Abstract:
:The gram-negative bacterium Francisella tularensis (Ft) is both a potential biological weapon and a naturally occurring microbe that survives in arthropods, fresh water amoeba, and mammals with distinct phenotypes in various environments. Previously, we used a number of measurements to characterize Ft grown in Brain-Heart Infusion (BHI) broth as (1) more similar to infection-derived bacteria, and (2) slightly more virulent in naïve animals, compared to Ft grown in Mueller Hinton Broth (MHB). In these studies we observed that the free amino acids in MHB repress expression of select Ft virulence factors by an unknown mechanism. Here, we tested the hypotheses that Ft grown in BHI (BHI-Ft) accurately displays a full protein composition more similar to that reported for infection-derived Ft and that this similarity would make BHI-Ft more susceptible to pre-existing, vaccine-induced immunity than MHB-Ft. We performed comprehensive proteomic analysis of Ft grown in MHB, BHI, and BHI supplemented with casamino acids (BCA) and compared our findings to published "omics" data derived from Ft grown in vivo. Based on the abundance of ~1,000 proteins, the fingerprint of BHI-Ft is one of nutrient-deprived bacteria that-through induction of a stringent-starvation-like response-have induced the FevR regulon for expression of the bacterium's virulence factors, immuno-dominant antigens, and surface-carbohydrate synthases. To test the notion that increased abundance of dominant antigens expressed by BHI-Ft would render these bacteria more susceptible to pre-existing, vaccine-induced immunity, we employed a battery of LVS-vaccination and S4-challenge protocols using MHB- and BHI-grown Ft S4. Contrary to our hypothesis, these experiments reveal that LVS-immunization provides a barrier to infection that is significantly more effective against an MHB-S4 challenge than a BHI-S4 challenge. The differences in apparent virulence to immunized mice are profoundly greater than those observed with primary infection of naïve mice. Our findings suggest that tularemia vaccination studies should be critically evaluated in regard to the growth conditions of the challenge agent.
journal_name
Front Microbioljournal_title
Frontiers in microbiologyauthors
Holland KM,Rosa SJ,Kristjansdottir K,Wolfgeher D,Franz BJ,Zarrella TM,Kumar S,Sunagar R,Singh A,Bakshi CS,Namjoshi P,Barry EM,Sellati TJ,Kron SJ,Gosselin EJ,Reed DS,Hazlett KROdoi
10.3389/fmicb.2017.01158subject
Has Abstractpub_date
2017-06-22 00:00:00pages
1158issn
1664-302Xjournal_volume
8pub_type
杂志文章abstract::Extended-spectrum β-lactamase (ESBL) producing Klebsiella pneumoniae pose an important threat of infection with increased morbidity and mortality, especially for immunocompromised patients. Here, we use the rise of multidrug-resistant K. pneumoniae in a German neurorehabilitation center from April 2015 to April 2016 t...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.00322
更新日期:2018-02-23 00:00:00
abstract::Two large-scale outbreaks of streptococcal toxic shock-like syndrome (STSLS) have revealed Streptococcus suis 2 to be a severe and evolving human pathogen. We investigated the mechanism by which S. suis 2 causes STSLS. The transcript abundance of the transcriptional regulator gene tstS was found to be upregulated duri...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.01309
更新日期:2018-06-19 00:00:00
abstract::Mycotic infections and their effect on the human condition have been widely overlooked and poorly surveilled by many health organizations even though mortality rates have increased in recent years. The increased usage of immunosuppressive and myeloablative therapies for the treatment of malignant as well as non-malign...
