Search Results (1,013)

Antimicrobial resistance is an emerging challenge in veterinary medicine, particularly in dogs, where bacterial skin infections are highly prevalent. Honey and its bioactive extracts have emerged as potential natural alternatives to conventional antimicrobials. This study evaluated the antimicrobial activity of methanolic extracts from four honey types collected in Central Chile against multidrug-resistant (MDR) bacterial isolates from canine patients, including Enterococcus faecium, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Pasteurella multocida, and Enterobacter cloacae. Antimicrobial potency was assessed by minimum inhibitory concentration (MIC), and phenolics, flavonoids, and antioxidant capacity were quantified. All extracts inhibited bacterial growth, with E. coli, E. faecium and S. aureus being the most susceptible (MIC 3.13% w/v), while Gram-negative bacteria such a P. aeruginosa, P. multocida, and E. cloacae required higher concentrations (MIC 12.5% w/v). Secondary metabolite analysis revealed seasonal and apiary-related variations, with apiary 2 honey showing significantly higher phenolic (195.58 ± 4.28 mg GAE/100 g) and flavonoid (65.46 ± 4.35 mg QE/100 g) contents in summer. In contrast, antioxidant capacity (FRAP) did not differ significantly. These findings indicate that honey’s antimicrobial properties are closely related to its bioactive composition and influenced by season and floral origin, reinforcing its potential as a sustainable alternative to antibiotics in veterinary medicine under the One Health approach. Full article

The aim of this in vitro study was to investigate the effects of six phenolic acids applied individually and in combination at concentrations of 0–20 mM on Ambrosia artemisiifolia and soil bacteria. Chlorogenic acid (CGA), p-hydroxybenzoic acid (PHBA), and protocatechuic acid (PKA) were tested on both plants and bacteria, whereas p-coumaric (PCA), vanillic (VA), and ferulic (FA) acids were tested only on soil bacteria. The estimated EC₅₀ for radicle inhibition were 4.9 ± 0.1 mM for PHBA, 4.1 ± 0.7 mM for CGA, 6.6 ± 0.7 mM for PKA, 10.1 ± 0.9 mM for CGA + PHBA + PKA, 4.6 ± 0.4 mM for ferulic, vanillic, and p-coumaric acids (FA + VA + PCA), and 2.5 ± 0.3 mM for the combination of all six phenolic acids. Bacterial strains were less susceptible to individual phenolic acids compared to their combinations. PKA and CGA showed the strongest antibacterial activity, with PKA inhibiting 78% and killing 74% of strains at ≤10 mM, while CGA inhibited 61% and killed 57%. Conversely, PCA and VA had the weakest antibacterial effects, requiring ≥20 mM for complete inhibition. Among test genera, Stenotrophomonas, Bacillus, Peribacillus, and Pseudomonas were more susceptible than Enterobacter and Lelliottia. Subinhibitory concentrations of individual phenolic acids did not affect bacterial motility, except for PKA. The study suggests that VA, PCA and FA alone or combined and PHBA alone, appear promising for weed management. Reduced herbicide strategies may safely incorporate CGA and PKA at concentrations below 2.5 mM. Full article

Background and Objectives: ESKAPE pathogens—Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.—are major contributors to antimicrobial resistance and are associated with considerable morbidity and mortality. Their involvement in community-acquired necrotizing fasciitis (CA-NF) remains insufficiently characterized. This study aimed to determine whether ESKAPE pathogens are implicated in cases of CA-NF and to describe their prevalence, antimicrobial resistance profiles, and associated clinical outcomes. Materials and Methods: We conducted a retrospective single-center study of NF cases treated in the Plastic Surgery Department of the Emergency Hospital Bucharest (2012–2022). Sixty-five patients met clinical and surgical diagnostic criteria; cases without microbiological data were excluded. Of these, 21 patients had ESKAPE pathogens isolated within 60 min of admission and formed the study cohort. Demographic, clinical, laboratory, microbiological, susceptibility, treatment, and outcome data were analyzed descriptively, with a focus on associated mortality with exploratory comparisons to ESKAPE-negative cases. Results: ESKAPE pathogens were identified in 31.8% (21/65) of patients. S. aureus was most common (61.9%); 14.3% were MRSA (Methicillin resistant Staphylococcus aureus) and 47.6% MSSA (Methicillin sensitive Staphylococcus aureus). Overall, 52% of ESKAPE isolates were multidrug-resistant and 12% were extensively drug-resistant. These resistance patterns have implications for empiric therapy in community-acquired NF. Conclusions: ESKAPE pathogens accounted for a substantial proportion of CA-NF and frequently displayed multidrug resistance. These findings highlight the importance of considering ESKAPE pathogens in empiric management strategies for NF, particularly within regional clinical practice. Full article

