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Phagocytic capacity and the amount of PMN-granulocytes which take part in phagocytosis was investigated in patients with septicemia and polytrauma patients in comparison to PMN-granulocytes withdrawn from healthy volunteers by use of a standardized test-system in which autoclavated S.cerevisiae is the phagocytic agent. Influence of polyvalent immunoglobulin preparations together with patients' own serum incubation was compared with serum preincubation only in the test system mentioned above. It became evident that phagocytic capacity and the number of PMN-granulocytes which take part in phagocytosis in patients with septicemia are primary on a significant higher rate than those of other groups. PMN-granulocytes from polytraumated patients showed a significant higher rate on ingestion of S.cerevisiae pretreated with patients' own serum - especially after preopsonisation with immunoglobulins - than granulocytes from patients with septicemia or healthy volunteers.

A modified agar-diffusion method is used to test the bactericidal efficacy of antibacterial substances (model substance: Gentamicin) that have been mixed with Palacos osseous cement. Holes of a diameter slightly larger than the diameter of the cylindric Palacos test block are cut from the agar plate. The remaining space (inner wall of the hole--edge of the test body) is filled with various eluate media. The release of active antibacterial substances from polymethylmetacrylates can thereby be determined under nearly physiologic conditions at varying pHs by direct antibacterial testing.

Copper acetate of suitable specific surface (Kupferacetat Fargua) and copper acetate plus acridin orange intermixed with Palacos powder have bactericidal efficacy against gram-negative and gram-positive bacterias depending on bacterial species. The Palacos osseous cement releases the intermixed substances over long periods of time. There exists a mutual influence on the bactericidal increase of both substances.

Hexacyanoferrate-compounds are suitable to indicate the efficacy of antimicrobial substances to sulfate-reducing bacteria. They act as a cytochemical indicator system. (Stübner, 9), e. g. K3FeIII(CN)6 showes FeS formation before any visible blackening of the medium. By using hexacyanoferrate compounds it is easier to determine the efficacy of antimicrobial agents. In addition a microscopical control is recommended to detect damaged or avital bacteria in the limiting concentrations of the agents.

Hexacyanoferrat-compounds are suitable 1. to indicate the valence of Fe-ions in cultures of desulfuricants (Desulfovibrio spec., Desulfotomaculum) in fluid and solid medium before and after inoculation; 2. stain directly the sulfate-reducing bacteria in presence of Fe-ions and give a colour-reaction of those parts of the cell containing Fe-compounds, e.g. FeS. Therefore they act as a cytochemical indicator system. The chemical base of the reactions are as follows: (1) 4HS + SO42 leads to H2S + 2H2O + OH- H2S leads to H+ + HS- leads to 2H+ + S2- (in the bacteria) (2) FeIII-salt + S2-leads to Fe2S3 leads to 2FeIIS + S 2FeIIS + FeIII(CN6) leads to FeIIIFeII(CN)6 (blue complex-compound).

A comparative study on the phagocytic capacity of human and rat polymorphonuclear leucocytes was performed. The activity of rat leucocytes was assessed by using the rat polyvinyl sponge model and the granuloma pouch model. Isolated human leucocytes were either suspended in buffer or homologous serum. Assessments of the susceptibility of Pseudomonas aeruginosa or Klebsiella pneumoniae to the antimicrobial action of leucocytes revealed that the activity of normal human leucocytes and rat leucocytes was very similar, whereas human leucocytes obtained from chronically infected patients were significantly more active. Pretreatment of the bacteria with subinhibitory mezlocillin and azlocillin concentrations with or without immunoglobulin G rendered the bacteria more susceptible to the antimicrobial action of both types of leucocytes. Again results obtained by the different methods were very similar.

Neuraminidase in concentrations up to 0.5 nu/0.1 ml (0.05 nu/0.1 ml) added to Limulus amebocyte lysate (LAL) in equal volumes (each 0.1 ml) releases a gelation reaction. Human AB-serum - subjected to immunelectrophoresis - is used as an indicator system to show that neuraminidase is bond to the LAL (incorporated in the gel). If there is a free amount of neuraminidase immunelectrophoresis of the serum glycoproteins indicates the typical changes previously described by Müller (6, 7). LAL does not cause any immunelectrophoretically detectable changes on serum glycoproteins by itself in the temperature range from +4 degrees C to 37 degrees C. It must be assumed that neuraminidase in a certain amount is releasing the coagulation system.

