Search Results (482)

Background: Antibiotic resistance is a significant health problem in healthcare settings, especially intensive care units (ICUs), where patients are critically ill. This study aims to identify the bacterial profile and antibiotic resistance patterns of Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter, and Escherichia coli (ESKAPEE) in blood specimens collected from adult patients admitted to the ICUs of public hospitals in Abu Dhabi, United Arab Emirates. The World Health Organization lists these pathogens as priority pathogens that greatly threaten humans. Methods: This cross-sectional study used routinely collected data through the AMR surveillance system between 2018 and 2022. Results: A total of 838 culture-positive blood specimens were reported during the study period, and 965 ESKAPEE pathogens were isolated. The most frequently isolated bacteria were Klebsiella pneumoniae (31%), Escherichia coli (22%), and Staphylococcus aureus (20%). Acinetobacter baumannii exhibited high resistance to Amikacin (81%), Meropenem (72%), and Imipenem (87%). Escherichia coli demonstrated resistance to Imipenem (42%) and Cefotaxime (54%). Klebsiella pneumoniae showed resistance to Imipenem (37%) and Cefotaxime (39%). Staphylococcus aureus showed resistance to Penicillin G (80%), Oxacillin (4%), and Ciprofloxacin (54%). Conclusions: The study showed a high prevalence of resistance in the most frequently isolated ESKAPEE pathogens in adult ICU patients. This brings into focus the need for appropriate infection control measures and strong antibiotic stewardship programs. The findings of the study support the ongoing efforts to deploy a better diagnostic tool for rapid pathogen identification, which is key in the targeted management of patients with bloodstream infection, especially in ICUs. Full article

Antimicrobial resistance (AMR) is one of the most critical challenges to global public health in the 21st century, posing a significant threat to healthcare systems and human health due to treatment failure and high mortality. The World Health Organization (WHO) estimates that, without effective interventions, AMR-associated infections could cause 10 million deaths annually and economic losses of up to 100 trillion US dollars by 2050. The rapid spread of drug-resistant strains, especially in hospital and community settings, has significantly reduced the efficacy of traditional antibiotics. With the continuous advancements in relevant research, bacteriophage (Phage) therapy is constantly innovating in the antimicrobial field. The application of frontier technologies, such as phage cocktails and engineered phages, has significantly enhanced the broad spectrum and high efficiency of phage therapy, which is gradually becoming a new generation of tools to replace antibiotics and effectively combat pathogenic bacteria. However, phage therapy is facing several challenges, including phage inactivation by gastric acid, enzymes, ultraviolet light, and mechanical stress, as well as the potential risk of bacterial phage resistance. Advanced encapsulation technologies such as electrospun fibers, liposomes, chitosan nanoparticles, and electrospray provide solutions to these problems by protecting phage activity and enabling controlled release and targeted delivery. This review addresses phage therapeutic studies of Salmonella, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, and Listeria monocytogenes, summarizes the recent advances in phage research, and details the current development and applications of encapsulated phage technologies across various delivery modes. Full article

