scholarly journals Enterococcal Aggregation Substance and Binding Substance Are Not Major Contributors to Urinary Tract Colonization by Enterococcus faecalis in a Mouse Model of Ascending Unobstructed Urinary Tract Infection

2004 ◽  
Vol 72 (4) ◽  
pp. 2445-2448 ◽  
Author(s):  
James R. Johnson ◽  
Connie Clabots ◽  
Helmut Hirt ◽  
Christopher Waters ◽  
Gary Dunny
Keyword(s):  
Urinary Tract ◽  
Enterococcus Faecalis ◽  
Recombinant Strain ◽  
Plasmid Segregation ◽  
Cognate Receptor ◽  
Aggregation Substance ◽  
Binding Substance ◽  
Lower Urinary

ABSTRACT Isogenic Enterococcus faecalis strains that differ in their expression of aggregation substance (AS) and its cognate receptor, enterococcal binding substance (EBS), were compared for urovirulence in mice. Strain OG1SSp/pCF500 (inducible AS+, constitutive EBS+) failed to outcompete isogenic derivative INY3000 (AS− EBS−) in the urine, bladders, or kidneys of mice harvested at 48 h postinoculation. Neither mouse nor human urine induced AS expression by OG1SSp/pCF500. Recombinant strain OG1SSp/pINY1801 (constitutive AS+, EBS+) exhibited plasmid segregation that was as extensive in vivo as in vitro. These data suggest that AS and EBS do not contribute to upper or lower urinary tract colonization by E. faecalis and that growth in urine does not induce AS expression by strains carrying plasmids in the pCF10 family.

scholarly journals Antibodies to a Surface-Exposed, N-terminal Domain of Aggregation Substance Are Not Protective in the Rabbit Model of Enterococcus faecalis Infective Endocarditis

2001 ◽  
Vol 69 (5) ◽  
pp. 3305-3314 ◽  
Author(s):  
John K. McCormick ◽  
Helmut Hirt ◽  
Christopher M. Waters ◽  
Timothy J. Tripp ◽  
Gary M. Dunny ◽  
...  
Keyword(s):  
Infective Endocarditis ◽  
Enterococcus Faecalis ◽  
Rabbit Model ◽  
Surface Protein ◽  
Conjugative Plasmid ◽  
Aggregation Substance ◽  
Exposed Region ◽  
Correct Sequence

ABSTRACT The aggregation substance (AS) surface protein fromEnterococcus faecalis has been implicated as an important virulence factor for the development of infective endocarditis. To evaluate the role of antibodies specific for Asc10 (the AS protein from the conjugative plasmid pCF10) in protective immunity to infective endocarditis, an N-terminal region of Asc10 lacking the signal peptide and predicted to be surface exposed (amino acids 44 to 331; AS44–331) was cloned with a C-terminal histidine tag translational fusion and expressed fromEscherichia coli. N-terminal amino acid sequencing of the purified protein revealed the correct sequence, and rabbit polyclonal antisera raised against AS44–331 reacted specifically to Asc10 expressed from E. faecalis OG1SSp, but not to other proteins as judged by Western blot analysis. Using these antisera, flow cytometry analysis demonstrated that antibodies to AS44–331 bound to a surface-exposed region of Asc10. Furthermore, antibodies specific for AS44–331were opsonic for E. faecalis expressing Asc10 in vitro but not for cells that did not express Asc10. New Zealand White rabbits immunized with AS44–331 were challenged intravenously withE. faecalis cells constitutively expressing Asc10 in the rabbit model of experimental endocarditis. Highly immune animals did not show significant differences in clearance of organisms from the blood or spleen or in formation of vegetations on the aortic valve, in comparison with nonimmune animals. Although in vivo expression of Asc10 was demonstrated by immunohistochemistry, these experiments provide evidence that immunity to Asc10 does not play a role in protection from experimental infective endocarditis due toE. faecalis and may have important implications for the development of immunological approaches to combat enterococcal endocarditis.

