lactoferrin and Bacteremia

To evaluate the safety and explore the efficacy of recombinant human lactoferrin (talactoferrin [TLf]) to reduce infection.. We conducted a randomized, double blind, placebo-controlled trial in infants with birth weight of 750-1500 g. Infants received enteral TLf (n = 60) or placebo (n = 60) on days 1 through 28 of life; the TLf dose was 150 mg/kg every 12 hours. Primary outcomes were bacteremia, pneumonia, urinary tract infection, meningitis, and necrotizing enterocolitis (NEC). Secondary outcomes were sepsis syndrome and suspected NEC. We recorded clinical, laboratory, and radiologic findings, along with diseases and adverse events, in a database used for statistical analyses.. Demographic data were similar in the 2 groups of infants. We attributed no enteral or organ-specific adverse events to TLf. There were 2 deaths in the TLf group (1 each due to posterior fossa hemorrhage and postdischarge sudden infant death), and 1 death in the placebo group, due to NEC. The rate of hospital-acquired infections was 50% lower in the TLf group compared with the placebo group (P < .04), including fewer blood or line infections, urinary tract infections, and pneumonia. Fourteen infants in the TLf group weighing <1 kg at birth had no gram-negative infections, compared with only 3 of 14 such infants in the placebo group. Noninfectious outcomes were not statistically significantly different between the 2 groups, and there were no between-group differences in growth or neurodevelopment over a 1-year posthospitalization period.. We found no clinical or laboratory toxicity and a trend toward less infectious morbidity in the infants treated with TLf.. ClinicalTrials.gov: NCT00854633.

Topics: Administration, Oral; Bacteremia; Cross Infection; Double-Blind Method; Enterocolitis, Necrotizing; Female; Follow-Up Studies; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Humans; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Lactoferrin; Male; Meningitis; Pneumonia; Protective Agents; Sepsis; Treatment Outcome; Urinary Tract Infections

Aggregatibacter actinomycetemcomitans, a periodontopathogen, has been associated with several systemic diseases. Herein, we report the protective effect of human lactoferrin (hLF) during A. actinomycetemcomitans bacteremia in lactoferrin knockout (LFKO(-/-)) mice. The prophylactic, concurrent, and therapeutic intravenous (i.v.) administrations of hLF significantly cleared the bacteria from blood and organs. Nevertheless, all modes of hLF administration significantly decreased the concentrations of serum proinflammatory cytokines, such as interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), IL-6, IL-10, and IL-12p70. Additionally, hLF administration significantly decreased hepatic and splenic proinflammatory cytokine expression levels compared to those in the non-hLF-treated group. Furthermore, administration of hLF decreased the serum C-reactive protein level, inducible nitric oxide synthase (iNOS) and myeloperoxidase (MPO) gene expression levels in liver and spleen. hLF treatment has also resulted in a 6-fold decrease in spleen weight with the migration of typical inflammatory cells in infected mice as a result of decreased inflammatory response. These results reveal that hLF protects against A. actinomycetemcomitans bacteremia, as indicated by rapid bacterial clearance and decreased host proinflammatory mediators.

Topics: Aged, 80 and over; Aggregatibacter actinomycetemcomitans; Animals; Bacteremia; C-Reactive Protein; Humans; Interferon-gamma; Interleukin-10; Interleukin-12; Interleukin-1beta; Interleukin-6; Lactoferrin; Male; Mice, Knockout; Nitric Oxide Synthase Type II; Tumor Necrosis Factor-alpha

Streptococcus mutans is the primary agent of dental caries, which is often detected in transient bacteremia. Lactoferrin is a multifunctional glycoprotein showing antibacterial activities against several Streptococcus species. We reported here the prophylactic effect of human lactoferrin (hLF) in a lactoferrin knockout mouse (LFKO-/-) bacteremic model. The hLF treatment significantly cleared S. mutans from the blood and organs of bacteremic mice when compared to the non-hLF treated mice. Further, analysis of serum cytokines, spleen and liver cytokine mRNA levels revealed that hLF prophylaxis modulates their release differently when compared to the non-hLF treated group. C-reactive protein level (P = 0.003) also decreased following hLF prophylaxis in S. mutans induced bacteremic mice. Additional quantitative RT-PCR analysis revealed that hLF prophylaxis significantly decreased the expression level of IFN-γ, TNF-α, IL-1β, IL-6, MPO and iNOS in spleen and liver. These results suggested that the hLF protects the host against S. mutans-induced experimental bacteremia.

