High indoor microbial levels are associated with reduced Th1 cytokine secretion capacity in infancy

Background: Exposure to microbes and their components may affect the maturation of the immune system. We examined the association of house dust microbial content with cytokine-producing capacity at birth and at the age of 1 year. Methods: Production of TNF-α, IFN-γ, IL-5, IL-8 and IL-10 at birth (n = 228) and at the age of 1 year (n = 200) following 24- and 48-hour whole-blood stimulation with staphylococcal enterotoxin B (SEB), lipopolysaccharide and the combination of phorbol ester and ionomycin was measured. Concentrations of ergosterol (marker for fungal biomass), muramic acid (marker for Gram-positive bacteria) and 3-hydroxy fatty acids with a carbon chain length from 10 to 14 (marker for Gram-negative bacteria) in living room floor dust were analyzed using gas chromatography-tandem mass spectrometry. Five single microbial species or groups were determined using a quantitative polymerase chain reaction method. Results: A high total level of the studied Gram-positive bacteria in general or Mycobacterium spp. in house dust was associated with decreased SEB-stimulated IFN-γ production, especially at the age of 1 year. The total level of indoor fungi analyzed (Penicillium spp., Aspergillus spp. and Paecilomyces variotii group, Trichoderma viride/atroviride/koningii,Wallemia sebi) was also inversely associated with IFN-γ production at the age of 1 year, but this association did not remain significant after adjustment for potential confounders. A few associations were found between microbial exposures and other measured cytokines. Conclusions: High indoor microbial exposures may affect immune development in early life by reducing T helper type 1 cytokine secretion capacity. The observed hyporesponsiveness may reflect the adaptation of the immune system to environmental antigens. In future, more attention should be paid especially to the immunomodulatory role of exposures to Gram-positive bacteria.     

Pathogenic Role of Macrophages in Intradermal Infection of Methicillin-Resistant Staphylococcus aureus in Thermally Injured Mice

