Introduction:

Short cationic peptides are valuable chemical templates for the design of clinically available antibiotics. The discovery and development of these peptides face numerous challenges, including time-consuming screening processes, toxicity, and stability issues. Computational methods have been integrated into this process, with successful outcomes.

Methods:

In this study, we designed eight arginine-rich peptides, which were analysed using in silico tools to predict their toxicity and antimicrobial properties. We then confirmed the in vitro antibacterial effects and toxicity to fibroblasts and red blood cells of these synthetic peptides using absorbance-based assays. The activity of these peptides was also tested in environments that were rich in proteases. Three chemically modified peptides were synthesised based on the most active peptide. The antibiofilm action and bactericidal effects were evaluated using fluorescent markers and microscopy. We also monitored the levels of reactive oxygen species (ROS) when the peptides were incubated with bacteria.

Results:

In summary, we observed discrepancies between the in silico predictions and the in vitro screening results. R4F4 was the most promising peptide candidate, but its function was impaired when incubated with serum or trypsin. The lipidated analogue was toxic and did not exhibit similar antimicrobial effects. However, cyclisation and D-amino acid substitution strategies enhanced the stability and activity of novel analogues. These arginine-rich peptides act through a dual mechanism, integrating damage to the bacterial membrane and an increase in reactive oxygen species levels.

Conclusions:

Overall, this study demonstrates the significant contributions of the cyclisation and D-amino acid substitution approaches in enhancing the stability and activity of arginine-rich peptides. It represents an important step forward in the development of peptide-based candidates, which could form the basis of future antibacterial interventions.

The massive use of azoles in agricultural and horticultural production has been described as a determining factor in the emergence of resistant strains, particularly of Aspergillus spp, which pose a significant threat to human and environmental health, according to a recent EU report under the "One Health" approach. This fact is linked to the non-medical use of azoles, according to a recent European Food Safety Authority (EFSA) report under the “One Health” approach. Approximately 120,000 tons of azoles have been placed on the market in the EU/EEA for non-medical uses, mostly as phytosanitary products, according to data analyzed between 2010 and 2021. Some compounds, such as epoxiconazole, used mainly in EU cereal, fruit, vegetables, and other crops, have proved highly resistant. However, because of regulatory advancements, the use of these compounds could be subject to a ban, which would impact the global farming sector. Environmental hotspots for resistance selection have also been identified, including the use and storage of agricultural residues and biocide-treated wood. Therefore, this systematic review aims to evaluate bio-based alternatives, assessing their efficacy, mechanisms of action, impact on harvesting, and limitations. Through a benchmark study with azoles, our work seeks to identify sustainability strategies that reduce the dependence on synthetic fungicides and promote safer and more effective agricultural practices. In addition, regulatory guidelines will be discussed to promote integrated approaches that support robust food security.

The widespread use of antibiotics in livestock has significantly contributed to the emergence and spread of antimicrobial-resistant bacteria, posing a risk for zoonotic transmission. The presence of multidrug-resistant Escherichia coli in poultry emphasizes the need for a One Health approach in monitoring antimicrobial resistance. This study aimed to determine the prevalence of E. coli in fecal samples from broilers, characterize their antimicrobial resistance profiles, and assess their genetic traits, including resistance genes, virulence factors, integrases, and phylogenetic groups.

Genomic DNA was extracted from 19 E. coli isolates obtained from broiler fecal samples collected at Savinor (Trofa, Portugal) using the boiling method. Resistance genes, integrases, virulence factors, and phylogenetic groups were identified by PCR. Only two isolates lacked resistance genes. The most prevalent gene was ampC (17/19), followed by tetA (12/19), blaCTX-M (11/19), and qnrS (7/19). Other detected genes included blaSHV, blaTEM, blaVIM, aadA1, aadA5, sul2, strB, sul1, blaIMP, and aac(3)-II. All isolates carried the fimA virulence factor, with five also harboring aer. The int1 integrase gene was found in six isolates. Phylogenetic analysis showed that 12 isolates belonged to group A, five to B1, and two to D.

This study reveals the high prevalence of antibiotic-resistant E. coli in broilers in Portugal, underscoring the importance of regional surveillance. The combined analysis of resistance, virulence factors, and phylogenetic groups provides a broader understanding of the genetic traits that may enhance zoonotic potential. Resistance was mainly observed in typically commensal phylogroups, suggesting an adaptation to selective pressure in poultry environments. Stronger antimicrobial stewardship, including restricting critically important antibiotics, promoting alternatives like probiotics and vaccination, and improving farm hygiene, is crucial. Future research should focus on tracking resistance gene mobility and transmission pathways to inform public health strategies within a One Health framework.

