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518900.9965Genomic analysis of halophilic bacterium, Lentibacillus sp. CBA3610, derived from human feces. BACKGROUND: Lentibacillus species are gram variable aerobic bacteria that live primarily in halophilic environments. Previous reports have shown that bacteria belonging to this species are primarily isolated from salty environments or food. We isolated a bacterial strain CBA3610, identified as a novel species of the genus Lentibacillus, from a human fecal sample. In this report, the whole genome sequence of Lentibacillus sp. CBA3610 is presented, and genomic analyses are performed. RESULTS: Complete genome sequence of strain CBA3610 was obtained through PacBio RSII and Illumina HiSeq platforms. The size of genome is 4,035,571 bp and genes estimated to be 4714 coding DNA sequences and 64 tRNA and 17 rRNA were identified. The phylogenetic analysis confirmed that it belongs to the genus Lentibacillus. In addition, there were genes related to antibiotic resistance and virulence, and genes predicted as CRISPR and prophage were also identified. Genes related to osmotic stress were found according to the characteristics of halophilic bacterium. Genomic differences from other Lentibacillus species were also confirmed through comparative genomic analysis. CONCLUSIONS: Strain CBA3610 is predicted to be a novel candidate species of Lentibacillus through phylogenetic analysis and comparative genomic analysis with other species in the same genus. This strain has antibiotic resistance gene and pathogenic genes. In future, the information derived from the results of several genomic analyses of this strain is thought to be helpful in identifying the relationship between halophilic bacteria and human gut microbiota.202134162403
514710.9963Multiscale comparative pathogenomic analysis of Vibrio anguillarum linking serotype diversity, genomic plasticity and pathogenicity. Vibrio anguillarum is a major marine fish pathogen causing high mortality and potential zoonotic risks. Understanding its genomic diversity, virulence factors, and antibiotic resistance is crucial for aquaculture disease management. In this study, a comparative pan-genomic analysis of 16 V. anguillarum strains was conducted to examine core and accessory genome diversity, virulence factors, and antibiotic resistance mechanisms. The phylogenetic analysis was conducted using six core genes and SNPs to evaluate evolutionary relationships and pathogenic traits. The core genome contained 2,038 unique ORFs, while the accessory genome had 5,197 cloud genes, confirming an open pangenome. This study identified 118 pathogenic genomic islands, antibiotic resistance genes (tetracycline, quinolone, and carbapenem), and virulence factors, including type VI secretion system (T6SS) components and RTX toxins (hcp-2, vipB/mglB, rtxC). Core genes such as ftsI uncovered substantial evolutionary divergence among species, identifying more than 150 distinct SNPs. Phylogenetic analysis showed serotype-specific clustering, with O1 strains displaying genetic homogeneity, whereas O2 and O3 exhibited divergence, suggesting distinct evolutionary adaptations influencing pathogenicity and ecological interactions. These findings provide primary insights for developing molecular markers and targeted treatments for aquaculture pathogens.202540854641
514320.9962Genomic Insights Into the Pathogenicity of a Novel Biofilm-Forming Enterococcus sp. Bacteria (Enterococcus lacertideformus) Identified in Reptiles. Whole genome analysis of a novel species of enterococci, Enterococcus lacertideformus, causing multi-systemic and invariably fatal disease in critically endangered Christmas Island reptiles was undertaken to determine the genetic elements and potential mechanisms conferring its pathogenic nature, biofilm-forming capabilities, immune recognition avoidance, and inability to grow in vitro. Comparative genomic analyses with related and clinically significant enterococci were further undertaken to infer the evolutionary history of the bacterium and identify genes both novel and absent. The genome had a G + C content of 35.1%, consisted of a circular chromosome, no plasmids, and was 2,419,934 bp in length (2,321 genes, 47 tRNAs, and 13 rRNAs). Multi-locus sequence typing (MLST), and single nucleotide polymorphism (SNP) analysis of multiple E. lacertideformus samples revealed they were effectively indistinguishable from one another and highly clonal. E. lacertideformus was found to be located within the Enterococcus faecium species clade and was closely related to Enterococcus villorum F1129D