journal_title:Frontiers in microbiology
pub_type: 杂志文章,评审
doi:10.3389/fmicb.2016.00272
更新日期:2016-03-03 00:00:00
abstract::Metacaspases are distant homologs of metazoan caspase proteases, implicated in stress response, and programmed cell death (PCD) in bacteria and phytoplankton. While the few previous studies on metacaspases have relied on cultured organisms and sequenced genomes, no studies have focused on metacaspases in a natural set...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2016.01043
更新日期:2016-07-06 00:00:00
abstract::Despite numerous studies on marine prokaryotes, the vertical distribution patterns of bacterial community, either on the taxonomic composition or the functional structure, remains relatively unexplored. Using HiSeq-derived 16S rRNA data, the depth-related distribution patterns of taxonomic diversity and functional str...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.01730
更新日期:2020-09-10 00:00:00
abstract::Based on the Stable Ecotype Model, evolution leads to the divergence of ecologically distinct populations (e.g., with different niches and/or behaviors) of ecologically interchangeable membership. In this study, pyrosequencing was used to provide deep sequence coverage of Synechococcus psaA genes and transcripts over ...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2015.00590
更新日期:2015-06-22 00:00:00
abstract::The diversity of fungi in grape must and during wine fermentation was investigated in this study by culture-dependent and culture-independent techniques. Carignan and Grenache grapes were harvested from three vineyards in the Priorat region (Spain) in 2012, and nine samples were selected from the grape must after crus...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2015.01156
更新日期:2015-10-23 00:00:00
abstract::Recent findings provide evidence that fungal structures can be detected in brain tissue from Alzheimer's disease (AD) patients using rabbit polyclonal antibodies raised against whole fungal cells. In the present work, we have developed and tested specific antibodies that recognize the fungal proteins, enolase and β-tu...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2016.01772
更新日期:2016-11-07 00:00:00
abstract::Microorganisms play a crucial role in biogeochemical cycles and ecosystem processes, but the key factors driving microbial community structure are poorly understood, particularly in alpine environments. In this study, we aim to disentangle the relative contribution of abiotic and biotic factors shaping bacterial and f...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.00925
更新日期:2020-05-25 00:00:00
abstract::The alarming spread of bacterial resistance to traditional antibiotics has warranted the study of alternative antimicrobial agents. Quorum sensing (QS) is a chemical cell-to-cell communication mechanism utilized by bacteria to coordinate group behaviors and establish infections. QS is integral to bacterial survival, a...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2015.00189
更新日期:2015-03-10 00:00:00
abstract::Strain 212 of Penicillium rubens (PO212) is an effective fungal biological control agent against a broad spectrum of diseases of horticultural plants. A pyrimidine auxotrophic isolate of PO212, PO212_18.2, carrying an inactive pyrG gene, has been used as host for transformation by positive selection of vectors contain...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.01653
更新日期:2018-07-23 00:00:00
abstract::Many bacteria belonging to the phylum of Actinobacteria are known as antagonists against phytpathogenic microbes. This study aimed to analyze the effect of ozone on the actinobacterial community of the rhizosphere of four years old European beech (Fagus sylvatica L.) trees during different time points of the vegetatio...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2014.00036
更新日期:2014-02-11 00:00:00
abstract::Currently, sulfate-reducing bacteria (SRB) is regarded as the main culprit of microbiologically influenced corrosion (MIC), mainly due to the low reported corrosion rates of other microorganisms. For example, the highest reported corrosion rate for methanogens is 0.065 mm/yr. However, by investigating methanogen-induc...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.00527
更新日期:2020-03-31 00:00:00
abstract::Azole-resistant (azole-R) Aspergillus is an increasing challenge worldwide. Patients with cystic fibrosis (CF) are at risk of Aspergillus colonization and disease due to a favorable lung environment for microorganisms. We performed a nationwide study in 2018 of azole-non-susceptible Aspergillus in CF patients and comp...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.01850
更新日期:2020-08-13 00:00:00
abstract::The dearth of new antibiotics in the face of widespread antimicrobial resistance makes developing innovative strategies for discovering new antibiotics critical for the future management of infectious disease. Understanding the genetics and evolution of antibiotic producers will help guide the discovery and bioenginee...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2016.00573
更新日期:2016-05-03 00:00:00
abstract::Listeria monocytogenes is a serious foodborne pathogen that can contaminate food during processing and can grow during food shelf-life. New types of safe and effective food contact materials embedding antimicrobial agents, like silver, can play an important role in the food industry. The present work aimed at evaluati...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2016.00307
更新日期:2016-03-07 00:00:00
abstract::The biocontrol fungus Trichoderma longibrachiatum SMF2 secretes a large quantity of peptaibols that have been shown to have a range of biological activities and therefore great application values. However, the mechanism of the regulatory expression of peptaibols is still unclear. The putative methyltransferase LaeA/LA...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.01267
更新日期:2020-06-12 00:00:00
abstract::During cystic fibrosis (CF) chronic lung infections, bacteria of the Burkholderia cepacia complex (Bcc) are exposed for several years to a stressful and changing environment. These environmental challenges results in genetic changes of the initial infecting strain with the consequent diversification of genotypes and p...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2016.02024
更新日期:2016-12-20 00:00:00
abstract::New fungal SMs (SMs) have been successfully described to be produced by means of in vitro-simulated microbial community interactions. Co-culturing of fungi has proved to be an efficient way to induce cell-cell interactions that can promote the activation of cryptic pathways, frequently silent when the strains are grow...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2017.00649
更新日期:2017-04-19 00:00:00
abstract::Molasses are sub-products of the sugar industry, rich in sucrose and containing other sugars like raffinose, glucose, and fructose. Alpha-galactosidases (EC. 3.2.1.22) catalyze the hydrolysis of alpha-(1,6) bonds of galactose residues in galacto-oligosaccharides (melibiose, raffinose, and stachyose) and complex galact...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2019.00405
更新日期:2019-03-07 00:00:00
abstract::The vertebrate gut teems with a large, diverse, and dynamic bacterial community that has pervasive effects on gut physiology, metabolism, and immunity. Under natural conditions, these microbes share their habitat with a similarly dynamic community of eukaryotes (helminths, protozoa, and fungi), many of which are well-...
