1
|
Liu W, Yang T, Kong Y, Xie X, Ruan Z. Ureaplasma infections: update on epidemiology, antimicrobial resistance, and pathogenesis. Crit Rev Microbiol 2024:1-31. [PMID: 38794781 DOI: 10.1080/1040841x.2024.2349556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 04/24/2024] [Indexed: 05/26/2024]
Abstract
Human Ureaplasma species are being increasingly recognized as opportunistic pathogens in human genitourinary tract infections, infertility, adverse pregnancy, neonatal morbidities, and other adult invasive infections. Although some general reviews have focused on the detection and clinical manifestations of Ureaplasma spp., the molecular epidemiology, antimicrobial resistance, and pathogenesis of Ureaplasma spp. have not been adequately explained. The purpose of this review is to offer valuable insights into the current understanding and future research perspectives of the molecular epidemiology, antimicrobial resistance, and pathogenesis of human Ureaplasma infections. This review summarizes the conventional culture and detection methods and the latest molecular identification technologies for Ureaplasma spp. We also reviewed the global prevalence and mechanisms of antibiotic resistance for Ureaplasma spp. Aside from regular antibiotics, novel antibiotics with outstanding in vitro antimicrobial activity against Ureaplasma spp. are described. Furthermore, we discussed the pathogenic mechanisms of Ureaplasma spp., including adhesion, proinflammatory effects, cytotoxicity, and immune escape effects, from the perspectives of pathology, related molecules, and genetics.
Collapse
Affiliation(s)
- Wenwen Liu
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, China
| | - Ting Yang
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, China
| | - Yingying Kong
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, China
| | - Xinyou Xie
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, China
| | - Zhi Ruan
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Precision Medicine in Diagnosis and Monitoring Research of Zhejiang Province, Hangzhou, China
| |
Collapse
|
2
|
Tian M, Zhang W, Zhang G, Bahadur A, Wu S, Yu X, Wu Y, Jia P, Chen T, Liu G. A novel UV-resistant bacterium Sphingomonas endolithica sp. nov., and genomic analysis, isolated from the north slope of Mount Everest. Antonie Van Leeuwenhoek 2023; 117:5. [PMID: 38153511 DOI: 10.1007/s10482-023-01903-3] [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: 07/17/2023] [Accepted: 11/28/2023] [Indexed: 12/29/2023]
Abstract
Gram-stain-negative, aerobic, rod-shaped, non-motile bacterium strain ZFBP2030T was isolated from a rock on the North slope of Mount Everest. This strain contained a unique ubiquinone-10 (Q-10) as a predominant respiratory quinone. Among the tested fatty acids, the strain contained summed feature 8, C14:0 2OH, and C16:0, as major cellular fatty acids. The polar lipid profile contained phosphatidyl glycerol, phosphatidyl ethanolamine, three unidentified phospholipids, two unidentified aminolipids, and six unidentified lipids. The cell-wall peptidoglycan was a meso-diaminopimelic acid, and cell-wall sugars were ribose and galactose. Phylogenetic analyses based on 16S rRNA gene sequence revealed that strain ZFBP2030T was a member of the genus Sphingomonas, exhibiting high sequence similarity to the 16S rRNA gene sequences of Sphingomonas aliaeris DH-S5T (97.9%), Sphingomonas alpina DSM 22537T (97.3%) and Sphingomonas hylomeconis CCTCC AB 2013304T (97.0%). The 16S rRNA gene sequence similarity between ZFBP2030T and other typical strains was less than 97.0%. The average amino acid identity values, average nucleotide identity, and digital DNA-DNA hybridization values between strain ZFBP2030T and its highest sequence similarity strains were 56.9-79.9%, 65.1-82.2%, and 19.3-25.8%, respectively. The whole-genome size of the novel strain ZFBP2030T was 4.1 Mbp, annotated with 3838 protein-coding genes and 54 RNA genes. Moreover, DNA G + C content was 64.7 mol%. Stress-related functions predicted in the subsystem classification of the strain ZFBP2030T genome included osmotic, oxidative, cold/heat shock, detoxification, and periplasmic stress responses. The overall results of this study clearly showed that strain ZFBP2030T is a novel species of the genus Sphingomonas, for which the name Sphingomonas endolithica sp. nov. is proposed. The type of strain is ZFBP2030T (= EE 013T = GDMCC 1.3123T = JCM 35386T).
Collapse
Affiliation(s)
- Mao Tian
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu Province, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou, 730000, Gansu Province, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wei Zhang
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou, 730000, Gansu Province, China.
