Immunitat und Infektion最新文献

The detection of microorganisms responsible for septicemia from blood and their susceptibility testing against antimicrobial agents is the main requirement to treat this life threatening infection. The sample of specimens, their transport and the handling of blood cultures in the microbiological laboratory are really important, e.g. the number of blood cultures needed, the proper interval between these cultures, the volume of blood cultures and the use of sterile techniques. Recommendations are given for this important management. Conventional methods for blood cultures as well as new automatically working techniques are described.

The phagocytosis rate of polymorphonuclear leucocytes was measured by flow-cytometry. Vital bacteria were incubated in whole blood. 111 blood samples were measured, 54 in diabetic patients (14 type 1 and 40 type 2), the rest of 57 samples in healthy controls. Results showed firstly, that a decompensation in glucose metabolism in diabetic patients correlated with a decrease in phagocytosis. The HbA1 level was more closely correlated than the glucose level. The second result was, that despite a similar grade of decompensation in type 1 and type 2 diabetic patients, the phagocytosis was significantly lower in type 1 diabetes. No correlation was found concerning age and sex. These findings show, that the impact on granulocytic function in diabetes is of multifactorial origin, not only a shorter or longer elevation of the serum glucose level can explain it solely.

Major trauma and consecutively associated infectious complications have a major impact on the mechanisms of the specific immune response and the nonspecific inflammatory reaction. The trauma-induced host defense abnormalities become strikingly evident with the analysis of cytokine synthesis patterns. The dissociation of cell-mediated immune responses following trauma is based upon an overrepresentation of suppressor-active monocytes and inadequate T-cell help in parallel. Corresponding dysregulation of cytokine production appears within many facets. Complement, endotoxin and antigen antibody complexes cause a massive activation of monocytes with an abnormal release of essential mediators, like PGE2, IL-1, IL-6, IL-8, TGF-beta and TNF-alpha. The regulation of cytokine synthesis under stressful conditions is differentially regulated for the individual mediators, either on a transcriptional or a posttranscriptional level. In our opinion, the endogenous provisions of the organism for survival following major injury are inadequate and from this hypothesis we derive the necessity for a substantial exogenous therapeutic intervention. The primary target of modern immunotherapy must be to inhibit the conversion of a systemic inflammatory reaction in immunocompromised patients towards a status of bacterial sepsis. Different approaches appear to be feasible to avoid the development of late multiorgan failure. These interventions have to be utilized preventively in a controlled manner as early as possible after trauma has occurred, and they must effectively protect different cell systems (lymphocytes, monocytes, PMNs and endothelial cells).

Pseudomonas aeruginosa is an opportunistic pathogen causing a variety of diseases, especially in immunocompromised patients like those suffering from cystic fibrosis (CF) where these bacteria preferentially colonize the bronchopulmonary tract. A high intrinsic antibiotic resistance and its ability to synthesize and secrete numerous different virulence factors are regarded as biological properties contributing to the pathogenicity of P. aeruginosa. Among the virulence factors are many enzymes which have been characterized in detail with respect to their molecular properties. Environmental factors regulating the synthesis and release of extracellular enzymes have been identified as e.g. the concentration of Fe- and PO4-ions, choline, pH, and osmolarity. In addition, low molecular weight substances named autoinducers were identified as regulators which are synthesized by the bacteria. Therefore, P. aeruginosa represents an example for the remarkably complex relationship between pathogenic bacteria and their human host.

We report about four children, who suffered from myositis caused by beta-hemolytic group A streptococci (GAS). The cases were observed during the last 12 months, and differed much in severity. Soft tissue infections caused by GAS are reported with increasing frequency from the USA, Australia and Europe. They occur in hitherto healthy children and young adults, mostly without a predisposing trauma. In children, a preceding varicella infection is often found. Some patients develop a streptococcal toxic shock syndrome with a letality of 20-50%. The bacteria, which can be isolated from normally sterile body sites, are morphologically inconspicuous, and are mostly of the serological type M1 or M3.

Cold labile serum and plasma proteins can cause a variety of clinicopathological symptoms. Due to altered physicochemical properties, cryoglobulins and cryofibrinogens may cause increased serum viscosity, cold dependent protein precipitation or, in rare cases, serum gelification. Cold agglutinins, on the other hand, cause temperature dependent agglutination of erythrocytes and eventually hemolysis. All pathological cold dependent serum and plasma phenomena are associated with either neoplasma, autoimmune disorders, various infections or are considered as "essential". While the diagnosis of these conditions remained largely unchanged during the last 10 years, new aspects regarding etiology, pathogenesis, and therapy have arisen.

Seven ELISAs, two westernblots and one immunofluorescence assay for serological detection of parvovirus-B19-infection were compared with regard to their sensitivity and specificity. All ten assays are commercially available and use recombinant proteins (VP1, VP2) from bacterial and eukaryotic expression systems and synthetic viral peptides as antigens. The ELISA assays comprise indirect ELISA and mu-capture systems. All assays were tested for their sensitivity with follow-up sera from 21 patients with acute parvovirus B19 infections. The specificity was analysed by 194 sera from pregnant women and from patients with acute other virus infections or rheumatoid factors, but without acute parvovirus infection. Only three ELISAs, both westernblots and the immunofluorescence assay can be recommended for the IgG-measuring (prevalence). For the detection of an acute parvovirus infection, especially during pregnancy, two ELISAs show good IgG- and IgM-results, one ELISA is less recommendable and all other assays show only a poor IgM-specificity.