Mimicking Nonribosomal Peptides from the Marine Actinomycete Streptomyces sp. H-KF8 Leads to Antimicrobial Peptides.

Microorganisms within the marine environment have been shown to be very effective sources of naturally produced antimicrobial peptides (AMPs). Several nonribosomal peptides were identified based on genome mining predictions of Streptomyces sp. H-KF8, a marine Actinomycetota isolated from a remote Northern Chilean Patagonian fjord. Based on these predictions, a series of eight peptides, including cyclic peptides, were designed and chemically synthesized. Six of these peptides showed antimicrobial activity. Mode of action studies suggest that two of these peptides potentially act on the cell membrane via a novel mechanism allowing the passage of small ions, resulting in the dissipation of the membrane potential. This study shows that though structurally similar peptides, determined by NMR spectroscopy, the incorporation of small sequence mutations results in a dramatic influence on their bioactivity including mode of action. The qualified hit sequence can serve as a basis for more potent AMPs in future studies.

Significant and rapid reduction of free endotoxin using a dialkylcarbamoyl chloride-coated wound dressing.

OBJECTIVE: Endotoxin causes inflammation and can impair wound healing. Conventional methods that reduce bioburden in wounds by killing microorganisms using antibiotics, topical antimicrobials or antimicrobial dressings may induce endotoxin release from Gram-negative bacteria. Another approach is to reduce bioburden by adsorbing microorganisms, without killing them, using dialkylcarbamoyl chloride (DACC)-coated wound dressings. This study evaluated the endotoxin-binding ability of a DACC-coated wound dressing (Sorbact Compress, Abigo Medical AB, Sweden) in vitro, including its effect on the level of natural endotoxin released from Gram-negative bacteria. METHOD: Different concentrations of purified Pseudomonas aeruginosa endotoxin and a DACC-coated dressing were incubated at 37°C for various durations. After incubation, the dressing was removed and endotoxin concentration in the solution was quantified using a Limulus amebocyte lysate (LAL) assay. The DACC-coated dressing was also incubated with Pseudomonas aeruginosa cells for one hour at 37°C. After incubation, the dressing and bacterial cells were removed and shed endotoxin remaining in the solution was quantified. RESULTS: Overnight incubation of the DACC-coated wound dressing with various concentrations of purified Pseudomonas aeruginosa endotoxin (96-11000 EU/ml) consistently and significantly reduced levels of free endotoxin by 93-99% (p<0.0001). A significant endotoxin reduction of 39% (p<0.001) was observed after five minutes. The DACC-coated dressing incubated with clinically relevant Pseudomonas aeruginosa cells also reduced shed endotoxin by >99.95% (p<0.0001). CONCLUSION: In this study, we showed that a DACC-coated wound dressing efficiently and rapidly binds both purified and shed endotoxin from Pseudomonas aeruginosa in vitro. This ability to remove both endotoxin and bacterial cells could promote the wound healing process.

Endotoxin in Aerosol Particles from Metalworking Fluids Measured with a Sioutas Cascade Impactor.

