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1.
Molecules ; 29(17)2024 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-39275107

RESUMEN

Bacillus anthracis is a Gram-positive bacterium that can cause acute infection and anthracnose, which is a serious concern for human health. Determining Bacillus anthracis through its spore biomarker dipicolinic acid (DPA) is crucial, and there is a strong need for a method that is rapid, sensitive, and selective. Here, we created Eu(III)-coordination polymers (Eu-CPs) with surfaces that have abundant carboxyl and hydroxyl groups. This was achieved by using citric acid and europium nitrate hexahydrate as precursors in a straightforward one-pot hydrothermal process. These Eu-CPs were then successfully utilized for highly sensitive DPA determination. The fluorescence (FL) emission of Eu-CPs, which is typically weak due to the coordination of Eu(III) with water molecules, was significantly enhanced in the presence of DPA. This enhancement is attributed to the competitive binding between DPA's carboxyl or hydroxyl groups and water molecules. As a result, the absorbed energy of DPA, when excited by 280 nm ultraviolet light, is transferred to Eu-CPs through an antenna effect. This leads to the emission of the characteristic red fluorescence of Eu3+ at 618 nm. A strong linear relationship was observed between the enhanced FL intensity and DPA concentration in the range of 0.5-80 µM. This relationship allowed for a limit of detection (LOD) of 15.23 nM. Furthermore, the Eu-CPs we constructed can effectively monitor the release of DPA from Bacillus subtilis spores, thereby further demonstrating the potential significance of this strategy in the monitoring and management of anthrax risk. This highlights the novelty of this approach in practical applications, provides a valuable determination technique for Bacillus anthracis, and offers insights into the development cycle of microorganisms.


Asunto(s)
Bacillus anthracis , Europio , Ácidos Picolínicos , Polímeros , Ácidos Picolínicos/química , Europio/química , Polímeros/química , Espectrometría de Fluorescencia/métodos , Complejos de Coordinación/química
2.
BMC Infect Dis ; 24(1): 942, 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39251928

RESUMEN

BACKGROUND: Bacillus anthracis is a highly pathogenic bacterium that can cause lethal infection in animals and humans, making it a significant concern as a pathogen and biological agent. Consequently, accurate diagnosis of B. anthracis is critically important for public health. However, the identification of specific marker genes encoded in the B. anthracis chromosome is challenging due to the genetic similarity it shares with B. cereus and B. thuringiensis. METHODS: The complete genomes of B. anthracis, B. cereus, B. thuringiensis, and B. weihenstephanensis were de novo annotated with Prokka, and these annotations were used by Roary to produce the pan-genome. B. anthracis exclusive genes were identified by Perl script, and their specificity was examined by nucleotide BLAST search. A local BLAST alignment was performed to confirm the presence of the identified genes across various B. anthracis strains. Multiplex polymerase chain reactions (PCR) were established based on the identified genes. RESULT: The distribution of genes among 151 whole-genome sequences exhibited three distinct major patterns, depending on the bacterial species and strains. Further comparative analysis between the three groups uncovered thirty chromosome-encoded genes exclusively present in B. anthracis strains. Of these, twenty were found in known lambda prophage regions, and ten were in previously undefined region of the chromosome. We established three distinct multiplex PCRs for the specific detection of B. anthracis by utilizing three of the identified genes, BA1698, BA5354, and BA5361. CONCLUSION: The study identified thirty chromosome-encoded genes specific to B. anthracis, encompassing previously described genes in known lambda prophage regions and nine newly discovered genes from an undefined gene region to the best of our knowledge. Three multiplex PCR assays offer an accurate and reliable alternative method for detecting B. anthracis. Furthermore, these genetic markers have value in anthrax vaccine development, and understanding the pathogenicity of B. anthracis.


