scholarly journals Comparative Genomics Analyses Support the Reclassification of Bisgaard Taxon 40 as Mergibacter gen. nov., With Mergibacter septicus sp. nov. as Type Species: Novel Insights Into the Phylogeny and Virulence Factors of a Pasteurellaceae Family Member Associated With Mortality Events in Seabirds

2021 ◽  
Vol 12 ◽  
Author(s):  
Eliana De Luca ◽  
Sonsiray Álvarez-Narváez ◽  
Grazieli Maboni ◽  
Rodrigo P. Baptista ◽  
Nicole M. Nemeth ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Type Species ◽  
Genomic Analysis ◽  
Phylogenetic Position ◽  
Comparative Genomic ◽  
The Novel ◽  
Mortality Event ◽  
Antimicrobial Susceptibility Profile ◽  
Antimicrobial Resistance Genes ◽  
Phenotypic And Genetic Characterization

The Pasteurellaceae family has been associated with fatal diseases in numerous avian species. Several new taxa within this family, including Bisgaard taxon 40, have been recently described in wild birds, but their genomic characteristics and pathogenicity are not well understood. We isolated Bisgaard taxon 40 from four species of seabirds, including one sampled during a mass, multi-species mortality event in Florida, United States. Here, we present a comprehensive phenotypic and genetic characterization of Bisgaard taxon 40 and comparative genomic analysis with reference strains from the Pasteurellaceae family, aiming at determining its phylogenetic position, antimicrobial susceptibility profile, and identifying putative virulence factors. In silico multilocus sequence-based and whole-genome-based phylogenetic analysis clustered all Bisgaard taxon 40 strains together on a distinct branch separated from the other members of the Pasteurellaceae family, indicating that Bisgaard taxon 40 could represent a new genus. These findings were further supported by protein similarity analyses using the concatenation of 31 conserved proteins and other taxonomic approaches such as the percentage of conserved protein test. Additionally, several putative virulence factors were identified, including those associated with adhesion (capsule, ompA, ompH) and colonization (exbD, fur, galU, galE, lpxA, lpxC, and kdsA) of the host and a cytolethal distending toxin (cdt), which may have played a role in disease development leading to the mortality event. Considerably low minimum inhibitory concentrations (MICs) were found for all the drugs tested, in concordance with the absence of antimicrobial resistance genes in these genomes. The novel findings of this study highlight genomic and phenotypic characteristics of this bacterium, providing insights into genome evolution and pathogenicity. We propose a reclassification of these organisms within the Pasteurellaceae family, designated as Mergibacter gen. nov., with Mergibacter septicus sp. nov. as the type species. The type strain is Mergibacter septicus A25201T (=DSM 112696).

scholarly journals Evolutionary Divergence of the Novel Staphylococcal Species Staphylococcus argenteus

2021 ◽  
Vol 12 ◽  
Author(s):  
Shi Wu ◽  
Rui Pang ◽  
Jiahui Huang ◽  
Feng Zhang ◽  
Zhihe Cai ◽  
...  
Keyword(s):  
Genomic Analysis ◽  
Comparative Genomic ◽  
Evolutionary Divergence ◽  
The Novel ◽  
Staphylococcal Species ◽  
Comprehensive Information ◽  
Antimicrobial Resistance Genes ◽  
Invasive Infections ◽  
Genomic Studies ◽  
Epidemiological Characteristics

