Abstract:
:Fluoroquinolone resistance can cause major clinical problems. Here, we investigated fluoroquinolone resistance mechanisms in a clinical Escherichia coli isolate, HUE1, which had no mutations quinolone resistance-determining regions (QRDRs) of DNA gyrase and topoisomerase IV. HUE1 demonstrated MICs that exceeded the breakpoints for ciprofloxacin, levofloxacin, and norfloxacin. HUE1 harbored oqxAB and qnrS1 on distinct plasmids. In addition, it exhibited lower intracellular ciprofloxacin concentrations and higher mRNA expression levels of efflux pumps and their global activators than did reference strains. The genes encoding AcrR (local AcrAB repressor) and MarR (MarA repressor) were disrupted by insertion of the transposon IS3-IS629 and a frameshift mutation, respectively. A series of mutants derived from HUE1 were obtained by plasmid curing and gene knockout using homologous recombination. Compared to the MICs of the parent strain HUE1, the fluoroquinolone MICs of these mutants indicated that qnrS1, oqxAB, acrAB, acrF, acrD, mdtK, mdfA, and tolC contributed to the reduced susceptibility to fluoroquinolone in HUE1. Therefore, fluoroquinolone resistance in HUE1 is caused by concomitant acquisition of QnrS1 and OqxAB and overexpression of AcrAB-TolC and other chromosome-encoded efflux pumps. Thus, we have demonstrated that QRDR mutations are not absolutely necessary for acquiring fluoroquinolone resistance in E. coli.
journal_name
Front Microbioljournal_title
Frontiers in microbiologyauthors
Sato T,Yokota S,Uchida I,Okubo T,Usui M,Kusumoto M,Akiba M,Fujii N,Tamura Ydoi
10.3389/fmicb.2013.00125subject
Has Abstractpub_date
2013-05-24 00:00:00pages
125issn
1664-302Xjournal_volume
4pub_type
杂志文章abstract::Temperature is the main factor to control the microbial growth in perishable foods. The psychrotrophic pathogen bacteria are microorganisms of concern for food products with extended shelf life in chilling conditions. The aims of this work were two. Firstly, to evaluate growth behavior of Aeromonas hydrophila DSM-3018...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.03023
更新日期:2018-12-05 00:00:00
abstract::In this study, we investigated the pattern of antimicrobial resistance in Salmonella enterica serotype Enteritidis isolates in Shanghai, China from 2005 to 2014. We found the first isolates with resistance to the fourth-generation cephalosporin cefepime starting in 2010. Furthermore, we analyzed the epidemic character...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.00910
更新日期:2020-05-15 00:00:00
abstract::Sea star wasting (SSW) disease describes a condition affecting asteroids that resulted in significant Northeastern Pacific population decline following a mass mortality event in 2013. The etiology of SSW is unresolved. We hypothesized that SSW is a sequela of microbial organic matter remineralization near respiratory ...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.610009
更新日期:2021-01-06 00:00:00
abstract::A novel carbapenem-hydrolyzing beta-lactamase, called IMP-63, was identified in three clonally distinct strains of Pseudomonas aeruginosa and two strains of Pseudomonas putida isolated within a 4 year timeframe in three French hospitals. The blaIMP-63 gene that encodes this carbapenemase turned out to be located in th...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2019.00404
更新日期:2019-03-04 00:00:00
abstract::Filamentous fungi asymptomatically colonize the inner tissues of macroalgae, yet their ecological roles remain largely underexplored. Here, we tested if metabolites produced by fungal endophytes might protect their host against a phylogenetically broad spectrum of protistan pathogens. Accordingly, the cultivable funga...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.03161
更新日期:2018-12-21 00:00:00
abstract::Heat resistance of microorganisms can be affected by different influencing factors. Although, the effect of heating rates has been scarcely explored by the scientific community, recent researches have unraveled its important effect on the thermal resistance of different species of vegetative bacteria. Typically heatin...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2016.01256
更新日期:2016-08-11 00:00:00
abstract::A notable feature of the Deepwater Horizon oil spill was the unprecedented formation of marine oil snow (MOS) that was observed in large quantities floating on the sea surface and that subsequently sedimented to the seafloor. Whilst the physical and chemical processes involved in MOS formation remain unclear, some stu...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2019.00553
更新日期:2019-03-20 00:00:00
