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

The target gene sequences of the novel coronaviruses obtained by sequencing were compared with the reference sequences to analyze the genetic variation of the two cases of the novel coronaviruses from Inner Mongolia Autonomous Region in 2022 and to explore the sources of infection. The results showed that the two sequences belonged to different evolutionary branches, Delta (AY.122) and Omicron (BA.1.1), respectively. hCoV-19/Inner Mongolia/IVDC-591/2022 had 48 single nucleotide polymorphisms on the genome sequences, sharing 40 nucleotide mutation sites with a Mongolian strain; hCoV-19/Inner Mongolia/IVDC-592/2022 genome shared 57 nucleotide mutation sites with a UK strain, and the nucleotide mutation site identity was 100% (57/57). Phylogenetic analysis showed that the target gene sequences were not directly related to domestic novel coronavirus sequences during the same period, but were related to isolates from Europe and Mongolia.
Humans ; COVID-19 ; SARS-CoV-2/genetics* ; Phylogeny ; Genome, Viral ; Nucleotides ; Sequence Analysis

OBJECTIVE: A core genome multilocus sequence typing (cgMLST) scheme to genotype and identify potential risk clonal groups (CGs) in Proteus mirabilis. METHODS: In this work, we propose a publicly available cgMLST scheme for P. mirabilis using chewBBACA. In total 72 complete P. mirabilis genomes, representing the diversity of this species, were used to set up a cgMLST scheme targeting 1,842 genes, 635 unfinished (contig, chromosome, and scaffold) genomes were used for its validation. RESULTS: We identified a total of 205 CGs from 695 P. mirabilis strains with regional distribution characteristics. Of these, 159 unique CGs were distributed in 16 countries. CG20 and CG3 carried large numbers of shared and unique antibiotic resistance genes. Nine virulence genes ( papC, papD, papE, papF, papG, papH, papI, papJ, and papK) related to the P fimbrial operon that cause severe urinary tract infections were only found in CG20. These CGs require attention due to potential risks. CONCLUSION This research innovatively performs high-resolution molecular typing of P. mirabilis using whole-genome sequencing technology combined with a bioinformatics pipeline (chewBBACA). We found that the CGs of P. mirabilis showed regional distribution differences. We expect that our research will contribute to the establishment of cgMLST for P. mirabilis.
Genome, Bacterial ; Proteus mirabilis/genetics* ; Multilocus Sequence Typing ; Molecular Epidemiology ; Genotype

OBJECTIVE: To improve the understanding of the virome and bacterial microbiome in the wildlife rescue station of Poyang Lake, China. METHODS: Ten smear samples were collected in March 2019. Metagenomic sequencing was performed to delineate bacterial and viral diversity. Taxonomic analysis was performed using the Kraken2 and Bracken methods. A maximum-likelihood tree was constructed based on the RNA-dependent RNA polymerase (RdRp) region of picornavirus. RESULTS: We identified 363 bacterial and 6 viral families. A significant difference in microbial and viral abundance was found between samples S01-S09 and S10. In S01-S09, members of Flavobacteriia and Gammaproteobacteria were the most prevalent, while in S10, the most prevalent bacteria class was Actinomycetia. Among S01-S09, members of Myoviridae and Herelleviridae were the most prevalent, while the dominant virus family of S10 was Picornaviridae. The full genome of the pigeon mesivirus-like virus (NC-BM-233) was recovered from S10 and contained an open reading frame of 8,124 nt. It showed the best hit to the pigeon mesivirus 2 polyprotein, with 84.10% amino acid identity. Phylogenetic analysis showed that RdRp clustered into Megrivirus B. CONCLUSION This study provides an initial assessment of the bacteria and viruses in the cage-smeared samples, broadens our knowledge of viral and bacterial diversity, and is a way to discover potential pathogens in wild birds.
Animals ; Animals, Wild/genetics* ; Lakes ; Phylogeny ; Picornaviridae/genetics* ; Viruses/genetics* ; China ; Metagenomics ; Genome, Viral

