Search Results (850)

Wastewater is a hotspot for the spread of antimicrobial resistance (AR); therefore, bacteriophages offer a promising biocontrol alternative to overcome the limitations of conventional disinfection. This study evaluated the efficacy of bacteriophages and cocktails for the biocontrol of carbapenem-resistant Klebsiella pneumoniae (CR-Kp) (CG258 and ST307) and Escherichia coli producers of extended-spectrum β-lactamases (ESBL-Ec) (ST131) in simulated wastewater. A synthetic wastewater matrix was prepared in which bacterial viability and bacteriophage stability were assessed for 72 h. CR-Kp or ESBL-Ec strain were treated with individual bacteriophages or phage-cocktails (dosed in different ways) and bacterial loads were monitored for 54 h. The Klebsiella phages FKP3 and FKP14 eliminated 99% (−2.9 Log) of CR-Kp-CG258 at 54 h, and FKP10 reduced 99% (−2.15 Log) of the CR-Kp-ST307 strains. The Klebsiella phage-cocktail in a single dose reduced to 99.99% (−4.12 Log) of the CR-Kp-CG258 at 36 h. Coliphage FEC1 reduced to 2.12 Log (99%) of ESBL-Ec-bla_CTX-M-G9, and FEC2 and FEC4 reduced approximately 1 Log (90%) of ESBL-Ec-bla_CTX-M-G9 and bla_CTX-M-G1. The coliphage cocktail increased the reduction up to 2.2 Logarithms. This study provides evidence supporting the use of bacteriophage cocktails for the control of resistant bacteria in wastewater, a sustainable intervention to mitigate the spread of AR and support water reuse safety. Full article

A novel cellulose-degrading bacterial strain, D3-1, capable of degrading cellulose under medium- to high-temperature conditions, was isolated from soil samples and identified as Staphylococcus caprae through 16SrRNA gene sequencing. The strain’s cellulase production was optimized by controlling different factors, such as pH, temperature, incubation period, substrate concentration, nitrogen and carbon sources, and response surface methods. The results indicated that the optimal conditions for maximum cellulase activity were an incubation time of 91.7 h, a temperature of 41.8 °C, and a pH of 4.9, which resulted in a maximum cellulase activity of 16.67 U/mL, representing a 165% increase compared to pre-optimization levels. The above experiment showed that, when maize straw flour was utilized as a natural carbon source, strain D3-1 exhibited relatively high cellulase production. Furthermore, gas chromatography–mass spectrometry (GC-MS) analysis of products in the degradation liquid revealed the presence of primary sugars. The results indicated that, in the denitrification of simulated sewage, supplying maize straw flour degradation liquid (MSFDL) as the carbon source resulted in a carbon/nitrogen (C/N) ratio of 6:1 after a 24 h reaction with the denitrifying strain WH-01. The total nitrogen (TN) reduction was approximately 70 mg/L, which is equivalent to the removal efficiency observed in the glucose-fed denitrification process. Meanwhile, during a 4 h denitrification reaction in urban sewage without any denitrifying bacteria, but with MSFDL supplied as the carbon source, the TN removal efficiency reached 11 mg/L, which is approximately 70% of the efficiency of the glucose-fed denitrification process. Furthermore, experimental results revealed that strain D3-1 exhibits some capacity for nitrogen removal; when the cellulose-degrading strain D3-1 is combined with the denitrifying strain WH-01, the resulting TN removal rate surpasses that of a single denitrifying bacterium. In conclusion, as a carbon source in municipal sewage treatment, the degraded maize straw flour produced by strain D3-1 holds potential as a substitute for the glucose carbon source, and strain D3-1 has a synergistic effect with the denitrifying strain WH-01 on TN elimination. Thus, this research offers new insights and directions for advancement in environmental sewage treatment. Full article

The widespread use of bacteria in bioremediation led us to consider what Compulsory Secondary Education (ESO) and Baccalaureate students know about prokaryotes and what their attitudes towards them are. This study focuses on the analysis of the arguments made by secondary school students from several Spanish schools regarding the application of bioremediation to eliminate polluting plastics from the environment. Semi-structured interviews were used to obtain information on descriptive aspects regarding the application of biotechnology to bioremediation. This instrument allows for a better understanding of what students know about biotechnology and what they value when adopting a particular attitude towards improving the environment through systematic observations and recording spontaneously occurring events. The arguments used by these students were analyzed from the perspective of the knowledge and values they consider when making their justifications. It was observed that the students viewed the use of microorganisms to treat waste positively and valued the environmental impact and scientific progress, although they had doubts about certain technical aspects. A teaching approach based on the biodegradation of plastics encourages critical thinking and can be integrated transversally into teaching, promoting debates and reflections on science and values. It is recommended that these types of activities continue to be developed to improve science education. Full article

