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1.
Geospat Health ; 19(1)2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38619397

RESUMO

Anthrax, a widespread zoonosis in low and middle-income countries with low disease awareness and insufficient livestock vaccination coverage, has been known in Lao Cai Province in northern Vietnam for years before its apparent absence in 2009, which requires investigation as this infection is frequently reported from neighbouring provinces and countries. We aimed to describe the seasonal patterns of anthrax (1991-2008), compare livestock anthrax vaccine coverage to disease occurrence (1991- 2022), and delineate the high-risk areas to inform local disease surveillance in the province. We illustrated the seasonal pattern of anthrax and provided a comparison between livestock vaccine coverage and disease occurrence by purely spatial SaTScan (Poisson model, 25% population at risk) to detect spatial clusters of human and livestock anthrax using population derived from zonal statistics routines. The number of cases, crude cumulative incidence, and spatial clusters of human and livestock anthrax were mapped in QGIS. Results indicate peak anthrax incidence from May to October. Buffalo, domestic cattle, and horses accounted for 75% of total animal cases. Horse anthrax was more common in Lao Cai than in its neighbours and often occurred in years with human mortality. Vaccination covered less than 30% of the livestock population. We found an apparent pattern where anthrax was controlled from 1998-2003 with higher vaccine coverage (>20%) and identified spatial clusters of human and livestock anthrax in Muong Khuong, Bao Thang, and Bac Ha districts of Lao Cai. The local public health and veterinary agencies are recommended to revisit the high-risk areas and communicate with neighbouring provinces for a regional approach to anthrax surveillance and control.


Assuntos
Antraz , Vacinas , Humanos , Bovinos , Animais , Cavalos , Antraz/epidemiologia , Antraz/veterinária , Gado , Laos , Vietnã/epidemiologia
2.
PLoS Negl Trop Dis ; 18(4): e0012067, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38574113

RESUMO

BACKGROUND: Anthrax and brucellosis are endemic national priority zoonotic diseases in Ethiopia. This study assess the possible factors explaining the current limited information available on animal and human cases in pastoral communities. METHODS: Two questionnaire surveys gathered data from 509 pastoralists and 51 healthcare providers between February and April 2019 in five districts of Afar and the Somali region (SRS). RESULTS: Among the 51 healthcare providers, 25 (49%) and 38 (74.5%) had heard of brucellosis, and anthrax, respectively. Of those, only 3 (12%) and 14 (36.8%) knew the symptoms of brucellosis and Anthrax. None of the Health Extension Workers knew any disease symptoms. Healthcare providers recalled two human cases of brucellosis and 39 cases of Anthrax in the last 12 months, based on symptom-based diagnosis. Pastoralists had a moderate level of knowledge about diseases in their animals, with over half (52.4%; n = 267/509) understanding that animals can transmit diseases to people. Overall, 280 out of 508 (55.1%) and 333 out of 507 (65.7%) pastoralists had heard of brucellosis and Anthrax, respectively. Among the latter, 282 (51.3%) knew at least one preventive measure for Anthrax. However, disease knowledge among women was poor. Despite their knowledge, pastoralists engaged in risky unprotected animal handling, animal product consumption/usage as well as husbandry behaviors exposing them to pathogens and favoring the spread of diseases. They identified Anthrax as the most important zoonosis (47.6%) and as one of top three diseases suspected to cause mortality in their livestock. Pastoralists highlighted lack of vaccine coverage, availability and their timely administration. Both, pastoralists and healthcare providers stated the lack of disease awareness and the unavailability of drugs in the market as important challenges. Health facilities lacked protocols and standard operating procedures for managing zoonotic diseases, and did not have access to laboratory confirmation of pathogens. CONCLUSION: Our study revealed significant under-reporting of Anthrax and brucellosis, and weak prevention and response in humans, mostly associated with poor disease knowledge of healthcare providers. Ability to respond to animal outbreaks was limited by vaccine and drugs availability, timely vaccine administration and the mobility of pastoralists.


Assuntos
Antraz , Brucelose , Vacinas , Animais , Humanos , Feminino , Antraz/epidemiologia , Antraz/prevenção & controle , Etiópia/epidemiologia , Somália/epidemiologia , Conhecimentos, Atitudes e Prática em Saúde , Zoonoses/epidemiologia , Zoonoses/prevenção & controle , Brucelose/epidemiologia , Brucelose/prevenção & controle
3.
Front Cell Infect Microbiol ; 14: 1329235, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38638828

RESUMO

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.


