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1.
Hum Mutat ; 2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35446444

RESUMO

An autosomal recessive disease is caused by biallelic loss-of-function mutations. However, when more than two disease-causing variants are found in a patient's gene, it is challenging to determine which two of the variants are responsible for the disease phenotype. Here, to decipher the pathogenic variants by precise haplotyping, we applied nanopore Cas9-targeted sequencing (nCATS) to three truncation COL7A1 variants detected in a patient with recessive dystrophic epidermolysis bullosa (EB). The distance between the most 5' and 3' variants was approximately 19 kb at the level of genomic DNA. nCATS successfully demonstrated that the most 5' and 3' variants were located in one allele while the variant in between was located in the other allele. Interestingly, the proband's mother, who was phenotypically intact, was heterozygous for the allele that harbored the two truncation variants, which could otherwise be misinterpreted as those of typical recessive dystrophic EB. Our study highlights the usefulness of nCATS as a tool to determine haplotypes of complicated genetic cases. Haplotyping of multiple variants in a gene can determine which variant should be therapeutically targeted when nucleotide-specific gene therapy is applied.

2.
PLoS One ; 17(3): e0265225, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35312710

RESUMO

5-Methylcytosine is one of the major epigenetic marks of DNA in living organisms. Some bacterial species possess DNA methyltransferases that modify cytosines on both strands to produce fully-methylated sites or on either strand to produce hemi-methylated sites. In this study, we characterized a DNA methyltransferase that produces two sequences with different methylation patterns: one methylated on both strands and another on one strand. M.BatI is the orphan DNA methyltransferase of Bacillus anthracis coded in one of the prophages on the chromosome. Analysis of M.BatI modified DNA by bisulfite sequencing revealed that the enzyme methylates the first cytosine in sequences of 5'-GCAGC-3', 5'-GCTGC-3', and 5'-GCGGC-3', but not of 5'-GCCGC-3'. This resulted in the production of fully-methylated 5'-GCWGC-3' and hemi-methylated 5'-GCSGC-3'. M.BatI also showed toxicity when expressed in E. coli, which was caused by a mechanism other than DNA modification activity. Homologs of M.BatI were found in other Bacillus species on different prophage like regions, suggesting the spread of the gene by several different phages. The discovery of the DNA methyltransferase with unique modification target specificity suggested unrevealed diversity of target sequences of bacterial cytosine DNA methyltransferase.


Assuntos
Citosina , Metiltransferases , DNA/metabolismo , DNA (Citosina-5-)-Metiltransferases/metabolismo , Metilação de DNA , DNA Bacteriano/genética , Escherichia coli/metabolismo , Metiltransferases/metabolismo
3.
Microbiol Resour Announc ; 11(4): e0120321, 2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35289651

RESUMO

Bacillus cereus is mainly associated with foodborne illness but sometimes causes nosocomial infections. We previously reported that B. cereus strains of a specific sequence type, ST1420, were associated with nosocomial infection. Here, we determined the complete genome sequences of B. cereus strains isolated from nosocomial infection cases in Japanese hospitals.

4.
Hum Mutat ; 43(4): 529-536, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35077577

RESUMO

Revertant mosaicism (RM) is a phenomenon in which inherited mutations are spontaneously corrected in somatic cells. RM occurs in some congenital skin diseases, but genetic validation of RM in clinically revertant skin has been challenging, especially when homologous recombination (HR) is responsible for RM. Here, we introduce nanopore Cas9-targeted sequencing (nCATS) for identifying HR in clinically revertant skin. We took advantage of compound heterozygous COL7A1 mutations in a patient with recessive dystrophic epidermolysis bullosa who showed revertant skin spots. Cas9-mediated enrichment of genomic DNA (gDNA) covering the two mutation sites (>8 kb) in COL7A1 and subsequent MinION sequencing successfully detected intragenic crossover in the epidermis of the clinically revertant skin. This method enables the discernment of haplotypes of up to a few tens of kilobases of gDNA. Moreover, it is devoid of polymerase chain reaction amplification, which can technically induce recombination. We, therefore, propose that nCATS is a powerful tool for understanding complicated gene modifications, including RM.


