The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Urea and uraease (U-ase) activity were determined in water samples taken from the surface layers of 17 lakes of different trophic status. Urea concentrations were inversely correlated with the trophic status of the studied lakes and varied from below the detection limit to 25 μmol 1⁻¹. Maximal potential ureolytic activity (Vmax) ranged from 0.2 to 7.0 μmol 1⁻¹ h⁻¹. The highest urea concentrations...
The sensitivity of bacteria to the bactericidal activity of serum depends on the structure and organization of the bacterial outer membrane. Sialic acid has been found in the O-specific region of bacterial lipopolysaccharide (LPS) and it plays an essential role in protecting Gram-negative bacteria against the bactericidal activity of human and animal serum. The susceptibility of Gram-negative bacilli...
Lipophilic corynebacteria isolated as natural flora of human skin were examined. Among 119 assayed strains 94% presented a hydrophobic cell surface and 75.6 % were able to form biofilms. These attributes, as well as aggregation in liquid media, were statistically connected with each other and promote the developing of biofilms on solid surfaces. This was characteristic of all the lipophilic Corynebacterium...
Coagulase-negative staphylococci (CoNS) are often responsible for cases of chronic ostitis and osteomyelitis, especially in patients with orthopedic prosthesis/implants. The aim of this study was to characterize CoNS isolated from ambulatory patients with chronic ostitis/osteomyelitis and to compare them by PFGE (pulsed-field gel electrophoresis). Out of 263 bacterial strains isolated from wounds/sinuses...
The results of two experiments with wheat grain inoculated with Penicillium verrucosum are reported. In Experiment I, wheat grain, containing 10, 20 and 30% water, was incubated for 2 weeks at 10, 15, 21 and 28°C. In Experiment II, wheat grain, containing 14, 16, 18, 20 and 22% water, was incubated for 2 weeks at 10, 15, and 20°C. At initial moisture content (IMC) of the wheat grain up to 16% neither...
Yeast-like fungi are the most common cause of fungal infections in humans. Actually, in the age of opportunistic infections and increasing resistance, development of modern antifungal agents becomes a very important challenge. This paper describes synthesis and antimicrobial assay of four naturally occurring peptide antibiotics (aurein 1.2, citropin 1.1, temporin A, uperin 3.6) and three chemically...
Studies of α-amylase production by Bacillus subtilis (CM3) isolated earlier from cow dung microflora, were carried out. The optimum temperature, pH and incubation period for amylase production were 50-70°C, 5.0-9.0 and 36 h, respectively. Enzyme secretion was very similar in the presence of any of the carbon sources tested (soluble starch, potato starch, cassava starch, wheat flour, glucose, fructose,...
The replication system of plasmid pMTH4 (22 kb) of dichloromethane-degrading Paracoccus methylutens DM12 (Alphaproteobacteria) has been cloned within a mini-replicon pMTH100 (4.7 kb) and preliminarily characterized. Functional analysis, performed with a series of mutated plasmid mini-derivatives, showed that the replicator region consists of three elements: (i) gene repA coding for a replication initiation...
Tannins are water-soluble polyphenolic compounds found in plants as secondary metabolites. The presence of these substances in the barks of eight different plants was initially examined and their crude extracts were used separately as a substrate for production of tannase through submerged fermentation by Bacillus licheniformis KBR6. Tannase production as well as biodégradation of the substrate reached...
Bioinformatic analysis of the genome sequence of Neisseria gonorrhoeae revealed presence of four specific prophage islands. Based on the similarity with other DNA phage sequences they seem to belong to the filamentous ssDNA phages group. Phages belonging to this group are also present in the genome of Neisseria meningitidis. The nucleotide and amino acids sequence of NgoΦ6 and NgoΦ7 show similar genetic...
Ferric iron reductases activities have been occurred in 91% of investigated enterococci strains. Maximum activity occurred with coenzyme NADH as the reductant and the presence of cofactor FMN was necessary. Mg(II) ions has not stimulated reductases activity. Treatment of cells with proteolytic enzymes had not effect on iron reduction. The whole cells and cell fraction - cytoplasmic membrane and cytoplasm...
It has been suggested that some microorganisms may play a role in the etiology or progression of atherosclerotic plaques. The purpose of this study was to assess for the presence of Helicobacter pylori and cytomegalovirus (CMV) DNA using polymerase chain reaction (PCR) technique in vascular-wall specimens obtained during autopsy. Four to 5 mm long samples from 3 different vascular wall specimens (coronary,...
The susceptibility of 96 strains of Listeria monocytogenes isolated from food to antibiotics and disinfectants currently used in human therapy, veterinary, medicine and food industry was determined by a standard operating procedure - broth dilution method. Antimicrobial agents included the β-lactams ampicillin and penicillin, the lantibiotic nisin, and the disinfectants benzalkonium chloride and chlorhexidine...
It was found that the soil-dwelling fungus Rhizoctonia praticola 93A was capable to produce laccase in submerged cultures. Effects of culture conditions on the enzyme biosynthesis in shaken flask and aerated bioreactor cultures were evaluated to improve the yields of the process. Production of extracellular laccase was considerably intensified by the addition of Cu²⁺ to a carbon-limited and nitrogen-sufficient...
The aim of this study was to evaluate methicillin resistance detection methods currently used when studying coagulase-negative staphylococci (CoNS). The resistance to oxacillin of 142 strains from seven species of CoNS isolated from the Intensive Care Unit environments was tested. The methods used were: disc diffusion test with cefoxitin (FOX₃₀) and oxacillin (OX₁), oxacillin agar screen test with...
Until recently, the diagnosis of systemic mycoses was mainly based on traditional methods producing late and inconclusive results. Currently used methods of serological diagnostics are generally based on detection of cell wall components of selected pathogenic fungal species - mannoproteins, functioning as a antigenic markets. There are big hopes for adaptation of commercially available assays to...
Bacterial endospores are complex structures residing inside endospore-forming, mainly gram-positive bacteria. The process of sporulation is considered a simple example of cell differentiation. Endospores enable the organism to resist environmental stresses. Sporulation can be divided into several stages, from axial DNA filamentation to mother cell lysis. The structure and formation of an endospore...
Twenty-five yeast cultures, mainly of human origin, belonging to four pathogenic yeast species - Candida albicans, Candida krvsei, Candida parapsilosis, and Candida tropicalis were tested for their sensitivity to ten basidiomycetous and eleven ascomycetous yeast species isolated from the water and soil environments and from tree leaves. The best killer activity among basidiomycetous species was exhibited...
The presence of class 1 integrons was investigated in 156 epidemiologically unrelated Salmonella Typhimurium isolates. Of these 156 isolates, 70 were of definitive phage type DT104 and 86 were strains of various phage type, RDNC and untypable, designated here as non-DT104 strains. Intégrons were found in 47 of DT104 isolates (67.1%), while in all strains with characteristic pentaresistance (R-type...
In the present paper we focused on the potential role of human lactoferrin for the intracellular replication rate of T. gondii BK tachyzoites following our earlier observation that Toxoplasma gondii was able to bind human lactoferrin but not serum transferrin. The study was performed in vitro on human CaCo-2 epithelial cells and mouse L929 fibroblasts. We found that the multiplication of the parasite...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.