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*

The target gene sequences of the novel coronaviruses obtained by sequencing were compared with the reference sequences to analyze the genetic variation of the two cases of the novel coronaviruses from Inner Mongolia Autonomous Region in 2022 and to explore the sources of infection. The results showed that the two sequences belonged to different evolutionary branches, Delta (AY.122) and Omicron (BA.1.1), respectively. hCoV-19/Inner Mongolia/IVDC-591/2022 had 48 single nucleotide polymorphisms on the genome sequences, sharing 40 nucleotide mutation sites with a Mongolian strain; hCoV-19/Inner Mongolia/IVDC-592/2022 genome shared 57 nucleotide mutation sites with a UK strain, and the nucleotide mutation site identity was 100% (57/57). Phylogenetic analysis showed that the target gene sequences were not directly related to domestic novel coronavirus sequences during the same period, but were related to isolates from Europe and Mongolia.
Humans ; COVID-19 ; SARS-CoV-2/genetics* ; Phylogeny ; Genome, Viral ; Nucleotides ; Sequence Analysis

COVID-19/genetics* ; Genome, Viral/genetics* ; Humans ; RNA, Viral/genetics* ; RNA-Seq ; SARS-CoV-2/genetics* ; Whole Genome Sequencing

Genome, Viral ; Humans ; Malaysia/epidemiology* ; Orthoreovirus/isolation & purification* ; Outpatients ; Pharynx/virology* ; Reoviridae Infections/epidemiology* ; Seroepidemiologic Studies

OBJECTIVE: To analyze the mutations in transcription regulatory sequences (TRSs) of coronaviruss (CoV) to provide the basis for exploring the patterns of SARS-CoV-2 transmission and outbreak. METHODS: A combined evolutionary and molecular functional analysis of all sets of publicly available genomic data of viruses was performed. RESULTS: A leader transcription regulatory sequence (TRS-L) usually comprises the first 60-70 nts of the 5' UTR in a CoV genome, and the body transcription regulatory sequences (TRS-Bs) are located immediately upstream of the genes other than ORF1a and 1b. In each CoV genome, the TRS-L and TRS-Bs share a specific consensus sequence, namely the TRS motif. Any changes of nucleotide residues in the TRS motifs are defined as TRS motif mutations. Mutations in the TRS-L or multiple TRS-Bs result in superattenuated variants. The spread of super-attenuated variants may cause an increase in asymptomatic or mild infections, prolonged incubation periods and a decreased detection rate of the viruses, thus posing new challenges to SARS-CoV-2 prevention and control. The super-attenuated variants also increase their possibility of long-term coexistence with humans. The Delta variant is significantly different from all the previous variants and may lead to a large-scale transmission. The Delta variant (B.1.617.2) with TRS motif mutation has already appeared and shown signs of spreading in Singapore, which, and even the Southeast Asia, may become the new epicenter of the next wave of SARS-CoV-2 outbreak. CONCLUSION TRS motif mutation will occur in all variants of SARS-CoV-2 and may result in super-attenuated variants. Only super-attenuated variants with TRS motif mutations will eventually lose the abilities of cross-species transmission and causing outbreaks.
COVID-19/virology* ; Genome, Viral ; Humans ; Mutation ; SARS-CoV-2/genetics*

Aims: The cucumber mosaic virus (CMV) is categorized under the genus Cucumovirus and family Bromoviridae. This virus is known to infect over 1200 plant species from 100 families, including ornamental and horticultural plants. In this study, we pioneered a global genome comparison to decipher the unknown orchestrators behind the virulence and pathogenicity of CMV via the discovery of important single nucleotide polymorphic markers. Methodology and results: As a result, the genome size was found to be a potential preliminary country-specific marker for South Korea and the GC content can be utilized to preliminarily differentiate Turkey isolates from the others. The motif analysis as well as whole genome and coat protein phylogenetic trees were unable to form country-specific clusters. However, the coat protein haplotype analysis had successfully unconcealed country-specific single nucleotide polymorphic markers for Iran, Turkey and Japan isolates. Moreover, coat protein modelling and gene ontology prediction depicted high conservation across CMV isolates from different countries. Conclusion, significance and impact of study The country-specific single nucleotide polymorphic markers unearthed in this study may provide significant data towards the profiling of varying virulence and pathogenicity of CMV across the globe in time to combat the yield loss driven by this virus thru the most efficacious biological control measures in the future.
Cucumovirus--genetics ; Genome, Microbial