Ten strains of Pseudomonas aeruginosa isolated from different clinical sources were incubated with immunoglobulin preparations for i.v. use. This resulted in the release of beta-lactamases normally cellbound in the periplasmic space. The amount of released beta-lactamases--depending on the degree of cell wall alteration--was spectrophotometrically determined by the use of nitrocefin as an indicator substance. Beta-lactamase release varies according to strain specificity and depends on the chemical modification of the immunoglobulins used.

Vital fluorochromation of mycoplasmas can be obtained with acridine derivatives. Stained with acridine-orange und 9-aminoacridine chloride-1-hydrate mycoplasmas appear as yellow (green) fluorescing homogeneous spots or discs under the fluorescence microscope, the exact appearance depending on the concentration of the fluorochrome and the absorption by nucleic acids. Non-specific supplements and undermixed bacteria have significantly different fluorescence. Depending on the metachromasia of acridine-orange and on double-fluorescing with acridine-orange and 9-aminoacridine chloride-1-hydrate, the bacterial cell wall is green, the protoplasma red. The method is suitable as a screening test for mycoplasma.

Heat inactivated S. cerevisiae as phagocytic particle and subsequent staining with trypan blue-eosin solution is suitable to give evidence of phagocytic capacity and the number of human polymorphonuclear leucocytes which are engaged in phagocytosis. After preincubation of the yeasts with i.v. IgG-preparations--and on a higher rate--with volunteers' own serum increase of phagocytic capacity and of the number of granulocytes which take part in phagocytosis occurs. The test is suitable to compare this granulocyte function of patients under different clinical conditions depending on the underlying disease and seems to be of use to decide where clinical application of polyvalent immunoglobulin therapy is indicated.

The effect of azlocillin, ticarcillin and cefsulodin, respectively, on the susceptibility of Pseudomonas aeruginosa to the antimicrobial action of human polymorphonuclear leukocytes (PMN) was investigated under two different experimental conditions. Firstly, phagocytic capacity as well as bactericidal activity of PMN were assessed in a homologous system, i.e. the clinical isolate as well as the PMN and serum were obtained from the same patient. Secondly, ultrastructural studies were performed by electron microscopy. Preincubation of bacteria with subinhibitory beta-lactam concentrations augmented the phagocytic capacity as well as the antibacterial activity of PMN; azlocillin tended to be the most effective drug in this respect. The enhanced susceptibility to leukocyte killing is not due to an increased antibacterial action of the beta-lactams in the presence of PMN. These findings suggest that a non-immunological linkage between bacteria and PMN may exist which may be based on the interaction between bacterial- and eukaryotic surface structures, respectively. It may be assumed that the antipseudomonal beta-lactam antibiotics may cause changes in the surface structures of P. aeruginosa, thus rendering them more susceptible to phagocytosis. Preliminary data indicate that the lectins on the outer membrane of P. aeruginosa are not mannose sensitive. Electron microscopic studies revealed that azlocillin pretreatment of bacteria brought about a high undulation and a disruption of the outer membrane. These morphological changes may render bacteria more vulnerable to the antimicrobial action of PMN. It may be speculated that an interference with surface adhesins and induction of morphological changes may affect engulfment and intracellular killing of bacteria.

After determination of granulocyte basic parameters of polymorphonuclear neutrophilic leukocytes obtained from 5 unselected intensive care unit patients and 5 healthy volunteers phagocytosis of an E. coli strain isolated from clinically proven infection (urinary tract infection) was investigated with and without preincubation of the strain with subinhibitory concentrations (1/4 and 1/2 minimum inhibitory concentration; incubation time: 30 min) of cefaclor, erythromycin and doxycycline. The results show that it is very difficult to compare granulocyte functions because they differ widely in individual ranges among both groups. Nevertheless in comparison to the untreated strain a higher amount of ingestion by the granulocytes of both collectives could be obtained after preincubation with cefaclor or erythromycin; thereby cefaclor seemed to be the most effective drug.

Ten strains of Pseudomonas aeruginosa isolated from different clinical sources were incubated with immunoglobulin preparations for i.v. use. This resulted in the release of beta-lactamases normally cell-bound in the periplasmic space. The amount of released beta-lactamases - depending on the degree of cell wall alteration - was spectrophotometrically determined by the use of nitrocefin as an indicator substance. beta-lactamase release varies according to strain specificity and depends on the chemical modification of the immunoglobulins used.

In patients with different neurological diseases with blood-brain barrier dysfunction subjected to diagnostic CSF-tap, simultaneous determinations of ofloxacin concentrations in serum and in CSF were carried out. The results show that ofloxacin penetrates well into the CSF achieving adequate bactericidal concentrations against most of the common causative pathogens of meningitis.