lipid-a and Urinary-Tract-Infections

Topics: Adult; Animals; Antibody Formation; Antibody-Coated Bacteria Test, Urinary; Autoantibodies; Child; Cystitis; Female; Humans; Immunity, Cellular; Immunologic Techniques; Infant; Infant, Newborn; Lipid A; Male; Mucoproteins; Neutrophils; Pregnancy; Pregnancy Complications, Infectious; Prognosis; Pyelonephritis; Urinary Tract Infections; Uromodulin

Urinary tract infections (UTIs) caused by Escherichia coli and Proteus mirabilis are an important cause of morbidity and with the high rate of relapse and spread of multi-drug resistant pathogens, pose a significant public health challenge worldwide. Lack of an efficacious commercial vaccine targeting both uropathogens makes development of a combined vaccine highly desirable. In this study the immunogenicity and protective efficacy of different formulations of FimH of UPEC, MrpH of P. mirabilis and their fusion protein (MrpH.FimH) subcutaneously administered with and without Monophosphoryl lipid A (MPL) adjuvant were evaluated. Our data showed that the subcutaneously administered proteins induced both serum and mucosal IgG, which MPL significantly improved developing a mixed Th1 and Th2 immune response. However, the preparations induced a higher systemic and mucosal IgG and IL-2 levels by this route compared to the intranasal. Immunization of mice with MrpH.FimH fusion with MPL or a mixture of FimH, MrpH and MPL conferred the highest protection of the bladder and kidneys when challenged with UPEC and P. mirabilis in a UTI mouse model. Therefore considering these results MrpH.FimH fusion with MPL administered subcutaneously or intranasally could be a promising vaccine candidate for elimination of UTIs caused by UPEC and P. mirabilis.

Topics: Adhesins, Bacterial; Adhesins, Escherichia coli; Adjuvants, Immunologic; Administration, Intranasal; Animals; Antibodies, Bacterial; Female; Fimbriae Proteins; Immunoglobulin G; Injections, Subcutaneous; Interleukin-2; Kidney; Lipid A; Mice; Mice, Inbred BALB C; Proteus mirabilis; Th1 Cells; Th2 Cells; Urinary Bladder; Urinary Tract Infections; Uropathogenic Escherichia coli

Bacterial infection of the kidney is associated with renal tubule dysfunction and dysregulation of systemic electrolyte balance. Whether bacterial molecules directly affect renal tubule transport is unknown. We examined the effects of LPS on HCO3(-) absorption in the isolated rat and mouse medullary thick ascending limb (MTAL). LPS decreased HCO3(-) absorption when added to bath or lumen. The MEK/ERK inhibitor U0126 eliminated inhibition by bath LPS but had no effect on inhibition by lumen LPS. Conversely, the mammalian target of rapamycin (mTOR) inhibitor rapamycin eliminated inhibition by lumen LPS but had no effect on inhibition by bath LPS. Inhibiting basolateral Na(+)/H(+) exchange with amiloride eliminated inhibition of HCO3(-) absorption by lumen but not bath LPS. Confocal immunofluorescence showed expression of TLR4 in basolateral and apical membrane domains. Inhibition of HCO3(-) absorption by bath and lumen LPS was eliminated in MTALs from TLR4(-/-) mice. Thus LPS inhibits HCO3(-) absorption through distinct TLR4-dependent pathways in basolateral and apical membranes. These results establish that bacterial molecules can directly impair the transport function of renal tubules, identifying a new mechanism contributing to tubule dysfunction during bacterial infection. The LPS-induced reduction in luminal acidification may contribute to Gram-negative pathogenicity by promoting bacterial adherence and growth and impairing correction of infection-induced systemic acid-base disorders.

Topics: Amiloride; Animals; Bicarbonates; Butadienes; Disease Progression; Endotoxemia; Escherichia coli Infections; Escherichia coli K12; Immunity, Innate; In Vitro Techniques; Kidney Tubules; Lipid A; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Nitriles; Rats; Rats, Sprague-Dawley; Serum; Signal Transduction; Sirolimus; Toll-Like Receptor 4; Urinary Tract Infections

