1.Discovery, structure and function of plasmid mediated shufflon.
Tian YI ; Yang WANG ; Jianzhong SHEN ; Congming WU ; Yingbo SHEN
Chinese Journal of Biotechnology 2023;39(1):34-44
Antimicrobial resistance has become a major public health issue of global concern. Conjugation is an important way for fast spreading drug-resistant plasmids, during which the type Ⅳ pili plays an important role. Type Ⅳ pili can adhere on the surfaces of host cell and other medium, facilitating formation of bacterial biofilms, bacterial aggregations and microcolonies, and is also a critical factor in liquid conjugation. PilV is an adhesin-type protein found on the tip of type Ⅳ pili encoded by plasmid R64, and can recognize the lipopolysaccharid (LPS) molecules that locate on bacterial membrane. The shufflon is a clustered inversion region that diversifies the PilV protein, which consequently affects the recipient recognition and conjugation frequency in liquid mating. The shufflon was firstly discovered on an IncI1 plasmid R64 and has been identified subsequently in plasmids IncI2, IncK and IncZ, as well as the pathogenicity island of Salmonella typhi. The shufflon consists of four segments including A, B, C, and D, and a specific recombination site named sfx. The shufflon is regulated by its downstream-located recombinase-encoding gene rci, and different rearrangements of the shufflon region in different plasmids were observed. Mobile colistin resistance gene mcr-1, which has attracted substantial attentions recently, is mainly located in IncI2 plasmid. The shufflon may be one of the contributors to fast spread of mcr-1. Herein, we reviewed the discovery, structure, function and prevalence of plasmid mediated shufflon, aiming to provide a theoretical basis on transmission mechanism and control strategy of drug-resistant plasmids.
Plasmids/genetics*
;
Proteins/genetics*
;
Bacteria/genetics*
;
Recombinases
;
Genes, Bacterial
;
Anti-Bacterial Agents
2.Differential transcription of mating-type genes during sexual reproduction of natural Cordyceps sinensis.
Xiu-Zhang LI ; Yu-Ling LI ; Jia-Shi ZHU
China Journal of Chinese Materia Medica 2023;48(10):2829-2840
Natural Cordyceps sinensis as an insect-fungal complex, which is developed after Ophiocordyceps sinensis infects a larva of Hepialidae family. Seventeen genotypes of O. sinensis have been identified in natural C. sinensis. This paper summarized the literature reports and GenBank database regarding occurrence and transcription of the mating-type genes of MAT1-1 and MAT1-2 idiomorphs in natural C. sinensis, in Hirsutella sinensis(GC-biased Genotype #1 of O. sinensis), to infer the mating pattern of O. sinensis in the lifecycle of natural C. sinensis. The mating-type genes and transcripts of MAT1-1 and MAT1-2 idiomorphs were identified in the metagenomes and metatranscriptomes of natural C. sinensis. However, their fungal sources are unclear because of co-colonization of several genotypes of O. sinensis and multiple fungal species in natural C. sinensis. The mating-type genes of MAT1-1 and MAT1-2 idiomorphs were differentially present in 237 H. sinensis strains, constituting the genetic control of the O. sinensis reproduction. Transcriptional control of the O. sinensis reproduction includes: differential transcription or silencing of the mating-type genes of MAT1-1 and MAT1-2 idiomorphs, and the MAT1-2-1 transcript with unspliced intron I that contains 3 stop codons. Research on the H. sinensis transcriptome demonstrated differential and complementary transcriptions of the mating-type genes of MAT1-1 and MAT1-2 idiomorphs in Strains L0106 and 1229, which may become mating partners to accomplish physiological heterothallism. The differential occurrence and transcription of the mating-type genes in H. sinensis are inconsistent with the self-fertilization hypothesis under homothallism or pseudohomothallism, but instead indicate the need of mating partners of the same H. sinensis species, either monoecious or dioecious, for physiological heterothallism, or heterospecific species for hybridization. Multiple GC-and AT-biased genotypes of O. sinensis were identified in the stroma, stromal fertile portion(densely covered with numerous ascocarps) and ascospores of natural C. sinensis. It needs to be further explored if the genome-independent O. sinensis genotypes could become mating partners to accomplish sexual reproduction. S. hepiali Strain FENG experienced differential transcription of the mating-type genes with a pattern complementary to that of H. sinensis Strain L0106. Additional evidence is needed to explore a hybridization possibility between S. hepiali and H. sinensis, whether they are able to break the interspecific reproductive isolation. Genotypes #13~14 of O. sinensis feature large DNA segment reciprocal substitutions and genetic material recombination between 2 heterospecific parental fungi, H. sinensis and an AB067719-type fungus, indicating a possibility of hybridization or parasexuality. Our analysis provides important information at the genetic and transcriptional levels regarding the mating-type gene expression and reproduction physiology of O. sinensis in the sexual life of natural C. sinensis and offers crucial reproductive physiology evidence, to assist in the design of the artificial cultivation of C. sinensis to supplement the increasing scarcity of natural resource.
