scholarly journals Spirochete Flagella and Motility

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 550 ◽  
Author(s):  
Shuichi Nakamura
Keyword(s):  
Lyme Disease ◽  
Molecular Basis ◽  
High Efficiency ◽  
Current Knowledge ◽  
Periplasmic Space ◽  
Swine Dysentery ◽  
Micro Robot ◽  
Host Pathogen ◽  
Causative Agents ◽  
Periplasmic Flagella

Spirochetes can be distinguished from other flagellated bacteria by their long, thin, spiral (or wavy) cell bodies and endoflagella that reside within the periplasmic space, designated as periplasmic flagella (PFs). Some members of the spirochetes are pathogenic, including the causative agents of syphilis, Lyme disease, swine dysentery, and leptospirosis. Furthermore, their unique morphologies have attracted attention of structural biologists; however, the underlying physics of viscoelasticity-dependent spirochetal motility is a longstanding mystery. Elucidating the molecular basis of spirochetal invasion and interaction with hosts, resulting in the appearance of symptoms or the generation of asymptomatic reservoirs, will lead to a deeper understanding of host–pathogen relationships and the development of antimicrobials. Moreover, the mechanism of propulsion in fluids or on surfaces by the rotation of PFs within the narrow periplasmic space could be a designing base for an autonomously driving micro-robot with high efficiency. This review describes diverse morphology and motility observed among the spirochetes and further summarizes the current knowledge on their mechanisms and relations to pathogenicity, mainly from the standpoint of experimental biophysics.

scholarly journals Molecular Mechanisms of Borrelia burgdorferi Phagocytosis and Intracellular Processing by Human Macrophages

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 567
Author(s):  
Philipp Woitzik ◽  
Stefan Linder
Keyword(s):  
Immune System ◽  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Human Macrophages ◽  
Sequence Of Events ◽  
Intracellular Processing ◽  
Open Questions ◽  
Causative Agents

Lyme disease is the most common vector-borne illness in North America and Europe. Its causative agents are spirochetes of the Borrelia burgdorferi sensu latu complex. Infection with borreliae can manifest in different tissues, most commonly in the skin and joints, but in severe cases also in the nervous systems and the heart. The immune response of the host is a crucial factor for preventing the development or progression of Lyme disease. Macrophages are part of the innate immune system and thus one of the first cells to encounter infecting borreliae. As professional phagocytes, they are capable of recognition, uptake, intracellular processing and final elimination of borreliae. This sequence of events involves the initial capture and internalization by actin-rich cellular protrusions, filopodia and coiling pseudopods. Uptake into phagosomes is followed by compaction of the elongated spirochetes and degradation in mature phagolysosomes. In this review, we discuss the current knowledge about the processes and molecular mechanisms involved in recognition, capturing, uptake and intracellular processing of Borrelia by human macrophages. Moreover, we highlight interactions between macrophages and other cells of the immune system during these processes and point out open questions in the intracellular processing of borreliae, which include potential escape strategies of Borrelia.

scholarly journals Search for Promising Strains of Probiotic Microbiota Isolated from Different Biotopes of Healthy Cats for Use in the Control of Surgical Infections

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 667
Author(s):  
Pavel Rudenko ◽  
Yuriy Vatnikov ◽  
Nadezhda Sachivkina ◽  
Andrei Rudenko ◽  
Evgeny Kulikov ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
High Efficiency ◽  
Biological Marker ◽  
High Sensitivity ◽  
Antagonistic Activity ◽  
Adhesive Properties ◽  
Surgical Infection ◽  
Surgical Infections ◽  
Causative Agents ◽  
Inflammatory Processes

Despite the introduction of modern methods of treatment, the creation of new generations of antibacterial agents, and the constant improvement of aseptic and antiseptic methods, the treatment of purulent–inflammatory processes remains one of the most complex and urgent problems in veterinary practice. The article presents the results of the isolation of indigenous microbiota from various biotopes of healthy cats, as well as the study of their biological marker properties for the selection of the most optimal strains in probiotic medicines for the control of surgical infections. It was demonstrated that isolated cultures of bifidobacteria and lactobacilli, which we isolated, revealed high sensitivity to antibiotics of the β-lactam group (excepting L. acidophilus No. 24, L. plantarum “Victoria” No. 22, L. rhamnosus No. 5, L. rhamnosus No. 20, and L. rhamnosus No. 26, which showed a significant variability in sensitivity to antibacterial drugs of this group, indicating the great potential of these microorganisms) and resistance to aminoglycosides, lincosamides, and fluoroquinolones (with the exception of gatifloxacin, which showed high efficiency in relation to all lactic acid microorganisms). The adhesive properties of the isolated lactobacteria and bifidobacteria were variable, even within the same species. It was found that the B. adolescentis No. 23 strain of the Bifidobacterium genus, as well as the L. plantarum No. 8, L. plantarum “Victoria” No. 22, L. rhamnosus No. 6, L. rhamnosus No. 26, L. acidophilus No. 12, and L. acidophilus No. 24 strains of the Lactobacillus genus had the highest adhesive activity. Thus, when conducting a detailed analysis of the biological marker properties of candidate cultures (determining their sensitivity to antimicrobial agents, studying the adhesive properties, and antagonistic activity in relation to causative agents of surgical infection in cats), it was found that the most promising are L. plantarum “Victoria” No. 22, L. rhamnosus No. 26, and L. acidophilus No. 24.

scholarly journals Lineage Switching in Acute Leukemias: A Consequence of Stem Cell Plasticity?

