Research in microbiology最新文献

{"title":"Alleviating the virulence of Pseudomonas aeruginosa and Staphylococcus aureus by ascorbic acid nanoemulsion","authors":"Farag M. Mosallam ,&nbsp;Hisham A. Abbas ,&nbsp;Ghada H. Shaker ,&nbsp;Salwa E. Gomaa","doi":"10.1016/j.resmic.2023.104084","DOIUrl":"10.1016/j.resmic.2023.104084","url":null,"abstract":"<div><p><span><span>The high incidence of persistent multidrug resistant bacterial infections is a worldwide public health burden. Alternative strategies are required to deal with such issue including the use of drugs with anti-virulence activity. The application of nanotechnology to develop advanced Nano-materials that target quorum sensing regulated </span>virulence factors<span> is an attractive approach. Synthesis of ascorbic acid Nano-emulsion (ASC-NEs) and assessment of its activity </span></span><em>in vitro</em> against the virulence factors and its protective ability against pathogenesis as well as the effect against expression of quorum sensing genes of <span><em>Pseudomonas aeruginosa</em></span> and <span><em>Staphylococcus aureus</em></span><span><span> isolates. Ascorbic acid Nano-emulsion was characterized by DLS Zetasizer Technique, Zeta potential<span>; Transmission Electron Microscopy (TEM) and </span></span>Fourier transform infrared spectroscopy<span><span> (FT-IR). The antibacterial activity of ASC-NEs was tested by the </span>broth microdilution method and the activity of their sub-MIC against the expression of quorum sensing controlled virulence was investigated using phenotypic experiments and RT-PCR. The protective activity of ASC-NEs against </span></span><em>P. aeruginosa</em> as well as <em>S. aureus</em> pathogenesis was tested <em>in vivo</em>. Phenotypically, ASC-NEs had strong virulence inhibitory activity against the tested bacteria. The RT-PCR experiment showed that it exhibited significant QS inhibitory activity. The <em>in vivo</em> results showed that ASC-NEs protected against staphylococcal infection, however, it failed to protect mice against Pseudomonal infection. These results suggest the promising use of nanoformulations against virulence factors in multidrug resistant <em>P. aeruginosa</em> and <em>S. aureus</em>. However, further studies are required concerning the potential toxicity, clearance and phamacokinetics of the nanoformulations.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"174 7","pages":"Article 104084"},"PeriodicalIF":2.6,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10270898","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":"Archaea: current and potential biotechnological applications","authors":"David Aparici-Carratalá,&nbsp;Julia Esclapez,&nbsp;Vanesa Bautista,&nbsp;María-José Bonete,&nbsp;Mónica Camacho","doi":"10.1016/j.resmic.2023.104080","DOIUrl":"10.1016/j.resmic.2023.104080","url":null,"abstract":"<div><p>Archaea are microorganisms with great ability to colonize some of the most inhospitable environments in nature, managing to survive in places with extreme characteristics for most microorganisms. Its proteins and enzymes are stable and can act under extreme conditions in which other proteins and enzymes would degrade. These attributes make them ideal candidates for use in a wide range of biotechnological applications. This review describes the most important applications, both current and potential, that archaea present in Biotechnology, classifying them according to the sector to which the application is directed. It also analyzes the advantages and disadvantages of its use.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"174 7","pages":"Article 104080"},"PeriodicalIF":2.6,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10259019","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":"Bacteriophages potentiate the effect of antibiotics by eradication of persister cells and killing of biofilm-forming cells","authors":"Javiera Vera-Mansilla ,&nbsp;Cecilia A. Silva-Valenzuela ,&nbsp;Patricio Sánchez ,&nbsp;Roberto C. Molina-Quiroz","doi":"10.1016/j.resmic.2023.104083","DOIUrl":"10.1016/j.resmic.2023.104083","url":null,"abstract":"<div><p>Persister cells and biofilms are associated with chronic urinary infections which are more critical when generated by multi-drug resistant bacteria. In this context, joint administration of phages and antibiotics has been proposed as an alternative approach, since it may decrease the probability to generate resistant mutants to both agents. In this work, we exposed cultures of uropathogenic <em>Escherichia coli</em> conjunctly to antibiotics and phages. We determined that MLP2 combined with antibiotics eradicates persister cells. Similarly, MLP1 and MLP3 impact viability of biofilm-forming cells when administered with ampicillin. Our findings suggest a feasible prophylactic and therapeutic use of these non-transducing phages.