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1.
Arch Virol ; 169(7): 134, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38834736

RESUMO

Anthrax is an acute infectious zoonotic disease caused by Bacillus anthracis, a bacterium that is considered a potential biological warfare agent. Bacillus bacteriophages shape the composition and evolution of bacterial communities in nature and therefore have important roles in the ecosystem community. B. anthracis phages are not only used in etiological diagnostics but also have promising prospects in clinical therapeutics or for disinfection in anthrax outbreaks. In this study, two temperate B. anthracis phages, vB_BanS_A16R1 (A16R1) and vB_BanS_A16R4 (A16R4), were isolated and showed siphovirus-like morphological characteristics. Genome sequencing showed that the genomes of phages A16R1 and A16R4 are 36,569 bp and 40,059 bp in length, respectively. A16R1 belongs to the genus Wbetavirus, while A16R4 belongs to the genus Hubeivirus and is the first phage of that genus found to lyse B. anthracis. Because these two phages can comparatively specifically lyse B. anthracis, they could be used as alternative diagnostic tools for identification of B. anthracis infections.


Assuntos
Fagos Bacilares , Bacillus anthracis , Genoma Viral , Bacillus anthracis/virologia , Genoma Viral/genética , Fagos Bacilares/isolamento & purificação , Fagos Bacilares/genética , Fagos Bacilares/classificação , Siphoviridae/genética , Siphoviridae/isolamento & purificação , Siphoviridae/classificação , Filogenia
2.
Inorg Chem ; 60(13): 9869-9879, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34121406

RESUMO

Two Wells-Dawson arsenotungstate coordination polymers, [{CuII(bim)2}3(As2W18O62)] (1) and [(CuI10pz10Cl4)(As2W18O62)] (bim = 2,2'-biimidazole; pz = pyrazine), have been assembled via a hydrothermal method and fully characterized. Compound 1 exhibits a 2,6-connected two-dimensional hybrid layer based on asymmetrically modified {As2W18} anions and {Cu(bim)2} linkers, which is extended to a three-dimensional network with a special interlayer structure and a one-dimensional tunnel. Compound 2 is a host-guest framework that consists of a Cu-pz-Cl network with 20-member square rings, 16-member irregular rings, and embedded eight-node {As2W18} guest molecules. Compounds 1 and 2 show uncommon specific capacitance (834.8 and 960.1 F g-1, respectively, at a current density of 2.4 A g-1), enduring cycling stability (capacitance retention rates of 89.3% and 91.9%, respectively, after 5000 cycles), and good electrical conductivity, which are superior to those of the unmodified zero-dimensional Dawson arsenotungstate compound and most reported electrode materials in terms of their stable structure, special layer spacing, and orderly channels. Moreover, the title compounds exhibit excellent electrocatalytic activity for oxidizing ascorbic acid and reducing nitrite.

3.
J Clin Microbiol ; 59(1)2020 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-33115846

RESUMO

The objective of this study was to construct a rapid, high-throughput, and biosafety-compatible screening method for Bacillus anthracis and Bacillus cereus based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). MALDI-TOF MS coupled to ClinProTools was used to discover MALDI-TOF MS biomarker peaks and generate a classification model based on a genetic algorithm (GA) to differentiate between different Bacillus anthracis and Bacillus cereus isolates. Thirty Bacillus anthracis and 19 Bacillus cereus strains were used to construct and analyze the model, and 40 Bacillus strains were used for validation. For the GA screening model, the cross-validation values, which reflect the ability of the model to handle variability among the test spectra, and the recognition capability values, which reflect the model's ability to correctly identify its component spectra, were all 100%. This model contained 10 biomarker peaks (m/z 3,339.9, 3,396.3, 3,682.4, 5,476.7, 6,610.6, 6,680.1, 7,365.3, 7,792.4, 9,475.8, and 10,934.1) used to correctly identify 28 Bacillus anthracis and 12 Bacillus cereus isolates from 40 Bacillus isolates, with a sensitivity and specificity of 100%. With the obvious advantages of being rapid, highly accurate, and highly sensitive and having a low cost and high throughput, MALDI-TOF MS ClinProTools is a powerful and reliable tool for screening Bacillus anthracis and Bacillus cereus strains.


