Folia microbiologica最新文献

{"title":"Weissella paramesenteroides M4: Optimization of bioprocesses, antioxidant property, and a potentially probiotic strain with in vitro activity against Cutibacterium acnes.","authors":"Heloísa Carneiro Colares, Tuânia Natacha Lopes Silva, Vinícius Souza Tarabal, Hiure Gomes Ramos Meira, Jéssica Ferreira Cardoso, Adriano Guimarães Parreira, José Antônio da Silva, Gisele Rodrigues da Silva, Juliana Teixeira de Magalhães, Daniel Bonoto Gonçalves, Paulo Afonso Granjeiro","doi":"10.1007/s12223-026-01585-0","DOIUrl":"https://doi.org/10.1007/s12223-026-01585-0","url":null,"abstract":"<p><p>The skin microbiota is linked to conditions such as acne. As antibiotic resistance limits the effectiveness of conventional treatments, microbiome-based strategies are needed. This study aimed to optimize the biomass production of Weissella paramesenteroides M4, evaluate its antioxidant properties, and assess its efficacy in a topical gel formulation against Cutibacterium acnes. Growth dynamics were established, followed by biomass optimization using fractional factorial and central composite rotatable designs with deproteinized whey as a sustainable substrate. Optimization increased biomass production by 974% (reaching 8.7 × 10¹⁰ CFU/mL, equivalent to 2.031 g/L dry weight under validated conditions); significant variables included yeast extract, peptone, and MnSO₄. Antioxidant assays showed activities of 80% (intact cells) and 61% (lysed cells), with 82% relative growth under 1.0 mM H₂O₂ oxidative stress (estimated spectrophotometrically). Notably, W. paramesenteroides M4 selectively inhibited the pathogen C. acnes ATCC 6919 in vitro without affecting the commensal S. epidermidis ATCC 12,228 in vitro. A cosmetic gel containing the strain maintained antimicrobial efficacy and stability for 15 days at 4 °C. W. paramesenteroides M4 demonstrates high bioprocess efficiency, robust antioxidant potential, and selective in vitro antimicrobial activity. The formulated gel containing the candidate probiotic strain retained antimicrobial activity under refrigeration during storage and shows potential for innovative topical applications, providing a preliminary foundation for alternative acne management. This research provides a sustainable framework for high-yield probiotic production using industrial by-products and introduces a potentially probiotic lactic acid bacterium with selective in vitro activity, representing a promising candidate for alternative acne treatment, addressing a significant gap in current dermatological therapies.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148988563","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":"Effects of different organic fertilization regimes on soil physicochemical properties and bacterial community assembly to promote greenhouse-cultivated Aloe vera L. growth.","authors":"Tongtong Tang, Xing Sun, Weiwei Zhang","doi":"10.1007/s12223-026-01587-y","DOIUrl":"https://doi.org/10.1007/s12223-026-01587-y","url":null,"abstract":"<p><p>Sustainable production of greenhouse-cultivated Aloe vera L. largely depends on soil quality and rhizosphere microbial stability. Organic fertilization is widely applied to improve farmland soil environment, whereas the long-term effects of different organic fertilizer regimes on soil fertility, plant growth and rhizosphere bacterial community assembly remain unclear in intensive Aloe vera L. cultivation systems. This 4.5 years greenhouse trial was conducted to systematically investigate the regulatory effects of different organic fertilization practices on soil physicochemical properties, Aloe vera L. growth performance, and rhizosphere bacterial diversity and structure. Four treatments were set up in the experiment, including earthworm manure (QY), aloe-specific organic fertilizer (LY), conventional organic fertilizer (PY), and non-fertilized control (CK). Plant growth traits, soil fertility parameters, and rhizosphere bacterial community composition and diversity were comprehensively determined and compared across treatments. The results showed that long-term application of fertilization treatment significantly improved soil nutrient status, with the soil organic matter (SOM) content increased by 40.76% in QY treatment. Fertilization regimes altered diversity and structure of bacterial communities, while no significant difference in community composition was detected across treatments. The QY and LY treatments increased microbial community heterogeneity, while the PY and CK treatments maintained a relatively stable microbial community structure. SOM and available phosphorus (AP) were identified as the primary edaphic drivers governing phylum-level bacterial community variation. Notably, although the QY treatment showed positive effects on soil quality and metabolites production in Aloe vera L., it reduced leaf width and crown width. These results indicate that QY treatment unsuitable for Aloe vera L. cultivation targeting high yield, whereas it is still applicable for Aloe vera L. production by virtue of its performance in improving soil quality and maintaining microbial ecological stability, which can support the healthy and sustainable cultivation of Aloe vera L.