In vitro and in vivo effects of endothelin-1 and YM598, a selective endothelin ETA receptor antagonist, on the lower urinary tract

2008 ◽  
Vol 580 (3) ◽  
pp. 394-400 ◽  
Author(s):  
Masashi Ukai ◽  
Hironori Yuyama ◽  
Akira Fujimori ◽  
Akiko Koakutsu ◽  
Masanao Sanagi ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Receptor Antagonist ◽  
Lower Urinary Tract ◽  
Endothelin 1 ◽  
Eta Receptor ◽  
Eta Receptor Antagonist ◽  
In Vivo Effects ◽  
Lower Urinary

Proteus mirabilis fimbriae (PMF) are important for both bladder and kidney colonization in mice

Microbiology ◽  
2003 ◽  
Vol 149 (11) ◽  
pp. 3231-3237 ◽  
Author(s):  
Pablo Zunino ◽  
Vanessa Sosa ◽  
Andrew G. Allen ◽  
Andrew Preston ◽  
Geraldine Schlapp ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Proteus Mirabilis ◽  
Bacterial Colonization ◽  
Infection Models ◽  
Uroepithelial Cells ◽  
Different Origins ◽  
Different Sources ◽  
Lower Urinary

Proteus mirabilis expresses different types of fimbriae simultaneously. Several fimbrial types have been described and their role in the colonization of the urinary tract is under study. Previously, P. mirabilis fimbriae (PMF) have been shown to be associated with bacterial colonization of the lower urinary tract but not of the kidneys. In this study, a pmfA mutant was generated and used in several in vivo and in vitro studies. Two different urinary tract infection models in the mouse and two in vitro assays of bacterial adhesion to uroepithelial cells were performed. Expression of PmfA in a collection of P. mirabilis strains of different sources was also assessed. The results shown here indicate that PMF are involved in both bladder and kidney colonization by P. mirabilis and that these fimbriae are widely distributed among P. mirabilis isolates from different origins since all strains tested expressed PmfA.

scholarly journals (p)ppGpp and CodY promoteEnterococcus faecalisvirulence in a murine model of catheter-associated urinary tract infection

2019 ◽  
Author(s):  
C Colomer-Winter ◽  
AL Flores-Mireles ◽  
S Kundra ◽  
SJ Hultgren ◽  
JA Lemos
Keyword(s):  
Urinary Tract ◽  
Enterococcus Faecalis ◽  
Urinary Tract Infections ◽  
Hospital Setting ◽  
Stringent Response ◽  
Nutrient Sensing ◽  
Transcriptional Analysis ◽  
Tract Infections

AbstractIn Firmicutes, the nutrient-sensing regulators (p)ppGpp, the effector molecule of the stringent response, and CodY work in tandem to maintain bacterial fitness during infection. Here, we tested (p)ppGpp andcodYmutant strains ofEnterococcus faecalisin a catheter-associated urinary tract infections (CAUTI) mouse model and used global transcriptional analysis to investigate the (p)ppGpp and CodY relationship. Absence of (p)ppGpp or single inactivation ofcodYled to lower bacterial loads in catheterized bladders, and diminished biofilm formation on fibrinogen-coated surfaces underin vitroandin vivoconditions. Single inactivation of the bifunctional (p)ppGpp synthetase/hydrolasereldid not affect virulence supporting previous evidence that association of (p)ppGpp with enterococcal virulence is not dependent on activation of the stringent response. Inactivation ofcodYin the (p)ppGpp0strain restoredE. faecalisvirulence in the CAUTI model as well as the ability to form biofilmsin vitro. Transcriptome analysis revealed that inactivation ofcodYrestores, for the most part, the dysregulated metabolism of (p)ppGpp0cells. While a clear linkage between (p)ppGpp and CodY with expression of virulence factors could not be established, targeted transcriptional analysis indicate that a possible association between (p)ppGpp and c-di-AMP signaling pathways in response to the conditions found in the bladder may plays a role in enterococcal CAUTI. Collectively, this study identifies the (p)ppGpp-CodY network as an important contributor to enterococcal virulence in catheterized mouse bladder and supports that basal (p)ppGpp pools and CodY promote virulence through maintenance of a balanced metabolism during adverse conditions.ImportanceCatheter-associated urinary tract infections (CAUTI) are one of the most frequent types of infection found in the hospital setting that can develop into serious and potentially fatal bloodstream infections. One of the infectious agents that frequently cause complicated CAUTI is the bacteriumEnterococcus faecalis, a leading cause of hospital-acquired infections that are often difficult to treat due to the exceptional multidrug resistance of some isolates. Understanding the mechanisms by whichE. faecaliscauses CAUTI will aid in the discovery of new druggable targets to treat these infections. In this study, we report the importance of two nutrient-sensing bacterial regulators, named (p)ppGpp and CodY, for the ability ofE. faecalisto infect the catheterized bladder of mice.

scholarly journals Obstruction-induced alterations within the urinary bladder and their role in the pathophysiology of lower urinary tract symptomatology.