Asunto(s)
Bacillus anthracis , Cromosomas Bacterianos , Genoma Bacteriano , Reacción en Cadena de la Polimerasa Multiplex , Bacillus anthracis/genética , Bacillus anthracis/aislamiento & purificación , Reacción en Cadena de la Polimerasa Multiplex/métodos , Cromosomas Bacterianos/genética , Marcadores Genéticos , Carbunco/microbiología , Carbunco/diagnóstico , Humanos , Secuenciación Completa del Genoma/métodos
3.
Pathogens ; 13(8)2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39204299

RESUMEN

The green tea catechin epigallocatechin gallate (EGCg) has antimicrobial effects on many bacteria. In this study, we investigated the inhibitory effects of EGCg on Bacillus anthracis spores and vegetative cells. The B. anthracis spores were insensitive to EGCg, but the growth of vegetative cells derived from germinated spores was inhibited by EGCg. Moreover, EGCg decreased the minimum inhibitory concentration of penicillin and meropenem for penicillin-resistant B. anthracis. In the penicillin-resistant B. anthracis strain, the transcription levels of the beta-lactamase genes (bla1 and bla2) decreased significantly following the treatment with 50 µg/mL EGCg. These results suggest that the appropriate application of EGCg may effectively control the penicillin-resistant B. anthracis growth and beta-lactamase production.

4.
Antimicrob Agents Chemother ; 68(9): e0059524, 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39133023

RESUMEN

Bacillus anthracis, the causative agent of anthrax, is among the most likely bacterial pathogens to be used in a biological attack. Inhalation anthrax is a serious, life-threatening form of infection, and the mortality from acute inhaled anthrax can approach 100% if not treated early and aggressively. Food and Drug Administration-approved antibiotics indicated for post-exposure prophylaxis (PEP) or treatment of anthrax are limited. This study assessed the in vitro activity and in vivo efficacy of omadacycline and comparators against clinical isolates of B. anthracis, including a ciprofloxacin-resistant isolate. Minimum inhibitory concentrations (MICs) of omadacycline, ciprofloxacin, and doxycycline were determined against animal and human clinical isolates of B. anthracis, including the ciprofloxacin-resistant Ames strain BACr4-2. Mice were challenged with aerosolized BACr4-2 spores, and survival was monitored for 28 days post-challenge. Treatment was initiated 24 h after aerosol challenge and administered for 14 days. Omadacycline demonstrated in vitro activity against 53 B. anthracis isolates with an MIC range of ≤0.008-0.25 µg/mL, and an MIC50/MIC90 of 0.015/0.03 µg/mL. Consistent with this, omadacycline demonstrated in vivo efficacy in a PEP mouse model of inhalation anthrax caused by the Ames BACr4-2 ciprofloxacin-resistant B. anthracis isolate. Omadacycline treatment significantly increased survival compared with the vehicle control group and the ciprofloxacin treatment group. As antibiotic resistance rates continue to rise worldwide, omadacycline may offer an alternative PEP or treatment option against inhalation anthrax, including anthrax caused by antibiotic-resistant B. anthracis.


Asunto(s)
Carbunco , Antibacterianos , Bacillus anthracis , Ciprofloxacina , Pruebas de Sensibilidad Microbiana , Tetraciclinas , Ciprofloxacina/farmacología , Bacillus anthracis/efectos de los fármacos , Animales , Carbunco/tratamiento farmacológico , Carbunco/microbiología , Carbunco/mortalidad , Ratones , Antibacterianos/farmacología , Tetraciclinas/farmacología , Tetraciclinas/uso terapéutico , Femenino , Doxiciclina/farmacología , Farmacorresistencia Bacteriana , Humanos , Infecciones del Sistema Respiratorio
5.
Diagn Microbiol Infect Dis ; 110(3): 116473, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39128207

RESUMEN

INTRODUCTION: Due to most likely use of Bacillus anthracis in biological terrorism agents, the rapid and sensitive detection of its spores is crucial in both taking prophylactic measures and proper treatment. This study aimed to develop an amperometric electrochemical immunosensor for the detection of B. anthracis spores. METHODS: A new amperometric biosensor was designed using a combination of magnetic beads and multiplex screen-printed electrodes. This method measures changes in current intensity resulting from oxidation and reduction in the working electrode directly to spore concentrations. RESULTS: A standard curve was formed to test the number of live spores between 2 × 102-2 × 104 spores/ml concentrations. LOD and LOQ values were found to be 92 and 272 spores/ml, respectively. No cross-reactions were seen for Bacillus subtilis, Bacillus cereus and Bacillus thuringiencis spores. CONCLUSIONS: It is shown that the designed Anthrax immunosensor has high sensitivity and selectivity with rapid detection results.


