All posts by Postępy Mikrobiologii

Wirus cytomegalii – problem zakażeń wrodzonych

Cytomegalovirus – problems due to congenital infection
M. Dunal, A. Trzcińska, J. Siennicka
24 October 2017

1. Wstęp. 2. Budowa wirusa cytomegalii. 3. Replikacja CMV. 4. Latencja. 5. Patogeneza i formy kliniczne zakażenia. 6. Epidemiologia. 7. Zakażenie wrodzone CMV. 8. Diagnostyka zakażeń wrodzonych. 8.1. Oznaczenia serologiczne u matki. 8.2. Badanie płynu owodniowego. 8.3. USG. 8.4. Diagnostyka zakażenia wrodzonego u noworodka. 9. Profilaktyka i leczenie. 9.1. Szczepionka. 9.2. Bierna immunizacja. 9.3. Leki przeciwwirusowe. 9.4. Zapobieganie zakażeniom CMV. 10. Podsumowanie

Abstract: Human cytomegalovirus (CMV) is the most common cause of perinatal viral infections in the developed world and the leading cause of congenital infections. About 30–40% infected pregnant women transmit the infection to their fetus. The consequences of CMV infection on pregnant women are very diverse, however, due to their universality, are a serious public health problem. Therefore, the development of prevention in the form of an effective vaccine is one of the priorities of the World Health Organization. Until the vaccine is implemented, it seems very important to raise awareness about the risks associated with CMV infection. The epidemiology, clinical manifestations, prevention, diagnosis and treatment of CMV congenital infection are reviewed.

1. Introduction. 2. The structure of cytomegalovirus. 3. CMV replication. 4. Latency. 5. Pathogenesis and clinical forms of infection. 6. Epidemiology. 7. Congenital CMV infection. 8. Diagnosis of congenital infection. 8.1. Serological tests for mothers. 8.2. Examination of amniotic fluid. 8.3. USG. 8.4. Diagnosis of congenital infection in a newborn. 9. Prevention and treatment. 9.1. The vaccine. 9.2. Passive immunization. 9.3. Antivirals. 9.4. Prevention of CMV infection. 10. Summary

Autor: Postępy Mikrobiologii
No Comment
Czytaj dalej

Mikrobiologiczne ogniwa paliwowe: podstawy technologii, jej ograniczenia i potencjalne zastosowania

Microbial fuel cells: rationale, limitations and potential applications of the technology
K. Markowska, A. M. Grudniak, K. I. Wolska
24 October 2017

1. Wstęp. 2. Zasada działania i rodzaje MFC. 3. Mikroorganizmy wytwarzające elektryczność. 4. Transfer elektronów na anodę. 5. Wydajność pracy MFC. 6. Optymalizacja pracy ogniwa. 7. Wykorzystanie ogniw mikrobiologicznych. 8. Podsumowanie

Abstract: Microbial fuel cells (MFC) are devices which use electrochemically active microorganisms to generate an electrical current from a wide range of substrates. Because of the promise of sustainable energy production from organic wastes and wastewaters, this technology is of interest to many scientists. This article deseribes to rationale and limitations of this technology. The performance of MFC depends on a complex system of parameters. Apart from technical variables like the fuel cell design, mechanisms of the bioelectrochemical energy conversion decisively determine the MFC power and energy output. Current limitations make this technology inefficient in electricity generation. Therefore some researchers focus ori the ability of electrochemically active microorganisms to degrade wastes and toxic chemicals as their greatest value. Still continuous efforts are exerted to optimize performance. This article presents the most interesting
current and potential applications of microbial fuel cells are highlighted.

1. Introduction. 2. The principle of operation and types of MFC. 3. Microorganisms that produce electricity. 4. Electron transfer to the anode. 5. MFC work efficiency. 6. Optimization of the fuel cells. 7. Application of MFC. 8. Summary

Autor: Postępy Mikrobiologii
No Comment
Czytaj dalej

Budowa, regulacja i znaczenie czynników wirulencji szczepów Streptococcus agalactiae

The structure, regulation and the importance of S. agalactiae virulence factors
M. Łysakowska, M. Bigos, M. Wasiela
24 October 2017