The rising resistance of bacterial and fungal strains, particularly in biofilm form, is diminishing the efficacy of available therapies and poses a major threat to human health. This highlights the need for new antimicrobial agents. A review of biological studies has shown that 2,7-naphthyridine derivatives exhibit a wide spectrum of pharmacological properties, including antimicrobial activity, which has contributed to the development of new compounds containing this scaffold. In this work, the obtained compounds were tested to assess their ability to eradicate biofilm formed by selected reference strains of opportunistic pathogens: Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans as well as towards normal microbiota representative, referred to as the Lactobacillus crispatus. The tested 2,7-naphthyridine derivatives showed selective antimicrobial activity, exclusively against S. aureus. 10j demonstrated the highest, among tested compounds, activity on this pathogen (MIC = 8 mg/L), while compound 10f exhibited ~100-fold stronger activity (MIC = 31 mg/L) than the majority of the library compounds. The in vitro assessment on fibroblast cell lines demonstrated low cytotoxicity of both compounds 10f and 10j, which was subsequently confirmed in vivo using the Galleria mellonella larval model, where no signs of systemic toxicity were observed during the 5-day observation period. Due to the structural similarity of the compounds 10f and 10j to typical gyrase/topoisomerase IV inhibitors, molecular dynamics simulations were performed on a ternary complex containing protein, DNAds, and a 1,5-naphthyridine inhibitor (PDB ID: 6Z1A). Molecular dynamics of the gyrase–DNA ternary complex supported stable binding of both hydrazone derivatives, with 10j showing slightly more favorable MM/GBSA energetics driven by electrostatics and halogen bonding, consistent with its ~4-fold lower MIC versus 10f. Taken together, our data highlight compound 10j as a promising microbiota-sparing antibacterial candidate, particularly suitable for selective interventions against S. aureus, for instance in vaginal infections, where targeted eradication of the pathogen without disturbing protective commensals is highly desirable. Full article

Pseudomonas aeruginosa is an opportunistic pathogen commonly associated with infections in hospitalized and immunocompromised patients due to its virulence and antimicrobial resistance. In the poultry industry, it has been associated with hatchery mortality. This study aimed to characterize P. aeruginosa isolated from pipped eggs, one-day-old chicks, and broiler carcasses obtained from a slaughterhouse in São Paulo state, Brazil. Nineteen strains of P. aeruginosa were selected and their virulence genes were amplified via PCR. Clonality analysis was performed using BOX-PCR, and three strains were selected for whole-genome sequencing (WGS). All isolates carried aprA, plcH, plcN, lasA, lasB, lasI, lasR, rhlAB, and phzH. The exoA gene was detected in 73.7% of strains, while algD was present in 21.1%. The exoY and exoT genes were present in 94.7% of strains (18/19), whereas exoS was present in 47.4% (9/19). None of the isolates harbored the exoU gene. BOX-PCR and phylogenetic analyses revealed diverse clonal patterns. The sequenced strains were classified as O3 ST116, O2 ST1649, and O3 ST1744. The presence of virulence and antimicrobial resistance determinants in poultry-associated strains underscores the need for surveillance, as these isolates may represent a source for transmission of P. aeruginosa to humans. Our findings highlight the importance of monitoring P. aeruginosa within poultry production and emphasize the value of genomic approaches to understand its diversity, evolution, and public health risks. Full article

Antimicrobial resistance (AMR) poses a critical global health challenge, with carbapenemase-producing Enterobacterales (CPE) representing one of the most urgent threats. While Klebsiella pneumoniae and Escherichia coli have been the focus of most surveillance programs, Enterobacter spp., members of the Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp., and Escherichia coli (ESKAPEE) group, remain an underrecognized but increasingly important reservoir of carbapenemase genes in Europe. Despite being categorized by the World Health Organization (WHO) as “critical-priority” pathogens, Enterobacter spp. are largely excluded from major AMR surveillance frameworks, creating blind spots in detection and control. This review summarizes the taxonomy, intrinsic resistance mechanisms, and clinical relevance of Enterobacter spp., with a particular focus on carbapenemase epidemiology across Europe. We highlight the distribution and genetic context of major carbapenemases, including VIM, OXA-48-like, KPC, and NDM, and discuss emerging or minor enzymes such as IMI, FRI, GES, and IMP. Epidemiological data reveal shifting dominance patterns over time, with VIM enzymes consolidating their prevalence after 2015, while OXA-48-like and KPC declined, and NDM gained ground. The genetic diversity of Enterobacter spp., coupled with their ability to act as both nosocomial pathogens and silent intestinal or environmental reservoirs, facilitates the dissemination of carbapenemase genes via epidemic plasmids and clonal expansion. Addressing the growing impact of carbapenemase-producing Enterobacter spp. requires their systematic inclusion in national and international monitoring programs, expanded use of genomic epidemiology in clinical microbiology, and better alignment between research, clinical practice, and policy. A One Health approach is essential to curb the spread of carbapenemases across human, environmental, and animal reservoirs, and to safeguard the remaining therapeutic options. Full article

