and cefoperazone-sulbactam. Acetic acid suppresses P. aeruginosa bacterial biofilm formation at MBIC of 0.16% and MBEC of 0.31%.

Comprehensive genomics, probiotic, and antibiofilm potential analysis of Streptococcus thermophilus strains isolated from homemade and commercial dahi

This study investigated the probiotic properties and antibiofilm potential of Streptococcus thermophilus strains obtained from homemade and commercial dahi. The S. thermophilus strain from homemade dahi had greater acid tolerance than the commercial strain, indicating a greater capacity to live in the acidic environments of the stomach. The commercial strain had increased survivability in bile salts and was more hydrophobic than the homemade strain. These findings suggest improved adaptability and increased colonization in the gut. The genomes of both strains included genes associated with probiotic characteristics implying that the two strains may provide unique probiotic advantages. These findings highlight the importance of cell-free supernatants (CFS) of these strains in reducing biofilm formation of pathogenic bacteria. Gas chromatography-mass spectrometry demonstrated that 2, 4-di-tert-butylphenol was a shared metabolite in the CFSs of both strains; however, 2-butanol was found only in the CFS of the homemade dahi strain. In-silico investigations revealed that compounds have drug-like characteristics, suggesting that they could be used for treating biofilm-associated diseases. This study highlights the health advantages of probiotics found in traditional dahi, but it also provides a way to develop natural antibacterial medicines.

The efficacy and safety of acids as topical antimicrobial agents: a review

OBJECTIVE

Infected wounds, refractory to conventional therapy, are a major burden on the healthcare system. Available data show that many commonly used antiseptic agents may be toxic to the cells involved in the healing process and may affect the normal tissue repair. The topical use of different acids to control wound infections effectively and promote healing is well known. The present review aims to summarise the safety and efficacy of various acids as topical agents for treating wound infections.

METHOD

A literature search was performed in PubMed and manually from other sources (cross references and journal sites).

RESULTS

We reviewed 116 articles, from which data from 86 relevant articles were analysed. The studies showed that various organic acids were clinically effective in treating wound infections.

CONCLUSION

This study found that various organic acids can act as a substitute for antiseptics to control wound infections refractory to conventional antibiotic therapy and local wound care. Various organic acids differ in efficacy, safety and limitations as topical agents to control wound infections and promote healing. Some acids deliver better results than others, particularly in those cases in which antibiotics and routine antiseptic agents yield little lasting success, especially in controlling hospital strains with multiple antibiotic resistance. Among topically used acids, citric acid and acetic acid are associated with better results.

Efficacy of Adjunctive Antiseptic Lavage Solution in Managing Acute Hip/Knee Prosthetic Joint Infection: A Comparative Study in a Tertiary Revision Center

Background

Debridement, antibiotics and implant retention (DAIR) procedure is well-established as a management option for acute periprosthetic joint infection (PJI). We investigated the infection eradication rates of DAIR procedures at our center using Bactisure wound lavage.

Methods

A retrospective consecutive review of DAIR procedures for hip and knee PJI was conducted between 2018 and 2023 with a minimum 12-month follow-up at our tertiary revision arthroplasty center. Suitability for DAIR was determined at the multi-disciplinary team discussion. Revision procedures and patients with previous PJI were excluded. Patient, surgical, microbiological, and postoperative data (minimum 12 months) was reviewed. The use of Bactisure was in addition to routine surgical management.

Results

During the study period, 76 DAIR procedures were performed (55 knees and 21 hips). Bactisure was used in 26 cases (20 knees and 6 hips). Overall, 6 of 26 Bactisure DAIRs failed (23%), while 14 of 50 non-Bactisure DAIRs failed (28%), which did not demonstrate statistical significance (P = .644). Subgroup analysis demonstrated no difference in knee DAIRs (P = .761) but a trend toward significance in hip DAIRs (P = .262). No adverse effects of Bactisure use were noted intraoperatively or postoperatively. DAIR failed in 50% of diabetic patients compared to 20% of nondiabetic patients (P = .015). Age, body mass index, and organism identification did not influence outcome.

Conclusions

The addition of Bactisure to DAIR procedures did not demonstrate statistically significant improvement of successful eradication of infection, but a potential trend toward significance was noted in hip DAIRs. Diabetic patients failed DAIR in 50% of cases. The in-vivo outcomes of Bactisure use during DAIR procedures remain inconclusive.

Production of probiotic bacterial cellulose with improved yield, mechanical properties, and antibacterial activity from cost-effective coculture and mixed-culture fermentation in coconut water by Komagataeibacter xylinus MSKU 12

We successfully enhanced bacterial cellulose (BC) production in low-cost coconut water (CW) at 37 °C by low-nutrient adaptation of Komagataeibacter xylinus MSKU 12. In this study, the BC yield was significantly increased by simultaneous coculture fermentation of MSKU 12 with Saccharomyces bayanus in Hestrin-Schramm (HS) and CW media. Coculture fermentation at 30 °C produced BC yields of 13.44 and 12.13 g/L dry weight in HS containing 0.5 % acetic acid, 3 % sucrose, and 0.5 % ammonium sulfate (HS0.5A3S0.5N) after 9 days of incubation and in CW containing 0.5 % acetic acid, 3 % sucrose, and 0.5 % ammonium sulfate (CW0.5A3S0.5N) after 12 days of incubation. Moreover, at 37 °C, relatively high amounts of BC (8.64 and 7.89 g/L dry weight) were obtained from coculture in HS0.5A3S0.5N and CW0.5A3S0.5N, respectively, after 12 days of cultivation. Coculture fermentation not only increased the BC yield but also altered the properties of BC, resulting in finer microfibrils, higher mechanical strength, and stronger antibacterial activities. Both fresh and freeze-dried probiotic BC from the simultaneous mixed-culture fermentation of MSKU 12, S. bayanus, and Pediococcus pentosaceus DMKU 14-7 exhibited strong inhibitory effects against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. These results provided insights into the development of biopreservatives against foodborne pathogens.

Simultaneous viscoelasticity and sprayability in antimicrobial acetic acid-alginate fluid gels

Acetic acid is a promising alternative to antibiotics for topical applications, particularly burn wounds, however its site specificity and retention are impaired by poor material properties. In this study, acetic acid was investigated as both the gelling agent and antimicrobial active in alginate fluid gels. The formed microstructure was found to be directly dependent on acetic acid concentration, leading to highly tuneable material properties. At clinically relevant concentrations of 2.5-5 % acetic acid, the fluid gels were elastically dominated at rest, with viscosities up to 7 orders of magnitude greater than acetic acid alone. These material properties imparted long term surface retention and microparticle barrier function, not seen with either acetic acid or alginate solutions. Most notably, sprayability was enhanced simultaneously with the increased viscosity and elasticity due to the introduction of a discretised microstructure, leading to a remarkable tenfold increase in spray coverage. Formulation was found not to inhibit antimicrobial activity, despite the less acidic pH, with common burn wound pathogens Staphylococcus aureus and Pseudomonas aeruginosa being equally susceptible to the fluid gels as to acetic acid solutions.