Topics: Animals; Anti-Bacterial Agents; Bacteremia; C-Reactive Protein; Granulocyte Colony-Stimulating Factor; Humans; Interferon-gamma; Interleukin-1beta; Interleukin-3; Interleukin-6; Lactoferrin; Liver; Male; Mice; Mice, Knockout; Nitric Oxide Synthase Type II; Recombinant Fusion Proteins; Spleen; Streptococcal Infections; Streptococcus mutans; Tumor Necrosis Factor-alpha

Mice orally infected with enterohaemorrhagic Escherichia coli (EHEC) O157:H7 were used to evaluate the activity of bovine lactoferrin (bLF) and the synthetic peptide LFchimera. Groups of BALB/c mice inoculated intragastrically with EHEC O157:H7 showed chronic intestinal infection with the pathogen that persisted over 6 days and resulted in a high mortality rate (90%). LFchimera and kanamycin significantly decreased (40%) this mortality rate (P = 0.028). On the other hand, although mice administered with bLF showed an important reduction in mortality (50%), this was not statistically significant (P = 0.070). In infected and untreated mice, severe tubular necrosis, glomerular lesions, and moderate intratubular hyaline casts were found in the kidney. However, in the bLF and LFchimera groups we found a reduction in the damage and a substantial decrease in the bacterial concentration excreted in feces 48 h after infection. Furthermore, sepsis caused by EHEC was reduced by the treatments, evidenced by the fact that bacteria were not detected in the kidney or liver 72 h after infection. The results suggest the bLF and LFchimera could have potential as therapeutics in EHEC infections.

Topics: Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Bacteremia; Cattle; Drug Therapy, Combination; Escherichia coli Infections; Escherichia coli O157; Feces; Intestines; Kanamycin; Kidney; Lactoferrin; Liver; Male; Mice; Mice, Inbred BALB C

Nosocomial infection with antibiotic-resistant strains is a major threat to critical care medicine. Selective decontamination of the digestive tract (SDD) is one of the strategies used to reduce ventilator-associated pneumonia and sepsis in critically ill patients. In the present study, we performed pathogenic challenges of the digestive tract in a transgenic milk-fed animal model to test whether porcine lactoferrin (pLF) is an effective SDD regimen.. Transgenic mice expressing recombinant pLF in their milk at a mean+/-SD concentration of 120+/-13.6 mg/L during the lactation stage fed normal CD-1 mice pups for 4 weeks. The pups were subsequently challenged with pathogenic Escherichia coli, Staphylococcus aureus, and Candida albicans.. Compared with the control groups fed wild-type (normal) milk, the groups fed pLF-enriched milk demonstrated statistically significant improvements in weight gain; lower bacterial numbers in intestinal fluid, blood, and liver; healthier microvilli in the small intestine; and alveoli in the lungs.. Our results showed that oral administration of pLF-enriched milk to mice led to broad-spectrum antimicrobial activity in the digestive tract and protected the mucosa of the small intestine from injury, implying that pLF can be used as an effective SDD regimen.

