Bioactive proteins and peptides derived from fruits, vegetables, meat or fish have great potential as functional foods or as substitutes for clinically used antimicrobials. In recent years, it has also been shown that the fungal kingdom could be a source of these compounds. This study investigated the bioactivity of an extract of the oyster mushroom Pleurotus ostreatus and its hydrolysate against Aspergillus spp. and Penicillium spp. reference strains (no. of the patent application: P.445190).

The antifungal activity of the tested extract and hydrolysate was evaluated against moulds reference (Aspergillus fumigatus ATCC 46645, Aspergillus niger ATCC 16404, Penicillium chrysogenum ATCC 10106), from the collection of the Department of Pharmaceutical Microbiology, Medical University of Lublin, Poland, by using the microdilution broth method according to EUCAST guidelines. The in vitro activity of the test compounds (initial concentration of 50 mg/mL) was determined on the basis of the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC). The MFC/MIC ratio was also used to assess the fungistatic (MFC/MIC ⩾4) or fungicidal (MFC/MIC <4) effect.

We found fungicidal activity of the the oyster mushroom Pleurotus ostreatus extract and its hydrolysate against strains of the Aspergillus and Penicillium genera, with MIC ranging from 1000 to 8000 µg/mL. According to the invention, extracts obtained from P. ostreatus show strong antimicrobial activity, in particular with high fungicidal species-dependent activity against moulds of extracts obtained from the lyophilisate.

The protein-rich P. ostreatus extract and its hydrolysate can be used to produce preparations with antimicrobial activity, especially antimicrobial and antioxidant activity, including bioactive ingredients in cosmetics and anti-aging supplements or natural preservatives.

Porcine nasal microbiota constitutes a potential source of drug-resistant pathogens. Although studies have focused mainly on the Staphylococcus aureus pathogenicity, other staphylococci species also harbor antibiotic resistance determinants playing an important role in drug-resistance development. We aimed at determining the species profile of staphylococci isolated from porcine nasal microbiota and at evaluation of their antimicrobial susceptibility.

Nasal swabs were collected from 50 pigs from one age group located on a single farm in Poland. After plating, colonies with distinct morphology were isolated and identified with the use of the Vitek 2 Compact System. The antimicrobial resistance was determined with the use of automatic or disc diffusion method against oxacillin, gentamycin, linezolid, daptomycin, teicoplanin, vancomycin, tetracycline, tigecycline, rifampicin, trimethoprim/sulfamethoxazole, and tobramycin.

In total, we identified 71 strains of staphylococci represented by 12 different species: S. equorum (36.6%), S. xylosus (16.9%), S. chromogenes (14.1%), S. arlettae (7%), S. lentus (4.2%), S. hyicus (4.2%), S. kloosii (4.2%), S. simulans (4.2%), S. gallinarum (2.9%), S. saprophyticus (2.9%), S. haemolyticus (1.4%) and S. carnosus ssp. carnosus (1.4%). Among 42 (84%) pigs colonized with the above-mentioned staphylococci, 21 (50%) were colonized by one strain, 13 (30.1%) by two strains, and 8 (19.1%) by three strains. We detected resistance against tetracycline (70.4%), oxacillin (29.6%), rifampicin (9.9%), tobramycin (4.2%), and linezolid (1.4%).

The high share of resistance to tetracycline and oxacillin in staphylococci from porcine nasal microbiota is alarming and requires further investigation of the resistome.