Assuntos
Bacillus anthracis , Bacillus , Bacillus cereus , Humanos , Peptídeos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
4.
BMC Infect Dis ; 20(1): 140, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32059712

RESUMO

BACKGROUND: Anthrax is an endemic disease that persists in the rural regions of China. The global genetic population structure of B.anthracis has also been defined by the canonical single-nucleotide polymorphisms (canSNP) and multiple-locus variable-number tandem repeat analysis (MLVA). Five canSNP lineages were found in China, and the A.Br.Ames lineage has been the second predominant group in recent years in China. The objective of this study was to reveal genetic diversity of the Ames lineage strains by MLVA. METHODS: Two molecular typing methods, canSNP and MLVA with 15markers were used to study the genetic relationship among the Ames lineage strains. The outbreak information associated with these strains was also collected and investigated. RESULTS: From 2007 to 2018, a total of 21 human anthrax infection outbreaks (68 patients) associated with B. anthracis Ames lineage strains were reported in China. Ames lineage strain-associated human anthrax is mainly distributed in the northern part of China, including the provinces of Inner Mongolia, Liaoning, Gansu, and Xinjiang. In the study, a total of 30 Ames lineage strains were included and 10 MLVA15 genotypes were identified. These strains were mainly found in northeast China, Inner Mongolia and Liaoning. In recent years, the Ames lineage strains were isolated in the two provinces every year. The 18 Ames lineage strains isolated from Inner Mongolia were divided into eight MLVA15 genotypes. From 2010 to 2015, there were continuous reports of outbreaks in Keyouzhongqi County, Inner Mongolia, and the strains that were isolated annually in succession belonged to the MLVA15-30 genotype. CONCLUSIONS: The Ames lineage strains are widely distributed in northern China. Their genetic diversity can be illustrated by the results of the MLVA. The genetic characteristics of the Ames lineage strains from outbreaks in different provinces varied. In some areas, human anthrax outbreaks occurred annually in succession, and these related strains grouped together. These observations indicate that the local environment was persistently contaminated with B. anthracis spores, vaccination of livestock should become the fundamental control measure in the areas.


Assuntos
Antraz/microbiologia , Bacillus anthracis/genética , Variação Genética , Animais , Antraz/epidemiologia , Bacillus anthracis/isolamento & purificação , China/epidemiologia , Surtos de Doenças , Genética Populacional , Genótipo , Humanos , Gado/microbiologia , Repetições Minissatélites , Tipagem Molecular , Polimorfismo de Nucleotídeo Único
6.
China CDC Wkly ; 4(35): 783-787, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36284605

RESUMO

Introduction: The epidemic of human anthrax is at a low level in China in recent years, but the reported incidence increased in 2021. In order to understand the current landscape of research and knowledge about anthrax in China, the epidemiological characteristics of anthrax in humans from 2018 to 2021 were analyzed and the prevention and control suggestions were proposed. Methods: Surveillance data of anthrax in humans and livestock, together with human outbreaks data during 2018-2021, were collected and analyzed by descriptive statistics methods. The number and proportion of outbreaks, cases and deaths by provincial-level administrative divisions (PLADs), clinical types, and contributing factors were calculated. Results: A total of 1,244 cases of human anthrax and 53 outbreaks were reported from 2018 to 2021 in China. While the incidence of anthrax declined from 2018 to 2020, it increased in 2021. The regions of anthrax were mainly located in the west and the northeast PLADs of China, though cases were reported in some central and eastern PLADs in 2021. Young and middle-aged men involved in animal husbandry were found to be at a higher risk of anthrax. All the reported outbreaks were associated with the exposure of infected livestock. A total of 296 livestock anthrax cases were reported. Conclusions: The increased incidence and wider geographical distribution of human anthrax in 2021 were found to be the result of inadequate supervision of diseased animals as well as updated diagnostic criteria. As such, the monitoring of risk factors and emergency preparation procedures should be strengthened at the national level. In addition, it is also critical to strengthen health education for high-risk occupational groups and strengthen professional training for local clinicians. Finally, more measures should be carried out to strengthen anthrax surveillance in livestock husbandry.