Currently, invasive infections caused by Staphylococcus argenteus, which is a recently named staphylococcal species, are increasingly reported worldwide. However, only a few genomic studies of S. argenteus have offered comprehensive information regarding its genetic diversity, epidemiological characteristics, antimicrobial resistance genes (ARGs), virulence genes and other profiles. Here, we describe a comparative genomic analysis by population structure, pangenome, panmobilome, region-specific accessory genes confer an adaptive advantage in 153 S. argenteus strains which comprised 24 strains sequenced in this study and 129 strains whose genome sequences were available from GenBank. As a result, the population of S. argenteus comprised seven genetically distinct clades, including two major clades (C1 and C2), with distinct isolation source patterns. Pangenome analysis revealed that S. argenteus has an open pangenome composed of 7,319 genes and a core genome composed of 1,508 genes. We further determined the distributions of 75 virulence factors (VFs) and 30 known ARGs and identified at least four types of plasmids and 93 complete or partial putative prophages. It indicate that S. argenteus may show a similar level of pathogenicity to that of S. aureus. This study also provides insights into the evolutionary divergence of this pathogen, indicating that the geographical distribution was a potential driving force behind the evolutionary divergence of S. argenteus. The preferential horizontal acquisition of particular elements, such as staphylococcal cassette chromosome mec elements and plasmids, was observed in specific regions, revealing potential gene exchange between S. argenteus strains and local S. aureus strains. Moreover, multiple specific genes related to environmental adaptation were identified in strains isolated from East Asia. However, these findings may help promote our understanding of the evolutionary divergence of this bacterium at a high genetic resolution by providing insights into the epidemiology of S. argenteus and may help combat its spread.

scholarly journals Comparative Genomic Analysis of 450 Strains of Salmonella enterica Isolated from Diseased Animals

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1025
Author(s):  
Shaohua Zhao ◽  
Cong Li ◽  
Chih-Hao Hsu ◽  
Gregory H. Tyson ◽  
Errol Strain ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Bacterial Infections ◽  
Genomic Analysis ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Comparative Genomic ◽  
Salmonella Infections ◽  
Antimicrobial Resistance Genes ◽  
Salmonella Pathogenicity Islands ◽  
Shed Light

Salmonella is a leading cause of bacterial infections in animals and humans. We sequenced a collection of 450 Salmonella strains from diseased animals to better understand the genetic makeup of their virulence and resistance features. The presence of Salmonella pathogenicity islands (SPIs) varied by serotype. S. Enteritidis carried the most SPIs (n = 15), while S. Mbandaka, S. Cerro, S. Meleagridis, and S. Havana carried the least (n = 10). S. Typhimurium, S. Choleraesuis, S. I 4,5,12:i:-, and S. Enteritidis each contained the spv operon on IncFII or IncFII-IncFIB hybrid plasmids. Two S. IIIa carried a spv operon with spvD deletion on the chromosome. Twelve plasmid types including 24 hybrid plasmids were identified. IncA/C was frequently associated with S. Newport (83%) and S. Agona (100%) from bovine, whereas IncFII (100%), IncFIB (100%), and IncQ1 (94%) were seen in S. Choleraesuis from swine. IncX (100%) was detected in all S. Kentucky from chicken. A total of 60 antimicrobial resistance genes (ARGs), four disinfectant resistances genes (DRGs) and 33 heavy metal resistance genes (HMRGs) were identified. The Salmonella strains from sick animals contained various SPIs, resistance genes and plasmid types based on the serotype and source of the isolates. Such complicated genomic structures shed light on the strain characteristics contributing to the severity of disease and treatment failures in Salmonella infections, including those causing illnesses in animals.

Characterization, Pathogenicity, Phylogeny, and Comparative Genomic Analysis of Pseudomonas tolaasii Strains Isolated from Various Mushrooms in China

2021 ◽  
Author(s):  
Zhenghui Liu ◽  
Yitong Zhao ◽  
Frederick Leo Sossah ◽  
Benjamin Azu Okorley ◽  
Daniel G. Amoako ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Genomic Analysis ◽  
Gene Families ◽  
Effective Control ◽  
Economic Losses ◽  
Comparative Genomic ◽  
Bacterial Strains ◽  
Secretion Systems ◽  
Pseudomonas Tolaasii ◽  
Antimicrobial Resistance Genes

