1
|
Schwab NR, Young NE, Nzenwata DU, Toh E, Mikulin JA, Wilson TJ, Nelson DE, Balish MF. Characterization of Virulence-Associated Traits in Mycoplasma penetrans Strains Acting as Likely Etiological Agents of Idiopathic Nongonococcal Urethritis. J Infect Dis 2023; 227:1050-1058. [PMID: 36588346 PMCID: PMC10319971 DOI: 10.1093/infdis/jiac505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 12/22/2022] [Accepted: 12/30/2022] [Indexed: 01/03/2023] Open
Abstract
Mycoplasma penetrans is an emerging pathogen with a reduced genome. This bacterium has only previously been cultured from individuals with chronic immunodeficiencies. Here we report the characteristics of 4 M. penetrans isolates from the urine of immunocompetent males with nongonococcal urethritis, in comparison with strain HF-2 from an immunocompromised patient. Several features exhibited distinct differences between these isolates and HF-2. Unlike HF-2, all 4 were resistant to azithromycin. They exhibited greater sialic acid-dependent binding to erythrocytes, gliding motility speed, and H2O2 production than HF-2. All new isolates produced thinner capsules than HF-2. Invasiveness varied, with some isolates being more invasive than HF-2 and some less invasive. Cytotoxicity to HeLa cells was similar to HF-2, and all strains could clear extracellular traps produced by innate immune cells. We conclude that subtle differences among M. penetrans strains may be critical for this organism to establish an infection in an otherwise healthy individual.
Collapse
Affiliation(s)
- Nathan R Schwab
- Department of Microbiology, Miami University, Oxford, Ohio, USA
| | - Natalie E Young
- Department of Microbiology, Miami University, Oxford, Ohio, USA
| | | | - Evelyn Toh
- Department of Microbiology and Immunology, School of Medicine, Indiana University, Indianapolis, Indiana, USA
| | | | | | - David E Nelson
- Department of Microbiology and Immunology, School of Medicine, Indiana University, Indianapolis, Indiana, USA
| | | |
Collapse
|
2
|
Su X, You X, Luo H, Liang K, Chen L, Tian W, Ye Z, He J. Community-Acquired Respiratory Distress Syndrome Toxin: Unique Exotoxin for M. pneumoniae. Front Microbiol 2021; 12:766591. [PMID: 34867898 PMCID: PMC8640204 DOI: 10.3389/fmicb.2021.766591] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/19/2021] [Indexed: 11/13/2022] Open
Abstract
Mycoplasma pneumoniae infection often causes respiratory diseases in humans, particularly in children and adults with atypical pneumonia and community-acquired pneumonia (CAP), and is often exacerbated by co-infection with other lung diseases, such as asthma, bronchitis, and chronic obstructive pulmonary disorder. Community-acquired respiratory distress syndrome toxin (CARDS TX) is the only exotoxin produced by M. pneumoniae and has been extensively studied for its ADP-ribosyltransferase (ADPRT) activity and cellular vacuolization properties. Additionally, CARDS TX induces inflammatory responses, resulting in cell swelling, nuclear lysis, mucus proliferation, and cell vacuolization. CARDS TX enters host cells by binding to the host receptor and is then reverse transported to the endoplasmic reticulum to exert its pathogenic effects. In this review, we focus on the structural characteristics, functional activity, distribution and receptors, mechanism of cell entry, and inflammatory response of CARDS TX was examined. Overall, the findings of this review provide a theoretical basis for further investigation of the mechanism of M. pneumoniae infection and the development of clinical diagnosis and vaccines.
