Search Results (436)

Food waste has emerged as a critical worldwide concern, resulting in environmental deterioration and economic detriment. Bio-based natural polymer coatings and films have emerged as a sustainable solution to food preservation challenges, particularly in reducing postharvest losses and extending shelf life. Compared to their synthetic counterparts, these polymers, such as chitosan, starch, cellulose, proteins, and alginate, are derived from renewable sources that are biodegradable, safe, and functional. Within this context, this review examines the various bio-based natural polymer coatings and films as biodegradable, edible alternatives to conventional packaging solutions. It examines the different fabrication methods, like solution casting, electrospinning, and spray coating, and incorporates antimicrobial agents to enhance performance. Emphasis is placed on their mechanical, barrier, and antimicrobial properties, their application in preserving fresh produce, how they promote food safety and environmental sustainability, and accompanying limitations. This review highlights the importance of bio-based natural polymer coatings and films as a promising, eco-friendly solution to enhancing food quality, safety, and shelf life while addressing global sustainability challenges. Full article

Background: Salivary pH plays a critical role in oral health by influencing enamel demineralization, buffering capacity, and the ecology of oral microbiota. Essential oils such as Origanum vulgare (oregano) possess well-documented antimicrobial properties that may reduce acidogenic bacterial activity. However, the effects of edible delivery systems like jellies on salivary pH modulation and their potential interactions with hormonal states remain poorly understood. Methods: This study evaluated the in vitro antimicrobial activity of an oregano-oil-based jelly formulation against standard bacterial (Staphylococcus aureus, Streptococcus pyogenes, and Escherichia coli) and fungal (Candida albicans) strains using the Kirby–Bauer disc diffusion method. Additionally, a human trial (n = 91) measured salivary pH before and after administration of the oregano-oil jelly. Participants were characterized by age, smoking status, menopausal status, and presence of menstruation. Multiple linear regression was used to identify predictors of final salivary pH. Results: The oregano-oil jelly demonstrated strong in vitro antimicrobial activity, with inhibition zones up to 8 mm for E. coli and C. albicans. In vivo, mean unstimulated salivary pH increased from 6.94 to 7.07 overall, indicating a mild alkalinizing effect. However, menstruating participants showed a significant decrease in final pH (from 7.03 to 6.78). Multiple regression identified menstruation as a significant negative predictor (β = −0.377, p < 0.001) and initial pH as a positive predictor (β = +0.275, p = 0.002). Menopausal status was not a significant predictor, likely due to the small sample size. Conclusions: Oregano-oil jellies may represent a promising natural approach to support oral health by increasing salivary pH and providing strong antimicrobial activity. However, physiological states such as menstruation can significantly modulate this response, underscoring the importance of personalized or phase-aware oral care strategies. Further studies with larger, diverse cohorts and controlled hormonal assessments are needed to validate these findings and optimize product formulations. Full article

Background/Objectives: The emergence of antimicrobial resistance represents a critical global health threat, requiring the discovery of novel bioactive compounds. Fungi from Amazonian biodiversity are promising sources of secondary metabolites with potential antimicrobial activity. This study aimed to investigate the production of antimicrobial compounds by two Amazonian fungal strains using the OSMAC (One Strain–Many Compounds) approach. Methods: Two fungal strains, Talaromyces pinophilus CCM-UEA-F0414 and Penicillium paxilli CCM-UEA-F0591, were cultivated under five distinct culture media to modulate secondary metabolite production. Ethyl acetate extracts were prepared and evaluated for antimicrobial activity against Gram-positive and Gram-negative bacteria, as well as pathogenic yeasts. Chemical characterization was performed using thin-layer chromatography (TLC), Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet–Visible (UV-Vis) spectroscopy, and Ultra-High-Performance Liquid Chromatography with Diode Array Detection (uHPLC-DAD). Results: The extracts exhibited significant antimicrobial activity, with minimum inhibitory concentrations (MICs) ranging from 78 to 5000 µg/mL. Chemical analyses revealed the presence of phenolic compounds, particularly caffeic and chlorogenic acids. Variations in the culture media substantially affected both the metabolite profiles and antimicrobial efficacy of the extracts. Conclusions: The OSMAC strategy effectively enhanced the metabolic diversity of the Amazonian fungal strains, leading to the production of bioactive metabolites with antimicrobial potential. These findings support the importance of optimizing culture conditions to unlock the biosynthetic capacity of Amazonian fungi as promising sources of antimicrobial agents. Full article