Topics: Animals; Animals, Newborn; Bacteremia; Bacterial Infections; Body Weight; Candidiasis; Cytokines; Escherichia coli Infections; Gastrointestinal Tract; Immunohistochemistry; Intestines; Lactation; Lactoferrin; Lung; Mice; Mice, Transgenic; Milk; Polymerase Chain Reaction; Recombinant Proteins; Staphylococcal Infections; Swine

The role of bovine serum or plasma proteins in Haemophilus somnus virulence was investigated in a mouse model of septicemia. An increase in virulence was detected when the organism was pre-incubated for 5 min and inoculated with fetal calf serum. When purified bovine serum or plasma proteins were pre-incubated with H. somnus before inoculating into mice, transferrin was found to increase virulence. Bovine lactoferrin was also noted to increase virulence, but to a lesser extent and had a delayed time course when compared with transferrin. Using an ELISA assay, an increased amount of H. somnus whole cells and culture supernatant bound to bovine transferrin when the organism was grown in iron-restricted media. Lactoferrin also bound to H. somnus, but binding was not affected by growth in iron-restricted media and it was eliminated with 2M NaCl, which reversed charge mediated binding. Transferrin, but not lactoferrin, supported growth of H. somnus on iron-depleted agar based media using a disk assay. Therefore, lactoferrin increased virulence by an undetermined mechanism whereas transferrin increased virulence of H. somnus by binding to iron-regulated outer-membrane proteins (IROMPs) and providing iron to the pathogen.

Topics: Animals; Bacteremia; Cattle; Culture Media; Female; Haemophilus Infections; Haemophilus somnus; Iron; Lactoferrin; Mice; Mice, Inbred Strains; Protein Binding; Transferrin; Virulence

Previous studies demonstrated that lactoferrin (LF), given intravenously (i.v.), 24 h before lethal Escherichia coli ( E. coli) infection, protects mice against mortality. The aim of this investigation was to determine whether downregulation of serum TNF alpha activity and increase of neutrophil number in the circulation and bone marrow by LF could contribute to the protective action of LF against E. coli-induced sepsis.. CBA female mice, 10-12 week old, weight 20-22 g, were used.. Mice were given 10 mg LF i.v. either 2 h or 24 h before i.v. administration of lethal dose of E. coli (5 x 10(8)).. Serum activities of TNF alpha and IL-1 were determined by bioassays 2 h following E. coli or LF injection. The blood and bone marrow smears were stained with Giemsa and May-Grünwald reagents and reviewed histologically.. LF given 24 h before E. coli caused a 60% reduction of TNF alpha released into circulation. However, pretreatment of mice with LF 2 h before bacterial challenge resulted in strong (15 fold) increase of TNF alpha serum level. Analysis of bone marrow cell composition revealed a significant increase in neutrophil lineage cell content (myelocytes, bands and mature neutrophils) following 24 h pretreatment with LF (51.8% of the total cell count), versus PBS control (32.7%) and 2 h LF pretreatment (35.8%). The percentage of neutrophils (bands and mature forms) in the peripheral blood rose to 47.4% versus 32% and 32%, respectively. Intravenous administration of LF increased also interleukin 1 (IL-1) concentration in the circulation of noninfected mice.. This investigation has added more information regarding the mechanism of the protective action of LF in E. coli-induced bacteremia by revealing the phenomenon of accelerated neutrophil recruitment and down-regulation of E. coli-induced TNF alpha serum level.

Topics: Animals; Bacteremia; Bone Marrow; Dose-Response Relationship, Drug; Escherichia coli; Escherichia coli Infections; Female; Interleukin-1; Lactoferrin; Mice; Mice, Inbred CBA; Neutrophils; Sepsis; Time Factors; Tumor Necrosis Factor-alpha

