Virulence of haemolytic strains of in various animal models

Vandenbosch, J L; Emödy, Levente; Kétyi, I

doi:10.1016/0378-1097(82)90204-x

Cited by 11 publications

(10 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is well known that UPEC bacteria utilize type 1 fimbriae (fim) (5) and pyelonephritis-associated pili (pap) (34) to establish and maintain infection in the urinary tract. Additionally, UPEC bacteria possess the ability to secrete toxins such as CNF1 (33), hemolysin (48,51), and autotransporters (11,12) to produce cytotoxic effects in the host and thus contribute to UPEC virulence. It has been shown that the murine urinary tract is an iron-limiting environment (42); consequently, UPEC bacteria contain multiple iron acquisition systems that allow the pathogen to survive and replicate within the urinary tract by scavenging iron molecules sequestered by the host (27,36,40,45).…”

mentioning

confidence: 99%

Quantitative Profile of the Uropathogenic Escherichia coli Outer Membrane Proteome during Growth in Human Urine

Alteri

Mobley

2007

Infection and Immunity

View full text Add to dashboard Cite

Outer membrane proteins (OMPs) of microbial pathogens are critical components that mediate direct interactions between microbes and their surrounding environment. Consequently, the study of OMPs is integral to furthering the understanding of host-pathogen interactions and to identifying key targets for development of improved antimicrobial agents and vaccines. In this study, we used two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and tandem mass spectrometry to characterize the uropathogenic Escherichia coli (UPEC) outer membrane subproteome; 30 individual OMPs present on the bacterial surface during growth in human urine were identified. Fluorescence difference gel electrophoresis was used to identify quantitative changes in levels of UPEC strain CFT073 OMPs during growth in urine; six known receptors for iron compounds were induced in this environment, i.e., ChuA, IutA, FhuA, IroN, IreA, and Iha. A seventh putative iron compound receptor, encoded by CFT073 open reading frame (ORF) c2482, was also identified and found to be induced in urine. Further, the induction of these seven iron receptors in human urine and during defined iron limitation was verified by using quantitative real-time PCR (qPCR). An eighth iron receptor, fepA, displayed similar induction levels under these conditions as measured by qPCR but was not identified by 2D-PAGE. Addition of 10 M FeCl 2 to human urine repressed the transcription of all eight iron receptor genes. A number of fecal-commensal, intestinal pathogenic, and uropathogenic E. coli strains all displayed similar growth rates in human urine, showing that the ability to grow in urine per se is not a urovirulence trait. Thus, human urine is an iron-limiting environment and UPEC enriches its outer membrane with iron receptors to contend with this iron limitation.The bacterial outer membrane represents the critical interface between the microorganism and its environment. For pathogenic bacteria, the proteins localized to the outer membrane directly interact with components of the host and can act as adhesins or receptors to facilitate colonization and mediate acquisition of nutrients and macromolecules from this restrictive niche (6,26). Because these proteins are surface exposed, they are attractive targets for the development of improved antimicrobial agents and vaccines to eradicate infecting microorganisms or stimulate protective immune responses such as neutralizing or opsonizing immunoglobulins (10, 21). Elucidating the composition and profile of bacterial outer membrane proteins can help to better understand how specific bacterial pathogens interact with the host and to identify potential therapeutic targets.Uropathogenic Escherichia coli (UPEC) bacteria are extraintestinal pathogens that cause the majority of uncomplicated urinary tract infections (UTI) (49). It has been determined that these infections impact public health by exacting more than two billion dollars of health care costs annually (7,19). It is well known that UPEC bacteria utilize type 1 fimbriae (...

show abstract

mentioning

confidence: 99%

Quantitative Profile of the Uropathogenic Escherichia coli Outer Membrane Proteome during Growth in Human Urine

Alteri

Mobley

2007

Infection and Immunity

View full text Add to dashboard Cite

show abstract

“…Following these results strain 536 was termed as mouse nephrovirulent. 32 Renal bacterial counts of strain 536-31 decreased within the time period of eight hours but infection of mice with that strain resulted in a higher number of bacteria per kidney than inoculation of 536-21 cells. Strains 536-21 and 536-31 were defined as non-nephrovirulent, although it is interesting to note that S-fimbriae and serum resistance had a small influence on renal bacterial counts.…”

Section: Number Of Bacteria In the Kidney After I V Infectionmentioning

confidence: 97%

Influence of cloned Escherichia coli hemolysin genes, S-fimbriae and serum resistance on pathogenicity in different animal models