Since 2016, devastating bacterial blotch affecting the fruiting bodies of Agaricus bisporus, Cordyceps militaris, Flammulina filiformis, and Pleurotus ostreatus in China has caused severe economic losses. We isolated 102 bacterial strains and characterized them polyphasically. We identified the causal agent as Pseudomonas tolaasii and confirmed the pathogenicity of the strains. A host range test further confirmed the pathogen’s ability to infect multiple hosts. This is the first report in China of bacterial blotch in C. militaris caused by P. tolaasii. Whole-genome sequences were generated for three strains: Pt11 (6.48 Mb), Pt51 (6.63 Mb), and Pt53 (6.80 Mb), and pangenome analysis was performed with 13 other publicly accessible P. tolaasii genomes to determine their genetic diversity, virulence, antibiotic resistance, and mobile genetic elements. The pangenome of P. tolaasii is open, and many more gene families are likely to emerge with further genome sequencing. Multilocus sequence analysis using the sequences of four common housekeeping genes (glns, gyrB, rpoB, and rpoD) showed high genetic variability among the P. tolaasii strains, with 115 strains clustered into a monophyletic group. The P. tolaasii strains possess various genes for secretion systems, virulence factors, carbohydrate-active enzymes, toxins, secondary metabolites, and antimicrobial resistance genes that are associated with pathogenesis and adapted to different environments. The myriad of insertion sequences, integrons, prophages, and genome islands encoded in the strains may contribute to genome plasticity, virulence, and antibiotic resistance. These findings advance understanding of the determinants of virulence, which can be targeted for the effective control of bacterial blotch disease.

scholarly journals Novel start codons introduce novel coding sequences in the human genomes

2020 ◽  
Author(s):  
He Zhang ◽  
Yang Xie
Keyword(s):  
Translation Initiation ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Human Populations ◽  
The Novel ◽  
Coding Sequences ◽  
Human Genomes ◽  
High Level ◽  
Selection Signal ◽  
Human Specific

AbstractStart-gain mutations can introduce novel start codons and generate novel coding sequences that may affect the function of genes. In this study, we systematically investigated the novel start codons that were either polymorphic or fixed in the human genomes. 829 polymorphic start-gain SNVs were identified in the human populations, and the novel start codons introduced by these SNVs have significantly higher activity in translation initiation. Some of these start-gain SNVs were reported to be associated with phenotypes and diseases in previous studies. By comparative genomic analysis, we found 26 human-specific start codons that were fixed after the divergence between the human and chimpanzee, and high-level translation initiation activity was observed on them. The negative selection signal was detected in the novel coding sequences introduced by these human-specific start codons, indicating the important function of these novel coding sequences. This study reveals start-gain mutations are keeping appearing in the human genomes during the evolution and may be important sources altering the function of genes which may further affect the phenotypes or cause diseases.

scholarly journals Sequencing and Comparative Genomic Analysis of pK29, a 269-Kilobase Conjugative Plasmid Encoding CMY-8 and CTX-M-3 β-Lactamases in Klebsiella pneumoniae

2007 ◽  
Vol 51 (8) ◽  
pp. 3004-3007 ◽  
Author(s):  
Ying-Tsong Chen ◽  
Tsai-Ling Lauderdale ◽  
Tsai-Lien Liao ◽  
Yih-Ru Shiau ◽  
Hung-Yu Shu ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Resistance Genes ◽  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Conjugative Plasmid ◽  
Comparative Genomic ◽  
Antimicrobial Resistance Genes ◽  
Genomic Analyses ◽  
The Common

ABSTRACT A 269-kilobase conjugative plasmid, pK29, from a Klebsiella pneumoniae strain was sequenced. The plasmid harbors multiple antimicrobial resistance genes, including those encoding CMY-8 AmpC-type and CTX-M-3 extended-spectrum β-lactamases in the common backbone of IncHI2 plasmids. Mechanisms for dissemination of the resistance genes are highlighted in comparative genomic analyses.

scholarly journals Lichenicola cladoniae gen. nov., sp. nov., a member of the family Acetobacteraceae isolated from an Antarctic lichen

2020 ◽  
Vol 70 (11) ◽  
pp. 5918-5925 ◽  
Author(s):  
Hyun-Ju Noh ◽  
Seung Chul Shin ◽  
Yerin Park ◽  
Ahyoung Choi ◽  
Kiwoon Baek ◽  
...  
Keyword(s):  
Type Species ◽  
Genomic Analysis ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Respiratory Quinone ◽  
Content Type ◽  
Link Type ◽  
The Family ◽  
Nitrate And Nitrite