Assuntos
Epidermólise Bolhosa Distrófica , Sistemas CRISPR-Cas , Colágeno Tipo VII/genética , Epidermólise Bolhosa Distrófica/diagnóstico , Epidermólise Bolhosa Distrófica/genética , Humanos , Mosaicismo , Mutação , Pele
5.
Cell Chem Biol ; 29(2): 276-286.e4, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-34990601

RESUMO

ß-Lactam antibiotics disrupt the assembly of peptidoglycan (PG) within the bacterial cell wall by inhibiting the enzymatic activity of penicillin-binding proteins (PBPs). It was recently shown that ß-lactam treatment initializes a futile cycle of PG synthesis and degradation, highlighting major gaps in our understanding of the lethal effects of PBP inhibition by ß-lactam antibiotics. Here, we assess the downstream metabolic consequences of treatment of Escherichia coli with the ß-lactam mecillinam and show that lethality from PBP2 inhibition is a specific consequence of toxic metabolic shifts induced by energy demand from multiple catabolic and anabolic processes, including accelerated protein synthesis downstream of PG futile cycling. Resource allocation into these processes is coincident with alterations in ATP synthesis and utilization, as well as a broadly dysregulated cellular redox environment. These results indicate that the disruption of normal anabolic-catabolic homeostasis by PBP inhibition is an essential factor for ß-lactam antibiotic lethality.


Assuntos
Andinocilina/farmacologia , Antibacterianos/farmacologia , Proteínas de Escherichia coli/antagonistas & inibidores , Escherichia coli/efeitos dos fármacos , Proteínas de Ligação às Penicilinas/antagonistas & inibidores , Andinocilina/química , Antibacterianos/química , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Homeostase/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Proteínas de Ligação às Penicilinas/metabolismo
6.
FEMS Microbiol Lett ; 368(21-24)2022 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-35030252

RESUMO

Multidrug-resistant (MDR) Escherichia coli in food animals such as chickens is an emerging public health concern in Zambia. Additionally, the country's high demand for poultry products necessitates further investigation into the link between poultry and human MDR E. coli. Twenty cefotaxime-resistant E. coli isolates collected from poultry in Lusaka, Zambia, were screened for multidrug resistance and sequenced on MiSeq and MinION platforms. Genomes were assembled de novo and compared with 36 previously reported cefotaxime-resistant E. coli isolates from inpatients at the University Teaching Hospital, Lusaka. All (20/20, 100%) poultry isolates exhibited resistance to ampicillin, chloramphenicol and doxycycline. Phylogenetic analysis and hierarchical clustering showed a high degree of genetic relatedness between E. coli O17:H18-ST69 from poultry and humans. The E. coli O17:H18-ST69 clone accounted for 4/20 (20%) poultry- and 9/36 (25%) human-associated isolates that shared two plasmids harboring 14 antimicrobial resistance (AMR) genes. However, comparison analysis showed that the isolates also had other AMR plasmids distinct for each niche. Our results suggested clonal transmission of MDR E. coli between poultry and humans, with the potential acquisition of niche-specific AMR plasmids. Thus, the control of MDR E. coli requires a One Health approach involving both human and animal health sectors.


Assuntos
Infecções por Escherichia coli , Escherichia coli , Animais , Antibacterianos/farmacologia , Galinhas , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Humanos , Testes de Sensibilidade Microbiana , Filogenia , Aves Domésticas , Zâmbia/epidemiologia
7.
PLoS One ; 16(11): e0260299, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34797889

