Search Results (3,921)

Microbial biological control agents are a sustainable alternative to synthetic pesticides, yet their widespread application is limited by a lack of environmental resilience of commercial products. To address this, we exploited honey—a stringent ecological niche—as a reservoir for stress-tolerant bacteria. In this study, the bioprospection utilizing five types of commercially available honeys yielded a collection of 53 bacteria and 10 fungi. All bacterial isolates were evaluated for antimicrobial activity against a laboratory-standard bacterium and yeast, and six economically relevant phytopathogenic microorganisms. Initial screening with standard laboratory organisms proved to be an efficient method to detect strains with antimicrobial potential, correlating significantly with further phytopathogen inhibition (Spearman’s r = 0.4512, p = 0.0005). Two promising strains, M2.7 and M3.18, were selected for quantitative dual-culture assays along with molecular identification using 16S rDNA and gyrA gene sequencing, classifying them as Bacillus velezensis. These strains exhibited high inhibitory effects against the pathogens (p > 0.001), often with equivalent efficacy to the commercial biocontrol strain, and also induced significant phytopathogen hyphal deformities, such as increased septation and swelling. These findings support honey as a viable source of robust biocontrol agents, offering a sustainable strategy to substitute or complement current agrochemicals. Full article

The paper describes a predatory Gram-negative bacterium from the genus Bdellovibrio, which was isolated from water of the Lyubozhikha River. As revealed by electron microscopy, the bacterium is an intracellular predator of Gram-negative microorganisms. Its prey range includes Pseudomonas tolaasii, the phytopathogen responsible for brown spot disease in the cultivated button mushroom (Agaricus bisporus). Based on the results of a 16S rRNA gene sequence analysis, the bacterium was identified as Bdellovibrio bacteriovorus strain LR3. We characterized the predator–prey dynamics between B. bacteriovorus LR3 and P. tolaasii, determining the optimal temperature and pH conditions for this interaction. Our results demonstrate the potential of B. bacteriovorus LR3 as a biocontrol agent against P. tolaasii in mushroom cultivation. The possibility of using B. bacteriovorus LR3 against clinical cases Salmonella and Escherichia infections is also addressed. Full article

Colostrum harbors a highly diverse microbial community, predominantly composed of genera such as Staphylococcus, Streptococcus, Lactobacillus, Bifidobacterium, and Enterococcus. The composition and diversity of this microbiota are influenced by maternal factors—including age, body mass index, lactation activity, stress levels, and gestational diabetes—as well as external factors such as mode of delivery, antibiotic exposure, diet, and geographic location. This microbial community plays a critical role in maternal and neonatal health by contributing to early gut colonization, supporting digestion, promoting immune system development, and protecting against pathogenic microorganisms through mechanisms such as antimicrobial peptide production by lactic acid bacteria. The primary aim of this study was to evaluate the impact of mode of delivery on colostrum microbiota by comparing mothers who delivered vaginally with those who underwent cesarean section. Colostrum samples from 15 mothers were subjected to DNA extraction, high-throughput sequencing, and bioinformatic analyses to characterize microbial composition and predicted functional profiles. Although substantial inter-individual variability was observed, no statistically significant differences were detected in overall microbial diversity or community structure between the two delivery groups. However, distinct bacterial taxa and functional characteristics were identified that were specific to each mode of delivery, suggesting subtle delivery-related influences on colostrum microbiota composition. Full article

