Folia Microbiologica[JOURNAL]
Sun
200 papers
Comparative assessment of antibacterial, antifungal, and cytotoxic activities of ceragenins CSA-44 and CSA-131 against endodontic pathogens.
Aslantas K, Oz C, Taghizadehghalehjoughi A … +4 more , Genc S, Erdogan AS, Savage PB, Adiguzel MC
Folia Microbiol (Praha) · 2025 Dec · PMID 41452448 · Publisher ↗
Cationic steroid antimicrobials (CSA-ceragenin), which includes CSA44 and CSA 131, constitute a novel family of antimicrobial drugs. This study aims to examine the antibacterial and antifungal properties of CSA-44 and CS...
Cationic steroid antimicrobials (CSA-ceragenin), which includes CSA44 and CSA 131, constitute a novel family of antimicrobial drugs. This study aims to examine the antibacterial and antifungal properties of CSA-44 and CSA-131 against Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Enterococcus faecalis, and Candida albicans. Additionally, the cytotoxic effects of both compounds were addressed using dental pulp stem cell lines. The CSA-44 compound with a concentration of 0.05% yielded the lowest minimum inhibitory concentration (MIC) of 0.04 µg/mL against E. faecalis. The minimum inhibitory concentration (MIC) values for all concentrations of CSA-44 and CSA-131 against S. aureus ranged between 2.50 and 5.00 µg/mL. Inhibitory action against C. albicans was found to be most pronounced in CSA-131 and CSA-44. The 0.2% of CSA-44 yielded the highest minimum bactericidal concentration (MBC) value of 5.00 µg/mL against S. aureus. The 1xMIC of CSA-44 (0.2%) decreased the bacterial load against E. faecalis at 3 h, even though the same effect was recorded at 6 h against S. aureus. CSA-44 and CSA-131 prevented the growth at 1.5xMIC at 3 h, whereas 1xMIC concentration inhibited the growth at 6 h for all tested microorganisms. The lowest viability was observed with CSA-131 (0.2% 100%), whereas CSA-44 shows lower toxicity than CSA-131 at the same dose. This study provides the first comparative evaluation of the antibacterial, antifungal, and cytotoxic properties of CSA-44 and CSA-131 against clinically relevant endodontic pathogens, offering novel insight into the therapeutic potential of ceragenins in dental applications.
Anti-biofilm potential of Matricaria chamomilla against tetra species representative gut commensals.
Mohanasundaram M, Kandaswamy K, P B H … +2 more , Subramani R, Pushparaj C
Folia Microbiol (Praha) · 2025 Dec · PMID 41428150 · Publisher ↗
In this study, we investigated the effects of supratherapeutic concentrations of M. chamomilla extract on a tetra-species biofilm model comprising Escherichia coli, Enterococcus faecalis, Lactobacillus plantarum, and Lac...
In this study, we investigated the effects of supratherapeutic concentrations of M. chamomilla extract on a tetra-species biofilm model comprising Escherichia coli, Enterococcus faecalis, Lactobacillus plantarum, and Lactobacillus fermentum. Phytochemical screening and GC–MS analysis revealed multiple bioactive compounds, including alkaloids and flavonoids, with potential anti-biofilm activity. Dose-dependent exposure to the extract resulted in a marked reduction in biofilm biomass and cell viability. At 30 µg/mL, biofilm inhibition reached approximately 52–80%, while viable cell counts decreased by more than 55%. FE-SEM confirmed distinct disruption of biofilm structure, and 16S rRNA sequencing indicated a decline in microbial diversity, with the Shannon index falling from 1.1 to 0.9 and observed OTUs decreasing from ~ 200 to ~ 150. These findings suggest that M. chamomilla is generally regarded as beneficial, excessive supplementation may adversely affect gut microbial composition and biofilm stability, highlighting the need for careful use under appropriate guidance.
Quorum quenching pathoblockers from bacteria: an alternative approach for bacterial infection management.
Vijayan NK, Tanimu H, Sukumaran BO
Folia Microbiol (Praha) · 2026 Apr · PMID 41428149 · Publisher ↗
Antibiotic resistance in bacterial pathogens has reached a crisis stage and has led to fears of a “post-antibiotic era”. To combat this, current approach focuses on indirect attack on bacteria by disrupting their communi...