Asunto(s)
Bacillus anthracis , Técnicas Biosensibles , Técnicas Electroquímicas , Esporas Bacterianas , Esporas Bacterianas/aislamiento & purificación , Bacillus anthracis/aislamiento & purificación , Técnicas Biosensibles/métodos , Técnicas Biosensibles/instrumentación , Técnicas Electroquímicas/métodos , Técnicas Electroquímicas/instrumentación , Inmunoensayo/métodos , Inmunoensayo/instrumentación , Límite de Detección , Sensibilidad y Especificidad , Electrodos , Carbunco/diagnóstico , Carbunco/microbiología
6.
BMC Genomics ; 25(1): 742, 2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39080521

RESUMEN

The anthrax-causing bacterium Bacillus anthracis comprises the genetic clades A, B, and C. In the northernmost part (Pafuri) of Kruger National Park (KNP), South Africa, both the common A and rare B strains clades occur. The B clade strains were reported to be dominant in Pafuri before 1991, while A clade strains occurred towards the central parts of KNP. The prevalence of B clade strains is currently much lower as only A clade strains have been isolated from 1992 onwards in KNP. In this study 319 B. anthracis strains were characterized with 31-loci multiple-locus variable-number tandem repeat analysis (MLVA-31). B clade strains from soil (n = 9) and a Tragelaphus strepsiceros carcass (n = 1) were further characterised by whole genome sequencing and compared to publicly available genomes. The KNP strains clustered in the B clade before 1991 into two dominant genotypes. South African strains cluster into a dominant genotype A.Br.005/006 consisting of KNP as well as the other anthrax endemic region, Northern Cape Province (NCP), South Africa. A few A.Br.001/002 strains from both endemic areas were also identified. Subclade A.Br.101 belonging to the A.Br.Aust94 lineage was reported in the NCP. The B-clade strains seems to be vanishing, while outbreaks in South Africa are caused mainly by the A.Br.005/006 genotypes as well as a few minor clades such as A.Br.001/002 and A.Br.101 present in NCP. This work confirmed the existence of the rare and vanishing B-clade strains that group in B.Br.001 branch with KrugerB and A0991 KNP strains.


Asunto(s)
Carbunco , Bacillus anthracis , Filogenia , Bacillus anthracis/genética , Bacillus anthracis/clasificación , Bacillus anthracis/aislamiento & purificación , Sudáfrica , Carbunco/microbiología , Carbunco/epidemiología , Carbunco/veterinaria , Genotipo , Genoma Bacteriano , Microbiología del Suelo , Secuenciación Completa del Genoma
7.
Pathogens ; 13(7)2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39057820

RESUMEN

Bacillus anthracis is a rare but highly dangerous zoonotic bacterial pathogen. At the beginning of this century, a new manifestation of the disease, injectional anthrax, emerged as a result of recreational heroin consumption involving contaminated drugs. The organisms associated with this 13-year-lasting outbreak event in European drug consumers were all grouped into the canonical single-nucleotide polymorphism (canSNP) clade A-branch (A.Br.) 161 of B. anthracis. Related clade A.Br.161 strains of B. anthracis not associated with heroin consumption have also been identified from different countries, mostly in Asia. Because of inadvertent spread by anthropogenic activities, other strains of this A.Br.161 lineage were, however, isolated from several countries. Thus, without additional isolates from this clade, its origin of evolution or its autochthonous region remains obscure. Here, we genomically characterized six new A.Br.161 group isolates, some of which were from Iran, with others likely historically introduced into Germany. All the chromosomes of these isolates could be grouped into a distinct sub-clade within the A.Br.161 clade. This sub-clade is separated from the main A.Br.161 lineage by a single SNP. We have developed this SNP into a PCR assay facilitating the future attribution of strains to this group.

8.
Curr Med Chem ; 2024 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-39005126

RESUMEN

Bacillus anthracis is a causative agent of the highly mortal disease anthrax. This zoonosis is present in nature, but it is also considered one of the most powerful biological warfare agents. A timely diagnosis is necessary for proper therapy and setting of epidemiological countermeasures. Current diagnostic methods should be used in specialized laboratories or medical facilities because there are only a limited number of methods suitable as hand-held assays or even point-of-care tests for detecting B. anthracis or anthrax diagnosis. The lateral flow tests are an exception in this regard, but these tests also have some limitations. Significant progress has been achieved in point-of-care tests for B. anthracis detection and anthrax diagnosis in various biosensors and bioassays. This review focuses on current hand-held and point-of-care tests that can easily prove anthrax or its causative agent outside the context of specialized facilities.