Intradermal infection of methicillin-resistant Staphylococcus aureus (MRSA) in burned mice was pathogenically analyzed. An abscess was formed in normal mice intradermally infected with 10⁸ CFU/mouse of MRSA, and all of these mice survived after the infection; however, abscess formation was not demonstrated to occur in burned mice similarly exposed to the pathogen, and all of these mice died within 5 days of infection. In burned mice, MRSA infected at the burn site intradermal tissues spread quickly throughout the whole body, while in normal mice, the pathogen remained localized at the infection site. Macrophages (Mφ) isolated from the infection site tissues of normal mice produced interleukin-12 (IL-12) but not IL-10 and were characterized as M1Mφ. These M1Mφ were not isolated from the infection site tissues of burned mice. When normal-mouse infection site tissue Mφ were adoptively transferred to burned mice at the MRSA infection site, an abscess formed, and the infection did not develop into sepsis. In contrast, an abscess did not form and sepsis developed in normal mice that were inoculated with burned-mouse infection site tissue Mφ. These Mφ produced IL-10 but not IL-12 and were characterized as M2Mφ. These results indicate that abscess formation is a major mechanism of host resistance against intradermal MRSA infection. M1Mφ in the tissues surrounding the infection site play a pivotal role in abscess formation; however, the abscess is not formed in burned mice where M2Mφ predominate. M2Mφ have been described as inhibitor cells for Mφ conversion from resident Mφ to M1Mφ.Infection is the major cause of morbidity and mortality in severely burned patients (27, 33). Methicillin-resistant Staphylococcus aureus (MRSA) is known as a typical pathogen in such infections. Generally, healthy individuals are resistant against MRSA infection; however, severely burned patients with greatly suppressed immune responses are particularly susceptible to MRSA infection. In severely burned patients, MRSA was represented in 40% of the wounds, and 14% to 17% of all wounds became infected once they were colonized with MRSA (11, 14, 25). Therefore, intervention targeting the host''s antibacterial immune responses seems to be critical for successful regulation of MRSA infection.Recently, defects in antibacterial innate immunities have been demonstrated to occur in patients and animals following severe burn injuries (5). Innate immunity is the major host defense against early burn wound infection with MRSA (10), and classically activated macrophages (Mφ) (M1Mφ [interleukin-12-positive {IL-12⁺} IL-10⁻ Mφ]) have been identified as a major effector cell in host antimicrobial innate immunities (6, 19, 21). M1Mφ kill bacteria through the production of lysosomal enzymes, reactive oxygen intermediates, reactive nitrogen intermediates, and antimicrobial peptides (12, 21, 23). In general, resident Mφ (IL-12⁻ IL-10⁻ Mφ, isolatable from healthy donors) convert to M1Mφ following stimulation with invasive pathogens via pattern recognition receptors (19). Contrarily, a majority of thermally injured hosts are shown to be carriers of alternatively activated macrophages (M2Mφ [IL-12⁻ IL-10⁺ Mφ]) (15, 16, 32). M2Mφ have reduced abilities to kill bacteria, and soluble factors released from M2Mφ inhibit pathogen-stimulated macrophage conversion from resident Mφ to M1Mφ (15).Bacterial replication causes tissue destruction, and an abscess is commonly formed through this necrotizing process (18). An abscess, defined as a circumscribed collection of pus, is a very important host antibacterial defense against intradermal MRSA infection (8). The well-developed abscess has a wall or capsule of fibrous tissue separating it from the surrounding tissue. Histologically, the abscess lesions consist of accumulating leukocytes with live bacteria (26). In recent studies (7, 17, 26), abscess formation was caused by the accumulation of phagocytic Mφ to eliminate the pathogen. In this study, the influence of severe burn injury on abscess formation and bacterial growth at the infection site tissue was investigated for burned mice intradermally infected with MRSA. In the results, an abscess was not formed in burned mice, unlike in normal mice, after intradermal infection with MRSA. MRSA infected in burned mice at local intradermal tissues spread throughout the whole body quickly. In normal mice, IL-12-producing and IL-10-nonproducing Mφ (M1Mφ) were characterized as effector cells for abscess formation. After intradermal infection with MRSA, an abscess formed in burned mice that were inoculated with infection site tissue Mφ (M1Mφ). These results indicate that M1Mφ appearing in response to the MRSA infection are major effector cells in the host antibacterial defense. Through abscess formation, M1Mφ work to control the bacterial growth at the infection site and to inhibit the dissemination of the pathogen. M2Mφ inhibit Mφ conversion from resident Mφ to M1Mφ following bacterial stimulation. Therefore, an abscess is not formed in hosts where M2Mφ predominate, which results in the development of sepsis from local infections.     

Faecal microbial dysbiosis in children with Wiskott-Aldrich syndrome

Wiskott-Aldrich syndrome (WAS) is an X-linked primary immunodeficiency disease caused by a mutation in the WAS gene that encodes the WAS protein (WASp); up to 5-10% of these patients develop inflammatory bowel disease (IBD). The mechanisms by which WASp deficiency causes IBD are unclear. Intestinal microbial dysbiosis and imbalances in host immune responses play important roles in the pathogenesis of polygenetic IBD; however, few studies have conducted detailed examination of the microbial alterations and their relationship with IBD in WAS. Here, we collected faecal samples from 19 children (all less than 2 years old) with WAS and samples from WASp-KO mice with IBD and subjected them to 16S ribosomal RNA sequencing. We found that microbial community richness and structure in WAS children were different from those in controls; WAS children revealed reduced microbial community richness and diversity. Relative abundance of Bacteroidetes and Verrucomicrobiain in WAS children was significantly lower, while that of Proteobacteria was markedly higher. WASp-KO mice revealed a significantly decreased abundance of Firmicutes. Faecal microbial dysbiosis caused by WASp deficiency is similar to that observed for polygenetic IBD, suggesting that WASp may play crucial function in microbial homoeostasis and that microbial dysbiosis may contribute to IBD in WAS. These microbial alterations may be useful targets for monitoring and therapeutically managing intestinal inflammation in WAS.     