Antibiotic resistance in bacterial pathogens has reached a crisis stage and has led to fears of a “post-antibiotic era”. To combat this, current approach focuses on indirect attack on bacteria by disrupting their communication system, quorum sensing (QS). This system comprises small diffusible signalling molecules activating expression of myriad genes that control an array of functions, including biofilm formation, production of virulence factors and development of antibiotic resistance. Gram-positive bacteria utilise peptide derivatives of these signalling molecules, whereas Gram-negative bacteria employ fatty acid derivatives. Majority of bacteria utilise both types to regulate expression of target gene. Recent research has prioritised identifying several compounds from diverse sources that can hinder the signalling systems responsible for bacterial virulence and pathogenicity. QS inhibitor (QSI) should target the signalling circuit and have no effect on other bacterial systems. Major mechanisms involved in QS inhibition include inhibition of signal molecule synthesis, inactivation/enzymatic degradation of signal molecules, interference with signal receptor, and blocking signal transduction cascades. QSI thus decreases/completely inhibits production of virulence factors. Bacterial products as QSI constitute a promising approach in developing anti-virulence therapies, providing a new avenue for combating bacterial infections parallelly improving effectiveness of traditional antibiotics. Exploring a diverse array of bacterial products like secondary metabolites, cell-free extracts, bacteriocins, biosurfactants, and enzymes as QSIs are gaining prominence due to their selectivity, reduced propensity to induce resistance, and capacity to target multiple pathogens. This review comprehends reported research outcomes from this domain in the recent past and highlights the need of future clinical/translational studies.
The interplay between insect gut microbiota and host immunity in the development and dissemination of antibiotic resistance.
Wenbin T, Feng D, Jing L
Folia Microbiol (Praha) · 2026 Apr · PMID 41405666 · Publisher ↗
The escalating crisis of antibiotic resistance presents a formidable challenge to global public health and food security. Insects are increasingly recognized as significant reservoirs and vectors for antibiotic resistanc...
The escalating crisis of antibiotic resistance presents a formidable challenge to global public health and food security. Insects are increasingly recognized as significant reservoirs and vectors for antibiotic resistance genes (ARGs) which inhabit diverse ecosystems. This review explores how the insect gut microbiota contributes to the development and spread of antibiotic resistance, focusing on the mediating role of the host immune system. We outline the structural and functional dynamics of the insect gut microbiome and elaborate on direct mechanisms through which microbiota contribute to resistance, including ARG carriage, enzymatic inactivation of antibiotics, and modulation of host detoxification pathways. Special emphasis is placed on the bidirectional crosstalk between gut microbes and the host immune system: we discuss how immune effectors, particularly antimicrobial peptides (AMPs), exert selective pressures that may enrich resistant taxa, and how microbial metabolites reciprocally regulate immune activity. Key immune signaling pathways-Toll, Immune Deficiency(Imd), and Janus kinase-signal transducer and activator of transcription (JAK-STAT)-are explored for their roles in maintaining microbial homeostasis and modulating resistance phenotypes. We also highlight cutting-edge experimental approaches, including gnotobiotic models and multi-omics technologies, that are essential for elucidating causal relationships. We conclude by highlighting outstanding questions and outlining future research priorities that integrate microbiology, immunology, and computational biology. This review aims to establish a holistic framework for understanding the insect gut as a hotspot for antibiotic resistance evolution and to inspire innovative microbiome-based interventions.
Organic culture of Spirulina: effects of C and N sources on biomass and biomolecules production in linear and helical morphotypes.
Mansouri Z, Lijassi I, Rhazi L … +1 more , Wahby I
Folia Microbiol (Praha) · 2025 Dec · PMID 41385041 · Publisher ↗
The industrial production of spirulina (Spirulina and Arthrospira spp.) demands large amounts of carbon and nitrogen. This becomes challenging as raw material costs increase and the worldwide market shifts toward organic...
The industrial production of spirulina (Spirulina and Arthrospira spp.) demands large amounts of carbon and nitrogen. This becomes challenging as raw material costs increase and the worldwide market shifts toward organic products. In this study, we examined the feasibility and effectiveness of various carbon and nitrogen sources in both helical and linear spirulina cultures. Glucose at 2.5 g/L doubled the growth of linear spirulina, and the trichomes were 50% longer and thicker compared to the control (inorganic carbon). In addition, the obtained biomass contained more protein (95% ± 0.2%) and phycobiliproteins (PBPs) (989 ± 12 mg/g). The helical strain preferred a lower glucose concentration (0.5 g/L), which led to a twofold increase in protein content (77% ± 0.4%). On the other hand, the substitution of NaNO₃ with 1% soybean hydrolysate significantly increased the trichome size (500 μm ± 21.34 μm) and PBPs content (847.78 ± 143.9 mg/g) in the linear strain. When cultivated with 0.05% whey or soybean hydrolysate, the helical strain showed a 3.5-fold increase in protein content and a twofold increase in C-phycocyanin and PBPs levels. These findings highlight the robustness of the linear strain, which efficiently used higher organic inputs, whereas the helical strain responded better to lower concentrations of organic C and N.
Detection and identification of pathogens using agents targeting the bacterial cell wall.
Zhydzetski A, Głowacka-Grzyb Z, Chlebicka K … +1 more , Władyka B
Folia Microbiol (Praha) · 2026 Apr · PMID 41379369 · Full text
The widespread emergence of multidrug-resistant pathogenic bacteria across various environments, healthcare settings, and food industries, combined with the development of new methods to combat them, highlights the need...