Objectives: The global rise in multidrug resistance underscores the urgent need for the development of novel and effective antimicrobial agents. Semi-organic iodine-containing complexes, owing to their unique properties, low likelihood of resistance development, and stability under various conditions, represent a promising avenue for the design of new therapeutic strategies. This study describes the synthesis of semi-organic iodine-containing complexes and the in vitro evaluation of their impact on antibiotic susceptibility modulation in the multidrug-resistant pathogenic microorganisms S. aureus and E. coli. Methods: The physicochemical properties of the semiorganic compounds were characterized using UV-Vis spectroscopy, potentiometric, and titrimetric methods. Evaluation of antimicrobial activity was obtained according to CLSI protocols. The impact of semiorganic compounds on the in vitro susceptibility of MDR strains was evaluated by the disk diffusion method. Results: This study evaluated the effects of iodine-containing complexes KC-270 and KC-271 on the antibiotic susceptibility of Staphylococcus aureus BAA-39 and Escherichia coli BAA-196. The most pronounced effect was observed with KC-270 applied during the lag phase, which enhanced the activity of several antibiotics and, in some cases, restored susceptibility. KC-271 exhibited a weaker and more limited impact. The findings suggest that KC-270 has potential as a modulator of antibiotic susceptibility, particularly when administered at early stages of bacterial growth. Conclusions: The results support the ability of amino acid-based iodine coordination compounds to influence the antibiotic susceptibility of pathogenic bacteria, highlighting their potential as adjuvant agents to improve the effectiveness of current antimicrobial therapies. However, although changes in susceptibility were detected, neither compound fully eliminated resistance in the multidrug-resistant strains, indicating the necessity for further research into their mechanisms of action and possible synergistic interactions with antibiotics. Full article

Hydrogen sulfide (H₂S), once regarded solely as a highly toxic gas, is now recognized as a crucial signaling molecule in plants, bacteria, and mammals. In humans, H₂S signaling plays a role in numerous physiological and pathological processes, including vasodilation, neuromodulation, and cytoprotection. To exploit its biological functions and therapeutic potential, a wide range of H₂S-releasing compounds, known as H₂S donors, have been developed. These donors are designed to release H₂S under physiological conditions in a controlled manner. Among them, self-reporting H₂S donors are seen as a particularly innovative class, combining therapeutic delivery with real-time fluorescence-based detection. This dual functionality enables spatiotemporal monitoring of H₂S release in biological environments, eliminating the need for additional sensors or probes that could disrupt cellular homeostasis. This review summarizes recent advancements in self-reporting H₂S donor systems, organizing them based on their activation triggers, such as specific bioanalytes, enzymes, or external stimuli like light. The discussion covers their design strategies, performance in biological applications, and therapeutic potential. Key challenges are also highlighted, including the need for precise control of H₂S release kinetics, accurate signal quantification, and improved biocompatibility. With continued refinement, self-reporting H₂S donors offer great promise for creating multifunctional platforms that seamlessly integrate diagnostic imaging with therapeutic H₂S delivery. Full article

Microbiological contamination of healthcare workers’ gowns represents a critical risk for the transmission of healthcare-associated infections (HAIs). Despite their use as protective equipment, gowns can act as reservoirs of antibiotic-resistant bacteria, favouring the spread of pathogens between healthcare workers and patients. The presence of these resistant bacteria on healthcare workers’ gowns highlights the urgent need to address this risk as part of infection control strategies. The aim of this work was to assess the microbiological risks associated with the contamination of healthcare staff gowns with Gram-negative bacteria, including the ESKAPE group, and their relationship with antimicrobial resistance. An observational, cross-sectional, prospective study was conducted in 321 hospital workers. The imprinting technique was used to quantify the bacterial load on the gowns, followed by bacterial identification by MALDI-TOF mass spectrometry. In addition, antimicrobial resistance profiles were analysed, and tests for carbapenemases and BLEE production were performed. The ERIC-PCR technique was also used for molecular analysis of Pantoea eucrina clones. Several Gram-negative bacteria were identified, including bacteria of the ESKAPE group. The rate of microbiological contamination of the gowns was 61.05% with no association with the sex of the healthcare personnel. It was observed that critical areas of the hospital, such as intensive care units and operating theatres, showed contamination by medically important bacteria. In addition, some strains of P. eucrina showed resistance to carbapenemics and cephalosporins. ERIC-PCR analysis of P. eucrina isolates showed genetic heterogeneity, indicating absence of clonal dissemination. Healthcare personnel gowns are a significant reservoir of pathogenic bacteria, especially in critical areas of Hospital Juárez de México. It is essential to implement infection control strategies that include improving the cleaning and laundering of gowns and ideally eliminating them from clothing to reduce the risk of transmission of nosocomial infections. Full article