7.
China CDC Wkly ; 4(49): 1093-1096, 2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36751663

RESUMO

What is already known about this topic?: Antibiotic resistance (AR) is a serious public health threat worldwide. However, the AR and antibiotic resistance genes (ARGs) data from West Africa, especially from Sierra Leone, are limited. What is added by this report?: The study revealed ARGs' common dissemination, and multiplex antibiotic resistance genes in one sample. Genes bla NDM and bla OXA -48-like were first discovered in Sierra Leone. What are the implications for public health practice?: Basic information is provided for AR research and surveillance and highlights that effective AR surveillance among diarrhea patients is necessary for Sierra Leone and West Africa.

8.
PLoS Negl Trop Dis ; 15(8): e0009558, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34343197

RESUMO

On 12 November 2019, one couple from the Sonid Left Qi (County) in the Inner Mongolia Autonomous Region was diagnosed with pneumonic plague in Beijing. The wife acquired the infection from her husband. Thereafter, two bubonic plague cases were identified in Inner Mongolia on November 16th and 24th. In this study, genome-wide single nucleotide polymorphism (SNP) analysis was used to identify the phylogenetic relationship of Yersinia pestis strains isolated in Inner Mongolia. Strains isolated from reservoirs in 2018 and 2019 in Inner Mongolia, together with the strain isolated from Patient C, were further clustered into 2.MED3m, and two novel lineages (2.MED3q, 2.MED3r) in the 2.MED3 population. According to the analysis of PCR-based molecular subtyping methods, such as the MLVA 14 scheme and seven SNP allele sequencing, Patients A/B and D were classified as 2.MED3m. In addition, strains from rodents living near the patients' residences were clustered into the same lineage as patients. Such observations indicated that human plague cases originated from local reservoirs. Corresponding phylogenetic analysis also indicated that rodent plague strains in different areas in Inner Mongolia belong to different epizootics rather than being caused by spreading from the same epizootic in Meriones unguiculatus in 2019.


Assuntos
Peste/epidemiologia , Yersinia pestis/genética , Yersinia pestis/patogenicidade , Adulto , Animais , Pequim/epidemiologia , China/epidemiologia , Evolução Fatal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , Peste/etiologia , Roedores/microbiologia , Yersinia pestis/isolamento & purificação
9.
J Bacteriol ; 192(13): 3551-2, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20453098

RESUMO

Yersinia pestis, the causative agent of plague, is a deadly bacterium that affects humans. Strain D106004 was isolated from a new plague focus in Yulong County, China, in 2006. To gain insights into the epidemic origin, we have sequenced the genomes of D106004 and strains Z176003 and D182038, isolated from neighboring regions.


Assuntos
Genoma Bacteriano/genética , Yersinia pestis/genética , China , Dados de Sequência Molecular
10.
J Clin Microbiol ; 48(5): 1619-23, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20200297

RESUMO

Yersinia pestis has caused three worldwide plagues in human history that have led to innumerable deaths. We have completely sequenced the genomes of two strains (D106004 and D182038) of Y. pestis isolated from Yunnan Province of China. The most striking finding of our study is that large amounts of genome rearrangement events exist between the genomes of two Yunnan strains despite being isolated from two foci only 50 kilometers apart. When we compared the genome sequences of the Yunnan strains with six strains (CO92, KIM, 91001, Antiqua, Nepal516, and Pestoides F) of Y. pestis sequenced previously, we found that the genomes of Y. pestis were divided into 61 relatively independent segments. Pairwise comparisons of all 61 segments among eight strains showed that the Yunnan strains were most closely related to strain CO92. We concluded that Y. pestis genomes consist of segments that can change their positions and directions within the genomes caused by genome rearrangements, and our study confirmed the inference that the third plague pandemic originated in Yunnan since the genome sequences of Yunnan strains were closest to the strain CO92 isolated from the United States.


