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Sheng Wu Gong Cheng Xue Bao = Chinese... Sep 2020Mycoplasma hyopneumoniae is the pathogen of porcine enzootic pneumonia (PEP). Due to difficulties in studying the pathogenesis of M. hyopneumoniae for blockage on the... (Review)
Review
Mycoplasma hyopneumoniae is the pathogen of porcine enzootic pneumonia (PEP). Due to difficulties in studying the pathogenesis of M. hyopneumoniae for blockage on the establishment of gene operation platform and immature animal model, mycoplasmologists still make progress in understanding the interaction between M. hyopneumoniae and host. In this paper, we review the adhesion and damage of M. hyopneumoniae to host cells, the inflammatory response and immune response of host stimulated by M. hyopneumoniae. Meanwhile, we propose research directions of the pathogenesis of M. hyopneumoniae in the future. This review can provide references for the follow-up study on the interaction between M. hyopneumoniae and host, and provide theoretical basis for effective vaccine and drug development.
Topics: Animals; Follow-Up Studies; Mycoplasma hyopneumoniae; Pneumonia of Swine, Mycoplasmal; Swine
PubMed: 33164453
DOI: 10.13345/j.cjb.200050 -
Frontiers in Cellular and Infection... 2023Mycoplasmas, the smallest known self-replicating organisms, possess a simple structure, lack a cell wall, and have limited metabolic pathways. They are responsible for... (Review)
Review
Mycoplasmas, the smallest known self-replicating organisms, possess a simple structure, lack a cell wall, and have limited metabolic pathways. They are responsible for causing acute or chronic infections in humans and animals, with a significant number of species exhibiting pathogenicity. Although the innate and adaptive immune responses can effectively combat this pathogen, mycoplasmas are capable of persisting in the host, indicating that the immune system fails to eliminate them completely. Recent studies have shed light on the intricate and sophisticated defense mechanisms developed by mycoplasmas during their long-term co-evolution with the host. These evasion strategies encompass various tactics, including invasion, biofilm formation, and modulation of immune responses, such as inhibition of immune cell activity, suppression of immune cell function, and resistance against immune molecules. Additionally, antigen variation and molecular mimicry are also crucial immune evasion strategies. This review comprehensively summarizes the evasion mechanisms employed by mycoplasmas, providing valuable insights into the pathogenesis of mycoplasma infections.
Topics: Animals; Humans; Immune Evasion; Mycoplasma; Antigenic Variation; Mycoplasma Infections; Cell Wall
PubMed: 37719671
DOI: 10.3389/fcimb.2023.1247182 -
Current Issues in Molecular Biology 2018The class Mollicutes (trivial name "mycoplasma") is composed of wall-less bacteria with reduced genomes whose evolution was long thought to be only driven by gene... (Review)
Review
The class Mollicutes (trivial name "mycoplasma") is composed of wall-less bacteria with reduced genomes whose evolution was long thought to be only driven by gene losses. Recent evidences of massive horizontal gene transfer (HGT) within and across species provided a new frame to understand the successful adaptation of these minimal bacteria to a broad range of hosts. Mobile genetic elements are being identified in a growing number of mycoplasma species, but integrative and conjugative elements (ICEs) are emerging as pivotal in HGT. While sharing common traits with other bacterial ICEs, such as their chromosomal integration and the use of a type IV secretion system to mediate horizontal dissemination, mycoplasma ICEs (MICEs) revealed unique features: their chromosomal integration is totally random and driven by a DDE recombinase related to the Mutator-like superfamily. Mycoplasma conjugation is not restricted to ICE transmission, but also involves the transfer of large chromosomal fragments that generates progenies with mosaic genomes, nearly every position of chromosome being mobile. Mycoplasmas have thus developed efficient ways to gain access to a considerable reservoir of genetic resources distributed among a vast number of species expanding the concept of minimal cell to the broader context of flowing information.
Topics: Chromosomes, Bacterial; Conjugation, Genetic; Evolution, Molecular; Gene Transfer, Horizontal; Mycoplasma; Response Elements; Tenericutes
PubMed: 29648541
DOI: 10.21775/cimb.029.003 -
Biology Direct Jan 2016The length of a protein sequence is largely determined by its function. In certain species, it may be also affected by additional factors, such as growth temperature or...
BACKGROUND
The length of a protein sequence is largely determined by its function. In certain species, it may be also affected by additional factors, such as growth temperature or acidity. In 2002, it was shown that in the bacterium Escherichia coli and in the archaeon Archaeoglobus fulgidus, protein sequences with no homologs were, on average, shorter than those with homologs (BMC Evol Biol 2:20, 2002). It is now generally accepted that in bacterial and archaeal genomes the distributions of protein length are different between sequences with and without homologs. In this study, we examine this postulate by conducting a comprehensive analysis of all annotated prokaryotic genomes and by focusing on certain exceptions.
