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Synergistic hemolysins of coagulase-negative staphylococci (CoNS)

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Różalska M., Derczyńska A., Maszewska A.
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2015
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vol. 62
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issue 4
757-764
EN
A total of 104 coagulase negative staphylococci, belonging to S. capitis, S. hominis, S. haemolyticus and S. warneri, originating from the collection of the Department of Pharmaceutical Microbiology (ZMF), Medical University of Lodz, Poland, were tested for their synergistic hemolytic activity. 83% of strains produced δ-hemolysin, however, the percentage of positive strains of S. haemolyticus, S. warneri, S. capitis and S. hominis was different - 98%, 78%, 75% and 68%, respectively. Highly pure hemolysins were obtained from culture supernatants by protein precipitation with ammonium sulphate (0-70% of saturation) and extraction by using a mixture of organic solvents. The purity and molecular mass of hemolysins was determined by TRIS/Tricine PAGE. All CoNS hemolysins were small peptides with a molar mass of about 3.5 kDa; they possessed cytotoxic activity against the line of human foreskin fibroblasts ATCC Hs27 and lysed red cells from different mammalian species, however, the highest activity was observed when guinea pig, dog and human red blood cells were used. The cytotoxic effect on fibroblasts occurred within 30 minutes. The S. cohnii ssp. urealyticus strain was used as a control. The antimicrobial activity was examined using hemolysins of S. capitis, S. hominis, S. cohnii ssp. cohnii and S. cohnii ssp. urealyticus. Hemolysins of the two S. cohnii subspecies did not demonstrate antimicrobial activity. Cytolysins of S. capitis and S. hominis had a very narrow spectrum of action; out of 37 examined strains, the growth of only Micrococcus luteus, Corynebacterium diphtheriae and Pasteurella multocida was inhibited.
2
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Differentiation of polyvalent bacteriophages specific to uropathogenic Proteus mirabilis strains based on the host range pattern and RFLP

76%
Maszewska A., Wójcik E., Ciurzyńska A., Wojtasik A., Piątkowska I., Dastych J., Różalski A.
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2016
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vol. 63
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issue 2
303-310
EN
Urinary tract infections (UTIs) caused by P. mirabilis are difficult to cure because of the increasing antimicrobial resistance of these bacteria. Phage therapy is proposed as an alternative infection treatment. The aim of this study was to isolate and differentiate uropathogenic P. mirabilis strain specific polyvalent bacteriophages producing polysaccharide depolymerases (PDs). 51 specific phages were obtained. The plaques of 29 bacteriophages were surrounded by halos, which indicated that they produced PDs. The host range analysis showed that, except phages 58B and 58C, the phage host range profiles differed from each other. Phages 35 and 45 infected all P. mirabilis strains tested. Another 10 phages lysed more than 90% of isolates. Among these phages, 65A, 70, 66 and 66A caused a complete lysis of the bacterial lawn formed by 62% to 78% of strains. Additionally, phages 39A and 70 probably produced PDs. The phages' DNA restriction fragment length polymorphism (RFLP) analysis demonstrated that genomes of 51 isolated phages represented 34 different restriction profiles. DNA of phage 58A seemed to be resistant to selected EcoRV endonuclease. The 33 RFLP-EcoRV profiles showed a Dice similarity index of 38.8%. 22 RFLP patterns were obtained from single phage isolates. The remaining 12 restriction profiles consisted of 2 to 4 viruses. The results obtained from phage characterization based on the pattern of phage host range in combination with the RFLP method enabled effective differentiation of the studied phages and selection of PD producing polyvalent phages for further study.
3
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The balance between pro- and anti-inflammatory cytokines in the immune responses to BCG and DTwP vaccines

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Druszczynska M., Kowalewicz-Kulbat M., Maszewska A., Rudnicka K., Szpakowski P., Wawrocki S., Wlodarczyk M., Rudnicka W.
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2015
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vol. 62
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issue 4
913-921
EN
Bacillus Calmette-Guérin (BCG) and pertussis vaccines have been found to be insufficient and their further improvement is required. In order to develop improved vaccines, a better understanding of the main pathways involved in the host's protective immunity to the pathogens is crucial. We address the question as to whether the balance between pro- and anti-inflammatory cytokine production might affect the host responses to BCG and diphtheria-tetanus toxoids-whole cell pertussis (DTwP) vaccines. The study population consisted of 118 healthy people, age range 18-30 years, who had been subjected to BCG and DTwP vaccination according to the state policy. Tuberculin skin testing (TST) revealed a delayed type hypersensitivity (DTH) to PPD (purified protein derivative) in 53% volunteers. The variability in development of the BCG-driven DTH to tuberculin prompted us to address a question as to whether Th1/Th2 polarization is involved in the lack of skin responsiveness to PPD. PPD-stimulated blood lymphocytes from TST+ participants produced significantly more IFN-γ and less IL-10 than lymphocytes from TST- volunteers. However, TST- volunteers' sera contained more anti-pertussis IgG but not anti-diphtheria toxin IgG. Mycobacterial antigens and particularly PPD induced a higher expression of HLA-DR and co-stimulatory CD80 receptors on DCs from TST+ than TST- participants. BCG but not PPD pulsed DCs from TST- volunteers produced significantly more IL-10. Mycobacterial antigen stimulated DCs from TST+ volunteers induced a more intense IFN-γ production in co-cultures with autologous lymphocytes than the cells from TST- participants. Differences among the types of dendritic cell activities contribute to development of tuberculin reactivity in BCG vaccinated volunteers.
4
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Proteus sp. – an opportunistic bacterial pathogen – classification, swarming growth, clinical significance and virulence factors

52%
Różalski A., Torzewska A., Moryl M., Kwil I., Maszewska A., Ostrowska K., Drzewiecka D., Zabłotni A., Palusiak A., Siwińska M., Stączek P.
Acta Universitatis Lodziensis. Folia Biologica et Oecologica
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2012
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vol. 8
1-17
EN
The genus Proteus belongs to the Enterobacteriaceae family, where it is placed in the tribe Proteeae, together with the genera Morganella and Providencia. Currently, the genus Proteus consists of five species: P. mirabilis, P. vulgaris, P. penneri, P. hauseri and P. myxofaciens, as well as three unnamed Proteus genomospecies. The most defining characteristic of Proteus bacteria is a swarming phenomenon, a multicellular differentiation process of short rods to elongated swarmer cells. It allows population of bacteria to migrate on solid surface. Proteus bacteria inhabit the environment and are also present in the intestines of humans and animals. These microorganisms under favorable conditions cause a number of infections including urinary tract infections (UTIs), wound infections, meningitis in neonates or infants and rheumatoid arthritis. Therefore, Proteus is known as a bacterial opportunistic pathogen. It causes complicated UTIs with a higher frequency, compared to other uropathogens. Proteus infections are accompanied by a formation of urinary stones, containing struvite and carbonate apatite. The virulence of Proteus rods has been related to several factors including fimbriae, flagella, enzymes (urease - hydrolyzing urea to CO2 and NH3, proteases degrading antibodies, tissue matrix proteins and proteins of the complement system), iron acqusition systems and toxins: hemolysins, Proteus toxin agglutinin (Pta), as well as an endotoxin - lipopolysaccharide (LPS). Proteus rods form biofilm, particularly on the surface of urinary catheters, which can lead to serious consequences for patients. In this review we present factors involved in the regulation of swarming phenomenon, discuss the role of particular pathogenic features of Proteus spp., and characterize biofilm formation by these bacteria.
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