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"174 7","pages":"Article 104083"},"PeriodicalIF":2.6,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10278484","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 AcrAB efflux pump confers self-resistance to stilbenes in Photorhabdus laumondii","authors":"Linda Hadchity ,&nbsp;Jessica Houard ,&nbsp;Anne Lanois ,&nbsp;Amaury Payelleville ,&nbsp;Fida Nassar ,&nbsp;Maxime Gualtieri ,&nbsp;Alain Givaudan ,&nbsp;Ziad Abi Khattar","doi":"10.1016/j.resmic.2023.104081","DOIUrl":"10.1016/j.resmic.2023.104081","url":null,"abstract":"<div><p><span>The Resistance-nodulation-division (RND)-type AcrAB-TolC efflux pump contributes to multidrug resistance in Gram-negative bacteria. Recently, the bacterium </span><span><em>Photorhabdus</em><em> laumondii</em></span> TT01 has emerged as a goldmine for novel anti-infective drug discovery. Outside plants, <em>Photorhabdus</em><span> is the only Gram-negative known to produce stilbene-derivatives including 3,5-dihydroxy-4-ethyl-trans-stilbene and 3,5-dihydroxy-4-isopropyl-trans-stilbene (IPS). IPS is a bioactive polyketide which received considerable attention, mainly because of its antimicrobial properties, and is currently in late-stage clinical development as a topical treatment for psoriasis and dermatitis. To date, little is known about how </span><em>Photorhabdus</em> survives in the presence of stilbenes. We combined genetic and biochemical approaches to assess whether AcrAB efflux pump exports stilbenes in <em>P. laumondii</em>. We demonstrated that the wild-type (WT) exerts an antagonistic activity against its derivative Δ<em>acrA</em> mutant, and that is able to outcompete it in a dual-strain co-culture assay. The Δ<em>acrA</em> mutant also showed high sensitivity to 3,5-dihydroxy-4-ethyl-trans-stilbene and IPS as well as decreased IPS concentrations in its supernatant comparing to the WT. We report here a mechanism of self-resistance against stilbene derivatives of <em>P. laumondii</em> TT01, which enables these bacteria to survive under high concentrations of stilbenes by extruding them out via the AcrAB efflux pump.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"174 7","pages":"Article 104081"},"PeriodicalIF":2.6,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10319878","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":"Myxobacteria: biology and bioactive secondary metabolites","authors":"Sandeep Kaur Saggu ,&nbsp;Amar Nath ,&nbsp;Shiv Kumar","doi":"10.1016/j.resmic.2023.104079","DOIUrl":"10.1016/j.resmic.2023.104079","url":null,"abstract":"<div><p>Myxobacteria<span> are Gram-negative eubacteria and they thrive in a variety of habitats including soil rich in organic matter, rotting wood, animal dung and marine environment. Myxobacteria are a promising source of new compounds associated with diverse bioactive spectrum and unique mode of action. The genome information of myxobacteria has revealed many orphan biosynthetic pathways indicating that these bacteria can be the source of several novel natural products. In this review, we highlight the biology of myxobacteria with emphasis on their habitat, life cycle, isolation methods and enlist all the bioactive secondary metabolites purified till date and their mode of action.</span></p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"174 7","pages":"Article 104079"},"PeriodicalIF":2.6,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10256388","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":"Evolution of YacG to safeguard DNA gyrase from external perturbation","authors":"Priti Biswas ,&nbsp;Sugopa Sengupta ,&nbsp;Valakunja Nagaraja","doi":"10.1016/j.resmic.2023.104093","DOIUrl":"10.1016/j.resmic.2023.104093","url":null,"abstract":"<div><p>Cells have evolved strategies to safeguard their genome integrity. We describe a mechanism to counter double strand breaks in the chromosome that involves the protection of an essential housekeeping enzyme from external agents. YacG is a DNA gyrase inhibitory protein from <em>Escherichia coli</em><span> that protects the bacterium from the cytotoxic effects of catalytic inhibitors as well as cleavage-complex stabilizers of DNA gyrase. By virtue of blocking the primary DNA binding<span><span> site of the enzyme, YacG prevents the accumulation of double strand breaks induced by gyrase poisons. It also enables the bacterium to