Honey, propolis or royal jelly are considered natural remedies with therapeutic properties since antiquity. Many papers explore the development of antimicrobial biomaterials based on individual bee products, but there is a lack of studies on their synergistic effects. Combining honey, propolis and royal jelly with silver nanoparticles in a biopolymer matrix offers a synergistic strategy to combat antibiotic-resistant bacterial infections. This approach supports progress in wound healing, soft tissue engineering and other domains where elimination of the microorganisms is needed like food packaging. In this study we have obtained antimicrobial films based on bee products and silver nanoparticles (AgNPs) incorporated in an alginate–chitosan blend. The novel biomaterials were analyzed by UV-Vis, fluorescence and FTIR spectroscopy or microscopy, SEM and thermal analysis. Antibacterial tests were conducted against both Gram-positive and Gram-negative bacteria, while the antifungal properties were tested against Candida albicans. The diameters for growth inhibition zones were up to 10 mm for bacterial strains and 8 mm for the fungal strain. Additionally, cytotoxicity assays were performed to evaluate the biocompatibility of the materials, the results indicating that the combination of honey, propolis, royal jelly and AgNPs does not produce synergistic toxicity. Full article

A series of glasses (0.48SiO₂ − [0.40-x]ZnO − 0.12CaO-xGa₂O₃, x = 0, 0.8, 0.16) was developed to formulate a series of Ga-containing glass polyalkenoate cements (GPCs). The solubility of GPCs was tested using DI water, and it was found that the sample containing the highest mol% of Ga, LGa-2, had the most Ga ion release. The GPCs were incubated in SBF, and SEM/EDS analysis revealed that the at% of P increased, while the at% of Si decreased, highlighting the CaP precipitation on the GPC surface. The at% of Ga also decreased, reinforcing the Ga release from the GPC. Cellular testing against fibroblasts and osteoblasts showed that a concentration of 25 mg/mL of the liquid extracts from the LGa-2 GPC had increased cell viability compared to other concentrations and GPCs tested. Antibacterial studies against E. coli and S. epidermidis demonstrated inhibition zones around the GPCs, highlighting their effectiveness in the elimination of bacteria on contact. Full article

Microbial infections are an escalating global health threat, driven by the alarming rise of antimicrobial resistance (AMR), which has made many conventional antibiotics increasingly ineffective and threatens to reverse decades of medical progress. The rapid emergence and spread of multidrug-resistant bacteria have severely limited treatment options, resulting in increased morbidity, mortality, and healthcare burden worldwide. In response to these challenges, phage therapy is regaining interest as a promising alternative. Bacteriophages, the most abundant biological entities, have remarkable specificity toward their bacterial hosts, enabling them to selectively eliminate pathogenic strains. Phage therapy presents several advantages over conventional antibiotics, which include minimal disruption to the microbiome and a slower rate of resistance development. Among the various sources of phages, the marine environment remains one of the least explored. Given their adaptation to saline conditions, high pressure, and variable nutrient levels, marine bacteriophages mostly exhibit enhanced environmental stability, broader host ranges, and distinct infection mechanisms, thus making them highly promising for therapeutic purposes. This review explores the growing therapeutic potential of marine bacteriophages by examining their ecological diversity, biological characteristics, infection dynamics, and practical applications in microbial disease control. It also deals with emerging strategies such as phage–antibiotic synergy, genetic engineering, and the use of phage-derived enzymes, alongside several challenges that must be addressed to enable clinical translation and regulatory approval. Advancing our understanding and application of marine phages presents a promising path in the global fight against AMR and the development of next-generation antimicrobial therapies. Full article