Comparative analysis of 16S rRNA signature sequences of the genus Idiomarina and Idiomarina woesei sp. nov., a novel marine bacterium isolated from the Andaman Sea

A Gram-negative, short rod, aerobic bacterium, designated W11^T, was isolated from seawater. Heterotrophic growth was observed at 10–45 °C and pH 6–10. Optimal growth was observed at 30–37 °C and pH 7–9. It can grow in the presence of 0.5–12% NaCl (w/v), and the optimal NaCl required for growth was 5–6%. 16S rRNA gene sequence similarity revealed that strain W11^T clustered within the radiation of the genus Idiomarina and showed 99.24% similarity with Idiomarina donghaiensis JCM 15533^T, 97.64% with Idiomarina marina JCM 15083^T, 97.37% with Idiomarina tainanensis JCM 15084^T and 97.16% with Idiomarina maritima JCM 15534^T. DNA–DNA similarities between strains W11^T with other closely related strains were below 70%. Polar lipids included a phosphatidylgylycerol, a diphosphatidylglycerol, a phosphatidylethanolamine, an unidentified phosopholipid, two unidentified aminolipids and two unidentified lipids. DNA G + C content was 41.2 ± 0.1 mol%. Major fatty acids were iso-C_15:0, iso-C_17:0, iso-C_17:1ω9c, C_16:0, iso-C_11:0 3OH and C_16:1 ω7c/C_16:1 ω7c. The isoprenoid ubiquinone was Q8. On the basis of the present polyphasic taxonomic study, strain W11^T is considered to represent a novel species of the genus Idiomarina, for which the name Idiomarina woesei sp. nov. is proposed. The type strain is W11^T (= DSM 27808^T = JCM 19499^T = LMG 27903^T).     

Microbial Fatty Acids and Thermal Adaptation

Abstract

The existing literature on the role of fatty acids in microbial temperature adaptation is reviewed. Several modes of change of cellular fatty acids at varying environmental temperatures are shown to exist in yeasts and fungi, Gram-negative bacteria, and bacteria containing iso- and anteiso-branched fatty acids, as well as in a few Gram-positive bacteria. Consequently, the degree of fatty acid unsaturation and cyclization, fatty acid chain length, branching, and cellular fatty acid content increase, decrease, or remain unaltered on lowering the temperature. Moreover, microorganisms seem to be able to change from one mode or alter the cellular fatty acid profile temperature dependently to another on lowering the temperature, as well as even within the same growth temperature range, depending on growth conditions. Therefore, the effect of the temperature on cellular fatty acids appears to be more complicated than known earlier. However, similarities found in the modes of change of cellular fatty acids at varying environmental temperatures in several microorganisms within the above mentioned groups support the existence of a limited amount of common regulatory mechanisms. The models presented enable the prediction of temperature-induced changes occurring in the fatty acids of microorganisms, and enzymatic steps of the fatty acid biosynthesis that possibly are under temperature control.     

Determination of monounsaturated double-bond position and geometry in the cellular fatty acids of the pathogenic bacterium Francisella tularensis.

The nonhydroxy fatty acid composition of Francisella tularensis is reported in detail. The double-bond configuration of the monounsaturated acids has been determined by capillary gas chromatography-mass spectrometry of the derivatized fatty acids. The monounsaturated fatty acids detected, in decreasing order of abundance, were 24:1 omega 15c, 18:1 omega 9c, 22:1 omega 13c, 20:1 omega 11c, 16:1 omega 7c, 26:1 omega 17c, and 14:1 omega 7c. The fatty acid profile found in F. tularensis, in particular the double-bond positions, represents a valuable taxonomic characteristic of this pathogenic bacterium.     

Enhanced osteocalcin expression by osteoblast-like cells (MC3T3-E1) exposed to bioactive coating glass (SiO2–CaO–P2O5–MgO–K2O–Na2O system) ions

