Folia microbiologica最新文献

{"title":"Novel Silviavirus phages with broad-host-range activity against methicillin resistant Staphylococcus aureus from seafood: comprehending the phenotypic and genotypic variability.","authors":"Karthika Raveendran, Sifana Sharaf, Ammu Lakshmi D, Reshmi K, Toms Cheriyath Joseph, Raja Swaminathan Thangaraj, Visnuvinayagam Sivam, Shashikanta Parida, Nagendra R Hegde, Ravindranath Shashidhar, Madhusudana Rao Badireddy, Vandan Nagar, Murugadas Vaiyapuri","doi":"10.1007/s12223-025-01290-4","DOIUrl":"https://doi.org/10.1007/s12223-025-01290-4","url":null,"abstract":"<p><p>Methicillin-resistant Staphylococcus aureus (MRSA) poses significant challenges to global health, attributed to their ability to resist multiple antibiotic classes. In the current situation, phage-based biocontrol strategies offer a promising alternative, leveraging their high specificity and efficacy against multidrug-resistant bacteria. The present study reports the phenotypic and genotypic characterizations of three broad-host-range MRSA phages: φCIFT_MFB_MRSA12, φCIFT_MFB_MRSA28, and φCIFT_MFB_MRSA32 for their application in seafood safety. The phages exhibited burst sizes ranging from 75 to 107 PFU/cell and burst periods of 80-90 min. The thermal and pH stability studies indicated that φCIFT_MFB_MRSA12 exhibited the highest thermal stability (- 20 to 60 °C), while φCIFT_MFB_MRSA28 demonstrated the widest pH tolerance (pH 3-12). The genomic analysis indicated that the phages possessed linear double-stranded DNA ranging from 141,193 to 141,505 bp, with large direct terminal repeats (DTRs) of 10,893 bp and various coding and non-coding genes (group-I introns, HEARO, and RAGATH). The comparative genome analysis revealed that three phages were found to be closely related to Silviavirus phages of the Herelleviridae family and differed with respect to tail fiber proteins, Ig domain-like carbohydrate-binding domains, and certain hypothetical proteins. Interestingly, the intergenomic and phylogenetic analyses revealed that the phages belonged to a novel species. Importantly, the genomes lacked virulence factors, antimicrobial resistance genes, or lysogenic determinants, supporting their safety in biocontrol strategies. The three Silviavirus phages could be potential candidates for the biocontrol of MRSA in seafood supply chains, thereby contributing to food safety and security.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144590805","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":"Expression of SAP1-3 genes in non-albicans Candida isolates in bovine raw milk and human sample.","authors":"Zahra Namvar, Abbas Akhavan Sepahy, Robab Rafiei Tabatabaei, Somayeh Sharifynia, Farzad Aala, Sassan Rezaie","doi":"10.1007/s12223-025-01284-2","DOIUrl":"https://doi.org/10.1007/s12223-025-01284-2","url":null,"abstract":"<p><p>Candida species are now taken as one of the essential opportunistic pathogens in clinical specimens. Although Candida albicans is one of the most essential opportunistic pathogens, non-albicans Candida (NAC) should not be taken for granted because these microorganisms are among the most common pathogens in patients today, leading to diseases, such as candidiasis, gastrointestinal tract infection, and vulvovaginitis. Fungal agents produce secreted aspartic proteinases (SAPs) to penetrate tissues. SAPs facilitate the invasion and colonization of host tissue by rupturing host mucosal membranes. They play an important role in weakening the structural and immunological defense proteins. The aim of this study was to compare the expression of SAP 1-3 genes in NAC isolated from different samples. We isolated the NAC such as Candida parapsilosis (C. parapsilosis), Candida tropicalis (C. tropicalis), Pichia kudriavzevii (P. kudriavzevii), and Nakaseomyces glabrata (N. glabrata) from two different sources of bovine raw milk and human samples. Then, we compared the expression of SAP1, SAP2, and SAP3 genes in both samples by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). The results of gene expression showed that expression of the genes SAP2 and SAP3 was different in C. parapsilosis detected from raw milk and human samples. The expression of SAP2 was significantly decreased in human samples (**p < 0.01), whereas the expression of SAP3 was significantly increased in human samples (*p < 0.05). In some cases, the expression of these genes was similar among N. glabrata, P. kudriavzevii, and C. tropicalis. The expression of SAP2 and SAP3 genes in the same species of NAC from various sources is different.