Foodborne illnesses are a serious health problem worldwide due to the increasing bacterial resistance to antibiotics. Bacteriophages or simply phages (viruses that only infect bacteria) have been recognized for their effectiveness in controlling bacterial pathogens in the food industry. Phages exhibit important characteristics that make them promising antibacterial candidates, such as their ubiquity, high specificity against a target host, ability to self-replicate in the presence of the host, low toxicity and easy and economical isolation and production. Since Escherichia coli is one of the most important foodborne pathogens, the objective of this work was to evaluate the effectiveness of the phT4A phage (strain specific) in the inactivation of E. coli in ham. The inactivation of E. coli was first evaluated in vitro in Tryptic Soy Broth (TSB) with a reduction of about 6 log of colony forming units per milliliter (CFU/mL) for all tested values of multiplicity of infection (MOI, number of phages per bacterium), namely MOI 1, 10, 100 and 1000. In ham, a maximum reduction of about 2 log CFU/mL was obtained after 24 h (MOI of 100 and 1000). The inactivation results obtained in the ham compared to those obtained in vitro can be explained by the greater complexity of the ham matrix compared with the liquid medium TSB. Even so, the results are very promising, and the use of phages can be considered as a sustainable approach to improve food safety, namely ham, and thus prevent the infectious diseases that can arise from the ingestion of contaminated food.

The authors are grateful for financial support to CESAM by FCT/MCTES (UIDP/50017/2020 + UIDB/50017/2020 + LA/P/0094/2020) and to CICECO - Institute of Materials of Aveiro (UIDB/50011/2020, UIDP /50011/2020 & LA/P/0006/2020), funded by national funds through FCT/MEC (PIDDAC). Márcia Braz thanks FCT for her doctoral scholarship (2020.06571.BD). Carla Pereira is supported by a Junior Research contract (CEEC Individual/03974/2017). Thanks also to the Department of Biology and University of Aveiro, where this research work was carried out.

Steady increases in bacterial resistance resulting from overuse of antibiotics have become a critical global healthcare problem. Membrane-targeting antimicrobials offer a potential solution to circumvent this problem because they act on the bacterial membrane rather than any specific biosynthetic or enzymatic activity. However, the development of such molecules is hindered due to the lack of molecular principles and poor understanding of the action mechanism of the membrane targeting antimicrobial. Here we show the development of a pharmacophore model for rational design of membrane targeting antimicrobials using a combination of in silico simulations and experimental validations. The pharmacophore model consists of three fragments: one large hydrophobic scaffold, two cationic groups and two linker groups. By fine-tuning the chemistry of the fragments, we have obtained a series of compounds that act on the bacterial membrane. These compounds showed excellent activity against Gram positive bacteria, including MRSA. These compounds also displayed synergy with outer membrane permeabilizers against Gram negative bacteria. For example, the combination of one of the compounds LC100 with colistin can effectively kill colistin resistant bacteria mcr-1. Biophysical experiments showed that the combination of LC100 and colistin can break up the outer and inner membranes of mcr-1, while either LC100 or colistin along does not work. The pharmacophore model provides a useful tool for practical design of membrane targeting molecules and to tackle the issue of antimicrobial resistance.

The conventional dressings used nowadays present a passive action against microorganisms. Here, a multifunctional sandwich-like system was proposed and examined for its potential in control CW infections. The scaffolding system was made of three layers: (outer) fibrous mat of polycaprolactone (PCL) working as a barrier for preventing other microorganisms from reaching the wound bed, and was prepared at 14% w/v in chloroform/dimethylformamide (CHF/DMF) at 90/10% v/v (4 h at 50ºC); (middle) sodium alginate (SA) hydrogel loaded with the antibiotic, ampicillin (Amp), examined against Staphylococcus aureus and Escherichia coli using the broth micro-dilution assay (determination of minimum inhibitory concentration or MIC), and used to maintain a moisture environment and absorb exudates. The hydrogel was obtained by solvent casting-phase inversion method using a 2%w/v SA solution load with Amp at MBC (6,4 µg/mL) and coagulation bath of 2%w/v CaCl₂. Finally, (inner) a second fibrous mat composed of PCL and polyethylene glycol (PEG), also examined against S.aureus e E.coli (MBC of 256 µg/mL), was used to facilitate cell integration and recognition and reduce mat hydrophobicity. Mats were produced via electrospinning (12kV, 0.7mL/h, 17cm, 18G). The sandwich-like system was generated by pouring the hydrogel solution onto a casting mold lined with the inner layer and depositing the outer layer at the top of the viscous solution. After 1h of intimate contact, the casting solution was added and afterwards the scaffolding system was ready and totally detached from the mold. Data reports the effectiveness of this sandwich-like system for potential applications in CW care.