Aquaponic systems are increasingly recognized as sustainable technologies for integrated fish and vegetable production. However, concerns remain regarding the potential internalization of human pathogens into vegetables grown in these systems. This study assessed the risk of pathogen internalization in lettuce leaves grown in aquaponic systems with Nile tilapia challenged with Escherichia coli or Vibrio cholerae. The system comprised nine fish tanks, eighteen hydroponic pipes, and eighty-one lettuce plants, with tanks assigned to three treatments. Samples of water, fish gut, fish blood, and lettuce leaves were collected. Microbiological analyses included selective culture, biochemical assays, and molecular identification. Although colonies consistent with E. coli and V. cholerae were recovered on selective media, molecular sequencing identified other bacterial species, including Aeromonas sp., Aeromonas caviae, Aeromonas veronii, Enterobacter hormaechei, and Citrobacter freundii. The findings indicate that conventional culture-based methods may produce false-positive results and highlight the importance of molecular confirmation. Notably, pathogenic bacteria associated with tilapia were detected and appeared capable of disseminating through the system and internalizing into lettuce tissues. This result highlights the need for biosecurity measures, contamination monitoring, and the combined use of conventional and molecular diagnostic tools to ensure accurate pathogen detection and compliance with international food safety standards. Full article

Spontaneous fermentation processes can promote uncontrolled microbial growth and increase the risk of foodborne contamination, making the characterization of artisanal beverages essential for consumer safety. This study investigated the microbial composition of quinoa-based rejuvelac, a homemade fermented drink often perceived as a functional food, with the objective of identifying potential microbiological hazards associated with its preparation. High-throughput sequencing of the 16S rRNA V3–V4 region was combined with shotgun metagenomics to profile bacterial communities and recover metagenome-assembled genomes. The analysis revealed a strong dominance of Pseudomonadales, mainly Pseudomonas, Acinetobacter, Enterobacter and Burkholderiales, while lactic acid bacteria typically responsible for stable and safe fermentations were not detected. Shotgun metagenomics recovered medium- to high-quality genomes from Burkholderiaceae and Clostridiales, supporting the overrepresentation of non-beneficial taxa and indicating deviations from expected fermentation microbiota. These results show that the spontaneous preparation of rejuvelac may favor bacterial groups associated with environmental contamination rather than fermentative pathways, underscoring the importance of hygiene practices, controlled starter cultures and monitoring strategies to mitigate microbiological risk. The study highlights the need for improved safety standards in artisanal fermented foods to prevent unintended microbial contamination and protect consumers. Full article