Assuntos
Antraz , Dermatopatias Bacterianas , Masculino , Humanos , Antraz/diagnóstico , Inclusão em Parafina , Formaldeído/uso terapêutico , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Metagenômica/métodos , Sensibilidade e Especificidade
4.
Georgian Med News ; (346): 68-79, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38501624

RESUMO

This study explores the application of GIS technologies in analyzing and visualizing spatial structures of especially dangerous infections (EPI) in Kazakhstan. International collaborations have facilitated projects studying the focal patterns of diseases, improving data analysis and visualization. Extensive electronic databases resulting from field research on EPI foci have elevated the study's depth. The dynamics of natural foci, influenced by intraspecific structures of infection carriers, are impacted by industrial and agricultural developments, urban expansions, and climate change. The study notes changes in the enzootic territory, affecting mammal migration and consequently altering natural focus boundaries. Industrial activities, rotational methods, and habitat changes contribute to the increased epidemic potential in enzootic areas. Despite anthropogenic and climatic influences, the prevalence of plague remains high in Kazakhstan, with a trend towards expanding enzootic territories. Unified electronic databases on plague, tularemia, anthrax, and other zoonoses, developed for GIS analysis, enable mapping and visualization of natural foci. Electronic maps aid in determining enzootic territory boundaries, assessing infectious disease activity, and planning preventive measures based on risk assessment. ESRI's ArcGIS Desktop 10.8 with Arc Toolbox modules facilitated data processing in the geoinformation environment. Data includes epidemiological examination results, species composition of carriers, and laboratory test outcomes, enhancing comprehensive analysis and decision-making for anti-epidemic measures. The study in Kazakhstan identifies and details six natural and twenty autonomous plague foci, categorizing them by main carriers and observing an expansion of natural hotspots. The enzootic territory is classified into four geographic zones, further divided into 105 landscape-epidemiological regions. Laboratory studies inform electronic maps for analyzing plague's dynamic situation. Anthrax prevalence, primarily in chernozem and chestnut soils, is assessed, revealing 1,778 unaffected settlements and spatially clustered points. An epidemiological index aids in zoning for anthrax trouble. Tularemia's landscape occurrence is classified into four types, with spatial analysis revealing clusters and potential epidemic danger in specific regions. Geographic information technologies highlight high-risk areas, justifying preventive measures for dangerous infections. The results obtained serve as a scientific justification for the priority of preventive measures within the boundaries of administrative territories characterized by a high degree of potential epidemic danger and objectively indicate the prospects for the introduction of GIS technologies into the practice of epidemiological surveillance of particularly dangerous infections.


Assuntos
Antraz , Peste , Tularemia , Animais , Antraz/epidemiologia , Tularemia/epidemiologia , Cazaquistão/epidemiologia , Sistemas de Informação Geográfica , Mamíferos
5.
Int J Mol Sci ; 25(6)2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38542074

RESUMO

Lethal toxin (LT) is the critical virulence factor of Bacillus anthracis, the causative agent of anthrax. One common symptom observed in patients with anthrax is thrombocytopenia, which has also been observed in mice injected with LT. Our previous study demonstrated that LT induces thrombocytopenia by suppressing megakaryopoiesis, but the precise molecular mechanisms behind this phenomenon remain unknown. In this study, we utilized 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced megakaryocytic differentiation in human erythroleukemia (HEL) cells to identify genes involved in LT-induced megakaryocytic suppression. Through cDNA microarray analysis, we identified Dachshund homolog 1 (DACH1) as a gene that was upregulated upon TPA treatment but downregulated in the presence of TPA and LT, purified from the culture supernatants of B. anthracis. To investigate the function of DACH1 in megakaryocytic differentiation, we employed short hairpin RNA technology to knock down DACH1 expression in HEL cells and assessed its effect on differentiation. Our data revealed that the knockdown of DACH1 expression suppressed megakaryocytic differentiation, particularly in polyploidization. We demonstrated that one mechanism by which B. anthracis LT induces suppression of polyploidization in HEL cells is through the cleavage of MEK1/2. This cleavage results in the downregulation of the ERK signaling pathway, thereby suppressing DACH1 gene expression and inhibiting polyploidization. Additionally, we found that known megakaryopoiesis-related genes, such as FOSB, ZFP36L1, RUNX1, FLI1, AHR, and GFI1B genes may be positively regulated by DACH1. Furthermore, we observed an upregulation of DACH1 during in vitro differentiation of CD34-megakaryocytes and downregulation of DACH1 in patients with thrombocytopenia. In summary, our findings shed light on one of the molecular mechanisms behind LT-induced thrombocytopenia and unveil a previously unknown role for DACH1 in megakaryopoiesis.