Collapse
Affiliation(s)
- Xiaoling Su
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, China
| | - Xiaoxing You
- Institute of Pathogenic Biology, Hengyang Medical School, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Haodang Luo
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, China
| | - Keying Liang
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, China
| | - Li Chen
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, China
| | - Wei Tian
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, China
| | - Zufeng Ye
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, China
| | - Jun He
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, China
| |
Collapse
|
3
|
Metal utilization in genome-reduced bacteria: Do human mycoplasmas rely on iron? Comput Struct Biotechnol J 2021; 19:5752-5761. [PMID: 34765092 PMCID: PMC8566771 DOI: 10.1016/j.csbj.2021.10.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/08/2021] [Accepted: 10/12/2021] [Indexed: 12/04/2022] Open
Abstract
Mycoplasmas are parasitic bacteria with streamlined genomes and complex nutritional requirements. Although iron is vital for almost all organisms, its utilization by mycoplasmas is controversial. Despite its minimalist nature, mycoplasmas can survive and persist within the host, where iron availability is rigorously restricted through nutritional immunity. In this review, we describe the putative iron-enzymes, transporters, and metalloregulators of four relevant human mycoplasmas. This work brings in light critical differences in the mycoplasma-iron interplay. Mycoplasma penetrans, the species with the largest genome (1.36 Mb), shows a more classic repertoire of iron-related proteins, including different enzymes using iron-sulfur clusters as well as iron storage and transport systems. In contrast, the iron requirement is less apparent in the three species with markedly reduced genomes, Mycoplasma genitalium (0.58 Mb), Mycoplasma hominis (0.67 Mb) and Mycoplasma pneumoniae (0.82 Mb), as they exhibit only a few proteins possibly involved in iron homeostasis. The multiple facets of iron metabolism in mycoplasmas illustrate the remarkable evolutive potential of these minimal organisms when facing nutritional immunity and question the dependence of several human-infecting species for iron. Collectively, our data contribute to better understand the unique biology and infective strategies of these successful pathogens.
Collapse
Key Words
- ABC, ATP-binding cassette
- ECF transporter
- ECF, energy-coupling factor
- Fur, ferric uptake regulator
- Hrl, histidine-rich lipoprotein
- Iron homeostasis
- Metal acquisition
- Metalloenzyme
- Mge, Mycoplasma genitalium
- Mho, Mycoplasma hominis
- Mollicutes
- Mpe, Mycoplasma penetrans
- Mpn, Mycoplasma pneumonia
- Mycoplasmas
- PDB, protein data bank
- RNR, ribonucleotide reductase
- XRF, X-ray fluorescence
- ZIP, zinc-iron permease
Collapse
|
4
|
Ramasamy K, Balasubramanian S, Kirkpatrick A, Szabo D, Pandranki L, Baseman JB, Kannan TR. Mycoplasma pneumoniae CARDS toxin exploits host cell endosomal acidic pH and vacuolar ATPase proton pump to execute its biological activities. Sci Rep 2021; 11:11571. [PMID: 34078958 PMCID: PMC8172646 DOI: 10.1038/s41598-021-90948-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 05/19/2021] [Indexed: 11/09/2022] Open
Abstract
Mycoplasma pneumoniae is the leading cause of bacterial community-acquired pneumonia among hospitalized children in the United States. It is also responsible for a spectrum of other respiratory tract disorders and extrapulmonary manifestations in children and adults. The main virulence factor of M. pneumoniae is a 591 amino acid multifunctional protein called Community Acquired Respiratory Distress Syndrome (CARDS) toxin. The amino terminal region of CARDS toxin (N-CARDS) retains ADP-ribosylating activity and the carboxy region (C-CARDS) contains the receptor binding and vacuolating activities. After internalization, CARDS toxin is transported in a retrograde manner from endosome through the Golgi complex into the endoplasmic reticulum. However, the mechanisms and criteria by which internalized CARDS toxin is transported and activated to execute its cytotoxic effects remain unknown. In this study, we used full-length CARDS toxin and its mutant and truncated derivatives to analyze how pharmacological drugs that alter pH of intracellular vesicles and electrical potential across vesicular membranes affect translocation of CARDS toxin in mammalian cells. Our results indicate that an acidic environment is essential for CARDS toxin retrograde transport to endoplasmic reticulum. Moreover, retrograde transport facilitates toxin clipping and is required to induce vacuole formation. Additionally, toxin-mediated cell vacuolation is strictly dependent on the function of vacuolar type-ATPase.