Assuntos
Rearranjo Gênico , Genoma Bacteriano , Yersinia pestis/genética , China , Humanos , Análise de Sequência de DNA , Sintenia , Yersinia pestis/isolamento & purificação
11.
BMC Microbiol ; 9: 205, 2009 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-19775435

RESUMO

BACKGROUND: Yersinia pestis, the aetiological agent of plague, has been well defined genotypically on local and worldwide scales. In November 2005, five cases of severe pneumonia of unknown causes, resulting in two deaths, were reported in Yulong, Yunnan province. In this study, we compared Y. pestis isolated from the Yulong focus to strains from other areas. RESULTS: Two hundred and thirteen Y. pestis strains collected from different plague foci in China and a live attenuated vaccine strain of Y. pestis (EV76) were genotyped using multiple-locus variable-number tandem repeat analysis (MLVA) on 14 loci. A total of 214 Y. pestis strains were divided into 85 MLVA types, and Nei's genetic diversity indices of the various loci ranged between 0.02 - 0.76. Minimum spanning tree analysis showed that Y. pestis in China could be divided into six complexes. It was observed that Microtus strains were different from the other three biovar strains. Each plague focus had its own unique MLVA types. CONCLUSION: The strains isolated from Yulong, Yunnan province had a unique MLVA type, indicating a new clone group. Our results suggest that Yulong strains may have a close relationship with strains from the Qinghai-Tibet Plateau plague focus.


Assuntos
Variação Genética , Peste/microbiologia , Yersinia pestis/genética , Técnicas de Tipagem Bacteriana , China , Análise por Conglomerados , DNA Bacteriano/genética , Evolução Molecular , Genótipo , Geografia , Repetições Minissatélites , Filogenia , Polimorfismo Genético , Análise de Sequência de DNA , Yersinia pestis/classificação , Yersinia pestis/isolamento & purificação
12.
PLoS Negl Trop Dis ; 13(6): e0007513, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31233503

RESUMO

BACKGROUND: Leptospirosis is one of the most important neglected tropical bacterial diseases worldwide. However, there is limited information on the genetic diversity and host selectivity of pathogenic Leptospira in wild small mammal populations. METHODOLOGY/PRINCIPAL FINDINGS: Jiangxi Province, located in southern China, is a region highly endemic for leptospirosis. In this study, among a total of 3,531 trapped rodents dominated by Apodemus agrarius (59.7%), 330 Leptospira strains were successfully isolated from six different sites in Jiangxi between 2002 and 2015. Adding 71 local strains from humans, various kinds of livestock and wild animals in Jiangxi, a total of 401 epidemic strains were characterized using 16S rRNA gene senquencing, multilocus sequence typing (MLST) and the microscopic agglutination test (MAT). Among them, the most prevalent serogroup was Icterohaemorrhagiae (61.10%), followed by Javanica (19.20%) and Australis (9.73%); the remaining five serogroups, Canicola, Autumnalis, Grippotyphosa, Hebdomadis and Pomona, accounted for 9.97%. Species identification revealed that 325 were L. interrogans and 76 were L. borgpetersenii. Moreover, L. interrogans was the only pathogenic species in Fuliang and Shanggao and was predominant in Shangrao (95.0%); L. borgpetersenii was the most common in the remaining three sites. Twenty-one sequence types (STs) were identified. Similarly, ST1 and serogroup Icterohaemorrhagiae were most prevalent in Shangrao (86.0% and 86.4%) and Fuliang (90.4% and 90.4%), ST143 and serogroup Javanica in Shangyou (88.5% and 90.4%) and Longnan (73.1% and 73.1%), and ST105 and serogroup Australis in Shanggao (46.3% and 56.1%). Serogroup Icterohaemorhagiae primarily linked to A. agrarius (86.9%), serogroup Canicola to dogs (83.3%). There were significant differences in the distribution of leptospiral species/serogroups/STs prevalence across host species/collected locations among the 394 animal-associated strains (Fisher's exact test, p<0.001). CONCLUSIONS/SIGNIFICANCE: Our study demonstrated high genetic diversity of pathogenic Leptospira strains from wild small animals in Jiangxi from 2002 to 2015. A. agrarius was the most abundantly trapped animal reservoir, and serogroup Icterohaemorrhagiae and ST1 were the most dominant in Jiangxi. Significant geographic variation and host diversity in the distribution of dominant species, STs and serogroups were observed. Moreover, rat-to-human transmission might play a crucial role in the circulation of Leptospirosis in Jiangxi. Details of the serological and molecular characteristics circulating in this region will be essential in implementing prevention and intervention measures to reduce the risk of disease transmission in China. However, phylogenetic analysis of more Leptospira isolates should explore the impact of ecological change on leptospirosis transmission dynamics and investigate how such new knowledge might better impact environmental monitoring for disease control and prevention at a public health level.