9.
Infect Genet Evol ; 123: 105649, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39059732

RESUMEN

Priestia is a genus that was renamed from the genus Bacillus based on the conserved signature indels (CSIs) in protein sequences that separate Priestia species from Bacillus, with the latter only including species closely related to B. subtilis and B. cereus. Diagnosis of anthrax, a zoonotic disease, is implicated by tripartite anthrax virulence genes (lef, pagA, and cya) and poly-γ-D-glutamic acid capsular genes cap-ABCDE of Bacillus anthracis. Due to the amplification of anthrax virulence genes in Priestia isolates, the search for homologous anthrax virulence genes within the Priestia genomes (n = 9) isolated from animal blood smears was embarked upon through whole genome sequencing. In silico taxonomic identification of the isolates was conducted using genome taxonomy database (GTDB), average nucleotide identity (ANI), and multi-locus sequence typing (MLST), which identified the genomes as P. aryabhattai (n = 5), P. endophytica (n = 2) and P. megaterium (n = 2). A pan-genome analysis was further conducted on the Priestia genomes, including the screening of virulence, antibiotic resistance genes and mobile genetic elements on the sequenced genomes. The oligoribonuclease NrnB protein sequences showed that Priestia spp. possess a unique CSI that is absent in other Bacillus species. Furthermore, the CSI in P. endophytica is unique from other Priestia spp. Pan-genomic analysis indicates that P. endophytica clusters separately from P. aryabhattai and P. megaterium. In silico BLASTn genome analysis using the SYBR primers, Taqman probes and primers that target the chromosomal marker (Ba-1), protective antigen (pagA), and lethal factor (lef) on B. anthracis, showed partial binding to Priestia regions encoding for hypothetical proteins, pyridoxine biosynthesis, hydrolase, and inhibitory proteins. The antibiotic resistance genes (ARG) profile of Priestia spp. showed that the genomes contained no more than two ARGs. This included genes conferring resistance to rifamycin and fosfomycin on P. endophytica, as well as clindamycin on P. aryabhattai and P. megaterium. Priestia genomes lacked B. anthracis plasmids and consisted of plasmid replicon types with unknown functions. Furthermore, the amplification of Priestia strains may result in false positives when qPCR is used to detect the virulence genes of B. anthracis in soil, blood smears, and/or environmental samples.


Asunto(s)
Carbunco , Genoma Bacteriano , Filogenia , Carbunco/microbiología , Carbunco/epidemiología , Animales , Parques Recreativos , Factores de Virulencia/genética , Secuenciación Completa del Genoma , Tipificación de Secuencias Multilocus , Bacillus/genética , Bacillus/aislamiento & purificación , Bacillus/clasificación , Bacillus anthracis/genética , Bacillus anthracis/clasificación
10.
Biophys Chem ; 312: 107273, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38850843

RESUMEN

Bacillus anthracis, the causative agent of anthrax, poses a substantial threat to public health and national security, and is recognized as a potential bioweapon due to its capacity to form resilient spores with enduring viability. Inhalation or ingestion of even minute quantities of aerosolized spores can lead to widespread illness and fatalities, underscoring the formidable lethality of the bacterium. With an untreated mortality rate of 100%, Bacillus anthracis is a disconcerting candidate for bioterrorism. In response to this critical scenario, we employed state-of-the-art computational tools to conceive and characterize flexible RNA aptamer therapeutics tailored for anthrax. The foundational structure of the flexible RNA aptamers was designed by removing the C2'-C3' in each nucleotide unit. Leveraging the crystal structure of Bacillus anthracis ribosomal protein S8 complexed with an RNA aptamer, we explored the structural, dynamic, and energetic aspects of the modified RNA aptamer - S8 protein complexes through extensive all-atom explicit-solvent molecular dynamics simulations (400 ns, 3 replicas each), followed by drawing comparisons to the control system. Our findings demonstrate the enhanced binding competencies of the flexible RNA aptamers to the S8 protein via better shape complementarity and improved H-bond network compared to the control RNA aptamer. This research offers valuable insights into the development of RNA aptamer therapeutics targeting Bacillus anthracis, paving the way for innovative strategies to mitigate the impact of this formidable pathogen.