Acinetobacter baumannii is a multidrug-resistant bacterium that has gained significant attention in recent years due to its involvement in a growing number of hospital-acquired infections. The World Health Organization has classified it as a critical priority pathogen, underscoring the urgent need for new therapeutic strategies. Post-translational modifications (PTMs), such as phosphorylation, play essential roles in various bacterial processes, including antibiotic resistance, virulence or biofilm formation. Although proteomics has increasingly enabled their characterization, the identification of phosphorylated peptides remains challenging, primarily due to the enrichment procedures. In this study, we focused on characterizing serine, threonine, and tyrosine phosphorylation in the A. baumannii ATCC 17978 strain. We optimized three parameters for phosphopeptide enrichment using titanium dioxide (TiO₂) beads (number of enrichment fractions between the phosphopeptides and TiO₂ beads, the quantity peptides and type of loading buffer) to determine the most effective conditions for maximizing phosphopeptide identification. Using this optimized protocol, we identified 384 unique phosphorylation sites across 241 proteins, including 260 novel phosphosites previously unreported in A. baumannii. Several of these phosphorylated proteins are involved in critical bacterial processes such as antimicrobial resistance, biofilm formation or pathogenicity. We discuss these proteins, focusing on the potential functional implications of their phosphorylation. Notably, we identified 34 phosphoproteins with phosphosites localized at functional sites, such as active sites, multimer interfaces, or domains important for structural integrity. Our findings significantly expand the current phosphoproteomic landscape of A. baumannii and support the hypothesis that PTMs, particularly phosphorylation, play a central regulatory role in its physiology and pathogenic potential. Full article

Background: Antimicrobial resistance (AMR) is increasingly acknowledged as a critical global challenge, posing serious risks to human and animal health and potentially disrupting poultry production systems. Commensal bacteria such as Staphylococcus spp., Enterococcus spp., and Escherichia coli may serve as important reservoirs and vectors of resistance genes. Objectives: This study aimed to assess the AMR profiles of bacterial strains isolated from industrial chicken farms in the Dél-Alföld region of Hungary, providing region-specific insights into resistance dynamics. Methods: A total of 145 isolates, including Staphylococcus spp., Enterococcus spp., and E. coli isolates, were subjected to minimum inhibitory concentration (MIC) testing against 15 antimicrobial agents, following Clinical and Laboratory Standards Institute (CLSI) guidelines. Advanced multivariate statistics, machine learning algorithms, and network-based approaches were employed to analyze resistance patterns and co-resistance associations. Results Multidrug resistance (MDR) was identified in 43.9% of Staphylococcus spp. isolates, 28.8% of Enterococcus spp. isolates, and 75.6% of E. coli isolates. High levels of resistance to florfenicol, enrofloxacin, and potentiated sulfonamides were observed, whereas susceptibility to critical antimicrobials such as imipenem and vancomycin remained largely preserved. Discussion: Our findings underscore the necessity of implementing region-specific AMR monitoring programs and strengthening multidisciplinary collaboration within the “One Health” framework with proper animal hygiene and biosecurity measures to limit the spread of antimicrobial resistance and protect both animal and human health. Full article