Assuntos
Variação Genética , Leptospira/classificação , Leptospira/genética , Leptospirose/epidemiologia , Leptospirose/veterinária , Sorogrupo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Testes de Aglutinação , Animais , Animais Domésticos , Animais Selvagens , Criança , Pré-Escolar , China/epidemiologia , Feminino , Genótipo , Humanos , Lactente , Recém-Nascido , Leptospira/isolamento & purificação , Leptospirose/microbiologia , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Adulto Jovem
13.
PLoS Negl Trop Dis ; 12(11): e0006908, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30418972

RESUMO

Anthrax is a global re-emerging zoonotic disease and is an endemic disease in China, especially in rural regions. In this study, the general characteristics of human anthrax outbreaks that occurred in areas of northwestern China over the past decade have been described. Meanwhile, the genetic characteristics of Bacillus anthracis isolated from these areas from 1990 to 2016 were analyzed by means of canonical single-nucleotide polymorphism (canSNP) analysis and multilocus variable-number tandem repeat analysis (MLVA) with 15 markers. Five sublineages/subgroups, namely, A.Br.001/002, A.Br.Vollum, A.Br.Aust94, A.Br.Ames and A.Br.008/009, were detected by using 13 canSNP sites. All of the sublineages were found in Xinjiang province, while one sublineage was found in Shaanxi, two in Gansu, three in Qinghai and four in Inner Mongolia. However, the geographical distribution of the B. anthracis populations exhibited different canSNP characteristics from those of the strains isolated before 1990 in China. In contrast to previous data, the A.Br.Ames subgroup was also observed to be scattered from Inner Mongolia to other provinces. All 106 strains were assigned to 36 MLVA15 genotypes, and 21 of these types were first observed in this study. The strains collected from anthrax outbreaks in recent decade were classified as subgroups A.Br.001/002 and A.Br.Ames and identified as genotypes MLVA15-28, MLVA15-30, MLVA15-31, MLVA15-38, MLVA15-CHN3, and MLVA15-CHN18. By canSNP analysis and MLVA, we found that the diversification of MLVA genotypes and the geographical distribution of B. anthracis populations is gradually becoming balanced across northwestern China. This study also provides preliminary survey results regarding the population diversity of B. anthracis in China, which will help promote the prevention and control of this important disease.


Assuntos
Antraz/epidemiologia , Bacillus anthracis/genética , Bacillus anthracis/isolamento & purificação , Animais , Antraz/microbiologia , Antraz/prevenção & controle , Antraz/transmissão , Bacillus anthracis/classificação , Bovinos , China/epidemiologia , Surtos de Doenças , Equidae , Variação Genética , Genótipo , Humanos , Gado , Repetições Minissatélites , Mongólia/epidemiologia , Tipagem de Sequências Multilocus , Polimorfismo de Nucleotídeo Único/genética , Análise de Sequência de DNA , Ovinos , Zoonoses/epidemiologia , Zoonoses/prevenção & controle , Zoonoses/transmissão
14.
PLoS One ; 13(8): e0203267, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30161194