Next generation sequencing identifies an increased diversity of microbes in post lavage specimens in infected TKA using a biofilm disrupting irrigant

BACKGROUND

Periprosthetic joint infection (PJI) is a devastating complication of joint arthroplasty. In chronic PJI, a biofilm envelops the surface of implants, which contains microbiota within an extra-microbial polymeric matrix (EMPM). Microbial identification is paramount for effective treatment. In this study, we use a multi-modal, EMPM disrupting, neoadjuvant irrigant and compare the microbiota detected pre-lavage to post-lavage by two techniques: culture and Next Generation Sequencing (NGS). We suspect more organisms to be identified after applying an EMPM disrupting irrigant.

METHODS

A multicenter, prospective study was conducted on 38 patients with known Total Knee Arthroplasty PJI. At initial arthrotomy, synovial fluid was obtained and analyzed for quantitative cultures and microbial NGS. Joint was then irrigated with Bactisure Lavage followed by Normal Saline. Post-lavage samples were similarly obtained and analyzed.

RESULTS

In pre-lavage samples for cultures, 55.3% of samples were positive, identifying 11 unique organisms. In post-lavage samples for cultures, 13.2% of samples were positive, identifying 5 unique organisms. In pre-lavage samples for NGS, 79% were DNA signal positive, identifying 126 unique organisms. In post-lavage samples for NGS, 74% of samples were DNA signal positive, identifying 177 unique organisms. Moreover, 135/177 of these organisms were not identified pre-lavage.

CONCLUSION

In this pre-to-post irrigant study, culture showed a decrease in the number of identifiable organisms post-lavage. In contrast NGS revealed an increase in the number of identifiable organisms post-lavage. Furthermore, NGS identified 135 additional organisms, not detected pre-lavage. This suggests an increased diversity of microbes may exist within EMPM, which are not cultivable.

Development of active films with thymol-based hydrophobic eutectic solvents

Thymol, known for its antimicrobial properties, was combined with acetic acid, betaine, and caprylic acid to form hydrophobic natural eutectic solvents (NAES), whose influence on the properties of bovine gelatin films was investigated. Films showed enhanced mechanical performance and a clear plasticizing effect provided by the natural eutectic solvents. At 300 wt% concentration, tensile strength and elongation at break reached 871 ± 78 kPa and 141 ± 10 % for acetic acid, 391 ± 41 kPa and 159 ± 10 % for betaine, and 1209 ± 52 kPa and 198 ± 15 % for caprylic acid. Water vapor permeability and total soluble matter were reduced, and swelling decreased to ~250 %, ~150 %, and ~ 200 % for films with 300 wt% of acetic acid, betaine, and caprylic acid, respectively. Pure thymol exhibited significant volatility, with 17.10 ± 1.50 % weight loss over one week, while the NADES demonstrated dramatically reduced losses (up to 1.15 ± 0.04 %). The films displayed exceptional antibacterial activity, achieving inhibition diameters of 34 mm against Gram-positive and Gram-negative bacteria, and films with caprylic or acetic NAES achieved undetectable CFU levels for major pathogens on chicken breast. These results highlight the antimicrobial potency and enhanced stability of NAES-based gelatin films for active packaging applications.

Pot-Pollen Volatiles, Bioactivity, Synergism with Antibiotics, and Bibliometrics Overview, Including Direct Injection in Food Flavor

Stingless bees (Hymenoptera; Apidae; Meliponini), with a biodiversity of 605 species, harvest and transport corbicula pollen to the nest, like Apis mellifera, but process and store the pollen in cerumen pots instead of beeswax combs. Therefore, the meliponine pollen processed in the nest was named pot-pollen instead of bee bread. Pot-pollen has nutraceutical properties for bees and humans; it is a natural medicinal food supplement with applications in health, food science, and technology, and pharmaceutical developments are promising. Demonstrated synergism between Tetragonisca angustula pot-pollen ethanolic extracts, and antibiotics against extensively drug-resistant (XDR) bacteria revealed potential to combat antimicrobial resistance (AMR). Reviewed pot-pollen VOC richness was compared between Australian Austroplebeia australis (27), Tetragonula carbonaria (31), and Tetragonula hogkingsi (28), as well as the Venezuelan Tetragonisca angustula (95). Bioactivity and olfactory attributes of the most abundant VOCs were revisited. Bibliometric analyses with the Scopus database were planned for two unrelated topics in the literature for potential scientific advances. The top ten most prolific authors, institutions, countries, funding sponsors, and sources engaged to disseminate original research and reviews on pot-pollen (2014-2023) and direct injection food flavor (1976-2023) were ranked. Selected metrics and plots were visualized using the Bibliometrix-R package. A scholarly approach gained scientific insight into the interaction between an ancient fermented medicinal pot-pollen and a powerful bioanalytical technique for fermented products, which should attract interest from research teams for joint projects on direct injection in pot-pollen flavor, and proposals on stingless bee nest materials. Novel anti-antimicrobial-resistant agents and synergism with conventional antibiotics can fill the gap in the emerging potential to overcome antimicrobial resistance.

Antimelanogenic and Antioxidant Effects of Postbioics of Lactobacillus Strains in α-MSH-Induced B16F10 Melanoma Cells via CREB/MITF and MAPKs Signaling Pathway

Abnormal melanin synthesis can lead to severe skin problems. This study investigated the anti-melanogenic effects on α-melanocyte stimulating hormone (α-MSH)-induced B16F10 cells using cell-free supernatants of Lactiplantibacillus plantarum WB326 and Levilactobacillus brevis WB2810. Samples were prepared using 1 mg/ml freeze-dried culture supernatant. Cell viability was assessed using B16F10 cells and MTT assay. Tyrosinase inhibition and melanin content decreased in the samples compared to those treated with α-MSH. This effect was also observed when L-DOPA staining was used under a microscope. Moreover, the mRNA expression levels of microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 decreased in the sample-treated group. Protein expression of the CREB/MITF/MAPK signaling pathway was also reduced. Using HPLC analysis, lactic and acetic acids were detected in the culture supernatants. Finally, the antioxidant effects of the samples were confirmed by comparison with those of Trolox and arbutin. According to the experimental results, their utilization is possible in the fields of functional materials and cosmetic ingredients.

The Acid-Buffered Engineered Gel Promotes In Vitro Cutaneous Healing and Fights Resistant Bacteria in Wounds

Background: Treatment of cutaneous wound infections is becoming a major clinical challenge due to the growing problem of antimicrobial resistance associated with existing wound treatments. Two prevalent pathogens in wound infections, Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa), continue to present a serious challenge, underscoring the critical need for new therapeutic alternatives. Methods: Novel alginate acid-buffered gels (ABF-1, ABF-2, and ABF-3) were developed using a combination of organic acids in various concentrations and buffered at a pH of 4.5. The acid-buffering capacity of the gels was evaluated against sodium hydroxide solution and simulated wound fluid (SWF) at different wound pHs, mimicking infected and non-infected wound environments. The in vitro antibacterial activity was assessed against resistant bacterial strains (Gram-positive and Gram-negative) using a microdilution method and wound biofilm assay. The rheological properties and cell viability of the gels were evaluated and the gel showing positive cell viability was further investigated for healing ability using an in vitro wound scratch assay. Results: The gels showed promising in vitro antibacterial activity against Staphylococcus epidermidis, S. aureus, and P. aeruginosa. Gels with higher acid concentrations (ABF-1 and ABF-2) were highly effective in reducing the bacterial load in chronic biofilms of S. aureus and P. aeruginosa, while the gel with a lower acid concentration (ABF-3) showed positive effects on the viability of skin cells (over 80% cells viable) and for promoting wound closure. All three gels demonstrated excellent acid-buffering capabilities. Conclusions: The acid-buffered gels demonstrate promising in vitro antibacterial effects, indicating their potential for enhancing wound healing.