Background/Objectives: Tallaga cheese is an artisanal form of traditional Egyptian soft white Damietta cheese, characterized by high moisture, elevated salinity, and a limited shelf life, which collectively increase its vulnerability to microbial contamination. Typically produced from raw or minimally heated cow or buffalo milk, Tallaga cheese represents a relevant model for studying emerging food safety challenges. Methods/Results: This study revealed marked variability among commercial samples and, unexpectedly, a general absence of typical lactic acid bacteria (LAB) such as Lactococcus spp. Instead, enterococci, microorganisms increasingly associated with antimicrobial resistance and virulence traits, emerged as the dominant LAB group, with the detection of Enterococcus faecium strains posing particular concern for dairy safety. To address these challenges, the antimicrobial potential of isolated LAB was evaluated against Latilactobacillus sakei (CECT 906). Twelve bacteriocin-producing strains were identified: ten Enterococcus faecalis, one E. faecium, and one Lactococcus lactis. Enterococci demonstrated robust tolerance to stress conditions, including high salt concentrations, emphasizing their persistence in dairy environments. Given the relevance of controlling resistant and potentially virulent strains such as E. faecium, the bioprotective capacity of two bacteriocinogenic L. lactis strains (IPLA 1064 and AHRI ST9) was assessed using a laboratory-scale cheese model. Both strains effectively inhibited E. faecium AHRI CH4, achieving reductions of 2.6 and 3.6 log units (99.9%). Conclusions: These findings underscore the relevance of bacteriocin-producing L. lactis as natural biopreservatives to mitigate emerging threats related to antimicrobial-resistant food-borne pathogens in dairy products. Full article

Staphylococcus aureus is a common opportunistic pathogen found in various environments, with the potential for rapid spread, especially in densely populated indoor settings. Integrating traditional microbiological monitoring with molecular techniques is critical for the timely detection and control of such pathogens. The aim of this study was (1) to monitor the presence and spread of S. aureus in a crowded occupational environment and (2) to optimize a PCR protocol with sequence specific primers (PCR-SSP) for precise identification and early detection of this microorganism and its antibiotic resistance genes. Sampling was conducted in two different places: a call center and a healthcare facility room. All samples were collected from indoor areas at two different time points (T0 and T1) in May 2025 (mean temperature: 22.5 °C; humidity: 59.5%). Microbiological techniques and molecular analysis using PCR-SSP were employed to confirm the presence of S. aureus and detect antibiotic resistance genes such as mecA. A total CFU (colony-forming unit) count of 587 was recorded at the dental clinic corridor, and a total CFU count of 2008 was recorded at the call center corridor. PCR-SSP successfully confirmed the identity of S. aureus with an amplicon size 267 bp and enabled the detection of antibiotic resistance markers, validating its use as a complementary method to traditional microbiological techniques. This study highlights the importance of combining environmental monitoring with molecular biology tools to enhance the early detection and accurate identification of microbial pathogens such as S. aureus and provide an insight for our future direction of producing biosensors for digital air monitoring in crowded workplaces. Full article

Schiff bases are bioactive compounds that have been synthesized by many researchers in recent years. They may also exhibit strong antimicrobial activities against various pathogenic microorganisms in both medicine and veterinary applications. The synthesis of new Schiff base-derived compounds remains of interest due to the increasing problem of antibiotic-resistance in clinical practice. Seven new Schiff base derivatives were synthesized, and their chemical structures were characterized using FT-IR, ¹H/¹³C NMR, and LCMS-MS analyses. The antimicrobial activities of thesyntesized compounds against various pathogenic bacteria, yeasts, and fungi were evaluated using the disk-diffusion method, and their MIC values were also determined. In addition, one representative microorganisms from each class were selected for molecular docking studies. IFD analyses were performed for the 4f and 4g ligands using the dihydrofolate reductase enzyme. Spectroscopic analyses confirmed the structures of the synthesized compounds, revealing the presence of characteristic imine functionalities and validating the integrity of the molecular frameworks. Antimicrobial assays demonstrated that several derivatives exhibited measurable activity, with compounds 4f and 4g showing the most potent effects, displaying MIC values of 32 µg/mL against B. cereus and E. faecalis, respectively. Molecular docking studies further indicated that both 4f and 4g bind efficiently to the DHFR active site. These findings indicate that among the synthesized Schiff base derivatives, compounds 4f and 4g exhibit particularly promising antimicrobial activity, warranting further pharmacological evaluation and medicinal chemistry optimization. Full article

