Background: When postneurosurgery patients develop fever, there are no convenient methods to immediately indicate the site of infection. The choice of empirical antibiotic therapy is evidently different in nosocomial meningitis compared with ventilator-associated pneumonia or urinary tract infection. Conventional bacterial cultures run a risk of being false negative due to antibiotic prophylaxis, and direct microscopic analysis of cerebrospinal fluid (CSF) from such patients has limited diagnostic value. Because of the substantial mortality associated with nosocomial meningitis, broad spectrum antibiotics in high dosage are, therefore, commonly administered. Neutrophils as a part of the innate immunity system, trap and kill bacteria by neutrophil extracellular traps (NETs). Neutrophil extracellular traps are composed of extracellular DNA which is released to the CSF during bacterial meningitis. Using a combination of sulphated-glucosaminoglycan and aniline dyes, a measurement method was developed that reacts to extracellular host DNA and changes color within 1 minute in proportion to the amount of NETs in the body fluid tested. The present study aimed to evaluate the sensitivity and specificity of the "rapid NETs test" in identifying the site of infection. Methods: We performed analysis on the left-over CSF samples (n = 199) that were collected routinely at neurosurgical intensive care unit. No samples were included after patients were transferred to the ward. Besides CSF, bronchoalveolar fluid, and urine samples were collected in febrile patients. The "rapid NETs test" was used for simultaneous analysis of the fresh left-over samples. The final diagnosis was settled at discharge. Results: A total of 75 (64%) patients had received empirical antibiotic therapy against nosocomial meningitis, whereas only 19 patients of these cases (16%) had a verified diagnosis. The rapid NETs test could distinguish a verified meningitis (n = 19) with 89.5% sensitivity and 92.5% specificity. The test also identified ventilator-associated pneumonia (n = 32) with 93.8% sensitivity and 86.8% specificity. However, the test was not reliable in identifying nosocomial urinary tract infection (sensitivity and specificity, 78.6% and 55.2%, respectively). Conclusions: The rapid NETs test indicated the site of infection in febrile patients postneurosurgery with clinically relevant sensitivity and specificity, which might show its potential to minimize the unnecessary use of antibiotics.

There is a strong association between periodontal disease and atherosclerotic cardiovascular disorders. A key event in the development of atherosclerosis is accumulation of modified lipoproteins within the arterial wall. We hypothesise that patients with periodontitis have an altered lipoprotein profile towards an atherogenic form. Therefore, the present study aims at identifying modifications of plasma lipoproteins in periodontitis. Lipoproteins from ten female patients with periodontitis and gender- and age-matched healthy controls were isolated by density-gradient ultracentrifugation. Proteins were separated by 2D gel-electrophoresis and identified by map-matching or by nano-LC followed by MS. Apolipoprotein (Apo) A-I (ApoA-I) methionine oxidation, Oxyblot, total antioxidant capacity and a multiplex of 71 inflammation-related plasma proteins were assessed. Reduced levels of apoJ, phospholipid transfer protein, apoF, complement C3, paraoxonase 3 and increased levels of α-1-antichymotrypsin, apoA-II, apoC-III were found in high-density lipoprotein (HDL) from the patients. In low-density lipoprotein (LDL)/very LDL (VLDL), the levels of apoL-1 and platelet-activating factor acetylhydrolase (PAF-AH) as well as apo-B fragments were increased. Methionine oxidation of apoA-I was increased in HDL and showed a relationship with periodontal parameters. α-1 antitrypsin and α-2-HS glycoprotein were oxidised in LDL/VLDL and antioxidant capacity was increased in the patient group. A total of 17 inflammation-related proteins were important for group separation with the highest discriminating proteins identified as IL-21, Fractalkine, IL-17F, IL-7, IL-1RA and IL-2. Patients with periodontitis have an altered plasma lipoprotein profile, defined by altered protein levels as well as post-translational and other structural modifications towards an atherogenic form, which supports a role of modified plasma lipoproteins as central in the link between periodontal and cardiovascular disease (CVD).