Background/Objectives: Antimicrobial resistance is a critical global health challenge. Among resistant pathogens, the group of bacteria collectively referred to as ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) is of particular concern due to their ability to evade multiple classes of antimicrobials. This study aimed to investigate the occurrence and resistance patterns of ESKAPE bacteria in wild birds from Northern and Central Italy sites, and to assess the presence of other bacteria of public health relevance. Methods: Cloacal swabs were collected from 141 wild birds. Samples were processed on selective and differential media, and bacterial identification was performed using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry. Antimicrobial susceptibility was evaluated through Minimum Inhibitory Concentration assays and interpreted according to international guidelines. Results: Thirty-seven isolates belonging to the ESKAPE group were identified: E. faecium (n = 10), K. pneumoniae (n = 9), P. aeruginosa (n = 8), Enterobacter spp. (n = 7), S. aureus (n = 2), and A. baumannii (n = 1). Multidrug-resistant isolates were observed among K. pneumoniae and Enterobacter hormaechei. Escherichia coli, although not included in the ESKAPE group, was frequently detected and often co-isolated with clinically relevant bacteria, highlighting its potential role as a reservoir of resistance genes. Conclusions: Wild birds can harbor resistant bacteria of clinical importance, including multidrug-resistant ESKAPE species. Their presence in avian populations underscores the role of wildlife in the environmental dissemination of antimicrobial resistance, with implications for both animal and human health. Full article

Bacteriophages have been widely investigated as a promising treatment of food, medical equipment, and humans colonized by antibiotic-resistant bacteria. Phages pose particular interest in combating those bacteria which form biofilms, such as the medically important human pathogen Pseudomonas aeruginosa and several plant pathogens, including P. syringae. In an undergraduate lab course, P. putida was used as the host to isolate novel anti-pseudomonal bacteriophages. Environmental samples of soil and water were collected, and purified phage isolates were obtained. After Illumina sequencing, genomes of these phages were assembled de novo and annotated. Assembled genomes were compared with known genomes in the literature and GenBank to identify taxonomic relations and to refine their functional annotations. The thirteen phages described are sipho-, myo-, and podoviruses in several families of Caudoviricetes, spanning several novel genera, with genomes ranging from 40,000 to 96,000 bp. One phage (DDSR119) is unique and is the first reported P. putida siphovirus. The remaining 12 can be clustered into four distinct groups. Six are highly related to each other and to previously described Autotranscriptaviridae phages: Waldo5, PlaquesPlease, and Laces98 all belong to the Waldovirus genus, whereas Stalingrad, Bosely, and Stamos belong to the Troedvirus genus. Zuri was previously classified as the founding member of a new genus Zurivirus within the family Schitoviridae. Ebordelon and Holyagarpour each represent different species within Zurivirus, whereas Meara is a more distantly related member of the Schitoviridae. Dolphis and Jeremy are similar enough to form a genus but have only a few distant relatives among sequenced phages and are notable for being temperate. We identified the lysis cassettes in all 13 phages, compared tail spike structures, and found auxiliary metabolic genes in several. Studies like these, which isolate and characterize infectious virions, enable the identification of novel proteins and molecular systems and also provide the raw materials for further study, evaluation, and manipulation of phage proteins and their hosts. Full article