abstract::Studying the pathobiology of the fungus Aspergillus fumigatus has gained a lot of attention in recent years. This is due to the fact that this fungus is a human pathogen that can cause severe diseases, like invasive pulmonary aspergillosis in immunocompromised patients. Because alveolar macrophages belong to the first...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2015.00549
更新日期:2015-06-09 00:00:00
abstract::Gut microbiota (GM) modifies the intrahepatic immune microenvironment, but the underlying mechanisms remain poorly understood. Liver fibrosis-associated imprinting is predicted to be reflected in GM. This study investigated the link between GM and the intrahepatic T cell receptor (TCR) immune repertoire (IR), and whet...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.571847
更新日期:2020-11-27 00:00:00
abstract::The yeasts belonging to the Wickerhamiella and Starmerella genera (W/S clade) share a distinctive evolutionary history marked by loss and subsequent reinstatement of alcoholic fermentation mediated by horizontal gene transfer events. Species in this clade also share unusual features of metabolism, namely the preferenc...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2019.02510
更新日期:2019-11-01 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 environmental fate and potential impacts of nanopesticides on agroecosystems under realistic agricultural conditions are poorly understood. As a result, the benefits and risks of these novel formulations compared to the conventional products are currently unclear. Here, we examined the effects of repeated realisti...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.01769
更新日期:2018-07-31 00:00:00
abstract::The establishment of human gut microbiota commences initially in utero. Meconium-the first fecal material passed after birth-can be used to study fetal gut contents; however, processing meconium samples for microbiome studies presents significant technical challenges. Meconium hosts a low biomass microbiome, is tar-li...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.00270
更新日期:2018-02-20 00:00:00
abstract::In poultry farming, the spread of bacterial pathogens results in disease outbreaks causing significant economic losses to this industry. Many of these pathogenic bacteria are zoonotic and have a substantial impact on public health. Antimicrobials are essential for the prevention and treatment of these bacterial infect...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2019.00490
更新日期:2019-03-20 00:00:00
abstract::Sequencing and annotation was performed for two large double stranded DNA bacteriophages, φGrn1 and φSt2 of the Myoviridae family, considered to be of great interest for phage therapy against Vibrios in aquaculture live feeds. In addition, phage-host metabolic interactions and exploitation was studied by transcript pr...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2016.01807
更新日期:2016-11-14 00:00:00
abstract::Acidithiobacillus caldus is an extremely acidophilic sulfur-oxidizer with specialized characteristics, such as tolerance to low pH and heavy metal resistance. To gain novel insights into its genetic complexity, we chosen six A. caldus strains for comparative survey. All strains analyzed in this study differ in geograp...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2016.01960
更新日期:2016-12-06 00:00:00
abstract::Cathelicidins (CATHs) are host defense peptides (HDPs) that play an important role in the innate immune response against infections. Although multiple functions of cathelicidins have been described, including direct antimicrobial activity and several immunomodulatory effects on the host, relatively little is known abo...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.00426
更新日期:2020-03-19 00:00:00
abstract::Corynebacterium glutamicum is a commonly applied host for the industrial production of amino acids. While valued for its robustness, it is somewhat inferior to competing strains such as Escherichia coli because of the relatively low growth rate of 0.40 h-1 in synthetic, industrial media. Accordingly, adaptive laborato...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2019.01648
更新日期:2019-08-06 00:00:00
abstract::The complexity of the pathogenesis of inflammatory bowel disease (ulcerative colitis and Crohn's disease) has led to the quest of empirically drug therapies, combining immunosuppressant agents, biological therapy and modulators of the microbiota. Helminth parasites have been proposed as an alternative treatment of the...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.01036
更新日期:2018-05-23 00:00:00