Camellia sinensis methanolic leaves extract: Phytochemical analysis and anticancer activity against human liver cancer cells

BACKGROUND

The study's primary goal is to ascertain whether there is a relationship between the processed green tea methanolic extract's (GTME) phytochemical components and its potential effectiveness against human liver cancer cells. The GTME's phytochemical composition was identified using gas chromatography-mass spectrometry, and the extract's capacity to lower cellular proliferation and cause apoptosis in HepG2 cancerous liver cell lines was checked.

RESULTS

The findings of the gas chromatography-mass chromatogram showed that GTME included bioactive antioxidants and anticancer substances. Additionally, utilizing the MTT, comet assay, and acridine assay, GTME revealed a selective cytotoxic impact with a significant IC50 value (27.3 µg/ml) on HepG2 cells without any harmful effects on WI-38 healthy cells. Also, compared to untreated cells, the extract-treated HepG2 cells had an upsurge in the proportion of cells that have undergone apoptosis and displayed a comet nucleus, which is a sign of DNA damage. In addition, HepG2 cells treated with GTME revealed a stop in the G1 phase and sub-G1 apoptotic cells (37.32%) in a flow cytometry analysis. Furthermore, reactive oxygen species were shown to be responsible for HepG2 apoptosis, and the tested extract significantly reduced their levels in the treated cells. Lastly, compared to untreated cells in treated HepG2 cells, GTME significantly changed protein expression levels linked with cell cycle arrest in the G1 phase and apoptosis.

CONCLUSION

These findings provided information about the processes through which the GTME inhibited the growth of HepG2. Therefore, it has potential as an effective natural therapy for the treatment of human liver cancer. However, to validate these findings, animal models must be used for in vivo studies.

Antimicrobial Impact of Wood Vinegar Produced Through Co-Pyrolysis of Eucalyptus Wood and Aromatic Herbs

BACKGROUND

The search for substances that can overcome microorganisms' resistance and enhance the antimicrobial activity of given products has attracted the attention of researchers. Eucalyptus wood vinegar (WV) is a promising product for developing alternative antimicrobials.

OBJECTIVES

This study aimed to evaluate whether the production of WV in the co-pyrolysis of eucalyptus wood with aromatic herbs would incorporate compounds from them into WV and if that would enhance its antimicrobial action.

METHODOLOGY

WV was produced alone and through co-pyrolysis with marjoram (Origanum majorana), Peruvian oregano (Origanum vulgare), rosemary (Salvia rosmarinus), thyme (Thymus vulgaris), and Turkish oregano (Origanum onites) at a proportion of 25% of herbs to the bone-dry wood weight. The antimicrobial effects were assessed against strains of gram-negative and -positive bacteria, and Candida glabrata. Microorganisms' colony growth in agar had their absorbances recorded after inoculation and incubation. Chemical characterization of the new products was performed by gas chromatography and mass spectrometry (GC/MS).

RESULTS

After coproduction, there were relevant chemical changes concerning the original WV. Thymol, for instance, was incorporated into the WV through co-pyrolysis with marjoram, Peruvian and Turkish oregano, and thyme. The coproducts were more efficient than the WV produced only with wood, with thyme-incorporated products having the highest efficiency. This can be attributed to the increase and incorporation of the substances after coproduction, and particularly the role of thymol in enhancing the antimicrobial action.

CONCLUSION

Given the results, the co-production of WV with eucalyptus wood and aromatic herbs has the potential to provide alternative antimicrobial products.

Effect of Acetic Acid on Biofilm Formation in Paracidovorax citrulli, Causal Agent of Bacterial Fruit Blotch

The unique tissue structure of pathogenic bacteria biofilm plays an important role in its pathogenicity and bactericide resistance. Inhibition or destruction of biofilm formation of pathogenic bacteria is of great significance for the control of plant bacterial diseases. In this study, Paracidovorax citrulli was inoculated into KB medium containing acetic acid, and after shaking at 28°C and 55 r/min for 48 h, it was found that the content of extracellular polysaccharide, extracellular protein and extracellular DNA (eDNA) decreased with the increase of acetic acid concentration, which resulted in the decrease of biofilm formation, it is not even possible to form biofilms on plastic slides. When the final concentration of acetic acid in the culture medium was greater than or equal to 0.5 mg/mL, there was no biofilm on the plastic slides. Therefore, the use of acetic acid as an inhibitor of P. citrulli has a good potential for control of bacterial fruit blotch.

Pathogens in FRI - Do bugs matter? - An analysis of FRI studies to assess your enemy

Fracture-related infection (FRI) is a devasting complication for both patients and their treating Orthopaedic surgeon that can lead to loss of limb function or even amputation. The unique and unpredictable features of FRI make its diagnosis and treatment a significant challenge. It has substantial morbidity and financial implications for patients, their families and healthcare providers. In this article, we perform an in-depth and comprehensive review of FRI through recent and seminal literature to highlight evolving definitions, diagnostic and treatment approaches, focusing on common pathogens such as Staphylococcus aureus, polymicrobial infections and multi-drug-resistant organisms (MDRO). Furthermore, multiple resistance mechanisms and adaptations for microbial survival are discussed, as well as modern evidence-based medical and surgical advancements in treatment strategies in combating FRI.

Prevention and Management of Wound Infections in Burn Patients

The leading cause of morbidity in burn patients is infection with pneumonia, urinary tract infection, cellulitis, and wound infection being the most common cause. High mortality is due to the immunocompromised status of patients and abundance of multidrug-resistant organisms in burn units. Despite the criteria set forth by American Association of Burn, the diagnosis and treatment of burn infections are not always straightforward. Topical antimicrobials, isolation, hygiene, and personal protective equipment are common preventive measures. Additionally medical and nutritional optimization of the patients is crucial to reverse the immunocompromised status triggered by burn injury.