Background: The landscape of antimicrobial therapy is undergoing a profound transformation; the contemporary arsenal of antimicrobials, particularly those with extended half-lives and enhanced tissue penetration, necessitates critically reassessing these traditional paradigms. The growing emphasis on antimicrobial stewardship programs has underscored the importance of optimizing antimicrobial agents to minimize the development and spread of resistance. Shorter treatment durations, when clinically appropriate, represent a key strategy in this endeavor. Methods: This narrative review provides a comprehensive synthesis of current evidence on the duration of antimicrobial therapy, with a particular focus on the clinical and pharmacological implications of novel agents, including long-acting formulations. Results: We critically examine the pharmacokinetic and pharmacodynamic properties of these agents, evaluate the opportunities and limitations associated with treatment shortening strategies, and underscore the pivotal role of antimicrobial stewardship in optimizing therapeutic outcomes within an increasingly complex and evolving landscape. Conclusions: The future of antimicrobial therapy lies in a personalized approach, where treatment decisions are tailored to the individual patient, but detailed clinical trials are necessary to evaluate these approaches. Full article

Microbiological contamination of healthcare workers’ gowns represents a critical risk for the transmission of healthcare-associated infections (HAIs). Despite their use as protective equipment, gowns can act as reservoirs of antibiotic-resistant bacteria, favouring the spread of pathogens between healthcare workers and patients. The presence of these resistant bacteria on healthcare workers’ gowns highlights the urgent need to address this risk as part of infection control strategies. The aim of this work was to assess the microbiological risks associated with the contamination of healthcare staff gowns with Gram-negative bacteria, including the ESKAPE group, and their relationship with antimicrobial resistance. An observational, cross-sectional, prospective study was conducted in 321 hospital workers. The imprinting technique was used to quantify the bacterial load on the gowns, followed by bacterial identification by MALDI-TOF mass spectrometry. In addition, antimicrobial resistance profiles were analysed, and tests for carbapenemases and BLEE production were performed. The ERIC-PCR technique was also used for molecular analysis of Pantoea eucrina clones. Several Gram-negative bacteria were identified, including bacteria of the ESKAPE group. The rate of microbiological contamination of the gowns was 61.05% with no association with the sex of the healthcare personnel. It was observed that critical areas of the hospital, such as intensive care units and operating theatres, showed contamination by medically important bacteria. In addition, some strains of P. eucrina showed resistance to carbapenemics and cephalosporins. ERIC-PCR analysis of P. eucrina isolates showed genetic heterogeneity, indicating absence of clonal dissemination. Healthcare personnel gowns are a significant reservoir of pathogenic bacteria, especially in critical areas of Hospital Juárez de México. It is essential to implement infection control strategies that include improving the cleaning and laundering of gowns and ideally eliminating them from clothing to reduce the risk of transmission of nosocomial infections. Full article

Background/Objectives: The formation of oral biofilms in periodontal pockets and around dental implants with induction of periodontitis or peri-implantitis is an increasing problem in dental health. The intelligent design of a biofilm makes the bacteria embedded in the biofilm matrix highly tolerant to antiseptic therapy, often resulting in tooth or implant loss. The question therefore arises as to which mouthwashes have eradication potential against oral biofilm. Methods: A human oral biofilm model was developed based on donated blood plasma combined with buffy coats, inoculated with oral pathogenic bacterial species found in periodontal disease (Actinomyces naeslundii, Fusobacterium nucleatum, Streptococcus mitis, and Porphyromonas gingivalis). Over a span of 7 days, we tested different mouth rinsing and antiseptic solutions (Chlorhexidine, Listerine^®, NaOCl, Octenisept^®, and Octenident^®) covering the matured biofilm with 24 h renewal. Phosphate-buffered saline (PBS) was used as a control. Bacterial growth patterns were detected via quantitative polymerase chain reaction (qPCR) after 2, 4, and 7 days of treatment. Results: While all groups showed initial bacterial reduction, the control group demonstrated strong regrowth from day 2 to 4. Listerine showed a near-significant trend toward bacterial suppression. Additionally, strain-specific efficacy was observed, with Octenisept^® being most effective against Streptococcus mitis, Octenident^® and NaOCl showing superior suppression of Actinomyces naeslundii, and Listerine^® outperforming other solutions in reducing Fusobacterium nucleatum. Donor-specific, individual variability further influenced treatment outcomes, with distinct trends in bacterial suppression and regrowth observed across donors. Conclusions: These findings underscore the complexity of biofilm-associated infections and highlight the importance of targeted therapeutic approaches for managing bacterial biofilms. In this experiment, the donor-specific outcomes of the antimicrobial effects of the solutions may indicate that genetic predisposition/tolerance to oral infections appears to play a critical role in the control of oral biofilms. Full article

