All posts by Postępy Mikrobiologii

OSMOADAPTACJA I SYSTEMY TRANSPORTU POTASU W BAKTERIACH GRAM-UJEMNYCH

Osmoadaptation and potassium transport systems in Gram-negative bacteria
W. Małek, S. Wdowiak-Wróbel , M. Targońska, M. Kalita, S. Gnat
25 April 2018

1. Wstęp. 2. Systemy transportu K+ do komórki bakteryjnej. 2.1. System Trk. 2.2. System Ktr. 2.3. System Kdp. 2.4. System Kup. 3. Systemy wypływu K+ z komórki bakteryjnej. 4. Regulacja systemów transportu K+ do komórki bakteryjnej. 4.1. Kontrola systemów transportu K+ na poziomie ich aktywności. 4.2. Osmotyczna regulacja transportera Kdp na poziomie transkrypcji. 5. Podsumowanie

Abstract: Potassium (K+) is the major intracellular cation in bacterial cells. It plays a key role in maintaining the cell turgor, pH, adaptation to osmotic conditions, enzyme activation, and gene expression. The intracellular concentration of K+ is generally much higher than that in a growth medium and bacteria use a number of transporters and efflux pumps to maintain respective K+ concentration in cytoplasm. The best characterized K+ uptake systems in Gram-negative bacteria are: Trk, Kup, Ktr, and Kdp. Under hyperosmotic stress, in potassium-replete media at neutral and alkaline pH, the Trk system is the main K+ importer. It is a low – affinity, multiunit protein complex encoded by constitutively expressed genes that are. Under acidic conditions, when the activity of Trk is insufficient, a single component, i.e. the constitutive Kup transporter, with the affinity for K+ similar to that of the Trk system, is thought to be important. The Ktr transporter, resembling that of the Trk system, is composed of a membrane-spanning protein and a peripheral membrane-associated nucleotide – binding subunit. The Kdp-ATPase is a high affinity K+ uptake system that is expressed at very low potassium concentrations in the environment and in response to a decrease in cell turgor. Turgor, which is a signal and end the resulte of K+ import, is involved not only in the regulation of the Kdp transporter expression but also in the control of the activity of potassium uptake systems.

1. Introduction. 2. K+ uptake systems in bacterial cells. 2.1. Trk system. 2.2. Ktr system. 2.3. Kdp system. 2.4. Kup system. 3. K+ efflux systems in bacterial cells. 4. Regulation of K+ uptake systems. 4.1. Control of K+ uptake system activities. 4.2. Osmotic regulation of Kdp expression. 5. Summary

Autor: Postępy Mikrobiologii
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ZAKAŻENIA ORTOMYKSOWIRUSAMI U OSÓB Z ZABURZENIAMI ODPORNOŚCI

Infections with orthomyxoviruses in patients with immunological disorders
I. Stefańska, T. Dzieciątkowski, G. Młynarczyk
25 April 2018

1. Wstęp. 2. Ogólna budowa wirusów grypy 3. Zakażenia wirusami grypy u pacjentów z niedoborami immunologicznymi 4. Powikłania pogrypowe u osób z upośledzoną odpornością 5. Profilaktyka zakażeń wirusami grypy 6. Metody diagnostyczne stosowane w badaniu zakażeń wirusami grypy 7. Terapia zakażeń powodowanych przez ortomyksowirusy 8. Podsumowanie

Abstract: Orthomyxoviridae is a family of enveloped viruses which contain a segmented negative strand RNA genome. They cause recurrent, seasonal epidemics and occasional global pandemics with different levels of morbidity and mortality, especially in transplant recipients. Infections with influenza A and/or B viruses may lead to complications including viral pneumonia, secondary bacterial infections and graft dysfunction. The ability of influenza viruses to undergo reassortment events ensures constant generation of new strains with unpredictable degrees of pathogenicity and transmissibility. Molecular diagnostics are preferred over other diagnostic methods, if available. Influenza vaccination is well tolerated and provides protective benefit in most immunocompromised hosts; in those with contraindications to vaccination or in whom responses are predicted to be poor, antivirals may be considered. Antiviral therapy is associated with improved outcomes in transplant patients and treatment should be continued until clinical and virologic response have been documented. Resistance, particularly in patients infected with the pandemic influenza A/H1N1, should be considered and treated with an antiviral with predictable activity.

1. Introduction. 2. Morphology of othromyxoviruses. 3. Influenza virus infections in immunocompromised hosts. 4.  Post-influenza infectious complications. 5.  Prophylaxis of influenza. 6. Diagnostics in influenza infections. 7. Treatment of infection caused by othomyxoviruses. 8. Summary

Autor: Postępy Mikrobiologii
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WYKORZYSTANIE MIKROORGANIZMÓW DO USUWANIA MIKOTOKSYN Z ŻYWNOŚCI I PASZ

Using of microorganisms for mycotoxin removal from food and feed
M. Piotrowska
25 April 2018

1. Wprowadzenie. 2. Mikotoksyny – produkcja, zagrożenia zdrowotne. 3. Działania prewencyjne i usuwanie mikotoksyn z surowców. 4. Wykorzystanie mikroorganizmów do usuwania mikotoksyn. 5. Bakterie fermentacji mlekowej. 6. Drożdże Saccharomyces cerevisiae.
7. Podsumowanie