Two Gram-stain-negative, facultative anaerobic, chemoheterotrophic, pink-coloured, rod-shaped and non-motile bacterial strains, PAMC 26568 and PAMC 26569T, were isolated from an Antarctic lichen. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains PAMC 26568 and PAMC 26569T belong to the family Acetobacteraceae and the most closely related species are Gluconacetobacter takamatsuzukensis (96.1 %), Gluconacetobacter tumulisoli (95.9 %) and Gluconacetobacter sacchari (95.7 %). Phylogenomic and genomic relatedness analyses showed that strains PAMC 26568 and PAMC 26569T are clearly distinguished from other genera in the family Acetobacteraceae by average nucleotide identity values (<72.8 %) and the genome-to-genome distance values (<22.5 %). Genomic analysis revealed that strains PAMC 26568 and PAMC 26569T do not contain genes involved in atmospheric nitrogen fixation and utilization of sole carbon compounds such as methane and methanol. Instead, strains PAMC 26568 and PAMC 26569T possess genes to utilize nitrate and nitrite and certain monosaccharides and disaccharides. The major fatty acids (>10 %) are summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c; 40.3–40.4 %), C18 : 1 2OH (22.7–23.7 %) and summed feature 2 (C14 : 0 3OH and/or C16 : 1 iso I; 12.0 % in PAMC 26568). The major respiratory quinone is Q-10. The genomic DNA G+C content of PAMC 26568 and PAMC 26569T is 64.6 %. Their distinct phylogenetic position and some physiological characteristics distinguish strains PAMC 26568 and PAMC 26569T from other genera in the family Acetobacteraceae supporting the proposal of Lichenicola gen. nov., with the type species Lichenicola cladoniae sp. nov. (type strain, PAMC 26569T=KCCM 43315T=JCM 33604T).

scholarly journals Characterization of a blaNDM-1-Bearing IncHI5-Like Plasmid From Klebsiella pneumoniae of Infant Origin

2021 ◽  
Vol 11 ◽  
Author(s):  
Ziyi Liu ◽  
Ruifei Chen ◽  
Poshi Xu ◽  
Zhiqiang Wang ◽  
Ruichao Li
Keyword(s):  
Klebsiella Pneumoniae ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Genetic Composition ◽  
Carbapenem Resistant ◽  
Antimicrobial Resistance Genes ◽  
Genes Encoding ◽  
History Of ◽  
Core Genes

The spread of plasmid-mediated carbapenem-resistant clinical isolates is a serious threat to global health. In this study, an emerging NDM-encoding IncHI5-like plasmid from Klebsiella pneumoniae of infant patient origin was characterized, and the plasmid was compared to the available IncHI5-like plasmids to better understand the genetic composition and evolution of this emerging plasmid. Clinical isolate C39 was identified as K. pneumoniae and belonged to the ST37 and KL15 serotype. Whole genome sequencing (WGS) and analysis revealed that it harbored two plasmids, one of which was a large IncHI5-like plasmid pC39-334kb encoding a wide variety of antimicrobial resistance genes clustered in a single multidrug resistance (MDR) region. The blaNDM-1 gene was located on a ΔISAba125-blaNDM-1-bleMBL-trpF-dsbC structure. Comparative genomic analysis showed that it shared a similar backbone with four IncHI5-like plasmids and the IncHI5 plasmid pNDM-1-EC12, and these six plasmids differed from typical IncHI5 plasmids. The replication genes of IncHI5-like plasmids shared 97.06% (repHI5B) and 97.99% (repFIB-like) nucleotide identity with those of IncHI5 plasmids. Given that pNDM-1-EC12 and all IncHI5-like plasmids are closely related genetically, the occurrence of IncHI5-like plasmid is likely associated with the mutation of the replication genes of pNDM-1-EC12-like IncHI5 plasmids. All available IncHI5-like plasmids harbored 262 core genes encoding replication and maintenance functions and carried distinct MDR regions. Furthermore, 80% of them (4/5) were found in K. pneumoniae from Chinese nosocomial settings. To conclude, this study expands our knowledge of the evolution history of IncHI5-like plasmids, and more attention should be paid to track the evolution pathway of them among clinical, animal, and environmental settings.

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