based on 16S rDNA and MLST house-keeping gene analysis. Antimicrobial resistance (DfreE, EfrB, tetM, bcrRABD, and sat4) and virulence genes (Fss3 and ClpP), and genes conferring tolerance to metals and biocides (n = 9) were identified. The detection of relatively few genes encoding antimicrobial resistance and virulence indicates that this bacterium may have had no exposure to recently developed and clinically significant antibiotics. Genes potentially imparting beneficial functional properties were identified, including prophages, insertion elements, integrative conjugative elements, and genomic islands. Functional CRISPR-Cas arrays, and a defective prophage region were identified in the genome. The study also revealed many genomic loci unique to E. lacertideformus which contained genes enriched in cell wall/membrane/envelop biogenesis, and carbohydrate metabolism and transport functionality. This finding and the detection of putative enterococcal biofilm determinants (EfaAfs, srtC, and scm) may underpin the novel biofilm phenotype observed for this bacterium. Comparative analysis of E. lacertideformus with phylogenetically related and clinically significant enterococci (E. villorum F1129D, Enterococcus hirae R17, E. faecium AUS0085, and Enterococcus faecalis OG1RF) revealed an absence of genes (n = 54) in E. lacertideformus, that encode metabolic functionality, which potentially hinders nutrient acquisition and/or utilization by the bacterium and precludes growth in vitro. These data provide genetic insights into the previously determined phenotype and pathogenic nature of the bacterium.202133737921
546830.9961Whole-genome sequence of a putative pathogenic Bacillus sp. strain SD-4 isolated from cattle feed. OBJECTIVES: The present study describes the draft genome sequence of a novel Bacillus sp. strain SD-4 isolated from animal feed. The study aims to get a deeper insight into antimicrobial resistance and secondary metabolite biosynthetic gene clusters (BGCs) and the association between them. METHODS: The strain SD-4 was preliminarily evaluated for antibacterial activities, motility, biofilm formation, and enterotoxin production using in vitro assays. The genome of strain SD-4 was sequenced using the Illumina HiSeq 2500 platform with paired-end reads. The reads were assembled and annotated using SPAdes and PGAP, respectively. The genome was further analysed using several bioinformatics tools, including TYGS, AntiSMASH, RAST, PlasmidFinder, VFDB, VirulenceFinder, CARD, PathogenFinder, MobileElement finder, IslandViewer, and CRISPRFinder. RESULTS: In vitro assays showed that the strain is motile, synthesises biofilm, and produces an enterotoxin and antibacterial metabolites. The genome analysis revealed that the strain SD-4 carries antimicrobial resistance genes (ARGs), virulence factors, and beneficial secondary metabolite BGCs. Further genome analysis showed interesting genome architectures containing several mobile genetic elements, including two plasmid replicons (repUS22 and rep20), five prophages, and at least four genomic islands (GIs), including one Listeria pathogenicity island LIPI-1. Moreover, the strain SD-4 is identified as a putative human pathogen. CONCLUSION: The genome of strain SD-4 harbours several BGCs coding for biologically active metabolites. It also contains antimicrobial resistance genes and is identified as a potential human pathogen. These results can be used to better comprehend antibiotic resistance in environmental bacteria that are not influenced by human intervention.202235413450
515340.9961Single-Molecule Sequencing (PacBio) of the Staphylococcus capitis NRCS-A Clone Reveals the Basis of Multidrug Resistance and Adaptation to the Neonatal Intensive Care Unit Environment. The multi-resistant Staphylococcus capitis clone NRCS-A has recently been described as a major pathogen causing nosocomial, late-onset sepsis (LOS) in preterm neonates worldwide. NRCS-A representatives exhibit an atypical antibiotic resistance profile. Here, the complete closed genome (chromosomal and plasmid sequences) of NRCS-A prototype strain CR01 and the draft genomes of three other clinical NRCS-A strains from Australia, Belgium and the United Kingdom are annotated and compared to available non-NRCS-A S. capitis genomes. Our goal was to delineate the uniqueness of the NRCS-A clone with respect to antibiotic resistance, virulence factors and mobile genetic elements. We identified 6 antimicrobial resistance genes, all carried by mobile genetic elements. Previously described virulence genes present in the NRCS-A genomes are shared with the six non-NRCS-A