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, 320 Donggang West Road, Lanzhou, 730000, Gansu Province, China.
| | - Gaosen Zhang
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou, 730000, Gansu Province, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, 320 Donggang West Road, Lanzhou, 730000, Gansu Province, China
| | - Ali Bahadur
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu Province, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou, 730000, Gansu Province, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shiyu Wu
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu Province, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou, 730000, Gansu Province, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xue Yu
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou, 730000, Gansu Province, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, 320 Donggang West Road, Lanzhou, 730000, Gansu Province, China
| | - Yujie Wu
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu Province, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou, 730000, Gansu Province, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Puchao Jia
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou, 730000, Gansu Province, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, 320 Donggang West Road, Lanzhou, 730000, Gansu Province, China
| | - Tuo Chen
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu Province, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou, 730000, Gansu Province, China
| | - Guangxiu Liu
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, Gansu Province, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou, 730000, Gansu Province, China
| |
Collapse
|
3
|
Qin L, Liu L, Wu Y, Chen Y, Wu Y, Luo H, Xi Y, Xiu F, Hu J, Chen L, Wu N, He J, Zeng Y, Zhu C, You X. Mycoplasma pneumoniae downregulates RECK to promote matrix metalloproteinase-9 secretion by bronchial epithelial cells. Virulence 2022; 13:1270-1284. [PMID: 35892136 PMCID: PMC9336473 DOI: 10.1080/21505594.2022.2101746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Airway epithelial cells function as both a physical barrier against harmful substances and pathogenic microorganisms and as an important participant in the innate immune system. Matrix metalloproteinase-9 (MMP-9) plays a crucial role in modulating inflammatory responses during respiratory infections. However, the signalling cascade that induces MMP-9 secretion from epithelial cells infected with Mycoplasma pneumoniae remains poorly understood. In this study, we investigated the mechanism of MMP-9 secretion in airway epithelial cells infected with M. pneumoniae. Our data clearly showed that M. pneumoniae induced the secretion of MMP-9 from bronchial epithelial cells and upregulated its enzymatic activity in a time- and dose-dependent manner. Using specific inhibitors and chromatin co-precipitation experiments, we confirmed that the expression of MMP-9 is reliant on the activation of the Toll-like receptor 2 (TLR2) and TLR6-dependent mitogen-activated protein kinase/nuclear factor- κB/activator protein-1 (MAPK/NF-κB/AP-1) pathways. Additionally, epigenetic modifications such as histone acetylation and the nuclear transcription factor Sp1 also regulate MMP-9 expression. M. pneumoniae infection also decreased the expression of the tumour suppressor reversion-inducing cysteine-rich protein with Kazal motifs (RECK) by inducing Sp1 phosphorylation. Overexpression of RECK significantly impaired the M. pneumoniae-triggered increase in MMP-9 enzymatic activity, although the level of MMP-9 protein remained constant. The study demonstrated that M. pneumoniae-triggered MMP-9 expression is modulated by TLR2 and 6, the MAPK/NF-κB/AP-1 signalling cascade, and histone acetylation, and M. pneumoniae downregulated the expression of RECK, thereby increasing MMP-9 activity to modulate the inflammatory response, which could play a role in airway remodelling.
Collapse
Affiliation(s)
- Lianmei Qin
- 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.,Department of Blood Transfusion, Shenzhen Children's Hospital, Shenzhen, China
| | - Lu Liu
- 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
| | - Yueping Wu
- Department of Blood Transfusion, Shenzhen Children's Hospital, Shenzhen, China
| | - Yiwen Chen
- 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
| | - Yueyue Wu
- 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
- Department of Clinical Laboratory, The Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Yixuan Xi
- 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
| | - Feichen Xiu
- 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
| | - Jun Hu
- Department of Cardiothoracic Surgery, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Liesong Chen
- 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
| | - Ning Wu
- Department of Clinical Laboratory, Hengyang No.1 People's Hospital, Hengyang, China
| | - Jun He
- Department of Clinical Laboratory, The Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Yanhua Zeng
- 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
| | - Cuiming Zhu
- 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
| | - 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
| |
Collapse
|
4
|
DnaJ, a promising vaccine candidate against Ureaplasma urealyticum infection. Appl Microbiol Biotechnol 2022; 106:7643-7659. [PMID: 36269329 PMCID: PMC9589543 DOI: 10.1007/s00253-022-12230-4] [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: 05/17/2022] [Revised: 09/20/2022] [Accepted: 10/05/2022] [Indexed: 11/08/2022]
Abstract
Abstract
Ureaplasma urealyticum (U. urealyticum, Uu) is a common sexually transmitted pathogen that is responsible for diseases such as non-gonococcal urethritis, chorioamnionitis, and neonatal respiratory diseases. The rapid emergence of multidrug-resistant bacteria threatens the effective treatment of Uu infections. Considering this, vaccination could be an efficacious medical intervention to prevent Uu infection and disease. As a highly conserved molecular chaperone, DnaJ is expressed and upregulated by pathogens soon after infection. Here, we assessed the vaccine potential of recombinant Uu-DnaJ in a mouse model and dendritic cells. Results showed that intramuscular administration of DnaJ induced robust humoral- and T helper (Th) 1 cell-mediated immune responses and protected against genital tract infection, inflammation, and the pathologic sequelae after Uu infection. Importantly, the DnaJ protein also induced the maturation of mouse bone marrow–derived dendritic cells (BMDCs), ultimately promoting naïve T cell differentiation toward the Th1 phenotype. In addition, adoptive immunization of DnaJ-pulsed BMDCs elicited antigen-specific Immunoglobulin G2 (IgG2) antibodies as well as a Th1-biased cellular response in mice. These results support DnaJ as a promising vaccine candidate to control Uu infections. Key points • A novel recombinant vaccine was constructed against U. urealyticum infection. • Antigen-specific humoral and cellular immune responses after DnaJ vaccination. • Dendritic cells are activated by Uu-DnaJ, which results in a Th1-biased immune response. Supplementary Information The online version contains supplementary material available at 10.1007/s00253-022-12230-4.