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148982510","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":"Postbiotic-mediated antibiofilm activities of newly isolated LAB strains against cariogenic pathogens.","authors":"Anaswara P A, K Madhavan Nampoothiri","doi":"10.1007/s12223-026-01593-0","DOIUrl":"https://doi.org/10.1007/s12223-026-01593-0","url":null,"abstract":"<p><p>Postbiotics, the metabolites from probiotics, offer a promising approach for controlling oral biofilms through the inhibition of adhesion, degradation of established biofilms, or by exerting antimicrobial effects. This study evaluated the antibiofilm properties of the cell-free supernatants (CFS) of newly isolated Lactiplantibacillus plantarum GS2 and Pediococcus pentosaceus BM1 against cariogenic pathogens Streptococcus mutans and Streptococcus oralis. The antibiofilm activity of concentrated CFS was found to be mediated by heat-stable, protease-resistant bioactive metabolites. pH neutralization of concentrated CFS revealed the effect of non-acidic metabolites on antibiofilm activities. Among the probiotic characteristics, the GS2 strain exhibited higher DPPH scavenging activity (18.76%) and cell-surface hydrophobicity with hexadecane (44.52%), chloroform (63.06%), toluene (38.47%), and benzene (32.27%). Furthermore, both strains exhibited remarkable auto-aggregation and coaggregation properties with oral pathogens. Notably, CFS of GS2 and BM1 exhibited a loss of or weak antimicrobial activity against S. mutans and S. oralis upon pH neutralization, suggesting that the antimicrobial activity is mainly pH-dependent. Interestingly, CFS at their natural and neutralized pH significantly reduced the biomass of pre-formed biofilms (24 h) of S. mutans and S. oralis. In addition, the anti-adherence assay, performed by precoating CFS to the microtiter wells, revealed significant anti-adherence activities (30-40%) against oral pathogens irrespective of their pH. This activity likely indicates the presence of metabolites like biosurfactants that can interfere with surface-pathogen interactions. This study also demonstrated the biocompatibility of neutralized postbiotics in L929 and HGF cell lines, which might be useful for oral applications.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148982594","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":"Synergistic effects of luteolin and Lactobacillus rhamnosus on methicillin-resistant Staphylococcus aureus biofilm inhibition: in vitro and in silico molecular deployment studies.","authors":"Sumeyye Baser, Demet Celebi, Ozgur Celebi, Adem Kara, Cuneyt Turkes","doi":"10.1007/s12223-026-01592-1","DOIUrl":"https://doi.org/10.1007/s12223-026-01592-1","url":null,"abstract":"<p><p>Methicillin-resistant Staphylococcus aureus (MRSA) remains one of the leading causes of healthcare-associated infections due to its remarkable biofilm-forming ability and multidrug resistance, highlighting the urgent need for alternative antimicrobial strategies. The present study investigated the antibacterial, antibiofilm, antivirulence, and cytotoxic effects of luteolin alone and in combination with Lactobacillus rhamnosus bacterial suspension natant against MRSA. Antibacterial activity was evaluated using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), disk diffusion, and fractional inhibitory concentration (FIC) assays. Biofilm inhibition was quantified using the crystal violet method, while the expression levels of biofilm-associated genes (icaA, icaB, icaC, icaD, clfA, clfB, fnbA, and fnbB) were determined by quantitative real-time PCR. Molecular docking analysis was performed to investigate the interaction between luteolin and S. aureus Sortase A (SrtA), and the cytotoxic potential of the treatments was evaluated in human dermal fibroblast (HDF) cells using the WST-8 assay. Luteolin exhibited MIC and MBC values of 128 and 256 µg/mL, respectively, whereas L. rhamnosus bacterial suspension natant also demonstrated antibacterial activity against