BMC Microbiology最新文献

{"title":"In vitro antibacterial and antibiofilm activities of isobavachalcone against Enterococcus faecalis clinical isolates from China.","authors":"Lili Ouyang, Zhicao Xu, Yuanyuan Tang, Duoyun Li, Zhijian Yu, Zewen Wen, Haigang Zhang, Chaoqin Zhang","doi":"10.1186/s12866-025-03836-5","DOIUrl":"10.1186/s12866-025-03836-5","url":null,"abstract":"<p><strong>Background: </strong>The pharmacological activities of the natural product isobavachalcone, such as antimicrobial activity, reverse transcriptase blockade, and antioxidant property have been extensively reported. Whereas, its antimicrobial and biofilm-inhibitory effects on clinical E. faecalis strains in China, along with its potential mechanisms, are still not fully clear. This research is intended to assess the in vitro antibacterial and anti-biofilm effects of isobavachalcone against clinical E. faecalis isolates sourced from China. Moreover, it further explores the potential target site of it within E. faecalis.</p><p><strong>Results: </strong>It was found that the minimum inhibitory concentrations (MICs) of isobavachalcone ranged from 6.25 to 12.5 µM against 220 E. faecalis clinical strains obtained from a tertiary hospital in China. The antibiofilm activity of it with sub-MIC concentration ( 1/2 × MIC ) against the biofilm formation of E. faecalis was demonstrated and Time -killing curve assay revealed the quick bactericidal effect of isobavachalcone against E. faecalis planktonic cells. However, no synergetic bactericidal activity of isobavachalcone co-administered with vancomycin, or ampicillin was observed for eradicating the biofilm. Moreover, isobavachalcone-resistant E. faecalis was isolated by in vitro induction of isobavachalcone, and whole genome sequencing was performed to determine the genetic mutations of ten functional proteins in isobavachalcone-resistant E. faecalis, including PurH and FlgJ, with the other eight proteins being related to cell wall or cell membrane biogenesis, DNA synthesis, and energy metabolism. In addition, molecular docking results indicate that there is a potential binding of isobavachalcone and PurH protein in E. faecalis.</p><p><strong>Conclusion: </strong>This research highlights the potential of isobavachalcone as a potent antibacterial agent against E. faecalis clinical isolates, capable of significantly inhibiting biofilm formation at sub-MIC concentrations. PurH protein in E. faecalis might serve as a potential target of isobavachalcone and the specific action mechanism of isobavachalcone needs further study.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"105"},"PeriodicalIF":4.0,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11869651/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143531146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitrogen metabolism of the highly ureolytic bacterium Proteus penneri S99 isolated from the rumen.","authors":"Sijia Liu, Nan Zheng, Jiaqi Wang, Shengguo Zhao","doi":"10.1186/s12866-025-03808-9","DOIUrl":"10.1186/s12866-025-03808-9","url":null,"abstract":"<p><strong>Background: </strong>The model rumen-dominant ureolytic bacterium P. penneri S99 exhibits high urease activity. It was cultivated using ammonia, urea, amino acids, or their combination as nitrogen sources. To identify differences in gene expression, the transcript abundances of various genes involved in nitrogen metabolism were analyzed by harvesting mRNA from cells during the exponential growth phases on different nitrogen sources.</p><p><strong>Results: </strong>P. penneri S99 can utilize ammonia, urea, or amino acids as the sole nitrogen sources for growth and shows a preference for utilizing urea. It exhibits similar growth rates and maximum biomass on ammonia and urea, but showed higher growth rates and maximum biomass on amino acids. Transcriptome sequencing analysis revealed different transcription patterns in response to different nitrogen sources. The urease gene expression was detected in all three different nitrogen sources, and complete hydrolysis of urea was also observed when other nitrogen sources were added to the medium containing urea. The regulation of urease in P. penneri S99 was characterized by constitutive expression, not by urea. The growth of P. penneri S99 on ammonia, ammonium acid, and urea was similar, with the only observed difference being an increase in urease transcript abundance.</p><p><strong>Conclusions: </strong>The transcription patterns of nitrogen metabolism genes offer insights into how nitrogen is utilized in the rumen.