Background/Objectives: Antimicrobial resistance (AMR) in companion animals is an emerging public health threat due to zoonotic potential and limited therapeutic options. Dogs with otitis externa may harbor multidrug-resistant (MDR) bacteria, including Escherichia coli (E. coli), Proteus mirabilis (P. mirabilis), and Enterobacter cloacae complex (E. cloacae complex), some producing extended-spectrum beta-lactamase (ESBL) or AmpC β-lactamases. This study aimed to assess the prevalence, AMR patterns, MDR occurrence, β-lactamase production, and co-infection profiles of these pathogens in canine otitis externa. Methods: Ear canal samples were collected from 592 dogs presenting clinical signs of otitis externa, with one sample per dog included in the analysis. Samples were collected from veterinary clinics in Timiș County, Romania, from 2022 to 2025. Samples were cultured on blood agar and MacConkey agar, followed by biochemical testing and MALDI-TOF mass spectrometry for bacterial identification. Antimicrobial susceptibility testing against 15 agents across six classes was performed using the VITEK^® 2 system. MDR and β-lactamase production (ESBL, AmpC) were determined according to CLSI 2018 veterinary guidelines. Co-isolation with bacterial and fungal species were recorded. Results: E. coli, P. mirabilis, and E. cloacae complex were isolated in 9.12%, 6.25%, and 1.2% of cases, respectively. E. coli exhibited the highest resistance to aminoglycosides (tobramycin 72.2%, gentamicin 61.1%) and full susceptibility to carbapenems. P. mirabilis showed the highest resistance to ampicillin (54%) and trimethoprim + sulfamethoxazole (46%), with complete susceptibility to carbapenems and fluoroquinolones. E. cloacae complex displayed universal resistance to cephalosporins but remained susceptible to non-cephalosporin β-lactams (piperacillin–tazobactam), carbapenems and aminoglycosides. MDR prevalence was 35.2% for E. coli, 18.9% for P. mirabilis, and 14.3% for the E. cloacae complex. ESBL production was detected in 13% of E. coli and 8.1% of P. mirabilis isolates, while all E. cloacae complex isolates were AmpC-positive. Co-isolations were common, primarily involving Staphylococcus pseudintermedius (S. pseudintermedius) and Malassezia pachydermatis (M. pachydermatis). Conclusions: MDR and β-lactamase-producing bacteria were identified in dogs with otitis externa, emphasizing the importance of routine antimicrobial susceptibility testing, targeted therapy based on local resistance profiles, and continuous AMR surveillance to prevent treatment failure and mitigate zoonotic risk. Full article

Humulus lupulus L. (hops), belonging to the Cannabaceae family, is grown mainly for brewing, with 98% of global production directed to this sector. Moreover, large volumes of female cone residues are generated as by-products, representing a valuable source of bioactive compounds that can be valorized under green chemistry principles. This study aimed to extract bioactive compounds from hop cone residues sourced from craft breweries using ultrasound-assisted (EH-UA) and microwave-assisted (EH-MA) extraction methods. Hydroalcoholic extracts (70%) were analyzed for chemical composition, antioxidant, antimicrobial, antiproliferative, nitric oxide (NO)-production inhibition, and photoprotective activities. GC-MS identified 32 compounds in EH-MA and 30 in EH-UA, including terpenes, sesquiterpenes, oxygenated sesquiterpenes, and fatty acids. Both extracts demonstrated strong antioxidant activity in cell-based (TBARS, OxHLIA) and chemical (DPPH, ABTS, FRAP) assays, particularly EH-MA. Significant antibacterial activity was observed, especially against Enterobacter cloacae, Pseudomonas aeruginosa, and Staphylococcus aureus (MIC 1–10 mg/mL), as well as antifungal activity against Aspergillus brasiliensis (MIC 2–2.5 mg/mL). Selective antiproliferative activity was observed against tumor cell lines Caco-2 and MCF-7 (GI₅₀ 25 μg/mL), without cytotoxicity toward nontumor cell lines Vero and PLP2 (GI₅₀ > 400 μg/mL). All extracts inhibited the production of the inflammation mediator NO, with EH-MA showing the most potent effect (IC₅₀ of 35 μg/mL), followed by EH-UA (IC₅₀ of 55 μg/mL). Photoprotective potential was also demonstrated, with SPF values of 19 (EH-MA) and 18 (EH-UA). In conclusion, hop cone residues can yield multifunctional extracts with antioxidant, antimicrobial, antiproliferative, anti-inflammatory, and photoprotective activities, which support their sustainable upcycling for pharmacological, nutraceutical, and cosmetic applications. Full article