MRSA. Combination treatment significantly increased the inhibition zone diameter and produced a synergistic interaction with an FIC index of 0.50. Moreover, the combination inhibited biofilm formation by approximately 75%, markedly exceeding the inhibitory effects of either treatment alone. Gene expression analysis revealed dose-dependent modulation of several biofilm-associated genes, particularly suppression of fnbA, suggesting interference with bacterial adhesion mechanisms. Molecular docking demonstrated favorable binding of luteolin to the active site of Sortase A with a predicted binding energy of - 9.220 kcal/mol, supporting its potential antivirulence mechanism. No significant cytotoxicity was observed in HDF cells within the tested concentration range. Collectively, these results demonstrate that luteolin combined with L. rhamnosus bacterial suspension natant represents a promising natural therapeutic strategy for controlling MRSA infections by simultaneously targeting bacterial growth, biofilm formation, and virulence while maintaining acceptable biocompatibility.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148955389","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":"Gut microecology and cardiovascular disease: core pathogenic mechanisms and clinical intervention strategies.","authors":"Dian Yuan, Shuang He, Xiao-Ning Su, Qiao Sun, Yan-Tong Wang, Ming-Xia Li, Xiao-Heng Wu, Ye-Hong Xie, Yan Zhang, Ya-Lu Qin","doi":"10.1007/s12223-026-01583-2","DOIUrl":"https://doi.org/10.1007/s12223-026-01583-2","url":null,"abstract":"<p><p>Cardiovascular diseases (CVDs) remain a leading cause of morbidity and mortality worldwide, and their burden continues to rise. The gut microbiota is a key interface linking host metabolism, environmental exposures, and immunity, and accumulating evidence implicates gut dysbiosis in the pathogenesis, progression, and clinical outcomes of CVDs. Dysbiosis may promote the pathological \"gut-heart axis\" by impairing intestinal barrier integrity, amplifying systemic inflammation, disrupting metabolic homeostasis, and altering immune networks. Microbiota-targeted strategies-including dietary modulation and physical activity, probiotics and prebiotics, fecal microbiota transplantation (FMT), and microbial enzyme or metabolite inhibitors-have yielded promising preclinical results and early clinical signals; however, long-term efficacy, safety, and patient-selection criteria remain uncertain. This review synthesizes evidence on gut microbial alterations and major metabolites, including trimethylamine N-oxide (TMAO), short-chain fatty acids (SCFAs), and lipopolysaccharide (LPS), across atherosclerosis, acute coronary syndrome, hypertension, ischemic heart disease, and heart failure. We compare disease-specific mechanisms, critically appraise therapeutic evidence and safety, and identify priorities for causal, standardized, and clinically meaningful research. These findings provide a mechanistic framework for microbiome-informed prevention and adjunctive management of CVD while emphasizing that microbiota-directed interventions should not replace guideline-directed care.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148944792","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":"Liquid fermentation and an adapted cetyltrimethylammonium bromide (CTAB) method enable sequencing-grade DNA extraction from Phanerodontia australis.","authors":"Lorena Resende Oliveira, Ariany Rosa Gonçalves, Tereza Cristina de Oliveira Borba, Marcio Vinicius de Carvalho Barros Cortes, Marta Cristina Corsi de Filippi","doi":"10.1007/s12223-026-01591-2","DOIUrl":"https://doi.org/10.1007/s12223-026-01591-2","url":null,"abstract":"<p><p>High-quality genomic DNA extraction from basidiomycete fungi remains challenging due to polysaccharide co-purification and nuclease-mediated DNA degradation. We systematically compared 22 experimental conditions combining five DNA extraction methods (one Dellaporta-based method, three CTAB-based variants, and one commercial kit) with five mycelium preparation techniques (scalpel scraping, fungal suspension, silica bead homogenization, liquid fermentation, and liquid nitrogen treatment) for Phanerodontia australis (BRM62389). DNA quality was assessed by 1% agarose gel electrophoresis, NanoDrop spectrophotometry, and Qubit fluorimetry. The optimal protocol combined liquid-fermentation mycelium with an adapted CTAB method, yielding Qubit-quantified concentrations of 34.2 and 62.6 ng/µL (samples S21 and S22), 260/280 ratios of 2.06 and 2.05, 260/230 ratios of 1.88 and 1.85, and no detectable DNA degradation by agarose gel electrophoresis. This protocol enabled whole-genome sequencing, yielding a 37.62 Mb assembly with 98.5% completeness as assessed by BUSCO v5 (basidiomycota_odb10 lineage dataset, n = 1,764). Liquid fermentation is associated with the production of younger, actively growing hyphae with reduced cell wall thickness, and the adapted CTAB method effectively removed residual polysaccharides. This protocol provides a reliable, cost-effective approach for obtaining sequencing-grade DNA from P. australis.