Bacterial infection of the mouse urinary tract is followed by the recruitment of leukocytes to the mucosal surface. This study examined the bacterial components involved in the induction of this response. Escherichia coli of serotype O75:K5:H- expressing adhesins specific for the Gal alpha 1-4Gal beta- (Gal, galactose) and mannose-containing receptors were instilled into the urinary bladder of lipopolysaccharide responder (C3H/HcN) and lipopolysaccharide nonresponder (C3H/HeJ) mice. The inflammation was quantitated as the number of leukocytes excreted into the urine at various times after infection. The response was first shown to depend on the Lps genotype of the mouse. The leukocyte excretion that occurred within 24 h after infection of C3H/HeN mice was absent in C3H/HeJ mice. The components triggering the response were present on both live and Formalin-killed bacterial cells, and the response was mimicked by intravesical inoculation of isolated lipid A. Pretreatment of bacteria with soluble receptor oligosaccharides resulted in inhibition of attachment in vitro and of the inflammation in vivo. A direct synergy between adhesins specific for Gal alpha 1-4Gal beta receptors and lipid A was demonstrated. Mixtures of these components induced a leukocyte response higher than the sum of the responses to each component alone. These results suggest that the inflammation induced by gram-negative bacteria in the urinary tract can be triggered at the level of the epithelial cells by endotoxin presented by an attaching bacterial cell and that intact function at the Lps locus of the host is required for this to occur.

Topics: Animals; Bacterial Adhesion; Endotoxins; Escherichia coli; Escherichia coli Infections; Fimbriae, Bacterial; Galactosides; Genes; Inflammation; Lipid A; Mannosides; Mice; Mice, Inbred Strains; Mucous Membrane; Urinary Tract Infections

Topics: Animals; Bacterial Adhesion; Endotoxins; Escherichia coli Infections; Glycolipids; Humans; Indomethacin; Inflammation; Lipid A; Mice; Urinary Tract Infections

From the studies of Westenfelder et al. and our own studies of the presence of lipid A antibodies in the upper and lower urinary tract infections, it can be concluded that chronic pyelonephritis is a lipid A induced disease. This hypothesis is based on the distinct statistically different antibody production in upper urinary tract infection in contrast to lower urinary tract infection, the persistence of lipid A in renal tissue, as well as the induction of lipid A nephritis in puppies. These observations should be considered in future studies to proceed in the clarification of these diseases.

Topics: Animals; Antibodies, Bacterial; Child; Chronic Disease; Dogs; Enzyme-Linked Immunosorbent Assay; Humans; Lipid A; Pyelonephritis; Urinary Tract Infections

The serum titres of IgG and IgM antibodies to lipid A were measured in 24 children with chronic pyelonephritis (PN), 55 with recurrent lower urinary tract infections (LUTI), 13 with gram-negative sepsis (S), and in 50 control children using an enzyme-linked immunosorbent assay (ELISA). Children ranged in age from 1 month-17 years. Patients with PN were differentiated by the presence or absence of an acute infectious episode and/or vesico-ureteric reflux (VUR). During an acute episode in PN and LUTI, IgG titres were significantly higher than in controls, but only PN patients with an acute infectious episode also had significantly elevated IgM titres. Overall, children with LUTI showed a significantly lower frequency of detectable IgG lipid A antibodies (27%) than in PN (63%). In PN children with VUR not accompanied by an infectious episode, lipid A antibody was found at relatively low titres, while an episode not accompanied by VUR displayed significantly elevated IgG titres, and an episode accompanied by VUR showed elevation of both IgG and IgM anti-lipid A antibody titres.

Topics: Adolescent; Child; Child, Preschool; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunoglobulin G; Immunoglobulin M; Infant; Lipid A; Male; Pyelonephritis; Recurrence; Sepsis; Urinary Tract Infections; Vesico-Ureteral Reflux

Lipid A is the toxic component of endotoxin in gram-negative bacteria. Antibodies to lipid A are not usually found in healthy persons (or only at a low titer) without a corresponding history of infection. Even gram-negative septicemia is found to be accompanied by only low titers. A completely different situation is seen in patients with chronic or recurrent infections due to Enterobacteriaceae and other gram-negative bacteria. Here it is notable that the antibody titer varies with the type of disorder (e. g. cystitis and pyelonephritis). A severe would infection, e. g. due to Pseudomonas aeruginosa, also leads to measurable lipid A antibody titers. Varying antibody titers can be observed in cystic fibrosis, Crohn's disease, and severe surgical infections. One can conclude that a significantly elevated antibody titer develops during an extensive tissue involvement of long duration and indeed is caused by tissue inhibition by endotoxin. Based on clinical experience, it can be assumed that lipid A antibodies present in the body have a protective effect in septic shock.

Topics: Adolescent; Adult; Antitoxins; Bacterial Infections; Child; Enterobacteriaceae Infections; Humans; Immunoglobulin G; Lipid A; Pyelonephritis; Sepsis; Urinary Tract Infections; Wound Infection

The levels of IgG- and IgM-antibodies against lipid A were determined by an ultramicro-ELISA in 54 children between 2 months and 13 years of age with non-obstructive urinary tract infections at the onset of the infection and subsequently after 3, 6 and 12 months. Children older than 2 years who later developed renal scarring as shown by intravenous pyelograms had higher levels of IgG antibodies than those without scars. This correlation was not found in children younger than 2 years of age. IgM-antibody levels did not correlate with the risk of scar formation. We conclude that the IgG-antibody level against lipid A is a useful indicator for early recognition of children over the age of two years who will later develop renal scars. The ultramicro-ELISA technique makes screening for children at risk possible at a low cost.