Staphylococcus species are saprophytic, opportunistic, and nosocomial pathogens that frequently co-infect with other microorganisms, causing severe infections in birds. Some of the notable examples include bacterial chondronecrosis with osteomyelitis (BCO), cellulitis, dermatitis, and systemic infections. Understanding of how Staphylococcus spp. cause infections evading the host immune system is crucial for helping farmers and veterinarians develop long-term solutions for poultry production system management. The aim of this review is to broaden the understanding of Staphylococcus spp. epidemiology, virulence, genomic adaptability and coinfection patterns. The peer-reviewed articles were obtained from various databases, including Google Scholar, Web of Science, and PubMed. The review primarily focused on papers published between 1999 and 2025. The review presents an opportunity to identify research gaps and apply this knowledge to develop innovative approaches to address staphylococcal infections in broiler chickens. Additionally, BCO is often attributed to coinfection with Staphylococcus species and other pathogens. Full article

Plant disease specimens are invaluable resources for investigating the origin and spread mechanisms of plant pathogenic microorganisms. Citrus canker, caused by Xanthomonas citri pv. citri (Xcc), is one of the most devastating bacterial diseases in citrus production. Here, we report the complete genome sequence of Xcc strain GD82, isolated from Guangdong Province during the early outbreak stage in the 1980s. Comparative analysis with modern genomes revealed key differences in structural variations, functional single-nucleotide polymorphisms (SNPs), and phage-related fragments, suggesting potential associations between insertions/deletions (InDels) and pathogenicity or environmental adaptation. This study provides critical insights into the evolutionary trajectory of Xcc and the epidemiological dynamics of citrus canker in China. Full article

The presence and development of pathogens in the human body remains a serious problem. The existence of microorganisms is primarily related to their ability to adhere to various surfaces. The aim of this study was to evaluate the ability of Si(C,N) coatings on a nickel-chromium alloy surface to reduce bacterial and fungal adhesion and to provide antimicrobial activity. This publication also focused on determining which coating variant is most effective in reducing microbial adhesion. Si(C,N) coatings were sputtered onto the surface of the prosthetic alloy using the magnetron sputtering method. Observation was performed using a fluorescence microscope and a flow cytometer. The number of adhered bacterial cells decreased compared to the samples without coating (sample series A) by approximately 84% in sample series B and by 29% in sample series F. In the case of adhesion of fungal cells, their number decreased compared to the samples without coating (sample series A) by approximately 76% in sample series B and by 47% in sample series F. The applied one-way analysis of variance test indicated a statistically significant effect of the tested factor at a level below 0.001. Based on the conducted research, it was noticed that the use of Si(C,N) layers on the surface of the prosthetic alloy limits the adhesion of bacteria and fungi. Full article

Microbial contamination of food is a crucial cause of food spoilage and foodborne diseases, posing a severe threat to global public health. Although chemical preservatives are effective, their potential hazards to human health and the environment, coupled with the growing demand for “clean label” products, have driven the search for natural alternatives. Lactic acid bacteria (LAB), recognized as the Generally Recognized as Safe (GRAS) microorganisms, have emerged as the promising bio-preservatives due to their safety, effectiveness, and multifunctionality. This review systematically summarized the core antimicrobial properties of LAB, including their inhibitory spectrum against foodborne pathogens, spoilage microorganisms, viruses, parasites, and their ability to degrade toxic substances such as mycotoxins, pesticides, and heavy metals. Key inhibitory mechanisms of LAB are highlighted, encompassing the production of antimicrobial metabolites, leading to metabolism disruption and cell membrane damage, nutrition and niche competition, quorum-sensing interference, and anti-biofilm formation. Furthermore, recent advances in LAB applications in preserving various food matrices (meat, dairy products, fruits and vegetables, cereals) are integrated, including their roles in enhancing food sensory quality, extending shelf life, and retaining nutritional value. The review also discusses critical factors influencing LAB’s inhibitory activity (medium composition, culture conditions, ionic components, pathway regulator, etc.) and the challenges associated with the application of LAB. Finally, future research directions are outlined, including the novel LAB and metabolites exploration, AI-driven cultural condition optimization, genetic engineering application, nano-encapsulation and active packaging development, and building up the LAB-based cellular factories. In conclusion, LAB and their antimicrobial metabolites hold great promise as green and safe food preservatives. This review is to provide comprehensive theoretical support for the rational improvement and efficient application of LAB-based natural food preservatives, contributing to the development of a safer and more sustainable food processing and preservation systems. Full article