Proteus vulgaris is an emerging multidrug-resistant (MDR) foodborne pathogen that poses a significant threat to food safety and public health, particularly in aquaculture systems where antibiotic use may drive resistance development. Despite its increasing clinical importance, the genomic mechanisms underlying antimicrobial resistance (AMR) and virulence transmission in foodborne Proteus vulgaris remain poorly understood, representing a critical knowledge gap in One Health frameworks. To investigate its AMR and virulence transmission mechanisms, we analyzed strain P3M from Penaeus vannamei intestines through genomic island (GI) prediction and comparative genomics. Our study provides the first comprehensive characterization of mobile genetic elements in aquaculture-derived Proteus vulgaris, identifying two virulence-associated GIs (GI12/GI15 containing 25/6 virulence genes) and three AMR-linked GIs (GI7/GI13/GI16 carrying 1/1/5 antibiotic resistance genes (ARGs)), along with a potentially mobile ARG cluster flanked by IS elements (tnpA-tnpB), suggesting horizontal gene transfer capability. These findings elucidate previously undocumented genomic mechanisms of AMR and virulence dissemination in Proteus vulgaris, establishing critical insights for developing One Health strategies to combat antimicrobial resistance and virulence in foodborne pathogens. Full article

Antimicrobial resistance (AMR) poses a growing threat to global health, and its spread through the food chain is gaining increasing attention. While AMR in food of animal origin has been extensively studied, less is known about its prevalence in plant-based foods, particularly fresh and ready-to-eat (RTE) vegetables. This study investigated the occurrence of antimicrobial-resistant bacteria in fresh and RTE vegetables. Isolates were subjected to antimicrobial susceptibility testing and molecular analyses for the characterization of antimicrobial resistance genes (ARGs). A significant proportion of samples were found to harbor antimicrobial-resistant bacteria, including multidrug-resistant strains. Several ARGs, including those encoding extended-spectrum β-lactamases (ESBLs) and resistance to critically important antimicrobials, were detected. The findings point to environmental contamination—potentially originating from wastewater reuse and agricultural practices—as a likely contributor to AMR dissemination in vegetables. The presence of antimicrobial-resistant bacteria and ARGs in fresh produce raises concerns about food safety and public health. The current regulatory framework lacks specific criteria for monitoring AMR in vegetables, highlighting the urgent need for surveillance programs and risk mitigation strategies. This study contributes to a better understanding of AMR in the plant-based food sector and supports the implementation of a One Health approach to address this issue. Full article