Bactericidal Efficacy of the Combination of Maresin-like Proresolving Mediators and Carbenicillin Action on Biofilm-Forming Burn Trauma Infection-Related Bacteria

Biofilm-associated bacterial infections are the major reason for treatment failure in many diseases including burn trauma infections. Uncontrolled inflammation induced by bacteria leads to materiality, tissue damage, and chronic diseases. Specialized proresolving mediators (SPMs), including maresin-like lipid mediators (MarLs), are enzymatically biosynthesized from omega-3 essential long-chain polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), by macrophages and other leukocytes. SPMs exhibit strong inflammation-resolving activities, especially inflammation provoked by bacterial infection. In this study, we explored the potential direct inhibitory activities of three MarLs on Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria in their biofilms that are leading bacteria in burn trauma-related infections. We also examined the effects of MarLs on the bactericidal activities of a typical broad-spectrum antibiotic, carbenicillin (carb), on these bacteria in their preformed biofilms. The results revealed that MarLs combined with carbenicillin can inhibit the survival of Gram-positive and Gram-negative bacteria in their biofilms although MarLs alone did not exhibit bactericidal activity. Thus, our findings suggest that the combination of MarLs and carbenicillin can lower the antibiotic requirements to kill the bacteria in preformed biofilms.

Exploitation of microbial activities at low pH to enhance planetary health

Awareness is growing that human health cannot be considered in isolation but is inextricably woven with the health of the environment in which we live. It is, however, under-recognized that the sustainability of human activities strongly relies on preserving the equilibrium of the microbial communities living in/on/around us. Microbial metabolic activities are instrumental for production, functionalization, processing, and preservation of food. For circular economy, microbial metabolism would be exploited to produce building blocks for the chemical industry, to achieve effective crop protection, agri-food waste revalorization, or biofuel production, as well as in bioremediation and bioaugmentation of contaminated areas. Low pH is undoubtedly a key physical-chemical parameter that needs to be considered for exploiting the powerful microbial metabolic arsenal. Deviation from optimal pH conditions has profound effects on shaping the microbial communities responsible for carrying out essential processes. Furthermore, novel strategies to combat contaminations and infections by pathogens rely on microbial-derived acidic molecules that suppress/inhibit their growth. Herein, we present the state-of-the-art of the knowledge on the impact of acidic pH in many applied areas and how this knowledge can guide us to use the immense arsenal of microbial metabolic activities for their more impactful exploitation in a Planetary Health perspective.

Apple cider vinegar exhibits promising antibiofilm activity against multidrug-resistant Bacillus cereus isolated from meat and their products

Background

Bacillus cereus (B. cereus) biofilm is grown not only on medical devices but also on different substrata and is considered a potential hazard in the food industry. Quorum sensing plays a serious role in the synthesis of biofilm with its surrounding extracellular matrix enabling irreversible connection of the bacteria.

Aim

The goal of the current investigation was to ascertain the prevalence, patterns of antimicrobial resistance, and capacity for B. cereus biofilm formation in meat and meat products in Egypt.

Methods

In all, 150 meat and meat product samples were used in this study. For additional bacteriological analysis, the samples were moved to the Bacteriology Laboratory. Thereafter, the antimicrobial, antiquorum sensing, and antibiofilm potential of apple cider vinegar (ACV) on B. cereus were evaluated.

Results

Out of 150 samples, 34 (22.67%) tested positive for B. cereus. According to tests for antimicrobial susceptibility, every B. cereus isolates tested positive for colistin and ampicillin but negative for ciprofloxacin and imipenem. The ability to form biofilms was present in all 12 multidrug-resistant B. cereus isolates (n = 12); of these, 6 (50%), 3 (25%), and 3 (25%) isolates were weak, moderate, and strong biofilm producers, respectively. It is noteworthy that the ACV demonstrated significant inhibitory effects on B. cereus isolates, with minimum inhibitory concentrations varying between 2 and 8 μg/ml. Furthermore, after exposing biofilm-producing B. cereus isolates to the minimum biofilm inhibitory concentrations 50 of 4 μg/ml, it demonstrated good antibiofilm activity (>50% reduction of biofilm formation). Strong biofilm producers had down-regulated biofilm genes (tasA and sipW) and their regulator (plcR) compared to the control group, according to reverse transcriptase quantitative polymerase chain reaction analysis.

Conclusion

Our study is the first report, that spotlights the ACV activity against B. cereus biofilm and its consequence as a strong antibacterial and antibiofilm agent in the food industry and human health risk.

Bioactive-Loaded Hydrogels Based on Bacterial Nanocellulose, Chitosan, and Poloxamer for Rebalancing Vaginal Microbiota

Biocompatible drug-delivery systems for soft tissue applications are of high interest for the medical and pharmaceutical fields. The subject of this research is the development of hydrogels loaded with bioactive compounds (inulin, thyme essential oil, hydro-glycero-alcoholic extract of Vitis vinifera, Opuntia ficus-indica powder, lactic acid, citric acid) in order to support the vaginal microbiota homeostasis. The nanofibrillar phyto-hydrogel systems developed using the biocompatible polymers chitosan (CS), never-dried bacterial nanocellulose (NDBNC), and Poloxamer 407 (PX) incorporated the water-soluble bioactive components in the NDBNC hydrophilic fraction and the hydrophobic components in the hydrophobic core of the PX fraction. Two NDBNC-PX hydrogels and one NDBNC-PX-CS hydrogel were structurally and physical-chemically characterized using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and rheology. The hydrogels were also evaluated in terms of thermo-responsive properties, mucoadhesion, biocompatibility, and prebiotic and antimicrobial effects. The mucin binding efficiency of hydrogel base systems was determined by the periodic acid/Schiff base (PAS) assay. Biocompatibility of hydrogel systems was determined by the MTT test using mouse fibroblasts. The prebiotic activity was determined using the probiotic strains Limosilactobacillus reuteri and Lactiplantibacillus plantarum subsp. plantarum. Antimicrobial activity was also assessed using relevant microbial strains, respectively, E. coli and C. albicans. TEM evidenced PX micelles of around 20 nm on NDBNC nanofibrils. The FTIR and XRD analyses revealed that the binary hydrogels are dominated by PX signals, and that the ternary hydrogel is dominated by CS, with additional particular fingerprints for the biocompounds and the hydrogel interaction with mucin. Rheology evidenced the gel transition temperatures of 18-22 °C for the binary hydrogels with thixotropic behavior and, respectively, no gel transition, with rheopectic behavior for the ternary hydrogel. The adhesion energies of the binary and ternary hydrogels were evaluated to be around 1.2 J/m2 and 9.1 J/m2, respectively. The hydrogels exhibited a high degree of biocompatibility, with the potential to support cell proliferation and also to promote the growth of lactobacilli. The hydrogel systems also presented significant antimicrobial and antibiofilm activity.

Efficacy and optimal dose of acetic acid to treat colonised burns wounds: protocol for a pilot randomised controlled trial

INTRODUCTION

Despite of recent advancement in the burns wound management, burn wound infection (BWI) is still one of the major cause of burns mortality. Patients who survive their burns injury still suffers from BWI related complication like delayed wound healing and poor scarring. BWI has been treated by application of topical antimicrobial agents or systemic antibiotics. Due to the global risk of developing systemic antibiotics resistance, medical research focuses on identifying single topical agent which has effective antimicrobial activity, easily available and cost effective. One such agent is acetic acid (AA). AA has been used as a topical antibacterial agent for the treatment of burns wounds for many years and has shown to have activity against gram-negative organisms including Pseudomonas aeruginosa. So far there has been no consensus on optimal concentration that has effective antimicrobial activity, frequency of application, duration of treatment and most importantly good patient's tolerability. A randomised control study is required to answer all these questions.