RESUMO

Anthrax is an endemic disease in China. Cases are reported every year, especially in the northwestern areas. In August 2016, an outbreak of 21 cutaneous anthrax cases was reported in Min County, Gansu Province, China. In this study, the general characteristics of the anthrax outbreak are described. Two molecular typing methods, canonical single-nucleotide polymorphism (canSNP) and multiple-locus variable-number tandem repeat analysis with 15 markers (MLVA15), were used to investigate the possible source of transmission and to identify the genetic relationship among the strains/samples isolated in this outbreak as well as previous isolates. In this outbreak, all patients were infected through contact with diseased livestock or contaminated animal products. Livestock had been introduced into the local area shortly before the outbreak from Gannan Prefecture (in Gansu Province), Sichuan and Qinghai Provinces. In the molecular typing analysis, there were two canSNP subgroups found in Gansu, A.Br.001/002 and A.Br.Ames, and five MLVA15 genotypes were observed. The strains collected from the anthrax outbreak in Min County in 2016 belonged to the A.Br.001/002 canSNP subgroup and the MLVA15-28 and MLVA15-30 genotype. Strains previously isolated from Sichuan, Inner Mongolia and Maqu County (in Gannan Prefecture, Gansu Province) were clustered with these outbreak-related strains/samples according to the MLVA15-30 genotype. The MLVA15-28 genotype was found in strains isolated from Gansu and Xinjiang in previous studies. Combining the epidemiological investigation and molecular typing results, we conclude that the patients in this outbreak were infected by a local pathogen present in the adjoining area of Gansu, Sichuan and Qinghai Provinces.


Assuntos
Antraz/epidemiologia , Adolescente , Adulto , Idoso , Animais , Antraz/genética , Bacillus anthracis/genética , Criança , China/epidemiologia , Surtos de Doenças , Feminino , Humanos , Gado , Masculino , Pessoa de Meia-Idade , Repetições Minissatélites , Epidemiologia Molecular , Tipagem Molecular , Polimorfismo de Nucleotídeo Único , Adulto Jovem
15.
Artigo em Inglês | MEDLINE | ID: mdl-28702375

RESUMO

Anthrax toxins and capsules, which are encoded by genes located on pXO1 and pXO2, respectively, are major virulence factors of Bacillus anthracis. Our previous studies demonstrated that exposure to high-temperatures is unable to abolish the pXO1 plasmid of the Pasteur II strain, but the growth of the strain was obviously slower than that of the Sterne strain and wild-type virulent strain. To elucidate a potential regulatory mechanism of slowing growth, we employed comparative genome and bioinformatic analysis and revealed a unique SNP (G to T) at the 143135 bp position in pXO1 that is possibly involved in the mediation of growth of Pasteur II. However, the T to G mutation in groR did not result in any change of the amino acid sequence. A predominant nucleotide G existed at the 143135 bp in pXO1 of 100 wild-type B. anthracis isolates and 9 isolates documented in GenBank, whereas T replaced G in pXO1 of the Pasteur II strain. Further analysis indicate that the SNP is located in a gene between 143042 and 143173 bp, and that it encodes a small protein of 43 amino acids and is termed as a growth regulator (GroR). Site-directed mutagenesis and gene deletion demonstrates that groR regulates the growth and spore formation of B. anthracis. Our results indicate that the pXO1 plasmid is involved in the regulation of growth and spore formation in B. anthracis.