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144575183","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":"Integrative genome analysis of bacteriocin-producing Lactiplantibacillus pentosus LNP1-39 and its synbiotic role in suppressing food-borne pathogens.","authors":"Thanadol Jirakanjanasit, Natladda Choovet, Auttaporn Booncharoen, Engkarat Kingkaew, Saranporn Poothong, Somboon Tanasupawat, Sukanya Phuengjayaem","doi":"10.1007/s12223-025-01285-1","DOIUrl":"https://doi.org/10.1007/s12223-025-01285-1","url":null,"abstract":"<p><p>Lactic acid bacteria were isolated from traditional Thai-fermented foods. Among these, the strain LNP1-39, closely related to Lactiplantibacillus pentosus, was selected for further study because of its non-pathogenic profile. The bacteriocins produced by L. pentosus LNP1-39 were proteinaceous substances that exhibited strong antimicrobial activity across a wide pH range (pH 2-11; 6400-2400 AU/mL) and thermal stability at 100 °C for 40 min (400 AU/mL). These bacteriocins showed a narrow antimicrobial spectrum, effectively targeting Gram-positive pathogens, such as Kocuria rhizophila MIII, Enterococcus faecalis JCM 5803^T, and Listeria monocytogenes ATCC 19115. Comprehensive safety assessments, including whole-genome analysis and in vitro tests, confirmed a low risk of antibiotic resistance and the absence of virulence factors. Strain LNP1-39 was confirmed to be closely related to L. pentosus DSM 20314^T via digital DNA‒DNA hybridization (dDDH; 75.4%), with average nucleotide identity (ANI) at 96.56% ANIb and 97.22% ANIm values. Additionally, LNP1-39 produces pediocin with notable similarity (76.29% identity to pediocin) and presents low risks for antibiotic-resistance genes or transfer genes while providing antioxidant properties. Strain LNP1-39 survived harsh gastrointestinal tract conditions and exhibited a favorable prebiotic index and positive prebiotic activity score when paired with polydextrose or isomalto-oligosaccharide. These findings support L. pentosus LNP1-39 as potential bacteriocin-producing lactic acid bacteria for further application in food preservation and pathogen control or as a synbiotic.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144575184","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":"Disruption of SAP1 confers vanillin tolerance in Saccharomyces cerevisiae.","authors":"Bora Kim","doi":"10.1007/s12223-025-01294-0","DOIUrl":"https://doi.org/10.1007/s12223-025-01294-0","url":null,"abstract":"<p><p>The objectives of this study were to identify genes associated with vanillin tolerance and to elucidate the link between vanillin tolerance and oxidative stress and the hog1 pathway activation in the yeast Saccharomyces cerevisiae for the production of biofuels and renewable chemicals from lignocellulosic biomass. In this study, one strain tolerant to vanillin stress was isolated through a transposon-mediated mutant library, and the disrupted gene was identified as SAP1. In addition, this phenotype associated with vanillin tolerance was confirmed by deletion and overexpressing of this corresponding gene. In response to vanillin stress, mutant strain was found to reduce intracellular level of reactive oxygen species (ROS), induce activation of Hog1p, and increase expression of the stress-response transcription factors MSN2/4 and genes mediated by stress response elements such as CTT1, HSP12, and DDR2.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144583508","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":"Purification and characterization of β-galactosidase from Aspergillus niger PQ570689 for lactose hydrolysis and prebiotic synthesis.","authors":"Abdullahi Dabban Idris, Moses Enemaduku Abalaka, Oluwafemi Adebayo Oyewole, Evans Chidi Egwim, Naga Raju Maddela","doi":"10.1007/s12223-025-01293-1","DOIUrl":"https://doi.org/10.1007/s12223-025-01293-1","url":null,"abstract":"<p><p>β-Galactosidase converts lactose to galactose and glucose, and it is significant for lactose-intolerant people. A Nigerian local strain of Aspergillus niger (accession number PQ570689) previously isolated from fermented goat milk in Minna, Niger State, Nigeria, was used to produce β-galactosidase. Diammonium sulfate precipitation and gel filtration were used to purify the crude enzyme. The impacts