Composting represents a sustainable and effective strategy for converting organic waste into nutrient-rich soil amendments, providing a safer alternative to raw manure, which poses significant risks of soil, crop, and water contamination through pathogenic microorganisms. This study, conducted under semi-arid Moroccan conditions, investigated the efficiency of co-composting green garden waste with sheep manure in an open window system, with the objective of assessing pathogen inactivation and evaluating compost quality. The process, conducted over 120 days, maintained thermophilic temperatures exceeding 55 °C, effectively reducing key pathogens including Escherichia coli, total coliforms, Staphylococcus aureus, and sulfite-reducing Clostridia (SRC), while Salmonella was not detected throughout the composting period. Pathogen reductions exceeded 3.52-log despite moderate temperature fluctuations, indicating that additional sanitization mechanisms beyond heat contributed to inactivation. Compost quality, assessed using the CQI, classified Heap 2 (fallen leaves + sheep manure) as good quality (4.06) and Heap 1 (green waste + sheep manure) as moderate quality (2.47), corresponding to differences in microbial dynamics and compost stability. These findings demonstrate that open windrow co-composting is a practical, low-cost, and effective method for safe organic waste management. It supports sustainable agriculture by improving soil health, minimizing environmental and public health risks, and providing guidance for optimizing composting protocols to meet regulatory safety standards. Full article

Background: Domestic refrigeration and egg handling are key factors in ensuring household food safety. Inadequate temperature control and poor hygiene in refrigerators can promote the survival and growth of foodborne pathogens. This study aimed to (i) characterize refrigerator temperature profiles and surface microbial contamination and (ii) screen eggs and egg-storage areas for the presence of Salmonella spp. and Campylobacter spp. Methods: Fifty domestic refrigerators were monitored twice in 2024 and 2025 in Porto, Portugal. The temperatures were continuously logged on the lowest shelf, which was swabbed for microbiological analysis. Surface hygiene was evaluated using total viable counts (TVC), Enterobacteriaceae, and Escherichia coli enumerated following ISO methods. Detection of pathogens Listeria monocytogenes, Salmonella spp., and Campylobacter spp. was performed using real-time PCR. Eggs (n = 92 in 2024; n = 88 in 2025), and domestic egg storage areas (total n = 76) were screened for Salmonella and Campylobacter. Results: The mean refrigerator temperatures were 6.0 ± 0.5 °C in 2024 and 6.1 ± 0.5 °C in 2025; 44% and 50% of the units, respectively, exceeded the recommended 6 °C threshold. In 2025, 31 (62%) and 33 (66%) refrigerators showed higher TVC and Enterobacteriaceae counts compared to 2024, whereas E. coli was only detected sporadically. L. monocytogenes, Salmonella spp., or Campylobacter spp. were not recovered from the refrigerator surfaces. Likewise, Salmonella and Campylobacter were not detected in any of the eggs or egg-storage sites. Indicator microorganism’s counts were not associated with the mean temperature. Conclusions: The absence of correlation between ΔT and Δ microbial counts suggests that behaviour-driven hygiene factors, rather than the relatively small year-to-year temperature differences observed, are more influential in determining household bioburden. Maintaining refrigerator temperatures ≤ 6 °C together with simple hygiene practices remains essential for reducing household food safety risks. Full article