Asunto(s)
Aptámeros de Nucleótidos , Bacillus anthracis , Simulación de Dinámica Molecular , Proteínas Ribosómicas , Bacillus anthracis/química , Bacillus anthracis/metabolismo , Bacillus anthracis/efectos de los fármacos , Aptámeros de Nucleótidos/química , Aptámeros de Nucleótidos/farmacología , Proteínas Ribosómicas/química , Proteínas Ribosómicas/metabolismo , Proteínas Ribosómicas/antagonistas & inhibidores , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/antagonistas & inhibidores
11.
Clin Microbiol Infect ; 30(9): 1170-1175, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38852852

RESUMEN

OBJECTIVES: Bacillus anthracis clinical breakpoints, representing a systematic approach to guide clinicians in selecting the most appropriate antimicrobial treatments, are not part of the guidance from the European Committee on Antimicrobial Susceptibility Testing (EUCAST). This is because defined distributions of MIC values and of epidemiological cut-off values (ECOFFs) have been lacking. In this study, a Europe-wide network of laboratories in collaboration with EUCAST, aimed at establishing standardized antimicrobial susceptibility testing methods, wild-type MIC distributions, and ECOFFs for ten therapeutically relevant antimicrobials. METHODS: About 335 B. anthracis isolates were tested by broth microdilution and disc diffusion methodologies. MIC and inhibition zone diameters were curated according to EUCAST SOP 10.2 and the results were submitted to EUCAST for ECOFFs and clinical breakpoint determination. RESULTS: Broth microdilution and disc diffusion data distributions revealed putative wild-type distributions for the tested agents. For each antimicrobial agent, ECOFFs were defined. Three highly resistant strains with MIC values of 32 mg/L benzylpenicillin were found. MIC values slightly above the defined ECOFFs were observed in a few isolates, indicating the presence of resistance mechanisms to doxycycline, tetracycline, and amoxicillin. DISCUSSION: B. anthracis antimicrobial susceptibility testing results were used by EUCAST to determine ECOFFs for ten antimicrobial agents. The MIC distributions were used in the process of determining clinical breakpoints. The ECOFFs can be used for the sensitive detection of isolates with resistance mechanisms, and for monitoring resistance development. Genetic changes causing phenotypic shifts in isolates displaying slightly elevated MICs remain to be investigated.


Asunto(s)
Antibacterianos , Bacillus anthracis , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología , Bacillus anthracis/efectos de los fármacos , Bacillus anthracis/genética , Bacillus anthracis/aislamiento & purificación , Humanos , Europa (Continente)/epidemiología , Carbunco/microbiología , Carbunco/epidemiología , Farmacorresistencia Bacteriana
12.
Appl Microbiol Biotechnol ; 108(1): 366, 2024 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-38850320

RESUMEN

This review gathers all, to the best of our current knowledge, known lysins, mainly bacteriophage-derived, that have demonstrated activity against Bacillus anthracis strains. B. anthracis is a spore-forming, toxin-producing bacteria, naturally dwelling in soil. It is best known as a potential biowarfare threat, an etiological agent of anthrax, and a severe zoonotic disease. Anthrax can be treated with antibiotics (ciprofloxacin, penicillin, doxycycline); however, their administration may take up even to 60 days, and different factors can compromise their effectiveness. Bacterial viruses, bacteriophages (phages), are natural enemies of bacteria and use their lytic enzymes, endolysins (lysins), to specifically kill bacterial cells. Harnessing the potential of lysins to combat bacterial infections holds promise for diminishing antibiotic usage and, consequently, addressing the escalating antibiotic resistance in bacteria. In this context, we list the lysins with the activity against B. anthracis, providing a summary of their lytic properties in vitro and the outcomes observed in animal models. Bacillus cereus strain ATCC 4342/RSVF1, a surrogate for B. anthracis, was also included as a target bacteria. KEY POINTS: • More than a dozen different B. anthracis lysins have been identified and studied. • They fall into three blocks regarding their amino acid sequence similarity and most of them are amidases. • Lysins could be used in treating B. anthracis infections.