OBJECTIVES: The aim of this study was to characterize personal occupational exposure to endotoxin in size-separated airborne particles of MWF aerosol, using a Sioutas cascade impactor (SCI). METHODS: Exposure to inhalable fractions of MWF aerosol and endotoxin was measured by personal sampling of 52 individuals over an 8-h work shift using a PAS-6 sampler in parallel with a SCI (<0.25, 0.25-0.5, 0.5-1.0, 1.0-2.5, and 2.5-10 µm). Aerosol mass concentration was measured for each worker with a real-time instrument (DataRAM) during a full shift. Samples of MWF were collected from the machines and central tanks during the work shift. RESULTS: A total of 117 measurements of inhalable MWF aerosols were made among 52 workers. The geometric mean of inhalable MWF aerosol was 0.16 mg m-3 air. The geometric mean of endotoxin concentration on the inhalable sampler was 0.15 EU m-3. Airborne endotoxin was found on all size fractions from the impactor, with the major part seen in the fraction (2.5-10 µm). There was a correlation between the inhalable fraction of endotoxin measured by the PAS-6 sampler and on the SCI sampler (2.5-10 µm), estimated to be 0.51 for all samples (P < 0.0001). The concentration of endotoxin varied between the MWFs, as did the proportion of Gram-negative bacteria among the culturable bacteria (>80% in one MWF and <1.5% in the other three). CONCLUSIONS: The personal exposure to inhalable fractions of endotoxin contained in the MWF aerosol were low, where most of the endotoxin were found in fraction (2.5-10 µm), measured by SCI. There are differences between factories and MWF systems regarding the distribution of endotoxin and so results from one context should not be generalized to other plants and systems. Compressed air was used for less than 10 min shift-1. The mixed-effect model showed that working with open machines and grinding as cutting task were important determinants of exposure to inhalable aerosol. It is important to keep occupational exposure to aerosols low with the help of good ventilation systems, enclosed machines, and organization of work.

Endotoxin in Size-Separated Metal Working Fluid Aerosol Particles.

Patients with airway symptoms working in metal working industries are increasing, despite efforts to improve the environmental air surrounding the machines. Our aim was to analyse the amount of endotoxin in size-separated airborne particles of metal working fluid (MWF) aerosol, by using the personal sampler Sioutas cascade impactor, to compare filter types, and to compare the concentration of airborne endotoxin to that of the corresponding MWFs. In a pilot field study, aerosols were collected in two separate machine halls on totally 10 occasions, using glass fibre and polytetrafluoroethylene (PTFE) filters in parallel at each station. Airborne endotoxin was distributed over all size fractions. While a major part was found in the largest size fraction (72%, 2.5-10 µm), up to 8% of the airborne endotoxin was detected in the smallest size fraction (<0.25 µm). Comparing the efficiency of the filter types, a significantly higher median endotoxin level was found with glass fibres filters collecting the largest particle-size fraction (1.2-fold) and with PTFE filters collecting the smallest ones (5-fold). The levels of endotoxin in the size-separated airborne particle fractions correlated to those of the MWFs supporting the aerosol-generating machines. Our study indicates that a significant part of inhalable aerosols of MWFs consists of endotoxin-containing particles below the size of intact bacteria, and thus small enough to readily reach the deepest part of the lung. Combined with other chemical irritants of the MWF, exposure to MWF aerosols containing endotoxin pose a risk to respiratory health problems.

Anti-infective efficacy of the lactoferrin-derived antimicrobial peptide HLR1r.

Antimicrobial peptides (AMPs) have emerged as a new class of drug candidates for the treatment of infectious diseases. Here we describe a novel AMP, HLR1r, which is structurally derived from the human milk protein lactoferrin and demonstrates a broad spectrum microbicidal action in vitro. The minimum concentration of HLR1r needed for killing ≥99% of microorganisms in vitro, was in the range of 3-50µg/ml for common Gram-negative and Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), and for the yeast Candida albicans, when assessed in diluted brain-heart infusion medium. We found that HLR1r also possesses anti-inflammatory properties as evidenced by inhibition of tumor necrosis factor alpha (TNF-α) secretion from human monocyte-derived macrophages and by repression of interleukin-6 (IL-6) and plasminogen activator inhibitor-1 (PAI-1) secretion from human mesothelial cells, without any cytotoxic effect observed at the concentration range tested (up to 400µg/ml). HLR1r demonstrated pronounced anti-infectious effect in in vivo experimental models of cutaneous candidiasis in mice and of excision wounds infected with MRSA in rats as well as in an ex vivo model of pig skin infected with S. aureus. In conclusion, HLR1r may constitute a new therapeutic alternative for local treatment of skin infections.

Dysfunction of Circulating Polymorphonuclear Leukocytes and Monocytes in Ambulatory Cirrhotics Predicts Patient Outcome.