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148944847","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":"The removal of iron and phosphate from culture medium by Rhodococcus ruber SiAl.","authors":"Galina Khokhlova, Konstantin Tikhonov, Olga Mironova, Tatiana Kulakovskaya, Mikhail Vainshtein","doi":"10.1007/s12223-026-01584-1","DOIUrl":"https://doi.org/10.1007/s12223-026-01584-1","url":null,"abstract":"<p><p>The microbial accumulation of heavy metals and phosphate is of interest for the bioremediation of polluted waters. In this work, we showed that at cultivation of the bacterium Rhodococcus ruber SiAl in the medium with 2.0 mM Fe³⁺ for stationary growth stage, up to 99% of the iron was associated with the biomass. Magnesium ion accumulation from the medium with 2 mM Mg²⁺ did not exceed 5% of the initial content. The cells did not remove manganese ions from the medium; moreover, the presence of MnSO₄ inhibited growth. The cells of Rhodococcus ruber SiAl removed phosphate from the medium: 75, 20, and 10% of the initial phosphate content was removed during cultivation in the presence of 6 mM phosphate and 2 mM Fe³⁺, 2 mM Mg²⁺, or 2 mM Mn²⁺, respectively. In the genome of R. ruber SiAl, genes encoding proteins of the siderophore synthesis systems and phosphate transport systems were identified. The strain was the most efficient for iron accumulation, which suggests a promising application for the removal of phosphate and iron from polluted waters.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148911471","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":"From lab to pilot scale: a low-cost fertilizer approach for astaxanthin production in Haematococcus pluvialis.","authors":"Zineb Mansouri, Imane Elfaidas, Ibtissam Lijassi, Laila Rhazi, Imane Wahby","doi":"10.1007/s12223-026-01586-z","DOIUrl":"https://doi.org/10.1007/s12223-026-01586-z","url":null,"abstract":"<p><p>Haematococcus pluvialis is one of the main commercially cultivated microalgae used for the production of natural astaxanthin. This potent antioxidant is naturally accumulated under stressful conditions, including high light intensity, nutrient deprivation, and osmotic stress. Nevertheless, high production costs, primarily associated with culture medium ingredients, remain a major bottleneck in industrial production. This study first evaluated carbon supplementation (NaHCO₃) and increased nitrogen (NaNO₃) concentrations to identify conditions that enhance biomass production, followed by the substitution of conventional N, P, K, and Mg sources with agricultural fertilizers to develop a cost-effective formulation for pilot-scale applications. The highest astaxanthin accumulation was achieved when 1.5 g/L carbon was added to the growth medium. Nitrogen supply had a lesser impact. Agricultural fertilizers, including ammonium nitrate (NH₄NO₃, 33.5% N), monoammonium phosphate (MAP, 12% N and 61% P₂O₅), phosphoric acid (PA, 86% H₃PO₄), potassium nitrate (KNO₃, 13.5% N and 46% K₂O), potassium sulfate (K₂SO₄, 51% K₂O), and magnesium sulfate (MgSO₄, 16% MgO), were subsequently used to replace conventional nutrient sources and develop low-cost formulations for outdoor cultivation. Among the tested formulations, F4, containing ammonium nitrate, potassium sulfate, and monoammonium phosphate, showed the best growth performance, reaching 9.85 × 10⁵ cells/mL and a biomass concentration of 3.15 g/L after 45 days, surpassing the carbon-supplemented and standard BBM conditions by 7% and 43%, respectively. When this formulation was used for pilot-scale cultivation, it maintained high performance during the green phase in closed photobioreactors and the red stage in open raceways, reaching a biomass concentration of 2.5 g/L and an astaxanthin yield of 350 mg/L after 45 days of cultivation. This formulation reduced medium-related biomass production costs by approximately 97.2-99.6% and offers a promising strategy for cost-effective, large-scale natural astaxanthin production.