Background: Multidrug-resistant bacteria (MDRB) represent a significant challenge in intensive care units (ICUs), as they limit treatment options, prolong hospital stays, and escalate healthcare costs. Respiratory ICUs are particularly affected due to the high prevalence of chronically ill patients with recurrent infections. Understanding the impact of culture positivity and MDRB on clinical outcomes and readmission rates is essential for enhancing patient care and addressing the growing burden of antimicrobial resistance. Methods: This retrospective study was conducted in a specialized respiratory ICU at a tertiary care hospital between 1 January 2019, and 1 January 2020. A total of 695 ICU admissions were analyzed, with patients grouped based on readmission status and culture results. Demographic, clinical, and laboratory data were reviewed. Statistical analyses were performed using appropriate tests, with p-values ≤ 0.05 considered statistically significant. Results: Among the 519 unique patients, 65 experienced ICU readmissions. Male patients were significantly more likely to be readmitted (p = 0.008). Culture positivity was predominantly observed in respiratory samples, with Klebsiella spp. identified as the most common pathogen. MDRB prevalence exceeded 60% in both groups, significantly prolonging ICU stays (p = 0.013). However, no significant differences in survival rates were observed between MDRB-positive and MDRB-negative groups. Notably, patients with readmissions had lower C-reactive protein (CRP) levels both during admission and at discharge compared to non-readmitted patients (p = 0.004). This paradox may reflect a subclinical inflammatory response associated with bacterial colonization rather than active infection, particularly in patients with chronic respiratory diseases. Conclusions: MDRB infections and culture positivity are key contributors to prolonged ICU stays, resulting in increased healthcare costs. Implementing effective strategies to manage MDRB infections is critical for improving outcomes in respiratory ICUs and reducing associated risks. This study underscores the growing burden of MDRB and highlights the importance of enhanced antimicrobial stewardship in respiratory ICUs. Full article

Background: Canine pyoderma and otitis externa are prevalent bacterial skin infections in veterinary practice, frequently complicated by the emergence of multidrug-resistant (MDR) pathogens. Objectives: To investigate the frequency, antimicrobial resistance (AMR) profiles, and frequency of MDR bacterial isolates from dogs with pyoderma or otitis externa in Hong Kong. Methods: A retrospective study of bacterial isolates from 215 clinical samples collected from dogs presenting with pyoderma (n = 63) or otitis externa (n = 152) at veterinary clinics across Hong Kong between 2018 and 2022. Bacterial isolates were identified and subjected to antimicrobial susceptibility testing against 13 antimicrobial classes. Results: Staphylococcus spp., particularly S. pseudintermedius, were the most commonly isolated species, followed by Pseudomonas spp. and Proteus spp. High resistance rates were observed for orbifloxacin (61.3% in pyoderma; 76.7% in otitis externa), doxycycline (59.3%; 69.2%), clindamycin (62%; 68.9%), and enrofloxacin (50%; 55.5%). Most isolates were sensitive to ofloxacin, ticarcillin–clavulanate, tobramycin, ciprofloxacin, cefpodoxime, cefuroxime, and cefixime. MDR was detected in 67.5% of pyoderma and 66.8% of otitis externa isolates. Gram-negative bacteria exhibited significantly higher MDR rates than Gram-positive isolates. The multiple antibiotic resistance (MAR) index averaged 0.41 for pyoderma and 0.52 for otitis externa isolates. We found no significant associations between MDR and non-modifiable risk factors (i.e., age, sex, breed, and reproductive status). Conclusions: These findings highlight the critical need for prudent antimicrobial use and continuous surveillance of AMR trends in companion animals. A higher focus should be placed on topical antiseptic therapy, with oral antibiotics used only in exceptional cases and after susceptibility testing. From a One Health perspective, the potential transmission of MDR bacteria between companion animals and humans underscores the importance of a coordinated approach to antimicrobial stewardship across both veterinary and human medicine. Full article

The discovery of new microbial metabolites is essential to combat the alarming rise in antimicrobial resistance and to meet emerging medical needs. This work critically reviews current strategies for identifying antimicrobial compounds, emphasizing the potential of microorganisms as a rich source of bioactive secondary metabolites. This review explores innovative methods, such as investigating extreme environments where adverse conditions favor the emergence of unique metabolites; developing techniques, like the iChip, to cultivate previously uncultivable bacteria; using metagenomics to analyze complex samples that are difficult to isolate; and integrates artificial intelligence to accelerate genomic mining, structural prediction, and drug discovery optimization processes. The importance of overcoming current challenges, such as replicating findings, low research investment, and the lack of adapted collection technologies, is also emphasized. Additionally, this work analyzes the crucial role of bacterial resistance and the necessity of a holistic approach involving new technologies, sustained investment, and interdisciplinary collaboration. This work emphasizes not only the current state of metabolite discovery but also the challenges that must be addressed to ensure a continuous flow of new therapeutic molecules in the coming decades. Full article