Cordyceps/genetics*
;
Genes, Mating Type, Fungal/genetics*
;
Reproduction/genetics*
3.Cloning and functional verification of PhAEP gene, a key enzyme for biosynthesis of heterophyllin A in Pseudostellaria heterophylla.
Mi LU ; Yang YANG ; Tao ZHOU ; Wei ZHENG ; Jiao XU ; Hua HE ; Guo-Ping SHU ; Qing-Song YUAN ; Wei-Ke JIANG
China Journal of Chinese Materia Medica 2023;48(7):1851-1857
This paper aimed to study the role of asparagine endopeptidase(AEP) gene in the biosynthesis mechanism of cyclic peptide compounds in Pseudostellaria heterophylla. The transcriptome database of P. heterophylla was systematically mined and screened, and an AEP gene, tentatively named PhAEP, was successfully cloned. The heterologous function verification by Nicotiana benthamiana showed that the expression of the gene played a role in the biosynthesis of heterophyllin A in P. heterophylla. Bioinformatics analysis showed that the cDNA of PhAEP was 1 488 bp in length, encoding 495 amino acids with a molecular weight of 54.72 kDa. The phylogenetic tree showed that the amino acid sequence encoded by PhAEP was highly similar to that of Butelase-1 in Clitoria ternatea, reaching 80%. The sequence homology and cyclase active site analysis revealed that the PhAEP enzyme may specifically hydrolyse the C-terminal Asn/Asp(Asx) site of the core peptide in the HA linear precursor peptide of P. heterophylla, thereby participating in the ring formation of the linear precursor peptide. The results of real-time quantitative polymerase chain reaction(RT-qPCR) showed that the expression level of PhAEP was the highest in fruits, followed by in roots, and the lowest in leaves. The heterophyllin A of P. heterophylla was detected in N. benthamiana that co-expressed PrePhHA and PhAEP genes instantaneously. In this study, the PhAEP gene, a key enzyme in the biosynthesis of heterophyllin A in P. heterophylla, has been successfully cloned, which lays a foundation for further analysis of the molecular mechanism of PhAEP enzyme in the biosynthesis of heterophyllin A in P. heterophylla and has important significance for the study of synthetic biology of cyclic peptide compounds in P. heterophylla.
Genes, vif
;
Phylogeny
;
Plant Leaves/genetics*
;
Peptides, Cyclic
;
Cloning, Molecular
;
Caryophyllaceae/genetics*
4.A potential mating-type biomarker to detect pathogenic Ganoderma species
Doris Lau ; Lee Weng Wah ; Chong Mei Ling ; Tee Sue Sean ; Jonathan Guyang Ling ; Anis Farhan Fatimi Ab Wahab ; Farah Diba Abu Bakar
Malaysian Journal of Microbiology 2022;18(3):331-337
Aims:
The basal stem rot disease in oil palm is caused by the pathogenic Ganoderma boninense, which is infectious after mating and forming dikaryotic hyphae. This study was aimed to generate a mating-type biomarker for the detection of pathogenic Ganoderma species.
Methodology and results:
Mating-type region of Ganoderma was amplified using polymerase chain reaction (PCR) and primers flanking the mating-type region of other basidiomycetes. Amplified fragments were sequenced and were identified as the Ganoderma pheromone receptor gene of matB locus called the gprb2 gene. Using this biomarker, the pheromone receptor gene was detected in a total of 107 pathogenic Ganoderma spp. while the gene was not detected in the non-pathogenic Ganoderma lucidum. Phylogenetic tree analyses of the gene fragment encoding the partial amino acid sequence of gprb2 showed clades of close evolutionary relationship among the 107 pathogenic Ganoderma spp. Phylogenetic analyses using deduced amino acid sequences of the Ganoderma pheromone receptor b2 gene, gprb2 with homologous pheromone receptors of other basidiomycetous fungi revealed high conservation of this pheromone receptor within their respective taxonomy.