The growing demand for efficient and cost-effective industrial proteases has intensified bioprospecting efforts in diverse ecosystems as a strategy to identify microorganisms with enhanced enzymatic performance. This study aimed to isolate, identify, and evaluate aerobic protease-producing bacteria from animal-protein matrices and water sources collected across the three continental regions of Ecuador, and to assess their suitability for industrial enzyme production A total of 34 bacterial strains were isolated and taxonomically assigned to the orders Enterobacterales, Pseudomonadales, and Bacillales. Proteolytic activity was evaluated using azocasein and casein assays after cultivation in an optimized medium containing 1% soybean paste as an inducer at 37 °C and 120 rpm for 72 h. Enterobacter cloacae (BC, pork), Bacillus paramycoides (P2, snook), and Pseudomonas aeruginosa (CH1, chontacuro) were identified as the most active protease producers from the Andean (Sierra), coastal (Costa), and Amazon regions, respectively. Production kinetics revealed marked strain-dependent differences. BC and P2 reached maximum proteolytic activity on day 4 followed by a decline, whereas CH1 peaked on day 2 and maintained stable activity over time, indicating superior enzymatic stability. Partial purification by gel-filtration chromatography (Sephadex G-100) yielded fractions with enhanced proteolytic activity, while SDS-PAGE analysis confirmed successful enrichment of protease-containing fractions. Overall, the results demonstrate that ecological origin strongly influences protease production and stability, and identify Pseudomonas aeruginosa CH1 as a particularly promising candidate for industrial applications requiring robust and sustained proteolytic activity. Full article

Fish host complex intestinal bacterial communities that contribute to a wide range of functions, from nutrient assimilation to modulation of the immune system. Understanding how environmental and host-related factors shape the fish gut microbiota is essential for advancing sustainable aquaculture practices. This study compared the intestinal microbiota of gilthead sea bream (Sparus aurata) between wild and aquaculture populations in western Greece using 16S rRNA gene amplicon sequencing targeting the V3–V4 region, combined with culture-based methods. The analysis was based on a 97% similarity threshold and included 141 gastrointestinal samples of fish collected at two aquaculture facilities and two wild fisheries, representing two different growth phases (150 g and 300 g body weight). High-throughput sequencing data revealed a clear separation of gut microbial communities according to origin (wild vs. aquaculture), geographic location, and body growth phase, with most wild fish groups exhibiting higher microbial diversity than their farmed counterparts, except for group MES_150 which showed similar or lower values. The gut microbiota was dominated by Pseudomonadota (53%), Bacillota (29%), Actinomycetota (7%), Deinococcota (5%), and Bacteroidota (4%). A shared core microbiome, comprising Psychrobacter, Staphylococcus, Geobacillus, Aeromonas, Enterobacter, Pantoea, Bacillus, and Acinetobacter, was detected across all populations. Wild fish were enriched in Psychrobacter, Aeromonas, and Photobacterium, while aquaculture fish displayed higher abundances of Vibrio, Allomeiothermus, and Staphylococcus. Network analysis revealed mostly mutually exclusive interactions in both groups but distinct patterns of co-occurrence, driven mainly by Paenibacillus, Enterobacter, and Staphylococcus in wild samples, and by Vibrio, Aeromonas, and Pseudomonas in farmed fish. Culture-based assays demonstrated greater diversity in wild fish, dominated by Pseudomonas, Staphylococcus, and Vibrio strains, in contrast to the frequent occurrence of Staphylococcus and Psychrobacter in aquaculture samples. The findings suggest that aquaculture practices significantly alter gut microbial community structure and reduce diversity, with potential implications for fish health and disease resistance. The identified core and differentially abundant taxa provide candidates for probiotic development to improve aquaculture sustainability. Full article