journal_title:Frontiers in microbiology
pub_type: 杂志文章,评审
doi:10.3389/fmicb.2018.00843
更新日期:2018-05-14 00:00:00
abstract::Inducer of meiosis 2 (Ime2), a protein kinase that has been identified in diverse fungal species, functions in the regulation of various cellular processes, such as ascospore formation, pseudohyphal growth, and sexual reproduction. In this study, AoIme2, an ortholog of Saccharomyces cerevisiae Ime2, was characterized ...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2019.03065
更新日期:2020-01-14 00:00:00
abstract::Disturbance in gut microbiota is crucial for the development of Clostridioides difficile infection (CDI). Different mechanisms through which gut microbiota influences C. difficile colonization are known. However, C. difficile could also affect gut microbiota balance as previously demonstrated by cultivation of fecal m...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.01633
更新日期:2018-07-24 00:00:00
abstract::Experimental manipulation of the intestinal microbiota influences health of the host and is a common application for synbiotics. Here Clostridium butyricum (C. butyricum, C.B) combined with corn bran (C.B + Bran) was taken as the synbiotics application in a waned pig model to investigate its regulation of intestinal h...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.03091
更新日期:2018-12-18 00:00:00
abstract::Random transposon mutagenesis is a powerful technique used to generate libraries of genetic insertions in many different bacterial strains. Here we develop a system facilitating random transposon mutagenesis in a range of different Gram-negative bacterial strains, including Pectobacterium atrosepticum, Citrobacter rod...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2015.01442
更新日期:2015-12-22 00:00:00
abstract::Recent studies of bacterial speciation have claimed to support the biological species concept-that reduced recombination is required for bacterial populations to diverge into species. This conclusion has been reached from the discovery that ecologically distinct clades show lower rates of recombination than that which...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2015.01540
更新日期:2016-01-14 00:00:00
abstract::The intestinal microbiome is essential in humans to maintain physiological balance and nutrition metabolism. Laparoscopic cholecystectomy due to gallstone disease and cholecystitis can cause intestinal microbial dysbiosis, and following bile acid metabolism dysfunction, positions the patient at high risk of colorectal...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.01402
更新日期:2018-06-25 00:00:00
abstract::The eastern China marginal seas (ECMS) are prominent examples of river-dominated ocean margins, whose most characteristic feature is the existence of isolated mud patches on sandy sediments. Ammonia-oxidizing prokaryotes play a crucial role in the nitrogen cycles of many marine environments, including marginal seas. H...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2016.00137
更新日期:2016-02-12 00:00:00
abstract::At different stages throughout their life cycle, plants often encounter several pathogenic microbes that challenge plant growth and development. The sophisticated innate plant immune system prevents the growth of harmful microbes via two interconnected defense strategies based on pathogen perception. These strategies ...
journal_title:Frontiers in microbiology
pub_type: 杂志文章,评审
doi:10.3389/fmicb.2020.01298
更新日期:2020-07-03 00:00:00
abstract::Many Gram-negative bacteria use a type VI secretion system (T6SS) for microbial warfare and/or host manipulation. Acinetobacter baumannii is an important nosocomial pathogen and many A. baumannii strains utilize a T6SS to deliver toxic effector proteins to surrounding bacterial cells. These toxic effectors are usually...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2019.02440
更新日期:2019-10-30 00:00:00