Conclusion, significance and impact of study
A potential mating-type biomarker was successfully identified that could detect pathogenic Ganoderma spp. The research findings will be helpful in oil palm screening to detect pathogenic Ganoderma spp. and gain further insight into the role of the mating-type loci of Ganoderma towards its pathogenesis in causing the basal stem rot disease of oil palm.
Genes, Mating Type, Fungal
;
Ganoderma
5.Genetic Characteristics and Antimicrobial Susceptibility of
Yuan Yuan WANG ; Gui Lan ZHOU ; Ying LI ; Yi Xin GU ; Mu HE ; Shuang ZHANG ; Guo Qiang JI ; Jie YANG ; Miao WANG ; Hong Mei MA ; Mao Jun ZHANG
Biomedical and Environmental Sciences 2021;34(12):1024-1028
Aged
;
Animals
;
Arcobacter/genetics*
;
Chickens
;
Diarrhea/microbiology*
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Drug Resistance, Bacterial/genetics*
;
Genes, Bacterial
;
Gram-Negative Bacterial Infections/veterinary*
;
Humans
;
Male
;
Meat
;
Microbial Sensitivity Tests
;
Phylogeny
;
Poultry Diseases/microbiology*
;
Virulence
;
Virulence Factors/genetics*
6.Prevalence of Opportunistic Pathogens and Diversity of Microbial Communities in the Water System of a Pulmonary Hospital.
Wei TANG ; Yu MAO ; Qiu Yan LI ; Die MENG ; Ling CHEN ; Hong WANG ; Ren ZHU ; Wei Xian ZHANG
Biomedical and Environmental Sciences 2020;33(4):248-259
Objective:
Our objective was to investigate the occurrence of opportunistic pathogens and characterize the bacterial community structures in the water system of a pulmonary hospital.
Methods:
The water samples were collected from automatic and manual faucets in the consulting room, treatment room, dressing room, respiratory ward, and other non-medical rooms in three buildings of the hospital. Quantitative polymerase chain reaction was used to quantify the load of several waterborne opportunistic pathogens and related microorganisms, including spp., spp., and . Illumina sequencing targeting 16S rRNA genes was performed to profile bacterial communities.
Results:
The occurrence rates of spp., spp., and were 100%, 100%, and 76%, respectively in all samples. Higher occurrence rates of were observed in the outpatient service building (building 1, 91.7%) and respiration department and wards (building 2, 80%) than in the office building (building 3), where no was found. were more abundant in automatic faucets (average 2.21 × 10 gene copies/L) than in manual faucets (average 1.03 × 10 gene copies/mL) ( < 0.01). , , , , , and were the dominant bacterial phyla. Disinfectant residuals, nitrate, and temperature were found to be the key environmental factors driving microbial community structure shifts in water systems.
Conclusion
This study revealed a high level of colonization of water faucets by opportunistic pathogens and provided insight into the characteristics of microbial communities in a hospital water system and approaches to reduce risks of microbial contamination.