S. capitis genomes. Overall, 63 genes are specific to the NRCS-A lineage, including 28 genes located in the methicillin-resistance cassette SCCmec. Among the 35 remaining genes, 25 are of unknown function, and 9 correspond to an additional type I restriction modification system (n = 3), a cytosine methylation operon (n = 2), and a cluster of genes related to the biosynthesis of teichoic acids (n = 4). Interestingly, a tenth gene corresponds to a resistance determinant for nisin (nsr gene), a bacteriocin secreted by potential NRCS-A strain niche competitors in the gut microbiota. The genomic characteristics presented here emphasize the contribution of mobile genetic elements to the emergence of multidrug resistance in the S. capitis NRCS-A clone. No NRCS-A-specific known virulence determinant was detected, which does not support a role for virulence as a driving force of NRCS-A emergence in NICUs worldwide. However, the presence of a nisin resistance determinant on the NRCS-A chromosome, but not in other S. capitis strains and most coagulase-negative representatives, might confer a competitive advantage to NRCS-A strains during the early steps of gut colonization in neonates. This suggests that the striking adaptation of NRCS-A to the NICU environment might be related to its specific antimicrobial resistance and also to a possible enhanced ability to challenge competing bacteria in its ecological niche.201628018320
179650.9961Plasmids of Shigella flexneri serotype 1c strain Y394 provide advantages to bacteria in the host. BACKGROUND: Shigella flexneri has an extremely complex genome with a significant number of virulence traits acquired by mobile genetic elements including bacteriophages and plasmids. S. flexneri serotype 1c is an emerging etiological agent of bacillary dysentery in developing countries. In this study, the complete nucleotide sequence of two plasmids of S. flexneri serotype 1c strain Y394 was determined and analysed. RESULTS: The plasmid pINV-Y394 is an invasive or virulence plasmid of size 221,293 bp composed of a large number of insertion sequences (IS), virulence genes, regulatory and maintenance genes. Three hundred and twenty-eight open reading frames (ORFs) were identified in pINV-Y394, of which about a half (159 ORFs) were identified as IS elements. Ninety-seven ORFs were related to characterized genes (majority of which are associated with virulence and their regulons), and 72 ORFs were uncharacterized or hypothetical genes. The second plasmid pNV-Y394 is of size 10,866 bp and encodes genes conferring resistance against multiple antibiotics of clinical importance. The multidrug resistance gene cassette consists of tetracycline resistance gene tetA, streptomycin resistance gene strA-strB and sulfonamide-resistant dihydropteroate synthase gene sul2. CONCLUSIONS: These two plasmids together play a key role in the fitness of Y394 in the host environment. The findings from this study indicate that the pathogenic S. flexneri is a highly niche adaptive pathogen which is able to co-evolve with its host and respond to the selection pressure in its environment.201931035948
514960.9961Complete genome sequence and comparative genomic analysis of Enterococcus faecalis EF-2001, a probiotic bacterium. Enterococcus faecalis is a common human gut commensal bacterium. While some E. faecalis strains are probiotic, others are known to cause opportunistic infections, and clear distinction between these strains is difficult using traditional taxonomic approaches. In this study, we completed the genome sequencing of EF-2001, a probiotic strain, using our in-house hybrid assembly approach. Comparative analysis showed that EF-2001 was devoid of cytolysins, major factors associated with pathogenesis, and was phylogenetically distant from pathogenic E. faecalis V583. Genomic analysis of strains with a publicly available complete genome sequence predicted that drug-resistance genes- dfrE, efrA, efrB, emeA, and lsaA were present in all strains, and EF-2001 lacked additional drug-resistance genes. Core- and pan-genome analyses revealed a higher degree of genomic fluidity. We found 49 genes specific to EF-2001, further characterization of which may provide insights into its diverse biological activities. Our comparative genomic analysis approach could help predict the pathogenic or probiotic potential of E. faecalis leading to an early distinction based on genome sequences.202133771633