Pneumococcal surface protein A (PspA), a virulence factor of Streptococcus pneumoniae, is exceptionally diverse, being classified into two major families which are over 50% divergent by sequence analysis. A family 1 PspA from strain WU2 was previously shown to impede the clearance of pneumococci from mouse blood and to interfere with complement deposition on the bacterial surface. To determine whether a family 2 PspA can perform the same role as family 1 PspA, the family 1 PspA (from strain WU2) was replaced with a family 2 PspA (from strain TIGR4) by molecular genetic methods to make an isogenic pair of strains expressing different PspA proteins. Surface binding of lactoferrin and interference with C3 deposition by the two types of PspA proteins were determined by flow cytometry, and virulence was assessed in a mouse bacteremia model. Although the family 2 PspA appeared to bind less human lactoferrin than did the family 1 PspA, both PspA proteins could interfere with complement deposition on the pneumococcal surface and could provide full virulence in the mouse infection model. A mutant form of the family 2 PspA with a deletion within the choline-binding region was also produced. Pneumococci with this mutant PspA failed to bind human lactoferrin even though the PspA was present on the pneumococcal surface. The mutant PspA only partially interfered with complement deposition and moderately attenuated virulence. These results suggest that family 1 and family 2 PspA proteins play similar roles in virulence and that surface accessibility of PspA is important for their function.

Topics: Amino Acid Sequence; Animals; Antigens, Bacterial; Antigens, Surface; Bacteremia; Bacterial Proteins; Complement Activation; Complement C3; Disease Models, Animal; Female; Humans; Lactoferrin; Mice; Mice, Inbred CBA; Molecular Sequence Data; Mutation; Pneumococcal Infections; Sequence Analysis, DNA; Streptococcus pneumoniae; Virulence

Fever suggests the likelihood of severe microbial infection. Abnormal temperature, tachycardia, tachypnea, and abnormal white blood cell counts define the systemic inflammatory response syndrome (SIRS). In 300 hospitalized medical patients with fever, we determined clinical variables and procalcitonin, elastase-alpha1-antitrypsin, and lactoferrin levels in plasma. Of the patients, 71% had clinical infection (by clinical judgment) and 44% had microbial infection (by microbiological testing). SIRS occurred in 95%, and the 28-day mortality rate was 9%. The sensitivity for predicting microbial infection, bacteremia, and mortality was less but the specificity was greater for supranormal procalcitonin, elastase-alpha1-antitrypsin, and lactoferrin levels than for SIRS. The area under the receiver operating characteristic curve (AUC) for microbial infection was higher for procalcitonin and elastase-alpha1-antitrypsin levels than for clinical variables and lactoferrin level. The AUC for bacteremia was also higher for inflammatory factors (>0.70; P < .001) than for clinical variables. The AUC for mortality (P < .05) was 0.79 for the respiratory rate, 0.69 for elastase-alpha1-antitrypsin level, 0.65 for heart rate, 0.61 for procalcitonin level, and 0.60 for white blood cell count. In febrile medical patients, plasma procalcitonin and elastase-alpha1-antitrypsin levels may predict microbial infection and bacteremia better than (and mortality as well as) do clinical symptoms.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; alpha 1-Antitrypsin; Bacteremia; Bacterial Infections; Calcitonin; Calcitonin Gene-Related Peptide; Female; Fever; Humans; Lactoferrin; Leukocyte Elastase; Male; Middle Aged; Predictive Value of Tests; Prognosis; Protein Precursors

To investigate interactions between the endothelium and leukocytes in patients with sepsis, we measured soluble adhesion molecules (sE-selectin and sICAM-1), von Willebrand factor antigen (vWf:Ag), myeloperoxidase (MPO), and lactoferrin (Lacto-f) as plasma markers of endothelial and neutrophil activation. We tested whether the five proteins were predictors of clinical severity, which was evaluated by simplified acute physiological score (SAPS), number of organ failures (MOF), acute lung injury (ALI), and subsequent final outcome. Levels of the five plasma markers were higher in patients with severe infection (n = 25) than in patients without sepsis (n = 7) and healthy volunteers (n = 9). In the study population, levels of sE-selectin, sICAM-1, and vWf:Ag were higher for nonsurvivors as well as for patients with septic shock or with bacteremia, and they were correlated with SAPS and MOF. Survival outcome was predicted with high sensitivity and specificity by initial plasma levels of sICAM-1 and vWf:Ag. The initial sICAM-1 level appeared to be an independent prognostic variable, based on a logistic regression analysis. Unlike sE-selectin, sICAM-1 remained at high levels indefinitely in nonsurvivors. We conclude that, unlike neutrophil activation markers, levels of endothelium-derived soluble adhesion molecules and vWf:Ag in severe sepsis syndrome are correlated with the severity of illness and may be considered as predictors of survival outcome.