OBJECTIVE

To investigate the efficacy and tolerability of 0.5% and 2% of AA when applied to colonised burns wounds for 3 days after admittance to the Queen Elizabeth Hospital Birmingham.

METHODS AND ANALYSIS

This is a double-blinded, prospective, randomised, controlled, single-centre trial. Patients will be screened for eligibility in the inpatient area and those who are found to be eligible will be randomly assigned to one of two treatment groups: group 1: 0.5% AA (10 patients); group 2: 2% AA (10 patients); total number: 20 patients.

OUTCOME MEASURES

Primary outcome: Efficacy will be assessed by measuring the bacterial load from microbiology wound swabs for three consecutive days.Secondary outcomes: (1) The assessment of antimicrobial activity of AA and the minimum inhibitory concentrations. (2) Patient's tolerance by assessing Visual Analogue Scale pain score. (3) Time to 95% wound healing of treatment area. (4) Patient's perceived treatment allocation.

ETHICS AND DISSEMINATION

AceticA trial protocol was approved by the National Research Ethics Service (West Midlands-Edgbaston Research Ethics Committee; 17/WM/0407; IRAS 234132). This article refers to protocol version 5.0 dated 6 July 2020. The analysed results will be presented at national and international conferences related to management of burn patients. The generated articles based on the trial results will be submitted to peer review journals for publication.

TRIAL REGISTRATION NUMBER

ISRCTN11636684.

Biocompatible Alginate Hydrogel Film Containing Acetic Acid Manifests Broad-Spectrum Antiviral and Anticancer Activities

Acetic acid, a colourless liquid organic acid with a characteristic acrid smell, is obtained naturally and has applications in both the food and pharmaceutical industries. It has been reported to have beneficial uses for lifestyle-related diseases, and its efficient disinfectant properties are well known. In this study, an alginate crosslinked with Ca2+ hydrogel film was treated with acetic acid to explore its biological properties for biomedicine. The results showed that the novel calcium alginate/acetic acid film was biocompatible in vitro using human keratinocyte cells and in vivo with Caenorhabditis elegans. It also had antiviral properties against enveloped and non-enveloped viruses and anticancer properties against melanoma and colon cancer cells. This novel film thus showed promise for the biomedical and pharmaceutical industries, with applications for fabricating broad-spectrum antiviral and anticancer materials.

Biocompatible Chitosan Films Containing Acetic Acid Manifested Potent Antiviral Activity against Enveloped and Non-Enveloped Viruses

Chitosan films were prepared by solvent casting using an acetic acid-based solution. The films that were developed contained 15.49% of acetic acid solution (10% v/v) and showed biocompatibility in vitro in human keratinocyte HaCaT cells and potent antiviral activity against both enveloped and non-enveloped viruses. The results showed up to 99.98% and 99.92% viral inactivation against the phi 6 enveloped bacteriophage and MS2 non-enveloped bacteriophage, respectively, suggesting that this chitosan/acetic acid film is a promising material for biomedical applications that require biodegradable broad-spectrum antiviral materials.

Sweet and sour synergy: exploring the antibacterial and antibiofilm activity of acetic acid and vinegar combined with medical-grade honeys

Oxymel, a combination of honey and vinegar, has been used as a remedy for wounds and infections in historical and traditional medical settings. While honey is now clinically used to treat infected wounds, this use of a complex, raw natural product (NP) mixture is unusual in modern western medicine. Research into the antimicrobial activity of NPs more usually focuses on finding a single active compound. The acetic acid in vinegar is known to have antibacterial activity at low concentrations and is in clinical use to treat burn wound infections. Here, we investigated the potential for synergistic activity of different compounds present in a complex ingredient used in historical medicine (vinegar) and in an ingredient mixture (oxymel). We conducted a systematic review to investigate published evidence for antimicrobial effects of vinegars against human pathogenic bacteria and fungi. No published studies have explicitly compared the activity of vinegar with that of a comparable concentration of acetic acid. We then characterized selected vinegars by HPLC and assessed the antibacterial and antibiofilm activity of the vinegars and acetic acid, alone and in combination with medical-grade honeys, against Pseudomonas aeruginosa and Staphylococcus aureus. We found that some vinegars have antibacterial activity that exceeds that predicted by their acetic acid content alone, but that this depends on the bacterial species being investigated and the growth conditions (media type, planktonic vs. biofilm). Pomegranate vinegars may be particularly interesting candidates for further study. We also conclude that there is potential for acetic acid, and some vinegars, to show synergistic antibiofilm activity with manuka honey.

Photodynamic Therapy, Probiotics, Acetic Acid, and Essential Oil in the Treatment of Chronic Wounds Infected with Pseudomonas aeruginosa

As a prevalent medical problem that burdens millions of patients across the world, chronic wounds pose a challenge to the healthcare system. These wounds, often existing as a comorbidity, are vulnerable to infections. Consequently, infections hinder the healing process and complicate clinical management and treatment. While antibiotic drugs remain a popular treatment for infected chronic wounds, the recent rise of antibiotic-resistant strains has hastened the need for alternative treatments. Future impacts of chronic wounds are likely to increase with aging populations and growing obesity rates. With the need for more effective novel treatments, promising research into various wound therapies has seen an increased demand. This review summarizes photodynamic therapy, probiotics, acetic acid, and essential oil studies as developing antibiotic-free treatments for chronic wounds infected with Pseudomonas aeruginosa. Clinicians may find this review informative by gaining a better understanding of the state of current research into various antibiotic-free treatments. Furthermore. this review provides clinical significance, as clinicians may seek to implement photodynamic therapy, probiotics, acetic acid, or essential oils into their own practice.

Identification of natural CTXM-15 inhibitors from aqueous extract of endophytic bacteria Cronobactersakazaki

Nyctanthes arbor-tristis is one of India's valuable and populous medicinal plants which belongs to the family Oleaceae, and widely recognize as night jasmine. Over the years till date, different parts of the plant are used to treat or cure different ailments via various means of traditional medicine. Endophytes are organisms that live in the cell or body of other organisms with no apparent negative impact on the host which they inhabit and are of great source of novel bioactive compounds possessing important economic value. Secondary metabolites were identified in the aqueous extract of Cronobactersakazakii through quantitative phytochemical and GC-MS analysis. Antibacterial activity of the extract against clinical and ATCC strains of E. coli was assessed. Biological activity spectra of these compounds were predicted and categorized either as probably active (Pa) or probably inactive (Pi). Drug-likeness of bioactive compounds was determined as well as their ability to target protein (CTXM-15) responsible for antibiotic resistance in Gram-negative bacteria. Results revealed the presence of active compounds with pharmacological activities and considerable pharmacokinetics parameters. In addition, ligand-protein interactions of compounds with CTXM-15 proteins were identified. These results suggest that bioactive compounds of endophytic Cronobactersakazakii could contain novel chemical entities for the development of antibiotics against pathogenic microbes and other drugs for the amelioration of several infections.

