A-Factor as a selective agent for isolation of the soil Gram-negative bacterium strain--the producent of an antibacterial antibiotic]

It was shown the stimulating role of A-factor on soil prokaryotes growth. Soil sample culturing on agar medium, containing A-factor, resulted in the colony forming units (CFU) increasing in comparison with culturing on the medium without this regulator. Gram-negative bacteria were the reason of CFU increasing; previously the effect of A-factor on bacteria of this group was not shown. Gram-negative rod bacterial strain No. 35 was isolated and shown that CFU number was approximately twice increased at A-factor concentration in agar medium 2 and 7 mcg/ml; high A-factor concentration up to 28 mcg/ml was not effective. Isolated strain No. 35 is the producer of antibiotic, effective against gram-positive bacteria.     

Reconstruction of the properties of smooth-muscle cell sarcolemma on planar lipid membranes

A method is described for reconstruction of certain sarcolemma characteristics of smooth muscle cells in the small intestine of a rabbit on the planar lipid membranes (PLM). The method is based on the use of fusogenic properties of certain lipid preparations. The ultrasound dispergates of azolectin and egg lecithin in combined incubation with sarcolemma vesicles of smooth-muscle cells promote a 1.4-1.8-fold increase of the total ATPase activity of the sarcolemma. Cholesterol, dipalmithoil lecithin, total brain phospholipids, inhibit the ATPase activity. Sarcolemma vesicles preincubated with azolectin lyposomes in the ratio which induces maximum ATPase activation (sarcolemma protein: azolectin-1:6) interact intensively with PLM from azolectin. PLM modified in such a way is channel-conductive, sensitive to tetraethylammonium and sign of the applied voltage.     

Inducible surface proteins from some strains of Pseudomonas species bacteria while adapting to cobalt

The possibility of increasing resistance of some Pseudomonas strains to cobalt at adaptation to monotonous increasing its concentration was studied. Strains Pseudomonas fluorescens B5242 and Pseudomonas fluorescens B894 are capable to increase its resistance in such conditions via inducible synthesis of protective surface proteins. The molecular masses of such proteins were 55.0; 45.0 and 33.0 kDa for P. fluorescens B5242 strain.     

<Emphasis Type="Italic">Burkholderia</Emphasis> Hep_Hag autotransporter (BuHA) proteins elicit a strong antibody response during experimental glanders but not human melioidosis

Background  

The bacterial biothreat agents Burkholderia mallei and Burkholderia pseudomallei are the cause of glanders and melioidosis, respectively. Genomic and epidemiological studies have shown that B. mallei is a recently emerged, host restricted clone of B. pseudomallei.     

Structural and functional aspects of bacterial membranes and liposomes interactions

Effect of exogenous lipids on the morphology and enzymatic activity of Bacillus cereus B4368 membrane has been studied. Specific character of different lipids action on the membrane enzyme activity was found. This peculiarity had been taken into account by using liposomes in biological systems.     

Bone formation rather than inflammation reflects Ankylosing Spondylitis activity on PET-CT: a pilot study

Introduction

Positron Emission Tomography - Computer Tomography (PET-CT) is an interesting imaging technique to visualize Ankylosing Spondylitis (AS) activity using specific PET tracers. Previous studies have shown that the PET tracers [¹⁸F]FDG and [¹¹C](R)PK11195 can target inflammation (synovitis) in rheumatoid arthritis (RA) and may therefore be useful in AS. Another interesting tracer for AS is [¹⁸F]Fluoride, which targets bone formation. In a pilot setting, the potential of PET-CT in imaging AS activity was tested using different tracers, with Magnetic Resonance Imaging (MRI) and conventional radiographs as reference.

Methods

In a stepwise approach different PET tracers were investigated. First, whole body [¹⁸F]FDG and [¹¹C](R)PK11195 PET-CT scans were obtained of ten AS patients fulfilling the modified New York criteria. According to the BASDAI five of these patients had low and five had high disease activity. Secondly, an extra PET-CT scan using [¹⁸F]Fluoride was made of two additional AS patients with high disease activity. MRI scans of the total spine and sacroiliac joints were performed, and conventional radiographs of the total spine and sacroiliac joints were available for all patients. Scans and radiographs were visually scored by two observers blinded for clinical data.

Results

No increased [¹⁸F]FDG and [¹¹C](R)PK11195 uptake was noticed on PET-CT scans of the first 10 patients. In contrast, MRI demonstrated a total of five bone edema lesions in three out of 10 patients. In the two additional AS patients scanned with [¹⁸F]Fluoride PET-CT, [¹⁸F]Fluoride depicted 17 regions with increased uptake in both vertebral column and sacroiliac joints. In contrast, [¹⁸F]FDG depicted only three lesions, with an uptake of five times lower compared to [¹⁸F]Fluoride, and again no [¹¹C](R)PK11195 positive lesions were found. In these two patients, MRI detected nine lesions and six out of nine matched with the anatomical position of [¹⁸F]Fluoride uptake. Conventional radiographs showed structural bony changes in 11 out of 17 [¹⁸F]Fluoride PET positive lesions.

Conclusions

Our PET-CT data suggest that AS activity is reflected by bone activity (formation) rather than inflammation. The results also show the potential value of PET-CT for imaging AS activity using the bone tracer [¹⁸F]Fluoride. In contrast to active RA, inflammation tracers [¹⁸F]FDG and [¹¹C](R)PK11195 appeared to be less useful for AS imaging.     

Interaction of energized bacteria cells with particles of colloidal gold: peculiarities and kinetic model of the process.

It is found that the cells of Bacillus cereus B-4368 at energized state can concentrate the colloidal gold particles on their surface. It is shown that the process depends on metabolic reactions proceeding on the plasma membrane. The inhibitory analysis permits to suppose that the metal concentration is due to the functioning of ATP-dependent generator of the transmembrane potential, apparently, of proton ATPase. Kinetic characteristics of the process show the presence of an intermediate state in the formation of biomineral aggregates. A kinetic model of the studied process is suggested which describes the experimental data well.     

Interaction of the glycoprotein from the Bacillus pumilis cell wall with liposomes

The methods of centrifugation and gel-filtration on Sephadexes G-50 and G-150 were used to study the interaction of Bacillus pumilis cell wall glycoprotein component having the molecular weight of 50 kDa (GP-50) with lyposomes from bacterial lipids. GP-50 is shown to sorb on such liposomes and disturb their barrier properties inducing yield of low-molecular label. GP-50 exerts no effect on properties of liposomes from egg lecithin. Electrostatic forces are supposed to play a decisive role in initial acts of GP-50 interactions with lipid phase of microbial envelopes.     

Obtaining bioluminescent bacterial strains for detection of thallium ions

The possibility of Alcaligenes eutrophus T1 luxphenotype creation by temperature induced mutagenesis has been shown. These mutants are able to emit light after induction by thallium ions. This biological method of thallium detection possesses high specificity and sensitivity (0.5 microM of metal). Such microbial cells can be used to quantify bioavailability of thallium part in the environment.