Properties and potential application of efficient biosurfactant produced by Pseudomonas sp. KZ1 strain

Increasing use of biosurfactants has stimulated the search for new and efficient biosurfactant-producing bacterial strains, preferably nonpathogenic ones. The aim of the present study was to characterize a new isolated Pseudomonas sp. KZ1 strain and its exocellular surface active compounds. After examining several mineral media of different compositions, the bioreactor-scale production of biosurfactants under optimum conditions was tested. Then, the composition of the isolated biosurfactants was investigated by Fourier-transform infrared spectroscopy and gas chromatography-mass spectrometry analysis and their surface active properties were characterized by adsorption parameters. The results indicated that the Pseudomonas sp. KZ1 biosurfactant had the critical micelle concentration of 0.12 g L^-1 and decreased the surface tension decreased to 31.7 mN m^-1. Moreover, the biosurfactant increased the rate of biodegradation of diesel oil by the strains: Pseudomonas sp. KZ1, Pseudomonas sp. OS4 and Achromobacter sp. KW1. The obtained biosurfactant showing attractive properties is a promising and much 'greener' alternative in the application for surfactant-enhanced biodegradation of hydrocarbons.

Human herpesvirus type 8 seroprevalence among patients in immunosuppression state

Human herpesvirus 8 (HHV 8) is implicated in the etiology of neoplastic disorders, especially in HIV-infected and immunosuppressed people, but knowledge about seroprevalence of HHV 8 in general or selected populations is still insufficient. In this study the presence of IgG antibodies to HHV 8 in groups of immunosuppressed patients was tested.

Detection of EBV infection in different etiologic groups of patients

The ability of two diagnostic tests (ELISA and IF) to detect of EBV infection in etiologically different group of patients was compared: cases of chronic lymphoadenopatis, confirmed mononucleosis or suspected EBV infection, tumors like leukemia or lymphoma. The presence of specific IgM and IgG antibodies for different EBV antigens was studied. The results obtained indicated that as many as 17 out of 32 tested serum samples presented different interpretation of EBV infection in both tests used. High number of discordant results was observed in detection of EA-IgG. The highest number of discordant results was observed in group of patients with tumors, while the lowest in group of cases diagnosed or suspected for EBV infection.

[Temperature sensitive mutant of Herpes simplex virus type 1. II. Neurovirulence and latency]

The course of acute infection of mice with ts mutant or the native strain DNA and the antigens of HSV in brain nerve cells were determined. Virus DNA was detected in brains of all mice in both animal groups while the virus antigens--only in cells of mice infected with the native strain. It can be suggested, therefore, that the ability of ts mutant to replicate in central nervous system of the infected mice is lacking or much lower. The detection of virus nucleic acid 3-5 months after virus infection might indicate a possibility of establishing latent infection. However, ts mutant showed a significantly lower possibility of latency induction, as compared with highly virulent strains. It was found that the mutant ability to induce latent infection was markedly increased when mice were treated with both ts mutant and Depo-Medrol as immunosuppressive agent. This finding shows both a possibility of increase of frequency of latent infections in the state of immunosuppression, and of activation of the latent infection (recurrence of acute form of infection).

[Temperature sensitive mutant of Herpes simplex virus type 1. I. Pathogenicity and immunogenicity]

The aim of the study was to characterize biological features of the sensitive mutant of HSV-1, derived from McIntyre strain by numerous virus passages at lowered replication temperature (28 degrees C). Pathogenicity of obtained ts mutant for inbred mice lines, CFW/Pzh and BALB/cPzh, was determined. Statistically significant decrease in virulence of the mutant for these mouse lines was demonstrated, as compared with the native virus strain, propagated at 37 degrees C. Immunogenic activity of ts mutant of HSV-1 defined by the possibility of mouse protection against infection with high virulent was determined. Mice, which at the time of immunization with ts mutant received Depo-Medrol--an immunosuppressive agent--were also found to be capable of inducing defense mechanisms to infection with the native strain.

Neutron density distributions deduced from antiprotonic atoms

The differences between neutron and proton density distributions at large nuclear radii in stable nuclei were determined. Two experimental methods were applied: nuclear spectroscopy analysis of the antiproton annihilation residues one mass unit lighter than the target mass and the measurements of strong-interaction effects on antiprotonic x rays. Assuming the validity of two-parameter Fermi neutron and proton distributions at these large radii, the conclusions are that the two experiments are consistent with each other and that for neutron rich nuclei it is mostly the neutron diffuseness which increases and not the half-density radius. The obtained neutron and proton rms radii differences are in agreement with previous results.

Immunogenic activity of HSV-1 temperature sensitive mutant's proteins in mono- and polyvalent systems of immunization

Immunogenic activity of herpes simplex type 1 temperature sensitive mutant's (ts HSV-1 mutant) proteins was tested in two systems: monovalent and polyvalent with other attenuated virus strains (measles and mumps). The guinea pigs were used as animal model. In monovalent system the humoral response in animals infected with ts HSV-1 mutant (1 or 2 doses) was studied and compared to results received for HSV-1 native strain. In polyvalent system the immunological response induced by ts HSV-1 mutant in the presence of RNA virus strains was tested.

[Evaluation of the usefulness of various PCR method variations and nucleic acid hybridization for CMV infection in immunosuppressed patients]

In diagnosis of CMV infection various laboratory methods are used. The methods based on detection of viral nucleic acids have been introduced routinely in many laboratories. The aim of this study was to compare nucleic acid hybridisation method and various variants of PCR methods with respect to their ability to detect CMV DNA. The studied material comprised 60 blood samples from 19 patients including 13 renal transplant recipients and 6 with acute leukaemia. The samples were subjected to hybridisation (Murex Hybrid Capture System CMV DNA) and PCR carried out in 3 variants: with one pair of primers (single PCR), nested PCR and Digene SHARP System with detection of PCR product using a genetic probe in ELISA system. The sensitivity of the variants ranged from 10(0) particles of viral DNA in nested PCR to 10(2) in single PCR. The producer claimed the sensitivity of the hybridisation test to be 3 x 10(5) and it seems to be sufficient for detection of CMV infection. The obtained results show that sensitivity of hybridisation was comparable to that of single PCR and the possibility of obtaining quantitative results makes it superior, on efficacy of antiviral therapy, especially in monitoring CMV infection in immunossuppressed patients and in following the efficacy of antiviral treatment.

Usefulness of hybridization and PCR methods in monitoring of CMV infection in renal transplant recipients

The purpose of this work was to compare hybridization and PCR methods as diagnostic tests in diagnosing and monitoring CMV infection. The investigation was performed in a group of 24 renal transplant recipients treated with ATG. The results we obtained suggest that quantitative variant of hybridization is more useful in diagnosing the infection than PCR, because it enables to monitor the infection. DNA CMV level of about 60 pg/ml or the increasing level in the subsequent samples should be a sign to start antiviral therapy.