Abstract:
BACKGROUND:Enterohemorrhagic Escherichia coli (EHEC) colonizes the intestinal epithelium and causes attaching and effacing (A/E) lesions. Expression of virulence genes, particularly those from the locus of the enterocyte effacement (LEE) pathogenicity island is required for the formation of a type three secretion system, which induces A/E lesion formation. Like other horizontally acquired genetic elements, expression of the LEE is negatively regulated by H-NS. In the non-pathogenic Escherichia coli K-12 strain the stringent starvation protein A (SspA) inhibits accumulation of H-NS, and thereby allows de-repression of the H-NS regulon during the stationary phase of growth. However, the effect of SspA on the expression of H-NS-controlled virulence genes in EHEC is unknown. RESULTS:Here we assess the effect of SspA on virulence gene expression in EHEC. We show that transcription of virulence genes including those of the LEE is decreased in an sspA mutant, rendering the mutant strain defective in forming A/E lesions. A surface exposed pocket of SspA is functionally important for the regulation of the LEE and for the A/E phenotype. Increased expression of ler alleviates LEE expression in an sspA mutant, suggesting that the level of Ler in the mutant is insufficient to counteract H-NS-mediated repression. We demonstrate that the H-NS level is two-fold higher in an sspA mutant compared to wild type, and that the defects of the sspA mutant are suppressed by an hns null mutation, indicating that hns is epistatic to sspA in regulating H-NS repressed virulence genes. CONCLUSIONS:SspA positively regulates the expression of EHEC virulence factors by restricting the intracellular level of H-NS. Since SspA is conserved in many bacterial pathogens containing horizontally acquired pathogenicity islands controlled by H-NS, our study suggests a common mechanism whereby SspA potentially regulates the expression of virulence genes in these pathogens.
journal_name
BMC Microbioljournal_title
BMC microbiologyauthors
Hansen AM,Jin DJdoi
10.1186/1471-2180-12-231subject
Has Abstractpub_date
2012-10-11 00:00:00pages
231issn
1471-2180pii
1471-2180-12-231journal_volume
12pub_type
杂志文章相关文献
BMC MICROBIOLOGY文献大全abstract:BACKGROUND:Acetic acid has been used to clean and disinfect surfaces in the household for many decades. The antimicrobial efficacy of cleaning procedures can be considered particularly important for young, old, pregnant, immunocompromised people, but may also concern other groups, particularly with regards to the COVID...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-020-01948-8
更新日期:2020-08-26 00:00:00
abstract:BACKGROUND:Accumulation of gyrase cleavage complex in Escherichia coli from the action of quinolone antibiotics induces an oxidative damage cell death pathway. The oxidative cell death pathway has also been shown to be involved in the lethality following accumulation of cleavage complex formed by bacterial topoisomeras...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/1471-2180-11-261
更新日期:2011-12-12 00:00:00
abstract:BACKGROUND:Biofilm formation by Candida albicans has shown to be highly variable and is directly associated with pathogenicity and poor clinical outcomes in patients at risk. The aim of this study was to test the hypotheses that the extracellular DNA release by C. albicans is strain dependent and is associated with bio...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-014-0303-6
更新日期:2014-12-05 00:00:00
abstract:BACKGROUND:Campylobacter jejuni (C. jejuni) is a leading cause of foodborne gastroenteritis worldwide. This bacterium lacks many of the classical virulence factors, and flagellum-associated persistent colonization has been shown to be crucial for its pathogenesis. The flagellum plays a multifunctional role in C. jejuni...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-018-1318-1
更新日期:2018-10-22 00:00:00
abstract:BACKGROUND:Generation of extended- spectrum β- lactamases is one of the major mechanisms by which clinical Klebsiella pneumoniae develop resistance to antibiotics. Combined antibiotics prove to be a relatively effective method of controlling such resistant strains. Some of Chinese herbal active ingredients are known to...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-016-0797-1
更新日期:2016-08-08 00:00:00
abstract:BACKGROUND:The infections caused by antibiotic multidrug-resistant bacteria seriously threaten human health. To prevent and cure the infections caused by multidrug-resistant bacteria, new antimicrobial agents are required. Antimicrobial peptides are ideal therapy candidates for antibiotic-resistant pathogens. However, ...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-015-0389-5
更新日期:2015-03-03 00:00:00
abstract:BACKGROUND:The gene encoding the inorganic pyrophosphatase (PPase) of the intracellular pathogen Legionella pneumophila is induced during intracellular infection, but is constitutively expressed in Escherichia coli. The causative agent of tuberculosis, Mycobacterium tuberculosis, contains a well conserved copy of PPase...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/1471-2180-1-3
更新日期:2001-01-01 00:00:00
abstract:: ...