abstract::Tuberculosis (TB) affects humans and other animals and is caused by bacteria from the Mycobacterium tuberculosis complex (MTBC). Previous studies have shown that there are at least nine members of the MTBC infecting animals other than humans; these have also been referred to as ecotypes. However, the ecology and the e...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.02820
更新日期:2018-11-27 00:00:00
abstract::In this study, we reconstructed for the first time a genome-scale metabolic model (GSMM) of Ganoderma lucidum strain CGMCC5.26, termed model iZBM1060, containing 1060 genes, 1202 metabolites, and 1404 reactions. Important findings based on model iZBM1060 and its predictions are as follows: (i) The extracellular polysa...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.03076
更新日期:2018-12-11 00:00:00
abstract::We report the isolation, characterization, and development of a robust genetic system for a halophilic, Fe(II)-oxidizing bacterium isolated from a vertical borehole originating 714 m below the surface located in the Soudan Iron Mine in northern Minnesota, USA. Sequence analysis of the 16S rRNA gene places the isolate ...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2015.00719
更新日期:2015-07-16 00:00:00
abstract::Metagenomic sequencing with the Oxford Nanopore MinION sequencer offers potential for point-of-care testing of infectious diseases in clinical settings. To improve cost-effectiveness, multiplexing of several, barcoded samples upon a single flow cell will be required during sequencing. We generated a unique sequencing ...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2018.02225
更新日期:2018-09-19 00:00:00
abstract::Fifteen years after transfer to hops, hop stunt viroid-grapevine (HSVd-g) was replaced by HSVd-hop (HSVd-h), a sequence variant that contains changes at five different positions. HSVd-g54 is a laboratory mutant derived from HSVd-g that differs from its progenitor by a single G to A substitution at position 54. While i...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2017.02427
更新日期:2017-12-12 00:00:00
abstract::Most microbes can produce surface-associated or suspended aggregates called biofilms, which are encased within a biopolymer-rich matrix. The biofilm matrix provides structural integrity to the aggregates and shields the resident cells against environmental stressors, including antibiotic treatment. Microscopy permits ...
journal_title:Frontiers in microbiology
pub_type: 杂志文章,评审
doi:10.3389/fmicb.2019.00677
更新日期:2019-04-02 00:00:00
abstract::Aerobic degradation of methylphosphonate (MPn) by marine bacterioplankton has been hypothesized to contribute significantly to the ocean's methane supersaturation, yet little is known about MPn utilization by marine microbes. To identify the microbial taxa and metabolic functions associated with MPn-driven methane pro...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2013.00340
更新日期:2013-11-26 00:00:00
abstract::We have characterized the single subunit RNA polymerase from Klebsiella phage KP34. The enzyme is unique among known bacteriophage RNA polymerases in that it recognizes two unrelated promoter sequences, which provided clues for the evolution of phage single-subunit RNA polymerases. As the first representative enzyme f...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2019.02487
更新日期:2019-10-31 00:00:00
abstract::The multi-resistant Staphylococcus capitis clone NRCS-A has recently been described as a major pathogen causing nosocomial, late-onset sepsis (LOS) in preterm neonates worldwide. NRCS-A representatives exhibit an atypical antibiotic resistance profile. Here, the complete closed genome (chromosomal and plasmid sequence...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2016.01991
更新日期:2016-12-15 00:00:00
abstract::In this study, Taisui TS-2007S, a previously unidentified biological object discovered in soil in China, was identified. TS-2007S was shown to contain abundant carbohydrates but a scarcity of protein, fat, and minerals. The exopolymers of TS-2007S showed FT-IR spectra that were similar to those of xanthan gum (XG) but...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2020.592034
更新日期:2020-11-11 00:00:00
abstract::Deinococcus radiodurans exhibits growth medium-dependent morphological variation in cell shape, but there is no evidence whether this phenomenon is observed in other members of the Deinococcaceae family. In this study, we isolated a red-pigmented, aerobic, Deinococcus indicus strain DR1 from Dadri wetland, India. This...
journal_title:Frontiers in microbiology
pub_type: 杂志文章
doi:10.3389/fmicb.2019.01449
更新日期:2019-07-03 00:00:00