This study tested the hypothesis that bioactive coating glass (SiO₂–CaO–P₂O₅–MgO–K₂O–Na₂O system), used for implant coatings, enhanced the induction of collagen type 1 synthesis and in turn enhanced the expression of downstream markers alkaline phosphatase, Runx2 and osteocalcin during osteoblast differentiation. The ions from experimental bioactive glass (6P53-b) and commercial Bioglass^TM (45S5) were added to osteoblast-like MC3T3-E1 subclone 4 cultures as a supplemented ion extract (glass conditioned medium (GCM)). Ion extracts contained significantly higher concentrations of Si and Ca (Si, 47.9 ± 10.4 ppm; Ca, 69.8 ± 14.0 for 45S5; Si, 33.4 ± 3.8 ppm; Ca, 57.1 ± 2.8 ppm for 6P53-b) compared with the control extract (Si < 0.1 ppm, Ca 49.0 ppm in α-MEM) (ANOVA, p < 0.05). Cell proliferation rate was enhanced (1.5× control) within the first 3 days after adding 45S5 and 6P53-b GCM. MC3T3-E1 subclone 4 cultures were then studied for their response to the addition of test media (GCM and control medium along with ascorbic acid (AA; 50 ppm)). Each GCM + AA treatment enhanced collagen type 1 synthesis as observed in both gene expression results (day 1, Col1α1, 45S5 GCM + AA: 3× control + AA; 6P53-b GCM + AA: 4× control + AA; day 5, Col1α2, 45S5 GCM + AA: 3.15× control + AA; 6P53-b GCM + AA: 2.35× control + AA) and in histological studies (Picrosirius stain) throughout the time course of early differentiation. Continued addition of each GCM and AA treatment led to enhanced expression of alkaline phosphatase (1.4× control + AA after 5 days, 2× control + AA after 10 days), Runx2 (2× control + AA after 7 days) and osteocalcin gene (day 3, 45S5 GCM + AA: 14× control + AA; day 5, 6P53-b GCM + AA: 19× control + AA) and protein expression (40×–70× control + AA after 6 days). These results indicated the enhanced effect of bioactive glass ions on key osteogenic markers important for the bone healing process.     

Physiological features of Halomonas lionensis sp. nov., a novel bacterium isolated from a Mediterranean Sea sediment

A novel halophilic bacterium, strain RHS90^T, was isolated from marine sediments from the Gulf of Lions, in the Mediterranean Sea. Its metabolic and physiological characteristics were examined under various cultural conditions, including exposure to stressful ones (oligotrophy, high pressure and high concentrations of metals). Based on phylogenetic analysis of the 16S rRNA gene, the strain was found to belong to the genus Halomonas in the class Gammaproteobacteria. Its closest relatives are Halomonas axialensis and Halomonas meridiana (98% similarity). DNA–DNA hybridizations indicated that the novel isolate is genotypically distinct from these species. The DNA G + C content of the strain is 54.4 mol%. The main fatty acids (C_18:1 ω7c, 2-OH iso-C_15:0, C_16:0 and/or C_19:0 cyclo ω8c), main polar lipids (diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and an unidentified phosphoglycolipid) and major respiratory quinone (ubiquinone Q9) were determined. The novel isolate is heterotrophic, mesophilic, euryhaline (growth optimum ranging from 2 to 8% w/v NaCl) and is able to grow under stressful conditions. The strain accumulates poly-β-hydroxyalkanoates granules and compatible solutes. Based on genotypic, chemotaxonomic and phenotypic distinctiveness, this isolate is likely to represent a novel species, for which the name Halomonas lionensis is proposed. The type strain of H. lionensis is RHS90^T (DSM 25632^T = CIP 110370^T = UBOCC 3186^T).     

Depression and altered serum lipids in cynomolgus monkeys consuming a Western diet

Research over the past 15 years has suggested a high comorbidity of depression and coronary heart disease (CHD). However the mechanisms responsible for this relationship are poorly understood. This study was designed to examine the relationships between depressive behaviors and concentrations of circulating lipids and lipid signaling molecules that may be common to both CHD and depression in a cohort of cynomolgus monkeys (Macaca fascicularis) consuming a ‘Western’ diet, enriched with saturated fat and cholesterol. Socially-housed adult female cynomolgus monkeys (n = 36) were fed the Western diet for 27 months and depressive behavior was recorded weekly. Body weight, body mass index and circulating cholesterol profiles were measured in all animals, and fatty acids (FA) and FA-based signaling molecules were measured in the 6 least and 6 most depressed monkeys. Monkeys consuming the Western diet exhibited a broad range of percent time spent in depressive behavior. The percent time spent depressed was positively correlated with total plasma and LDL cholesterol and negatively correlated with HDL cholesterol. Despite being leaner, depressed monkeys had higher concentrations of monounsaturated fats (C16:1 and C17:1), a higher ω6/ω3 polyunsaturated fatty acid (PUFA) ratio and higher concentrations of omega-6 (ω6) PUFAs, particularly C18:2ω6 and C20:3ω6. FA ratios suggest that stearoyl CoA desaturase 1 activity was increased in depressed monkeys. Depressed female cynomolgus monkeys had elevated concentrations of serum lipids and lipid signaling molecules that are typically associated with obesity, insulin resistance and cardiovascular disease, which may account in part for the comorbidity of depression and CHD.     