resist the growth-inhibitory property of novobiocin. Gyrase poison-induced oxidative stress upregulates YacG production, probably as a cellular response to counter DNA damage. YacG-mediated protection of the genome is specific for gyrase targeting agents as the protection is not observed from the action of general DNA damaging agents. YacG also intensifies the transcription stress induced by rifampicin substantiating the importance of gyrase activity during transcription. Although essential for </span>bacterial survival, DNA gyrase often gets entrapped by external inhibitors and poisons, resulting in cell death. The existence of YacG to specifically protect an essential housekeeping enzyme might be a strategy adopted by bacteria for competitive fitness advantage.</span></span></p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"174 7","pages":"Article 104093"},"PeriodicalIF":2.6,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10319890","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":"Transcription factor mce3R modulates antibiotics and disease persistence in Mycobacterium tuberculosis","authors":"Manitosh Pandey ,&nbsp;Sakshi Talwar ,&nbsp;Rahul Pal ,&nbsp;Vaibhav Nain ,&nbsp;Sonia Johri ,&nbsp;Amit Singhal ,&nbsp;Amit Kumar Pandey","doi":"10.1016/j.resmic.2023.104082","DOIUrl":"10.1016/j.resmic.2023.104082","url":null,"abstract":"<div><p>Transcription factors (TFs) of <span><em>Mycobacterium tuberculosis</em></span><span> (Mtb), an etiological agent of tuberculosis, regulate a network of pathways that help prolong the survival of Mtb inside the host. In this study, we have characterized a transcription repressor gene (</span><em>mce3R</em><span>) from the TetR family, that encodes for Mce3R protein in </span><em>Mtb</em>. We demonstrated that the <em>mce3R</em> gene is dispensable for the growth of <em>Mtb</em> on cholesterol. Gene expression analysis suggests that the transcription of genes belonging to the <em>mce3R</em><span> regulon is independent of the carbon source. We found that, in comparison to the wild type, the </span><em>mce3R</em> deleted strain (<em>Δmce3R)</em><span> generated more intracellular ROS and demonstrated reduced susceptibility to oxidative stress. Total lipid analysis suggests that </span><em>mce3R</em> regulon encoded proteins modulate the biosynthesis of cell wall lipids in <em>Mtb</em>. Interestingly, the absence of Mce3R increased the frequency of generation of antibiotic persisters in <em>Mtb</em> and imparted <em>in-vivo</em> growth advantage phenotype in guinea pigs. In conclusion, genes belonging to the <em>mce3R</em> regulon modulate the frequency of generation of persisters in <em>Mtb</em>. Hence, targeting <em>mce3R</em> regulon encoded proteins could potentiate the current regimen by eliminating persisters during <em>Mtb</em> infection.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"174 7","pages":"Article 104082"},"PeriodicalIF":2.6,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10269858","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":"Key amino acids residues enhance the ability of CpcR to activate cry gene expression in Bacillus thuringiensis","authors":"Ruibin Zhang ,&nbsp;Yang Luo ,&nbsp;Lili Gang ,&nbsp;Yanrong Xu ,&nbsp;Xin Zhang ,&nbsp;Qi Peng ,&nbsp;Leyla Slamti ,&nbsp;Didier Lereclus ,&nbsp;Guirong Wang ,&nbsp;Fuping Song","doi":"10.1016/j.resmic.2023.104051","DOIUrl":"10.1016/j.resmic.2023.104051","url":null,"abstract":"<div><p>Typical <span><em>Bacillus thuringiensis</em></span><span> (Bt) produces one or more parasporal crystals composed of insecticidal Cry proteins during the sporulation<span>, and the parasporal crystals and spores are produced from the same cell. Strain Bt LM1212 is different from typical Bt strains in that its crystals and spores are produced in different cells. Previous studies have found that the cell differentiation process of Bt LM1212 is related to the transcription factor CpcR which activates the </span></span><em>cry</em>-gene promoters. In addition, CpcR could activate the Bt LM1212 <em>cry35-like</em> gene promoter (P_<em>35</em>) when introduced in the heterologous HD73^- strain. It was shown that P_<em>35</em> was only activated in non-sporulating cells. In this study, the peptidic sequences of CpcR homologous proteins found in other strains of the <span><em>Bacillus cereus</em></span> group were used as references to identify two key amino acid sites for CpcR activity. The function of these amino acids was investigated by measuring P_<em>35</em> activation by CpcR in strain HD73^-<span>. These results will lay a foundation for the optimization of the insecticidal protein expression system in non-sporulating cells.