179570.9960Accessory genome of the multi-drug resistant ocular isolate of Pseudomonas aeruginosa PA34. Bacteria can acquire an accessory genome through the horizontal transfer of genetic elements from non-parental lineages. This leads to rapid genetic evolution allowing traits such as antibiotic resistance and virulence to spread through bacterial communities. The study of complete genomes of bacterial strains helps to understand the genomic traits associated with virulence and antibiotic resistance. We aimed to investigate the complete accessory genome of an ocular isolate of Pseudomonas aeruginosa strain PA34. We obtained the complete genome of PA34 utilising genome sequence reads from Illumina and Oxford Nanopore Technology followed by PCR to close any identified gaps. In-depth genomic analysis was performed using various bioinformatics tools. The susceptibility to heavy metals and cytotoxicity was determined to confirm expression of certain traits. The complete genome of PA34 includes a chromosome of 6.8 Mbp and two plasmids of 95.4 Kbp (pMKPA34-1) and 26.8 Kbp (pMKPA34-2). PA34 had a large accessory genome of 1,213 genes and had 543 unique genes not present in other strains. These exclusive genes encoded features related to metal and antibiotic resistance, phage integrase and transposons. At least 24 genomic islands (GIs) were predicated in the complete chromosome, of which two were integrated into novel sites. Eleven GIs carried virulence factors or replaced pathogenic genes. A bacteriophage carried the aminoglycoside resistance gene (AAC(3)-IId). The two plasmids carried other six antibiotic resistance genes. The large accessory genome of this ocular isolate plays a large role in shaping its virulence and antibiotic resistance.201930986237
519980.9959Whole genome sequencing uncovers a novel IND-16 metallo-β-lactamase from an extensively drug-resistant Chryseobacterium indologenes strain J31. BACKGROUND: Chryseobacterium indologenes is an emerging opportunistic pathogen in hospital-acquired infection, which is intrinsically resistant to most antimicrobial agents against gram-negative bacteria. In the purpose of extending our understanding of the resistance mechanism of C. indologenes, we sequenced and analyzed the genome of an extensively antibiotic resistant C. indologenes strain, isolated from a Chinese prostate cancer patient. We also investigated the presence of antibiotic resistance genes, particularly metallo-β-lactamase (MBL) genes, and performed a comparative genomic analysis with other Chryseobacterium species. RESULTS: 16s rRNA sequencing indicated the isolate belongs to C. indologenes. We assembled a total of 1095M bp clean-filtered reads into 171 contigs by de novo assembly. The draft genome of C. indologenes J31 consisted of 5,830,795 bp with a GC content of 36.9 %. RAST analysis revealed the genome contained 5196 coding sequences (CDSs), 28 rRNAs, 81 tRNAs and 114 pseudogenes. We detected 90 antibiotic resistance genes from different drug classes in the whole genome. Notably, a novel bla(IND) allele bla(IND-16) was identified, which shared 99 % identity with bla(IND-8) and bla(IND-10). By comparing strain J31 genome to the closely four related neighbors in the genus Chryseobacterium, we identified 2634 conserved genes, and 1449 unique genes. CONCLUSIONS: In this study, we described the whole genome sequence of C. indologenes strain J31. Numerous resistance determinants were detected in the genome and might be responsible for the extensively antibiotic resistance of this strain. Comparative genomic analysis revealed the presence of considerable strain-specific genes which would contribute to the distinctive characteristics of strain J31. Our study provides the insight of the multidrug resistance mechanism in genus Chryseobacterium.201627785154
546490.9959Genomic and resistome analysis of Alcaligenes faecalis strain PGB1 by Nanopore MinION and Illumina Technologies. BACKGROUND: Drug-resistant bacteria are important carriers of antibiotic-resistant genes (ARGs). This fact is crucial for the development of precise clinical drug treatment strategies. Long-read sequencing platforms such as the Oxford Nanopore sequencer can improve genome assembly efficiency particularly when they are combined with short-read sequencing data. RESULTS: Alcaligenes faecalis PGB1 was isolated and identified with resistance to penicillin and three other antibiotics. After being sequenced by Nanopore MinION and Illumina sequencer, its entire genome was hybrid-assembled. One chromosome and one plasmid was assembled and annotated with 4,433 genes (including 91 RNA genes). Function annotation and comparison between strains were performed. A phylogenetic analysis revealed that it was closest to A. faecalis ZD02. Resistome related sequences was explored, including ARGs, Insert sequence, phage. Two plasmid aminoglycoside genes were determined to be acquired ARGs. The main ARG category was antibiotic efflux resistance and β-lactamase (EC 3.5.2.6) of PGB1 was assigned to Class A, Subclass A1b, and Cluster LSBL3. CONCLUSIONS: The present study identified the newly isolated bacterium A. faecalis PGB1 and systematically annotated its genome sequence and ARGs.202235443609
