Detection of antibodies to the teichoic acids of the Staphylococcus aureus cell wall in the sera of osteomyelitis patients

The comparative analysis of serum samples from patients with hematogenic and post-traumatic osteomyelitis for the presence of antibodies to the teichoic acids of the cell wall of S. aureus has been carried out by means of ELISA. The investigation has shown that the test system developed on the basis of teichoic acids can be used for confirming the diagnosis of osteomyelitis. An attempt to use this system for the dynamic observation of the disease has been made.     

Role of carbon substrates of culture media on Mycobacterium smegmatis susceptibility to antitubercular agents

Influence of medium composition on Mycobacterium smegmatis growth and susceptibility to antituberculosis drugs (ATD)--isoniazid and rifabutin--was studied. It was shown that addition of phospholipids (PL) in form of liposomes to meat peptone broth resulted in activation of M. smegmatis growth and decrease of its susceptibility to ATD. Growth characteristics of M. smegmatis and its susceptibility to ATD were studied using variants of modified on source of carbon synthetic medium Sauton as growth substrate. It was revealed that presence of acetate or PL in growth medium results in significant decrease of M. smegmatis susceptibility to isoniazid and rifabutin. It was suggested that this phenomenon is determined by activation of glyoxylate cycle by PL and fatty acids, which, in its turn, can stimulate expression of a number of proteins, including cell membrane pumps excreting antibiotics out of microbial cell.     

Silver nanoparticles from <Emphasis Type="Italic">Dendropanax morbifera</Emphasis> Léveille inhibit cell migration,induce apoptosis,and increase generation of reactive oxygen species in A549 lung cancer cells

Green synthesized silver nanoparticles have significant potential in the pharmaceutical field because of their biological functions such as antioxidant and anticancer activities. Novel silver nanoparticles synthesized from Dendropanax morbifera Léveille leaves (D-AgNPs) exhibit antimicrobial activity and reduce the viability of cancer cells without affecting the viability of RAW 264.7 macrophage-like cells. In this study, we evaluated the anticancer effect of D-AgNPs by measuring the levels of reactive oxygen species (ROS) production and toxicity against A549 and HepG2 cell lines. The effect of D-AgNPs on cell migration, induction of apoptosis, and modification of gene and/or protein expression of cancer-related markers was determined using A549 cells. D-AgNPs exhibited cytotoxicity in A549 and HepG2 cell at different concentrations and enhanced the production of ROS in both cell lines. An increase in cell apoptosis and a reduction in cell migration in A549 cells were also observed after D-AgNP treatment. Furthermore, the effect of D-AgNPs in A549 cells was shown to be related to modification of the EGFR/p38 MAPK pathway. Our data provide the first evidence supporting the potential of D-AgNPs as a possible anticancer agent, particularly for the treatment of non-small cell lung carcinoma.     

Antibodies to Staphylococcus aureus teichoic acids in the pathogenesis of chronic osteomyelitis

The titers of antibodies to S. aureus cell-wall teichoic acids have been determined in 97 orthopedic and traumatic patients with purulent diseases, differing by the activity of the process, by means of the enzyme immunoassay. These antibodies appeared in the patients' blood in active osteomyelitic process of staphylococcal etiology.     

Culturability and Coexistence of Colony-Forming and Single-Cell Marine Bacterioplankton

Culturability and coexistence of bacterioplankton exhibiting different life strategies were investigated in the Baltic Sea and Skagerrak Sea. Bacterial numbers were estimated using a dilution-to-extinction culturing assay (DCA) and calculated as the most probable number, based on six different methods to detect bacterial growth in the DCA. Irrespective of the method used to detect growth, the fraction of multiplying cells never exceeded 10%, using the total count of 4′,6′-diamidino-2-phenylindole (DAPI)-stainable cells as a reference. Furthermore, the data also showed that non-colony-forming bacteria made up the majority of the viable cells, confirming molecular results showing dominance of non-colony-forming bacteria in clone libraries. The results obtained are in agreement with previous observations, indicating that bacterial assemblages in seawater are dominated by small, active subpopulations coexisting with a large group of inactive cells. The ratio of colony-forming to non-colony-forming bacteria was approximately 10 to 20 times higher in the brackish Baltic Sea than in the Skagerrak Sea. These two sea areas differ in (for example) their levels of bacterial production, dissolved organic carbon, and salinity. We suggest that the relative importance of colony-forming versus non-colony-forming bacterioplankton may be linked to environmental characteristics.     