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148905484","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":"Unveiling the anticancer potential of genus Aerva as therapeutics for CLL (Chronic Lymphocytic Leukemia): from plant to patient.","authors":"Kinza Afzal, Nusrat Shafiq, Maryam Rashid, Shagufta Parveen","doi":"10.1007/s12223-026-01580-5","DOIUrl":"https://doi.org/10.1007/s12223-026-01580-5","url":null,"abstract":"<p><p>The genus Aervacomprises diverse medicinal plant species traditionally used for various therapeutic purposes, yet their pharmacokinetic and toxicological profiles remain largely uncharacterized. This study aimed to evaluate a library of 125 phytochemicals derived from Aerva species using comprehensive in silico approaches. Drug-likeness, ADME parameters, and toxicity profiles were assessed using SwissADME and ProTox-II platforms. Six compounds (AJ26, AJ30, AJ39, AJ43, AJ47, AJ55) exhibited optimal pharmacokinetic properties, including high gastrointestinal absorption, favorable lipophilicity (log P: 1.54-2.56), and acceptable water solubility. All selected compounds met multiple drug-likeness criteria and showed no PAINS alerts. Toxicity analysis revealed low risk for hepatotoxicity, carcinogenicity, and immunotoxicity. Three GEO datasets (GSE22529, GSE26725 and GSE50006) were examined to investigate their therapeutic relevance in chronic lymphocytic leukemia (CLL). 164 common differentially expressed genes (DEGs) were identified, which were primarily associated with pathways of B-cell activation and immunity. The protein-protein interaction analysis identified the CD22, CD38, and CCR6 as strong hub genes, with CD22 had the highest diagnostic performance (average AUC = 0.939). Molecular docking showed that all the molecules showed good interactions with the corresponding receptors such as AJ26-CD38, AJ30-CD22 and AJ43-CCR6. These findings show that Aerva-derived compounds as interesting candidates for future preclinical development in phytochemical-based therapeutics.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148886798","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 and phylogenetic analysis of Mannheimia haemolytica isolated from nasal samples of horses.","authors":"Derya Karataş Yeni, Yavuzkan Paksoy, Aslı Balevi, Fatih Büyük, Asma Ashraf, Beatriz Padron, Emine Eda Toslak","doi":"10.1007/s12223-026-01578-z","DOIUrl":"https://doi.org/10.1007/s12223-026-01578-z","url":null,"abstract":"<p><p>The Mannheimia genus, which is part of the upper respiratory tract microbiota, harbours species that have the potential to cause progressive infections, such as haemorrhagic septicaemia and enzootic pneumonia, when the host immune system is suppressed. Among these species, Mannheimia haemolytica is considered the most pathogenic, and horses can be a host for this agent. This study aimed to investigate the occurrence of Mannheimia haemolytica in horses with and without respiratory clinical signs and to assess the potential pathogenic significance of isolates recovered from animals through serotyping, detection of virulence-associated genes, and phylogenetic analysis. In this study, a total of 134 nasal swab samples were collected from horses reared in 15 farms in five provinces of Türkiye. Of these animals, 20 exhibited clinical signs of respiratory disease, while 114 were clinically healthy. All samples were analysed using cultural, phenotypic, and molecular methods for the detection of M. haemolytica. Ten (7.46%) isolates were identified as M. haemolytica by culture and subsequently confirmed by 16 S rDNA-PCR analysis. All M. haemolytica isolates were obtained exclusively from horses with clinical signs such as high fever, lethargy, loss of appetite, rhinorrhea, and coughing. Serotyping revealed that nine isolates belonged to Serotype 2 and one to Serotype 1. The leukotoxin (lkt) gene was detected in only one (11.11%) Serotype 2 isolate. Similarly, the Ssa-1 protein gene was detected in one Serotype 1 strain. One Serotype 2 isolate carrying the lktCABD operon clustered closely with leukotoxin-associated sequences of both M. haemolytica and M. glucosida, while remaining consistent with its independently established species identity. These findings indicate that M. haemolytica, including strains carrying virulence-associated markers, can be recovered from the upper respiratory tract of horses exhibiting respiratory disease. The exclusive recovery of M. haemolytica from clinically affected horses suggests a potential association with equine respiratory disease, although its causal role requires further investigation.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148886830","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}