Collapse
Affiliation(s)
- Kumaraguruparan Ramasamy
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Sowmya Balasubramanian
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Alejandra Kirkpatrick
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Daniel Szabo
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Lavanya Pandranki
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Joel B Baseman
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - T R Kannan
- Department of Microbiology, Immunology and Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX, 78229, USA.
| |
Collapse
|
5
|
Yiwen C, Yueyue W, Lianmei Q, Cuiming Z, Xiaoxing Y. Infection strategies of mycoplasmas: Unraveling the panoply of virulence factors. Virulence 2021; 12:788-817. [PMID: 33704021 PMCID: PMC7954426 DOI: 10.1080/21505594.2021.1889813] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Mycoplasmas, the smallest bacteria lacking a cell wall, can cause various diseases in both humans and animals. Mycoplasmas harbor a variety of virulence factors that enable them to overcome numerous barriers of entry into the host; using accessory proteins, mycoplasma adhesins can bind to the receptors or extracellular matrix of the host cell. Although the host immune system can eradicate the invading mycoplasma in most cases, a few sagacious mycoplasmas employ a series of invasion and immune escape strategies to ensure their continued survival within their hosts. For instance, capsular polysaccharides are crucial for anti-phagocytosis and immunomodulation. Invasive enzymes degrade reactive oxygen species, neutrophil extracellular traps, and immunoglobulins. Biofilm formation is important for establishing a persistent infection. During proliferation, successfully surviving mycoplasmas generate numerous metabolites, including hydrogen peroxide, ammonia and hydrogen sulfide; or secrete various exotoxins, such as community-acquired respiratory distress syndrome toxin, and hemolysins; and express various pathogenic enzymes, all of which have potent toxic effects on host cells. Furthermore, some inherent components of mycoplasmas, such as lipids, membrane lipoproteins, and even mycoplasma-generated superantigens, can exert a significant pathogenic impact on the host cells or the immune system. In this review, we describe the proposed virulence factors in the toolkit of notorious mycoplasmas to better understand the pathogenic features of these bacteria, along with their pathogenic mechanisms.
Collapse
Affiliation(s)
- Chen Yiwen
- Institute of Pathogenic Biology, Hengyang Medical College, University of South China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, China
| | - Wu Yueyue
- Institute of Pathogenic Biology, Hengyang Medical College, University of South China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, China
| | - Qin Lianmei
- Institute of Pathogenic Biology, Hengyang Medical College, University of South China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, China
| | - Zhu Cuiming
- Institute of Pathogenic Biology, Hengyang Medical College, University of South China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, China
| | - You Xiaoxing
- Institute of Pathogenic Biology, Hengyang Medical College, University of South China; Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control; Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, China
| |
Collapse
|
6
|
Pritchard RE, Balish MF. Mycoplasma iowae: relationships among oxygen, virulence, and protection from oxidative stress. Vet Res 2015; 46:36. [PMID: 25880161 PMCID: PMC4367981 DOI: 10.1186/s13567-015-0170-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/05/2015] [Indexed: 12/20/2022] Open
Abstract
The poultry-associated bacterium Mycoplasma iowae colonizes multiple sites in embryos, with disease or death resulting. Although M. iowae accumulates in the intestinal tract, it does not cause disease at that site, but rather only in tissues that are exposed to atmospheric O2. The activity of M. iowae catalase, encoded by katE, is capable of rapid removal of damaging H2O2 from solution, and katE confers a substantial reduction in the amount of H2O2 produced by Mycoplasma gallisepticum katE transformants in the presence of glycerol. As catalase-producing bacteria are often beneficial to hosts with inflammatory bowel disease, we explored whether M. iowae was exclusively protective against H2O2-producing bacteria in a Caenorhabditis elegans model, whether its protectiveness changed in response to O2 levels, and whether expression of genes involved in H2O2 metabolism and virulence changed in response to O2 levels. We observed that M. iowae was in fact protective against H2O2-producing Streptococcus pneumoniae, but not HCN-producing Pseudomonas aeruginosa, and that M. iowae cells grown in 1% O2 promoted survival of C. elegans to a greater extent than M. iowae cells grown in atmospheric O2. Transcript levels of an M. iowae gene encoding a homolog of Mycoplasma pneumoniae CARDS toxin were 5-fold lower in cells grown in low O2. These data suggest that reduced O2, representing the intestinal environment, triggers M. iowae to reduce its virulence capabilities, effecting a change from a pathogenic mode to a potentially beneficial one.