Antimicrobial activity and chemical profile of wood vinegar from eucalyptus (Eucalyptus urophylla x Eucalyptus grandis - clone I144) and bamboo (Bambusa vulgaris)

Microbial resistance to drugs is a public health problem; therefore, there is a search for alternatives to replace conventional products with natural agents. One of the potential antimicrobial agents is wood vinegar derived from the carbonization of lignocellulosic raw materials. The objectives of the present work were to evaluate the antibacterial and antifungal action of two kinds of wood vinegar (WV), one of Eucalyptus urograndis wood and another of Bambusa vulgaris biomass, and determine their chemical profile. The antimicrobial effect was assessed against Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enteritidis, Escherichia coli, Streptococcus agalactiae, and Candida albicans. The minimum inhibitory concentration and the minimum bactericidal and fungicidal concentrations were determined. Micrographs of the microorganisms before and after exposure to both kinds of wood vinegar were obtained by scanning electron microscopy. The chemical profile of the eucalyptus and bamboo vinegar was carried out by gas chromatography and mass spectrometry (GC/MS). Both types of WV presented significant antimicrobial activity, with the bamboo one having a higher efficiency. Both studied pyroligneous extracts seem promising for developing natural antimicrobials due to their efficiency against pathogens. GC/MS analyses demonstrated that the chemical profiles of both kinds of WV were similar but with some significant differences. The major component of the eucalyptus vinegar was furfural (17.2%), while the bamboo WV was phenol (15.3%). Several compounds in both WVs have proven antimicrobial activity, such as acetic acid, furfural, phenol, cresols, guaiacol, and xylenols. Together, they are the major in the chemical composition of the organic fraction of both WVs. Bamboo vinegar had a more expressive content of organic acids. Micrographs of microorganisms taken after exposure to both kinds of wood vinegar displayed several cell modifications. The potential of both types of wood vinegar as a basis for natural antimicrobial products seems feasible due to their proven effect on inhibiting the microorganisms' growth assessed in this experiment.

Impact of short chain fatty acids (SCFAs) on antimicrobial activity of new β-lactam/β-lactamase inhibitor combinations and on virulence of Escherichia coli isolates

In a healthy gut microbiota, short chain fatty acids (SCFAs) are produced. The antibacterial action of SCFAs against intestinal pathogens makes them useful for ensuring the safety of food and human health. In this study, we aimed to assess the in vitro inhibitory activity of SCFAs, and to report, for the first time, their impact on the activity of new β-lactam/β-lactamase inhibitor combinations. The minimum inhibitory concentrations of acetic, propionic, and butyric acids were determined against E. coli clinical isolates recovered from gastrointestinal infections. Cefoperazone/sulbactam, ceftazidime/avibactam and cefepime/enmetazobactam are new β-lactam/β-lactamase inhibitor combinations that were studied for their combined therapeutic effects. Also, the effects of pH and concentration of SCFAs were evaluated on in vitro bacterial growth and expression of genes encoding for motility, adhesion, invasion, and biofilm formation. SCFAs were tested at concentrations of 12 mM at pH 7.4 (ileum-conditions), in addition to 60 mM and 123 mM, at pH 6.5 (colon-conditions). The tested SCFAs showed the same MIC (3750 μg ml-1 ≃ 60 mM) against all isolates. Furthermore, the addition of SCFAs to the tested β-lactam/β-lactamase inhibitor combinations greatly restored the susceptibility of the isolates. SCFAs had significant effect on bacterial growth and virulence in a pH and concentration-dependent manner; low ileal concentration potentiated E. coli growth, while higher colonic concentration significantly suppressed growth and down-regulated the expression of virulence genes (fliC, ipaH, FimH, BssS). Therefore, the significant inhibitory effect of colonic SCFAs on β-lactam/β-lactamase inhibitor combinations might lead to the development of promising treatment strategies.

Probiotic Lactobacillus Species and Their Biosurfactants Eliminate Acinetobacter baumannii Biofilm in Various Manners

Acinetobacter baumannii is a critical biofilm-forming pathogen that has presented great challenges in the clinic due to multidrug resistance. Thus, new methods of intervention are needed to control biofilm-associated infections. In this study, among three tested Lactobacillus species, Lactobacillus rhamnosus showed significant antimaturation and antiadherence effects against A. baumannii biofilm. Lactic acid (LA) and acetic acid (AA) were the most effective antibiofilm biosurfactants (BSs) produced by L. rhamnosus. This antibiofilm phenomenon produced by LA and AA was due to the strong bactericidal effect, which worked from very early time points, as determined by colony enumeration and confocal laser scanning microscope. The cell destruction of A. baumannii appeared in both the cell envelope and cytoplasm. A discontinuous cell envelope, the leakage of cell contents, and the increased extracellular activity of ATPase demonstrated the disruption of the cell membrane by LA and AA. These effects also demonstrated the occurrence of protein lysis. In addition, bacterial DNA interacted with and was damaged by LA and AA, resulting in significantly reduced expression of biofilm and DNA repair genes. The results highlight the possibility and importance of using probiotics in clinical prevention. Probiotics can be utilized as novel biocides to block and decrease biofilm formation and microbial contamination in medical equipment and during the treatment of infections. IMPORTANCE A. baumannii biofilm is a significant virulence factor that causes the biofilm colonization of invasive illnesses. Rising bacterial resistance to synthetic antimicrobials has prompted researchers to look at natural alternatives, such as probiotics and their derivatives. In this study, L. rhamnosus and its BSs (LA and AA) demonstrated remarkable antibiofilm and antimicrobial characteristics, with a significant inhibitory effect on A. baumannii. These effects were achieved by several mechanisms, including the disruption of the cell envelope membrane, protein lysis, reduced expression of biofilm-related genes, and destruction of bacterial DNA. The results provide support for the possibility of using probiotics and their derivatives in the clinical prevention and therapy of A. baumannii infections.

Changes in Burn Wound Microbiology Profile Over 14 Years of an Adult Tertiary Burn Center

Burn wound colonization can progress to invasive infection. During 14 years of this study, the burn center was relocated to a center with improved infrastructure. This study investigates the association that infrastructure, geography, and time may have on colonization. Data were collected from October 2004 to August 2018, and relocation took place in June 2010, defining the two study periods. Admission swabs were within 48 hours. Unique isolates and resistance data were analyzed and compared statistically between the two study periods. In total, 2001 patients with 24,226 wound swabs were included. Median age was 45.4 (IQR 30.2-61.6), length of stay was 11 days (IQR 6-21), and %TBSA was 5.5 (IQR 2.5-11). Staph. aureus (33.7/100 patients) and Pseudomonas spp. (13.1/100 patients) were the most prevalent bacterial growths. After admission, the prevalence of methicillin resistant Staph. aureus, Coliform spp., and Aci. baumanni was greater in the first site, and Candida spp. colonization was higher in the second study period site. The prevalence of patients affected by multi-drug-resistant organisms was lower in the second study site (13.5/100 patients vs 16.6/100 patients; P < .05). There are differences in burn wound colonization across time, within the same region. Candida spp. growth has been shown to be increased over time and represents an added challenge. Awareness facilitates effective empirical antimicrobial therapies and protocols locally.

