International Microbiology最新文献

{"title":"Antibacterial and antibiofilm properties of 1,3,4-oxadiazoles against multidrug-resistant Pseudomonas aeruginosa isolated from burn infections - an in vitro study.","authors":"Mohsen Nazari, Mohammad Mahdi Majzoobi, Mohammad Yousef Alikhani, Abbas Ali Imani Fooladi","doi":"10.1007/s10123-026-00890-5","DOIUrl":"https://doi.org/10.1007/s10123-026-00890-5","url":null,"abstract":"<p><strong>Background: </strong>Pseudomonas aeruginosa is a major causative agent of burn wound infections, frequently characterised by multidrug resistance (MDR) and robust biofilm formation, which limit the efficacy of conventional antibiotics. 1,3,4-Oxadiazole derivatives have emerged as potential antimicrobial and antibiofilm agents; however, comprehensive evaluations against clinical MDR isolates from burn patients remain limited. The objective of this study was to investigate the in vitro antibacterial and antibiofilm activities of a synthesised 1,3,4-oxadiazole compound against clinical MDR P. aeruginosa isolates from burn wounds. In addition, the study sought to assess its synergistic potential with gentamicin and imipenem, and to examine its effects on biofilm-associated gene expression.</p><p><strong>Materials and methods: </strong>A total of 75 non-duplicate clinical P. aeruginosa isolates were collected from patients admitted to educational hospitals in Hamedan, Iran, including 49 burn-wound isolates and 26 respiratory isolates. From the initial burn-wound collection, nine isolates were selected for detailed antimicrobial and antibiofilm analyses based on their clinical relevance and biofilm phenotype; these comprised seven MDR and two non-MDR isolates, all demonstrating strong or intermediate biofilm formation. Antimicrobial susceptibility and biofilm formation were assessed using the disk diffusion and microtiter crystal violet assays. MIC, MBC, MBIC, and MBEC values were determined for 1,3,4-oxadiazole, gentamicin, and imipenem. Checkerboard assays were performed to evaluate the combined effects of 1,3,4-oxadiazole with gentamicin or imipenem against planktonic and biofilm-associated cells. The effects of sub-inhibitory concentrations of 1,3,4-oxadiazole on lasR and algD expression were evaluated using real-time PCR.</p><p><strong>Results: </strong>Among the 75 clinical isolates, 57 (76%) were classified as MDR and 74 (98.7%) produced biofilms. From the 49 burn-wound-derived isolates, nine were selected for downstream analysis, including seven MDR and two non-MDR isolates, all exhibiting strong or intermediate biofilm formation. The geometric mean MIC, MBC, MBIC, and MBEC values of 1,3,4-oxadiazole against these selected burn isolates were 20.54, 41.21, 52.56, and 105.11 µg/mL, respectively. In the checkerboard assays, 1,3,4-oxadiazole showed enhanced activity in combination with gentamicin and imipenem. For planktonic cells, the gentamicin-oxadiazole combination yielded geometric mean FIC and FBC indices of 0.54 and 0.50, respectively, whereas the imipenem-oxadiazole combination produced corresponding values of 0.72 and 0.62. Synergistic interactions were observed in 3 of the 9 selected isolates (33.3%). Against biofilm-associated cells, the gentamicin-oxadiazole combination resulted in geometric mean FBIC and FBEC indices of 0.55 and 0.59, while the imipenem-oxadiazole combination showed values of 0.62 and 0.61, indicating a simi","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148880022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antibiofilm potential of biogenic magnesium oxide nanoparticles against multidrug resistant gram-negative bacteria.","authors":"Rafia Anwer, Safdar Ali, Muhammad Shahid Mehmood, Areej Safdar, Hikmat Ullah, Mohammad Azhar Kamal, Saima Inam, Mohammad Jalal Nazari","doi":"10.1007/s10123-026-00881-6","DOIUrl":"https://doi.org/10.1007/s10123-026-00881-6","url":null,"abstract":"<p><p>Antibiotic resistance among Gram-negative bacteria, particularly those capable of forming biofilms, has become a serious clinical challenge with limited treatment options. In this study, magnesium oxide nanoparticles (MgO NPs) were synthesized using a green, cost-effective approach based on aqueous leaf extract of Cymbopogon citratus (lemongrass) and evaluated for their antibacterial and antibiofilm potential against multidrug resistant (MDR) clinical isolates of Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli. Minimum inhibitory concentration (MIC) values determined by broth microdilution ranged from 250 to 500 µg/ml, and minimum bactericidal concentration (MBC) values ranged from 1000 to 2000 µg/ml. Antibacterial activity assessed by the well diffusion method was dose-dependent, with inhibition zones ranging from 18 to 28 mm. The effect of MgO NPs on biofilm formation and eradication of pre-formed biofilms was evaluated using