5214100.9959Comparative genomic analysis of a new tellurite-resistant Psychrobacter strain isolated from the Antarctic Peninsula. The Psychrobacter genus is a cosmopolitan and diverse group of aerobic, cold-adapted, Gram-negative bacteria exhibiting biotechnological potential for low-temperature applications including bioremediation. Here, we present the draft genome sequence of a bacterium from the Psychrobacter genus isolated from a sediment sample from King George Island, Antarctica (3,490,622 bp; 18 scaffolds; G + C = 42.76%). Using phylogenetic analysis, biochemical properties and scanning electron microscopy the bacterium was identified as Psychrobacter glacincola BNF20, making it the first genome sequence reported for this species. P. glacincola BNF20 showed high tellurite (MIC 2.3 mM) and chromate (MIC 6.0 mM) resistance, respectively. Genome-wide nucleotide identity comparisons revealed that P. glacincola BNF20 is highly similar (>90%) to other uncharacterized Psychrobacter spp. such as JCM18903, JCM18902, and P11F6. Bayesian multi-locus phylogenetic analysis showed that P. glacincola BNF20 belongs to a polyphyletic clade with other bacteria isolated from polar regions. A high number of genes related to metal(loid) resistance were found, including tellurite resistance genetic determinants located in two contigs: Contig LIQB01000002.1 exhibited five ter genes, each showing putative promoter sequences (terACDEZ), whereas contig LIQB1000003.2 showed a variant of the terZ gene. Finally, investigating the presence and taxonomic distribution of ter genes in the NCBI's RefSeq bacterial database (5,398 genomes, as January 2017), revealed that 2,623 (48.59%) genomes showed at least one ter gene. At the family level, most (68.7%) genomes harbored one ter gene and 15.6% exhibited five (including P. glacincola BNF20). Overall, our results highlight the diverse nature (genetic and geographic diversity) of the Psychrobacter genus, provide insights into potential mechanisms of metal resistance, and exemplify the benefits of sampling remote locations for prospecting new molecular determinants.201829479501
475110.9958Genome analysis of Minibacterium massiliensis highlights the convergent evolution of water-living bacteria. Filtration usually eliminates water-living bacteria. Here, we report on the complete genome sequence of Minibacterium massiliensis, a beta-proteobacteria that was recovered from 0.22-mum filtered water used for patients in the hospital. The unexpectedly large 4,110,251-nucleotide genome sequence of M. massiliensis was determined using the traditional shotgun sequencing approach. Bioinformatic analyses shows that the M. massiliensis genome sequence illustrates characteristic features of water-living bacteria, including overrepresentation of genes encoding transporters and transcription regulators. Phylogenomic analysis based on the gene content of available bacterial genome sequences displays a congruent evolution of water-living bacteria from various taxonomic origins, principally for genes involved in energy production and conversion, cell division, chromosome partitioning, and lipid metabolism. This phylogenomic clustering partially results from lateral gene transfer, which appears to be more frequent in water than in other environments. The M. massiliensis genome analyses strongly suggest that water-living bacteria are a common source for genes involved in heavy-metal resistance, antibiotics resistance, and virulence factors.200717722982
