Nikolai Vasilevich Sorokin and his research in botany, mycology, and microbiology at Imperial Kazan University, 1871-1901.

In 2019, the world scientific community celebrates the 110th anniversary of the death of Nikolai Vasilevich Sorokin (1846-1909), an eminent Russian biologist. On this occasion, this paper reviews the life and work of Sorokin, who was known for many important scientific breakthroughs, particularly in botany, mycology, and microbiology. Drawing upon Sorokin's publications and unpublished papers from archives, this account traces his key educational influences and the development of his research interests, research-related travels, contributions to the Russian movement in women's higher education, and his key publications, particularly his four-volume treatise on plant parasites.

Antimicrobial resistance in mollicutes: known and newly emerging mechanisms.

This review is devoted to the mechanisms of antibiotic resistance in mollicutes (class Bacilli, subclass Mollicutes), the smallest self-replicating bacteria, that can cause diseases in plants, animals and humans, and also contaminate cell cultures and vaccine preparations. Research in this area has been mainly based on the ubiquitous mollicute and the main contaminant of cell cultures, Acholeplasma laidlawii. The omics technologies applied to this and other bacteria have yielded a complex picture of responses to antimicrobials, including their removal from the cell, the acquisition of antibiotic resistance genes and mutations that potentially allow global reprogramming of many cellular processes. This review provides a brief summary of well-known resistance mechanisms that have been demonstrated in several mollicutes species and, in more detail, novel mechanisms revealed in A. laidlawii, including the least explored vesicle-mediated transfer of short RNAs with a regulatory potency. We hope that this review highlights new avenues for further studies on antimicrobial resistance in these bacteria for both a basic science and an application perspective of infection control and management in clinical and research/production settings.

Parkinson's Disease: Alpha Synuclein, Heme Oxygenase and Biotherapeutic Countermeasures.

Neurodegenerative disorders have been and remain persistent sources of enormous suffering throughout human history. The tragedy of their impact on human relationships, physical vitality, and fundamental dignity cannot be understated. Parkinson's disease (PD), one of the most common of these terrible illnesses, has a global incidence of approximately two-to-four percent of the human population, along with devastating social and economic impact. The present review analyzes aspects of PD pathophysiology that offer particularly attractive strategies for the development of improved prevention and therapy. The occurrence, symptoms, pathogenesis, and etiology of PD are considered, with focus on how the Alpha synuclein protein, which normally regulates neurotransmitter release, is aggregated by oxidative stressors into toxic inclusions, prominently including Lewy bodies and insoluble fibrils that disrupt the organization of brain areas responsible for motor control. The contribution to a progressively prooxidant tissue environment resulting from interaction between advanced glycation end products (AGEs) and their cognate receptors (RAGEs) is examined here as a significant driver of PD. This review also explores strategies currently being developed by a U.S.-Russian team that may reduce the risk and severity of PD by use of recombinant atoxic derivatives (ad) of botulinum neurotoxins (BoNT/A ad), that traffic inducers of the cytoprotective enzyme heme oxygenase to selected midbrain neurons, at which Alpha synuclein aggregation occurs. Considered together, the topic material presented here provides both researchers and clinicians with a short but concise overview of the current understanding of PD pathology and approaches to biotherapeutic (precision) countermeasures to its onset and progression.

Extracellular membrane vesicles secreted by mycoplasma Acholeplasma laidlawii PG8 are enriched in virulence proteins.

Mycoplasmas (class Mollicutes), the smallest prokaryotes capable of self-replication, as well as Archaea, Gram-positive and Gram-negative bacteria constitutively produce extracellular vesicles (EVs). However, little is known regarding the content and functions of mycoplasma vesicles. Here, we present for the first time a proteomics-based characterisation of extracellular membrane vesicles from Acholeplasma laidlawii PG8. The ubiquitous mycoplasma is widespread in nature, found in humans, animals and plants, and is the causative agent of phytomycoplasmoses and the predominant contaminant of cell cultures. Taking a proteomics approach using LC-ESI-MS/MS, we identified 97 proteins. Analysis of the identified proteins indicated that A. laidlawii-derived EVs are enriched in virulence proteins that may play critical roles in mycoplasma-induced pathogenesis. Our data will help to elucidate the functions of mycoplasma-derived EVs and to develop effective methods to control infections and contaminations of cell cultures by mycoplasmas. In the present study, we have documented for the first time the proteins in EVs secreted by mycoplasma vesicular proteins identified in this study are likely involved in the adaptation of bacteria to stressors, survival in microbial communities and pathogen-host interactions. These findings suggest that the secretion of EVs is an evolutionally conserved and universal process that occurs in organisms from the simplest wall-less bacteria to complex organisms and indicate the necessity of developing new approaches to control infects.