The high pathogenicity rate of carbapenem-resistant Pseudomonas aeruginosa (CRPA) has resulted in substantial economic losses for humans and the breeding industry. Consequently, there is an urgent need to develop new alternatives to mitigate antibiotic use. Phage therapy has demonstrated promising results in numerous studies. In this study, lytic phages targeting CRPA were isolated from feces and river water samples in Shandong, China. A total of 94 phage strains with CRPA as hosts were obtained, exhibiting lysis rates that ranged from 29% to 76% for P. aeruginosa derived from humans and different types of animals (n = 246). We further examined five representative phages, the host bacteria of which were CRPA from clinical patients and poultry, and these phages included two myoviruses and three podoviruses. Their optimal multiplicities of infection (MOIs) ranged from 10⁻³ to 10⁻⁵, with latent periods of less than 5 to 15 min and burst durations of 140 to 175 min, resulting in burst sizes of 133 to 352 PFU/cell. All five phages exhibited the ability to survive at temperatures up to 60 °C and within pH levels of 3 to 11. Whole-genome sequencing revealed that these five phages were all double-stranded DNA phages and did not possess resistance genes or virulence factors. The two myoviruses, sharing similar sequences, were classified into the genus Pakpunavirus, with a size of 92,509 bp and 92,293 bp, 149 to 152 ORFs and 20 to 22 tRNAs. In contrast, the three similar podoviruses belong to the genus Phikmvvirus and all contained a perforin–lyase system, with a size of 43.35 kb, a GC content of 62%, 49 to 50 ORFs and 16 to 20 tRNAs. A spray disinfection experiment demonstrated that the phage cocktail exhibited a high sterilization effect after spraying and showed good efficacy against cement and metal surfaces. This study provides foundational information for further research into the elimination of CRPA in the environment. Full article

Regarding the trout microbiota, most information is focused on lactic acid bacteria, which can show beneficial properties. However, in trout farming, mostly pathogenic Gram-positive species were reported, such as Staphylococcus aureus, Listeria monocytogenes, and/or Clostridium spp. In this study, free-living trout were analyzed for Gram-negative microbiota that can cause loss as disease-stimulating agents. Bacteriocin postbiotics should be one of the approaches used to eliminate these agents. In total, 21 strains of different species isolated from the intestinal tract of 50 trout in Slovakia (Salmo trutta and Salmo gairdnerii) were taxonomically allotted into 13 species and 9 genera. This method showed variability in microbiota identified using MALDI-TOF mass spectrometry with the following species: Acinetobacter calcoaceticus, Citrobacter gillenii, Citrobacter freundii, Escherichia coli, Hafnia alvei, Kluyvera cryocrescens, K. intermedia, Leclercia adecarboxylata, Raoultella ornithinolytica, Pseudomonas fragi, Ps. putida, Ps. lundensis, Ps. teatrolens, and Serratia fonticola. Most strains were susceptible to the antibiotics used, reaching inhibitory zones up to 29 mm. On the other hand, 3 out of 21 strains (14%) were susceptible to nine enterocins- postbiotics (Hafnia alvei Hal281, Pseudomonas putida Pp391, and Ps. fragi Pf 284), with inhibitory activity in the range of 100–6400 AU/mL. Full article

The Asian tiger mosquito Aedes albopictus is a highly invasive species capable of transmitting human pathogens. For population management, the sterile insect technique (SIT) is considered an effective and sustainable alternative to conventional methods, such as insecticides and reducing or eliminating breeding sites. The use of symbiotic bacteria to improve the application of SIT or design combined SIT/incompatible insect technique (IIT) approaches is currently considered. In this context, exploring the microbiota of local mosquito populations is crucial for identifying interesting components. This study employed 16S rRNA sequencing and microbiological methods to characterize the diversity of laboratory and wild Ae. albopictus in Greece. Differences were recorded between wild and lab-reared mosquitoes, with laboratory samples exhibiting higher diversity. Laboratory treatment, sex, and developmental stage also resulted in variations between communities. Populations reared in the same facility developed mostly similar bacterial profiles. Two geographically distant wild populations displayed similar bacterial profiles, characterized by seasonal changes in the relative abundance of Pantoea and Zymobacter. Wolbachia was dominant in most groups (63.7% relative abundance), especially in field-caught mosquitoes. It was identified with two strains, wAlbA (21.5%) and wAlbB (42.2%). Other frequent taxa included Elizabethkingia, Asaia, and Serratia. Blood feeding favored an increase in Serratia abundance. Various Enterobacter, Klebsiella, Aeromonas, and Acinetobacter strains were isolated from larval and adult mosquito extracts and could be further characterized as diet supplements. These findings suggest that the microbiota of local populations is highly variable due to multiple factors. However, they retain core elements shared across populations that may exhibit valuable nutritional or functional roles and could be exploited to improve SIT processes. Full article