microtiter plate assay with crystal violet staining. Percentage inhibition of biofilm formation ranged from 27 to 97.1%, while eradication of established biofilms ranged from 51.9 to 96.4%. Exposure to sub-inhibitory concentrations of MgO NPs led to a 2 to 3-fold increase in reactive oxygen species (ROS) production in treated cells compared to controls. MgO NPs also significantly reduced the protein, carbohydrate, and DNA content of the biofilm matrix. Swimming, swarming, and twitching motility were markedly reduced in treated isolates. Congo red agar assay confirmed that slime production was inhibited following NP treatment. These findings suggest that biogenically synthesized MgO NPs hold considerable promise as antibacterial and antibiofilm agents against MDR Gram-negative pathogens.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148793127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical profile and bacterial potential of Psidium cattleyanum leaf extract against multidrug-resistant Staphylococcus aureus.","authors":"Beatriz Meyruze Barros da Fonsêca, Valquíria Bruna Guimarães Silva, Bruna de Sousa Gomes, Paloma Maria da Silva, Beatriz Estandislau Lins de Carvalho, Paulo Henrique Eloi Fernandes, Magda Rhayanny Assunção Ferreira, Luiz Alberto Lira Soares, Alisson Macário de Oliveira, Maria Tereza Dos Santos Correia, Wêndeo Kennedy Costa, Márcia Vanusa da Silva","doi":"10.1007/s10123-026-00880-7","DOIUrl":"https://doi.org/10.1007/s10123-026-00880-7","url":null,"abstract":"<p><p>The increasing prevalence of multidrug-resistant (MDR) Staphylococcus aureus represents a major challenge for global public health and highlights the urgent need for new antimicrobial strategies. In this context, plant-derived compounds have emerged as promising sources of bioactive molecules with antimicrobial and antivirulence potential. The present study investigated the phytochemical profile and antimicrobial properties of a hydroalcoholic leaf extract of Psidium cattleyanum against reference and multidrug-resistant S. aureus strains. Phytochemical analyses revealed the presence of bioactive metabolites, particularly flavonoids and ellagic acid derivatives. Antimicrobial activity was evaluated through minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays, as well as growth curve analysis. The extract inhibited all tested strains, with MIC values ranging from 128 to 256 µg/mL and MBC values between 256 and 512 µg/mL. Additionally, the extract significantly reduced important virulence factors of S. aureus, including hemolytic activity and staphyloxanthin production. Synergistic interactions were also observed when the extract was combined with ciprofloxacin or gentamicin, markedly enhancing the antibacterial activity of both antibiotics. These findings indicate that P. cattleyanum contains bioactive compounds capable of inhibiting bacterial growth and attenuating virulence mechanisms in S. aureus, highlighting its potential as a source of natural agents for the development of alternative or adjunctive antimicrobial therapies against resistant pathogens.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148793088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quinolone resistance of Pseudomonas aeruginosa isolated from hospital infections and MexAB-OprM efflux pumps.","authors":"Javad Rasouli, Hamid-Reza Goli, Shirin Sam-Daliri, Mohammad Ahanjan, Hamed Afkhami","doi":"10.1007/s10123-026-00877-2","DOIUrl":"https://doi.org/10.1007/s10123-026-00877-2","url":null,"abstract":"<p><strong>Introduction: </strong>Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen frequently associated with multidrug-resistant nosocomial infections. The MexAB-OprM efflux system, a member of the Resistance-Nodulation-Division (RND) family, contributes to intrinsic and acquired resistance by extruding structurally diverse antimicrobial agents, including quinolones, from the bacterial cell.</p><p><strong>Aim: </strong>This study aimed to evaluate the association between quinolone resistance phenotypes and the presence of the mexAB-oprM determinant in clinical P. aeruginosa isolates, and to assess the functional contribution of efflux activity using the inhibitor PAβN.</p><p><strong>Methodology: </strong>This cross-sectional descriptive study was performed on 55 samples of P. aeruginosa isolated from patients visiting the Martyr Zare hospital in the city of Sari, Iran. The genus and types of isolated strains were first characterized by biochemical tests. Antibiotic-resistance patterns of the strains were evaluated based on the disk diffusion method toward 13 common antibiotics and minimum inhibitory concentration (MIC) in the presence of the PAβN inhibitor of levofloxacin antibiotic-2 and ciprofloxacin. Finally, the presence of the mexAB-oprM operon was surveyed using the polymerase chain reaction (PCR) method.