2014 ◽  
Vol 8 (7-8) ◽  
pp. 524 ◽  
Author(s):  
Christos Komninos ◽  
Iraklis Mitsogiannis
Keyword(s):  
Urinary Tract ◽  
Lower Urinary Tract ◽  
Bladder Wall ◽  
Outlet Obstruction ◽  
Prostatic Hyperplasia ◽  
Animal Tissue ◽  
Urinary Tract Symptoms ◽  
Lower Urinary

Benign prostatic hyperplasia (BPH) is considered a frequent cause of bladder outlet obstruction (BOO) and lower urinary tract symptoms. This review addresses the bladder response to BOO and focuses on the alterations and biochemical adaptability of the bladder wall in the presence of hypoxia. A literature review of published articles has been performed, including both in vivo and in vitro studies on human and animal tissue.

Traceable Peptidic Ligands that Target Ghrelin Receptors

2020 ◽  
Vol 21 (10) ◽  
pp. 955-964 ◽  
Author(s):  
Mengjie Liu ◽  
John Wade ◽  
Mohammed Akhter Hossain
Keyword(s):  
In Vivo Imaging ◽  
Peptide Hormone ◽  
Structural Features ◽  
Pharmacological Properties ◽  
Imaging Studies ◽  
Cognate Receptor ◽  
Ghrelin Receptors ◽  
Biochemical Research

: Ghrelin is a 28-amino acid octanoylated peptide hormone that is implicated in many physiological and pathophysiological processes. Specific visualization of ghrelin and its cognate receptor using traceable ligands is crucial in elucidating the localization, functions, and expression pattern of the peptide’s signaling pathway. Here 12 representative radio- and fluorescently-labeled peptide-based ligands are reviewed for in vitro and in vivo imaging studies. In particular, the focus is on their structural features, pharmacological properties, and applications in further biochemical research.

scholarly journals Enterococcus faecalis exploits the human fibrinolytic system to drive excess collagenolysis: implications in gut healing and identification of druggable targets

2020 ◽  
Vol 318 (1) ◽  
pp. G1-G9 ◽  
Author(s):  
Richard A. Jacobson ◽  
Kiedo Wienholts ◽  
Ashley J. Williamson ◽  
Sara Gaines ◽  
Sanjiv Hyoju ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Healing Process ◽  
Abdominal Sepsis ◽  
Infectious Complications ◽  
Fibrinolytic System ◽  
Clinical Safety ◽  
High Concentrations ◽  
Clinically Significant

Perforations, anastomotic leak, and subsequent intra-abdominal sepsis are among the most common and feared complications of invasive interventions in the colon and remaining intestinal tract. During physiological healing, tissue protease activity is finely orchestrated to maintain the strength and integrity of the submucosa collagen layer in the wound. We (Shogan, BD et al. Sci Trans Med 7: 286ra68, 2015.) have previously demonstrated in both mice and humans that the commensal microbe Enterococcus faecalis selectively colonizes wounded colonic tissues and disrupts the healing process by amplifying collagenolytic matrix-metalloprotease activity toward excessive degradation. Here, we demonstrate for the first time, to our knowledge, a novel collagenolytic virulence mechanism by which E. faecalis is able to bind and locally activate the human fibrinolytic protease plasminogen (PLG), a protein present in high concentrations in healing colonic tissue. E. faecalis-mediated PLG activation leads to supraphysiological collagen degradation; in this study, we demonstrate this concept both in vitro and in vivo. This pathoadaptive response can be mitigated with the PLG inhibitor tranexamic acid (TXA) in a fashion that prevents clinically significant complications in validated murine models of both E. faecalis- and Pseudomonas aeruginosa-mediated colonic perforation. TXA has a proven clinical safety record and is Food and Drug Administration approved for topical application in invasive procedures, albeit for the prevention of bleeding rather than infection. As such, the novel pharmacological effect described in this study may be translatable to clinical trials for the prevention of infectious complications in colonic healing. NEW & NOTEWORTHY This paper presents a novel mechanism for virulence in a commensal gut microbe that exploits the human fibrinolytic system and its principle protease, plasminogen. This mechanism is targetable by safe and effective nonantibiotic small molecules for the prevention of infectious complications in the healing gut.

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