Collapse
|
5
|
Wanna W, Surachat K, Kaitimonchai P, Phongdara A. Evaluation of probiotic characteristics and whole genome analysis of Pediococcus pentosaceus MR001 for use as probiotic bacteria in shrimp aquaculture. Sci Rep 2021; 11:18334. [PMID: 34526534 PMCID: PMC8443617 DOI: 10.1038/s41598-021-96780-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 08/12/2021] [Indexed: 02/08/2023] Open
Abstract
The development of non-antibiotic and environmentally friendly agents is a key consideration for health management in shrimp aquaculture. In this study, the probiotic potential in shrimp aquaculture of Pediococcus pentosaceus MR001, isolated from Macrobrachium rosenbergii, was investigated by means of feeding trial and genetic characterization. In the feeding trial, dietary supplementation with P. pentosaceus MR001 significantly increased weight gain and digestive enzyme activity (p < 0.05) in shrimp, Litopenaeus vannamei. The intestinal histology showed that shrimp given the probiotic diet had healthier guts than the control group. Also, the immune gene expression and the survival rate in the treatment group were significantly increased when compared with the control group. The genetic characteristics of P. pentosaceus strain MR001 were explored by performing whole-genome sequencing (WGS) using the HiSeq 2500 platform and PacBio system, revealing the complete circular genome of 1,804,896 bp. We also identified 1789 coding genes and subsequently characterized genes related to the biosynthesis of bacteriocins, stress resistance, and bile tolerance. Our findings suggest that insights in the functional and genetic characteristics of P. pentosaceus strain MR001 could provide opportunities for applications of such strain in shrimp diet supplementation.
Collapse
Affiliation(s)
- Warapond Wanna
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand.
- Center for Genomics and Bioinformatics Research, Faculty of Science, Prince of Songkla University, Songkhla, 90110, Thailand.
| | - Komwit Surachat
- Division of Computational Science, Faculty of Science, Prince of Songkla University, Songkhla, 90110, Thailand
- Molecular Evolution and Computational Biology Research Unit, Faculty of Science, Prince of Songkla University, Hat Yai, 90110, Songkhla, Thailand
| | - Panmile Kaitimonchai
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Amornrat Phongdara
- Center for Genomics and Bioinformatics Research, Faculty of Science, Prince of Songkla University, Songkhla, 90110, Thailand
- Faculty of Medical Technology, Prince of Songkla University, Songkhla, 90110, Thailand
| |
Collapse
|
6
|
Qin L, Chen Y, You X. Subversion of the Immune Response by Human Pathogenic Mycoplasmas. Front Microbiol 2019; 10:1934. [PMID: 31497004 PMCID: PMC6712165 DOI: 10.3389/fmicb.2019.01934] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 08/06/2019] [Indexed: 12/17/2022] Open
Abstract
Mycoplasmas are a large group of prokaryotes which is believed to be originated from Gram-positive bacteria via degenerative evolution, and mainly capable of causing a wide range of human and animal infections. Although innate immunity and adaptive immunity play crucial roles in preventing mycoplasma infection, immune response that develops after infection fails to completely eliminate this bacterium under certain circumstances. Thus, it is reasonable to speculate that mycoplasmas employ some mechanisms to deal with coercion of host defense system. In this review, we will highlight and provide a comprehensive overview of immune evasion strategies that have emerged in mycoplasma infection, which can be divided into four aspects: (i) Molecular mimicry and antigenic variation on the surface of the bacteria to evade the immune surveillance; (ii) Overcoming the immune effector molecules assaults: Induction of detoxified enzymes to degradation of reactive oxygen species; Expression of nucleases to degrade the neutrophil extracellular traps to avoid killing by Neutrophil; Capture and cleavage of immunoglobulins to evade humoral immune response; (iii) Persistent survival: Invading into the host cell to escape the immune damage; Formation of a biofilm to establish a persistent infection; (iv) Modulation of the immune system to down-regulate the intensity of immune response. All of these features increase the probability of mycoplasma survival in the host and lead to a persistent, chronic infections. A profound understanding on the mycoplasma to subvert the immune system will help us to better understand why mycoplasma is so difficult to eradicate and ultimately provide new insights on the development of therapeutic regimens against this bacterium in future.