RESUMO

Anthrax is a worldwide zoonotic disease. Anthrax has long been a public health and socio-economic issue in Mongolia. Presently, there is no spatial information on carcass burial sites as a potential hazard of future anthrax outbreaks and possible risk factors associated with anthrax occurrences in Mongolia. Here, we analyze retrospective data (1986-2015) on the disposal sites of livestock carcasses to describe historical spatio-temporal patterns of livestock anthrax in Khuvsgul Province, which showed the highest anthrax incidence rate in Mongolia. From the results of spatial mean and standard deviational ellipse analyses, we found that the anthrax spatial distribution in livestock did not change over the study period, indicating a localized source of exposure. The multi-distance spatial cluster analysis showed that carcass sites distributed in the study area are clustered. Using kernel density estimation analysis on carcass sites, we identified two anthrax hotspots in low-lying areas around the south and north regions. Notably, this study disclosed a new hotspot in the northern part that emerged in the last decade of the 30-year study period. The highest proportion of cases was recorded in cattle, whose prevalence per area was highest in six districts (i.e., Murun, Chandmani-Undur, Khatgal, Ikh-Uul, Tosontsengel, and Tsagaan-Uul), suggesting that vaccination should prioritize cattle in these districts. Furthermore, size of outbreaks was influenced by the annual summer mean air temperature of Khuvsgul Province, probably by affecting the permafrost freeze-thawing activity.


Assuntos
Antraz/etiologia , Gado/microbiologia , Zoonoses/etiologia , Animais , Bovinos , Surtos de Doenças , Mongólia , Pergelissolo/microbiologia , Saúde Pública/métodos , Estudos Retrospectivos , Fatores de Risco , Estações do Ano , Análise Espacial , Temperatura , Vacinação/métodos
8.
PLoS One ; 16(10): e0258317, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34634075

RESUMO

Anthrax is a zoonotic disease caused by the gram-positive spore-forming bacterium Bacillus anthracis. Detecting naturally acquired antibodies against anthrax sublethal exposure in animals is essential for anthrax surveillance and effective control measures. Serological assays based on protective antigen (PA) of B. anthracis are mainly used for anthrax surveillance and vaccine evaluation. Although the assay is reliable, it is challenging to distinguish the naturally acquired antibodies from vaccine-induced immunity in animals because PA is cross-reactive to both antibodies. Although additional data on the vaccination history of animals could bypass this problem, such data are not readily accessible in many cases. In this study, we established a new enzyme-linked immunosorbent assay (ELISA) specific to antibodies against capsule biosynthesis protein CapA antigen of B. anthracis, which is non-cross-reactive to vaccine-induced antibodies in horses. Using in silico analyses, we screened coding sequences encoded on pXO2 plasmid, which is absent in the veterinary vaccine strain Sterne 34F2 but present in virulent strains of B. anthracis. Among the 8 selected antigen candidates, capsule biosynthesis protein CapA (GBAA_RS28240) and peptide ABC transporter substrate-binding protein (GBAA_RS28340) were detected by antibodies in infected horse sera. Of these, CapA has not yet been identified as immunoreactive in other studies to the best of our knowledge. Considering the protein solubility and specificity of B. anthracis, we prepared the C-terminus region of CapA, named CapA322, and developed CapA322-ELISA based on a horse model. Comparative analysis of the CapA322-ELISA and PAD1-ELISA (ELISA uses domain one of the PA) showed that CapA322-ELISA could detect anti-CapA antibodies in sera from infected horses but was non-reactive to sera from vaccinated horses. The CapA322-ELISA could contribute to the anthrax surveillance in endemic areas, and two immunoreactive proteins identified in this study could be additives to the improvement of current or future vaccine development.


Assuntos
Antraz/imunologia , Anticorpos Antibacterianos/imunologia , Bacillus anthracis/imunologia , Cápsulas Bacterianas/imunologia , Proteínas de Bactérias/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Proteínas de Choque Térmico/imunologia , Animais , Vacinas contra Antraz/imunologia , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/isolamento & purificação , Proteínas de Choque Térmico/isolamento & purificação , Cavalos , Imunoglobulina G/imunologia , Plasmídeos/metabolismo , Homologia de Sequência de Aminoácidos , Esporos Bacterianos/imunologia
9.
Virulence ; 12(1): 2285-2295, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34490836

RESUMO

Bacillus anthracis is an obligate pathogen and a causative agent of anthrax. Its major virulence factors are plasmid-coded; however, recent studies have revealed chromosome-encoded virulence factors, indicating that the current understanding of its virulence mechanism is elusive and needs further investigation. In this study, we established a silkworm (Bombyx mori) infection model of B. anthracis. We showed that silkworms were killed by B. anthracis Sterne and cured of the infection when administered with antibiotics. We quantitatively determined the lethal dose of the bacteria that kills 50% larvae and effective doses of antibiotics that cure 50% infected larvae. Furthermore, we demonstrated that B. anthracis mutants with disruption in virulence genes such as pagA, lef, and atxA had attenuated silkworm-killing ability and reduced colonization in silkworm hemolymph. The silkworm infection model established in this study can be utilized in large-scale infection experiments to identify novel virulence determinants and develop novel therapeutic options against B. anthracis infections.


