Volumen 60 (2021): Heft 2 (January 2021)

The ability to from biofilms, which is a common feature in Salmonella serovars, is the main cause of persistent infections and permanent contamination in both clinical and industrial systems. Because the biofilm structures are significantly more resistant to environmental stress conditions than the planktonic forms of bacteria, it is often impossible to remove them through conventional disinfection or sterilization practices. Therefore, it has become necessary to develop effective strategies in combating biofilms, which are defined as the dominant form of microbial life. To achieve this goal, it is necessary to understand the genetic regulatory mechanisms that control the transition from planktonic form to the biofilm form and the related changes in gene expression. In this review, the current state of knowledge regarding gene regulation systems that affect the biofilm formation in Salmonella, has been summarized and discussed.

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the third, following SARS-CoV (Severe Acute Respiratory Syndrome Coronavirus) and Middle East Respiratory Syndrome-CoV (MERS), zoonotic coronavirus that has crossed the species barrier in XXI century resulting in the development of serious human infection termed COVID-19 (coronavirus disease-19). However, there are still many unanswered questions about its transmissibility and pathogenesis, what impelled us to gather the most recent facts about the nature of coronaviruses. At first we introduced the basic information about coronavirus taxonomy, structure, and replication process to create the basis for more advanced consideration. We also put across the molecular basis of the strategy used by coronaviruses to cross the species barrier. In the following part of this review we focused on the interactions between the virus and the receptor on the host cell, as this stage is the critical process determining the species and tissue tropism, as well as clinical course of infection. The special attention was paid to the cellular receptors interaction with S protein of different CoVs (dipeptidyl peptidase IV and angiotensin-converting enzyme 2) as well as the cellular proteases involved in proteolysis of this protein. These factors determine the virus entry and replication, thus even the fine quantitative or qualitative difference in their expression may be crucial for outcome of infection. We also considered the host immune response and viral evasion mechanisms which would be helpful to understand COVID-19 pathogenesis. We wish the information provided by this review may be helpful to understand virus biology and to develop efficient therapeutic and preventive strategies.

Bacterial glycoconjugates are widespread and have diverse biological functions. Multiple bacterial glycoproteins are involved in adhesion, invasion or evasion of host defense mechanisms. A range of glycosylation pathways has recently been an object of intense research. Their activity is based on the glycosyltransferases – enzymes that transfer sugar moieties directly to the acceptor protein (sequential glycosylation) or to a lipid carrier from which the glycan is transferred by an oligosaccharyltransferase onto the target protein (en-bloc glycosylation). Successful implementation of complete glycosylation systems in Escherichia coli cells resulted in rapid development of bacterial glycoengineering. Oligosaccharyltransferases are characterized by a broad substrate specificity which may be exploited to produce glycoconjugate vaccines.

It is well known, that vaginal microbiota is dominated by Lactobacillus genus. These bacteria protect a vaginal microenvironment against the invading pathogens. The presence of Lactobacillus communities was already confirmed in an upper female reproductive system, as well as in the male reproductive system and semen. In this paper we present the current state of knowledge about the influence of the Lactobacillus species on female and male fertility. We also discuss the possible role of the reproductive system microbiota in an idiopathic infertility, and the association between Lactobacillus species and effectiveness of assisted reproductive techniques. Further research on the relationship between the reproductive system microbiota and human fertility is needed.

Helicobacter pylori is a Gram-negative, rod-shaped bacterium with an ability to colonise the gastric pylorus. It is estimated that more than half of the human population may be carriers of this pathogen. Unfortunately, the collected data concerning H. pylori infections is inaccurate as the symptoms occur only in 20% of people infected. The presence of the bacteria may lead to inflammation, stomach ulcers, or even cancer. In the cases of confirmed infection, the treatment usually involves a so called “triple therapy” with a proton-pump inhibitor and antibiotics. However, a decrease in the effectiveness of this therapy is observed as a result of increasing antibiotic resistance in bacteria. New solutions are being researched that could both help in the treatment of H. pylori infections and prevent the spread of the pathogen. Numerous scientific studies confirm that the use of plant-based products can be a good addition to the treatment of various infections. Phytotherapy is a science-based medical practice that uses the knowledge about active compounds naturally occurring in plants, in order to improve overall health. From existing research, it is known that the consumption of certain plant-derived products, for example olive oil and green tea, can lead to H. pylori eradication. On the other hand, licorice can be used to support the classic treatment method by increasing the eradication rate of the pathogen. Plants with anti-H. pylori properties include: cinnamon, cranberry, oregano, aloe vera and many others. The aim of this work is to review literature that is focused on a potential use of phytotherapy to support the treatment, combat, or prevent infections caused by H. pylori.