Adaptation of mycoplasmas to antimicrobial agents: Acholeplasma laidlawii extracellular vesicles mediate the export of ciprofloxacin and a mutant gene related to the antibiotic target.

This study demonstrated that extracellular membrane vesicles are involved with the development of resistance to fluoroquinolones by mycoplasmas (class Mollicutes). This study assessed the differences in susceptibility to ciprofloxacin among strains of Acholeplasma laidlawii PG8. The mechanisms of mycoplasma resistance to antibiotics may be associated with a mutation in a gene related to the target of quinolones, which could modulate the vesiculation level. A. laidlawii extracellular vesicles mediated the export of the nucleotide sequences of the antibiotic target gene as well as the traffic of ciprofloxacin. These results may facilitate the development of effective approaches to control mycoplasma infections, as well as the contamination of cell cultures and vaccine preparations.

Extracellular membrane vesicles and phytopathogenicity of Acholeplasma laidlawii PG8.

For the first time, the phytopathogenicity of extracellular vesicles of Acholeplasma laidlawii PG8 (a ubiquitous mycoplasma that is one of the five common species of cell culture contaminants and is a causative agent for phytomycoplasmoses) in Oryza sativa L. plants was studied. Data on the ability of extracellular vesicles of Acholeplasma laidlawii PG8 to penetrate from the nutrient medium into overground parts of Oryza sativa L. through the root system and to cause alterations in ultrastructural organization of the plants were presented. As a result of the analysis of ultrathin leaf sections of plants grown in medium with A. laidlawii PG8 vesicles, we detected significant changes in tissue ultrastructure characteristic to oxidative stress in plants as well as their cultivation along with bacterial cells. The presence of nucleotide sequences of some mycoplasma genes within extracellular vesicles of Acholeplasma laidlawii PG8 allowed a possibility to use PCR (with the following sequencing) to perform differential detection of cells and bacterial vesicles in samples under study. The obtained data may suggest the ability of extracellular vesicles of the mycoplasma to display in plants the features of infection from the viewpoint of virulence criteria--invasivity, infectivity--and toxigenicity--and to favor to bacterial phytopathogenicity.

Unadapted and adapted to starvation Acholeplasma laidlawii cells induce different responses of Oryza sativa, as determined by proteome analysis.

For the first time, we studied the phytopathogenicity toward Oryza sativa L. of unadapted and adapted to unfavorable environment (starvation) cells of Acholeplasma laidlawii PG8--ubiquitous mycoplasma found in the soil, waste waters, tissues of the highest eukaryotes and being the basic contaminant of cell cultures and a causative agent of phytomycoplasmoses. The features of morphology, ultrastructural organization and proteomes of unadapted and adapted cells of the mycoplasma and infected plants were presented. Using 2D-DIGE and MS, 43 proteins of O. sativa L. that were differentially expressed in the leaves of plants cultivated in media with A. laidlawii PG8 were identified. The qualitative and quantitative responses of the plant proteome toward adapted and unadapted mycoplasma cells differed. That may be explained by differences in the virulence of the corresponding bacterial cells. Using 2D-DIGE and MS, 82 proteins that were differentially expressed in adapted and unadapted mycoplasma cells were detected. In adapted cells of the mycoplasma, in comparison with unadapted ones, a significant increase in the expression of PNPase--a global regulator of virulence in phytopathogenic bacteria occurred; there was also decreased expression of 40 proteins including 14 involved in bacterial virulence and the expression of 31 proteins including 5 involved in virulence was not detected. We propose that differences in the phytopathogenicity of adapted and unadapted A. laidlawii PG8 cells may be related to features of their proteomes and membrane vesicles.

Extracellular vesicles derived from Acholeplasma laidlawii PG8.