1. Wstęp. 2. Czynniki wirulencji szczepów S. agalactiae. 3. Toksyny GBS. 3.1. β-hemolizyna/cytolizyna. 3.2. Czynnik CAMP. 4. Czynniki umożliwiające unikanie odpowiedzi układu odporności. 4.1. Otoczka. 4.2. Dysmutaza nadtlenkowa. 4.3. Peptydaza C5a. 4.4. Proteinaza serynowa. 5. Oporność na peptydy przeciwbakteryjne. 5.1. Białka wiążące penicyliny. 5.2. Fimbrie. 5.3. Antygen b. 6. Adhezja i wnikanie. 6.1. Białka wiążące fibrinogen. 6.2. Białko wiążące lamininę. 6.3. Białka bogate w powtórzenia seryny. 6.4. Immunogenna adhezyna GBS. 6.5. Białko αC (APC). 6.6. Białko IagA. 6.7. Białko powierzchniowe Rib. 7. Inne czynniki uczestniczące w patogenezie GBS. 7.1. Hialuronidaza. 7.2. Regulator transportu metioniny (MtaR). 7.3. Zdolność do wykorzystania hemu. 8. Podsumowanie

Abstract: The course of the disease caused by S. agalactiae seems to depend greatly on the presence of its diverse virulence factors. To the most important virulence factors belong: capsule, C5a peptidase, which inhibits the action of neutrophils, α-C protein, laminin binding protein, and β hemolysin typical for invasive strains. Additionally, GBS strains may present FbsA protein which protects bacteria from opsonization and fagocytosis as well as takes part in adhesion. FbsB protein facilitates invasion to epithelial cells. Some GBS strains are able to produce surface protein inactivatng chemokine, CspA. S. agalactiae strains naturally inhabit genital and digestive tract, but in certain circumstances may be responsible for varions infections, both in neonates and adults. It suggests that these bacteria are able to adapt to diffwrent environments in infected individual and proper expression of virulence factors, in response to diverse niches, makes their survival possible. The goal of this work is to present the current knowledge concerning the virulence factors of S. agalactiae and, at the same time, possible reasons why these pathogens are still causing life threatening infections, especially in neonates.

1. Introduction. 2. Virulence factors S. agalactiae strains. 3. GBS toxins. 3.1. β-haemolisin/cytolisin. 3.2. CAMP factor. 4. Factors make possible escape answer of immunity system. 4.1. Capsule. 4.2. Peroxide dysmutase. 4.3. C5a peptidase. 4.4. Serine peptidase. 5. Resistance to antibacterial peptides. 5.1. Penicilin binding proteins. 5.2. Fimbries. 5.3. Antigen b. 6. Adhesion and penetration. 6.1. Fibrinogen binding proteins. 6.2. Laminin binding proteins. 6.3. Serine reports wich proteins. 6.4. Immunogenic GBS adhesin. 6.5. αC (APC) protein. 6.6. IagA protein. 6.7. Surface Rib protein. 7. Other patogenic GBS factors. 7.1. Hialuronidase. 7.2. Metionine transport regulator (MtaR). 7.3. Heme use ability. 8. Summary

Autor: Postępy Mikrobiologii
No Comment
Czytaj dalej

Mikrosporydia: oportunistyczne patogeny ludzi

Microsporidia – opportunistic pathogens of humans
M. Bednarska
24 October 2017

1. Wstęp. 2. Pozycja systematyczna mikrosporydiów. 3. Charakterystyka spory. 4. Cykl rozwojowy mikrosporydiów. 5. Charakterystyka gatunków wykrywanych u ludzi. 5.1. Enterocytozoon bieneusi. 5.2. Encephalitozoon spp. 5.3. inne patogenne gatunki. 6. Chorobotwórczość. 7. Epidemiologia. 8. Mikrosporydioza w Polsce. 9. Drogi zarażenia i różnorodność genetyczna. 10.  Diagnostyka mikrosporydiozy. 11. Leczenie. 12. Podsumowanie