Assuntos
Antraz , Bombyx , Virulência , Animais , Antibacterianos/farmacologia , Bacillus anthracis/efeitos dos fármacos , Bacillus anthracis/patogenicidade , Modelos Animais de Doenças , Fatores de Virulência/genética
10.
mSystems ; 6(4): e0029121, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34282944

RESUMO

AtxA, the master virulence regulator of Bacillus anthracis, regulates the expression of three toxins and genes for capsule formation that are required for the pathogenicity of B. anthracis. Recent transcriptome analyses showed that AtxA affects a large number of genes on the chromosome and plasmids, suggesting a role as a global regulator. However, information on genes directly regulated by AtxA is scarce. In this work, we conducted genome-wide analyses and cataloged the binding sites of AtxA in vivo and transcription start sites on the B. anthracis genome. By integrating these results, we detected eight genes as direct regulons of AtxA. These consisted of five protein-coding genes, including two of the three toxin genes, and three genes encoding the small RNAs XrrA and XrrB and a newly discovered 95-nucleotide small RNA, XrrC. Transcriptomes from single-knockout mutants of these small RNAs revealed changes in the transcription levels of genes related to the aerobic electron transport chain, heme biosynthesis, and amino acid metabolism, suggesting their function for the control of cell physiology. These results reveal the first layer of the gene regulatory network for the pathogenicity of B. anthracis and provide a data set for the further study of the genomics and genetics of B. anthracis. IMPORTANCE Bacillus anthracis is the Gram-positive bacterial species that causes anthrax. Anthrax is still prevalent in countries mainly in Asia and Africa, where it causes economic damage and remains a public health issue. The mechanism of pathogenicity is mainly explained by the three toxin proteins expressed from the pXO1 plasmid and by proteins involved in capsule formation expressed from the pXO2 plasmid. AtxA is a protein expressed from the pXO1 plasmid that is known to upregulate genes involved in toxin production and capsule formation and is thus considered the master virulence regulator of B. anthracis. Therefore, understanding the detailed mechanism of gene regulation is important for the control of anthrax. The significance of this work lies in the identification of genes that are directly regulated by AtxA via genome-wide analyses. The results reveal the first layer of the gene regulatory network for the pathogenicity of B. anthracis and provide useful resources for a further understanding of B. anthracis.

11.
Antimicrob Resist Infect Control ; 10(1): 79, 2021 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-33971966

RESUMO

BACKGROUND: The epidemiology of extended-spectrum ß-lactamases (ESBLs) has undergone dramatic changes, with CTX-M-type enzymes prevailing over other types. blaCTX-M genes, encoding CTX-M-type ESBLs, are usually found on plasmids, but chromosomal location is becoming common. Given that blaCTX-M-harboring strains often exhibit multidrug resistance (MDR), it is important to investigate the association between chromosomally integrated blaCTX-M and the presence of additional antimicrobial resistance (AMR) genes, and to identify other relevant genetic elements. METHODS: A total of 46 clinical isolates of cefotaxime-resistant Enterobacteriaceae (1 Enterobacter cloacae, 9 Klebsiella pneumoniae, and 36 Escherichia coli) from Zambia were subjected to whole-genome sequencing (WGS) using MiSeq and MinION. By reconstructing nearly complete genomes, blaCTX-M genes were categorized as either chromosomal or plasmid-borne. RESULTS: WGS-based genotyping identified 58 AMR genes, including four blaCTX-M alleles (i.e., blaCTX-M-14, blaCTX-M-15, blaCTX-M-27, and blaCTX-M-55). Hierarchical clustering using selected phenotypic and genotypic characteristics suggested clonal dissemination of blaCTX-M genes. Out of 45 blaCTX-M gene-carrying strains, 7 harbored the gene in their chromosome. In one E. cloacae and three E. coli strains, chromosomal blaCTX-M-15 was located on insertions longer than 10 kb. These insertions were bounded by ISEcp1 at one end, exhibited a high degree of nucleotide sequence homology with previously reported plasmids, and carried multiple AMR genes that corresponded with phenotypic AMR profiles. CONCLUSION: Our study revealed the co-occurrence of ISEcp1-blaCTX-M-15 and multiple AMR genes on chromosomal insertions in E. cloacae and E. coli, suggesting that ISEcp1 may be responsible for the transposition of diverse AMR genes from plasmids to chromosomes. Stable retention of such insertions in chromosomes may facilitate the successful propagation of MDR clones among these Enterobacteriaceae species.