5162120.9958Genomic identification and characterization of Streptococcus oralis group that causes intraamniotic infection. BACKGROUND: Intraamniotic infection is a cause of spontaneous preterm labor. Streptococcus mitis is a common pathogen identified in intraamniotic infection, with the possible route of hematogenous dissemination from the oral cavity or migration from the vaginal canal. However, there are a few reports on Streptococcus oralis, a member of the S. mitis group, as a cause of pathogen in intraamniotic infection. We reported herein whole genome sequencing and comparative genomic analysis of S. oralis strain RAOG5826 that causes intraamniotic infection. RESULTS: Streptococcus mitis was initially identified from amniotic fluid, vaginal swab, and fetal blood of a patient presenting with preterm prelabor rupture of membranes with intraamniotic infection by the use of conventional microbiological methods (biochemical phenotype, MALDI-ToF, 16 S rRNA). Subsequently, this strain was later identified as S. oralis RAOG5826 by whole-genome hybrid sequencing. Genes involved in macrolide and tetracycline resistance, namely ermB and tet(M), and mutations in penicillin-binding protein were present in the genome. Moreover, potential virulence genes were predicted and compared with other Streptococcal species. CONCLUSION: We reported a comprehensive genomic analysis of S. oralis, which causes intraamniotic infection. S. mitis was initially identified by conventional microbiological identification. However, whole-genome hybrid sequencing demonstrates S. oralis with complete profiles of antimicrobial resistance genes and potential virulence factors. This study highlights the limitations of traditional techniques and underscores the importance of genomic sequencing for accurate diagnosis and tailored antimicrobial treatment. The study also suggests that S. oralis may be an underestimated pathogen in intraamniotic infection.202541023353
6139130.9958Complete genome and two plasmids sequences of Lactiplantibacillus plantarum L55 for probiotic potentials. In this study, we report the complete genome sequence of Lactiplantibacillus plantarum L55, a probiotic strain of lactic acid bacteria isolated from kimchi. The genome consists of one circular chromosome (2,077,416 base pair [bp]) with a guanine cytosine (GC) content of 44.5%, and two circular plasmid sequences (54,267 and 19,592 bp, respectively). We also conducted a comprehensive analysis of the genome, which identified the presence of functional genes, genomic islands, and antibiotic-resistance genes. The genome sequence data presented in this study provide insights into the genetic basis of L. plantarum L55, which could be beneficial for the future development of probiotic applications.202338616876
5129140.9958Complete genome sequences of Vibrio parahaemolyticus strains L2171 and L2181 associated with AHPND in Penaeus vannamei postlarvae by hybrid sequencing. Vibrio parahaemolyticus strains L2171 and L2181 were isolated from a Penaeus vannamei shrimp hatchery. Both strains carry the pVA plasmid harboring the PirAB genes encoding the binary PirAB toxins that cause the acute hepatopancreatic necrosis disease (AHPND) in cultured shrimp. The strains also harbor multidrug resistance (MDR) and a repertoire of virulence factor genes. Our goal was to determine their complete genome sequences and perform a comprehensive analysis of their genetic characteristics. Therefore, the genomes of two strains, which are highly virulent to shrimp were sequenced by Illumina and the PacBio platforms. These data contribute to a better understanding of V. parahaemolyticus and its role as a pathogen in commercially important species such as farmed shrimp, providing valuable insights for disease management in aquaculture.202540677256
5151150.9958Comparative Genome Analysis of Bacillus amyloliquefaciens Focusing on Phylogenomics, Functional Traits, and Prevalence of Antimicrobial and Virulence Genes. Bacillus amyloliquefaciens is a gram-positive, nonpathogenic, endospore-forming, member of a group of free-living soil bacteria with a variety of traits including plant growth promotion, production of antifungal and antibacterial metabolites, and production of industrially important enzymes. We have attempted to reconstruct the biogeographical structure according to functional traits and the evolutionary lineage of B. amyloliquefaciens using comparative genomics analysis. All the available 96 genomes of B. amyloliquefaciens strains were curated from the NCBI genome database, having a variety of important functionalities in all sectors keeping a high focus on agricultural aspects. In-depth analysis was carried out to deduce the orthologous gene groups and whole-genome similarity. Pan genome analysis revealed that shell genes, soft core genes, core genes, and cloud genes comprise 17.09, 5.48, 8.96, and 68.47%, respectively, which demonstrates that genomes are very different in the gene content. It also indicates that the strains may have flexible environmental adaptability or versatile functions. Phylogenetic analysis showed that B. amyloliquefaciens is divided into two clades, and clade 2 is further dived into two different clusters. This reflects the difference in the sequence similarity and diversification that happened in the B. amyloliquefaciens genome. The majority of plant-associated strains of B. amyloliquefaciens were grouped in clade 2 (73 strains), while food-associated strains were in clade 1 (23 strains). Genome mining has been adopted to deduce antimicrobial resistance and virulence genes and their prevalence among all strains. The genes tmrB and yuaB codes for tunicamycin resistance protein and hydrophobic coat forming protein only exist in clade 2, while clpP, which codes for serine proteases, is only in clade 1. Genome plasticity of all strains of B. amyloliquefaciens reflects their adaption to different niches.202134659348