BACKGROUND: Cirrhosis represents a state of functional immune paresis with increased infection risk. AIMS: To investigate polymorphonuclear (PMN) leukocyte and monocyte function in ambulatory cirrhotics, and their potential relation with cirrhosis etiology or patient outcome. METHODS: Consecutive ambulatory cirrhotics without current or recent (<1 month) infection or acute decompensation were prospectively enrolled in 2013 and followed for a median time of 20 months until death, transplant or end of 2014. Oxidative burst and phagocytosis of circulating PMNs and monocytes were investigated at baseline and after in vitro Escherichia coli stimulation. Seventeen healthy blood donors served as controls. Baseline clinical and laboratory data as well as follow-up data on the development of cirrhosis complications, including acute-on-chronic liver failure (ACLF), and bacterial infections were collected. RESULTS: Sixty patients were included (70 % male, median age 63 years, 52 % with alcoholic cirrhosis). Compared to controls, cirrhotics showed increased resting and stimulated burst as well as reduced phagocytosis of PMNs, and increased stimulated monocyte burst (p < 0.05 for all). Alcoholic etiology was not related to PMN or monocyte dysfunction (p > 0.05 for all). In Cox regression analysis, increased stimulated monocyte and PMN burst were independent predictors of sepsis, severe sepsis and ACLF occurrence. Also, increased stimulated monocyte burst was associated with worse transplant-free survival (p < 0.05 for all). CONCLUSIONS: Stimulated PMN and monocyte oxidative burst are increased in ambulatory cirrhotics without acute decompensation. In turn, these changes are associated to sepsis and ACLF occurrence.

IgG1 anti-cell wall and IgG2 anti-phosphopeptidomannan antibodies in the diagnosis of invasive candidiasis and heavy Candida colonization.

We conducted a retrospective study to evaluate the usefulness of immunoglobulin G (IgG) subclasses against Candida cell wall fragments (CW) and phosphopeptidomannan (PPM) for the diagnosis of invasive candidiasis (IC). We analyzed 54 patients with IC (n = 19), Candida heavy colonization (HC; n = 16), and controls (no IC or HC, n = 19).In nonneutropenic patients (n = 47), the sensitivity and specificity values of IgG1 anti-CW and IgG2 anti-PPM in IC were 88%, 59%, and 88%, 94%, respectively. The areas under the receiver operating characteristic curves were 0.69 (0.51-0.88) and 0.901 (0.78-1.02), respectively. IgG1 mean values (arbitrary units) and 95% confidence interval were 46 (20-71), 42 (-0.38 to 84) and 20 (8.3-32) in IC, HC, and in controls, respectively, and discriminated IC but not HC from controls (P = .032, and P = .77, respectively). IgG2 mean values were 26 (9.2-42), 19 (4.4-33), and 3.2 (0.28-6.6) in IC, HC, and in controls, respectively, and discriminated both IC and HC from controls (P < .0001 and P = .035, respectively) but did not separate IC from HC (P = .2). IgG2 showed positivity as early as one day after the IC diagnosis. Antibodies were detected in only two out of a total of seven neutropenic patients.For both IC and HC patients, the diagnostic performance of IgG2 anti-PPM was better than the one of IgG1 anti-CW. In nonneutropenic patients, IgG2 anti-PPM accurately identified not only IC patients but also HC patients at high risk for IC. This marker may help clinicians in the initiation of early preemptive therapy.

Endocytosis and trafficking of human lactoferrin in macrophage-like human THP-1 cells (1).