Assuntos
Cromossomos Bacterianos/genética , Farmacorresistência Bacteriana/genética , Enterobacter cloacae , Escherichia coli , beta-Lactamases/genética , Antibacterianos/farmacologia , Enterobacter cloacae/efeitos dos fármacos , Enterobacter cloacae/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Humanos , Testes de Sensibilidade Microbiana , Mutagênese Insercional , Plasmídeos , Sequenciamento Completo do Genoma , Zâmbia
12.
Microbiol Immunol ; 65(3): 115-124, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33368645

RESUMO

We previously isolated a symbiotic environmental amoeba, harboring an environmental chlamydia, Neochlamydia S13. Interestingly, this bacterium failed to survive outside of host cells and was immediately digested inside other amoebae, indicating bacterial distribution via cytokinesis. This may provide a model for understanding organelle development and chlamydial pathogenesis and evolution; therefore, we assessed our hypothesis of Neochlamydia S13 distribution via cytokinesis by comparative analysis with other environmental Chlamydiae (Protochlamydia R18 and Parachlamydia Bn9 ). Dual staining with 4',6-diamidino-2-phenylindole and phalloidin revealed that the progeny of Neochlamydia S13 and Protochlamydia R18 existed in both daughter cells with a contractile ring on the verge of separation. However, in contrast to other environmental Chlamydiae, little Neochlamydia S13 16S ribosomal DNA was amplified from the culture supernatant. Interestingly, Neochlamydia S13 failed to infect aposymbiotic amoebae, indicating an intimate interaction with the host cells. Furthermore, its infectious rates in cultures expanded from a single amoeba were always maintained at 100%, indicating distribution via cytokinesis. We concluded that unlike other environmental Chlamydiae, Neochlamydia S13 has a unique ability to divide its progeny only via host amoebal cytokinesis. This may be a suitable model to elucidate the mechanism of cell organelle distribution and of chlamydial pathogenesis and evolution.


Assuntos
Amoeba , Chlamydiales , Citocinese , Amoeba/microbiologia , RNA Ribossômico 16S/genética , Simbiose
14.
Front Microbiol ; 11: 1628, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32765461

RESUMO

Epigenetic DNA base methylation plays important roles in gene expression regulation. We here describe a gene expression regulation network consisting of many DNA methyltransferases each frequently changing its target sequence-specificity. Our object Helicobacter pylori, a bacterium responsible for most incidence of stomach cancer, carries a large and variable repertoire of sequence-specific DNA methyltransferases. By creating a dozen of single-gene knockout strains for the methyltransferases, we revealed that they form a network controlling methylome, transcriptome and adaptive phenotype sets. The methyltransferases interact with each other in a hierarchical way, sometimes regulated positively by one methyltransferase but negatively with another. Motility, oxidative stress tolerance and DNA damage repair are likewise regulated by multiple methyltransferases. Their regulation sometimes involves translation start and stop codons suggesting coupling of methylation, transcription and translation. The methyltransferases frequently change their sequence-specificity through gene conversion of their target recognition domain and switch their target sets to remodel the network. The emerging picture of a metamorphosing gene regulation network, or firework, consisting of epigenetic systems ever-changing their specificity in search for adaptation, provides a new paradigm in understanding global gene regulation and adaptive evolution.