</span></p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"174 6","pages":"Article 104051"},"PeriodicalIF":2.6,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10119045","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":"l-tyrosine modulates biofilm formation of Bacillus cereus ATCC 14579","authors":"Linda Huijboom ,&nbsp;Marcel Tempelaars ,&nbsp;Mingzhen Fan ,&nbsp;Yourong Zhu ,&nbsp;Sjef Boeren ,&nbsp;Erik van der Linden ,&nbsp;Tjakko Abee","doi":"10.1016/j.resmic.2023.104072","DOIUrl":"10.1016/j.resmic.2023.104072","url":null,"abstract":"<div><p><em>Bacillus cereus</em> is a food-borne pathogen capable of producing biofilms. Following analysis of biofilm formation by <em>B. cereus</em> ATCC 14579 transposon mutants in defined medium (DM), a deletion mutant of <em>bc2939</em> (Δ<em>bc2939</em>) was constructed that showed decreased crystal violet biofilm staining and biofilm cell counts. In addition, Δ<em>bc2939</em> also produced smaller colony biofilms with lower cell counts and loss of wrinkly morphology. The <em>bc2939</em> gene encodes for Prephenate dehydrogenase, which converts Prephenate to 4-Hydroxy-phenylpyruvate (4-HPPA) in the <span>l</span>-tyrosine branch of the Shikimate pathway. While growth of the mutant and WT in DM was similar, addition of <span>l</span>-tyrosine was required to restore WT-like (colony) biofilm formation. Comparative proteomics showed reduced expression of Tyrosine-protein kinase/phosphatase regulators and extracellular polysaccharide cluster 1 (EPS1) proteins, aerobic electron transfer chain cytochrome <em>aa</em>3/d quinol oxidases, and iso-chorismate synthase involved in menaquinone synthesis in DM grown mutant biofilm cells, while multiple oxidative stress-related catalases and superoxide dismutases were upregulated. Performance in shaking cultures showed a 100-fold lower concentration of menaquinone-7 and reduction in cell counts of DM grown Δ<em>bc2939</em> indicating increased oxygen sensitivity. Combining all results, points to an important role of Tyrosine-modulated EPS1 production and menaquinone-dependent aerobic respiration in <em>B</em>. cereus ATCC 14579 (colony) biofilm formation.</p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"174 6","pages":"Article 104072"},"PeriodicalIF":2.6,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10053628","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 persistence of time: the lifespan of Bacillus anthracis spores in environmental reservoirs","authors":"Zoë R. Barandongo ,&nbsp;Amélie C. Dolfi ,&nbsp;Spencer A. Bruce ,&nbsp;Kristyna Rysava ,&nbsp;Yen-Hua Huang ,&nbsp;Hendrina Joel ,&nbsp;Ayesha Hassim ,&nbsp;Pauline L. Kamath ,&nbsp;Henriette van Heerden ,&nbsp;Wendy C. Turner","doi":"10.1016/j.resmic.2023.104029","DOIUrl":"10.1016/j.resmic.2023.104029","url":null,"abstract":"<div><p><span>Anthrax is a lethal bacterial zoonosis primarily affecting herbivorous wildlife and livestock. Upon host death </span><span><em>Bacillus anthracis</em></span><span><span> vegetative cells form spores capable of surviving for years in soil. Anthrax transmission requires host exposure to large spore doses. Thus, conditions that facilitate higher spore concentrations or promote spore survival will increase the probability that a pathogen reservoir infects future hosts. We investigated abiotic and pathogen genomic variation in relation to spore concentrations in surface soils (0–1 cm depth) at 40 </span>plains zebra </span><em>(Equus quagga)</em><span> anthrax carcass<span> sites in Namibia. Specifically, how initial spore concentrations and spore survival were affected by seasonality associated with the timing of host mortality, local soil characteristics, and pathogen genomic variation. Zebras dying of anthrax in wet seasons—the peak season for anthrax in Etosha National Park—had soil spore concentrations 1.36 orders of magnitude higher than those that died in dry seasons. No other variables considered affected spore concentrations, and spore survival rates did not differ among sites. Surface soils at these pathogen reservoirs remained culture positive for a range of 3.8–10.4 years after host death. Future research could evaluate if seasonal patterns in spore concentrations are driven by differences in sporulation success or levels of terminal bacteremia.</span></span></p></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"174 6","pages":"Article 104029"},"PeriodicalIF":2.6,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10060223","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}