</p><p><strong>Results: </strong>In this experiment, the highest bacterial resistance was observed toward nalidixic acid (100%), ofloxacin (80.2%), and levofloxacin (74.82%) antibiotics. The lowest resistance of antibiotics was seen toward piperacillin (39.4%), meropenem (44.3%), and imipenem (48.9%). In this study, a total of 55 clinical P. aeruginosa isolates were analyzed, of which 39 (70.90%) carried the mexB determinant.</p><p><strong>Conclusion: </strong>The findings demonstrate a strong association between the presence of the mexAB-oprM determinant and elevated quinolone resistance in clinical P. aeruginosa isolates. The significant reduction in MIC values following PAβN exposure supports the contribution of RND-type efflux mechanisms to resistance. However, given the intrinsic nature of MexAB-OprM and the broad inhibitory spectrum of PAβN, these results should be interpreted as correlative rather than causative. These data underscore efflux activity as a key resistance factor and highlight the need for expression-based profiling in future mechanistic studies.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148793081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation, genomic characterization, and biocontrol potential of a bacteriophage cocktail against Staphylococcus aureus in milk.","authors":"Naim Deniz Ayaz, Gizem Cufaoglu, Gorkem Cengiz, Bahar Onaran Acar, Nurhan Ertas Onmaz, Gultekin Unal, Muammer Goncuoglu, Irfan Erol","doi":"10.1007/s10123-026-00862-9","DOIUrl":"https://doi.org/10.1007/s10123-026-00862-9","url":null,"abstract":"<p><p>The objectives of this study were to isolate, characterize, and evaluate the biocontrol potential of Staphylococcus aureus-targeting bacteriophages in milk. From wastewater and raw milk samples, a total of 19 lytic phages were isolated. Among them SAKAY1298 and SAKAY1306 phages were selected for detailed phenotypic and genomic analysis based on their lytic profiles, host range and growth kinetics. Both phages exhibited icosahedral capsids with short, non-contractile tails under transmission electron microscopy. The phages exhibited moderate acid tolerance by remaining stable at pH 4 and maintained thermal stability at temperatures up to 50 °C. They also maintained high titers over one year at + 4 °C and -80 °C in tryptic soy broth and Tris-buffered saline (1 ×). Genome analyses revealed that both phages possess complete genomes (~ 17.5 kb), encoding 18 phage-related genes and lacking virulence and resistance determinants. Comparative and phylogenetic analyses confirmed assignment to the genus Rosenblumvirus, with 99% query coverage and ~ 92% whole-genome nucleotide identity to Staphylococcus phage vB_SauR_SW21 (GenBank accession OR683639.1). Significant reductions in S. aureus counts were achieved following phage cocktail treatment, reaching up to 4.31 log CFU/mL in vitro at 37 °C and 1.44 log CFU/mL in UHT milk at 4 °C (p < 0.001). Additionally, the phage cocktail fully inhibited the production of staphylococcal enterotoxin A in the in vitro assay. Altogether, the data supports the application of SA1298KAY and SA1306KAY phages have strong potential as effective biocontrol agents for reducing S. aureus in dairy applications.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148759394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hyperin application modulates leaf bacterial communities and reduces tobacco-specific nitrosamines in air-cured Burley tobacco.","authors":"Ji Feng, Sicheng Liu, Baoming Qiao, Ruiwei Yang, Juan Liu, Xiongfei Rao, Mei Yang, Jinpeng Yang","doi":"10.1007/s10123-026-00866-5","DOIUrl":"10.1007/s10123-026-00866-5","url":null,"abstract":"<p><p>To study the effect of hyperin on the bacterial community diversity and richness on the leaves surface of Burley tobacco, a variety of Burley tobacco 'Eyan 1' was used as the research material. The day before the harvest, all leaves in the treatment group were sprayed with hyperin, while all leaves in the control group were treated with pure water. Samples were collected on the day of harvesting, as well as two weeks and four weeks after air-curing. The results showed that the application of hyperin could potentially affect the bacterial community diversity and richness on the Burley tobacco leaves. Bacterial community structure, co-occurrence patterns, and predicted metabolic pathways were analyzed. Hyperin treatment was associated with increased relative abundance of several genera, including Agrobacterium, Stenotrophomonas, and Bacillus, which have been previously linked to nitrogen transformation or TSNA reduction. These microorganisms may contribute to TSNA reduction during air-curing, thereby reducing TSNA accumulation in the upper leaves of Burley tobacco. The results of this study can furnish evidence for investigating the impact of hyperin on the microbial community and deepen our understanding of the regulatory mechanisms of hyperin in Burley tobacco.