Different cell types have been reported to internalize lactoferrin (Lf) by specific or nonspecific receptors. Our studies focused on the endocytic pathway of human Lf in macrophage-like THP-1 cells. Lactoferrin was found to be internalized by THP-1 cells differentiated with phorbol myristate acetate. Incubation of cells with chlorpromazine and dansylcadaverine, inhibitors of clathrin-dependent endocytosis, led to a 50% inhibition of Lf internalization compared with untreated cells. Bafilomycin A1 and NH(4)Cl treatment also resulted in 40%-60% inhibition, respectively, suggesting that the internalization of Lf may partly be mediated by acidic endosome-like organelles. Endocytic uptake of Lf was also cholesterol-dependent, as shown by methyl-ß-cyclodextrin or nystatin treatment of the cells prior to internalization. Partial colocalization of Lf and EEA-1, a marker specific for early endosomes, could be observed. Colocalization of Lf with a specific endoplasmic reticulum marker was also detected. Our results suggest that Lf is internalized mainly by the clathrin-dependent pathway in THP-1 cells and targets the ER. The physiological consequences of this intracellular trafficking will be the subject of future investigations.

Affinity apheresis for treatment of bacteremia caused by Staphylococcus aureus and/or methicillin-resistant S. aureus (MRSA).

Staphylococcus aureus (SA) bacteremia is associated with high mortality, and often results in metastatic infections. The methicillin-resistant SA (MRSA) is an urgent health care issue, as nosocomial infections with these bacteria represent limited treatment alternatives. Samples of whole blood containing challenge inoculums of SA and MRSA strains were passed through columns packed with surface-heparinized polyethylene beads. The bound bacteria were eluted and quantitatively determined by culturing and by real-time PCR. Significant amounts of both SA and MRSA adhered to the heparinized beads (more than 65% of inoculated bacteria). After rinsing with buffer at high ionic strength, viable bacteria or bacterial DNA were eluted from the columns, indicating that the binding was specific. The conclusions that can be made from these experiments are that, as earlier reported in the literature, the high affinity of SA to heparin is retained in whole blood, and MRSA in whole blood binds to heparin with similar or higher affinity than SA. It should be possible to lower the amount of SA and/or MRSA from the blood of infected patients to levels that could be taken care of by the immune system. In previous studies, we have shown that passing blood from septic patients over beads coated with end-point-attached, biologically active heparin is a useful technique for regulating the levels of heparin-binding cytokine. These findings in combination with the present findings indicate the possibility of creating an apheresis technology for treatment of sepsis caused by SA and/or MRSA.

A novel polypeptide derived from human lactoferrin in sodium hyaluronate prevents postsurgical adhesion formation in the rat.

OBJECTIVE: The objective of the study was to evaluate whether a peptide derived from human lactoferrin, PXL01 could act safely to reduce the formation of peritoneal adhesions in the rat model and to map the molecular mechanisms of its action. SUMMARY BACKGROUND DATA: Adhesion formation is a significant problem within every surgical discipline causing suffering for the patients and major cost for the society. For many decades, attempts have been made to reduce postsurgical adhesions by reducing surgical trauma. It is now believed that major improvements in adhesion prevention will only be reached by developing dedicated antiscarring products, which are administrated in connection to the surgical intervention. METHODS: Anti-inflammatory as well as fibrinolytic activities of PXL01 were studied in relevant human cell lines. Using the sidewall defect-cecum abrasion model in the rat, the adhesion prevention properties of PXL01 formulated in sodium hyaluronate were evaluated. Large bowel anastomosis healing model in the rat was applied to study if PXL01 would have any negative effects on intestine healing. RESULTS: PXL01 exhibits an inhibitory effect on the most important hallmarks of scar formation by reducing infections, prohibiting inflammation, and promoting fibrinolysis. PXL01 formulated in sodium hyaluronate markedly reduced formation of peritoneal adhesions in rat without any adverse effects on wound healing. CONCLUSIONS: A new class of synthetically derived water soluble low molecular weight peptide compound, PXL01 showed marked reduction of peritoneal adhesion formation in an animal model without any negative effects on healing. On the basis of these data, a comprehensive adhesion prevention regimen in clinical situation is expected.

Reduced liver injury and cytokine release after transplantation of preconditioned intestines.