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"104"},"PeriodicalIF":4.0,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11869435/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143531147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genomic analysis of Brucella melitensis isolates recovered from humans in south Tunisia over 35 years between 1988 and 2022.","authors":"Boutheina Ksibi, Fahmi Smaoui, Nourelhouda Ben Ayed, Manel Guetat, Senda Mezghani, Sonia Ktari, Faouzia Mahjoubi, Mounir Ben Jemaa, Héla Karray, Adnene Hammami","doi":"10.1186/s12866-025-03802-1","DOIUrl":"10.1186/s12866-025-03802-1","url":null,"abstract":"<p><p>Brucella melitensis is a zoonotic pathogen that poses a worldwide public health challenge. In recent years, whole-genome sequencing has become a widely accepted molecular typing method for the genomic epidemiology of brucellosis. This study reports the genomic characteristics of 24 B. melitensis strains isolated from human infections in southern Tunisia over 35 years (1988-2022). We utilized WGS to analyze the clonal relationships of these strains, their relatedness to international sequences, their antimicrobial resistance determinants, and their virulence factors. Our findings revealed a high genetic stability over three decades. All isolates were identified as B. melitensis biovar 3 and were assigned to the same sequence type, ST11, using the MLST-9 scheme. Using the MLST-21, Tunisian sequences shared 20 out of 21 alleles and were assigned to 2 closely related STs (ST89 and ST114). Phylogenetic analysis indicated that all Tunisian sequences were grouped into a single subcluster within lineage I, the West Mediterranean clade, and were highly related to other strains from the Maghreb region (Morocco and Algeria). Antimicrobial resistance analysis revealed no classical resistance determinants. However, mprF, bepCDEFG genes, and missense mutations in rpoB, gyrA, gyrB, and parC genes were identified. Virulence analysis identified 67 genes, predominantly involved in lipopolysaccharide biosynthesis and the type IV secretion system. To our knowledge, this study represents the first genomic investigation of B. melitensis strains circulating in Tunisia. Our findings underscore the importance of genomic surveillance in understanding the epidemiology and evolution of brucellosis in North Africa.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"98"},"PeriodicalIF":4.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11866833/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143514654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From soil to surface water: exploring Klebsiella 's clonal lineages and antibiotic resistance odyssey in environmental health.","authors":"Sara Araújo, Vanessa Silva, Micaela Quintelas, Ângela Martins, Gilberto Igrejas, Patricia Poeta","doi":"10.1186/s12866-025-03798-8","DOIUrl":"10.1186/s12866-025-03798-8","url":null,"abstract":"<p><p>In the last decade, the presence of resistant bacteria and resistance genes in the environment has been a cause for increasing concern. However, understanding of its contribution to the spread of bacteria remains limited, as the scarcity of studies on how and under what circumstances the environment facilitates the development of resistance poses challenges in mitigating the emergence and spread of mobile resistance factors. Antimicrobial resistance in the environment is considered one of the biggest challenges and threats currently emerging. Thus, monitoring the presence of antibiotic-resistant species, in this particular case, Klebsiella spp., in the environment can be an added value for understanding the epidemiology of infections caused by Klebsiella spp.. Investigating soils and waters as potential reservoirs and transmission vehicles for these bacteria is imperative. Therefore, in this review, we aimed to describe the main genetic lineages present in environmental samples, as well as to describe the multidrug resistance strains associated with each environmental source. The studies analyzed in this review reported a high diversity of species and strains of Klebsiella spp. in the environment. K. pneumoniae was the most prevalent species, both in soil and water samples, and, as expected, often presented a multi-resistant profile. The presence of K. pneumoniae ST11, ST15, and ST147 suggests human and animal origin. Concerning surface waters, there was a great diversity of species and STs of Klebsiella spp. These studies are crucial for assessing the environmental contribution to the spread of pathogenic bacteria.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"97"},"PeriodicalIF":4.