Porcine interferon-gamma inhibits the growth of Legionella pneumophila in WiREF cells in vitro.

The intracellular growth of Legionella pneumophila in WiREF (Wistar rat embryonal fibroblast) cells was inhibited by porcine interferon-gamma. The effect was compared with that of different human interferons (alpha and gamma). The growth inhibition was dose-dependent and required the pretreatment of WiREF cells with interferon. The development of an antibacterial state of the cells was observed. When interferon was added together with bacteria or 1 d after the infection there was no inhibition. Also, there was no direct antibacterial effect of the interferon. In addition, cell pretreatment with a combination of interferon and antibiotics failed to show a synergistic effect.

Evaluation of EIA kits for the detection of HIV antibodies.

We compared four commercially available enzyme immunoassay (EIA) kits for the detection of HIV antibodies using immunoblot analysis as a confirmatory test. The kits gave satisfactory results as far as sensitivity and specificity are concerned as required for the use in the laboratories of blood banks. For the sera of patients on haemodialysis, haemophiliacs, patients "under observation" for AIDS and homosexuals the results obtained by Behring and Organon kits were less satisfactory, as the number of false positive results was much higher than with kits produced by Genetic and Wellcome. The frequency of false negative results was small in the tests using Organon and Genetic kits, while using Behring and Wellcome kits no false negative results were found.

Septicaemia and meningitis with campylobacter fetus subspecies intestinalis.

Two cases of infection with Campylobacter fetus subspecies intestinalis are reported. In a 46-year-old farmer the development of septicaemic campylobacteriosis with acute gastroenterocolitis was favoured by malnutrition due to chronic alcoholism. After treatment with erythromycin the patient recovered completely. The second patient, a 40-year-old worker with meningitis, recovered after combined streptomycin-erytro-mycin therapy. In both patients antibodies against homologous and reference strains of Campylobycter fetus subspecies intestinalis, serotype 1 (Mitscherlich) were demonstrated in titres ranging from 1:16 to 1:64 by type the complement-fixation test.

Some biological characteristics of Escherichia coli strains isolated from acute diarrhoeal diseases of infants.

The aim of this study was to evaluate the methods of biological characterization of Escherichia coli strains, in order to use them as screening tests in clinical microbiological laboratories. In two thirds of the 45 E. coli, isolated from acute intestinal infection of infants, different factors of virulence were found. The strains showed prevalently an enterotoxigenic character (66,6%), which was in correlation with the increased permeability (62,2%). Adhesive properties were present in 20% of E. coli independent of their enterotoxigenicity; only 11,1% of the strains had penetrating abilities. The rabbit skin model seems to be accurate and quick for ETEC screening purposes, as is the guinea-pig eye for the EIEC. The mouse intestinal loop has been found sensitive but time-consuming. The infant mouse model is simple and quick, but in this study it has not given optimal results. The Vero cell culture system is simple and easy to perform, but at least for some strains the preparations should be concentrated. The investigation of adhesiveness by haemagglutination is possible to conduct in every small clinical laboratory. Our opinion is, however, that after the isolation of E. coli from different pathological materials, the determination of the antigenic structure of the strains is necessary and later on the additional biological characterization should be performed.