Collapse
Affiliation(s)
- Lianmei Qin
- Institute of Pathogenic Biology, Hengyang Medical College, 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
| | - Yiwen Chen
- Institute of Pathogenic Biology, Hengyang Medical College, 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
| | - Xiaoxing You
- Institute of Pathogenic Biology, Hengyang Medical College, 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
| |
Collapse
|
7
|
Expanding the Diversity of Myoviridae Phages Infecting Lactobacillus plantarum-A Novel Lineage of Lactobacillus Phages Comprising Five New Members. Viruses 2019; 11:v11070611. [PMID: 31277436 PMCID: PMC6669764 DOI: 10.3390/v11070611] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/07/2019] [Accepted: 07/02/2019] [Indexed: 01/01/2023] Open
Abstract
Lactobacillus plantarum is a bacterium with probiotic properties and promising applications in the food industry and agriculture. So far, bacteriophages of this bacterium have been moderately addressed. We examined the diversity of five new L. plantarum phages via whole genome shotgun sequencing and in silico protein predictions. Moreover, we looked into their phylogeny and their potential genomic similarities to other complete phage genome records through extensive nucleotide and protein comparisons. These analyses revealed a high degree of similarity among the five phages, which extended to the vast majority of predicted virion-associated proteins. Based on these, we selected one of the phages as a representative and performed transmission electron microscopy and structural protein sequencing tests. Overall, the results suggested that the five phages belong to the family Myoviridae, they have a long genome of 137,973-141,344 bp, a G/C content of 36.3-36.6% that is quite distinct from their host's, and surprisingly, 7 to 15 tRNAs. Only an average 41/174 of their predicted genes were assigned a function. The comparative analyses unraveled considerable genetic diversity for the five L. plantarum phages in this study. Hence, the new genus "Semelevirus" was proposed, comprising exclusively of the five phages. This novel lineage of Lactobacillus phages provides further insight into the genetic heterogeneity of phages infecting Lactobacillus sp. The five new Lactobacillus phages have potential value for the development of more robust starters through, for example, the selection of mutants insensitive to phage infections. The five phages could also form part of phage cocktails, which producers would apply in different stages of L. plantarum fermentations in order to create a range of organoleptic outputs.
Collapse
|
8
|
Chen LS, Li C, You XX, Lin YW, Wu YM. The mpn668 gene of Mycoplasma pneumoniae encodes a novel organic hydroperoxide resistance protein. Int J Med Microbiol 2018; 308:776-783. [DOI: 10.1016/j.ijmm.2018.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 03/18/2018] [Accepted: 04/26/2018] [Indexed: 02/03/2023] Open
|
9
|
Eid R, Arab NTT, Greenwood MT. Iron mediated toxicity and programmed cell death: A review and a re-examination of existing paradigms. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:399-430. [PMID: 27939167 DOI: 10.1016/j.bbamcr.2016.12.002] [Citation(s) in RCA: 165] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 11/08/2016] [Accepted: 12/04/2016] [Indexed: 12/11/2022]
Abstract
Iron is an essential micronutrient that is problematic for biological systems since it is toxic as it generates free radicals by interconverting between ferrous (Fe2+) and ferric (Fe3+) forms. Additionally, even though iron is abundant, it is largely insoluble so cells must treat biologically available iron as a valuable commodity. Thus elaborate mechanisms have evolved to absorb, re-cycle and store iron while minimizing toxicity. Focusing on rarely encountered situations, most of the existing literature suggests that iron toxicity is common. A more nuanced examination clearly demonstrates that existing regulatory processes are more than adequate to limit the toxicity of iron even in response to iron overload. Only under pathological or artificially harsh situations of exposure to excess iron does it become problematic. Here we review iron metabolism and its toxicity as well as the literature demonstrating that intracellular iron is not toxic but a stress responsive programmed cell death-inducing second messenger.
Collapse
Affiliation(s)
- Rawan Eid
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, Canada
| | - Nagla T T Arab
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, Canada
| | - Michael T Greenwood
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, Canada.
| |
Collapse
|