1794160.9958Insights into the evolution of gene organization and multidrug resistance from Klebsiella pneumoniae plasmid pKF3-140. Plasmid-mediated transfer of drug-resistance genes among various bacterial species is considered one of the most important mechanisms for the spread of multidrug resistance. To gain insights into the evolution of gene organization and antimicrobial resistance in clinical bacterial samples, a complete plasmid genome of Klebsiella pneumoniae pKF3-140 is determined, which has a circular chromosome of 147,416bp in length. Among the 203 predicted genes, 142 have function assignment and about 50 appear to be involved in plasmid replication, maintenance, conjugative transfer, iron acquisition and transport, and drug resistance. Extensive comparative genomic analyses revealed that pKF3-140 exhibits a rather low sequence similarity and structural conservation with other reported K. pneumoniae plasmids. In contrast, the overall organization of pKF3-140 is highly similar to Escherichia coli plasmids p1ESCUM and pUTI89, which indicates the possibility that K. pneumoniae pKF3-140 may have a potential origin in E. coli. Meanwhile, interestingly, several drug resistant genes show high similarity to the plasmid pU302L in Salmonella enterica serovar Typhimurium U302 strain G8430 and the plasmid pK245 in K. pneumoniae. This mosaic pattern of sequence similarities suggests that pKF3-140 might have arisen from E. coli and acquired the resistance genes from a variety of enteric bacteria and underscores the importance of a further understanding of horizontal gene transfer among enteric bacteria.201323402892
5144170.9958Genomic analysis of the nomenclatural type strain of the nematode-associated entomopathogenic bacterium Providencia vermicola. BACKGROUND: Enterobacteria of the genus Providencia are mainly known as opportunistic human pathogens but have been isolated from highly diverse natural environments. The species Providencia vermicola comprises insect pathogenic bacteria carried by entomoparasitic nematodes and is investigated as a possible insect biocontrol agent. The recent publication of several genome sequences from bacteria assigned to this species has given rise to inconsistent preliminary results. RESULTS: The genome of the nematode-derived P. vermicola type strain DSM_17385 has been assembled into a 4.2 Mb sequence comprising 5 scaffolds and 13 contigs. A total of 3969 protein-encoding genes were identified. Multilocus sequence typing with different marker sets revealed that none of the previously published presumed P. vermicola genomes represents this taxonomic species. Comparative genomic analysis has confirmed a close phylogenetic relationship of P. vermicola to the P. rettgeri species complex. P. vermicola DSM_17385 carries a type III secretion system (T3SS-1) with probable function in host cell invasion or intracellular survival. Potentially antibiotic resistance-associated genes comprising numerous efflux pumps and point-mutated house-keeping genes, have been identified across the P. vermicola genome. A single small (3.7 kb) plasmid identified, pPVER1, structurally belongs to the qnrD-type family of fluoroquinolone resistance conferring plasmids that is prominent in Providencia and Proteus bacteria, but lacks the qnrD resistance gene. CONCLUSIONS: The sequence reported represents the first well-supported published genome for the taxonomic species P. vermicola to be used as reference in further comparative genomics studies on Providencia bacteria. Due to a striking difference in the type of injectisome encoded by the respective genomes, P. vermicola might operate a fundamentally different mechanism of entomopathogenicity when compared to insect-pathogenic Providencia sneebia or Providencia burhodogranariea. The complete absence of antibiotic resistance gene carrying plasmids or mobile genetic elements as those causing multi drug resistance phenomena in clinical Providencia strains, is consistent with the invertebrate pathogen P. vermicola being in its natural environment efficiently excluded from the propagation routes of multidrug resistance (MDR) carrying genetic elements operating between human pathogens. Susceptibility to MDR plasmid acquisition will likely become a major criterion in the evaluation of P. vermicola for potential applications in biological pest control.202134598677