Extracellular vesicle production is believed to be a ubiquitous process in bacteria, but the data on such a process in Mollicutes are absent. We report the isolation of ultramicroforms - extracellular vesicles from supernatants of Acholeplasma laidlawii PG8 (ubiquitous mycoplasma; the main contaminant of cell culture). Considering sizes, morphology, and ultrastructural organization, the ultramicroforms of A. laidlawii PG8 are similar to membrane vesicles of Gram-positive and Gram-negative bacteria. We demonstrate that A. laidlawii PG8 vesicles contain genetic material and proteins, and are mutagenic to lymphocytes of human peripheral blood. We show that Mycoplasma gallisepticum S6, the other mycoplasma, also produce similar structures, which suggests that shedding of the vesicles might be the common phenomenon in Mollicutes. We found that the action of stress conditions results in the intensive formation of ultramicroforms in mycoplasmas. The role of vesicular formation in mycoplasmas remains to be studied.

Atomic force microscopy analysis of DNA extracted from the vegetative cells and the viable, but nonculturable, cells of two mycoplasmas (Acholeplasma laidlawii PG8 and Mycoplasma hominis PG37).

This article reports on a study of some characteristics of DNA extracted from the vegetative and viable, but nonculturable (VBNC), cells of two mycoplasma species (Acholeplasma laidlawii PG8 and Mycoplasma hominis PG37) using atomic force microscopy (AFM). DNA images were obtained by operating the AFM microscope in the tapping mode. It was found that DNA from the VBNC forms of M. hominis PG37 has decreased sizes (height: 0.177 +/- 0.026 nm vs. 0.391 +/- 0.041 nm for the vegetative forms, and width: 1.92 +/- 0.099 vs. 2.17 +/- 0.156 nm for the vegetative forms) in comparison to DNA from the vegetative forms of the mycoplasma. In the case of DNA from the A. laidlawii PG8 VBNC forms, we detected a decrease in width (1.506 +/- 0.076 nm vs. 1.898 +/- 0.117 nm for the vegetative forms), but an increase in height (0.641 +/- 0.068 nm vs. 0.255 +/- 0.010 nm for the vegetative forms) of the molecule. Analyzing the obtained results, one can speculate on some similarities in the physical-chemical properties of DNA from M. hominis PG37 and M. gallisepticum S6. In turn, this implies some general mechanisms of adaptation to a severe environment.

Phytopathogenicity of avian mycoplasma Mycoplasma gallisepticum S6: morphologic and ultracytostructural changes in plants infected with the vegetative forms and the viable but nonculturable forms of the bacterium.

The data obtained in this study proved that Mycoplasma gallisepticum S6 known as avian pathogen had a phytopathogenic potential. The vegetative forms and the viable but nonculturable (VBNC) forms of this mycoplasma could infect the plants via an assemblage of rootlets, invade different tissues, persist there and cause destructive events characteristic to phytomycoplasmoses. In comparison with the vegetative forms, the VBNC forms induced more prominent destructive changes. This phenomenon might be connected to increasing expression of proteins responsible for virulence in the bacterial cells. The fact that M. gallisepticum S6 could demonstrate virulent features (infectivity, invasiveness, persistence and toxigenicity) in regard to plants seems to require a development of new ways for controlling phytomycoplasmoses taking into account the probable presence of asymptomatic carriers of this bacterium.

Atomic force microscopy investigation of DNA extracted from the vegetative forms and the viable but nonculturable forms of Mycoplasma gallisepticum S6.

Recent studies show that mycoplasmas have various programs of life. This means that changes in morphology and genome expression may occur once the environment of these microorganisms becomes extremely altered. In this article, we report on changes in the DNA molecule obtained from the vegetative forms and the viable but nonculturable (VBNC) forms of Mycoplasma gallisepticum S6. Atomic force microscopy studies show that the above-mentioned forms of the mycoplasma have different values of DNA parameters (height: 0.461 +/- 0.141 and 0.236 +/- 0.069 nm; width: 2.221 +/- 0.286 and 1.291 +/- 0.705 nm for the vegetative and the VBNC forms, respectively). We suppose that the observed phenomenon may be connected with the process of adaptation of these bacteria to severe environments.

The pattern of acute myocardial infarction in people with opportunistic infections.