Assuntos
Bacillus anthracis/genética , Polimorfismo de Nucleotídeo Único , Esporos Bacterianos/crescimento & desenvolvimento , Antígenos de Bactérias/genética , Antígenos de Bactérias/metabolismo , Antígenos de Bactérias/toxicidade , Bacillus anthracis/crescimento & desenvolvimento , Bacillus anthracis/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Toxinas Bacterianas/toxicidade , Plasmídeos/genética , Plasmídeos/metabolismo , Esporos Bacterianos/genética , Esporos Bacterianos/metabolismo
16.
Infect Dis Poverty ; 6(1): 14, 2017 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-28093076

RESUMO

BACKGROUND: Anthrax is an acute zoonotic infectious disease caused by the bacterium known as Bacillus anthracis. From 26 July to 8 August 2015, an outbreak with 20 suspected cutaneous anthrax cases was reported in Ganquan County, Shaanxi province in China. The genetic source tracking analysis of the anthrax outbreak was performed by molecular epidemiological methods in this study. METHODS: Three molecular typing methods, namely canonical single nucleotide polymorphisms (canSNP), multiple-locus variable-number tandem repeat analysis (MLVA), and single nucleotide repeat (SNR) analysis, were used to investigate the possible source of transmission and identify the genetic relationship among the strains isolated from human cases and diseased animals during the outbreak. RESULTS: Five strains isolated from diseased mules were clustered together with patients' isolates using canSNP typing and MLVA. The causative B. anthracis lineages in this outbreak belonged to the A.Br.001/002 canSNP subgroup and the MLVA15-31 genotype (the 31 genotype in MLVA15 scheme). Because nine isolates from another four provinces in China were clustered together with outbreak-related strains by the canSNP (A.Br.001/002 subgroup) and MLVA15 method (MLVA15-31 genotype), still another SNR analysis (CL10, CL12, CL33, and CL35) was used to source track the outbreak, and the results suggesting that these patients in the anthrax outbreak were probably infected by the same pathogen clone. CONCLUSIONS: It was deduced that the anthrax outbreak occurred in Shaanxi province, China in 2015 was a local occurrence.


Assuntos
Antraz/epidemiologia , Antraz/microbiologia , Bacillus anthracis/genética , Surtos de Doenças , Dermatopatias Bacterianas/epidemiologia , Dermatopatias Bacterianas/microbiologia , Animais , Antraz/transmissão , China/epidemiologia , Feminino , Genótipo , Humanos , Masculino , Análise de Sequência de DNA , Dermatopatias Bacterianas/transmissão , Zoonoses/epidemiologia , Zoonoses/microbiologia , Zoonoses/transmissão
17.
Virulence ; 7(5): 578-86, 2016 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-27029580

RESUMO

Anthrax toxins and capsule are the major virulence factors of Bacillus anthracis. They are encoded by genes located on the plasmids pXO1 and pXO2, respectively. The vaccine strain Pasteur II was produced from high temperature subcultures of B. anthracis, which resulted in virulence attenuation through the loss of the plasmid pXO1. However, it is unclear whether the high temperature culture completely abolishes the plasmid DNA or affects the replication of the plasmid pXO1. In this study, we tested 3 B. anthracis vaccine strains, including Pasteur II from France, Qiankefusiji II from Russia, and Rentian II from Japan, which were all generated from subcultures at high temperatures. Surprisingly, we detected the presence of pXO1 plasmid DNA using overlap PCR in all these vaccine strains. DNA sequencing analysis of overlap PCR products further confirmed the presence of pXO1. Moreover, the expression of the protective antigen (PA) encoded on pXO1 was determined by using SDS-PAGE and western blotting. In addition, we mimicked Pasteur's method and exposed the A16R vaccine strain, which lacks the pXO2 plasmid, to high temperature, and identified the pXO1 plasmid in the subcultures at high temperatures. This indicated that the high temperature treatment at 42.5°C was unable to eliminate pXO1 plasmid DNA from B. anthracis. Our results suggest that the attenuation of the Pasteur II vaccine strain is likely due to the impact of high temperature stress on plasmid replication, which in turn limits the copy number of pXO1. Our data provide new insights into the mechanisms of the remaining immunogenicity and toxicity of the vaccine strains.