The widespread emergence of multidrug-resistant pathogenic bacteria across various environments, healthcare settings, and food industries, combined with the development of new methods to combat them, highlights the need for more precise, rapid, and cost-effective pathogen detection techniques. This is especially important for clinically relevant pathogens, as it allows treatment to begin as quickly as possible, enables more effective targeted therapies to be chosen, helps preserve the effectiveness of current antibacterial agents, and prevents infections from water- and foodborne bacterial pathogens. Currently, many methods can accurately identify bacteria at the species or strain level and determine their antibiotic resistance. However, most of these techniques require sample preparation and cell culture beforehand, which can be time-consuming and labor-intensive. This review aims to highlight approaches that focus on identifying bacterial cells-especially pathogenic groups-based on their surface properties. This includes agents such as antibodies, whole phage particles, phage receptor binding proteins, cell wall-binding domains of peptidoglycan hydrolases, and functionalized magnetic nanoparticles. These agents can bind to and recognize peptidoglycan, parts of it, and other cell wall components. Developing detection kits based on these agents could enable the rapid detection of pathogenic bacteria from genera such as Acinetobacter, Bacillus, Campylobacter, Clostridium, Enterococcus, Klebsiella, Listeria, Pseudomonas, Salmonella, Shigella, Staphylococcus, Streptococcus, Vibrio, and Yersinia. These methods also offer the potential to distinguish these infectious pathogens from each other and from bacteria of the natural microbiota. Detection typically takes from a few minutes to several hours, with a broad detection range depending on the pathogen species, the detecting agent, and the technique used.
Bacterıal pathogens ın ventılator-assocıated pneumonıa; molecular assessment of resıstance profıles.
Çam B, Hi̇zmali̇ L, Sevi̇m E … +1 more , Akyol R
Folia Microbiol (Praha) · 2025 Dec · PMID 41369836 · Publisher ↗
Ventilator-associated pneumonia (VAP) is the most common infection encountered in intensive care units and is closely linked with elevated mortality, morbidity, and healthcare expenditure. The predominant pathogens respo...
Ventilator-associated pneumonia (VAP) is the most common infection encountered in intensive care units and is closely linked with elevated mortality, morbidity, and healthcare expenditure. The predominant pathogens responsible for VAP are multidrug-resistant (MDR) Gram-negative bacteria, including Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli. This study aimed to investigate the molecular antibiotic resistance profiles of bacterial isolates from hospital-acquired VAP cases. Conducted between 30 November 2022 and 30 November 2023 at Kırşehir Training and Research Hospital, resistance genes were identified using Polymerase Chain Reaction (PCR), while clonal relatedness and genotyping were assessed through Repetitive Extragenic Palindromic-PCR (rep-PCR) and Multi-Locus Sequence Typing (MLST). The most frequently isolated organisms were A. baumannii (46.2%), K. pneumoniae (42.3%), and P. aeruginosa (7.7%). A. baumannii strains exhibited 100% resistance to ciprofloxacin and carbapenems, and 70.83% to colistin. K. pneumoniae strains demonstrated 94.73% resistance to carbapenems and 100% to piperacillin-tazobactam and colistin. Molecular analyses identified bla, bla, bla, bla, bla, and bla in A. baumannii, and bla, bla, bla, bla, bla, and bla in K. pneumoniae. Nine isolates (17%) were identified as transconjugants. MLST analysis revealed K. pneumoniae ST2096 and A. baumannii ST2 as predominant. Clones not previously reported in Türkiye A. baumannii ST78 and K. pneumoniae ST45, ST437, and ST1128 were also detected. This study provides a comprehensive molecular characterisation of VAP pathogens based on an extensive dataset. The results underscore the need for stricter infection control, restrained use of broad-spectrum antibiotics, and ongoing surveillance of resistance mechanisms.
Epstein-Barr virus and human MiRNAs crosstalk: orchestrating latency, lytic cycle, and immune system modulation.
Mansour RM, El-Sayyad GS, Hemdan M … +11 more , Rizk NI, Abdel Mageed SS, Mohammed OA, Mahdy A, Abuelhaded K, Farag SA, Shahin RK, Nassar YA, El-Shora HM, Amin R, Doghish AS
Folia Microbiol (Praha) · 2026 Apr · PMID 41369835 · Publisher ↗
Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus that establishes lifelong latency in its host and is associated with a range of malignancies and immune-related disorders. This review examines the complex inter...
Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus that establishes lifelong latency in its host and is associated with a range of malignancies and immune-related disorders. This review examines the complex interactions between EBV and microRNAs (miRNAs), small, non-coding RNAs that regulate gene expression at the post-transcriptional level. It focuses on EBV-encoded miRNAs derived from the BHRF1 and BART clusters, detailing their distinct functions during different latency phases and viral reactivation. These miRNAs facilitate immune evasion, modulate cell cycle progression, apoptosis, and differentiation, and promote cellular environments that favor viral persistence and oncogenesis. EBV also disrupts host miRNA networks, altering gene expression and immune regulation, which contributes to tumor development in diseases such as Burkitt's lymphoma, nasopharyngeal carcinoma, Hodgkin's lymphoma, and post-transplant lymphoproliferative disorders, and has additionally emerged as a leading etiological factor in multiple sclerosis. Furthermore, the review highlights how viral and host miRNAs jointly modulate immune checkpoints, antiviral defense mechanisms, and the tumor microenvironment. It concludes by summarizing recent progress in miRNA-based diagnostics and therapeutics, underscoring their potential for advancing personalized medicine in EBV-associated pathologies.
Probiotic characteristics and safety evaluation of acid-tolerant lactic acid bacteria isolated from Suancai, a popular fermented vegetable in Northeast China.
Wang L, Fu Y, Zhou G … +3 more , Zhang M, Lin J, Guo L
Folia Microbiol (Praha) · 2025 Dec · PMID 41348297 · Publisher ↗
This study aimed to isolate acid-tolerant lactic acid bacteria from Suancai, a traditional Chinese fermented vegetable, and evaluate their potential and safety as candidate probiotics. Fifteen dominant lactic acid bacter...
This study aimed to isolate acid-tolerant lactic acid bacteria from Suancai, a traditional Chinese fermented vegetable, and evaluate their potential and safety as candidate probiotics. Fifteen dominant lactic acid bacteria strains were isolated from spontaneously fermented Suancai, and four isolates were selected based on their tolerance to acid and bile, as well as their autoaggregation, coaggregation, cell surface hydrophobicity, and adhesion capabilities. Based on 16S rRNA and pheS gene sequence analyses, the four strains were identified as Lactiplantibacillus plantarum (strain S5) and Levilactobacillus brevis (strains S1, H1, and H2). These strains were further evaluated for multiple in vitro probiotic properties. All four exhibited cholesterol removal capacity, DPPH and hydroxyl radical scavenging activity, gamma-aminobutyric acid production, and nitrite degradation ability. α-Glucosidase inhibitory activity was observed in three strains, with the exception of Levilactobacillus brevis S1. Additionally, all strains displayed antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Salmonella paratyphi B. Safety assessment revealed that the strains were sensitive to ampicillin, erythromycin, and penicillin, resistant to gentamycin, and negative for indole production and hemolytic activity. In conclusion, the four selected strains demonstrated favorable probiotic characteristics and safety profile, supporting their potential as candidate probiotics for functional food application.
Antimicrobial and antibiofilm activities of Ag/AgO-anchored CeO nanosphers: reaction mechanism determination.
Mabrouk SS, Al-Habeeb RS
Folia Microbiol (Praha) · 2025 Dec · PMID 41326927 · Publisher ↗
This study focuses on preparing Ag/AgO nanoparticles (NPs) by a one-pot method and anchors the CeO nanospheres as antimicrobial agents. XRD patterns revealed the successful preparation of Ag/AgO/CeO NPs. Additionally, SE...
This study focuses on preparing Ag/AgO nanoparticles (NPs) by a one-pot method and anchors the CeO nanospheres as antimicrobial agents. XRD patterns revealed the successful preparation of Ag/AgO/CeO NPs. Additionally, SEM and TEM images exhibited that the Ag/AgO/CeO NPs are aggregated with a spherical shape in the nanoscale range. By looking at how well they fight bacteria, the smallest amount needed to stop growth, and their ability to prevent biofilm formation, we tested how effective Ag/AgO/CeO NPs are against bacteria that cause serious infections and unicellular harmful fungi. The membrane leakage experiment was used to investigate a possible mechanism of antibacterial behavior. The synthesized Ag/AgO-CeO NPs showed strong antimicrobial effects against all the bacteria and unicellular fungi we tested. At a concentration of 250 μg/mL of CeO NPs, the maximum ZOI of approximately 19.0 mm was seen against Candida albicans, and 17.0 mm against Bacillus subtilis at the same concentration. E. coli was detected in the 16.0 mm ZOI during the action against K. pneumoniae. On the other hand, the largest ZOI of roughly 26.0 mm was tested against B. subtilis and C. albicans at 250 μg/mL of Ag/AgO NPs. This was followed by ZOIs of 21.0 mm against C. tropicalis, 20.0 mm against K. pneumoniae and E. cloacae, and 19.0 mm against S. epidermidis. The Ag/AgO-CeO NPs showed a range of activities at 250 μg/mL against B. subtilis (34.0 mm ZOI) and C. albicans (33.0 mm ZOI). Ag/AgO-CeO NPs, however, had the same effect on E. coli, P. fluorescens, and S. epidermidis (25.0 mm ZOI). The final result showed that Ag/AgO-CeO NPs exhibited 22.0 mm ZOI activity against K. pneumoniae and 21.0 mm ZOI activity against E. cloacae. The promising findings suggested that the Ag/AgO-CeO NPs can be used against pathogenic bacteria in biomedical fields.
