MicrobiologyOpen最新文献

{"title":"A loophole in soap dispensers mediates contamination with Gram-negative bacteria","authors":"Ralf Lucassen,&nbsp;Nicole van Leuven,&nbsp;Dirk Bockmühl","doi":"10.1002/mbo3.1384","DOIUrl":"https://doi.org/10.1002/mbo3.1384","url":null,"abstract":"<p>Liquid soap dispensers are widely used in domestic and clinical settings. In previous studies, the risk of bacterial contamination of refillable systems was pointed out and a bacterial contamination rate of 25%, with values of up to 10⁸ colony-forming units/mL (CFU/mL), was reported. However, the route of contamination remains elusive. To address this point, we determined the microbial contamination of refillable standard pump dispensers and nonrefillable press-dispenser systems. Following the collection of 104 liquid soap dispensers from hotel rooms across Germany, bacterial counts were determined. Isolates of samples containing nonfastidious Gram-negative^(lac−) bacteria were further analyzed by the Vitek 2 system for the determination of species. 70.2% of the refillable pump dispensers (mean total bacterial count = 2.2 × 10⁵ CFU/mL) but only 10.6% of the nonrefillable press dispensers, were contaminated (mean total bacterial count = 1.5 × 10¹ CFU/mL). Of samples containing <i>nonfastidious Gram-negative</i>^(lac−) bacteria, <i>Pluralibacter gergoviae</i> was present in 41.7%, <i>Pseudomonads</i> (<i>Pseudomonas aeruginosa</i> and <i>Pseudomonas putida</i>) in 25%, <i>Serratia marcescens</i> in 16.7%, and <i>Klebsiella oxytoca</i> and <i>Pasteurella testudinis</i> in 8.3%. After the initial assessment, we contaminated different dispensing systems with <i>P. aeruginosa/P. gergoviae</i>, to reveal the route of contamination and identied the pressure release of standard pump dispensers as the loophole for microbial contamination.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"12 5","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.1384","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50147914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of light conditions on the production of chrysolaminarin using Phaeodactylum tricornutum in artificially illuminated photobioreactors","authors":"Konstantin Frick,&nbsp;Tobias Ebbing,&nbsp;Yen-Cheng Yeh,&nbsp;Ulrike Schmid-Staiger,&nbsp;Günter E. M. Tovar","doi":"10.1002/mbo3.1378","DOIUrl":"https://doi.org/10.1002/mbo3.1378","url":null,"abstract":"<p>The light conditions are of utmost importance in any microalgae production process especially involving artificial illumination. This also applies to a chrysolaminarin (soluble 1,3-β-glucan) production process using the diatom <i>Phaeodactylum tricornutum</i>. Here we examine the influence of the amount of light per gram biomass (specific light availability) and the influence of two different biomass densities (at the same amount of light per gram biomass) on the accumulation of the storage product chrysolaminarin during nitrogen depletion in artificially illuminated flat-panel airlift photobioreactors. Besides chrysolaminarin, other compounds (fucoxanthin, fatty acids used for energy storage [C16 fatty acids], and eicosapentaenoic acid) are regarded as well. Our results show that the time course of C-allocation between chrysolaminarin and fatty acids, serving as storage compounds, is influenced by specific light availability and cell concentration. Furthermore, our findings demonstrate that with increasing specific light availability, the maximal chrysolaminarin content increases. However, this effect is limited. Beyond a certain specific light availability (here: 5 µmol_photons g_DW⁻¹ s⁻¹) the maximal chrysolaminarin content no longer increases, but the rate of increase becomes faster. Furthermore, the conversion of light to chrysolaminarin is best at the beginning of nitrogen depletion. Additionally, our results show that a high biomass concentration has a negative effect on the maximal chrysolaminarin content, most likely due to the occurring self-shading effects.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"12 5","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.1378","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50152216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bacterial surface-exposed lipoproteins and sortase-mediated anchored cell surface proteins in plant infection","authors":"Andrés de Sandozequi,&nbsp;Claudia Martínez-Anaya","doi":"10.1002/mbo3.1382","DOIUrl":"https://doi.org/10.1002/mbo3.1382","url":null,"abstract":"<p>The bacterial cell envelope is involved in all stages of infection and the study of its components and structures is important to understand how bacteria interact with the extracellular milieu. Thanks to new techniques that focus on identifying bacterial surface proteins, we now better understand the