Introduction: The rising prevalence of carbapenem-resistant Enterobacteriaceae (CRE) poses a major public health threat, impacting the efficacy of last-resort antibiotics. In the United Arab Emirates (UAE), camels, vital to culture and the economy, may act as CRE reservoirs. However, the CRE carriage in farm animals across the UAE and Gulf Cooperation Council countries remains largely unexplored.

Objectives: This pilot study aimed to evaluate the prevalence and genetic characteristics of carbapenem-resistant Enterobacteriaceae in camels in the UAE.

Methods: Fecal samples from 12 camels on a Dubai farm were screened for carbapenem- and extended-spectrum β-lactamase-producing Gram-negative bacilli using selective culture techniques. The antimicrobial susceptibility testing followed the CLSI guidelines, while multiplex PCR was used to identify Carbapenemase genes. Whole-genome sequencing (WGS) revealed detailed genetic profiles, including the sequence types and global relatedness of the isolates. In total, 20 bacterial isolates were tested, and based on their plasmid profiles, WGS of 4 isolates was performed.

Results: CR Escherichia coli was found in 8.33% (1/12 ) of the camels. The isolates carried the blaNDM gene, conferring carbapenem resistance, but lacked the other tested Carbapenemase genes. Antimicrobial susceptibility testing showed multidrug resistance to multiple antibiotic classes. Among the four isolates, the S101-C1 isolate (the ST648 complex) displayed an extensive resistance profile, harboring blaNDM-5, blaCTX-M-15, blaOXA-1, blaTEM-1, and resistance genes for aminoglycosides (aac(6')-Ib-cr5, aadA5), sulfonamides (sul1), tetracyclines (tet(B)), and macrolides (mph(A)). Resistance was augmented by efflux-associated genes (acrF/emrD/emrE) and mutations (ftsI_N337NYRIN, gyrA_D87N/S83L). Another isolate, S101-E1 (ST155 complex), exhibited MDR, with the resistance genes blaCTX-M-15, blaTEM-1, tet(A), qnrS1 and a colistin resistance mutation (pmrB_Y358N). Efflux-related genes (acrF/mdtM) were also present.

Conclusion: This study is the first to report the presence of bla_NDM-positive E. coli in camels in the UAE, suggesting that camels may serve as reservoirs for antimicrobial-resistant bacteria, including CRE. It highlights the potential risks of zoonotic transmission through direct contact or via the food chain.

Inappropriate use of antibiotics has become a critical global health concern, significantly contributing to the rise of bacterial resistance. This alarming phenomenon represents a threat to public health, as antibiotic-resistant infections become increasingly difficult to treat and life-threatening. In 2019, bacterial antimicrobial resistance was linked to approximately 4.95 million deaths worldwide.

Dentists play a substantial role in antibiotic stewardship, as recent studies indicate that dental prescriptions account for nearly 10% of all oral antibiotic prescriptions—a percentage that has shown little to no decline over time. Prescribing patterns in dentistry often rely on empirical decision-making rather than evidence-based guidelines, leading to overuse, misuse, and inappropriate prophylactic or therapeutic antibiotic administration. This widespread mismanagement exacerbates the development of resistance, highlighting the need for evidence-based prescribing protocols and enhanced education on antimicrobial stewardship to mitigate unnecessary antibiotic use in dental settings.

To complicate the picture, chlorhexidine (CHX), the most widely used antiseptic in dentistry, is commonly applied for oral healthcare in the form of mouthwashes, toothpastes, gels, varnishes, and sprays. However, in recent decades, studies have supported its bacterial resistance to CHX across various species. The possible contribution of CHX to antimicrobial resistance through selective pressure requires thorough evaluation, and further research should investigate CHX resistance and potential cross-resistance with antibiotics in both clinical and environmental isolates.

This talk will provide a comprehensive overview of antibiotic use in dentistry and its clinical implications, including considerations regarding its combined use withCHX.

Introduction:

Biofilms are complex microbial communities that form on biotic and abiotic surfaces within livestock farming environments. Within biofilms, bacteria can efficiently exchange genetic material, including antimicrobial resistance genes (ARGs), potentially serving as reservoirs and amplifiers of antimicrobial resistance (AMR). This scoping review aimed to summarize the current knowledge on AMR, ARGs, and antimicrobial residues (ARs) in biofilms from poultry, swine, and cattle farms.