Background: Hermetia illucens larvae provide a sustainable bioconversion pathway that transforms agro-industrial residues into protein- and nutrient-dense biomass and frass, suitable for animal feed and soil amendment, respectively. Nevertheless, the potential spread of antibiotic resistance (AR) genes and pathogenic microorganisms poses biosafety concerns. This study examined the impact of four residue-based diet formulations; peas and chickpea (D1), peas and wheat (D2), onion and wheat (D3), and wheat with digestate (D4), on microbial safety during the bioconversion process. Methods: Enterococcus spp. (viable counts), Salmonella spp. (presence/absence), and 13 AR genes associated with resistance to tetracyclines, macrolide-lincosamide-streptogramin B, β-lactams, vancomycin, and aminoglycosides were quantified in single substrates, diets, larvae, and frass using qPCR. Results: Principal component analysis revealed diet-driven AR gene profiles. D1 lowered the levels of the greatest number of tested AR genes, particularly erm(B), tetracycline, and β-lactam genes in frass, as well as tet(O) and vanB in mature larvae. In contrast, D2 increased the AR gene levels in frass. All diets except D4 eliminated Salmonella spp. Enterococcus spp. loads varied by diet and larval stage, with D2 reducing counts in frass. Conclusions: Diet composition directly shapes microbial dynamics and AR gene dissemination, indicating that legume-based substrates may enhance biosafety in bioconversion systems. Full article

Human microbiota, a complex consortium of microorganisms co-evolved with the host, profoundly influences tissue development, immune regulation, and disease progression. Growing evidence shows that microbial metabolites and signaling molecules modulate key stem cell pathways—such as Hedgehog, Wnt/β-catenin, and Notch—thereby reprogramming stem cell fate toward tumor-suppressive or tumor-promoting outcomes. Specific taxa within oral, intestinal, and urogenital niches have been linked to cancer initiation, therapy resistance, and recurrence. In parallel, clinical studies reveal that microbiota composition affects infection dynamics: bacterial isolates from symptomatic urinary tract infections inhibit commensal growth more strongly than the reverse, with Gram-positive and Gram-negative strains displaying distinct interaction profiles. Collectively, these findings highlight microbiota’s dual role in regulating cellular plasticity and pathogenicity. Elucidating host–microbe and microbe–microbe mechanisms may guide microbiota-targeted interventions to improve cancer and infectious disease management. Full article

Smart packaging is an alternative that may not only replace plastic containers, but also enable food quality monitoring. In this study, an innovative packaging system was developed using a starch-chitosan polymer matrix, infused with rosemary essential oil (REO) as an antimicrobial agent, and betalain extract as a food quality indicator. Betalain extract, derived from beet waste, can change color with pH, making it a useful natural indicator for monitoring food freshness. This packaging system is beneficial for foods that produce metabolites related to degradation, which alter pH and allow for the visual detection of changes in product quality. The objective of this work was to develop a smart packaging system with betalains and rosemary essential oil (REO) to extend food shelf life and monitor quality during storage. REO demonstrated antimicrobial activity, but its effect did not differ significantly among the microorganisms tested. On the other hand, the betalain extract (35.75% BE v/v) completely inhibited the growth of Listeria innocua and Salmonella spp. at concentrations of 50% (v/v; 0.82 ± 0.04 mg betalain/g), showing its potential as an antimicrobial agent. The interactions between chitosan and betalains were primarily associated with electrostatic interactions between the positively charged amino groups of chitosan and the negatively charged carboxyl groups of betalains. In contrast to starch, these interactions could result from interactions between the C=O groups of betalain carboxyls and water, which, in turn, interact with the hydroxyl groups of starch through hydrogen bonding. Despite the results obtained in this study, certain limitations need to be addressed in future research, such as the variability in antimicrobial activity among different bacterial strains, which could reveal differences in the efficacy of betalains and essential oils against other pathogens. Full article