5142180.9957Comparative genomics of Clostridium bolteae and Clostridium clostridioforme reveals species-specific genomic properties and numerous putative antibiotic resistance determinants. BACKGROUND: Clostridium bolteae and Clostridium clostridioforme, previously included in the complex C. clostridioforme in the group Clostridium XIVa, remain difficult to distinguish by phenotypic methods. These bacteria, prevailing in the human intestinal microbiota, are opportunistic pathogens with various drug susceptibility patterns. In order to better characterize the two species and to obtain information on their antibiotic resistance genes, we analyzed the genomes of six strains of C. bolteae and six strains of C. clostridioforme, isolated from human infection. RESULTS: The genome length of C. bolteae varied from 6159 to 6398 kb, and 5719 to 6059 CDSs were detected. The genomes of C. clostridioforme were smaller, between 5467 and 5927 kb, and contained 5231 to 5916 CDSs. The two species display different metabolic pathways. The genomes of C. bolteae contained lactose operons involving PTS system and complex regulation, which contribute to phenotypic differentiation from C. clostridioforme. The Acetyl-CoA pathway, similar to that of Faecalibacterium prausnitzii, a major butyrate producer in the human gut, was only found in C. clostridioforme. The two species have also developed diverse flagella mobility systems contributing to gut colonization. Their genomes harboured many CDSs involved in resistance to beta-lactams, glycopeptides, macrolides, chloramphenicol, lincosamides, rifampin, linezolid, bacitracin, aminoglycosides and tetracyclines. Overall antimicrobial resistance genes were similar within a species, but strain-specific resistance genes were found. We discovered a new group of genes coding for rifampin resistance in C. bolteae. C. bolteae 90B3 was resistant to phenicols and linezolide in producing a 23S rRNA methyltransferase. C. clostridioforme 90A8 contained the VanB-type Tn1549 operon conferring vancomycin resistance. We also detected numerous genes encoding proteins related to efflux pump systems. CONCLUSION: Genomic comparison of C. bolteae and C. clostridiofrome revealed functional differences in butyrate pathways and in flagellar systems, which play a critical role within human microbiota. Most of the resistance genes detected in both species were previously characterized in other bacterial species. A few of them were related to antibiotics inactive against Clostridium spp. Some were part of mobile genetic elements suggesting that these commensals of the human microbiota act as reservoir of antimicrobial resistances.201627769168
8465190.9957Complete Genome Sequence of Weissella cibaria NH9449 and Comprehensive Comparative-Genomic Analysis: Genomic Diversity and Versatility Trait Revealed. Lactic acid bacteria (LAB) in the genus Weissella spp. contain traits in their genome that confer versatility. In particular, Weissella cibaria encodes several beneficial genes that are useful in biotechnological applications. The complete genome of W. cibaria NH9449 was sequenced and an in silico comparative analysis was performed to gain insight into the genomic diversity among members of the genus Weissella. A total of 219 Weissella genomes were used in a bioinformatics analysis of pan-genomes, phylogenetics, self-defense mechanisms, virulence factors, antimicrobial resistance, and carbohydrate-active enzymes. These investigations showed that the strain NH9449 encodes several restriction-modification-related genes and a CRISPR-Cas region in its genome. The identification of carbohydrate-active enzyme-encoding genes indicated that this strain could be beneficial in biotechnological applications. The comparative genomic analysis reveals the very high genomic diversity in this genus, and some marked differences in genetic variation and genes among Weissella species. The calculated average amino acid identity (AAI) and phylogenetic analysis of core and accessory genes shows the possible existence of three new species in this genus. These new genomic insights into Weissella species and their biological functions could be useful in the food industry and other applications.202235663880