Biomedical subjects

K Wolska

Publications and source records attributed to K Wolska.

At least 19 recordsLinked to original sources

PubMed2006

The hemagglutinating activity of Pseudomonas aeruginosa strains isolated from humans and animals.

The presence and type of adhesins occurring in Pseudomonas aeruginosa strains were determined by hemagglutination test with a 3% suspension of normal and trypsin-treated human group A erythrocytes, with or without the addition of sugar inhibitors (D-mannose, D-glucose, L-fucose, D-galactose, D-fructose, lactose, N-acetylneuraminic acid, N-acetylglucosamine and N-acetylgalactosamine). This study showed that a low percentage of Pseudomonas aeruginosa strains caused the agglutination of normal erythrocytes. Trypsin treatment of erythrocytes did not affect the hemagglutinating properties, indicating that hemagglutination was not dependent upon a trypsin-sensitive protein on the erythrocytes surface. Most of the studied strains agglutinated RBCs at 37 degrees C. A great variability in the inhibiting activity on studied strains was observed among the carbohydrates tested. These results demonstrated the predominant role of N-acetylglucosamine, N-acetylgalactosamine and N-acetylneuraminic acid for Pseudomonas aeruginosa adhesion to RBCs.

Animals↗

PubMed2001

Adherence of Pseudomonas aeruginosa strains to solid surfaces.

The aim of this study was to evaluate adherence of 59 strains of Pseudomonas aeruginosa to nitric-acid cleansed glass surfaces. There were differences in adherence between the investigated strains. The highest adherence was noticed among human strains (the average percentage was 13.3 +/- 7.51%) and the lowest adherence was determined among swine strains (the average percentage amounted 6 +/- .37%). We conclude that strains of Pseudomonas aeruginosa isolated from humans colonise glass surfaces better than strains isolated from animals.

Animals↗

PubMed1999

[Bactericidal activity of human, swine and cattle serum against pseudomonas aeruginosa strains].

The aim of this study was to assess of bactericidal activity of human, swine and cattle serum against 136 of Pseudomonas aeruginosa strains isolated from people, fishes, domestic and fur animals. The mechanism of the bactericidal activity of serum against gram-negative bacteria is complex and involves the participation of complement, antibodies and lysozyme (1, 5, 7, 8, 10, 11, 13, 14, 24, 25, 27, 30). The susceptibility of gram-negative rods to serum is differentiated. Pseudomonas aeruginosa strains are the most resistant (17, 25, 30). This opportunistic pathogen produce proteases that destroy complement components and immunoglobulins (3, 18, 19). The bactericidal activity of serum was determined after 3 hours incubation of bacteria in 50% serum by the method of Jankowski (1981) (5). The results of this study indicate that 71% of this strains were resistant to swine serum action, 68% of this strains were resistant to bovine serum and 57% of the Pseudomonas aeruginosa strains were sensitive to human serum. The P. aeruginosa strains isolated from fishes were the most sensitive to serum action and the strains isolated from people and cattle were most resistant to the bactericidal activity of serum.

Animals↗

PubMed1996

Components of multiprotein-RNA complex that controls transcription elongation in Escherichia coli phage lambda.

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Adenosine Triphosphate↗

PubMed1995

Bipartite function of a small RNA hairpin in transcription antitermination in bacteriophage lambda.

Transcription of downstream genes in the early operons of phage lambda requires a promoter-proximal element known as nut. This site acts in cis in the form of RNA to assemble a transcription antitermination complex which is composed of lambda N protein and at least four host factors. The nut-site RNA contains a small stem-loop structure called boxB. Here, we show that boxB RNA binds to N protein with high affinity and specificity. While N binding is confined to the 5' subdomain of the stem-loop, specific N recognition relies on both an intact stem-loop structure and two critical nucleotides in the pentamer loop. Substitutions of these nucleotides affect both N binding and antitermination. Remarkably, substitutions of other loop nucleotides also diminish antitermination in vivo, yet they have no detectable effect on N binding in vitro. These 3' loop mutants fail to support antitermination in a minimal system with RNA polymerase (RNAP), N, and the host factor NusA. Furthermore, the ability of NusA to stimulate the formation of the RNAP-boxB-N complex is diminished with these mutants. Hence, we suggest that boxB RNA performs two critical functions in antitermination. First, boxB binds to N and secures it near RNAP to enhance their interaction, presumably by increasing the local concentration of N. Second, boxB cooperates with NusA, most likely to bring N and RNAP in close contact and transform RNAP to the termination-resistant state.

Bacterial Proteins↗

PubMed1985

Evidence that ribosomal protein S10 itself is a cellular component necessary for transcription antitermination by phage lambda N protein.

Bacteriophage lambda N gene product acts to modify host RNA polymerase allowing the formation of a termination-resistant transcription apparatus. Previous studies have demonstrated that the nusE71 mutation that has altered the ribosomal protein S10 prevents N action in vivo. Using a coupled transcription-translation system, we demonstrate here that purified S10 protein as well as the 30S ribosomal subunit is sufficient to restore N activity in the nusE mutant extract, allowing antitermination of Rho-dependent and Rho-independent terminators. This provides direct biochemical evidence that the S10 protein itself is one of the cellular components necessary for the formation of an antitermination apparatus.

Bacterial Proteins↗

PubMed1984

Transcription antitermination in vitro by lambda N gene product: requirement for a phage nut site and the products of host nusA, nusB, and nusE genes.

Employing specifically engineered plasmids in which the expression of E. coli galK cistron is regulated by transcription termination, we have analyzed the antitermination function of phage lambda N gene product in S30 extracts. Antitermination by N, dependent on its site of action, nutL, is defective in the extracts prepared from nusA, nusB, and nusE mutants. By complementation analysis, we demonstrate that none of the these nus mutations affects the synthesis of N or the other nus gene products to cause a defect in antitermination. Rather, these mutations have inactivated a set of specific host components, the Nus factors, which are essential for N activity. Curiously, an appreciable portion of N and Nus complementation activities of an S30 extract is ribosome-associated. The significance of this finding remains to be uncovered.

Bacteriophage lambda↗

PubMed1972