Multidrug-resistant (MDR) bacterial infections present a major challenge in cancer therapy, particularly for immunocompromised patients undergoing chemotherapy, radiation, or surgery. These infections often arise from prolonged antibiotic use, hospital-acquired pathogens, and weakened immune defenses, leading to increased morbidity and mortality. As conventional antibiotics become less effective against MDR strains, there is an urgent need for alternative treatment options. This review highlights phage therapy as a promising approach to managing MDR bacterial infections in cancer patients. Once widely used, phage therapy has recently regained attention as a targeted antimicrobial strategy that can specifically eliminate harmful bacteria while preserving the beneficial microbiota. Phages work by directly lysing bacteria, disrupting biofilms, and synergizing with antibiotics to restore bacterial susceptibility. These mechanisms make phage therapy especially appealing for treating infections that complicate cancer treatments. However, the clinical application of phage therapy faces challenges such as variability in phage–host interactions, regulatory hurdles, and immune responses in patients. This review identifies gaps in current research regarding the use of phage therapy for MDR infections in cancer patients. By examining recent innovations, therapeutic mechanisms, and associated limitations, we provide valuable insights into the potential of phage therapy for improving infection management in oncology. Future research should focus on refining phage delivery methods, assessing long-term safety, and exploring combination therapies to maximize clinical efficacy. Overcoming these challenges could position phage therapy as a valuable complement to existing antimicrobial strategies in cancer care. Full article

This study evaluated a multi-strain starter culture’s impact on the industrial-scale fermentation of “Tonda di Cagliari” table olives, comparing processes at ambient versus controlled (23–25 °C) temperatures. Controlled fermentation accelerated acidification, yielding lower pH levels, higher lactic acid bacteria (LAB) counts, and better control over Enterobacteriaceae. Starter inoculation ensured the attainment of safe pH levels (<4.2) even at ambient temperature, while uninoculated samples did not reach safe pH levels under those conditions (>4.5 in non-inoculated samples). Regardless of processing temperature, starter-inoculated olives consistently yielded higher final concentrations of hydroxytyrosol (719.2 and 762.9 mg/kg inoculated, 480.7 and 326 mg/kg non-inoculated). Total phenolic content in olives remained higher throughout the fermentation process at the controlled temperature (3138 and 2112 mg/kg ambient temperature, 3458 and 3622 mg/kg controlled temperature). Olives maintained at controlled (higher) temperatures exhibited lower final moisture content and significantly reduced lipid content. While texture profiles were primarily affected by temperature, sensory acceptability was significantly influenced by both the starter inoculation and the fermentation temperature. These findings indicate that using microbial starters can potentially lower energy costs associated with heating processing rooms, particularly during colder seasons, while still ensuring food safety and enhancing nutraceutical value. Although the faster fermentation rate at controlled temperature did not substantially shorten overall marketing time, the starter eliminates the necessity for heating facilities to achieve a food-safe pH within a reasonable timeframe. Full article

Regulating the innate immune response against infections, particularly drug-resistant bacteria, is a key focus in anti-infection therapy. Cathelicidins, found in vertebrates, are crucial for pathogen resistance. Few studies have explored gecko cathelicidins’ anti-infection properties. Recently, five new cathelicidins (Gj-CATH1-5) were identified in Gekko japonicus. The peptide Gj-CATH5, from G. japonicus, shows promise against Pseudomonas aeruginosa through various mechanisms. This study examined Gj-CATH5’s protective effects using in vitro and in vivo models, finding that it significantly reduced bacterial load in a mouse infection model when administered before or shortly after infection. Flow cytometry and the plate counting method showed that Gj-CATH5 boosts neutrophil and macrophage activity, enhancing chemotaxis, phagocytosis, and bactericidal functions. Gj-CATH5 increases ROS production, MPO activity, and NET formation, aiding pathogen clearance. Its amphipathic α-helical structure supports broad-spectrum bactericidal activity (MBC: 4–8 μg/mL) against Gram-negative and antibiotic-resistant bacteria. Gj-CATH5 is minimally cytotoxic (<8% hemolysis at 200 μg/mL) and preserves cell viability at therapeutic levels. These results highlight Gj-CATH5’s dual role in pathogen elimination and immune modulation, offering a promising approach to combat multidrug-resistant infections while reducing inflammation. This study enhances the understanding of reptilian cathelicidins and lays the groundwork for peptide-based immune therapies against difficult bacterial infections. Full article