BACKGROUND: The postischemic intestine liberates pro-inflammatory mediators (cytokines, lipopolysaccharide [LPS], free radicals) proportional with the local injury that may trigger a systemic inflammatory response and multi-system organ failure. Previously, intestines from donors receiving Tacrolimus revealed improved morphology and abrogated nuclear factor kappa B (NF-kappaB) activation. Because of its pivotal role in inflammation, we investigated if NF-kappaB intragraft inhibition influences the posttransplant inflammatory response and remote organ injury. MATERIALS AND METHODS: Donor Sprague Dawley rats received tacrolimus (0.3 mg/kg) or saline i.v. 6 h before graft harvest. The intestines were preserved for 3 h and then transplanted heterotopically. Hepatic microcirculation was assessed at 20 min, 6 h, 12 h, or 24 h post-reperfusion (postR) using laser-Doppler flowmetry (n = 10/group). Blood pressure measurements and liver sampling were performed at 6, 12, or 24 h postR. Blood samples were obtained at 1, 3, 6, 12, and 24 h postR. Hepatic intercellular adhesion molecule 1 (ICAM-1) expression, caspase-3 and -9 activity, and circulating tumor necrosis factor alpha (TNF-alpha), interleukin-1beta (IL-1beta), IL-6, and LPS were studied. RESULTS: Pretreated graft (PG) recipients had superior cardiovascular parameters at 6 and 12 h postR, while liver perfusion was similar between groups at all time points. Recipients of PG had lower transaminase levels and ICAM-1 liver expression. Liver caspase 3 and 9 activity were similar at 6 and 12 h but increased at 24 h in both groups. At every time point, circulating tumor necrosis factor alph, IL-1beta, and IL-6 were lower in animals receiving PG. LPS was found increased only at the last time point. CONCLUSIONS: Transplantation of tacrolimus-pretreated intestines triggered a milder inflammatory response and decreased liver injury early posttransplantation compared with untreated grafts. Cytokines, but not neutrophils, hypoperfusion, or LPS may underlie the dysfunction.

The lower genital tract microbiota in relation to cytokine-, SLPI- and endotoxin levels: application of checkerboard DNA-DNA hybridization (CDH).

In the present study the lower genital tract microbiota in asymptomatic fertile women (n=34) was identified and quantified by culturing vaginal secretions. Also, vaginal and cervical samples were analyzed by a semiquantitative checkerboard DNA-DNA hybridization technique (CDH) based on genomic probes prepared from 13 bacterial species (Bacteroides ureolyticus, Escherichia coli, Fusobacterium nucleatum, Gardnerella vaginalis, Mobiluncus curtisii ss curtisii, Prevotella bivia, Prevotella disiens, Prevotella melaninogenica, Atopobium vaginae, Lactobacillus iners, Staphylococcus aureus ss aureus, Streptococcus anginosus, and Streptococcus agalactiae). The bacterial species found by either culture or CDH were correlated with proinflammatory cytokines (IL-1 alpha, IL-1 beta, IL-6, IL-8), secretory leukocyte protease inhibitor (SLPI), and endotoxin in the cervicovaginal samples. Grading the women into healthy, intermediate, or bacterial vaginosis (BV) as based on Gram staining of vaginal smears, the viable counts of lactobacilli (L. gasseri) and of streptococci-staphylococci combined were highest in the intermediate group. In BV, particularly the high concentrations of Actinomyces urogenitalis, Atopobium vaginae, and Peptoniphilus harei were noted (>or=10(11) per ml). The total viable counts correlated with both cervical IL-1 alpha and IL-1 beta. A strong negative correlation was observed between L. iners and total viable counts, G. vaginalis, or cervical IL-1 alpha, while it correlated positively with SLPI. Analysis of vaginal and cervical samples from 26 out of the 34 women by CDH showed that anaerobic bacteria were more frequently detected by CDH compared to culture. By this method, A. vaginae correlated with G. vaginalis, and L. iners with S. aureus. With regard to cytokines, B. ureolyticus correlated with both cervical and vaginal IL-1 alpha as well as with cervical IL-8, while F. nucleatum, S. agalactiae, S. anginosus, or S. aureus correlated with vaginal IL-1 alpha. Furthermore, all Gram-negative bacteria taken together, as measured by CDH, correlated with vaginal endotoxin and inversely with vaginal SLPI. The significance of the results is discussed. In summary, mapping of the identity and quantity of vaginal bacterial species and their association with locally produced host innate immune factors will help in defining various types of abnormal vaginal microbiota, developing new ways of assessing the risk of ascending subclinical infections, and in treating them. CDH appears to be a suitable tool for future analyses of large numbers of clinical samples with an extended number of bacterial probes.