15.
Microbiome ; 7(1): 119, 2019 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-31455406

RESUMO

BACKGROUND: Elucidating the ecological and biological identity of extrachromosomal mobile genetic elements (eMGEs), such as plasmids and bacteriophages, in the human gut remains challenging due to their high complexity and diversity. RESULTS: Here, we show efficient identification of eMGEs as complete circular or linear contigs from PacBio long-read metagenomic data. De novo assembly of PacBio long reads from 12 faecal samples generated 82 eMGE contigs (2.5~666.7-kb), which were classified as 71 plasmids and 11 bacteriophages, including 58 novel plasmids and six bacteriophages, and complete genomes of five diverse crAssphages with terminal direct repeats. In a dataset of 413 gut metagenomes from five countries, many of the identified plasmids were highly abundant and prevalent. The ratio of gut plasmids by our plasmid data is more than twice that in the public database. Plasmids outnumbered bacterial chromosomes three to one on average in this metagenomic dataset. Host prediction suggested that Bacteroidetes-associated plasmids predominated, regardless of microbial abundance. The analysis found several plasmid-enriched functions, such as inorganic ion transport, while antibiotic resistance genes were harboured mostly in low-abundance Proteobacteria-associated plasmids. CONCLUSIONS: Overall, long-read metagenomics provided an efficient approach for unravelling the complete structure of human gut eMGEs, particularly plasmids.


Assuntos
Bacteriófagos/genética , Fezes/microbiologia , Microbioma Gastrointestinal , Trato Gastrointestinal/microbiologia , Metagenoma/genética , Plasmídeos/genética , Bactérias/genética , Bactérias/isolamento & purificação , Genoma Bacteriano , Humanos , Sequências Repetitivas Dispersas/genética , Japão
16.
PeerJ ; 7: e6718, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30997291

RESUMO

The anthrax toxin is a virulence factor produced by the bacterium Bacillus anthracis. Transcription of anthrax toxin genes is controlled by the transcription factor AtxA. Thus, AtxA is thought to be a key factor for the pathogenicity of B. anthracis. Despite its important role in B. anthracis infection, the molecular mechanism by which AtxA controls expression of anthrax toxin remains unclear. This study aimed to characterize the molecular mechanism of AtxA-mediated regulation of protective antigen (PA), a component of anthrax toxin encoded by the pagA gene. First, the interaction between the upstream region of pagA and AtxA was evaluated in vivo by constructing a transcriptional fusion of the upstream region with an auxotrophic marker. The results showed that (i) the upstream region of pagA suppressed transcription of the downstream gene and (ii) AtxA recovered suppressed transcription. Second, in vitro analysis using a gel mobility shift assay was performed to evaluate binding specificity of the AtxA-DNA interaction. The result showed sequence-independent binding of AtxA to DNA. Taken together, our findings suggest that the expression of PA was suppressed by the upstream region of pagA and that an interaction of AtxA and the upstream region releases the suppression.

17.
Emerg Infect Dis ; 25(5): 883-890, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31002057

RESUMO

Bacillus cereus is associated with foodborne illnesses characterized by vomiting and diarrhea. Although some B. cereus strains that cause severe extraintestinal infections and nosocomial infections are recognized as serious public health threats in healthcare settings, the genetic backgrounds of B. cereus strains causing such infections remain unknown. By conducting pulsed-field gel electrophoresis and multilocus sequence typing, we found that a novel sequence type (ST), newly registered as ST1420, was the dominant ST isolated from the cases of nosocomial infections that occurred in 3 locations in Japan in 2006, 2013, and 2016. Phylogenetic analysis showed that ST1420 strains belonged to the Cereus III lineage, which is much closer to the Anthracis lineage than to other Cereus lineages. Our results suggest that ST1420 is a prevalent ST in B. cereus strains that have caused recent nosocomial infections in Japan.