Dual potential of Bacillus pumilus PAD5 isolated from Eryngium foetidum: biocontrol of Sclerotium rolfsii and growth promotion in rice.
Pandey PK, Yadav RNS, Samanta R … +2 more , Singh AK, Singh S
Folia Microbiol (Praha) · 2025 Dec · PMID 41324876 · Publisher ↗
The endophytic isolate PAD5, derived from Eryngium foetidum L. and identified as Bacillus pumilus strain PAD5 (KX350056), demonstrated remarkable characteristics including phosphate solubilization (7.5 µg/ml), indole-3-a...
The endophytic isolate PAD5, derived from Eryngium foetidum L. and identified as Bacillus pumilus strain PAD5 (KX350056), demonstrated remarkable characteristics including phosphate solubilization (7.5 µg/ml), indole-3-acetic acid (IAA) production (31.13 µg/ml), biofilm formation, siderophore, hydrogen cyanide (HCN), and exo-polysaccharide production. It exhibited robust growth on nitrogen-free media, high salt conditions (6%), and low pH (5.0). The isolate showed potent antagonistic activity against Sclerotium rolfsii. Gas chromatography-mass spectrometry (GC-MS) analysis of the crude extract revealed the presence of five major and 19 minor active compounds. When applied in conjunction with the pathogen (SrBp), the PAD5 isolate remarkably enhanced rice growth after 20 days of transplanting, recording substantial increases over the pathogen (Sr) treatment shoot length by 175.8%, shoot fresh weight by 193.5%, shoot dry weight by 161.0%, root length by 106.5%, root fresh weight by 114.3%, and root dry weight by 129.2%. These pronounced improvements indicating PAD5's strong potential in promoting plant growth even under pathogen-induced stress. Additionally, the PAD5 isolate induced systemic response and enhanced host defense physiological activities, as evidenced by elevated plant defense enzyme such as Phenylalanine ammonia lyase (PAL), Total phenol content (TPC), Polyphenol oxidase (PPO), and Superoxide dismutase (SOD) enzyme activities in seedlings treated with either isolate PAD5 alone or in combination with the pathogen (SrBp).
α-Bromocinnamaldehyde combats ESKAPE pathogens through dual bactericidal mechanism.
Zhang T, Fang C, Wang M … +4 more , Song Z, Zhang Y, Zhou Y, Hou Z
Folia Microbiol (Praha) · 2025 Nov · PMID 41307646 · Publisher ↗
Trans-cinnamaldehyde (CA), a natural compound from cinnamon oil, is known for its broad-spectrum but limited antibacterial activity. In this study, we synthesized and evaluated a series of CA derivatives, identifying α-B...
Trans-cinnamaldehyde (CA), a natural compound from cinnamon oil, is known for its broad-spectrum but limited antibacterial activity. In this study, we synthesized and evaluated a series of CA derivatives, identifying α-Bromocinnamaldehyde (BCA) as the most potent antibacterial agent against ESKAPE pathogens. Through minimum inhibitory concentration (MIC) assays and a detailed structure-activity analysis, we determined that BCA’s enhanced antibacterial potency is due to the α-bromine substitution, the aldehyde group, and the conjugated double bond. In an in vivo septic mouse model infected with NDM-1-producing E. coli, BCA treatment significantly improved survival rates, and no acute renal or liver toxicity was observed at therapeutic doses. Mechanistic studies, including scanning electron microscopy, fluorescence microscopy, Gram staining, light-scattering assays for FtsZ polymerization, and GTP hydrolysis assays, have elucidated that BCA exerts its bactericidal effects through a dual-mechanism approach. Firstly, BCA increases membrane permeability, disrupting the integrity of the bacterial cell membrane. Secondly, it inhibits bacterial cell division, likely by interfering with the polymerization of FtsZ, a key protein involved in cell division, and affecting GTP hydrolysis processes essential for cell division progression. These findings highlight BCA’s dual bactericidal mechanisms and support its potential as a promising therapeutic agent for treating multidrug-resistant bacterial infections.
Characterization of novel lactic acid bacteria from Algerian ecosystems with probiotic potential and antioxidant-antidiabetic properties.
Mahrouk A, Mosbah A, Chaouche NK … +5 more , Hamdi M, Slimani A, Badaoui MYZ, Amrani Y, Akkal S
Folia Microbiol (Praha) · 2025 Nov · PMID 41307645 · Publisher ↗
The current investigation aimed to highlight the potential of probiotics isolated from lactic acid bacteria of different Algerian ecosystems as antioxidant and antidiabetic agents. Fifty-four strains from different ecosy...