Pseudomonas aeruginosa is an opportunistic pathogen of public health concern. This study aimed to investigate the prevalence of P. aeruginosa, some virulence factors, and antimicrobial resistance patterns and highlight the potential pathways of horizontal bla_SHV-resistant gene transfer from diverse sources. A total of 220 samples were collected from fish (n = 90), water (n = 30), poultry (n = 50), and humans (n = 50). All samples were isolated, confirmed by the Vitek 2 system, and tested against antimicrobial agents. Some virulence and resistance genes were examined by PCR and sequenced for the bla_SHV-resistant gene from four selected isolates from each source. SPSS v26, with chi-squared tests and Pearson correlations (p < 0.05), was implemented for statistical investigation. P. aeruginosa was isolated at 33.3%, 20%, 14%, and 24% from fish, water, poultry, and humans, respectively. Using the diffusion disk method, extensively drug-resistant (XDR) and multidrug-resistant (MDR) strains were detected. All strains harbored the oprL and toxA genes, while the lasB gene was present in 40% of fish samples but not present in human samples. All strains lacked the exoS gene. The tetA, sul1, bla_SHV, and bla_TEM resistance genes were detected at different percentages. The bla_SHV genes from fish and water isolates were closely related to each other and showed similarity to those of the human isolates. The poultry isolates formed a separate phylogenetic lineage. The emergence of XDR and MDR P. aeruginosa highlights a possible public health threat. Based on the gene similarity between fish and water isolates, our results suggest that these isolates have a common origin. The similarity between the human isolates and environmental isolates (fish and water) raises concerns about possible transmission to humans. Full article

Controlling bacterial growth and biofilm formation remains a major challenge in the treatment of chronic wounds and in preventing infection after biomedical device implantation. Thus, creating materials with inherent antibacterial potential is necessary. Here, we report silk fibroin–polyethylenimine-based (SF-PEI) microparticles to control the growth of Pseudomonas aeruginosa, which is a highly infectious and biofilm-forming pathogen. SF-PEI microparticles were fabricated using a solvent displacement method, and their microparticle formation was confirmed using Fourier-transform infrared spectroscopy (FTIR). The morphology and size of the microparticles were characterized using scanning electron microscopy (SEM) and dynamic light scattering (DLS). The SEM and DLS methods revealed that the microparticles formed showed a uniform, spherical morphology with a consistent size distribution, showing a Z-average of 834.82 nm. The antibacterial and biofilm inhibition properties of the SF-PEI microparticles were tested against P. aeruginosa. The results show significant control of bacterial growth and biofilm formation when treated with the SF-PEI particles. Further, a cell viability assay was evaluated using human dermal fibroblasts, and the results demonstrated that the SF-PEI microparticles developed demonstrated cytocompatibility, with no significant cytotoxic effects observed. These results suggest that SF-PEI microparticles offer a promising biocompatible strategy for reducing bacterial growth and their biofilm-associated infections, particularly in wound healing and medical device applications. Full article

The growing demand for natural and sustainable food preservatives has drawn interest in carbon dots (CDs) derived from plant sources. This study aimed to synthesize CDs from dried German chamomile flowers (DF) and residual biomass (RB) obtained after essential oil extraction using a hydrothermal process. Their characteristics, bioactivities and cytotoxicity were examined. Both DF-CDs and RB-CDs were spherical (7–10 nm), exhibited strong UV blocking properties and tunable fluorescence and were rich in polyphenolic functional groups, especially the –OH group. DF-CDs generally showed higher antioxidant capacity than RB-CDs as assayed by DPPH, ABTS radical scavenging activities, FRAP and metal chelation activity. Both CDs showed antibacterial effects toward pathogenic bacterial strains (Escherichia coli and Listeria monocytogenes) and spoilage bacteria (Shewanella putrefaciens and Pseudomonas aeruginosa) in a dose-dependent manner. Cytotoxicity was assessed in BJ human fibroblasts, and both CDs exhibited high biocompatibility (>88% viability at 1000 µg/mL). When both CDs at 300 and 600 ppm were applied in a precooked baby clam edible portion (PBC-EP) stored at 4 °C, microbial growth, TVB and TMA contents were lower than those of the control. The total viable count was still under the limit (5.8 log CFU/mL) for the sample treated with CDs at 600 ppm up to 9 days, while the control was kept for only 3 days. Furthermore, the lipid oxidation level (PV and TBARS value) of PBC-EP decreased with CD treatment, especially at higher concentrations (600 ppm). Therefore, chamomile-derived CDs could serve as a promising alternative for perishable seafood preservation. Full article