Assuntos
Bacillus cereus/classificação , Bacillus cereus/genética , Bacteriemia , Infecção Hospitalar/microbiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Alelos , Infecção Hospitalar/epidemiologia , DNA Bacteriano , Genes Bacterianos , Genótipo , Infecções por Bactérias Gram-Positivas/epidemiologia , Humanos , Japão/epidemiologia , Tipagem Molecular , Filogenia
18.
J Med Microbiol ; 68(4): 633-641, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30806617

RESUMO

PURPOSE: Intra-familial infection, mother-to-child infection, is considered to be one of the main routes of transmission for Helicobacter pylori, in developed countries such as Japan. A major role for intra-familial spread in the pathogenicity of H. pylori is now beyond controversy, although the major route of transmission remains poorly understood. We performed this study to clarify the factors determining intra-familial transmission. METHODOLOGY: We used several H. pylori strains isolated from family members to compare infectivity. H. pylori K21 and K22 strains were isolated from the father and mother, and the K25 strain was isolated from the third child of the family. Mongolian gerbils were inoculated with H. pylori strains and the infectivity of three strains was compared in each experiment. In addition, the whole genome sequence, adhesion to gastric epithelial cells and the growth of static condition or continuous flow culture among three strains of H. pylori were analysed.Results/Key findings. Most of the colonies were determined as the same molecular type K25 in all of the four grouped animals and H. pylori K25 was observed as the dominant strain. The stronger adhesion capacity of the K25 strain was observed in comparison with the other two strains through in vitro analysis. By assessing the genomic profiles of H. pylori isolates from three strains, identified TnPZ regions were detected only in the K25 strain. CONCLUSION: The infectivity of H. pylori isolates intra-familial infection and animal infection were prescribed by the adhesion capacity and molecular type of each strain.


Assuntos
Aderência Bacteriana , Infecções por Helicobacter/microbiologia , Helicobacter pylori/isolamento & purificação , Transmissão Vertical de Doenças Infecciosas , Animais , Criança , Modelos Animais de Doenças , Células Epiteliais/microbiologia , Família , Feminino , Mucosa Gástrica/microbiologia , Genoma Bacteriano , Gerbillinae/microbiologia , Helicobacter pylori/patogenicidade , Humanos , Masculino , Estômago/microbiologia , Sequenciamento Completo do Genoma
20.
mSystems ; 3(5)2018.
Artigo em Inglês | MEDLINE | ID: mdl-30417107

RESUMO

Bacillus anthracis is a Gram-positive endospore-forming bacterial species that causes anthrax in both humans and animals. In Zambia, anthrax cases are frequently reported in both livestock and wildlife, with occasional transmission to humans, causing serious public health problems in the country. To understand the genetic diversity of B. anthracis strains in Zambia, we sequenced and compared the genomic DNA of B. anthracis strains isolated across the country. Single nucleotide polymorphisms clustered these strains into three groups. Genome sequence comparisons revealed a large deletion in strains belonging to one of the groups, possibly due to unequal crossing over between a pair of rRNA operons. The deleted genomic region included genes conferring resistance to bacitracin, and the strains with the deletion were confirmed with loss of bacitracin resistance. Similar deletions between rRNA operons were also observed in a few B. anthracis strains phylogenetically distant from Zambian strains. The structure of bacitracin resistance genes flanked by rRNA operons was conserved only in members of the Bacillus cereus group. The diversity and genomic characteristics of B. anthracis strains determined in this study would help in the development of genetic markers and treatment of anthrax in Zambia. IMPORTANCE Anthrax is caused by Bacillus anthracis, an endospore-forming soil bacterium. The genetic diversity of B. anthracis is known to be low compared with that of Bacillus species. In this study, we performed whole-genome sequencing of Zambian isolates of B. anthracis to understand the genetic diversity between closely related strains. Comparison of genomic sequences revealed that closely related strains were separated into three groups based on single nucleotide polymorphisms distributed throughout the genome. A large genomic deletion was detected in the region containing a bacitracin resistance gene cluster flanked by rRNA operons, resulting in the loss of bacitracin resistance. The structure of the deleted region, which was also conserved among species of the Bacillus cereus group, has the potential for both deletion and amplification and thus might be enabling the species to flexibly control the level of bacitracin resistance for adaptive evolution.

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