The effect of kaempferol and apigenin on allogenic synovial membrane-derived stem cells therapy in knee osteoarthritic male rats

BackgroundBased on the anti-inflammatory and anti-oxidant properties of kaempferol and apigenin, we hypothesized that co-injection of these phytochemicals would increase the effectiveness of cell therapy in knee osteoarthritic rats.MethodsAnterior cruciate ligament transection (ACLT) was used to induce osteoarthritis (OA). Animals were treated by weekly intra-articular injections of kaempferol (10 or 20 μM) and/or isolated MSCs from synovial membrane (SMMSCs) (3 × 106 cells), a mixture of apigenin (0.1 μM) and kaempferol alone or SMMSCs, hyaluronic acid or PBS (group size n = 6), for three weeks. After three months, the levels of IL-1β, tumor necrosis factor alpha (TNF-α), superoxide dismutase (SOD) and malondialdehyde (MDA) were measured in the cartilage homogenate. Furthermore, relative expressions of collagen II2a1, aggrecan, IL-1β, TNF-α, inducible nitric oxide synthase (iNOS), SOX-9, MMP-3 and MMP-13 were assessed using real-time PCR. Radiological evaluation, before/after treatments, and histopathological assessments were carried out to evaluate the knees.ResultsNon-toxic concentrations of kaempferol and apigenin determined to be 10, 20 μM and 0.1, 0.3 μM, respectively. In comparison with the OA group, the levels of TNF-α, IL-1β and MDA significantly decreased in OA + MSCs + kaempferol + apigenin group and a significant increase in SOD level was observed. The levels of MMP-13, MMP-3, TNF-α, IL-1β, iNOS were significantly decreased in the groups of OA + MSCs + A0.1 μM + K10 μM and OA + MSCs + K20 μM. Co-treatment of kaempferol and apigenin increased the gene expression levels of collagen IIa1, aggrecan and SOX-9 genes.ConclusionWe showed that kaempferol and apigenin potentially increase the efficiency of OA cell therapy in the rat model of ACLT-induced OA.     

Cytokine induction by Gram-positive bacteria

Despite similar clinical relevance of Gram-positive and Gram-negative infections, immune activation by Gram-positive bacteria is by far less well understood than immune activation by Gram-negative bacteria. Our group has made available highly purified lipoteichoic acids (LTA) as a key Gram-positive immunostimulatory component. We have characterized the reasons for lower potency of LTA compared to Gram-negative lipopolysaccharide (LPS), identifying lack of IL-12/IFNgamma induction as a general characteristic of TLR2 agonists, and need for presentation of LTA on surfaces for enhanced immunostimulatory potency, as major aspects. Aspects of chemokine induction, where LTA is more potent than LPS, have been addressed. Furthermore, novel complement and plant defence activation, as well as CD36 as a new LTA receptor, were identified. The bacterial costimuli and modulators of LTA inducible responses are being investigated: LTA isolated from so far 16 bacterial species, although different in structure, behave remarkably similar while whole live and killed bacteria differ with regard to the pattern of induced responses. The purification and characterization of the respective components of the bacterial cell wall has begun.     

Synthesis and transport properties of 2-ethylhexylpoly(trimethylene phosphate) – A synthetic analogue of natural teichoic acids

The paper deals with modelling the transport of magnesium and calcium ions in the cell wall of Gram-positive bacteria. The model compound, i. e. 2-ethylhexylpoly(trimethylene phosphate)

1 Structure-based IUPAC nomenclature: α-2-Ethylhexyl-ω-hydroxypoly[oxy(hydroxyphosphonol)oxytrimethylene].

(EPTP), was synthesized in order to mimic the transport mediated by lipoteichoic acids. It was found that EPTP can transport preferentially magnesium ions in an ion exchange-diffusion process with the counter-transport of hydrogen ions.     