Antimicrobial-resistant bacteria (ARB) in the ESKAPE group include Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. These pathogens continue to pose a global threat to human health. Urban and non-urban rivers affected by anthropogenic activities such as farming can act as reservoirs for ARB. The influx of wastewater from animal farms and irrigation processes can affect the normal microbiota in surrounding waterbodies. New bacteria, such as those in the ESKAPE family, may be introduced into these waterbodies, since most ESKAPE pathogens are domiciled in humans and animals. There is a dearth of information on the persistence of ESKAPE isolates and their associated health hazards in non-nosocomial settings. Therefore, this review aimed to collect data on the global distribution of ESKAPE pathogens in aquatic systems. PubMed and Google Scholar were searched for articles published from 2009 to 2025. A total of 76 studies published in peer-reviewed journals were included. Data were collected from 21 papers for E. faecium/faecalis, 12 for S. aureus, 15 for K. pneumoniae, 11 for A. baumannii, 8 for P. aeruginosa, and 9 for Enterobacter spp. The findings in this review will increase public health awareness on the significance of ESKAPE pathogens in aquatic systems. Full article

Background/Objectives: Resistance of pathogenic microorganisms to antibiotics poses a serious threat to public health and often leads to devastating consequences. In this context, one of the pressing challenges in pharmacochemistry is the search for new, effective antibiotics to combat severe human diseases. Cyclic lipopeptides have emerged as some of the most promising candidates and have been widely studied. These compounds are a class of microbial secondary metabolites produced by various microorganisms, and they possess significant medical and biotechnological importance. The defining structural feature of these compounds is the presence of both a hydrophobic fragment, primarily a hydrocarbon tail of varying length, and a hydrophilic cyclic peptide moiety. This hydrocarbon tail confers amphiphilic properties to the lipopeptides, which are essential for their broad spectrum of biological activities. Their mechanism of action involves disruption of the cell membrane, and in many cases, the formation of ion-permeable defects has also been shown. Results: This review summarizes the data on cyclic lipopeptides produced by Pseudomonas spp., Streptomyces spp., and Bacillus spp. that modify membrane permeability through the formation of ion channels. The main emphasis is on understanding how the structure of the CLP can be related to the probability and mode of pore formation. Conclusions: The findings can contribute to expanding the arsenal of effective antimicrobial agents with a mechanism of action that reduces the risk of developing resistance. Full article

Bacterial diseases are widespread in pet birds, posing a severe threat in nestlings and birds with weakened immune systems, often resulting in high mortality during the first days after hatching. This study aimed to describe the pathological findings of a natural bacterial co-infection with Klebsiella pneumoniae and Pseudomonas aeruginosa in nestling European goldfinches (Carduelis carduelis), as a cause of mortality after hatching. Eight nestlings kept in a breeding facility showed an inability to move, anorexia, and respiratory distress, and were found dead between 1 and 4 days of life. Gross pathological findings included diffuse pneumonia with edema and multifocal hemorrhages and occasionally hepatic necrosis. On histopathology, the main findings in all examined birds included severe, subacute bronchopneumonia and severe necrotizing hepatitis. Gram-negative bacilli were observed in parabronchial walls, within pulmonary arteries and surrounding hepatocellular necrotic foci. Lungs, livers and kidneys were sampled for bacteriological examination, resulting in two Gram-negative bacterial isolates. Four housekeeping genes (i.e., 16S rRNA; rpoB; khe; ecfX) were amplified and sequenced for bacterial identification at species level. Although K. pneumoniae and P. aeruginosa are common Gram-negative pathogens and are often co-isolated in human bacterial pneumonia, co-infection with these bacteria has not been documented in nestling goldfinches to date. Pathogen identification is essential for formulating a correct etiological diagnosis and further selecting the most appropriate therapeutic strategy. Full article