Background: The emergence of antimicrobial resistance is posing a global challenge for human health. Opportunistic Candida species have developed resistance to a wide range of antifungals. The increasing clinical prevalence of multidrug-resistant Candida species such as C. glabrata highlights the potential for fungi to pose a serious future threat if we fail to steward and deploy novel antifungal treatments. Moringa oleifera is a native Indian tree belonging to Moringaceae family, commonly known as “drumstick” or “horseradish” tree M. oleifera leaves contain b-carotene, vitamin E, and protein and its seeds contain bioactive related molecules, such as flavonoid, isothiocyanates, glucosinolate, and thiocarbamate.

Aim: The current study aimed to evaluate and compare the antimicrobial efficacy of aqueous and ethanolic extract of M. oleifera leaf and seed extract against C.albicans and C. glabrata.

Methods: Aqueous and ethanolic extract of dry powdered leaves and seeds of M. oleifera was prepared and the antifungal activity of the Moringa oleifera leaf extracts was determined using agar well diffusion method. Their zones of inhibition were compared with standard antifungal, 1% clotrimazole.

Results: The zone of inhibition against C. albicans was greater for the ethanolic extract of M. oleifera seed (22mm) when compared to ethanolic M. oleifera leaf extract (19mm) and their aqueous extracts ( 13mm, 14mm respectively). The zone of inhibition against C. glabrata was more for ethanolic extract of M. oleifera seed (21mm) when compared to ethanolic extract of M. oleifera leaf extract (20mm) and their aqueous extracts ( 14mm, 13mm respectively).

Conclusion: The ethanolic extract of M. oleifera seed showed the highest antifungal activity against C. albicans and C.glabrata.

Enterobacteriaceae family, a diverse group known to cause infections in both healthcare and community settings. ESBL-producing bacteria pose a significant challenge as they exhibit resistance to commonly prescribed antibiotics. To better understand this resistance mechanism, we focused on isolating and comparing ESBL-producing bacteria from local and broiler chicken samples, as contamination through various sources exacerbates the spread of ESBL infections. Tissue samples including leg, wing, breast, thigh, neck, liver, gizzard, and kidney were collected from a Dhaka-based slaughterhouse. Microbiological analysis utilizing MacConkey agar revealed 16 strains from local chicken and 10 strains from broiler chicken samples. After organism detection test 75% & 80% Klebsiella spp. followed by 25% & 20% E. coli were detected from local chicken and Broiler chicken respectively. Further phenotypic and genotypic characterizations were conducted, and the double disk synergy test confirmed ESBL production using Ceftazidime & Cefotaxime (CAZ/CTX ± clavulanic acid). The results indicated that 50% of local chicken strains (8 out of 16) and 40% of broiler chicken strains (4 out of 10) were ESBL producers. Subsequent genetic analysis was done by ESBL-producing genes (blaCTX-M, blaTEM & blaOXA). Polymerase Chain Reaction (PCR) followed by gel electrophoresis results revealed that all of the genes present in broiler chicken, while the couple of genes present in local chicken except blaOXA. These findings underscore the potential influence of ESBL genes within the food chain on future treatment options for Gram-negative Enterobacteriaceae infections. Addressing antibiotic resistance is critical, necessitating the development of strategies to reduce antibiotic usage.