Materials and methods:

This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. Four databases (PubMed, Scopus, Web of Science, and Agricola) were searched using relevant keywords. Peer-reviewed studies assessing AMR, ARGs, and ARs in farm environment biofilms were eligible for inclusion. The identified studies were imported into Zotero for deduplication and subsequently screened in Rayyan in two phases (title/abstract and full text). Data from the included studies were extracted and charted using an ExcelⓇ 2016 spreadsheet.

Results:

A total of 1,242 studies were identified across the databases. After deduplication and title/abstract screening, 52 studies proceeded to the full-text screening, with only 4 meeting the eligibility criteria. The included studies were published between 2021 (n =1) and 2022 (n= 3) and originated from Germany, India, and Iran. Two of these studies focused on broiler farms, one on layer farms, and one on dairy cow farms. Among the four studies, three conducted antimicrobial susceptibility testing, one investigated ARGs, and none reported on ARs from biofilm isolates.

Conclusion:

This scoping review reveals a significant gap in the scientific evidence regarding AMR, ARGs, and ARs in biofilms from livestock farms and emphasizes the need for further research to clarify their role in the spread of AMR in the livestock sector.

Staphylococcus aureus (S. aureus) is a pathogenic bacterium capable of colonizing human and animal hosts while persisting on environmental surfaces. Due to its ability to spread via direct and indirect transmission, it poses a major risk for food contamination, necessitating stringent hygiene control throughout food storage, processing, and distribution.

This study aimed to detect the S. aureus contamination in raw beef and surface swabs from meat markets and assess antibiotic resistance. A total of 372 samples were analyzed: 160 from a meat processing plant and 212 from meat markets. S. aureus was identified using polymerase chain reaction (PCR) targeting the nucA gene, following the ISO 6888-1:2021 standards. Antibiotic susceptibility was assessed using the Kirby–Bauer disk diffusion method, with the results interpreted according to the CLSI M100-S27 guidelines. Resistance genes (mecA, mecC, vanA, and vanB) were detected using PCR.

No S. aureus was detected in the meat processing plant samples. However, 31.3% of the raw beef and 17.3% of the surface swabs from markets tested positive. The isolates from the raw beef exhibited the highest resistance to oxacillin, ampicillin, and penicillin. Over 50% of the surface swab isolates demonstrated resistance to oxacillin, tetracycline, azithromycin, and clindamycin. The mecA gene was found in 24.4% of the raw meat isolates and 35.7% of the surface swab isolates, whereas vanA, vanB, and mecC were not detected.

The high prevalence of S. aureus contamination and antibiotic resistance in meat markets presents potential public health risks. These findings emphasize the need for improved food safety measures, strict hygiene regulations, and responsible antibiotic use. Continuous surveillance and novel therapeutic strategies are essential for mitigating the risks associated with antibiotic-resistant bacteria.

Abstract

Introduction : Acinetobacter bereziniae IJ5 is a Gram-negative bacterium notorious for multidrug resistance and poses a significant risk for nosocomial infections. This study focuses on the genomic characterization of A. bereziniae strain IJ5, recovered from drinking water in Dhaka, Bangladesh. Through comparative genome analysis with other global strains, we determine its pathogenicity, virulence, and adaptation strategies.

Methods: The genome of A. bereziniae was sequenced using Illumina MiniSeq, followed by assembly with Shovill on Galaxy and annotation through RAST and PGAP in NCBI. The bioinformatics analyses carried out revealed antibiotic resistance genes, virulome, toxin–antitoxin systems, secondary metabolites, and prophage sequences, with the goal of identifying the factors that contribute to its pathogenicity.

Result : A unique combination of MDR genes such as qacG, adeF, OXA-355, and vanG was identified, coupled with diverse toxin–antitoxin systems consisting of RelE/RelB, ParE/ParD, and HigB/HigA, underscoring the high survival capability of IJ5. The genome of A.bereziniae IJ5 has a GC content of 38% and a total size of 4.4 Mb. The presence of distinct metabolic pathways, such as Ni-siderophores, RiPP-like compounds, and arylpolyenes, contributes to the resilience of IJ5 in clinical environments. IJ5’s pathogenicity score of 77.2% indicates a strong potential to infect humans, enhanced by regulatory
elements. IJ5 is closely related to the AB839 (Taiwan) and FFMG-36-12-21 (Tanzania) strains of A. bereziniae, as they share a common ancestor; additionally no other strains cluster with IJ5, portraying its unique sub-lineage.