Topics: Adult; Aged; Aged, 80 and over; APACHE; Bacteremia; Biomarkers; E-Selectin; Endothelium, Vascular; Female; Follow-Up Studies; Forecasting; Humans; Intercellular Adhesion Molecule-1; Lactoferrin; Leukocytes; Logistic Models; Male; Middle Aged; Multiple Organ Failure; Neutrophil Activation; Peroxidase; Prognosis; Sensitivity and Specificity; Sepsis; Shock, Septic; Survival Rate; Treatment Outcome; von Willebrand Factor

In a prospective study of 65 patients with S. aureus septicemia, the clinical value of measuring serum IL-6 and lactoferrin levels was assessed and compared with CRP levels and WBC count. 20/65 (31%) patients had a CRP value < or = 100 mg/l on admission and 10 (50%) and 11 (55%) of these had serum levels of IL-6 > 100 pg/ml or lactoferrin > 2.0 mg/l, respectively. 41/64 (64%) patients had a WBC count < or = 15.0 x 10(9)/l and the corresponding figures for increased IL-6 and lactoferrin values were 29 (71%) and 21 (51%) patients, respectively. The high concentrations of IL-6 and lactoferrin on admission decreased rapidly during the hospital stay, better reflecting the clinical course than CRP and WBC count. Patients with endocarditis showed higher IL-6 levels and body temperatures both on admission and during the first days of hospitalization compared with patients without endocarditis.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bacteremia; Biomarkers; Blood Sedimentation; C-Reactive Protein; Child; Enzyme-Linked Immunosorbent Assay; Female; Humans; Interleukin-6; Lactoferrin; Leukocyte Count; Male; Middle Aged; Prospective Studies; Sensitivity and Specificity; Staphylococcal Infections

Because of its neutrophil-activating properties, interleukin-8 (IL-8) may play an important role in the pathophysiology of sepsis. We measured circulating IL-8 levels in 47 patients with clinical sepsis. Levels on admission were elevated in 42 of the 47 patients (89%) and were comparable in patients with gram-positive or gram-negative infections. Patients with shock had significantly higher IL-8 levels than normotensive patients (P = 0.0014, Wilcoxon-Mann-Whitney test), whereas no differences in IL-8 levels were found between patients with or without adult respiratory distress syndrome. Patients who died had higher IL-8 levels on admission than the patients who survived. The largest differences in IL-8 levels between survivors and nonsurvivors was found when only patients with positive cultures were considered (P = 0.0342). IL-8 levels appeared to correlate significantly with lactate levels and inversely with leukocyte and platelet numbers and mean arterial pressure. In addition, the IL-8 level in the sepsis patients was found to correlate significantly with levels of IL-6, elastase-alpha 1-antitrypsin, and C3a. Serial observations revealed that in most patients IL-8 levels decreased, irrespective of the outcome. Thus, our results demonstrate that IL-8 levels are increased in most patients with sepsis and correlate with some important clinical, biochemical, and inflammatory parameters. These findings suggest a role for IL-8 in the pathophysiology of sepsis.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; alpha 1-Antitrypsin; Bacteremia; Blood Pressure; Complement C3a; Enzyme-Linked Immunosorbent Assay; Factor XII; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Humans; Interleukin-6; Interleukin-8; Lactates; Lactic Acid; Lactoferrin; Leukocyte Elastase; Middle Aged; Pancreatic Elastase; Prekallikrein; Respiratory Distress Syndrome; Shock, Septic