Growth and nutrition: the first six months.

Today the WHO Growth Chart Standards, based on the growth of breastfed infants, are used. These growth curves solve the problem of the deviating observations for breastfed compared to non-breastfed infants using previous growth charts. Presently it is not clear how the mother's diet, especially the fat intake, influences the growth of the offspring. Animal experiments indicate that a low intake of n-3 polyunsaturated fatty acids via the milk may have short- and long-term negative consequences. There is limited information in man. It has been suggested that the mammary glands may have phylogenetically originated from glands providing innate immunity, later developing capacities for providing nutrition. This would agree with the fact that human milk contains so many major components which do not primarily function as nutrients, but seem to protect nutrition and growth. Lactoferrin, oligosaccharides, glycoproteins, secretory IgA antibodies, alpha-lactalbumin and the antisecretory factor have such functions.

Prevotella bivia can invade human cervix epithelial (HeLa) cells.

Prevotella bivia has been associated with female upper genital tract infections and an increased risk of preterm delivery. In this study, the adherence and invasion capacity of P. bivia was investigated using a cervix epithelial cell line. P. bivia was furthermore analysed for its ability to evoke a proinflammatory cytokine response in epithelial cells. The invasion capacity, defined as the number of bacteria recovered from lysed HeLa cells infected with P. bivia, varied considerably among five strains, all of which were isolates from women with bacterial vaginosis. One P. bivia strain (P47) gave rise to an approximately 120-fold higher number of intracellular bacteria (7 x 10(3) bacteria per 1 x 10(5) cells) compared with the least invasive strain. Three strains expressed an intermediate or low invasiveness, showing an approximately 3- to 40-fold higher number of intracellular bacteria per 1 x 10(5) cells compared with the least invasive strain. The intracellular localization of P47 in phagosome-like vesicles was confirmed by transmission electron microscopy. All P. bivia strains adhered to HeLa cells to the same extent (range 14-22 bacteria per cell) as analysed by interference microscopy. No correlation was found between adhesion and invasion capacity of the strains. Furthermore, no fimbriae-like structures were observed on P47 detected by scanning electron microscopy or negative staining. Analysis of TNF-alpha, IL-1alpha, IL-6, IL-8, and IL-18 in P. bivia-stimulated HeLa cells showed low levels of only IL-6 and IL-8 for the most invasive P. bivia strain P47. Thus, the induction of IL-6 or IL-8 secretion appeared to be associated with invasion capacity. This work provides evidence that some P. bivia isolates can invade human cervix epithelial. Thus, a strong capacity for invasion and a weak proinflammatory cytokine-inducing capacity in P. bivia are suggested to be virulence factors in establishing a low-grade upper genital tract infection.

Interleukin-6 and interleukin-8 in cervical and amniotic fluid: relationship to microbial invasion of the chorioamniotic membranes.