Conclusion: The genomic analysis of A. bereziniae reveals a distinctive mixture of MDR genes and toxin–antitoxin systems, showing an enhanced adaptability in clinical settings. A high pathogenicity score of 77.2% indicates strong infection potential, likely reinforced by regulatory elements. Comparative analysis further shows the genomic plasticity and persistence of IJ5, highlighting the necessity for continuous surveillance and research to develop targeted infection control and treatment strategies within Bangladeshi healthcare facilities.

Introduction: Chronic bronchitis is a significant public health concern, often leading to recurrent exacerbations and impaired lung function. Effective antibiotic therapy is crucial to manage bacterial infections that exacerbate symptoms. Gemifloxacin, a broad-spectrum fluoroquinolone, and Amoxicillin/Clavulanate, a beta-lactam/beta-lactamase inhibitor combination, are commonly prescribed antibiotics for respiratory tract infections. This study evaluates the therapeutic efficacy and safety of Gemifloxacin versus Amoxicillin/Clavulanate in chronic bronchitis patients.

Method: A randomized open-label clinical trial was conducted on patients diagnosed with chronic bronchitis experiencing acute exacerbations. During the study period, a total of 102 patients were enrolled in this study. Of these, 33 patients were in the Gemifloxacin 320 mg group and 35 patients were in the Amoxicillin/Clavulanate 625 mg group, whereas 34 were in the Amoxicillin/Clavulanate 1 gram group, based on the inclusion and exclusion criteria. During the study period, three patients were excluded from the Gemifloxacin 320 mg group, five patients were excluded from the Amoxicillin/Clavulanate 625 mg group, and four patients were excluded from the Amoxicillin/Clavulanate 625 mg group due to a lack of exact information. The data of the remaining 90 patients—30 patients in each group—were analyzed. Clinical symptoms, X-ray, PFT (FVC, FEV1, FEF, (FEV1/FVC), and bacteriologic assessments were performed for all patients.

Results: Both Gemifloxacin and Amoxicillin/Clavulanate (625 mg and 1 gm) effectively reduced symptoms and improved lung function. The bacteriological success rate was found to be better in the Gemifloxacin 320 mg group compared with the Amoxicillin/Clavulanate 1 gram and Amoxicillin/Clavulanate 625 mg groups.

Conclusion: Gemifloxacin 320 mg offers an effective alternative to Amoxicillin/Clavulanate 1 gram and Amoxicillin/Clavulanate 625 mg in the treatment of chronic bronchitis. The incidence of side effects was found to be lower in Gemifloxacin 320 mg, suggesting better tolerability when compared with Amoxicillin/Clavulanate 1 gram and Amoxicillin/Clavulanate 625 mg.

Introduction: The Flavin mononucleotide riboswitch (FMN riboswitch) is the second most prevalent riboswitch, presented in more than 4300 bacterial species. Sensing FMN, it regulates the synthesis of vital cellular metabolites in Staphylococcus aureus (S. aureus) and seven more pathogenic bacteria included in the priority list of the World Health Organization important for combating antimicrobial resistance. The following study presents the process of the rational design of an antisense oligonucleotide (ASO) with bacteriostatic effects targeting the FMN riboswitch in S. aureus.

Methods: The rational design of ASO, targeted to the multidrug-resistant bacterium S. aureus, is based on bioinformatics and genomic studies, encompassing the following: an analysis of international databases, Clustal X multiple alignments, a selection of appropriate motifs, BLAST analysis in human, probiotic, and other pathogenic bacteria, biochemical pathways, and RNA folding analysis (MFE and PF).

Results: The bioinformatics study results show how the FMN riboswitch is highly suitable for ASO design, as it controls the expression of the fmnP gene in S. aureus (FMN transporter) by translation prevention, and the ribD operon (enzymes for FMN synthesis) by transcription termination. This allows us to design an ASO, which is recognized by both the riboswitch responsible for FMN synthesis and the one for the transporter protein. Its bacteriostatic effect in S. aureus is observed in 700nM, 4.5 μg/mL. Cytotoxicity tests confirm that it is not inherent in the human cell lining of non-small cell lung cancer A549 at this concentration.

Conclusions: Since FMN is not presented in the human genome and regulates the synthesis and transport of essential proteins for the survival and division of bacterium metabolites, it provides the potential as target for designing antibacterial drugs against the most severe human pathogenic bacteria. Our proprietary bioinformatics protocols for suitability and for ASO design allow us to introduce novel ASO as potential effective antimicrobial therapeutic with a growth inhibitory effect in S. aureus.