Clone of Staphylococcus aureus phage type 187 isolated from people

The aim of this study was to examine whether Staphylococcus aureus of phage type 187 are genetically homogenous with the use of digestion of chromosomal DNA with SmaI and separation of the DNA by pulsed-field gel electrophoresis (PFGE). Sixteen S. aureus phage type 187 were isolated from the hospital patients (12) and the healthy carriers (4) in twelve medical centres in Poland during 1991 and 2005. The PFGE typing proved that the phage type 187 isolates have the same PFGE type (except for one) and constitute one clone.     

Tuftsin--new analogues and properties

Tuftsin, a natural tetrapeptide of sequence TKPR, occuring in the blood of humans and other mammals, capable of stimulating certain white blood cells (monocytes, macrophages, and neutrophils), was isolated at Tufts University in 1970 by Najjar and Nishioka. Tuftsin is a compound with a wide spectrum of biological activities, notable enhances phagocytosis, immune response, bactericidal, tumoricidal and antifungal activities. This article concerns new analogues and properties of tuftsin.     

Hoc protein regulates the biological effects of T4 phage in mammals

We previously investigated the biological, non-antibacterial effects of bacteriophage T4 in mammals (binding to cancer cells in vitro and attenuating tumour growth and metastases in vivo); we selected the phage mutant HAP1 that was significantly more effective than T4. In this study we describe a non-sense mutation in the hoc gene that differentiates bacteriophage HAP1 and its parental strain T4. We found no substantial effects of the mutation on the mutant morphology, and its effects on electrophoretic mobility and hydrodynamic size were moderate. Only the high ionic strength of the environment resulted in a size difference of about 10 nm between T4 and HAP1. We compared the antimetastatic activity of the T2 phage, which does not express protein Hoc, with those of T4 and HAP1 (B16 melanoma lung colonies). We found that HAP1 and T2 decreased metastases with equal effect, more strongly than did T4. We also investigated concentrations of T4 and HAP1 in the murine blood, tumour (B16), spleen, liver, or muscle. We found that HAP1 was rapidly cleared from the organism, most probably by the liver. Although HAP1 was previously defined to bind cancer cells more effectively (than T4), its rapid elimination precluded its higher concentration in tumours. Maria Zembala and Janusz Boratynski contributed equally to this work.     

Relationships among recent Alpine Cladocera remains and their environment: implications for climate-change studies

Our objective was to assess the potential of Cladocera from mountain lakes for climate reconstruction. We related Cladocera from surface sediments of Alpine lakes (1,502–2,309 m asl) to 29 abiotic environmental variables using statistical methods. The environmental dataset included water chemistry, lake depth, and bi-hourly water-temperature logs, which were used to assess mean monthly water temperatures, dates of freezing and breakup, spring and autumn mixing. We found 14 different Cladocera of the families Bosminidae, Daphniidae, and Chydoridae. Lakes without Cladocera (eight lakes) were cold and/or ultra-oligotrophic, whereas lakes with planktonic and littoral Cladocera (19 lakes) were warmer and/or less oligotrophic. Lakes with only littoral Cladocera (18 lakes) had intermediate water temperatures/trophy. Changes in Cladocera assemblages were related to changes in climate, nutrients, and/or alkalinity. We found a climate threshold at which Bosminidae disappeared in 95% of the lakes. For climate-change research, we propose studying Cladocera along transects that include climatic thresholds. Guest editor: Piet Spaak Cladocera: Proceedings of the 7th International Symposium on Cladocera     

Lethal factor of Clostridium histolyticum kills cells by apoptosis

In this study, for the first time, Clostridium histolyticum lethal factor was purified by ammonium sulfate precipitation of culture broth, centrifugation through an Amicon filter device and hydrophobic interaction chromatography. The purified lethal factor was devoid of proteolytic activity. At a concentration of 150 ng mL(-1) the lethal factor killed 50% of HeLa cells within 24 h of exposure. Abrogation of actin filaments, activation of caspases, fragmentation of nuclear DNA as well as ultrastructural changes indicated that the cell death occurred by apoptosis. The apoptotic action of the lethal factor is in agreement with changes induced in animal tissues by administration of C. histolyticum culture medium.