Asunto(s)
Carbunco , Antibacterianos , Bacillus anthracis , Endopeptidasas , Bacillus anthracis/efectos de los fármacos , Bacillus anthracis/virología , Carbunco/tratamiento farmacológico , Carbunco/microbiología , Animales , Endopeptidasas/farmacología , Endopeptidasas/metabolismo , Endopeptidasas/genética , Antibacterianos/farmacología , Bacteriófagos/genética , Bacillus cereus/efectos de los fármacos , Bacillus cereus/virología , Humanos , Fagos de Bacillus/genética
13.
Antimicrob Agents Chemother ; 68(7): e0011224, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38888319

RESUMEN

Inhalation anthrax is the most severe form of Bacillus anthracis infection, often progressing to fatal conditions if left untreated. While recommended antibiotics can effectively treat anthrax when promptly administered, strains engineered for antibiotic resistance could render these drugs ineffective. Telavancin, a semisynthetic lipoglycopeptide antibiotic, was evaluated in this study as a novel therapeutic against anthrax disease. Specifically, the aims were to (i) assess in vitro potency of telavancin against 17 B. anthracis isolates by minimum inhibitory concentration (MIC) testing and (ii) evaluate protective efficacy in rabbits infected with a lethal dose of aerosolized anthrax spores and treated with human-equivalent intravenous telavancin doses (30 mg/kg every 12 hours) for 5 days post-antigen detection versus a humanized dose of levofloxacin and vehicle control. Blood samples were collected at various times post-infection to assess the level of bacteremia and antibody production, and tissues were collected to determine bacterial load. The animals' body temperatures were also recorded. Telavancin demonstrated potent bactericidal activity against all strains tested (MICs 0.06-0.125 µg/mL). Further, telavancin conveyed 100% survival in this model and cleared B. anthracis from the bloodstream and organ tissues more effectively than a humanized dose of levofloxacin. Collectively, the low MICs against all strains tested and rapid bactericidal in vivo activity demonstrate that telavancin has the potential to be an effective alternative for the treatment or prophylaxis of anthrax infection.


Asunto(s)
Aminoglicósidos , Carbunco , Antibacterianos , Bacillus anthracis , Lipoglucopéptidos , Pruebas de Sensibilidad Microbiana , Infecciones del Sistema Respiratorio , Animales , Lipoglucopéptidos/farmacología , Conejos , Carbunco/tratamiento farmacológico , Carbunco/microbiología , Carbunco/mortalidad , Bacillus anthracis/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Aminoglicósidos/farmacología , Infecciones del Sistema Respiratorio/tratamiento farmacológico , Infecciones del Sistema Respiratorio/microbiología , Modelos Animales de Enfermedad , Levofloxacino/farmacología , Femenino
14.
Microbiol Resour Announc ; 13(7): e0028124, 2024 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-38916302

RESUMEN

In this report, we present the complete genome sequences of two Bacillus anthracis strains utilized as veterinary vaccines in China. The sequencing was conducted using a hybrid assembly methodology that combined Illumina short reads and PacBio long reads. This approach provides a high-quality representative sequence for the strains mentioned above.

15.
Discov Med ; 36(184): 1030-1040, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38798262

RESUMEN

BACKGROUND: Since 2019, the incidence of anthrax in the Ningxia Hui Autonomous Region has increased significantly compared with previous years, so in this situation the anthrax in the Ningxia region not only had a detrimental impact on public health, but also inflicted significant economic repercussions. Therefore, we conducted a molecular epidemiological study of 20 strains from 2019-2023 isolates. This study investigated the origin of Bacillus anthracis and its genetic diversity. METHODS: We conducted canonical single-nucleotide polymorphisms (CanSNPs) typing and whole genome sequencing based on the extracted nucleic acid of Bacillus anthracis. Based on the whole genome drafts, we studied the genomic characteristics of 20 isolates. Meanwhile, we performed phylogenetic studies based on genome-wide core single-nucleotide polymorphisms (SNPs) using MEGA's Maximum Likelihood (ML) method and core-genome-based multilocus sequence typing (cgMLST) of the core genomes of these strains using BioNumerics' minimum spanning tree (MST) model. RESULTS: The 20 isolates were categorized into sub-lineages A.Br.001/002, and comparative genomic analyses of these strains with other isolates from other parts of the world showed that the strains from Ningxia were correlated with isolates from Europe, Indonesia, Georgia (USA), and Beijing (China). For the 20 isolates in Ningxia, the genetic relationship of the isolates isolated from the same year or region was relatively close. CONCLUSION: The A.Br.001/002 subgroup was the dominant endemic strain in Ningxia. The genetic relationship and phylogenesis between isolates from Ningxia and strains from Europe and Indonesia suggest that anthrax spread around the globe through ancient trade routes.