of temperature (10, 20, 30, 40, and 50 °C), pH (4, 5, 6, 7, and 8), metal ions (Fe, Mn, Cu, and Mg), chemical activators/inhibitors (SDS and Tween-80), sugars (fructose, glucose, and sucrose), and substrate concentrations (o-nitrofenyl-beta-D-galaktopyranoside (ONPG)) on the purified enzyme activity were determined. The kinetic parameters including Vmax (maximum velocity) and Km (Michaelis-Menten constant) of the partially purified enzyme were also estimated. Afterwards, lactose hydrolysis and prebiotic production potential of the purified beta-galactosidase was evaluated using high-performance liquid chromatography (HPLC). The purified enzyme was characterized by the highest enzyme activity (338 U/mL), specific activity (18.82 U/mL per mg), and fold purification (35.78), as well as the least protein content (18 mg/mL). The purified β-galactosidase was most active at pH 7 and 50 °C. The enzyme was, however, inhibited by all the metal ions, surfactants, and sugars tested. This biocatalyst was characterized by a substantial catalytic capability (Vmax = 666.67 U/mL per min) and moderate affinity (Km = 8.67 mmol) to its substrate. The purified enzyme showed a great potential for lactose hydrolysis (> 99%) as well as a good prospect for prebiotics synthesis (7%). Thus, the β-galactosidase can be developed for various industrial, environmental, and biotechnological applications.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144564731","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":"Biofilm formation efficiency by Candida species isolated from gastric mucosa of intragastric balloon patient under extremely low pH.","authors":"Andressa Prado, Flávia Franco Veiga, Rubens de Oliveira Brito, Elton da Cruz Alves Pereira, Melyssa Negri, Terezinha Inez Estivalet Svidzinski","doi":"10.1007/s12223-025-01286-0","DOIUrl":"https://doi.org/10.1007/s12223-025-01286-0","url":null,"abstract":"<p><p>This study characterized biofilms formed by Candida albicans and C. tropicalis isolated from the gastric mucosa biopsies of an intragastric balloon (IGB) patient user. Both were cultivated to form single and mixed artificial biofilms at pH 2.5 and 5.5 for 24 and 48 h. The biofilms were assessed for biochemical, metabolic, and ultrastructural properties. Yeast counts in monospecies C. albicans and C. tropicalis biofilms were higher than their respective levels in mixed biofilms across both pH values. Single C. tropicalis biofilms exhibited greater metabolic activity at both time points than C. albicans and mixed biofilms. While there were no notable pH or time-dependent differences in C. albicans and C. tropicalis monospecies biofilm formation, mixed biofilms displayed significantly higher biomass at pH 2.5. Ct also demonstrated pronounced filamentation within 24 h at pH 5.5. Scanning electron microscopy revealed cellular damage in mixed biofilms at pH 2.5; although, the biofilm structure was well developed within 24-48 h. Our findings indicate that yeasts isolated from IGB patients can form mono and polymicrobial biofilms under harsh conditions, with both species demonstrating biofilm viability at pH 2.5. Notably, C. tropicalis exhibited increased competitiveness in mixed biofilms under these conditions.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144552811","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":"Constitutive ALS3 expression in Candida albicans has differential effects on yeast-locked tet-NRG1 and brg1Δ strains.","authors":"Nicholas C Schena, Kassandra M Baker, Anna A Stark, Derek P Thomas, Ian A Cleary","doi":"10.1007/s12223-025-01288-y","DOIUrl":"https://doi.org/10.1007/s12223-025-01288-y","url":null,"abstract":"<p><p>The fungal pathogen Candida albicans produces numerous surface proteins involved in adhesion. Many of these adhesins are specific to different morphological forms. Strains that are unable to form hyphae are generally impaired in their ability to adhere to surfaces and to form biofilms. To better understand the function of one of these adhesins, Als3p, in the context of yeast-locked strains, we expressed ALS3 in strains with altered expression of one of two genes that are part of a regulatory circuit, BRG1 and NRG1. The mutant BRG1 and NRG1 strains we examined were phenotypically similar. We observed that ALS3 expression improved the adhesion of both strains to glass but that only one had altered biofilm forming ability, which was decreased.