This study investigated how factors associated with Sinner’s principle—namely temperature, time, and the chemical composition of detergents—affected the antimicrobial efficacy of domestic dishwashers, particularly during short cycles. These are of particular interest, because many consumers refrain from using long cycles while it is still unclear if short cycles can provide a sufficient level of hygiene. Thus, we chose a range of bacterial strains, including standard test strains such as Micrococcus luteus and Enterococcus faecium, as well as important foodborne pathogens such as Escherichia coli, Staphylococcus aureus, and Salmonella enterica. To account for the complexity of dishwasher cycles, we correlated hygiene efficacy with area under the curve (AUC) measurements derived from the respective cycle profiles. Our findings revealed that the reductions in M. luteus and E. faecium were minimally affected by the reference detergent. In contrast, a high-tier market detergent demonstrated a significant decrease in bacterial counts. Notably, both strains exhibited reduced efficacy at a main cycle temperature of 45 °C, suggesting that temperatures below 50 °C might represent a critical threshold at which the hygiene efficacy of domestic dishwashing processes declines. However, since food-related pathogens were more susceptible to the dishwashing process, even lower temperatures might deliver a sufficient level of hygiene. Plotting the logarithmic reduction/AUC ratio against the AUC indicated that the main cycle contributed approximately 10-fold more to microbial reduction than the rinse cycle. Furthermore, the antimicrobial impact of detergents was greatest at the lowest AUC values (i.e., during short cycles). Taken together, our results suggest that the applied chemistry may help to enhance antimicrobial performance especially in short dishwashing cycles. Full article

Background and Aim: Pneumococcal pneumonia is a major cause of death globally, emphasizing the importance of vaccination, especially in low- and middle-income countries. In Iran, the 13-valent pneumococcal conjugate vaccine (PCV13) is available exclusively through private healthcare systems, resulting in a lack of studies on the prevalence of Streptococcus pneumoniae (S. pneumoniae) serotypes among vaccinated children. This research aimed to explore and compare the prevalence of nasopharyngeal pneumococcal carriage, serotype distribution, and antibiotic resistance patterns in healthy PCV13-vaccinated and -unvaccinated children. Methods: From August 2023 to November 2024, a multi-center, cross-sectional observational study was conducted in Tehran, Iran. This study included 204 nasopharyngeal samples collected from children aged from 18 to 59 months, involving both cases of children vaccinated with PCV13 and unvaccinated populations. S. pneumoniae was identified through a combination of culture methods and biochemical tests, confirmed by real-time PCR. Serotyping was achieved using cpsB sequencing, and the minimum inhibitory concentration method was employed to assess antibiotic resistance. Results: This study revealed similar S. pneumoniae carriage rates between PCV13-vaccinated and -unvaccinated Iranian children (20.6% vs. 21.6%). Serotypes 23F and 19F were prevalent in unvaccinated children, while 15B/15C was more prevalent in PCV13-vaccinated children. The included S. pneumoniae serotypes in PCV13 were detected more in the unvaccinated group. PCV13-vaccinated children exhibited no penicillin-resistant pneumococcal isolates, although four isolates were non-susceptible in unvaccinated children. Both groups showed substantial resistance to erythromycin and SXT. Previous respiratory infections, daycare attendance, residence in Tehran, and a history of antibiotic consumption increased the risk of pneumococcal carriage. Conclusions: PCV13 vaccination influences pneumococcal serotype distribution and antimicrobial susceptibility, although there was no significant difference regarding carriage rates between vaccinated and unvaccinated groups. These findings highlight the critical importance of vaccination in reducing invasive serotypes and antimicrobial resistance in children under five years old, emphasizing the importance of national PCV vaccination programs alongside continuous serotype surveillance. Full article