Asunto(s)
Carbunco , Bacillus anthracis , Genoma Bacteriano , Filogenia , Polimorfismo de Nucleótido Simple , Secuenciación Completa del Genoma , Bacillus anthracis/genética , Bacillus anthracis/aislamiento & purificación , Secuenciación Completa del Genoma/métodos , China/epidemiología , Carbunco/microbiología , Carbunco/epidemiología , Genoma Bacteriano/genética , Humanos , Tipificación de Secuencias Multilocus/métodos
16.
Microbiol Spectr ; 12(6): e0418023, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38666793

RESUMEN

The high-consequence pathogen Bacillus anthracis causes human anthrax and often results in lethal infections without the rapid administration of effective antimicrobial treatment. Antimicrobial resistance profiling is therefore critical to inform post-exposure prophylaxis and treatment decisions, especially during emergencies such as outbreaks or where intentional release is suspected. Whole-genome sequencing using a rapid long-read sequencer can uncover antimicrobial resistance patterns if genetic markers of resistance are known. To identify genomic markers associated with antimicrobial resistance, we isolated B. anthracis derived from the avirulent Sterne strain with elevated minimal inhibitory concentrations to clarithromycin. Mutants were characterized both phenotypically through broth microdilution susceptibility testing and observations during culturing, as well as genotypically with whole-genome sequencing. We identified two different in-frame insertions in the L22 ribosomal protein-encoding gene rplV, which were subsequently confirmed to be involved in clarithromycin resistance through the reversion of the mutant gene to the parent (drug-susceptible) sequence. Detection of the rplV insertions was possible with rapid long-read sequencing, with a time-to-answer within 3 h. The mutations associated with clarithromycin resistance described here will be used in conjunction with known genetic markers of resistance for other antimicrobials to strengthen the prediction of antimicrobial resistance in B. anthracis.IMPORTANCEThe disease anthrax, caused by the pathogen Bacillus anthracis, is extremely deadly if not treated quickly and appropriately. Clarithromycin is an antibiotic recommended for the treatment and post-exposure prophylaxis of anthrax by the Centers for Disease Control and Prevention; however, little is known about the ability of B. anthracis to develop resistance to clarithromycin or the mechanism of that resistance. The characterization of clarithromycin-resistant isolates presented here provides valuable information for researchers and clinicians in the event of a release of the resistant strain. Additionally, knowledge of the genetic basis of resistance provides a foundation for susceptibility prediction through rapid genome sequencing to inform timely treatment decisions.


Asunto(s)
Carbunco , Antibacterianos , Bacillus anthracis , Claritromicina , Farmacorresistencia Bacteriana , Pruebas de Sensibilidad Microbiana , Secuenciación Completa del Genoma , Bacillus anthracis/genética , Bacillus anthracis/efectos de los fármacos , Claritromicina/farmacología , Antibacterianos/farmacología , Farmacorresistencia Bacteriana/genética , Carbunco/microbiología , Humanos , Mutación , Proteínas Bacterianas/genética , Proteínas Ribosómicas/genética , Genoma Bacteriano/genética
17.
Antimicrob Agents Chemother ; : e0161023, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38687017