Background: Curcumin (Cur) has therapeutic potential for inflammatory bowel disease (IBD) but is limited by its poor bioavailability. Methods: This study demonstrated that Cur-loaded core–shell structured microgel nanoparticles (LF/CP-Cur MN), fabricated through electrostatic complexation between lactoferrin and citrus pectin, followed by Ca²⁺ consolidation, overcome this limitation. Results: These nanoparticles effectively reduced the bitterness and astringency of curcumin while prolonging its release time. In an IBD mouse model, LF/CP-Cur MN treatment mitigated symptoms and inflammation of IBD, and restored intestinal barrier integrity. Crucially, compared with free Cur, the LF/CP-Cur MN enhanced colon-targeted accumulation of Cur and favorably modulated the gut microbiota by increasing beneficial genera like Lactobacillus and Dubosiella, while suppressing harmful genera like Enterobacter, thereby promoting levels of acetate, propionate, and butyrate. Conclusions: These findings highlight the potential of the LF/CP-Cur MN to improve Cur bioaccessibility and exert dual functional roles in modulating gut microbiota and alleviating inflammation, thus offering a promising dietary strategy for the management of IBD. Full article

Background/Objectives: In the broad and current context of antimicrobial resistance, antibiotic management and therapeutic surveillance are essential in hospitals. The present study (five-year retrospective, 2020–2024) aimed to analyze antibiotic consumption in relation to pathogens identified in a multidisciplinary hospital. Results: In terms of antibiotic consumption (overall 2020–2024), although initially Watch antibiotics were predominantly used, a decrease was observed in favor of Access class antibiotics (sharply increase from 2022 to 2023 and maximum in 2024). For Reserve antibiotics, only slight annual fluctuations were observed, but there was an important reduction in colistin consumption. The most used were cephalosporins (cefazolin, cefuroxime and ceftriaxone), carbapenems (meropenem and ertapenem), vancomycin and linezolid. Regarding pathogens, the most notable were: Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Enterococcus spp., Pseudomonas aeruginosa. Among the ESKAPE bacteria, Acinetobacter baumannii was the least frequent in our samples. ESKAPE bacteria predominantly colonized specimens from the respiratory tract, digestive tract, skin and soft tissue. Resistant strains were observed, mainly Methicillin-resistant Staphylococcus aureus (MRSA) and Extended-Spectrum Beta-Lactamase (ESBL) Klebsiella spp., but no alarming increases in number were recorded in the analyzed period. Methods: The analysis was carried out using tools recommended by the World Health Organisation (Access Watch Reserve antibiotics classification (AWaRe); Bacterial Priority Pathogen List (BBPL); Defined Daily Dose (DDD)), Average Annual Percent Change (AAPC) calculation and ESKAPE classification (bacteria group: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.). Conclusions: Relatively stable trends in bacterial isolates and resistant strains over five years (2020–2024) are consistent with effective antimicrobial stewardship practices. Full article

Although many studies have focused on the initial adhesion of bacteria, there have been few that looked at responses to changing environmental conditions. To more closely examine the viscoelastic nature of initial adhesion, surface-associated bacteria were quantified and monitored for their Brownian motion vibrations. This study used a flow chamber to observe the surface association of Enterobacter cloacae BS 1037, Staphylococcus aureus ATCC 12600, Klebsiella pneumoniae–1, Acinetobacter baumannii–1, Pseudomonas aeruginosa PA O1, and Enterococcus faecalis 1396 to glass under dynamic shear rates of 7–15–30 s⁻¹, 15–30–60 s⁻¹, and 30–15–7 s⁻¹. Comparing increasing and decreasing shear rates, information about retention and recovery became apparent. Coccoid bacteria primarily reacted to directional changes in shear rates with changes in either surface-associated bacterial densities or surface-associated strength independently. A. baumannii and E. faecalis did not change their associated strength, whereas S. aureus did not change its associated density. Bacillus bacteria demonstrated differences in both associations with directional changes in shear rates. We demonstrate that retention and recovery are different methods of adaptation to environmental conditions utilised by different bacterial species. These adaptations may form the basis of upregulation and downregulation responses used for survival. Full article