Composition of Swine Arterial Tissue

The effects of trans-fatty acid-rich and saturated acid-rich diets on the fatty acid composition and morphology of swine arterial tissues were studied. Three groups of two-month-old swine were fed either a basal diet or a basal diet containing 8.3% margarine or butter for 4 months. The most significant change observed in the fatty acid pattern was the accumulation of 18: 2ω6 and the supperssion of both 20:4ω6 and 22:4ω6 acids in the aortic tissues of swine fed either butter or margarine as compared to swine fed the basal diet. Also, ω6 metabolites were significantly decreased in swine fed diets containing butter or margarine, as compared to those fed a basal diet. The group of swine which were fed either butter or margarine containing diets suffered a significant increase in intimal thickening of the coronary artery compared to those fed the basal diet. These thickened intima were characterized by the presence of modified smooth muscle cells, lipid containing cells, and degenerated cells without stainable lipids. However, there was no significant difference in the incidence and extent of intimal thickening of the coronary arteries between swine fed either of the two fat containing diets.     

Kupffer cell activation by different microbial lysates: Toll-like receptor-2 plays pivotal role on thromboxane A2 production in mice and humans

Thromboxane (TX) A₂ has been identified as an important intrahepatic vasoconstrictor upon Kupffer cell (KC) activation during infections such as spontaneous bacterial peritonitis (SBP). The study aimed to investigate the role of TLRs in the TXA₂ increase in liver nonparenchymal cells and their related mechanisms. Here, we identified TLR-2 as a common pathway for different microbials: microbial lysates including Gram-positive bacteria, Gram-negative bacteria, and fungi all increased TXA₂ secretion via activation of TLR-2 in human KCs, accompanied by increased expression and phosphorylation of Myd88-related pathway. Of all TLR agonists, only TLR-1, -2, and -4 agonists increased TXA₂ in human KCs. These results were further confirmed by mouse liver nonparenchymal cells. Comparing the effects of TLR-1, -2, and -4 antagonists, only TLR-2 antagonist showed inhibitory effects with all tested microbial lysates. Pretreatment with TLR-2 antagonist in human KCs blocked the secretion of IL-10, CXCL-10, TNF-α, and IL-6 induced by Gram-positive and Gram-negative bacterial stimulation. IL-23 and IL-1β were only induced by Gram-negative bacteria. Thus, TLR-2 might be a potential marker and an attractive target for future treatment of patients with SBP. In addition, IL-23 and IL-1β might distinguish early between Gram-positive and Gram-negative SBP.     

Circulating cytotoxic immune components in dominant Charcot-Marie-Tooth syndrome

Activated T cells, measured repeatedly in the demyelinating peripheral neuropathy, Charcot-Marie-Tooth syndrome (CMT: hereditary motor sensory neuropathy), might participate in myelin loss by a destructive inflammatory autoimmune process. To explore this possibility, plasma proportions of hydroxyleukotrienes, their fatty acid precursor, arachidonic acid, and lymphocyte epitopes associated with immune cell activation expression were measured in 18 adults with dominant, Type I CMT. Compared to age-matched normal controls, CMT I patients showed eicosanoid-linked immunoactivation by an elevated content of 12-hydroxy-eicosatetraenoic acid (12-HETE) in parallel with a decreased plasma percentage of its fatty acid precursor, arachidonic acid. CMT patients also had increased numbers of peripheral lymphocytes expressing activation-related epitopes, CD25⁺, CD26⁺, CD4⁺, and CD4/CD45RO⁺ primed memory cells, with enhanced CD8⁺ cytotoxic cells and soluble CD8 protein content. Therefore, endogenously stimulated CMT I lymphocytes include functional cytotoxic cells which appear to deplete the plasma fatty acid precursor of prostenoid agents during the secretion of potentially destructive cytokines.     