RESULTS
We compared the distribution of lengths of "having homologs proteins" (HHPs) and "non-having homologs proteins" (orphans or ORFans) in all currently completely sequenced and COG-annotated prokaryotic genomes. As expected, the HHPs and ORFans have strikingly different length distributions in almost all genomes. As previously established, the HHPs, indeed are, on average, longer than the ORFans, and the length distributions for the ORFans have a relatively narrow peak, in contrast to the HHPs, whose lengths spread over a wider range of values. However, about thirty genomes do not obey these rules. Practically all genomes of Mycoplasma and Ureaplasma have atypical ORFans distributions, with the mean lengths of ORFan larger than the mean lengths of HHPs. These genera constitute over 80 % of atypical genomes.
CONCLUSIONS
We confirmed on a ubiquitous set of genomes that the previous observation of HHPs and ORFans have different gene length distributions. We also showed that Mycoplasmataceae genomes have very distinctive distributions of ORFans lengths. We offer several possible biological explanations of this phenomenon, such as an adaptation to Mycoplasmataceae's ecological niche, specifically its "quiet" co-existence with host organisms, resulting in long ABC transporters.
Topics: Bacterial Proteins; Genome, Bacterial; Mycoplasmataceae; Open Reading Frames
PubMed: 26747447
DOI: 10.1186/s13062-015-0104-3 -
BMC Microbiology Jun 2020Bats are hosts for a variety of microorganisms, however, little is known about the presence of Chlamydiales and hemotropic mycoplasmas. This study investigated 475...
BACKGROUND
Bats are hosts for a variety of microorganisms, however, little is known about the presence of Chlamydiales and hemotropic mycoplasmas. This study investigated 475 captive and free-living bats from Switzerland, Germany, and Costa Rica for Chlamydiales and hemotropic mycoplasmas by PCR to determine the prevalence and phylogeny of these organisms.
RESULTS
Screening for Chlamydiales resulted in a total prevalence of 31.4%. Positive samples originated from captive and free-living bats from all three countries. Sequencing of 15 samples allowed the detection of two phylogenetically distinct groups. These groups share sequence identities to Chlamydiaceae, and to Chlamydia-like organisms including Rhabdochlamydiaceae and unclassified Chlamydiales from environmental samples, respectively. PCR analysis for the presence of hemotropic mycoplasmas resulted in a total prevalence of 0.7%, comprising free-living bats from Germany and Costa Rica. Phylogenetic analysis revealed three sequences related to other unidentified mycoplasmas found in vampire bats and Chilean bats.
CONCLUSIONS
Bats can harbor Chlamydiales and hemotropic mycoplasmas and the newly described sequences in this study indicate that the diversity of these bacteria in bats is much larger than previously thought. Both, Chlamydiales and hemotropic mycoplasmas are not restricted to certain bat species or countries and captive and free-living bats can be colonized. In conclusion, bats represent another potential host or vector for novel, previously unidentified, Chlamydiales and hemotropic mycoplasmas.
Topics: Animals; Chile; Chiroptera; Chlamydiaceae; Costa Rica; DNA, Bacterial; DNA, Ribosomal; Germany; Mycoplasma; Phylogeny; Phylogeography; Prevalence; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 32590949
DOI: 10.1186/s12866-020-01872-x -
Microbiology Spectrum Feb 2022Lung transplant recipients (LTRs) are vulnerable to hyperammonemia syndrome (HS) in the early postoperative period, a condition typically unresponsive to nonantibiotic...
Lung transplant recipients (LTRs) are vulnerable to hyperammonemia syndrome (HS) in the early postoperative period, a condition typically unresponsive to nonantibiotic interventions. HS in LTRs is strongly correlated with Ureaplasma infection of the respiratory tract, although it is not well understood what makes LTRs preferentially susceptible to HS compared to other immunocompromised hosts. Ureaplasma species harbor highly active ureases, and postoperative LTRs commonly experience uremia. We hypothesized that uremia could be a potentiating comorbidity, providing increased substrate for ureaplasmal ureases. Using a novel dialyzed flow system, the ammonia-producing capacities of four isolates of Ureaplasma parvum and six isolates of Ureaplasma urealyticum in media formulations relating to normal and uremic host conditions were tested. For all isolates, growth under simulated uremic conditions resulted in increased ammonia production over 24 h, despite similar endpoint bacterial quantities. Further, transcripts of (from the ureaplasmal urease gene cluster) from U. urealyticum IDRL-10763 and ATCC-27816 rose at similar rates under uremic and nonuremic conditions, with similar endpoint populations under the two conditions (despite markedly increased ammonia concentrations under uremic conditions), indicating that the difference in ammonia production by these isolates is due to increased urease activity, not expression. Lastly, uremic mice infected with an Escherichia coli strain harboring a U. urealyticum serovar 8 gene cluster exhibited higher blood ammonia levels compared to nonuremic mice infected with the same strain. Taken together, these data show that U. urealyticum and U. parvum produce more ammonia under uremic conditions compared to nonuremic conditions. This implies that uremia is a plausible contributing factor to Ureaplasma-induced HS in LTRs. Ureaplasma-induced hyperammonemia syndrome is a deadly complication affecting around 4% of lung transplant recipients and, to a lesser extent, other solid organ transplant patients. Understanding the underlying mechanisms will inform patient management, potentially decreasing mortality and morbidity. Here, it is shown that uremia is a plausible contributing factor to the pathophysiology of the condition.