This study evaluated the potential of electronic nose (E-nose) technology to discriminate Spanish-style green table olives spoiled by different bacterial strains. Microbial growth, physicochemical properties, sensory attributes, and volatile organic compounds (VOCs) profiles were analyzed to assess spoilage patterns. The results indicated strain-dependent microbial survival during incubation, with Bacillus cereus and Enterobacter cloacae showing the highest tolerance. Inoculated olives exhibited significant changes in color, texture, pH, phenolic content, and antioxidant activity compared to the Control. Sensory evaluation revealed a reduction in positive attributes and the emergence of defects such as cooked, rancid, and woody aromas, particularly in olives inoculated with B. cereus and Escherichia coli. VOC analysis confirmed these alterations, showing strain-specific increases in aldehydes, phenols, and esters, along with reductions in alcohols and acids. Principal component analysis (PCA) of E-nose data successfully distinguished two groups—spoiled and non-spoiled samples—explaining 84.8% of variance, while Partial Least Squares Discriminant Analysis (PLS-DA) achieved a classification accuracy of 90.4%. These findings highlight the E-nose as a rapid, non-destructive, and reliable tool for detecting bacterial spoilage in table olives, with potential applications in quality control and early spoilage detection. Full article

Carbapenem-resistant Enterobacter cloacae Complex (CRECC) has emerged as an important multidrug-resistant pathogen in healthcare settings, although it has historically received less attention than carbapenem-resistant Klebsiella pneumoniae and other major carbapenem-resistant Enterobacterales (CRE). Recent epidemiological reports from several regions indicate increasing detection rates of CRECC in tertiary hospitals, where it is associated with bloodstream infections, pneumonia, urinary tract infections, and prolonged hospitalization. The dissemination of carbapenemase genes, particularly bla_NDM, bla_KPC, and bla_OXA-48-like, carried predominantly on conjugative plasmids (e.g., IncFII, IncX3, IncL), represents the primary resistance mechanism, often accompanied by porin loss and efflux pump overexpression. High-risk clones such as ST171 and ST78 contribute to nosocomial persistence and outbreak potential. Beyond clinical settings, CRECC and related resistance determinants have been reported in companion animals, livestock, food products, wastewater systems, and natural aquatic environments. Although most available studies examine these sectors separately, the recurring detection of genetically related resistance genes and plasmid types suggests potential epidemiological links that warrant integrated surveillance. Environmental reservoirs, particularly hospital effluents and wastewater treatment systems, may facilitate the maintenance and dissemination of resistance genes. This review synthesizes current evidence on the epidemiology, resistance mechanisms, and evolutionary dynamics of CRECC in human, animal, and environmental contexts under a One Health framework. A better understanding of its ecological distribution and genetic plasticity is essential to inform coordinated surveillance strategies and mitigate the public health risks associated with the continued spread of carbapenem resistance. Full article

Constructed wetlands (CW) are a low-cost alternative for wastewater treatment, where microbial communities play a key role in the biotransformation of pollutants, including sulfur compounds. This study reports the identification of cultivable bacteria involved in the sulfur cycle (SC) in a subsurface-flow CW located in Tetipac, Mexico. Water, sediment, and rhizosphere samples were collected during four sampling events and plated on a mineral medium with thiosulfate. Colony-forming units were quantified, and 15 isolates were genetically identified by partial 16S rRNA gene sequencing. Bacterial abundance was higher in the rhizosphere, and the cultivable fraction was dominated by Pseudomonadota, particularly Gammaproteobacteria, accompanied by Bacteroidota and several previously uncultured lineages; genera such as Achromobacter, Chitinophaga, Enterobacter, Pseudomonas, Raoultella and Stenotrophomonas were recovered. Biochemical assays revealed heterogeneous metabolic profiles, with several isolates showing activities comparable to canonical sulfur-oxidizing bacteria (SOB). Most isolates oxidized thiosulfate and a substantial proportion oxidized elemental sulfur, with higher metabolic performance in rhizosphere isolates and a positive association with BOD₅ removal. Overall, these results indicate that the Tetipac wetland harbors a cultivable community of largely non-canonical SOB whose mixotrophic versatility and spatial differentiation suggest a key contribution to the SC and organic matter degradation in CW. Full article