The current investigation aimed to highlight the potential of probiotics isolated from lactic acid bacteria of different Algerian ecosystems as antioxidant and antidiabetic agents. Fifty-four strains from different ecosystems were isolated anaerobically. The subsequent steps involved comprehensive characterization and in vitro assessments, including assays for scavenging DPPH and ABTS•+ radicals, measuring ferric ion reducing power (FRAP), and assessing the impact of the strains on the α-amylase enzyme. Additionally, the hydrophobicity potential, aggregation and coaggregation capacities, antibacterial activity, and absence of hemolytic activity were investigated. Ten (10) out of the fifty-four (54) strains exhibited characteristics of probiotics like resistance at a low gastric pH (2.0-3.0) (> 55% survival rate) and survival under different concentrations of NaCl and bile salts 0.3%-1% (> 80% survival rate). All the isolated strains exhibited high hydrophobicity potential, remarkable aggregation and coaggregation capacities, and antibacterial activity but no hemolytic activity. Because of the antioxidant capacity of the selected strains, every strain seems to be capable of efficiently scavenging DPPH and ABTS•+ radicals, superoxide dismutase and hydroxyl radical scavenging activity, and high resistance to HO. The findings of this study strongly suggest that the identified strains hold significant promise as potential probiotic candidates. Their observed capabilities make them particularly valuable in addressing oxidative stress and associated conditions, such as diabetes.
Rhizosphere bacteria improve zinc bioavailability and nutritional quality of rice in zinc-deficient soils of eastern India.
Bharati N, Saha N, Sen A … +1 more , Samanta A
Folia Microbiol (Praha) · 2025 Nov · PMID 41296219 · Publisher ↗
Around 55% of the rice soils in West Bengal, the highest rice-producing state in eastern India, are deficient in zinc (Zn), leading to Zn malnutrition among its population due to huge reliance on rice for calories. The p...
Around 55% of the rice soils in West Bengal, the highest rice-producing state in eastern India, are deficient in zinc (Zn), leading to Zn malnutrition among its population due to huge reliance on rice for calories. The present investigation tested the feasibility of native zinc-solubilizing bacteria (ZnSB) to improve the Zn bioavailability and subsequent biofortification of rice grown in Gangetic alluvial soils that are low in Zn. Initially, 56 bacterial isolates were recovered from the rice rhizosphere of Zn-deficient soils, and 20 were found to solubilize insoluble Zn in agar plates. Among the 20 bacterial strains, Zn solubilizing potential was maximum for the isolate Burkholderia cepacia strain K1. It showed 775% Zn solubilizing efficiency, releasing 576.67 µg/mL Zn from zinc oxide in liquid medium and lowering the solution pH by 2.87 units. Principal component analysis revealed that K1, along with strains K2 and B4, produced the best results when testing Zn solubilization ability alongside indole-3-acetic acid production (18.5-24.6 µg/mL) and metabolic adaptability for all tested carbon sources. In the pot experiment, root biopriming with K1 significantly increased soil available Zn by 105.8%, rice grain yield by 19.9%, and grain Zn concentration by 36.3% over the control treatment, which produced 12.69 g grain/pot with a Zn concentration of 24.33 µg/g grain. The experimental findings illustrate that native ZnSB strains K1, K2, and B4 shows promise for reducing Zn deficiency in rice fields as a sustainable solution while managing malnutrition and soil health.
Comparison of antibiotic resistance, virulence determinants, and biofilm formation in Pseudomonas aeruginosa isolated from intestinal carriers and clinical samples.
Mehboodi M, Saffari F, Hosseini-Nave H … +2 more , Ahmadi B, Ahmadrajabi R
Folia Microbiol (Praha) · 2025 Nov · PMID 41284194 · Publisher ↗
Pseudomonas aeruginosa is an important opportunist pathogen responsible for community-acquired and nosocomial infections. The intestinal carriage of P. aeruginosa is likely due to its opportunistic nature. The aim of thi...
Pseudomonas aeruginosa is an important opportunist pathogen responsible for community-acquired and nosocomial infections. The intestinal carriage of P. aeruginosa is likely due to its opportunistic nature. The aim of this study was to compare phenotypic and genotypic characteristics of P. aeruginosa recovered from stool of intestinal carriers with those isolated from various clinical specimens. Twenty- four fecal P. aeruginosa isolates obtained from 148 stool samples (74 healthy individuals and 74 patients with colonic disease) and 26 clinical P. aeruginosa isolates recovered from various clinical specimens other than stool, were investigated. Antimicrobial susceptibility, biofilm-forming ability using phenotypic methods and presence the exoY, algD, toxA, exoS, exoU, lasB, exoT genes were determined using polymerase chain reaction. The frequency of fecal carriage of P. aeruginosa was determined 16.2%. All fecal isolates were susceptible to ceftazidime and colistin, whereas all clinical isolates were susceptible only to colistin. There were no significant differences in multidrug- resistant (MDR) phenotypes between the clinical and fecal isolates. No significant differences in biofilm production were observed among isolates from healthy individuals compared with those from patients with colonic disease. However, differences were observed between clinical and fecal isolates regarding the presence of the algD and exoU genes (P ≤ 0.05). A significant difference was also found in the present of the exoU gene between MDR fecal and MDR clinical isolates (P = 0.007). The high prevalence of virulence factors in both fecal and clinical isolates emphasizes the importance of fecal P. aeruginosa as same as clinical isolates.