Abstract: Contamination of food and feeds with mycotoxins is a serious economic problem and primarily a phenomenon threatening human and animal health due to of their carcinogenic, nephrotoxic, genotoxic and teratogenic properties. In order to prevent mycotoxin production by fungi, special precautions should by applied, such as good agriculture practice, storing raw products under proper humidity and temperature conditions. Such actions are not always effective. Therefore, several possibilities are available for the decontamination of raw materials, including physical and chemical methods. Few of these have practical application. Biological decontamination to using microorganisms and enzymes has created new opportunities. This review discusses the available literature on the mycotoxins removal by microorganisms. Special attention was paid to Saccharomyces cerevisiae yeast and lactic acid bacteria. It seems that the application of selected strains of lactic acid bacteria and yeast in the production of fermented food and probiotic products may reduce the health risk related to human exposure to fungal toxins.

1. Introduction. 2. Mycotoxins – production, health risks. 3. Prevention and mycotoxin removal from raw materials. 4. Using of microorganisms for mycotoxins removal. 5. Lactic acid bacteria. 6. Saccharomyces cerevisiae. 7. Conclusions

Autor: Postępy Mikrobiologii
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WSPÓŁZALEŻNOŚCI MIĘDZY FLORĄ JELITOWĄ I PASOŻYTAMI GRYZONI

Interactions between intestinal microflora and parasites of rodents
K. Kowalkowska, A. Okulewicz
25 April 2018

1. Wprowadzenie. 2. Jelitowa flora bakteryjna gryzoni. 3. Badania na zwierzętach doświadczalnych. 4.Podsumowanie

Abstract: Natural intestinal microflora is a complex system of microorganisms providing homeostasis in the gastrointestinal tract of the host. Next to the bacterial commensals, there are other, larger and more hostile to the host organisms such as parasites. Laboratory rodent (mice and rats) may be contaminated with intestinal parasites, mainly pinworm species. Helminth parasites can alter the interpretation of final results. It is known that intestinal flora and parasites of animals may interact with each-other, but the nature of those relationships is not fully investigated. Unfortunately, our state of knowledge does not allow to predict the direction of those interactions, hence it seems important to carry out further research on this issue. In this work, current results of experimental studies on interactions between intestinal microflora and parasites of rodents are presented.

1. Introduction. 2. Intestinal bacterial flora of rodents. 3. Studies in experimental animals. 4. Summary

Autor: Postępy Mikrobiologii
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DIAGNOSTYKA OSTRYCH ZAKAŻEŃ GÓRNYCH DRÓG ODDECHOWYCH (GDO) – DOBÓR MATERIAŁÓW I PROBLEMY INTERPRETACYJNE ZWIĄZANE Z OBECNOŚCIĄ FLORY FIZJOLOGICZNEJ I NOSICIELSTWEM

Microbiological diagnosis of acute upper respiratory tract infections: choice of specimens and interpretation problems due to the presence of normal nasopharyngeal flora and carrier state
E. Mazur
25 April 2018
1. Wstęp. 2. Dobór materiałów do badań mikrobiologicznych w zapaleniach gdo. 3. Ostre zapalenie gardła i migdałków podniebiennych. 4. Ostre zapalenie ucha środkowego oraz jam nosowych i zatok przynosowych. 5. Materiały nieodpowiednie do diagnostyki zapaleń gdo i błędy interpretacyjne. 6. Podsumowanie
Abstract: Microbiological diagnosis can help to establish the etiological factor of acute pharyngotonsillitis, otitis media and sinusitis only of appropriate specimens have been collected. Since relevant specimens for the diagnosis of otitis media and sinusitis have to be obtained with the usage of invasive procedures, microbiological diagnosis in both diseases is not routinely recommended.
Administration of antibiotic therapy depends on clinical examination and the course of infection. The choice of antibiotic should be based on the recommendations. In Poland, the antibiotic of choice to treat acute bacterial otitis media and sinusitis is amoxicillin. In acute pharyngotonsillitis, microbiological examination is essential to confir m streptococcal etiology. It is not required if clinical examination suggests viral pharyngitis. To confirm or exclude streptococcal pharyngitis, throat swab should be obtained to perform rapid antigen detection test (RADT) or culture. Only patients with microbiologically
confirmed streptococcal pharyngitis should be treated with antibiotic. Penicillin is the drug of choice to treat streptococcal pharyngotonsillitis. Inappropriate specimens should not be the subject of microbiological examination. ;e results of microbiological examination sh ould provide physicians with interpretation, they cannot only contain the list of cultured bacteria. The discrimination should be done between etiological factors, normal flora and carrier state. Such approach can decrease unnecessary antibiotic use in the treatment of acute upper respiratory tract infections. It can also curtail the increasing antibiotic resistance among respiratory pathogens.
1. Introduction. 2. ;e choice of appropriate specimens for microbiological diagnosis of upper respiratory tract infections. 3. Acute pharyngotonsillitis. 4. Acute otitis media and sinusitis. 5. Inappropriate specimens for microbiological diagnosis of upper respiratory tract infections and interpretation errors. 6. Summar
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Advancements of Microbiology
Volume 63 (2024): Issue 1

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