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11866855/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143514649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Therapeutic Efficacy of MS473, a Fully Human Single-Chain Variable Fragment Targeting Staphylococcus aureus Toxic Shock Syndrome Toxin-1, in a D-Galactosamine-Sensitized Mouse Model of Lethal Shock.","authors":"Fatemeh Rahimi-Jamnani, Hamid Reza Moradi, Abolfazl Fateh, Masoumeh Azizi, Farzaneh Nazari, Mahdieh Soezi, Seyed Davar Siadat","doi":"10.1186/s12866-025-03825-8","DOIUrl":"10.1186/s12866-025-03825-8","url":null,"abstract":"<p><p>Toxic shock syndrome toxin-1 (TSST-1), produced by Staphylococcus aureus, is one of the most potent superantigens involved in causing life-threatening TSS and contributes to the onset of some autoimmune diseases. To this end, we have previously identified a fully human single-chain variable fragment antibody (scFv), MS473, exhibiting high binding affinity and specificity for TSST-1 and demonstrating in vitro neutralization activity. In the present study, the therapeutic activity of MS473 was assessed in a D-galactosamine-sensitized mouse model of lethal shock. D-galactosamine-sensitized mice were injected with TSST-1 and then received a single dose of MS473 intraperitoneally (15 mg per kg of mouse body weight) after five minutes or intravenously (3 mg per kg of mouse body weight) after 10 min. The survival rate was examined for seven days. Furthermore, blood samples from different groups of mice were subjected to biochemical assessment, and their kidneys and livers were analyzed histopathologically 24 h after the toxin injection. The findings demonstrated a 100% survival rate with no significant damage to kidney and liver function in the treated groups, receiving MS473 through two different administration routes compared to the control groups, including the toxin-injected mice receiving normal saline or an unrelated scFv. Targeting disseminated TSST-1 with the scFv, which has appropriate permeability and distribution throughout the body, may be an effective way to alleviate the malfunctioning of the immune system caused by TSST-1.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"95"},"PeriodicalIF":4.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11863401/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143514581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diversity of endophytic bacteria in Paris Polyphylla var. yunnanensis and their correlation with polyphyllin content.","authors":"Qing Shu, Liping Ruan, Yuying Wu, Lin Jin, Jing Wang, Anzhong Peng, Haifeng Li, Siman Gu","doi":"10.1186/s12866-025-03814-x","DOIUrl":"10.1186/s12866-025-03814-x","url":null,"abstract":"<p><strong>Background: </strong>Paris polyphylla var. yunnanensis (PPY) is commonly used in traditional Chinese medicine formulas and folk families. Nearly more than 100 chemical substances with medicinal values have been reported in PPY, among which steroidal saponins are the main active components. Due to its long growth cycle, the resource of PPY has become too scarce, and the current production capacity of PPY is still far from meeting the market demand. Numerous studies have shown that endophytic bacteria not only promote the production of secondary metabolites in the host plant, but some of them are also able to produce the same secondary metabolites as the host. However, little is known about the endophytic bacteria associated with PPY in different geographic conditions and tissues. In order to compare the endophytic bacterial communities associated with PPY in different geographic conditions and plant tissues, the endophytic bacteria from roots, stems, and leaves of PPY collected from five locations were isolated, and the diversity, richness, and homogeneity of bacterial communities were analyzed, and the dominant genera correlation with polyphyllin content was further investigated.</p><p><strong>Results: </strong>A total of 268 endophytic bacterial strains were isolated and identified from PPY. The experimental results showed that the isolates belonged to 5 phyla, 7 classes, 14 orders and 39 genera of bacteria, of which the dominant order was Bacillariophyta and the dominant genera were Bacillus, Pseudomonas and Agrobacterium. In general, the differences in the distribution pattern and diversity of endophytic bacteria in PPY were characterized by the highest diversity and richness index of endophytic bacterial communities in Er yuan Qisheng (QS) and the highest evenness index in Dali Fengyi (FY). The diversity, richness and evenness of bacterial communities in terms of tissue state showed a hierarchical pattern of root > stem > leaf. The three optimal genera were positively correlated with polyphyllin content.</p><p><strong>Conclusion: </strong>The distribution pattern and diversity of endophytic bacteria in PPY were influenced by tissue type and habitat. In addition, three endophytic bacteria (Pseudomonas, Bacllius and Agrobacterium) were positively correlated with the content of polyphylin.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"93"},"PeriodicalIF":4.