OBJECTIVE: To evaluate the levels of interleukin (IL)-6 and IL-8 in cervical and amniotic fluid in relation to the presence of bacteria in the membranes in women in preterm labour (PTL). DESIGN: A prospective follow up study. SETTING: Sahlgrenska University Hospital, Göteborg, Sweden. Sample Women with singleton pregnancies (<34 weeks) presenting with PTL (n = 30). METHODS: Amniotic fluid was retrieved transabdominally and cervical fluid was sampled from the uterine cervix at admission and analysed for IL-6 and IL-8 with enzyme-linked immunosorbent assay (ELISA). At birth, the chorioamniotic membranes were separated and samples for polymerase chain reaction (PCR) for Ureaplasma urealyticum and Mycoplasma hominis and general culture were obtained. MAIN OUTCOME MEASURE: IL-6 and IL-8 in relation to microbial invasion of the chorioamniotic membranes. RESULTS: Bacteria were found in the membranes in 8 of 21 patients in PTL for whom chorioamnion as well as amniotic fluid PCR and cultures were available. Cervical IL-6 was associated with detectable bacteria in the chorioamniotic membranes in women in PTL (median 8.2 ng/mL vs 0.73 ng/mL; P = 0.01). The IL-6 (median 13 ng/mL vs 1.7 ng/mL; P = 0.004) and IL-8 (median 7.2 ng/mL vs 0.28 ng/mL; P = 0.01) levels in amniotic fluid were higher in PTL cases in which bacteria were found in the chorioamniotic membranes. CONCLUSION: IL-6 in cervical fluid and IL-6 and IL-8 in amniotic fluid were higher in those PTL cases in which bacteria were found in the chorioamniotic membranes.

Interleukin-6 and interleukin-8 in cervical fluid in a population of Swedish women in preterm labor: relationship to microbial invasion of the amniotic fluid, intra-amniotic inflammation, and preterm delivery.

BACKGROUND: Intrauterine infection and inflammation in women with preterm labor are related to adverse perinatal outcome. Due to its subclinical nature, a correct diagnosis depends on retrieval of amniotic fluid. Amniocentesis is, however, not performed as a clinical routine because of its invasiveness. Hypothetically, cytokines in the cervical fluid may represent an alternative diagnostic approach. The aim was to examine cervical interleukin (IL)-6 and IL-8 in relation to microbial invasion of the amniotic fluid, intra-amniotic inflammation, and preterm birth in women in preterm labor. METHODS: Women with singleton pregnancies in preterm labor (<34 weeks of gestation) and intact membranes were included. Cervical (n = 91) and amniotic fluids (n = 56) were collected. Polymerase chain reaction for Ureaplasma urealyticum and Mycoplasma hominis and culture for aerobic and anaerobic bacteria were performed. IL-6 and IL-8 were analyzed with enzyme-linked immunosorbent assay. RESULTS: Non-lactobacillus-dominated biota was detected in cervical secretion in 25% (22/89) and the presence of micro-organisms in the amniotic fluid in 16% (9/56) of the patients. The presence of U. urealyticum in the cervical fluid (21/46) was associated with significantly higher levels of IL-6 in the secretion. IL-6 and IL-8 were significantly higher in cervical fluid of women with intra-amniotic infection and inflammation and in women who delivered < or =7 days and/or before 34 weeks of gestation. Cervical IL-6 > or = 1.7 ng/ml was related to intra-amniotic inflammation (relative risk: 2.67; range: 1.50-4.74) and had a sensitivity, specificity, positive predictive value, and negative predictive value of 58, 83, 75, and 69%, respectively, in the identification of intra-amniotic inflammation. Similar data were obtained for IL-8 > or = 6.7 ng/ml. CONCLUSIONS: High levels of cervical IL-6 and IL-8 are moderately predictive of intrauterine infection/inflammation and preterm delivery.

Interleukin-18 in cervical mucus and amniotic fluid: relationship to microbial invasion of the amniotic fluid, intra-amniotic inflammation and preterm delivery.