Oligotrophic bacterioplankton with a novel single-cell life strategy

A large fraction of the marine bacterioplankton community is unable to form colonies on agar surfaces, which so far no experimental evidence can explain. Here we describe a previously undescribed growth behavior of three non-colony-forming oligotrophic bacterioplankton, including a SAR11 cluster representative, the world's most abundant organism. We found that these bacteria exhibit a behavior that promotes growth and dispersal instead of colony formation. Although these bacteria do not form colonies on agar, it was possible to monitor growth on the surface of seawater agar slides containing a fluorescent stain, 4',6'-diamidino-2-phenylindole (DAPI). Agar slides were prepared by pouring a solution containing 0.7% agar and 0.5 micro g of DAPI per ml in seawater onto glass slides. Prompt dispersal of newly divided cells explained the inability to form colonies since immobilized cells (cells immersed in agar) formed microcolonies. The behavior observed suggests a life strategy intended to optimize access of individual cells to substrates. Thus, the inability to form colonies or biofilms appears to be part of a K-selected population strategy in which oligotrophic bacteria explore dissolved organic matter in seawater as single cells.     

Oligotrophic Bacterioplankton with a Novel Single-Cell Life Strategy

A large fraction of the marine bacterioplankton community is unable to form colonies on agar surfaces, which so far no experimental evidence can explain. Here we describe a previously undescribed growth behavior of three non-colony-forming oligotrophic bacterioplankton, including a SAR11 cluster representative, the world's most abundant organism. We found that these bacteria exhibit a behavior that promotes growth and dispersal instead of colony formation. Although these bacteria do not form colonies on agar, it was possible to monitor growth on the surface of seawater agar slides containing a fluorescent stain, 4′,6′-diamidino-2-phenylindole (DAPI). Agar slides were prepared by pouring a solution containing 0.7% agar and 0.5 μg of DAPI per ml in seawater onto glass slides. Prompt dispersal of newly divided cells explained the inability to form colonies since immobilized cells (cells immersed in agar) formed microcolonies. The behavior observed suggests a life strategy intended to optimize access of individual cells to substrates. Thus, the inability to form colonies or biofilms appears to be part of a K-selected population strategy in which oligotrophic bacteria explore dissolved organic matter in seawater as single cells.     

Global patterns of diversity and community structure in marine bacterioplankton

Because of their small size, great abundance and easy dispersal, it is often assumed that marine planktonic microorganisms have a ubiquitous distribution that prevents any structured assembly into local communities. To challenge this view, marine bacterioplankton communities from coastal waters at nine locations distributed world-wide were examined through the use of comprehensive clone libraries of 16S ribosomal RNA genes, used as operational taxonomic units (OTU). Our survey and analyses show that there were marked differences in the composition and richness of OTUs between locations. Remarkably, the global marine bacterioplankton community showed a high degree of endemism, and conversely included few cosmopolitan OTUs. Our data were consistent with a latitudinal gradient of OTU richness. We observed a positive relationship between the relative OTU abundances and their range of occupation, i.e. cosmopolitans had the largest population sizes. Although OTU richness differed among locations, the distributions of the major taxonomic groups represented in the communities were analogous, and all local communities were similarly structured and dominated by a few OTUs showing variable taxonomic affiliations. The observed patterns of OTU richness indicate that similar evolutionary and ecological processes structured the communities. We conclude that marine bacterioplankton share many of the biogeographical and macroecological features of macroscopic organisms. The general processes behind those patterns are likely to be comparable across taxa and major global biomes.