Genomic characterization of high-level efflux pump overexpression in Pseudomonas aeruginosa clones with epidemic potential.
Lin X, Guo Z, Wang W … +2 more , Wang D, Ma L
Folia Microbiol (Praha) · 2025 Nov · PMID 41273498 · Publisher ↗
The concerted overexpression of multiple efflux pumps in Pseudomonas aeruginosa now represents a key driver of multidrug resistance (MDR), progressively undermining the efficacy of conventional antibiotic therapies. The...
The concerted overexpression of multiple efflux pumps in Pseudomonas aeruginosa now represents a key driver of multidrug resistance (MDR), progressively undermining the efficacy of conventional antibiotic therapies. The transferability of plasmid pXM8-2 was assessed by conjugation experiments. The antimicrobial susceptibility of strains P113, P118, T117, and XM8 was determined using the BioMerieux VITEK-2 system in conjunction with the disk diffusion method. β-lactamase or carbapenemase production was detected per CLSI guidelines. Efflux pump gene expression was quantified by quantitative real-time PCR, and O-antigen serotyping was performed phenotypically with specific antisera and genotypically via bioinformatics tools. Whole-genome sequencing using Illumina and nanopore platforms revealed a comprehensive profile of antibiotic resistance genes. Phenotypically, strains P113, P118, and T117 were resistant to all antibiotics tested, consistent with their genotypes. In contrast, strain XM8, which also harbored numerous resistance genes, remained susceptible to colistin. All attempts to transfer the pXM8-2 plasmid via conjugation were unsuccessful. The studied strains exhibited a MDR phenotype, primarily conferred by the overexpression of efflux pumps (e.g., MexAB-OprM, MexCD-OprJ, MexXY, MexEF-OprN) and inactivation of the oprD. Genotypic characterization identified strains P113, P118, and T117 as ST11/O3 (ExoS/ExoU), whereas XM8 was ST385/O6 (ExoS/ExoU). Evolutionary analysis indicated the global dissemination of XM8-like clones, with a pronounced peak in 2023-2024. Crucially, the MDR of XM8 was further exacerbated by antibiotic resistance genes located on its non-transferable plasmid, pXM8-2. Enhanced surveillance and preemptive containment measures are urgently needed to mitigate the public health threat posed by these resistant lineages.
Purification and biochemical characterization of a novel thermostable acid α-amylase from Geotrichum candidum PO27 with industrial application.
Chaib I, Dakhmouche-Djekrif S, Lorrai S … +2 more , Cannella D, Nouadri T
Folia Microbiol (Praha) · 2025 Nov · PMID 41273497 · Publisher ↗
Algeria imports all of its enzymes for use in different fields, which causes a serious economic problem as the cost of these enzymes is continuously rising. New enzymes with efficient and unique properties are always so...
Algeria imports all of its enzymes for use in different fields, which causes a serious economic problem as the cost of these enzymes is continuously rising. New enzymes with efficient and unique properties are always sought to meet the specific needs of various industry sectors. This study aimed to investigate the purification and characterization of α-amylase from the Algerian Geotrichum candidum PO27, and its potential application as a desizing agent in the textile industry. This enzyme was purified 6.73-fold in two process steps: concentration by ultrafiltration, followed by exclusion chromatography, achieving a final recovery of 9.1%. The results showed that its molecular weight was estimated for the first time by SDS-PAGE as 19.2 kDa. Physicochemical characterization of purified enzyme revealed optimal activity at pH 5 and 70 °C, thermostability properties, and high stability in the presence of Mg and Tween 80. It was also found to be resistant to surfactants and organic solvents. The enzyme exhibited a maximum velocity (V) of 588.23 U/mL and a high affinity for soluble starch, with a Michaelis Menten constant (K) of 0.114 mg/mL, values not previously reported. The enzyme showed notable efficacy in cotton desizing at room temperature, demonstrating its potential for efficient, low-cost industrial applications.
Age and anatomical site shape the gastrointestinal bacterial communities of captive American crocodiles (Crocodylus acutus).
López-Espinoza JU, Peinado-Guevara LI, Rodríguez-Sala BG … +1 more , Campista-León S
Folia Microbiol (Praha) · 2025 Nov · PMID 41273496 · Publisher ↗
Bacterial communities in the gastrointestinal tract (GIT) play a critical role in the health and physiology of vertebrates, responding to multiple intrinsic and extrinsic factors that modulate their structure and functio...