China
;
Drinking Water
;
microbiology
;
Genes, Bacterial
;
Hospitals
;
Legionella
;
isolation & purification
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Microbiota
;
Mycobacterium
;
isolation & purification
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Mycobacterium avium
;
isolation & purification
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RNA, Bacterial
;
analysis
;
RNA, Ribosomal, 16S
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analysis
;
Water Quality
;
Water Supply
7.Prediction of Chemotherapy-Induced Peripheral Neuropathy in Patients with Lymphoma and Myeloma: the Roles of Brain-Derived Neurotropic Factor Protein Levels and A Gene Polymorphism
David AZOULAY ; Sami GIRYES ; Roni NASSER ; Rivka SHARON ; Netanel A HOROWITZ
Journal of Clinical Neurology 2019;15(4):511-516
BACKGROUND AND PURPOSE: Brain-derived neurotrophic factor (BDNF) is a neuronal growth factor that plays an essential role in the maintenance of the nervous system. We have evaluated the peripheral blood protein levels of BDNF and the valine-to-methionine substitution at codon 66 (Val66Met) single-nucleotide polymorphism (SNP) as potential biomarkers for the early recognition of chemotherapy-induced peripheral neuropathy (CIPN) in non-Hodgkin lymphoma and multiple myeloma patients. METHODS: CIPN was assessed in 45 patients at the diagnosis and during vincristine or bortezomib-based therapy using objective [reduced version of the Total Neuropathy Score (TNSr)] and subjective (FACT-GOG-NTx) tools. Depression was assessed using the Patient Health Questionnaire-9 (PHQ-9) questionnaire. BDNF protein levels and the Val66Met SNP were determined using ELISA and Sanger sequencing. RESULTS: The pretreatment BDNF protein level was inversely correlated with the maximum TNSr, FACT-GOG-NTx, and PHQ-9 scores in both genotypes. BDNF patients with the Val/Val genotype demonstrated significantly higher maximum FACT-GOG-NTx and PHQ-9 scores than those with the Val/Met and Met/Met genotypes (Met-BNDF carriers). Correlations between PHQ-9 and TNSr score were found only in Met-BDNF carriers, suggesting that peripheral neuropathy and depression coincide in Met-BDNF carriers. CONCLUSIONS: Determining the BDNF protein levels before initiating chemotherapy might be a useful tool for CIPN risk assessment and preemptive dose modification. The present data should be validated in larger studies that include other neurotoxic agents.
Biomarkers
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Brain-Derived Neurotrophic Factor
;
Codon
;
Depression
;
Diagnosis
;
Drug Therapy
;
Enzyme-Linked Immunosorbent Assay
;
Genes, vif
;
Genotype
;
Humans
;
Lymphoma
;
Lymphoma, Non-Hodgkin
;
Multiple Myeloma
;
Nervous System
;
Neurons
;
Peripheral Nervous System Diseases
;
Risk Assessment
;
Vincristine
8.Oral Metagenomic Analysis Techniques
Journal of Dental Hygiene Science 2019;19(2):86-95
The modern era of microbial genome analysis began in earnest in the 2000s with the generalization of metagenomics and gene sequencing techniques. Studying complex microbial community such as oral cavity and colon by a pure culture is considerably ineffective in terms of cost and time. Therefore, various techniques for genomic analysis have been developed to overcome the limitation of the culture method and to explore microbial communities existing in the natural environment at the gene level. Among these, DNA fingerprinting analysis and microarray chip have been used extensively; however, the most recent method of analysis is metagenomics. The study summarily examined the overview of metagenomics analysis techniques, as well as domestic and foreign studies on disease genomics and cluster analysis related to oral metagenome. The composition of oral bacteria also varies across different individuals, and it would become possible to analyze what change occurs in the human body depending on the activity of bacteria living in the oral cavity and what causality it has with diseases. Identification, isolation, metabolism, and presence of functional genes of microorganisms are being identified for correlation analysis based on oral microbial genome sequencing. For precise diagnosis and treatment of diseases based on microbiome, greater effort is needed for finding not only the causative microorganisms, but also indicators at gene level. Up to now, oral microbial studies have mostly involved metagenomics, but if metatranscriptomic, metaproteomic, and metabolomic approaches can be taken together for assessment of microbial genes and proteins that are expressed under specific conditions, then doing so can be more helpful for gaining comprehensive understanding.