Drinking water distribution systems (DWDS) are known to harbor biofilms, even after disinfection treatments, which constitute a source of planktonic bacteria that may remain in DW delivered through a consumer's tap. Nevertheless, the presence of parabens in DW is another problem, that may affect bacterial virulence and the susceptibility to chlorine, compromising DW disinfection. This work is the pioneer in evaluating the effects of methylparaben (MP) at concentrations found in DW on biofilm characteristics (culturability, density, viability, biofilm structure, and extracellular polymeric substances – EPS composition). Biofilm tolerance to chlorine disinfection was also evaluated. From a public health perspective and trying to understand the impact of parabens on the virulence of DW bacteria, bacteria isolated from biofilms were also characterized in terms of bacterial motility and production of virulence factors (protease and siderophores production, lipase and gelatinase activity). Dual-species biofilms formed by bacteria isolated from DW (Acinetobacter calcoaceticus and Stenotrophomonas maltophilia) were grown for 7 days on polypropylene (PPL) and high-density-polyethylene (HDPE) coupons in the absence and presence of 150 ng/L and 15000 ng/L of MP. After that, biofilms were treated with free chlorine solutions at 5 and 50 mg/L for 30 min. MP (15000 ng/L)-exposed dual-species biofilms formed in PPL were significantly more tolerant to chlorine action than non-exposed counterparts, halving the logarithmic CFU/cm² reduction values. Moreover, it was found that exposure to MP potentiated the virulence of S. maltophilia through the increase of swimming motility (141%), and gelatinase (41%) and protease production (73%). Therefore, MP is a pollutant of concern, whose presence in DW can compromise chlorine efficacy and increase the virulence of DW bacteria, especially in systems containing PPL. These results contribute to the prioritization of parabens in DW, anticipating potential microbiological-related public health concerns from the presence of parabens in DW.

According to the 2021’s European Surveillance of Veterinary Antimicrobial Consumption (ESVAC) report on sales of veterinary antimicrobial agents, the data collected for the 2010-2021 period points to a significative sales reduction in over 2/3 of the countries included. Until now, a reduction of consumption to an average 96.6 mg/PCU was achieved in a premise that the average value of 59.2 mg/PCU can be reached by 2030, urging new political strategies for the next years.

However, when exploring data from countries individually for the same decade, several shortcomings in data collection are noticed. In fact, mandatory data reporting was not on equal ground between countries, using different data aggregation strategies, and several countries in multiple years recognized underreporting values.

Access to similar tools and methodologies for data collection is crucial for all European members, especially to collect and report consistent, correct, and uniform data.

Simultaneously, some gaps are observed in PCU unit system, excluding some animals such as livestock goats and pets, and being unclear in others like in aquaculture, requiring to be revised so it helps implementing the “One Health” approach.

Preventive or mitigation actions require a standardized data system allowing trust-worthy conclusions and projections. Platforms like ESVAC database are an interesting tool which can be improved and replicated allowing the analysis of the different elements of the “One Health” approach such as human and environmental data, as well as data about resistance to antimicrobial agents.

Chronic wounds (CW) are growing rapidly, affecting 1–2% of the world's population, imposing a huge burden on healthcare systems and (urgently) needing dressings capable of aiding a more effective healing process. Infection is a complex problem in CW, and it is also known that wounds with intense bleeding prevent a rapid response, often resulting in patient morbidity and mortality.

Polycaprolactone (PCL) is a synthetic, biodegradable, biocompatible polymer, with elastic performance and excellent mechanical properties. On the other hand, sodium alginate (SA) is also a biocompatible, biodegradable and non-toxic polymer capable of retaining large amounts of water. Here, a flexible and non-adhesive fibrous structure (made of hydrophobic components that limit blood loss), easily recognized by the skin's extracellular matrix (which fibrous architecture is organized in a similar way), and loaded with hemostatic agents (carbon nanofibers, CNFs) and antibiotics (ceftazidime), was engineered for overcoming the previous problems and promote rapid blood clotting, and consequent tissue regeneration.

Wet-spun coaxial fibers were produced with a shell made of 10 wt.% PCL modified with CNFs (50, 100, 150 μg/mL) and a core of 2 wt.% SA loaded with Ceftazidime (128 μg/mL) using a 2 wt.% CaCl₂ coagulation bath. The coaxial structure was confirmed via brightfield microscopy, and the elements composing the fibers were detected by Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analyses (TGA). Antimicrobial testing was conducted against Staphylococcus aureus and Pseudomonas aeruginosa revealing great efficacy over a period of 24h. The ability of the fibers to induce blood coagulation was verified using recalcified plasma. In the end, the coaxial fibers were identified as potentially effective for CW care.