Bacterial communities in the gastrointestinal tract (GIT) play a critical role in the health and physiology of vertebrates, responding to multiple intrinsic and extrinsic factors that modulate their structure and function. However, little is known about how these factors are associated with the dynamics and composition of these bacterial communities, especially in crocodilians. In this study, the structure of oral and cloacal bacterial communities in the GIT of Crocodylus acutus was examined through 16 S rRNA gene sequencing. The influence of factors such as age, sex, season, and anatomical location was evaluated. A total of 54 oral and cloacal samples from 27 adult and juvenile specimens from a captive population in Sinaloa, Mexico, were analyzed. Forty-two bacterial phyla were identified, with Pseudomonadota, Bacillota, and Bacteroidota being the most abundant. Significant differences in bacterial composition and diversity were detected between age groups and body regions, with greater diversity in adult specimens. Functional analysis predicted a predominance of metabolic pathways associated with amino acid and carbohydrate metabolism. This study establishes that age and anatomical site are key determinants in the structure of bacterial communities in C. acutus in captivity, providing the first comprehensive characterization for the species. These results establish a fundamental baseline for future comparative research with wild populations, as well as for the development of management and conservation strategies.
Antimicrobial photodynamic therapy against multidrug-resistant Staphylococcus aureus using aluminum chloride phthalocyanine nanoemulsion: in vitro and in vivo studies.
Mehrbakhsh S, Rezaee M, Ghandehari F … +2 more , Fatemi M, Ahadi AM
Folia Microbiol (Praha) · 2025 Nov · PMID 41266868 · Publisher ↗
Antimicrobial photodynamic therapy is a promising approach for treating superficial infections caused by resistant strains. This study evaluated the effectiveness of antimicrobial photodynamic therapy against multidrug-r...
Antimicrobial photodynamic therapy is a promising approach for treating superficial infections caused by resistant strains. This study evaluated the effectiveness of antimicrobial photodynamic therapy against multidrug-resistant Staphylococcus aureus using aluminum chloride phthalocyanine encapsulated in nanoemulsion (NE/ClAlPc) in a rat burn wound model under in vitro and in vivo conditions. In vitro, NE/ClAlPc-mediated antimicrobial photodynamic therapy was assessed for bacterial logarithmic reduction, inhibition of biofilm metabolism, and cytotoxicity on mouse skin fibroblasts (L929) using the MTT assay at 6, 12, and 24 h. Cell migration was evaluated via the scratch wound assay. In vivo, seven groups of male rats with burn wounds were treated with antimicrobial photodynamic therapy. Wound areas were measured, and skin biopsies were analyzed for histological changes and mRNA expression levels of FGF1, TGF-β1, and GPX1 genes using real-time PCR. Results showed an 8-log reduction in the survival of multidrug-resistant S. aureus and a 60% reduction in biofilm metabolism. NE/ClAlPc-mediated antimicrobial photodynamic therapy inhibited bacterial growth, stimulated fibroblast migration, and accelerated wound healing. Histological analysis confirmed reduced wound areas and faster healing. Real-time PCR exposed strong GPX1 mRNA expression post-injury, elevated FGF1 mRNA in untreated wounds, and increased TGF-β1 mRNA after laser treatment. NE/ClAlPc-mediated antimicrobial photodynamic therapy demonstrated potent antibacterial and antibiofilm activity against multidrug-resistant S. aureus, significantly reducing burn wound areas and promoting healing in rats. This treatment shows promise as an alternative for eradicating multidrug-resistant bacteria.
Cellular and molecular outcomes of Pseudomonas putida KT2440 exposure to aluminium.
Abdeljelil N, Ben Miloud Yahia N, Landoulsi A … +4 more , Chatti A, Wattiez R, Van Houdt R, Gillan D
Folia Microbiol (Praha) · 2025 Nov · PMID 41264166 · Publisher ↗
Despite being an abundant metal, nature evolved to exclude aluminium (Al) from living organisms. In addition, the complex chemistry of this element makes it a challenging case for researchers. At physiological pH, Al has...
Despite being an abundant metal, nature evolved to exclude aluminium (Al) from living organisms. In addition, the complex chemistry of this element makes it a challenging case for researchers. At physiological pH, Al has strong affinity to oxygen donors and negatively charged molecules such as proteins, nucleotides and cellular components bearing phosphates and carboxylic groups. Because of its widespread industrial use, living organisms are increasingly exposed to soluble forms of this light metal and environmental bacteria are in the front line. In this work, we show the disruptive effect of Al at physiological pH on the cellular morphology of Pseudomonas putida KT2440 and on the integrity of its mature biofilms. Proteomic studies revealed that an exposure to 0.78 mM of the aluminium compound used in this study significantly affected key proteins and enzymes involved in the TCA cycle, the respiratory chain, the maintenance of the cell's membrane and the transmembrane transport systems. The expression levels of major metal-resistance proteins (e.g., P-type ATPases and RND tripartite efflux pumps) was not affected, contrary to those of methyltransferases and systems involved in the metabolism of phosphate that might be involved in the maintenance of low Al concentration in the cytoplasm.
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