specific components involved in host–pathogen interactions. In the fight against the deleterious effects of pathogenic bacteria, bacterial surface proteins (at the cell envelope) are important targets as they play crucial roles in the colonization and infection of host tissues. These surface proteins serve functions such as protection, secretion, biofilm formation, nutrient intake, metabolism, and virulence. Bacteria use different mechanisms to associate proteins to the cell surface via posttranslational modification, such as the addition of a lipid moiety to create lipoproteins and attachment to the peptidoglycan layer by sortases. In this review, we focus on these types of proteins (and provide examples of others) that are associated with the bacterial cell envelope by posttranslational modifications and their roles in plant infection.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"12 5","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.1382","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50133176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Orientia tsutsugamushi: A life between escapes","authors":"Lea Fromm,&nbsp;Jonas Mehl,&nbsp;Christian Keller","doi":"10.1002/mbo3.1380","DOIUrl":"https://doi.org/10.1002/mbo3.1380","url":null,"abstract":"<p>The life cycle of the mite-borne, obligate intracellular pathogen <i>Orientia tsutsugamushi</i> (<i>Ot</i>), the causative agent of human scrub typhus, differs in many aspects from that of other members of the Rickettsiales order. Particularly, the nonlytic cellular exit of individual <i>Ot</i> bacteria at the plasma membrane closely resembles the budding of enveloped viruses but has only been rudimentarily studied at the molecular level. This brief article is focused on the current state of knowledge of escape events in the life cycle of <i>Ot</i> and highlights differences in strategies of other rickettsiae.\u0000\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure></p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"12 5","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.1380","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50128103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rifampicin-resistant RpoB S522L Vibrio vulnificus exhibits disturbed stress response and hypervirulence traits","authors":"Laura Cutugno,&nbsp;Conor O'Byrne,&nbsp;Jan Pané-Farré,&nbsp;Aoife Boyd","doi":"10.1002/mbo3.1379","DOIUrl":"https://doi.org/10.1002/mbo3.1379","url":null,"abstract":"<p>Rifampicin resistance, which is genetically linked to mutations in the RNA polymerase β-subunit gene <i>rpoB</i>, has a global impact on bacterial transcription and cell physiology. Previously, we identified a substitution of serine 522 in RpoB (i.e., RpoB^S522L) conferring rifampicin resistance to <i>Vibrio vulnificus</i>, a human food-borne and wound-infecting pathogen associated with a high mortality rate. Transcriptional and physiological analysis of <i>V. vulnificus</i> expressing RpoB^S522L showed increased basal transcription of stress-related genes and global virulence regulators. Phenotypically these transcriptional changes manifest as disturbed osmo-stress responses and toxin-associated hypervirulence as shown by reduced hypoosmotic-stress resistance and enhanced cytotoxicity of the RpoB^S522L strain. These results suggest that RpoB-linked rifampicin resistance has a significant impact on <i>V. vulnificus</i> survival in the environment and during infection.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"12 5","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.1379","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50128104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating models and assessment techniques for understanding oral biofilm complexity","authors":"Srinivas Sulugodu Ramachandra,&nbsp;Patricia Wright,&nbsp;Pingping Han,&nbsp;Abdalla Abdal-hay,&nbsp;Ryan S. B. Lee,&nbsp;Saso Ivanovski","doi":"10.1002/mbo3.1377","DOIUrl":"10.1002/mbo3.1377","url":null,"abstract":"<p>Oral biofilms are three-dimensional (3D) complex entities initiating dental diseases and have been evaluated extensively in the scientific literature using several biofilm models and assessment techniques. The list of biofilm models and assessment techniques may overwhelm a novice biofilm researcher. This narrative review aims to summarize the existing literature on biofilm models and assessment techniques, providing additional information on selecting an appropriate model and corresponding assessment techniques, which may be useful as a guide to the beginner biofilm investigator and as a refresher to experienced researchers. The review addresses previously established 2D models, outlining their advantages and limitations based on the growth environment, availability of nutrients, and the