Treasure from trash - Is Ecoenzyme the new panacea in conservative dentistry and endodontics?

Context

Endodontic biofilm eradication is achieved by chemo-mechanical disinfection. The search for a safer, nontoxic irrigant led us to a natural product, Ecoenzyme.

Aim

This study aims to analyze Ecoenzyme (EE) and explore its antimicrobial and biofilm disrupting activity against a 1-week mature multi-species biofilm.

Materials and Methods

Qualitative assessment of the phytochemicals present in EE was conducted. Minimal inhibitory concentration (MIC), minimum bactericidal concentration, and zone of inhibition (ZOI) were recorded. Multi-species biofilm of Streptococcus mutans (MTCC 497), Lactobacillus acidophilus (MTCC 10307), and Enterococcus faecalis (ATCC 29212) was grown and time-kill assay was performed to test biofilm disruption for EE, 3.5% sodium hypochlorite (NaOCl) (control). Student's t-test and one-way ANOVA with post hoc analysis were conducted for ZOI and time-kill assay, respectively. Statistical significance was set at P ≤ 0.05.

Results

EE contained secondary metabolites having antibacterial properties. MIC was 25% (S. mutans), 50% (E. faecalis), and >50% (L. acidophilus). EE disrupted ~90% of biofilm species in 5 min of exposure while NaOCl achieved ~99.9% reduction. Further reduction by EE progressed over 20 min after which no viable bacteria in the biofilm was cultivable.

Conclusions

Lemon peel Ecoenzyme (EE) is antimicrobial with effective biofilm-disrupting properties on a mature multi-species biofilm. However, its effects were slower than 3.5% sodium hypochlorite.

Non-Targeted Metabolomic Profiling Identifies Metabolites with Potential Antimicrobial Activity from an Anaerobic Bacterium Closely Related to Terrisporobacter Species

This work focused on the metabolomic profiling of the conditioned medium (FS03CM) produced by an anaerobic bacterium closely related to Terrisporobacter spp. to identify potential antimicrobial metabolites. The metabolome of the conditioned medium was profiled by two-channel Chemical Isotope Labelling (CIL) LC-MS. The detected metabolites were identified or matched by conducting a library search using different confidence levels. Forty-eight significantly changed metabolites were identified with high confidence after the growth of isolate FS03 in cooked meat glucose starch (CMGS) medium. Some of the secondary metabolites identified with known antimicrobial activities were 4-hydroxyphenyllactate, 3-hydroxyphenylacetic acid, acetic acid, isobutyric acid, valeric acid, and tryptamine. Our findings revealed the presence of different secondary metabolites with previously reported antimicrobial activities and suggested the capability of producing antimicrobial metabolites by the anaerobic bacterium FS03.

A COST Action on microbial responses to low pH: Developing links and sharing resources across the academic-industrial divide

We present work of our COST Action on "Understanding and exploiting the impacts of low pH on micro-organisms". First, we summarise a workshop held at the European Federation of Biotechnology meeting on Microbial Stress Responses (online in 2020) on "Industrial applications of low pH stress on microbial bio-based production", as an example of an initiative fostering links between pure and applied research. We report the outcomes of a small survey on the challenging topic of developing links between researchers working in academia and industry that show that, while people in different sectors strongly support such links, barriers remain that obstruct this process. We present the thoughts of an expert panel held as part of the workshop above, where people with experience of collaboration between academia and industry shared ideas on how to develop and maintain links. Access to relevant information is essential for research in all sectors, and because of this we have developed, as part of our COST Action goals, two resources for the free use of all researchers with interests in any aspects of microbial responses to low pH. These are (1) a comprehensive database of references in the literature on different aspects of acid stress responses in different bacterial and fungal species, and (2) a database of research expertise across our network. We invite the community of researchers working in this field to take advantage of these resources to identify relevant literature and opportunities for establishing collaborations.

Antibiofilm Activity of Weissella spp. and Bacillus coagulans Isolated from Equine Skin against Staphylococcus aureus

The aim of this study was to evaluate the antimicrobial and antibiofilm activity of Weissella cibaria, Weissella hellenica and Bacillus coagulans, isolated from equine skin, against biofilm-forming Staphylococcus aureus CCM 4223 and clinical isolate methicillin-resistant S. aureus (MRSA). Non-neutralized cell-free supernatants (nnCFS) of tested skin isolates completely inhibited the growth and biofilm formation of S. aureus strains and caused dispersion of the 24 h preformed biofilm in the range of 21-90%. The majority of the pH-neutralized cell-free supernatants (nCFS) of skin isolates inhibited the biofilm formation of both S. aureus strains in the range of 20-100%. The dispersion activity of B. coagulans nCFS ranged from 17 to 77% and was significantly lower than that of nnCFS, except for B. coagulans 3T27 against S. aureus CCM 4223. Changes in the growth of S. aureus CCM 4223 in the presence of catalase- or trypsin-treated W. hellenica 4/2D23 and W. cibaria 4/8D37 nCFS indicated the role of peroxides and/or bacteriocin in their antimicrobial activities. For the first time, the presence of the fenD gene, associated with biosurfactants production, was detected in B. coagulans. The results of this study showed that selected isolates may have the potential for the prevention and treatment of biofilm-forming S. aureus infections.

Evolution of the spontaneous sourdoughs microbiota prepared with organic or conventional whole wheat flours from South Brazil

The purpose of this study was to compare the composition and stability of bacteria and fungi communities during the propagation of sourdoughs prepared with organic or conventional whole wheat (Triticum aestivum) flours from South Brazil. Sourdoughs were prepared and samples were collected during different fermentation times (0 to 216 h). Total DNA of sourdough samples were extracted and the 16S rRNA gene and Internal Transcribed Spacer region were sequenced by MiSeq-Illumina. A total of 43 and 56 OTUs were identified and defined as core taxa in the bacterial and fungal communities, respectively. The analysis revealed increases in the relative abundances of the lactic acid (Pediococcus pentosaceus, Weissella hellenica and Limosilactobacillus pontis) and acetic acid bacteria (Gluconobacter frateurii and Acetobacter tropicalis) during the sourdough propagation. The filaments fungi, Alternaria tenuissima, Fusarium culmorum, Fusarium petersiae and Microdochium seminicola remained more stable in organic than conventional during propagation cycles. After 216 h of fermentation, both sourdoughs were dominated by acid- and salt-tolerant yeast Issatchenkia orientalis (syn Pichia kudriavzevii, and Candida glycerinogenes). In conclusion, there were no significant differences in microbial communities among the sourdough samples. This study revealed that both flours contain autochthonous LAB, AAB, and yeasts with biotechnological applications in sourdough bread-making.