Postpartum changes in maternal and infant erythrocyte fatty acids are likely to be driven by restoring insulin sensitivity and DHA status

Introduction

Perinatal changes in maternal glucose and lipid fluxes and de novo lipogenesis (DNL) are driven by hormones and nutrients. Docosahexaenoic acid (DHA) reduces, whereas insulin augments, nuclear abundance of sterol-regulatory-element-binding-protein-1 (SREBP-1), which promotes DNL, stearoyl-CoA-desaturase (SCD, also Δ9-desaturase), fatty acid-(FA)-elongation (Elovl) and FA-desaturation (FADS). Decreasing maternal insulin sensitivity with advancing gestation and compensatory hyperinsulinemia cause augmented postprandial glucose levels, adipose tissue lipolysis and hepatic glucose- and VLDL-production. Hepatic VLDL is composed of dietary, body store and DNL derived FA. Decreasing insulin sensitivity increases the contribution of FA from hepatic-DNL in VLDL-triacylglycerols, and consequently saturated-FA and monounsaturated-FA (MUFA) in maternal serum lipids increase during pregnancy. Although other authors described changes in maternal serum and RBC essential-FA (EFA) after delivery, none went into detail about the changes in non-EFA and the mechanisms behind -and/or functions of- the observed changes.

Hypothesis

Postpartum FA-changes result from changing enzymatic activities that are influenced by the changing hormonal milieu after delivery and DHA-status.

Empirical data

We studied FA-profiles and FA-ratios (as indices for enzymatic activities) of maternal and infant RBC at delivery and after 3 months exclusive breastfeeding in three populations with increasing freshwater-fish intakes. DNL-, SCD- and FADS2-activities decreased after delivery. Elongation-6 (Elovl-6)- and FADS1-activities increased. The most pronounced postpartum changes for mothers were increases in 18:0, linoleic (LA), arachidonic acid (AA) and decreases in 16:0, 18:1ω9 and DHA; and for infants increases in 18:1ω9, 22:5ω3, LA and decreases in 16:0 and AA. Changes were in line with the literature.

Discussion

Postpartum increases in 18:0, and decreases in 16:0 and 18:1ω9, might derive from reduced insulin-promoted DNL-activity, with more reduced SCD- than Elovl-activity that leaves more 16:0 to be converted to 18:0 (Elovl-activity) than to MUFA (SCD-activity). Postpartum changes in ΣDNL, saturated-FA and MUFA related negatively to RBC-DHA. This concurs with suppression of both SCD- and Elovl-6 activities by DHA, through its influence on SREBP. Infant MUFA and LA increased at expense of their mothers. Sustained transport might be important for myelination (MUFA) and skin barrier development (LA). Maternal postpartum decreases in FADS2-, and apparent increases in FADS1-activity, together with increases in LA, AA, and 22:5ω3, but decrease in DHA, confirm that FADS2 is rate limiting in EFA-desaturation. Maternal LA and AA increases might be the result of rerouting from transplacental transfer to the incorporation into milk lipids and discontinued placental AA-utilization.

Implications

Perinatal changes in maternal and infant FA status may be strongly driven by changing insulin sensitivity and DHA status.     

呼吸道感染患者病原性细菌临床检验研究

目的 研究呼吸道感染患者病原性细菌临床检验措施。方法 选取2018年2月~2019年2月在我中心治疗的80例呼吸道感染患者为研究对象,采用随机数字表法分为对照组和观察组,各40例。对照组采用常规痰液收集与检验,观察组在常规检验基础上,给予相应的检验质控措施,比较两组病原性细菌检验的总检出率以及病原菌分布情况。结果 观察组病原性细菌总检出率为100.00%（革兰阴性菌70.00%、革兰阳性菌12.50%、真菌17.50%）,高于对照组的67.50%（革兰阴性菌52.50%、革兰阳性菌5.00%、真菌10.00%）,差异具有统计学意义（P＜0.05）;病原菌分布革兰阴性菌以铜绿假单胞菌与肺炎克雷伯菌最为常见,革兰阳性菌以金黄色葡萄球菌最常见。结论 呼吸道感染患者病原性细菌临床检验中,加强的检验质控措施,可提高病原性细菌检出率。革兰阴性菌、真菌是诱发呼吸道感染患者的关键病原性细菌,临床可依据药敏结果合理选择抗生素。     