First comparative analysis for some hemocoagulation reactions, immune state of acute myocardial infarction has been done in two groups of patients - with mycoplasma infections and without one. Postinfarction complications in the groups were observed. Atherosclerotic plaques of the patients were also studied on a presence of mycoplasmas and a content of strontium and zinc. A tendency to a mild pattern of acute myocardial infarction was observed in patients with mycoplasma infections. The role of mycoplasmas in atherogenesis and acute myocardial infarction is discussed.

Acholeplasma laidlawii PG8 culture adapted to unfavorable growth conditions shows an expressed phytopathogenicity.

Mycoplasmas are the smallest, self-replicating, prokaryotic organisms with avid biochemical potential and spreading in higher eukaryotes in nature. In this study, Acholeplasma laidlawii PG8 cells were cultivated on a deficient medium for 480 days resulting in a mycoplasma culture that was adapted in vitro to unfavorable growth conditions. Cells that survive this condition had decreased sizes (about 0.2 microm) and increased phytopathogenicity. This resulted in more frequent appearance of various morphological alterations when plants of vinca (Vinca minor L.) were infected by adapted mycoplasma cells. The increasing pathogenicity was accompanied by changes in genome expression in these adapted cells. Further studies are needed to explore the exact mechanisms that permit adaptation to unfavorable growth conditions and changes in phytopathogenic potential.

Significant delay of lethal outcome in cancer patients due to peroral administration of Bacillus oligonitrophilus KU-1.

Treatment of cancer patients remains a serious medical problem and the development of alternative treatment strategies is therefore of great importance. In this connection, we developed a new bacterial-based, anticancer method. Ten cancer patients (three males, seven females) were involved in this study. Bacterial suspension of stationary phase Bacillus oligonitrophilus KU-1 was used as a remedy for peroral administration. In five patients, side effects (sicchasia, slight blood, and intracranial pressure gain) were detected, but all patients showed significant delay of lethal outcome without serious side effects. In conclusion, the suggested method was, in our opinion, a good alternative to conventional chemo- and radiotherapy techniques. In order to evaluate its efficiency for various tumors, a double-blind, placebo-controlled, multicenter study is needed.

Effects of type II pyrethroids on Daphnia magna: dose and temperature dependences.

Environmental contamination with various insecticides remains an actual problem. In this connection, investigation of toxicologic hazard of insecticides is essential. In this work, effects of the type II pyrethroids (fenvalerate, cypermethrin and deltamethrin) on Daphnia magna were determined. It was found for the first time that not only low doses (up to 10(-12) M) of the above-mentioned chemicals but also extremely low doses (up to 10(-29) M) showed toxicological action on the invertebrates both at optimal (23 +/- 0.5 degrees C) and increased (28 +/- 0.5 degrees C) temperature. At higher temperature, toxic effects were more pronounced.

Antitumor features of Bacillus oligonitrophilus KU-1 strain.

Chemotherapy and radiotherapy remain mostly palliative methods for metastatic cancer treatment. Limitations in efficacy and safety of established treatments continue to underline the need for improved treatments for malignancy. Results with some probiotics with antitumor activity have been promising. Here, we report that oral reception of Bacillus oligonitrophilus KU-1 resulted in the prolongation of lives in cancer patients with terminal prognosis and stabilization of cancer growth. The theoretical basis for the phenomena observed is discussed.

Variability of the Vaa cytoadhesin genes in clinical isolates of Mycoplasma hominis.

The Mycoplasma hominis vaa gene encodes a highly variable surface antigen involved in adhesion to host cells. We studied 15 clinical isolates of Mycoplasma hominis with three types of the vaa gene. These vaa versions determine various forms of Vaa protein, which are characterized by different quantity and structure of homologous replaceable cassettes. Each cassette contains heptad repeats and sites for adherence. The differences on single nucleotides were observed in the primary sequences of the homologous modules of the vaa gene. A high frequency of nucleotide replacements in V module of the vaa gene (first and/or second position in codon) was determined. This region with various clusters of direct and indirect repeats of nucleotide sequences is incorporated into the area of the vaa gene. Amino-acid sequences corresponding to the hyper-variable region of the vaa gene are associated with the sections of coiled-coils and loops of Vaa. These bacterial regions involved in interaction with the host cell membranes could yield useful indications for more insights into the mechanism of mycoplasma persistence in humans.