journal_title:BMC microbiology
pub_type:
doi:10.1186/s12866-018-1279-4
更新日期:2018-11-23 00:00:00
abstract:BACKGROUND:Modifiable lifestyle factors (e.g. dietary intake and physical activity) are important contributors to weight gain during college. The purpose of this study was to evaluate whether associations exist between body mass index, physical activity, screen time, dietary consumption (fat, protein, carbohydrates, an...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-018-1362-x
更新日期:2018-12-12 00:00:00
abstract:BACKGROUND:Bacterial nucleoid consists of genome DNA, RNA, and hundreds of nucleoid-associated proteins (NAPs). Escherichia coli nucleoid is compacted towards the stationary phase, replacing most log-phase NAPs with the major stationary-phase nucleoid protein, Dps. In contrast, Staphylococcus aureus nucleoid sustains t...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-017-1114-3
更新日期:2017-10-02 00:00:00
abstract:BACKGROUND:Adhesion to surfaces facilitates many crucial functions of microbes in their natural habitats. Thus understanding the mechanism of microbial adhesion is of broad interest to the microbiology research community. RESULTS:We report a study by fluorescence imaging and atomic force microscopy on the growth in si...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/1471-2180-13-139
更新日期:2013-06-19 00:00:00
abstract:BACKGROUND:Legionella pneumophila, the causative agent of Legionnaire's disease, may enter a viable but non-culturable (VBNC) state triggered by environmental stress conditions. Specific outer-membrane epitopes of L. pneumophila are used in many diagnostic applications and some of them are linked to important virulence...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-018-1220-x
更新日期:2018-07-17 00:00:00
abstract:BACKGROUND:HSV-1 is a common pathogen that infects 50-90% of the human population worldwide. HSV-1 causes numerous infection-related diseases, some of which are severely life-threatening. There are antiviral medications with activity against HSV-1. However, with the emergence of drug-resistant mutant strains of HSV-1, ...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-019-1639-8
更新日期:2019-12-07 00:00:00
abstract:BACKGROUND:The high demand for ethanol in the U.S. has generated large stocks of wet distillers grains (DG), a byproduct from the manufacture of ethanol from corn and sorghum grains. Little is known, however, about the potential influence of dietary DG on fecal microbial community structure. A better understanding of t...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/1471-2180-12-25
更新日期:2012-02-24 00:00:00
abstract:BACKGROUND:A major obstacle to industrial-scale astaxanthin production by the yeast Phaffia rhodozyma is the strong inhibitory effect of high glucose concentration on astaxanthin synthesis. We investigated, for the first time, the mechanism of the regulatory effect of high glucose (> 100 g/L) at the metabolite and tran...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-019-1507-6
更新日期:2019-06-15 00:00:00
abstract:BACKGROUND:Many plants have been used in traditional medicine for their antibacterial, antifungal, antiprotozoal, antiviral, antidiarrhoeal, analgesic, antimalarial, antioxidant, anti-inflammatory and anticancer activities. In order to find novel antimicrobial and antiviral agents, the aim of the present study was the ...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-017-1068-5
更新日期:2017-07-14 00:00:00
abstract:BACKGROUND:The purpose of this study was to design and evaluate fluorescent in situ hybridization (FISH) probes for the single-cell detection and enumeration of lactic acid bacteria, in particular organisms belonging to the major phylogenetic groups and species of oral lactobacilli and to Abiotrophia/Granulicatella. R...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/1471-2180-11-14
更新日期:2011-01-19 00:00:00
abstract:BACKGROUND:Cryptosporidium spp. and Giardia duodenalis are important causes of diarrheal diseases in humans and animals worldwide, and there is an increased interest in the role of animals in the mechanical transmission of these protozoa. To examine the role of yaks in this process, we examined the occurrence and genot...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-015-0446-0
更新日期:2015-05-21 00:00:00
abstract:BACKGROUND:Candida albicans yeast produces 10 distinct secreted aspartic proteases (Saps), which are some of the most important virulence factors of this pathogenic fungus. One of the suggested roles of Saps is their deregulating effect on various proteolytic cascades that constitute the major homeostatic systems in hu...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-015-0394-8