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148723763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ocotea odorifera extract: antimicrobial and antibiofilm activities, phytochemical aspects, cytotoxicity and anti-inflammatory potential of an endangered plant species.","authors":"Marcus Vinícius Dias-Souza, Marcos Junior de Oliveira Moura-Borges, Josimar da Silva Oliveira, Ana Júlia Marques de Abreu, Markus Kohlhoff, Isabela Penna Ceravolo","doi":"10.1007/s10123-026-00878-1","DOIUrl":"10.1007/s10123-026-00878-1","url":null,"abstract":"<p><p>Exploring natural products in drug discovery can provide new options for effective treatments for infectious diseases. Biofilms are frequently not considered in most studies of antimicrobial activity, despite their relevance in microbial pathogenicity and resistance to antimicrobials. Here we investigated the antimicrobial and antibiofilm potentials of Ocotea odorifera, a Brazilian endangered species, against clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. We assessed the activity of the extract using minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and minimal biofilm eradication concentration (MBEC) assays, and a skin infection model. We evaluated the cytotoxicity of the extract in BGM cells and assessed its anti-inflammatory potential. Phytochemical profiling was conducted using classical methods and UHPLC-HRMS/MS. The extract was active against the planktonic cells of all species (MIC = 8 µg/mL, variable MBC values), and eradicated biofilms of S. aureus (MBEC = 256 µg/mL). Phytochemical analysis indicated that erucamide was the most abundant compound in the sample, which is being described for this species for the first time along with other phytomolecules. The extract did not show cytotoxicity and presented anti-inflammatory activity comparable to meloxicam. Our data provides evidence on the antimicrobial activity of O. odorifera, especially its antibiofilm potential, and highlights the need of preservation of endangered species as a valuable source of bioactive metabolites of clinical interest. More studies are necessary to investigate these pharmacological properties in vivo.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148726028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of hypertension-associated bacterial key genes as potential targets and therapeutic agents through integrated bioinformatics approach.","authors":"Most Shermin Akter Sumi, Md Tahalil Islam Rahat, Most Nusrat Jahan Resma, Md Feroj Ahmed, Md Nurul Haque Mollah, Md Kaderi Kibria","doi":"10.1007/s10123-026-00879-0","DOIUrl":"https://doi.org/10.1007/s10123-026-00879-0","url":null,"abstract":"<p><p>Hypertension (HTN) is a major global health burden and a leading risk factor for cardiovascular morbidity and mortality. Although numerous studies have explored host genetic factors and molecular mechanisms underlying HTN, increasing evidence indicates that gut microbiota dysbiosis also contributes to disease development. However, the specific microbial genes involved in HTN pathogenesis and their potential therapeutic targeting remain largely unexplored. This study aimed to identify HTN-associated differentially abundant bacterial genes (DAGs), prioritize bacterial key genes (bKGs) from among them, and repurpose potential therapeutic agents targeting these bKGs using an integrated bioinformatics framework. A total of 167 stool (fecal) microbiome samples, comprising 72 samples from HTN patients and 95 samples from HCs, were analyzed using publicly available 16 S rRNA sequencing data. After quality processing and clustering at 97% similarity, 95,361 representative operational taxonomic units were obtained. Microbial diversity analysis revealed significant alterations in community composition between HTN and HC groups. Differential abundance analysis identified 24 significantly altered bacterial genera associated with HTN. Functional prediction analysis further revealed 28 differentially abundant metabolic pathways and 631 differentially abundant bacterial genes (DAGs) potentially involved in HTN pathogenesis. From these DAGs, protein-protein interaction network analysis prioritized ten hub genes as bKGs (alsB, ampC, gsiB, araC, coaA, dnaB, fruA, ssuA, minE and tsx) representing potential microbial therapeutic targets. Structure-based molecular docking identified five approved drugs, namely Azilsartan, Eplerenone, Candesartan, Conivaptan, and Telmisartan, as top-ranked compounds exhibiting strong binding affinities toward the proposed targets. ADMET evaluation suggested favorable pharmacokinetic and safety profiles for Azilsartan, Eplerenone, and Candesartan. Furthermore, molecular dynamics simulation analyses confirmed that Eplerenone and Candesartan exhibited greater structural stability and sustained binding interactions, suggesting their potential as promising therapeutic candidates for HTN management. Therefore, this study identifies microbial gene signatures potentially involved in HTN and proposes a microbiome-guided drug repurposing strategy targeting bacterial functional pathways. These findings provide novel insights into microbiota-host interactions in HTN and highlight promising therapeutic candidates that warrant further experimental and clinical validation.