number of bacterial species, while also exploring novel 3D biofilm models. The growth of biofilms on clinically relevant 3D models, particularly melt electrowritten fibrous scaffolds, is discussed with a specific focus that has not been previously reported. Relevant studies on validated oral microcosm models that have recently gaining prominence are summarized. The review analyses the advantages and limitations of biofilm assessment methods, including colony forming unit culture, crystal violet, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide inner salt assays, confocal microscopy, fluorescence in situ hybridization, scanning electron microscopy, quantitative polymerase chain reaction, and next-generation sequencing. The use of more complex models with advanced assessment methodologies, subject to the availability of equipment/facilities, may help in developing clinically relevant biofilms and answering appropriate research questions.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"12 4","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.1377","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10120492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transforming the untransformable with knockout minicircles: High-efficiency transformation and vector-free allelic exchange knockout in the fish pathogen Photobacterium damselae","authors":"Oleksandra Rudenko,&nbsp;Laura Baseggio,&nbsp;Fynn McGuigan,&nbsp;Andrew C. Barnes","doi":"10.1002/mbo3.1374","DOIUrl":"10.1002/mbo3.1374","url":null,"abstract":"<p>Gene inactivation studies are critical in pathogenic bacteria, where insights into species biology can guide the development of vaccines and treatments. Allelic exchange via homologous recombination is a generic method of targeted gene editing in bacteria. However, generally applicable protocols are lacking, and suboptimal approaches are often used for nonstandard but epidemiologically important species. <i>Photobacterium damselae</i> subsp. <i>piscicida</i> (<i>Pdp</i>) is a primary pathogen of fish in aquaculture and has been considered hard to transform since the mid-1990s. Consequently, conjugative transfer of RK2/RP4 suicide vectors from <i>Escherichia coli</i> S17-1/SM10 donor strains, a system prone to off-target mutagenesis, was used to deliver the allelic exchange DNA in previous studies. Here we have achieved efficient electrotransformation in <i>Pdp</i> using a salt-free highly concentrated sucrose solution, which performs as a hypertonic wash buffer, cryoprotectant, and electroporation buffer. High-efficiency transformation has enabled vector-free mutagenesis for which we have employed circular minimalistic constructs (knockout minicircles) containing only allelic exchange essentials that were generated by Gibson assembly. Preparation of competent cells using sucrose and electroporation/integration of minicircles had virtually no detectable off-target promutagenic effect. In contrast, a downstream <i>sacB</i> selection apparently induced several large deletions via mobilization of transposable elements. Electroporation of minicircles into sucrose-treated cells is a versatile broadly applicable approach that may facilitate allelic exchange in a wide range of microbial species. The method permitted inactivation of a primary virulence factor unique to <i>Pdp</i>, apoptogenic toxin AIP56, demonstrating the efficacy of minicircles for difficult KO targets located on the high copy number of small plasmids.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"12 4","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.1374","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10141159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antibiofilm assay for antimicrobial peptides combating the sulfate-reducing bacteria Desulfovibrio vulgaris","authors":"Lena Stillger,&nbsp;Lucile Viau,&nbsp;Dirk Holtmann,&nbsp;Daniela Müller","doi":"10.1002/mbo3.1376","DOIUrl":"10.1002/mbo3.1376","url":null,"abstract":"<p>In medical, environmental, and industrial processes, the accumulation of bacteria in biofilms can disrupt many processes. Antimicrobial peptides (AMPs) are receiving increasing attention in the development of new substances to avoid or reduce biofilm formation. There is a lack of parallel testing of the effect against biofilms in this area, as well as in the testing of other antibiofilm agents. In this paper, a high-throughput screening was developed for the analysis of the antibiofilm activity of AMPs, differentiated into inhibition and removal of a biofilm. The sulfate-reducing bacterium <i>Desulfovibrio vulgaris</i> was used as a model organism. <i>D. vulgaris</i> represents an undesirable bacterium, which is considered one of the major triggers of microbiologically influenced corrosion. The application of a 96-well plate and steel rivets as a growth surface realizes real-life conditions and at the same time establishes a flexible, simple, fast, and cost-effective assay. All peptides tested in this study demonstrated antibiofilm activity, although these peptides should be individually selected depending on the addressed aim. For biofilm inhibition, the peptide DASamP1 is the most suitable, with a sustained effect for up to 21 days. The preferred peptides for biofilm removal are S6L3-33, in regard to bacteria reduction, and Bactenecin, regarding total biomass reduction.