Antimicrobial resistance (AMR) is a growing global health threat, with wild birds increasingly recognized as potential reservoirs of resistant pathogens and as sentinels of environmental AMR. This study investigated the occurrence and AMR profiles of Gram-negative bacteria isolated from wild birds that died at the Wildlife Rescue Center in Vanzago, Lombardy, in 2024. Cloacal swabs were collected from 112 birds representing various ecological categories. A total of 157 Gram-negative bacteria were isolated and identified, including clinically relevant genera and species, such as Escherichia coli, Klebsiella pneumoniae, Enterobacter spp., Salmonella spp., Pseudomonas aeruginosa, and Acinetobacter baumannii. Antimicrobial susceptibility testing revealed resistance to first-line and critically important antimicrobials, including those exclusively authorized for human use. Notably, a phenotype compatible with Extended-Spectrum Beta-Lactamase (ESBL) production was detected in four out of ten (40%) K. pneumoniae isolates. In addition, 20 out of the 157 (12.7%) isolated bacteria phenotypically exhibited a resistance profile indicative of AmpC beta-lactamase (AmpC) production, including Enterobacter spp. and P. aeruginosa. Resistance patterns were particularly interesting in birds with carnivorous, scavenging, or migratory-associated behaviors. These findings highlight the role of wild birds in the ecology and dissemination of antimicrobial-resistant bacteria (ARB) and highlight the need for wildlife-based AMR monitoring programs as part of a One Health approach. Full article

Glycyrrhiza uralensis (G. uralensis), a leguminous plant, is an important medicinal and economic plant in saline–alkaline soils of arid regions in China. Its main bioactive components include liquiritin, glycyrrhizic acid, and flavonoids, which play significant roles in maintaining human health and preventing and adjuvantly treating related diseases. However, the cultivation of G. uralensis is easily restricted by adverse soil conditions in these regions, characterized by high salinity, high alkalinity, and nutrient deficiency. This study investigated the impacts of four multistrain microbial inoculants (Pa, Pb, Pc, Pd) on the growth performance and bioactive compound accumulation of G. uralensis in moderately saline–sodic soil. The aim was to screen the most beneficial inoculant from these strains, which were isolated from the rhizosphere of plants in moderately saline–alkaline soils of the Hexi Corridor and possess native advantages with excellent adaptability to arid environments. The results showed that inoculant Pc, comprising Pseudomonas silesiensis, Arthrobacter sp. GCG3, and Rhizobium sp. DG1, exhibited superior performance: it induced a 0.86-unit reduction in lateral root number relative to the control, while promoting significant increases in single-plant dry weight (101.70%), single-plant liquiritin (177.93%), single-plant glycyrrhizic acid (106.10%), and single-plant total flavonoids (107.64%). Application of the composite microbial inoculant Pc induced no significant changes in the pH and soluble salt content of G. uralensis rhizospheric soils. However, it promoted root utilization of soil organic matter and nitrate, while significantly increasing the contents of available potassium and available phosphorus in the rhizosphere. High-throughput sequencing revealed that Pc reorganized the rhizospheric microbial communities of G. uralensis, inducing pronounced shifts in the relative abundances of rhizospheric bacteria and fungi, leading to significant enrichment of target bacterial genera (Arthrobacter, Pseudomonas, Rhizobium), concomitant suppression of pathogenic fungi, and proliferation of beneficial fungi (Mortierella, Cladosporium). Correlation analyses showed that these microbial shifts were linked to improved plant nutrition and secondary metabolite biosynthesis. This study highlights Pc as a sustainable strategy to enhance G. uralensis yield and medicinal quality in saline–alkali ecosystems by mediating microbe–plant–nutrient interactions. Full article