Topics: Ammonia; Animals; Humans; Hyperammonemia; Immunocompromised Host; Lung; Lung Transplantation; Mice; Transplant Recipients; Ureaplasma; Ureaplasma urealyticum; Uremia; Urinary Tract
PubMed: 35171026
DOI: 10.1128/spectrum.01942-21 -
Nihon Saikingaku Zasshi. Japanese... 2015Bacteria have various way to move over solid surfaces, such as glass, agar, and host cell. These movements involve surface appendages including flagella, type IV pili... (Review)
Review
Bacteria have various way to move over solid surfaces, such as glass, agar, and host cell. These movements involve surface appendages including flagella, type IV pili and other "mysterious" nano-machineries. Gliding motility was a term used various surface movements by several mechanisms that have not been well understood in past few decades. However, development of visualization techniques allowed us to make much progress on their dynamics of machineries. It also provided us better understanding how bacteria move over surfaces and why bacteria move in natural environments. In this review, I will introduce recent studies on the gliding motility of Flavobacteium and Mycoplasma based on the detail observation of single cell and its motility machinery with micro-nano scales.
Topics: Bacterial Translocation; Fimbriae, Bacterial; Flagella; Flavobacterium; Mycoplasma
PubMed: 26632217
DOI: 10.3412/jsb.70.375 -
Deutsches Arzteblatt International Jul 2016
Topics: Humans; Ureaplasma urealyticum
PubMed: 27412992
DOI: 10.3238/arztebl.2016.0460b -
Frontiers in Immunology 2023can cause respiratory diseases, arthritis, genitourinary tract infections, and chronic fatigue syndrome and have been linked to the development of the human... (Review)
Review
can cause respiratory diseases, arthritis, genitourinary tract infections, and chronic fatigue syndrome and have been linked to the development of the human immunodeficiency virus. Because mycoplasma lacks a cell wall, its outer membrane lipoproteins are one of the main factors that induce inflammation in the organism and contribute to disease development. Macrophage-activating lipopeptide-2 (MALP-2) modulates the inflammatory response of monocytes/macrophages in a bidirectional fashion, indirectly enhances the cytotoxicity of NK cells, promotes oxidative bursts in neutrophils, upregulates surface markers on lymphocytes, enhances antigen presentation on dendritic cells and induces immune inflammatory responses in sebocytes and mesenchymal cells. MALP-2 is a promising vaccine adjuvant for this application. It also promotes vascular healing and regeneration, accelerates wound and bone healing, suppresses tumors and metastasis, and reduces lung infections and inflammation. MALP-2 has a simple structure, is easy to synthesize, and has promising prospects for clinical application. Therefore, this paper reviews the mechanisms of MALP-2 activation in immune cells, focusing on the application of MALP-2 in animals/humans to provide a basis for the study of pathogenesis in and the translation of MALP-2 into clinical applications.
Topics: Animals; Humans; Lipopeptides; Oligopeptides; Macrophages; Mycoplasma; Mycoplasma fermentans; Inflammation
PubMed: 36761746
DOI: 10.3389/fimmu.2023.1113715 -
International Journal of Molecular... Feb 2024is one of the smallest self-replicating organisms. It causes chronic respiratory disease, leading to significant economic losses in poultry industry. Following... (Review)
Review
is one of the smallest self-replicating organisms. It causes chronic respiratory disease, leading to significant economic losses in poultry industry. Following invasion, the pathogen can persist in the host owing to its immune evasion, resulting in long-term chronic infection. The strategies of immune evasion by mycoplasmas are very complex and recent research has unraveled these sophisticated mechanisms. The antigens of exhibit high-frequency changes in size and expression cycle, allowing them to evade the activation of the host humoral immune response. can invade non-phagocytic chicken cells and also regulate microRNAs to modulate cell proliferation, inflammation, and apoptosis in tracheal epithelial cells during the disease process. has been shown to transiently activate the inflammatory response and then inhibit it by suppressing key inflammatory mediators, avoiding being cleared. The regulation and activation of immune cells are important for host response against mycoplasma infection. However, has been shown to interfere with the functions of macrophages and lymphocytes, compromising their defense capabilities. In addition, the pathogen can cause immunological damage to organs by inducing an inflammatory response, cell apoptosis, and oxidative stress, leading to immunosuppression in the host. This review comprehensively summarizes these evasion tactics employed by , providing valuable insights into better prevention and control of mycoplasma infection.
Topics: Animals; Mycoplasma gallisepticum; Immune Evasion; Mycoplasma Infections; Chickens; Poultry; Poultry Diseases
PubMed: 38474071
DOI: 10.3390/ijms25052824