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11863604/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143514664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the BadR regulon in Borrelia burgdorferi.","authors":"Sierra George, Zhiming Ouyang","doi":"10.1186/s12866-025-03797-9","DOIUrl":"10.1186/s12866-025-03797-9","url":null,"abstract":"<p><strong>Background: </strong>Borrelia burgdorferi, the causative agent of Lyme disease, relies on tightly coordinated gene expression to quickly adapt and survive in the tick vector and mammalian host. BadR, an ROK (repressor, open reading frame, kinase) family transcriptional regulator, binds directly to B. burgdorferi promoter DNA, however, many questions concerning the role for BadR in gene regulation remain unanswered. In particular, there are conflicting reports concerning what genes are regulated by BadR in B. burgdorferi. Furthermore, previous studies have suggested important roles for BadR in unfed ticks, but the BadR regulon has not been defined under such conditions. Additionally, although BadR regulates rpoS expression in a growth phase-dependent manner, it remains unknown whether BadR regulates other genes during different growth phases.</p><p><strong>Results: </strong>To address these questions, we cultivated a B. burgdorferi badR mutant and wild-type strain under various conditions and analyzed the transcriptome using RNA-sequencing. When spirochetes were grown at 37 °C and collected at the mid-logarithmic and stationary phase of growth, 211 and 272 genes were differentially expressed in the badR mutant, respectively. A total of 79 genes were differentially expressed when spirochetes were grown at 23 °C. A vast majority of genes identified in this study encode proteins of unknown function.</p><p><strong>Conclusions: </strong>Complex transcriptional regulation mechanisms coordinate the expression of genes required for the survival of B. burgdorferi throughout its tick-mammal enzootic lifecycle. As part of this process, BadR functions as a global regulatory protein and regulates B. burgdorferi virulence gene expression. Combined, this work supports a role for BadR in global B. burgdorferi gene regulation by modulating expression of different sets of genes at different stages of the enzootic lifecycle. We anticipate that investigating the function of genes in the BadR regulon will lead to the identification of novel virulence factors for therapeutic and vaccine development.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"94"},"PeriodicalIF":4.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11863449/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143514718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights into diversity, host-range, and temporal stability of Bacteroides and Phocaeicola prophages.","authors":"Nejc Stopnisek, Stina Hedžet, Tomaž Accetto, Maja Rupnik","doi":"10.1186/s12866-025-03827-6","DOIUrl":"10.1186/s12866-025-03827-6","url":null,"abstract":"<p><strong>Background: </strong>Phages are critical components of the gut microbiome, influencing bacterial composition and function as predators, parasites, and modulators of bacterial phenotypes. Prophages, integrated forms of these phages, are prevalent in many bacterial genomes and play a role in bacterial adaptation and evolution. However, the diversity and stability of prophages within gut commensals, particularly in the genera Bacteroides and Phocaeicola, remain underexplored. This study aims to screen and characterize prophages in these genera, providing insights into their diversity, host range, and temporal dynamics in the human gut.</p><p><strong>Results: </strong>Using a combination of three bioinformatic tools-Cenote-Taker 3, Vibrant, and PHASTER-we conducted a comprehensive analysis of prophages in Bacteroides and Phocaeicola. Cenote-Taker 3 identified the most diverse set of prophages, with significant overlaps observed between the tools. After clustering high-quality prophages, we identified 22 unique viral operational taxonomic units (vOTUs). Notably, comparisons between prophages identified in isolated bacterial genomes, metaviromes, and large public gut virome databases revealed a broader host range than initially observed in single isolates. Certain prophages were consistent across time points and individuals, suggesting temporal stability. All identified prophages belonged to the Caudoviricetes class and contained genes related to antibiotic resistance, toxin production, and metabolic processes.</p><p><strong>Conclusions: </strong>The combined use of multiple prophage detection tools allowed for a more comprehensive assessment of prophage diversity in Bacteroides and Phocaeicola. The identified prophages were not only prevalent but also exhibited broad host ranges and temporal stability. The presence of antibiotic resistance and toxin genes suggests that these prophages may significantly influence bacterial community structure and function in the gut, with potential implications for human health. These findings highlight the importance of using diverse detection tools to accurately assess prophage diversity and dynamics.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"92"},"PeriodicalIF":4.