Phase 1 safety trial of a natural product cocktail with antibacterial activity in human volunteers

New antibiotics are urgently needed to reduce the health burden of antibiotic-resistant bacterial infection. Natural products (NPs) derived from plants and animals are a current focus of research seeking to discover new antibacterial molecules with clinical potential. A cocktail of NPs based on a medieval remedy for eye infection eliminated biofilms of several highly antibiotic-resistant bacterial species in laboratory studies, and had a promising safety profile in vitro and in a mouse model. A necessary prelude to refining this remedy into a defined, synthetic mixture suitable for testing with wound infections is to firstly establish safety when applied to healthy human skin. We aimed to assess skin-related outcomes of the preparation in a sample of healthy volunteers. This prospective, single arm, non-randomised Phase I clinical trial consisted of a single patch test intervention with 48-h follow-up. Volunteers were staff, students and members of the public recruited from the University of Warwick and surrounding locality. Adults aged 18-79 years, with no history of severe immunity-related disease, diabetes, recent infection, or known pregnancy were eligible. A 100 µl application of a filter-sterilised NP mixture, comprising ground garlic, onion, white wine and bovine bile, was applied to skin on the upper arm and covered with a dressing. The primary outcome was skin-related adverse events over 48 h. Digital photographs were captured where bothersome, salve-related events were reported. 109 volunteers, aged 18-77 years, were recruited between June and July 2021. Sample mean age was 37.6 (SD 16.1) years, and 63 (58%) participants were female. Outcome data were obtained for 106/109 (97%); two participants were lost to follow-up and one removed the skin patch after nine hours due to a bothersome garlic odour. Twenty-one (19.8%) participants reported any patch-test related sign or symptom; of these 14 (13.2%) participants reported minor events related to the salve, including itchiness, redness, or garlic odour. No serious events were reported. We found no evidence of serious skin-related adverse events related to the NP preparation.Trial registration: International Standard Randomised Controlled Trial Number (ISRCTN10773579). Date registered: 08/01/2021.

Irrigation Solutions in Total Joint Arthroplasty

INTRODUCTION

Despite advancements in the field of adult reconstruction, prosthetic joint infection (PJI) remains a common and devastating complication of total joint arthroplasty. Eradication of these infections can often prove difficult, and they remain a source of considerable morbidity and mortality. This clinical review paper will focus on some of the more commonly used irrigation solutions; povidone-iodine (PI), chlorhexidine (CHG), acetic acid (AA), hydrogen peroxide (HP), antibiotic irrigations, taurolidine, and polyhexanide-betaine (PB).

SUMMARY OF THE EVIDENCE

Significant research has been performed on the prevention of PJI, including use of intraoperative joint irrigation solutions. Several solutions have been theorized to aid in infection prevention, but no evidence-based practice guidelines in this area of orthopaedics have been established. There is a paucity of prospective randomized control trials to compare the efficacy of these joint irrigation solutions.

CONCLUSIONS

The authors present a review regarding seven major categories of commonly used intraoperative joint irrigation solutions. The current literature fails to demonstrate a clear consensus for a preferred solution and concentration for povidone-iodine, chlorhexidine, hydrogen peroxide, acetic acid, antibiotic irrigations, taurolidine, and polyhexanide-betaine. Prospective, randomized control trials directly comparing these different irrigation solutions are needed.

Effect of Stabilized Hypochlorous Acid on Re-epithelialization and Bacterial Bioburden in Acute Wounds: A Randomized Controlled Trial in Healthy Volunteers

The aim of this randomized controlled trial was to evaluate the wound-healing effect and antimicrobial properties of a novel stabilized hypochlorous acid solution on acute wounds, using a suction blister wound model. One suction blister was raised and de-roofed on each forearm in 20 healthy volunteers. Stabilized hypochlorous acid/control (sterile 0.9% NaCl) solutions were assigned to either wound by randomization. Wounds were irrigated and treated on days 0, 2 and 4. Re-epithelialization was assessed blindly by digital planimetry, and bacterial growth was assessed as the number of colony-forming units cultured from surface swabs. Hypochlorous acid solution increased the degree of re-epithelialization on day 4 by 14% compared with the control solution (95% confidence interval (CI) 6.8–20%, p = 0.00051) and was not inferior (p < 0.0001) to the control solution on day 10 (0.3%, 95% CI –1.3–1.9%). Median bacterial counts were lower with stabilized hypochlorous acid compared with control and were further reduced after irrigation and treatment of both groups on day 4, but remained lower in the stabilized hypochlorous acid group compared with the control group. This study demonstrates immediate and durable antimicrobial action and a beneficial effect on acute wound healing after irrigation and treatment with a stabilized hypochlorous acid formulation.

Comparison of the effectiveness of savlon antiseptic with povidone-iodine for acinetobacter baumannii infected wounds in white rats (Rattus Norvegicus)

Wound washing with antiseptic liquid is one step in the management of chronic wounds. In infected wounds, washing with antiseptic is expected to reduce bacterial colonies and help eradicate infection. One of the important pathogenic bacteria is Acinetobacter Baumannii. These opportunistic germs can form colonies, especially in patients receiving broad-spectrum antibiotic therapy, treatment in the ICU, and on skin affected by burns. Antiseptic commonly used to wash wound are Savlon and Povidone-iodine 10%. Both antiseptic are broad spectrum antisepctic, kill gram negative and gram positive bacteria. However Savlon could caused skin irritation. Therefore dilution is needed to prevent this effect. This study was intended to determine the difference and comparison of the effectiveness of Savlon and Povidone iodine antiseptic to bacterial growth on wound infected by Acinetobacter Baumannii.  This study is an experimental study with a randomized controlled trial without blinding. The wound research procedure was made on the right and left sides of the rat's back with a size of 1x1 cm each. Wounds that have been contaminated with Acinetobacter Baumannii are left for 4 hours. After 4 hours the wound will be washed and irrigated. The wound that has been made is closed with a transparent dressing.

An assessment of the evidence for antibacterial activity of stinging nettle (Urtica dioica) extracts

Stinging nettles (Urtica spp.) have been used in a diverse range of traditional and historical medicines from around the world for the treatment of skin diseases, wounds, urinary disorders, respiratory diseases, bone and joint pain, anaemia and other circulatory problems, as well as in cosmetic preparations for skin and haircare. As part of an interdisciplinary exploration of nettle-based remedies, we performed a systematic review of published evidence for the antimicrobial activity of Urtica spp. extracts against bacteria and fungi that commonly cause skin, soft tissue and respiratory infections. We focussed on studies in which minimum inhibitory concentration (MIC) assays of U. dioica were conducted on the common bacterial opportunistic pathogens Escherichia coli , Pseudomonas aeruginosa , Klebsiella pneumoniae and Staphylococcus aureus . No studies used fresh leaves (all were dried prior to use), and no studies prepared nettles in weak acid (corresponding to vinegar) or in fats/oils, which are common combinations in historical and traditional preparations. We addressed this gap by conducting new antibacterial tests of extracts of fresh U. dioica leaves prepared in vinegar, butter or olive oil against P. aeruginosa and S. aureus . Our systematic review and additional experimental data leads us to conclude that there is no strong evidence for nettles containing molecules with clinically useful antimicrobial activity. It seems most likely that the utility of nettles in traditional topical preparations for wounds may simply be as a 'safe' absorbent medium for keeping antibacterial (vinegar) or emollient (oils) ingredients at the treatment site.