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144539713","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":"Application of a superpixel-based segmentation method to root micrographs for total fungal colonization rate estimation.","authors":"Laurie Paulin, Didier Techer","doi":"10.1007/s12223-025-01292-2","DOIUrl":"https://doi.org/10.1007/s12223-025-01292-2","url":null,"abstract":"<p><p>This work illustrates a novel application of a supervised superpixel-based segmentation method for root micrograph classification and total fungal colonization rate estimation. Two procedures relying on successive classifier application on different root micrographs or on the same micrograph but with an increasing number of labels to be assigned to each picture element category are compared to a reference grid-intersect count method. Finally, supervised classification with at least 16 labels on the same picture appears as a convenient method for obtaining rapid and confident colonization rate estimates. We suggest this kind of method may be easily and routinely implemented for research or educational purposes.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144539712","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 resistance mechanisms in non-tuberculous mycobacteria.","authors":"Esra Gül Tursun, Taylan Bozok, Gönül Aslan","doi":"10.1007/s12223-025-01287-z","DOIUrl":"https://doi.org/10.1007/s12223-025-01287-z","url":null,"abstract":"<p><p>Non-tuberculous mycobacteria (NTM) are pathogens that are widely distributed in the environment and cause increasing rates of human infections. High levels of antimicrobial resistance shown by these bacteria complicate infection management and limit treatment options. The complex structure of cell walls and features such as biofilm formation are responsible for intrinsic resistance in NTMs. Antimicrobial resistance can be explained by four basic mechanisms: (i) limitation of drug uptake, meaning antibiotic entry is limited due to the presence of a hydrophobic and low permeability cell wall and a small number of porin channels, (ii) enzymatic modification of antibiotics, (iii) target site modification, (iv) efflux pumps, which prevent drug accumulation by actively expelling antibiotics from the cell and reduce treatment efficacy. For effective management of NTM infections, detailed understanding of resistance mechanisms, development of species-specific treatment protocols, and discovery of new antimicrobial agents are of great importance. In this review, the mechanisms causing drug resistance in NTMs will be reviewed.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144527125","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":"Evaluation of andrographolide from Andrographis paniculata against drug-resistant and H₃₇Rv strains of Mycobacterium tuberculosis.","authors":"Jelin Vilvest, M C John Milton, Alex Yagoo, Kedike Balakrishna","doi":"10.1007/s12223-025-01291-3","DOIUrl":"https://doi.org/10.1007/s12223-025-01291-3","url":null,"abstract":"<p><p>Tuberculosis (TB) remains a major global health concern, particularly due to the emergence of multidrug-resistant (MDR) Mycobacterium tuberculosis strains. While previous studies have suggested andrographolide as a potential antimycobacterial agent based on in silico predictions, limited empirical evidence exists on its direct efficacy against MDR-TB. This study systematically evaluates the antimycobacterial activity of andrographolide through the microbroth dilution method against M. tuberculosis H₃₇Rv and three distinct MDR strains. The minimum inhibitory concentrations (MICs) were determined using Middlebrook 7H9 medium, with rifampicin and isoniazid as positive controls. Andrographolide completely inhibited M. tuberculosis H₃₇Rv at an MIC of 125 µg/mL, while MICs for MDR strains varied (500 µg/mL, 125 µg/mL, and 250 µg/mL for MDR-Isolates 1, 2, and 3, respectively). Unlike previous studies that primarily relied on computational docking models, our findings provide direct experimental validation of andrographolide's strain-specific efficacy, demonstrating its potential as a promising lead compound for anti-tubercular drug development. These results underscore the need for further preclinical investigations to explore its therapeutic applications in combating drug-resistant TB.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144527126","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}