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Elisa Dorantes-Acosta ◽  
Rosana Pelayo
Keyword(s):  
Cell Fate ◽  
High Efficiency ◽  
Current Knowledge ◽  
Lymphoblastic Leukemia ◽  
Survival Rates ◽  
Cell Lineage ◽  
Leukemic Cells ◽  
Acute Leukemias ◽  
Cell Fate Decisions ◽  
Lineage Switch

Acute leukemias are the most common cancer in childhood and characterized by the uncontrolled production of hematopoietic precursor cells of the lymphoid or myeloid series within the bone marrow. Even when a relatively high efficiency of therapeutic agents has increased the overall survival rates in the last years, factors such as cell lineage switching and the rise of mixed lineages at relapses often change the prognosis of the illness. During lineage switching, conversions from lymphoblastic leukemia to myeloid leukemia, or vice versa, are recorded. The central mechanisms involved in these phenomena remain undefined, but recent studies suggest that lineage commitment of plastic hematopoietic progenitors may be multidirectional and reversible upon specific signals provided by both intrinsic and environmental cues. In this paper, we focus on the current knowledge about cell heterogeneity and the lineage switch resulting from leukemic cells plasticity. A number of hypothetical mechanisms that may inspire changes in cell fate decisions are highlighted. Understanding the plasticity of leukemia initiating cells might be fundamental to unravel the pathogenesis of lineage switch in acute leukemias and will illuminate the importance of a flexible hematopoietic development.

scholarly journals The Borrelia burgdorferi 37-Kilodalton Immunoblot Band (P37) Used in Serodiagnosis of Early Lyme Disease Is the flaA Gene Product

1999 ◽  
Vol 37 (3) ◽  
pp. 548-552 ◽  
Author(s):  
Robert D. Gilmore ◽  
Rendi L. Murphree ◽  
Angela M. James ◽  
Sarah A. Sullivan ◽  
Barbara J. B. Johnson
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Genomic Library ◽  
Disease Patient ◽  
Humoral Response ◽  
Immunoglobulin M ◽  
Leader Peptide ◽  
Serum Samples ◽  
Present Generation ◽  
Periplasmic Flagella

The 37-kDa protein (P37) of Borrelia burgdorferi is an antigen that elicits an early immunoglobulin M (IgM) antibody response in Lyme disease patients. The P37 gene was cloned from aB. burgdorferi genomic library by screening with antibody from a Lyme disease patient who had developed a prominent humoral response to the P37 antigen. DNA sequence analysis of this clone revealed the identity of P37 to be FlaA, an outer sheath protein of the periplasmic flagella. Recombinant P37 expression was accomplished inEscherichia coli by using a gene construct with the leader peptide deleted and fused to a 38-kDa E. coli protein. The recombinant antigen was reactive in IgM immunoblots using serum samples from patients clinically diagnosed with early Lyme disease that had been scored positive for B. burgdorferi anti-P37 reactivity. Lyme disease patient samples serologically negative for theB. burgdorferi P37 protein did not react with the recombinant. Recombinant P37 may be a useful component of a set of defined antigens for the serodiagnosis of early Lyme disease. This protein can be utilized as a marker in diagnostic immunoblots, aiding in the standardization of the present generation of IgM serologic tests.

scholarly journals Dangerous Duplicity: The Dual Functions of Casein Kinase 1in Parasite Biology and Host Subversion

2021 ◽  
Vol 11 ◽  
Author(s):  
Najma Rachidi ◽  
Uwe Knippschild ◽  
Gerald F. Späth
Keyword(s):  
Current Knowledge ◽  
Family Members ◽  
Casein Kinase ◽  
Biological Processes ◽  
Casein Kinase 1 ◽  
Parasite Survival ◽  
Host Pathogen ◽  
Parasite Biology ◽  
Antimicrobial Interventions

Casein Kinase 1 (CK1) family members are serine/threonine protein kinases that are involved in many biological processes and highly conserved in eukaryotes from protozoan to humans. Even though pathogens exploit host CK1 signaling pathways to survive, the role of CK1 in infectious diseases and host/pathogen interaction is less well characterized compared to other diseases, such as cancer or neurodegenerative diseases. Here we present the current knowledge on CK1 in protozoan parasites highlighting their essential role for parasite survival and their importance for host-pathogen interactions. We also discuss how the dual requirement of CK1 family members for parasite biological processes and host subversion could be exploited to identify novel antimicrobial interventions.