Topics: Adolescent; Bacterial Infections; Child; Child, Preschool; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunoglobulin G; Immunoglobulin M; Infant; Kidney Diseases; Lipid A; Male; Pyelonephritis; Risk; Urinary Tract Infections

The difference in susceptibility to urinary tract infection between C3H/HeJ and C3H/HeN mice was tested for with gram-negative strains differing in lipopolysaccharide composition. Recently, impaired clearance of Escherichia coli from the kidney of C3H/HeJ compared to C3H/HeN mice was shown to be correlated with the LPS low responsiveness. In this study, a difference in clearance from the kidneys of C3H/HeJ and C3H/HeN mice was found only with lipopolysaccharide-containing bacteria. Gram-positive bacteria, e.g., Staphylococcus saprophyticus and Streptococcus agalactiae, were recovered in essentially equal numbers from the kidneys of mice of both strains. In contrast, of the lipopolysaccharide-containing strains used, all persisted in higher numbers in the kidneys of C3H/HeJ mice than in the kidneys of C3H/HeN mice. Variations in the O side chain did not eliminate this difference. E. coli Hu734 O75+K5+ and the rfb- mutant O75-K5+ remained in similar numbers in C3H/HeJ mice, although O75-K5+ was eliminated more rapidly in C3H/HeN mice. The core structure did not affect the differential persistence in the two mouse strains. The rfb mutants with R1-R4 cores were eliminated after 24 h from the C3H/HeN mice, but remained in significant numbers in the kidneys of C3H/HeJ mice. Even the Re mutant of Salmonella minnesota persisted in low numbers in C3H/HeJ mice. The relative bacterial recovery from either mouse strain was related to the overall virulence of the infecting bacterial strain, but the difference between C3H/HeJ and C3H/HeN mice was associated with responsiveness to parts of lipopolysaccharide common to the bacterial strains tested.

Topics: Animals; Antigens, Bacterial; Escherichia coli; Kidney; Lipid A; Lipopolysaccharides; Mice; Mice, Inbred C3H; Polysaccharides, Bacterial; Urinary Tract Infections

Serum levels of antibodies to lipid A were determined with an enzyme-linked immunosorbent assay in 26 girls with their first known symptomatic urinary tract infection (UTI) and in 15 girls with asymptomatic bacteriuria (ABU). Also included were six female patients with recurrence of acute upper UTI, five of whom had renal changes after the infections; 28 female patients with renal scarring but not symptomatic UTI at the time of investigation; and uninfected individuals. IgG and IgM antibodies to lipid A were found in approximately 50% of the uninfected children older than two years of age. Girls with acute cystitis, acute pyelonephritis, or ABU showed significantly elevated levels of IgG antibodies to lipid A as compared with children with no history of UTI. High levels of IgG antibodies to lipid A may be indicative of severe renal infection and development or progression of renal parenchymal reduction. The diagnostic value of determining levels of antibodies to lipid A is discussed.

Topics: Adolescent; Bacteriuria; Child; Child, Preschool; Cystitis; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunoglobulin G; Immunoglobulin M; Infant; Lipid A; Lipopolysaccharides; Pyelonephritis; Urinary Tract Infections

Lipid A antibody titers were measured by the passive hemolysis test in 349 humans. In two out of 20 healthy adults and 16 out of 18 children with recurrent urinary tract infection (UTI) in the presence of anomalies anti-lipid A antibodies were present. In contrast, no titers were found in 23 newborn babies. In a group of 156 patients with acute UTI, 28% revealed positive titers, whereas in a group of 132 patients with recurrent UTI titers occurred in 81%. In a selected group of 132 patients with recurrent infections of the upper tract 59 (=96%) showed definite titers. There was no difference in the development of anti-lipid A antibodies between men and women and the height of the titers did not correlate with the clinical picture of the disease (acute or chronic). The combination of proteinuria and anti-lipid A antibodies indicates the presence of recurrent UTI or chronic pyelonephritis with about 90% accuracy. The titers are caused by immunogenically active lipid A in the body. Since lipid A has the ability to remain in the renal tissue for a long period of time and thereby to maintain the inflamatory response, long-term antimicrobial prophylaxis (six months) should be given to patients with a high risk of recurrent UTI.

Topics: Adolescent; Adult; Antibodies, Bacterial; Antibody Formation; Child; Child, Preschool; Endotoxins; Humans; Infant; Lipid A; Lipopolysaccharides; Urinary Tract Infections