Collapse
Affiliation(s)
- Rachel E Pritchard
- Department of Microbiology, Miami University, Oxford, OH, 45056, USA. .,Present address: Division of Natural Sciences and Mathematics, Kentucky Wesleyan College, Owensboro, KY, 42301, USA.
| | - Mitchell F Balish
- Department of Microbiology, Miami University, Oxford, OH, 45056, USA.
| |
Collapse
|
7
|
Fieldhouse RJ, Turgeon Z, White D, Merrill AR. Cholera- and anthrax-like toxins are among several new ADP-ribosyltransferases. PLoS Comput Biol 2010; 6:e1001029. [PMID: 21170356 PMCID: PMC3000352 DOI: 10.1371/journal.pcbi.1001029] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Accepted: 11/10/2010] [Indexed: 11/19/2022] Open
Abstract
Chelt, a cholera-like toxin from Vibrio cholerae, and Certhrax, an anthrax-like toxin from Bacillus cereus, are among six new bacterial protein toxins we identified and characterized using in silico and cell-based techniques. We also uncovered medically relevant toxins from Mycobacterium avium and Enterococcus faecalis. We found agriculturally relevant toxins in Photorhabdus luminescens and Vibrio splendidus. These toxins belong to the ADP-ribosyltransferase family that has conserved structure despite low sequence identity. Therefore, our search for new toxins combined fold recognition with rules for filtering sequences--including a primary sequence pattern--to reduce reliance on sequence identity and identify toxins using structure. We used computers to build models and analyzed each new toxin to understand features including: structure, secretion, cell entry, activation, NAD+ substrate binding, intracellular target binding and the reaction mechanism. We confirmed activity using a yeast growth test. In this era where an expanding protein structure library complements abundant protein sequence data--and we need high-throughput validation--our approach provides insight into the newest toxin ADP-ribosyltransferases.
Collapse
Affiliation(s)
- Robert J. Fieldhouse
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Zachari Turgeon
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Dawn White
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - A. Rod Merrill
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| |
Collapse
|
8
|
Identification of lipoprotein MslA as a neoteric virulence factor of Mycoplasma gallisepticum. Infect Immun 2010; 78:3475-83. [PMID: 20515935 DOI: 10.1128/iai.00154-10] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Many lipoproteins are expressed on the surfaces of mycoplasmas, and some have been implicated as playing roles in pathogenesis. Family 2 lipoproteins of Mycoplasma pneumoniae have a conserved "mycoplasma lipoprotein X" central domain and a "mycoplasma lipoprotein 10" C-terminal domain and are differentially expressed in response to environmental conditions. Homologues of family 2 lipoproteins are Mycoplasma specific and include the lipoprotein of Mycoplasma gallisepticum, encoded by the MGA0674 gene. Comparative transcriptomic analysis of the M. gallisepticum live attenuated vaccine strain F and the virulent strain R(low), reported in this study, indicated that MGA0674 is one of several differentially expressed genes. The MGA0674-encoded lipoprotein is a proteolytically processed, immunogenic, TX-114 detergent-phase protein which appears to have antigenic divergence between field strains R(low) and S6. We examined the virulence of an R(low) Delta MGA0674 mutant (P1H9) in vivo and observed reduced recovery and attenuated virulence in the tracheas of experimentally infected chickens. The virulence of two additional R(low) Delta MGA0674 mutants, 2162 and 2204, was assessed in a second in vivo virulence experiment. These mutants exhibited partial to complete attenuation in vivo, but recovery was observed more frequently. Since only Mycoplasma species harbor homologues of MGA0674, the gene product has been renamed "Mycoplasma-specific lipoprotein A" (MslA). Collectively, these data indicate that MslA is an immunogenic lipoprotein exhibiting reduced expression in an attenuated strain and plays a role in M. gallisepticum virulence.
Collapse
|