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"12 4","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.1376","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10141160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cattle–compost–soil: The transfer of antibiotic resistance in livestock agriculture","authors":"Fadhel Abbas,&nbsp;Phil Thomas,&nbsp;Bianca Cully-Duse,&nbsp;Nicholas M. Andronicos,&nbsp;Gal Winter","doi":"10.1002/mbo3.1375","DOIUrl":"10.1002/mbo3.1375","url":null,"abstract":"<p>Antibiotic resistance is a major global health threat. Agricultural use of antibiotics is considered to be a main contributor to the issue, influencing both animals and humans as defined by the One Health approach. The purpose of the present study was to determine the abundance of antibiotic-resistant bacterial populations and the overall bacterial diversity of cattle farm soils that have been treated with animal manure compost. Soil and manure samples were collected from different sites at Tullimba farm, NSW. Cultures were grown from these samples in the presence of 11 commonly used antibiotics and antibiotic-resistant bacteria (ARB) colonies were identified. Soil and manure bacterial diversity was also determined using 16S ribosomal RNA next-generation sequencing. Results showed that ARB abundance was greatest in fresh manure and significantly lower in composted manure. However, the application of composted manure on paddock soil led to a significant increase in soil ARB abundance. Of the antibiotics tested, the number of ARB in each sample was greatest for antibiotics that inhibited the bacterial cell wall and protein synthesis. Collectively, these results suggest that the transfer of antibiotic resistance from composted animal manure to soil may not be solely mediated through the application of live bacteria and highlight the need for further research into the mechanism of antibiotic resistance transfer.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"12 4","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.1375","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10141161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation and characterization of filamentous fungi capable of degrading the mycotoxin patulin","authors":"Megumi Mita,&nbsp;Rina Sato,&nbsp;Miho Kakinuma,&nbsp;Hiroyuki Nakagawa,&nbsp;Toshiki Furuya","doi":"10.1002/mbo3.1373","DOIUrl":"10.1002/mbo3.1373","url":null,"abstract":"<p>Patulin is a toxic secondary metabolite synthesized by various fungal strains. This mycotoxin is generally toxic to microorganisms as well as mammals due to its reactivity with the important cellular antioxidant glutathione. In this study, we explored the presence of microorganisms capable of degrading patulin. Microorganisms were screened for the ability to both grow in culture medium containing patulin and reduce its concentration. Screening of 510 soil samples resulted in the isolation of two filamentous fungal strains, one of which, <i>Acremonium</i> sp. TUS-MM1 was characterized in detail. Liquid chromatography-mass spectrometry and nuclear magnetic resonance analyses revealed that TUS-MM1 cells degraded patulin to desoxypatulinic acid. In addition, extracellular components of strain TUS-MM1 also exhibited patulin-transforming activity. High-performance liquid chromatography analysis revealed that the extracellular components generated several products from patulin. Disc diffusion assay using <i>Escherichia coli</i> cells revealed that the patulin-transformation products by the extracellular components are less toxic than patulin. We also demonstrated that a thermostable, low-molecular-weight compound within the extracellular components was responsible for the patulin-transforming activity. These results suggest that strain TUS-MM1 transforms patulin into less-toxic molecules by secreting a highly reactive compound. In addition, once patulin enters the cells, strain TUS-MM1 can transform it into desoxypatulinic acid to reduce its toxicity.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"12 4","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.1373","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10141162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}