Bacteria
;
Colon
;
Dental Caries
;
Diagnosis
;
DNA Fingerprinting
;
Generalization (Psychology)
;
Genes, Microbial
;
Genome, Microbial
;
Genomics
;
Human Body
;
Metabolism
;
Metabolomics
;
Metagenome
;
Metagenomics
;
Methods
;
Microbiota
;
Mouth
9.Complete Sequence of the Mitochondrial Genome of Spirometra ranarum: Comparison with S. erinaceieuropaei and S. decipiens
Hyeong Kyu JEON ; Hansol PARK ; Dongmin LEE ; Seongjun CHOE ; Yeseul KANG ; Mohammed Mebarek BIA ; Sang Hwa LEE ; Keeseon S EOM
The Korean Journal of Parasitology 2019;57(1):55-60
This study was undertaken to determine the complete mitochondrial DNA sequence and structure of the mitochondrial genome of Spirometra ranarum, and to compare it with those of S. erinaceieuropaei and S. decipiens. The aim of this study was to provide information of the species level taxonomy of Spirometra spp. using the mitochondrial genomes of 3 Spirometra tapeworms. The S. ranarum isolate originated from Myanmar. The mitochondrial genome sequence of S. ranarum was compared with that of S. erinaceieuropaei (GenBank no. KJ599680) and S. decipiens (Gen-Bank no. KJ599679). The complete mtDNA sequence of S. ranarum comprised 13,644 bp. The S. ranarum mt genome contained 36 genes comprising 12 protein-coding genes, 22 tRNAs and 2 rRNAs. The mt genome lacked the atp8 gene, as found for other cestodes. All genes in the S. ranarum mitochondrial genome are transcribed in the same direction and arranged in the same relative position with respect to gene loci as found for S. erinaceieuropaei and S. decipiens mt genomes. The overall nucleotide sequence divergence of 12 protein-coding genes between S. ranarum and S. decipiens differed by 1.5%, and 100% sequence similarity was found in the cox2 and nad6 genes, while the DNA sequence divergence of the cox1, nad1, and nad4 genes of S. ranarum and S. decipiens was 2.2%, 2.1%, and 2.6%, respectively.
Base Sequence
;
Cestoda
;
Classification
;
DNA, Mitochondrial
;
Genes, vif
;
Genome
;
Genome, Mitochondrial
;
Myanmar
;
RNA, Transfer
;
Spirometra
10.Bleomycin Inhibits Proliferation via Schlafen-Mediated Cell Cycle Arrest in Mouse Alveolar Epithelial Cells
Soojin JANG ; Se Min RYU ; Jooyeon LEE ; Hanbyeol LEE ; Seok Ho HONG ; Kwon Soo HA ; Won Sun PARK ; Eun Taek HAN ; Se Ran YANG
Tuberculosis and Respiratory Diseases 2019;82(2):133-142
BACKGROUND: Idiopathic pulmonary fibrosis involves irreversible alveolar destruction. Although alveolar epithelial type II cells are key functional participants within the lung parenchyma, how epithelial cells are affected upon bleomycin (BLM) exposure remains unknown. In this study, we determined whether BLM could induce cell cycle arrest via regulation of Schlafen (SLFN) family genes, a group of cell cycle regulators known to mediate growth-inhibitory responses and apoptosis in alveolar epithelial type II cells. METHODS: Mouse AE II cell line MLE-12 were exposed to 1–10 µg/mL BLM and 0.01–100 µM baicalein (Bai), a G1/G2 cell cycle inhibitor, for 24 hours. Cell viability and levels of pro-inflammatory cytokines were analyzed by MTT and enzyme-linked immunosorbent assay, respectively. Apoptosis-related gene expression was evaluated by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Cellular morphology was determined after DAPI and Hoechst 33258 staining. To verify cell cycle arrest, propidium iodide (PI) staining was performed for MLE-12 after exposure to BLM. RESULTS: BLM decreased the proliferation of MLE-12 cells. However, it significantly increased expression levels of interleukin 6, tumor necrosis factor α, and transforming growth factor β1. Based on Hoechst 33258 staining, BLM induced condensation of nuclear and fragmentation. Based on DAPI and PI staining, BLM significantly increased the size of nuclei and induced G2/M phase cell cycle arrest. Results of qRT-PCR analysis revealed that BLM increased mRNA levels of BAX but decreased those of Bcl2. In addition, BLM/Bai increased mRNA levels of p53, p21, SLFN1, 2, 4 of Schlafen family. CONCLUSION: BLM exposure affects pulmonary epithelial type II cells, resulting in decreased proliferation possibly through apoptotic and cell cycle arrest associated signaling.
Animals
;
Apoptosis
;
Bisbenzimidazole
;
Bleomycin
;
Cell Cycle Checkpoints
;
Cell Cycle
;
Cell Line
;
Cell Survival
;
Cytokines
;
Enzyme-Linked Immunosorbent Assay
;
Epithelial Cells
;
Gene Expression
;
Genes, vif
;
Humans
;
Idiopathic Pulmonary Fibrosis
;
Interleukin-6
;
Lung
;
Mice
;
Propidium
;
RNA, Messenger
;
Transforming Growth Factors
;
Tumor Necrosis Factor-alpha


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