RESUMEN

Efficient treatment of anthrax-related meningitis in patients poses a significant therapeutic challenge. Previously, we demonstrated in our anthrax meningitis rabbit model that ciprofloxacin treatment is ineffective with most of the treated animals succumbing to the infection. Herein we tested the efficacy of doxycycline in our rabbit model and found it highly effective. Since all of our findings are based on a rabbit model, we test the efficacy of ciprofloxacin or doxycycline in a specific central nervous system (CNS) model developed in non-human primates (NHPs). Similar to rabbits, ciprofloxacin treatment was ineffective, while doxycycline protected the infected rhesus macaques (n = 2) from the lethal CNS Bacillus anthracis infection. To test whether the low efficacy of Ciprofloxacin is an example of low efficacy of all fluoroquinolones or only this substance, we treated rabbits that were inoculated intracisterna magna (ICM) with levofloxacin or moxifloxacin. We found that in contrast to ciprofloxacin, levofloxacin and moxifloxacin were highly efficacious in treating lethal anthrax-related meningitis in rabbits and NHP (levofloxacin). We demonstrated (in naïve rabbits) that this difference probably results from variances in blood-brain-barrier penetration of the different fluoroquinolones. The combined treatment of doxycycline and any one of the tested fluoroquinolones was highly effective in the rabbit CNS infection model. The combined treatment of doxycycline and levofloxacin was effective in an inhalation rabbit model, as good as the doxycycline mono-therapy. These findings imply that while ciprofloxacin is highly effective as a post-exposure prophylactic drug, using this drug to treat symptomatic patients should be reconsidered.

18.
Front Cell Infect Microbiol ; 14: 1329235, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38638828

RESUMEN

The metagenomic next-generation sequencing (mNGS) method is preferred for genotyping useful for the identification of organisms, illumination of metabolic pathways, and determination of microbiota. It can accurately obtain all the nucleic acid information in the test sample. Anthrax is one of the most important zoonotic diseases, infecting mainly herbivores and occasionally humans. The disease has four typical clinical forms, cutaneous, gastrointestinal, inhalation, and injection, all of which may result in sepsis or meningitis, with cutaneous being the most common form. Here, we report a case of cutaneous anthrax diagnosed by mNGS in a butcher. Histopathology of a skin biopsy revealed PAS-positive bacilli. Formalin-fixed paraffin-embedded (FFPE) tissue sample was confirmed the diagnosis of anthrax by mNGS. He was cured with intravenous penicillin. To our knowledge, this is the first case of cutaneous anthrax diagnosed by mNGS using FFPE tissue. mNGS is useful for identifying pathogens that are difficult to diagnose with conventional methods, and FFPE samples are simple to manage. Compared with traditional bacterial culture, which is difficult to cultivate and takes a long time, mNGS can quickly and accurately help us diagnose anthrax, so that anthrax can be controlled in a timely manner and prevent the outbreak of epidemic events.


Asunto(s)
Carbunco , Enfermedades Cutáneas Bacterianas , Masculino , Humanos , Carbunco/diagnóstico , Adhesión en Parafina , Formaldehído/uso terapéutico , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Metagenómica/métodos , Sensibilidad y Especificidad
19.
Front Microbiol ; 15: 1304234, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38646635

RESUMEN

Background: Microorganisms are crucial in our ecosystem, offering diverse functions and adaptability. The UNGA Science Summit has underscored the importance of understanding microbes in alignment with the UN Sustainable Development Goals. Bacillus anthracis poses significant challenges among various microorganisms due to its harmful effects on both soil and public health. Our study employed computational techniques to investigate the inhibitory effects of curcumin and mangiferin on Bacillus anthracis, with the aim of presenting a novel bio-based approach to microbial management. Methods: Employing high-throughput screening, we identified potential binding sites on B. anthracis. Molecular docking revealed that curcumin and mangiferin, when synergistically combined, exhibited strong binding affinities at different sites on the bacterium. Our findings demonstrated a significant drop in binding free energy, indicating a stronger interaction when these compounds were used together. Findings: Results of Molecular docking indicated binding energies of -8.45 kcal/mol for mangiferin, -7.68 kcal/mol for curcumin, and a notably higher binding energy of -19.47 kcal/mol for the combination of mangiferin and curcumin with CapD protein. Molecular dynamics simulations further validated these interactions, demonstrating increased stability and structural changes in the bacterium. Conclusion: This study highlights the effectiveness of natural compounds like curcumin and mangiferin in microbial management, especially against challenging pathogens like B. anthracis. It emphasizes the potential of sustainable, nature-based solutions and calls for further empirical research to expand upon these findings.

20.
Clin Case Rep ; 12(3): e8647, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38487638

RESUMEN

This case presents cutaneous anthrax in yak herder from a central highland community in Bhutan. We highlight the clinical presentation, diagnosis and management of the case in a resource-limited setting, and the public health response through the One Health approach.

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