更新日期:2015-03-04 00:00:00
abstract:BACKGROUND:Similar to Gram-negative bacteria, the outer membrane (OM) of the pathogenic spirochete, Borrelia burgdorferi, contains integral OM-spanning proteins (OMPs), as well as membrane-anchored lipoproteins. Although the mechanism of OMP biogenesis is still not well-understood, recent studies have indicated that a ...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/1471-2180-12-60
更新日期:2012-04-20 00:00:00
abstract:BACKGROUND:Aspergillus fumigatus is a ubiquitous saprotrophic fungus and an opportunistic pathogen of humans and animals. Humans and animals can inhale hundreds of A. fumigatus spores daily. Normally this is harmless for humans, but in case of immunodeficiency, invasive pulmonary aspergillosis (IPA) can develop with a ...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-018-1244-2
更新日期:2018-09-17 00:00:00
abstract:BACKGROUND:Classical bacteriological characteristics of Salmonella enterica indicate that the members of this species are unable to utilize lactose as a carbon source. However, lactose-fermenting (Lac+) strains of several Salmonella serovars have been isolated from different foodborne outbreaks as well as different geo...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-015-0511-8
更新日期:2015-08-25 00:00:00
abstract:BACKGROUND:Vibrio cholerae is the causative agent of cholera. Extensive studies reveal that complicated regulatory cascades regulate expression of virulence genes, the products of which are required for V. cholerae to colonize and cause disease. In this study, we investigated the expression of the key virulence regulat...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/1471-2180-10-3
更新日期:2010-01-06 00:00:00
abstract:BACKGROUND:The skin microbiome serves as a first line defense against pathogens in vertebrates. In amphibians, it has the potential to protect against the chytrid fungus Batrachochytrium dendrobatis (Bd), a likely agent of amphibian declines. Alteration of the microbiome associated with unfavorable environmental change...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-020-01979-1
更新日期:2020-09-22 00:00:00
abstract:BACKGROUND:Mosquitoes are intermediate hosts for numerous disease causing organisms. Vector control is one of the most investigated strategy for the suppression of mosquito-borne diseases. Anopheles stephensi is one of the vectors of malaria parasite Plasmodium vivax. The parasite undergoes major developmental and matu...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/1471-2180-9-96
更新日期:2009-05-19 00:00:00
abstract:BACKGROUND:Iron is an essential nutrient but can be toxic at high intracellular concentrations and organisms have evolved tightly regulated mechanisms for iron uptake and homeostasis. Information on iron management mechanisms is available for organisms living at circumneutral pH. However, very little is known about how...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/1471-2180-8-203
更新日期:2008-11-24 00:00:00
abstract:BACKGROUND:The naked mole-rat (NMR, Heterocephalus glaber) is being bred as a novel laboratory animal due to its unique biological characteristics, including longevity, cancer resistance, hypoxia tolerance, and pain insensitivity. It is expected that differences exist between the microbiota of wild NMRs and that of NMR...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-018-1226-4
更新日期:2018-08-22 00:00:00
abstract:BACKGROUND:Extended-spectrum cephalosporin resistance (ESC-R) in Escherichia coli and Klebsiella pneumoniae is a healthcare threat; high gastrointestinal carriage rates are reported from South-east Asia. Colonisation prevalence data in Cambodia are lacking. The aim of this study was to determine gastrointestinal coloni...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-019-1431-9
更新日期:2019-03-12 00:00:00
abstract:BACKGROUND:Macrolide antibiotics are commonly administered for bacterial respiratory illnesses. Azithromycin (Az) is especially noted for extremely high intracellular concentrations achieved within macrophages which is far greater than the serum concentration. Clinical strains of Type B Francisella (F.) tularensis have...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/1471-2180-10-123
更新日期:2010-04-23 00:00:00
abstract:BACKGROUND:Macrolides and lincosamides are two leading types of antibiotics commonly used in therapies. The study examines the differences in resistance to these antibiotics and their molecular bases in S. epidermidis as well as in rarely isolated species of coagulase-negative staphylococci such as S. hominis, S. haemo...
journal_title:BMC microbiology
pub_type: 杂志文章
doi:10.1186/s12866-019-1496-5
更新日期:2019-06-10 00:00:00