Hacker

Hof

Emödy

et al. 1986

Microbial Pathogenesis

View full text Add to dashboard Cite

of cloned hemolysin genes, S-fimbriae and serum resistance on pathogenicity in different animal models. Microbial Pathogenesis 1986; 1: 000-000.The virulence of the uropathogenic E. coli strain 536 (06: K 1 5: H31) which produces the S-fimbrial adhesin (Sfa•), is serum-resistant (Sre+) and hemolytic (Hiy+) and its derivatives were assessed in five different animal models. Cloned hemolysin (h/y) determinants from the Chromosomes of 06,018 and 075 E. colistrains and from the plasmid pHiy152 were introduced into the spontaneaus Sfa-, Sre-, Hly-mutant 536-21 and its Sfa+, Sre+, Hly-variant 536-31. As already demonstrated for the 536-21 strains {lnfect. Immun. 42: 57-63) the 018-hly determinant but not the plasmid-encoded hly determinant of pHiy 1 52 transformed into 536-31 contribute to lethality in a mouse peritonitis modal. Similar results were obtained with both Hlyhost strains and their Hly+ transformants in a chicken embryo test and in a mouse nephropathogenicity assay in which the renal bacterial counts were measured 1 5 min to 8 hours after i.v. infection. S-fimbriae and serum resistance had only a marginal influence in these three in vivo systems. ln centrast all three factors, S-fimbriae, serum resistance and hemolysin, were necessary for full virulence in a respiratory mouse infection assay. ln a subcutaneously-induced sepsis model in the mouse restoration of S-fimbriae and serum resistance and separately chromosomally-encoded hemolysis increased virulence to a Ievel comparable to that of the parental 536 strain.Key words: E. coli hemolysin. S-fimbriae; serum resistance. E. coli virulence; animal models; gene cloning. lntroductionEscherichia coli strains are responsible for most urinary tract infections (UTI). Certain E. coli clones cause neonatal sepsis and meningitis. 1 -3 Many cell components such as adhesins, serum resistance factors, cytolysins and others have been shown to be associated with extraintestinal virulence in E. coli. 4 Adhesion factors which recognize galactosyl-galactose receptors (P fimbriae 2 · 5 ) are common among UTI strains. S-fimbriae specifically bind to sialic acid containing structures are frequently associated with isolates from cases of newborn meningitis.3·6 The genetic determinants for S~fimbrial adhesins (sfa) cover a stretch of

show abstract

“…A number of virulence determinants facilitate the ability of UPEC to colonize the urinary tract and exert cytopathic effects, including type 1 fimbriae (6), P fimbriae (39), Dr adhesins (12), hemolysin (52,53), cytotoxic necrotizing factor 1 (37), flagella (25), capsule polysaccharide (2), lipopolysaccharide O antigen (44), and TonB-dependent iron transport systems (50). Recently, the determination of the in vivo transcriptome of UPEC further emphasized the importance of adhesion and iron acquisition during UTI, because genes involved in these processes were highly upregulated during experimental infection (46).…”

mentioning

confidence: 99%

Uropathogenic Escherichia coli Outer Membrane Antigens Expressed during Urinary Tract Infection

2007

View full text Add to dashboard Cite

Uncomplicated urinary tract infection (UTI) caused by uropathogenic Escherichia coli (UPEC) represents a prevalent and potentially severe infectious disease. In this study, we describe the application of an immunoproteomics approach to vaccine development that has been used successfully to identify vaccine targets in other pathogenic bacteria. Outer membranes were isolated from pyelonephritis strain E. coli CFT073 cultured under conditions that mimic the urinary tract environment, including iron limitation, osmotic stress, human urine, and exposure to uroepithelial cells. To identify antigens that elicit a humoral response during experimental UTI, outer membrane proteins were separated by two-dimensional gel electrophoresis and probed using pooled antisera from 20 CBA/J mice chronically infected with E. coli CFT073. In total, 23 outer membrane antigens, including a novel iron compound receptor, reacted with the antisera and were identified by mass spectrometry. These antigens also included proteins with known roles in UPEC pathogenesis, such as ChuA, IroN, IreA, Iha, IutA, and FliC. These data demonstrate that an antibody response is directed against these virulenceassociated factors during UTI. We also show that the genes encoding ChuA, IroN, hypothetical protein c2482, and IutA are significantly more prevalent (P < 0.01) among UPEC strains than among fecal-commensal E. coli isolates. Thus, we suggest that the conserved outer membrane antigens identified in this study could be rational candidates for a UTI vaccine designed to elicit protective immunity against UPEC infection.

show abstract

Virulence of haemolytic strains of in various animal models

Cited by 11 publications

References 2 publications

Quantitative Profile of the Uropathogenic Escherichia coli Outer Membrane Proteome during Growth in Human Urine

Quantitative Profile of the Uropathogenic Escherichia coli Outer Membrane Proteome during Growth in Human Urine

Influence of cloned Escherichia coli hemolysin genes, S-fimbriae and serum resistance on pathogenicity in different animal models

Uropathogenic Escherichia coli Outer Membrane Antigens Expressed during Urinary Tract Infection

Contact Info

Product

Resources

About