Interactions between Neisseria meningitidis and human cells that promote colonisation and disease

2004 ◽  
Vol 6 (14) ◽  
pp. 1-14 ◽  
Author(s):  
Anne Corbett ◽  
Rachel Exley ◽  
Sandrine Bourdoulous ◽  
Christoph M. Tang
Keyword(s):  
Cerebrospinal Fluid ◽  
Bacterial Meningitis ◽  
Neisseria Meningitidis ◽  
Human Cell ◽  
Molecular Basis ◽  
Cell Types ◽  
Cellular Level ◽  
Human Cells ◽  
Healthy Individuals ◽  
Host Pathogen

Neisseria meningitidis is the leading cause of bacterial meningitis, a potentially fatal condition that particularly affects children. Multiple steps are involved during the pathogenesis of infection, including the colonisation of healthy individuals and invasion of the bacterium into the cerebrospinal fluid. The bacterium is capable of adhering to, and entering into, a range of human cell types, which facilitates its ability to cause disease. This article summarises the molecular basis of host–pathogen interactions at the cellular level during meningococcal carriage and disease.

scholarly journals Role of the PE/PPE Family in Host–Pathogen Interactions and Prospects for Anti-Tuberculosis Vaccine and Diagnostic Tool Design

2020 ◽  
Vol 10 ◽  
Author(s):  
Jianing Qian ◽  
Run Chen ◽  
Honghai Wang ◽  
Xuelian Zhang
Keyword(s):  
Cell Fate ◽  
Current Knowledge ◽  
Cell Interaction ◽  
Key Factors ◽  
Host Pathogen Interactions ◽  
Future Directions ◽  
Host Pathogen ◽  
Protein Research ◽  
Slow Growing

The pe/ppe genes are found in pathogenic, slow-growing Mycobacterium tuberculosis and other M. tuberculosis complex (MTBC) species. These genes are considered key factors in host-pathogen interactions. Although the function of most PE/PPE family proteins remains unclear, accumulating evidence suggests that this family is involved in M. tuberculosis infection. Here, we review the role of PE/PPE proteins, which are believed to be linked to the ESX system function. Further, we highlight the reported functions of PE/PPE proteins, including their roles in host cell interaction, immune response regulation, and cell fate determination during complex host-pathogen processes. Finally, we propose future directions for PE/PPE protein research and consider how the current knowledge might be applied to design more specific diagnostics and effective vaccines for global tuberculosis control.

scholarly journals Modulation of hydrolytic profiles of cell-bound and cell-free exoenzymes in Antarctic marine bacterial isolates

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Vincenzo Manna ◽  
Paola Del Negro ◽  
Mauro Celussi
Keyword(s):  
Organic Matter ◽  
Ross Sea ◽  
Current Knowledge ◽  
Hydrolysis Product ◽  
Foraging Strategies ◽  
Periplasmic Space ◽  
Bacterial Isolates ◽  
Bacterial Strains ◽  
Produce Cell ◽  
Hydrolytic Activities

Microbial degradation of high molecular weight organic matter in the marine environment is dependent on the synthesis and activity of hydrolytic exoenzymes. These can be found both associated to the cell (i.e., attached to cell-wall or in the periplasmic space) and cell-free, dissolved in the surrounding waters. Recent evidences suggest that exoenzymes location is linked to different foraging strategies. ‘Selfish’ bacteria use cell-bound enzymes to obtain large oligomers which are then further degraded in the confined periplasmic space, whereas cell-free enzymes are thought to be advantageous for particle-attached prokaryotes, consequently ‘sharing’ the hydrolysis product with other members of the degrading consortium. We examined whether different bacterial isolates exhibit different exoenzymatic activity profiles when exposed to different growth condition. Seven bacterial strains, isolated from the Ross Sea, were screened for the production of β-glucosidase, alkaline-phosphatase, lipase, chitinase and leucine aminopeptidase, assaying the hydrolysis rates of both cell-bound and cell-free exoenzymatic fractions. Furthermore, to test whether bacteria growing on particles are more prone to produce cell-free exoenzymes, we set up a controlled experiment, amending one of the bacterial isolates with phytodetritus, in order to promote the colonization of aggregates. Cell specific hydrolytic rates were highly variable and different isolates expressed different dominant hydrolytic activities. These results demonstrate a specialization for different substrates in different bacteria, further suggesting that some of the tested isolates may have an intrinsic potential to copiously produce cell-free exoenzymes. Moreover, our results suggest that this specialization is not strictly genetically determined but varies according to growth conditions. The experiment performed with phytodetrital particles highlighted an increasing contribution of the dissolved exoenzymatic activity in samples bearing aggregates and associated bacteria. Also, the tested isolate further modulated its hydrolytic machinery, expressing a different enzymatic profile when exposed to phytodetrital particles. The continuation of these experimental activities, testing the response of different bacterial isolates to different substrates, will help to determine the conditions under which different hydrolysis patterns develop, deepening the current knowledge on the organic matter cycling in the ocean.

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