Assuntos
Vacinas contra Antraz/genética , Bacillus anthracis/genética , Plasmídeos , Vacinas Atenuadas/genética , Vacinas contra Antraz/imunologia , Antígenos de Bactérias/genética , Bacillus anthracis/imunologia , Bacillus anthracis/patogenicidade , Toxinas Bacterianas/genética , DNA Bacteriano/análise , Temperatura Alta , Imunogenicidade da Vacina , Plasmídeos/genética , Plasmídeos/isolamento & purificação , Reação em Cadeia da Polimerase , Vacinas Atenuadas/imunologia , Virulência , Fatores de Virulência
18.
Sci Rep ; 6: 28827, 2016 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-27363681

RESUMO

Anthrax is a disease caused by Bacillus anthracis. Specifically, the anthrax toxins and capsules encoded by the pXO1 and pXO2 plasmids, respectively, are the major virulence factors. We previously reported that the pXO1 plasmid was retained in the attenuated strain of B. anthracis vaccine strains even after subculturing at high temperatures. In the present study, we reinvestigate the attenuation mechanism of Pasteur II. Sequencing of pXO1 and pXO2 from Pasteur II strain revealed mutations in these plasmids as compared to the reference sequences. Two deletions on these plasmids, one each on pXO1 and pXO2, were confirmed to be unique to the Pasteur II strain as compared to the wild-type strains. Gene replacement with homologous recombination revealed that the mutation in the promoter region of the pagR gene on pXO2, but not the mutation on pXO1, contributes to lethal levels of toxin production. This result was further confirmed by RT-PCR, western blot, and animal toxicity assays. Taken together, our results signify that the attenuation of the Pasteur II vaccine strain is caused by a mutation in the pagR gene on its pXO2 plasmid. Moreover, these data suggest that pXO2 plasmid encoded proteins are involved in the virulence of B. anthracis.


Assuntos
Bacillus anthracis/genética , Proteínas de Bactérias/genética , Plasmídeos/genética , Proteínas Repressoras/genética , Animais , Antraz/virologia , Antígenos de Bactérias/genética , Antígenos de Bactérias/metabolismo , Bacillus anthracis/metabolismo , Bacillus anthracis/patogenicidade , Proteínas de Bactérias/classificação , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Sequência de Bases , DNA Bacteriano/química , DNA Bacteriano/genética , Masculino , Camundongos Endogâmicos BALB C , Mutação , Plasmídeos/metabolismo , Regiões Promotoras Genéticas/genética , Proteínas Repressoras/classificação , Proteínas Repressoras/metabolismo , Análise de Sequência de DNA , Análise de Sobrevida , Virulência/genética
20.
PLoS One ; 11(6): e0157496, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27299730

RESUMO

Anthrax is a continuous threat in China, especially in rural regions. In July 2015, an anthrax outbreak occurred in Xifeng County, Liaoning Province. A total of 10 cutaneous anthrax cases were reported, with 210 people under medical observation. In this study, the general characteristics of human anthrax outbreak occurred in Liaoning Province were described, and all cases were caused by butchering and contacting sick animal. Meanwhile, the phylogenetic relationship between outbreak-related isolates/samples of the year 2015 and previous Bacillus anthracis strains was analyzed by means of canonical single nucleotide polymorphisms (canSNP), multiple-locus variable-number tandem repeat analysis (MLVA) with 15 markers and single-nucleotide repeats (SNR) analysis. There are two canSNP subgroups found in Liaoning, A.Br.001/002 and A.Br.Ames, and a total of six MLVA 15 genotypes and five SNR genotypes were observed. The strain collected from anthrax outbreak in Xifeng County in 2015 was classified as A.Br.001/002 subgroup and identified as MLVA15-29 genotype, with same SNR profile (CL10: 17, CL12: 15, CL33: 29, and CL35: 13). So we conclude that the same clone of B.anthracis caused the anthrax outbreak in Xifeng County in 2015, and this clone is different to previous isolates. Strengthening public health education in China is one of the most important measures to prevent and control anthrax.


Assuntos
Antraz/epidemiologia , Bacillus anthracis/genética , Filogenia , Antraz/diagnóstico , Antraz/microbiologia , Bacillus anthracis/isolamento & purificação , China/epidemiologia , Surtos de Doenças , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Repetições Minissatélites , Polimorfismo de Nucleotídeo Único
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