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148697523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antimicrobial, antibiofilm, and molecular docking evaluation of silver nanoparticles biosynthesized from Ocimum campechianum against Staphylococcus spp.","authors":"Natilene Silva Dos Santos, Nayara Andreo, Arun Kumar Jaiswal, Milena Lima Guimarães, Tania Maria Sarmento da Silva, Helinando Pequeno de Oliveira, Mateus Matiuzzi da Costa","doi":"10.1007/s10123-026-00882-5","DOIUrl":"https://doi.org/10.1007/s10123-026-00882-5","url":null,"abstract":"<p><p>Antimicrobial resistance and the overuse of antimicrobials have driven the search for innovative therapies, particularly those based on natural compounds and medicinal plant derivatives, aiming to develop new drugs. This study aimed to investigate the antimicrobial and antibiofilm activities of crude ethanolic extract of O. campechianum (CEE-OC), and commercial (AgNPs-C), non-commercial (AgNPs-NC), and Ocimum campechianum-biosynthesized (AgNPs-OC) silver nanoparticles, against 21 Staphylococcus spp. isolates. Antimicrobial activity of rosmarinic acid (RA) against six isolates was also determined. The minimum inhibitory concentration (MIC) of CEE-OC ranged from 6,250 to 781.25 µg/mL, showing the highest antimicrobial activity among the substances evaluated. AgNPs-OC exhibited MIC values approximately fourfold lower than those of CEE-OC. In contrast, AgNPs-C and AgNPs-NC showed no antimicrobial activity at the concentrations tested. CEE-OC and AgNPs-OC inhibited biofilm formation but had no effect on established biofilms. Molecular docking analysis suggested a potential interaction between RA and the NorA efflux pump protein. The results indicated that O. Campechianum extract and biosynthesized silver nanoparticles may represent promising antimicrobial alternatives, although further studies are needed to elucidate the mechanisms underlying their activity.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148697445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diurnal dynamics of maize gene expression is associated with phyllosphere microbiome composition.","authors":"Renato Augusto Corrêa Dos Santos, Kelly Hidalgo-Martinez, Jorge Mario Muñoz-Perez, Daniel Joseph Laspisa, Chenxin Li, Lucas William Mendes, Diego Mauricio Riaño-Pachón, Jason G Wallace","doi":"10.1007/s10123-026-00875-4","DOIUrl":"https://doi.org/10.1007/s10123-026-00875-4","url":null,"abstract":"<p><p>Bacterial communities play important roles in the plant phyllosphere. Both microbial communities and their hosts exhibit endogenous circadian rhythms while simultaneously responding to environmental changes across the diurnal cycle. However, the interaction between the host and microbiome is still poorly understood. Here, we exploit paired sequencing data of host transcriptome and microbiome derived from diverse maize genotypes in field conditions and under two contrasting diurnal periods. Expression patterns of known maize circadian clock genes were consistent with the expected sampling phases. Groups of co-expressed genes that responded to diurnal periods were associated with nucleic acid-binding, heat stress responses, and photosynthesis. Microbiome analysis revealed only modest differences in alpha diversity between midday and midnight samples. However, beta diversity indicated a significant shift in community composition. Co-occurrence network analysis identified keystone taxa specific to each time point, suggesting time-dependent ecological roles within the phyllosphere microbiome. Cross-correlation analyses between host gene expression and bacterial taxon abundance revealed a greater number of host-microbe associations during the night. Several canonical circadian clock genes significantly correlated with microbial taxa. Our findings provide initial evidence for diurnal associations between host gene expression and leaf-associated bacteriome, suggesting that maize diurnal transcriptional dynamics, including the activity of circadian clock genes, may contribute to shaping the composition and functional potential of the phyllosphere microbiome.</p>","PeriodicalId":14318,"journal":{"name":"International Microbiology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148678647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}