Abstract: Microsporidia are small, unicellular, and obligatory intracellular parasites of vertebrates and invertebrates. Phylogenetic analysis has placed Microsporidia with in the Fungi. They have very unusual organelles such as single polar tube, polaroplast and anchoring disc. The following genera have been associated with human infections: Enterocytozoon, Encephalitozoon, Pleistophora, Trachipleistophora, Anncaliia, Vittaforma, Brachiola, Nosema and Microsporidium. These parasites are etiological agents of diarrhea and disseminated systemic microsporidiosis in immunedeficient or immunecompetent individuals: AIDS patients, organ transplant recipients, travelers, contact lens wearers, children and elderly people. Enterocytozoon bieneusi and Encephalitozoon intestinalis are the most common causes of human infections. Microsporidian spores appear to be relatively resistant to environmental conditions, and species of microsporidia infecting humans have been identified in water sources and in free-ranging, domestic or farm animals, with a threat for waterborne, foodborne and zoonotic transmissions. Several methods are available for detection and species differentiation of microsporidia. Microscopy techniques allow the diagnosis of microsporidiosis but for genus and species determination the antigen-based and molecular methods must be used. The most effective drugs for treating microsporidiosis in humans include albendazole and fumagillin. The highly active antiretroviral therapy (HAART) reduces the prevalence of intestinal microsporidiosis in HIV-infected persons. Future studies shall focus on risk factors predisposing to microsporidiosis.

1. Introduction. 2. Taxonomy. 3. The characteristics of spores. 4. The life cycle. 5. Species infecting humans. 5.1. Enterocytozoon bieneusi. 5.2. Encephalitozoon spp. 5.3. Other pathogenic species. 6. Pathogenicity. 7. Epidemiology. 8. Microsporidiosis in Poland. 9. Transmission routes and genetic diversity. 10. Diagnostic methods. 11. Treatment. 12. Summary

Autor: Postępy Mikrobiologii
No Comment
Czytaj dalej

Szlak sygnalizacyjny cAMP u sinic

cAMP signaling pathway in Cyanobacteria
A. Domańska, M. Godlewski
24 October 2017

1. Wstęp. 2. Szlaki sygnalizacyjne cyklicznych nukleotydów u sinic. 2.1. cAMP w komórkach sinic. 2.2. Synteza cAMP u sinic. 2.3. Hydroliza cAMP u sinic. 2.4. Szlak sygnalizacyjny cGMP u sinic. 3. Biologiczna rola cAMP u sinic. 3.1. Rola szlaku cAMP w reakcji na czynniki środowiskowe i w regulacji wzrostu komórek sinic. 3.2. Regulacja transkrypcji przez szlak sygnalizacyjny cAMP u sinic.
4. Podsumowanie

Abstract: cAMP signaling pathway is a common functional pathway of signal transduction in Prokaryota and in Eukaryota. Participation of cAMP signaling pathway in the regulation of metabolic processes in cyanobacteria cells has been demonstrated by the studies showing a distinct response of these organisms to exogenous cAMP in the medium. cAMP was detected in cyanobacteria cells with changes in its level dependenting on environmental factors. In these organisms the presence of cAMP synthesis and degradation enzymes (AC and PDE, respectively) was demonstrated and genes encoding proteins involved in signal transduction pathway of cAMP were identified. Currently the sequences of 29 complete genomes of different species of cyanobacteria (and their strains) are known in which different genes connected with cAMP pathway have been identified. There include the genes ecoding AC and PDE cAMP acceptors (CRP), which are transcription factors activated by this nucleotide and genes encoding proteins playing an important role in different physiological processes whose promoters have the CRP binding sequence. These genes encode proteins involved in photosynthesis, carbon metabolism and nitrogen assimilation as well as transporter and porin proteins, protein kinases and transcription factors etc. Current studies of cAMP signaling pathway in cyanobacteria may indicate that it is not a universal pathway regulating cell functioning in the genomes of some cyanobacteria AC, PDE, CRP genes and genes whose activity is regulated by CRP were not detected. However, there is a possibility that their genomes may contain modified, not yet identified sequences encoding individual elements of the cAMP pathway.

1. Introduction. 2. Cyclic nucleotide signaling pathways in cyanobacteria. 2.1. cAMP in cyanobacteria. 2.2. cAMP synthesis in cyanobacteria. 2.3. cAMP hydrolysis in cyanobacteria. 2.4. cGMP signaling pathway in cyanobacteria. 3. Biological role of cAMP in cyanobacteria. 3.1. Role of cAMP pathway in the reaction to environmental factors and in the regulation of cell growth of cyanobacteria. 3.2. Regulation of transcription in cyanobacteria by cAMP signaling pathway. 4. Summary

Autor: Postępy Mikrobiologii
No Comment
Czytaj dalej
1 … 47 48 49 50 51 … 88

Current Issue

Current Issue

Advancements of Microbiology
Volume 63 (2024): Issue 3

Publisher

PTM

Publisher