Interactions of Neisseria meningitidis with human monocytes

The roles of capsule, pill and Class 5 outer-membrane proteins (Opa and Opc) of Neisseria meningitidis (Nm) in bacterial interactions with human monocytes were investigated using several meningococcal isolates of different serogroups. The presence of either Class I or Class II pili in capsulate strains of several serogroups had no significant effect on adherence to and internalisation by monocytes. Using clonal variants derived from a non-piliated serogroup A strain, C751, it was observed that capsulate bacteria (cap⁺) failed to interact with human monocytes in significant numbers whether or not they expressed outer-membrane proteins. These bacteria were also resistant to phagocytic killing. For capsule-deficient bacteria, expression of the Opc protein or OpaB_c751 correlated with high levels of association, while the expression of OpaD_c751 or OpaA_c751 resulted in comparatively lower levels. Bacteria expressing undetectable levels of Opc or Opa proteins (Opc^-, Opa) failed to interact with monocytes. In phagocytic killing assays, Opc-expressing bacteria (Opc⁺) as well as Opa-expressing bacteria (Opa⁺) were killed more readily than Opc^-, Opa bacteria (30% decrease in viability of Opc⁺ bacteria; 18%, 10% and 8% decrease in viability of OpaB⁺, OpaD⁺ and OpaA⁺ bacteria). A study of intracellular survival showed a gradual decrease in viability of both capsulate and capsule-deficient bacteria. However, proportionately greater numbers of capsule-deficient bacteria were internalized and consequently larger numbers survived over a 4-h period. Prolonged bacterial survival within phagocytic cells may have implications in dissemination of bacteria by carriage within these cells.     

Antibacterial activity of serine protease inhibitor 1 from kuruma shrimp Marsupenaeus japonicus

Serine protease inhibitors (Serpins) are a large family of protease inhibitors involved in many critical biological processes such as blood coagulation, fibrinolysis, programmed cell death, development, and innate immunity. We identified MjSerp1, a serpin in the kuruma shrimp Marsupenaeus japonicus. The MjSerp1 cDNA has a 1239 bp open reading frame (ORF) that encodes a 412–amino acid protein with a 23 aa signal peptide and a classic serpin domain. MjSerp1 has a calculated molecular mass of 46.3 kDa and a predicted isoelectric point of 5.51. MjSerp1 is mainly expressed in the hepatopancreas and the intestines, and is moderately expressed in hemocytes. Expression pattern analysis indicated that MjSerp1 is upregulated in the hepatopancreas after Vibrio anguillarum challenge. rMjSerp1 inhibits three Gram-positive bacteria and two Gram-negative bacteria, but does not inhibit phenoloxidase activity. The microorganism binding assay showed that rMjSerp1 closely binds to both Gram-positive and Gram-negative bacteria. MjSerp1 also exhibits inhibitory activity against microbial serine proteases, such as subtilisin A and proteinase K, indicating that MjSerp1 acts as a microbial serine protease inhibitor. rMjSerp1 injection into shrimp enhances V. anguillarum clearance, but MjSerp1 knockdown through RNA interference impairs Vibrio clearance in vivo. These results indicate that MjSerp1 functions as a direct effector in the bacterial clearance of M. japonicus. All together, our findings provide novel evidences for the serine protease inhibitor in shrimp immunity.     

Molecular evidence of Trichobilharzia franki Müller and Kimmig, 1994 (Digenea: Schistosomatidae) in Radix auricularia from Central Italy

The molecular approach was used to identify the first focus of human cercarial dermatitis occurring during the spring–summer season in Vico Lake, a Natural Reserve Area in Central Italy. Sequences of 586 bp length of the partial region of 18S and ITS-1 ribosomal DNA from cercariae were obtained. They were compared with extant GenBank sequences of Trichobilharzia. Accordingly, the ocellate furcocercariae were identified as belonging to the species Trichobilharzia franki Müller and Kimmig, 1994. Sequences of the 18S (712 bp) and ITS-2 (218 bp) rDNA gene of snails belonging to the family Lymnaeidae collected in the study area have allowed detection of this bird schistosome in Italy in Radix auricularia. The prevalence of the schistosome infection in snails was P = 9.6%. The reduction in habitat disturbance at the lake, as a result of its recent dedication as a nature reserve, has enhanced bird species abundance and richness. This has favoured the establishment of the life cycle of T. franki in the study area.