OBJECTIVE: To evaluate the relationship between interleukin (IL)-18 in cervical mucus and amniotic fluid and microbial invasion of amniotic fluid, preterm delivery and intra-amniotic inflammation in women in preterm labour, with preterm prelabour rupture of membranes and at term. DESIGN: A prospective follow up study. SETTING: Sahlgrenska University Hospital, Göteborg, Sweden. SAMPLE: Women with singleton pregnancies (<34 weeks) presenting with preterm labour (n = 87) or preterm prelabour rupture of membranes (n = 47) and women, not in labour, at term (n = 28). METHODS: Amniotic fluid was retrieved transabdominally. Cervical mucus was taken from the uterine cervix of women in preterm labour and at term. IL-18 was analysed with enzyme-linked immunosorbent assay. MAIN OUTCOME MEASURES: IL-18 in relation to microbial invasion of the amniotic fluid, delivery within seven days or <34 weeks of gestation and intra-amniotic inflammation. RESULTS: The levels of IL-18 in cervical mucus and amniotic fluid were higher in women with preterm labour than in those not in labour at term. In the preterm labour group, significant associations were found between elevated IL-18 in amniotic fluid and microbial invasion of the amniotic fluid, as well as between delivery within seven days or <34 weeks of gestation and intra-amniotic inflammation. Delivery was delayed longer in the preterm prelabour rupture of membranes subgroup with IL-18 >or=1.0 ng/mL than in that with IL-18 <1.0 ng/mL. CONCLUSIONS: In the preterm labour group, high IL-18 in amniotic fluid (but not in the cervix) was associated with microbial invasion of the amniotic fluid, intra-amniotic inflammation and prompt delivery. On the other hand, elevated IL-18 in preterm prelabour rupture of the membranes group correlated with a longer interval to delivery.

Microbial invasion and cytokine response in amniotic fluid in a Swedish population of women with preterm prelabor rupture of membranes.

BACKGROUND: Previous studies have shown an association between intra-amniotic microbial invasion and/or inflammation and spontaneous preterm birth. The aim of this study was to investigate the occurrence of intra-amniotic microorganisms and cytokines [interleukin (IL)-6 and IL-8] in a Swedish population, with low incidence of preterm birth, of women with preterm prelabor rupture of membranes and their correlation to preterm birth. METHODS: Amniotic fluid was retrieved transabdominally from 58 patients with preterm prelabor rupture of membranes before 34 weeks of gestation. Polymerase chain reaction (PCR) analyses for Ureaplasma urealyticum and Mycoplasma hominis and culture for aerobic and anaerobic bacteria were performed. IL-6 and IL-8 were analyzed with enzyme-linked immunosorbent assay (ELISA). RESULTS: Microorganisms in amniotic fluid were detected in 13 patients (25%). Patients with bacteria detected in the amniotic fluid had significantly higher levels of IL-6 and IL-8. An amniotic fluid concentration of IL-6 >/= 0.80 ng/ml [relative risk 1.93, 95% confidence interval (CI) 1.13-3.29, sensitivity 63%, specificity 75%] was associated with an increased risk of delivery within 7 days. There was also an association between IL-8 and preterm birth (< 34 weeks). CONCLUSIONS: Intra-amniotic microbial invasion and inflammation in this population of Swedish women with preterm prelabor rupture of membranes were similar to data reported from populations with a higher incidence of preterm delivery. Amniotic IL-6 correlated to the presence of microorganisms and delivery within 7 days and IL-8 to delivery before 34 weeks.

The transfer of immunity from mother to child.

The newborn's immune system grows fast from a small size at birth by exposure primarily to the intestinal microflora normally obtained from the mother at and after birth. While building up its immune system, the infant is supported by the transplacental IgG antibodies, which also contain anti-idiotypic antibodies, possibly also actively priming the offspring. The second mode of transfer of immunity occurs via the milk. Numerous major protective components, including secretory IgA (SIgA) antibodies and lactoferrin, are present. The breastfed infant is better protected against numerous common infections than the non-breastfed. Breastfeeding also seems to actively stimulate the infant's immune system by anti-idiotypes, uptake of milk lymphocytes, cytokines, etc. Therefore, the breastfed child continues to be better protected against various infections for some years. Vaccine responses are also often enhanced in breastfed infants. Long-lasting protection against certain immunological diseases such as allergies and celiac disease is also noted.