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11863486/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143514670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization and genome analysis of novel Klebsiella pneumoniae phage vbKpUKJ_2 isolated from hospital sewage water.","authors":"Kamran Ahmad Mirza, Tinatini Tchatchiashvili, Mike Marquet, Sandor Nietzsche, Mathias W Pletz, Oliwia Makarewicz","doi":"10.1186/s12866-025-03813-y","DOIUrl":"10.1186/s12866-025-03813-y","url":null,"abstract":"<p><strong>Introduction: </strong>Multidrug-resistant (MDR) Klebsiella pneumoniae is a critical healthcare challenge due to its extensive resistance to antibiotics and role in causing severe infections. Bacteriophages offer a promising alternative for targeting MDR pathogens. This study characterizes a novel phage, vbKpUKJ_2, isolated from hospital sewage water, against clinical K. pneumoniae isolates.</p><p><strong>Methods: </strong>Phage vbKpUKJ_2 was isolated and purified using the double agar overlay method. Host range and sensitivity were tested against 40 clinical K. pneumoniae isolates using growth inhibition assays. Morphological characterization was performed using transmission electron microscopy (TEM). Genomic analysis was conducted to evaluate the absence of antibiotic resistance genes and determine phylogenetic relationships. Stability assays assessed the phage's thermal and pH tolerance.</p><p><strong>Results: </strong>Phage vbKpUKJ_2 demonstrated broad range activity against clinical K. pneumoniae isolates. TEM revealed it belongs to the Drexlerviridae family. Genomic analysis confirmed the absence of antibiotic resistance genes and identified conserved functional regions shared with related phages. vbKpUKJ_2 exhibited broad pH stability (pH 4-10) and thermal stability between 30 °C and 60 °C. The one-step growth curve indicated rapid lytic activity, with a burst size of 323 phage particles per cell.</p><p><strong>Conclusion: </strong>vbKpUKJ_2 shows promising therapeutic potential against MDR K. pneumoniae. Its stability, absence of resistance genes, and rapid lytic cycle highlight its suitability for inclusion in phage therapy protocols, particularly as part of combination therapies targeting MDR infections.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"96"},"PeriodicalIF":4.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11863478/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143514476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphologic changes in the model tintinnid Schmidingerella (Alveolata, Ciliophora) during the cell cycle, including the first volumetric analyses of the lorica-forming material.","authors":"Sabine Agatha, Birgit Weißenbacher, Laura Böll, Maximilian H Ganser","doi":"10.1186/s12866-025-03780-4","DOIUrl":"10.1186/s12866-025-03780-4","url":null,"abstract":"<p><strong>Background: </strong>Tintinnids are marine planktonic ciliates with tube-shaped or vase-shaped loricae (shells). During the cell cycle, lorica-forming material (LFM) is generated and accumulates in the proter (anterior division product). After transverse fission, the proter leaves the lorica and subsequently secretes the material, creating its own shell, while the opisthe (posterior division product) retains the parental one. The timing of material production and its final quantity are unknown.</p><p><strong>Results: </strong>Our study focussed on Schmidingerella Agatha & Strüder-Kypke, 2012, a model tintinnid genus with transparent, champagne flute-shaped loricae. Protargol-stained field material from the Chesapeake Bay on the Northwest Atlantic provided detailed insights into the morphologic changes, including the LFM production, during the cell cycle. We defined five division stages based on features of the opisthe's newly forming membranellar zone (oral primordium) recognisable both in live and fixed material. The start of LFM production in middle dividers and its intracellular distribution matched the findings obtained from monoclonal, methyl blue-eosin-stained culture material from the Northeast Pacific, in which the LFM was volumetrically analysed. Just before fission, the LFM occupied on average 6.7% of the cell volume. The wall volume of the finished lorica estimated by a shape function was at least 4.5-fold larger than the volume of the intracellular material.</p><p><strong>Conclusions: </strong>The LFM is generated only during a certain period of the cell cycle, i.e., in early middle to late dividers. The difference in volume between the initially secreted LFM and the finished lorica wall suggests that significant structural changes take place in the material during lorica formation.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"88"},"PeriodicalIF":4.0,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11853588/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143499254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}