Background and objective: Several studies have shown an association between periodontitis and cardiovascular disease (CVD). Atherosclerosis is the major cause of CVD and a key event in the development of atherosclerosis is accumulation of lipoproteins within the arterial wall. Bacteria are the primary etiologic agents in periodontitis and Porphyromonas gingivalis (P. gingivalis) is the major pathogen in the disease. Several studies support the role of modified LDL in atherogenesis, however, the pathogenic stimuli that induce the changes and the mechanisms by which this occur are unknown. This study aims at identifying alterations in plasma lipoproteins induced by the periodontopathic bacteria P. gingivalis in vitro. Material and Methods: Plasma lipoproteins were isolated from whole blood treated with wild type and gingipain-mutants (lacking either the Rgp- or Kgp gingipains) of P. gingivalis by density/gradient-ultracentrifugation and studied using two-dimensional gel electrophoresis followed by matrix-assisted laser desorption ionization mass spectrometry. P. gingivalis-induced lipid peroxidation and antioxidant levels were measured by thiobarbituric acid reactive substances (TBARs) and antioxidant assay kits, respectively, and lumiaggregometry was used for reactive oxygen species (ROS) and aggregation. Results: P. gingivalis exerted substantial proteolytic effects on the lipoproteins. The Rgp gingipains were responsible for producing two apoE, as well as two apoB-100, fragments in LDL, and the Kgp gingipain produced an un-identified fragment in HDL. P. gingivalis and its different gingipain variants induced ROS, and consumed antioxidants. Both the Rgp and Kgp gingipains were involved in inducing lipid peroxidation. Conclusions: P. gingivalis has the potential to change the expression of lipoproteins in blood which may represent a crucial link between periodontitis and cardiovascular disease.

OBJECTIVE: Cough and fever are the initial symptoms of lower respiratory infection. Severe cases might be fatal. Therefore, particularly in the non-equipped centers, the lack of diagnostic methods to identify the severe cases has resulted in overconsumption of antibiotics. On the basis of the knowledge about non-specific immune response at the site of injury, we developed a colorimetric dip-test that shows abrupt, sensitive and quite specific color change upon contact with sputum in the cases of lower respiratory infection. We further explored the mechanism of the test. RESULTS: We detected deoxyribonucleic acid (DNA) and hepatocyte growth factor in the sputum of patients that suffered from respiratory infection (n = 18). The results differed significantly (P < 0.0001) from age-matched patients (n = 18) with other respiratory disorders and highly correlated with the index-test results (Spearman Rank test = 0.84). DNA with a concentration more than 0.03 mg/ml induced a visible and stable color change on index-test within 1 min. The test recognized all of the cases with respiratory infection and the specificity was 72%. With a high negative predictive value. The index test detects, inter alia, cell-free DNA in sputum and might safely rule-out respiratory infection in 2/3 of cases that present symptoms of acute respiratory infection.

Antimicrobial resistance needs to be tackled from new angles, and antimicrobial peptides could be future candidates for combating bacterial infections. This study aims to investigate in vitro the bactericidal effects of the lantibiotic gallidermin on Staphylococcus epidermidis and Staphylococcus aureus, possible cytotoxic effects and its impact on host‐microbe interactions. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of gallidermin were determined, and cytotoxicity and proinflammatory effects of gallidermin on fibroblasts, red blood cells (RBCs) and in whole blood were investigated. Both MIC and MBC for all four tested strains of S. epidermidis was 6.25 μg/ml. Both MIC and MBC for methicillin‐sensitive S. aureus was 12.5 μg/ml and for methicillin‐resistant S. aureus (MRSA) 1.56 μg/ml. Gallidermin displayed no cytotoxic effects on fibroblasts, only a high dose of gallidermin induced low levels of CXCL8 and interleukin‐6. Gallidermin hemolyzed less than 1% of human RBCs, and did not induce reactive oxygen species production or cell aggregation in whole blood. In cell culture, gallidermin inhibited the cytotoxic effects of the bacteria and totally suppressed the bacteria‐induced release of CXCL8 and interleukin‐6 from fibroblasts. We demonstrate that gallidermin, expressing low cell cytotoxicity, is a promising candidate for treating bacterial infections caused by S. epidermidis and S. aureus, especially MRSA.