Assuntos
Antraz , Bacillus anthracis , Leucemia Eritroblástica Aguda , Trombocitopenia , Animais , Humanos , Camundongos , Antígenos de Bactérias/metabolismo , Bacillus anthracis/metabolismo , Fator 1 de Resposta a Butirato/metabolismo , Diferenciação Celular , Trombocitopenia/induzido quimicamente , Trombocitopenia/genética
6.
NPJ Syst Biol Appl ; 10(1): 33, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38553532

RESUMO

Protective antigen (PA) is a protein produced by Bacillus anthracis. It forms part of the anthrax toxin and is a key immunogen in US and UK anthrax vaccines. In this study, we have conducted experiments to quantify PA in the supernatants of cultures of B. anthracis Sterne strain, which is the strain used in the manufacture of the UK anthrax vaccine. Then, for the first time, we quantify PA production and degradation via mathematical modelling and Bayesian statistical techniques, making use of this new experimental data as well as two other independent published data sets. We propose a single mathematical model, in terms of delay differential equations (DDEs), which can explain the in vitro dynamics of all three data sets. Since we did not heat activate the B. anthracis spores prior to inoculation, germination occurred much slower in our experiments, allowing us to calibrate two additional parameters with respect to the other data sets. Our model is able to distinguish between natural PA decay and that triggered by bacteria via proteases. There is promising consistency between the different independent data sets for most of the parameter estimates. The quantitative characterisation of B. anthracis PA production and degradation obtained here will contribute towards the ambition to include a realistic description of toxin dynamics, the host immune response, and anti-toxin treatments in future mechanistic models of anthrax infection.


Assuntos
Vacinas contra Antraz , Antraz , Bacillus anthracis , Humanos , Teorema de Bayes , Antraz/microbiologia , Antraz/prevenção & controle
7.
Immunohorizons ; 8(3): 269-280, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38517345

RESUMO

Bacillus anthracis peptidoglycan (PGN) is a major component of the bacterial cell wall and a key pathogen-associated molecular pattern contributing to anthrax pathology, including organ dysfunction and coagulopathy. Increases in apoptotic leukocytes are a late-stage feature of anthrax and sepsis, suggesting there is a defect in apoptotic clearance. In this study, we tested the hypothesis that B. anthracis PGN inhibits the capacity of human monocyte-derived macrophages (MΦ) to efferocytose apoptotic cells. Exposure of CD163+CD206+ MΦ to PGN for 24 h impaired efferocytosis in a manner dependent on human serum opsonins but independent of complement component C3. PGN treatment reduced cell surface expression of the proefferocytic signaling receptors MERTK, TYRO3, AXL, integrin αVß5, CD36, and TIM-3, whereas TIM-1, αVß3, CD300b, CD300f, STABILIN-1, and STABILIN-2 were unaffected. ADAM17 is a major membrane-bound protease implicated in mediating efferocytotic receptor cleavage. We found multiple ADAM17-mediated substrates increased in PGN-treated supernatant, suggesting involvement of membrane-bound proteases. ADAM17 inhibitors TAPI-0 and Marimastat prevented TNF release, indicating effective protease inhibition, and modestly increased cell-surface levels of MerTK and TIM-3 but only partially restored efferocytic capacity by PGN-treated MΦ. We conclude that human serum factors are required for optimal recognition of PGN by human MΦ and that B. anthracis PGN inhibits efferocytosis in part by reducing cell surface expression of MERTK and TIM-3.


Assuntos
Antraz , Bacillus anthracis , Humanos , c-Mer Tirosina Quinase/metabolismo , Peptidoglicano/farmacologia , Peptidoglicano/metabolismo , Antraz/metabolismo , Antraz/patologia , 60574 , Receptor Celular 2 do Vírus da Hepatite A/metabolismo , Macrófagos/metabolismo , Parede Celular/metabolismo , Parede Celular/patologia
8.
mBio ; 15(4): e0018624, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38511933

RESUMO

Melioidosis, caused by the intracellular bacterial pathogen and Tier 1 select agent Burkholderia pseudomallei (Bp), is a highly fatal disease endemic in tropical areas. No licensed vaccine against melioidosis exists. In preclinical vaccine studies, demonstrating protection against respiratory infection in the highly sensitive BALB/c mouse has been especially challenging. To address this challenge, we have used a safe yet potent live attenuated platform vector, LVS ΔcapB, previously used successfully to develop vaccines against the Tier 1 select agents of tularemia, anthrax, and plague, to develop a melioidosis vaccine. We have engineered melioidosis vaccines (rLVS ΔcapB/Bp) expressing multiple immunoprotective Bp antigens among type VI secretion system proteins Hcp1, Hcp2, and Hcp6, and membrane protein LolC. Administered intradermally, rLVS ΔcapB/Bp vaccines strongly protect highly sensitive BALB/c mice against lethal respiratory Bp challenge, but protection is overwhelmed at very high challenge doses. In contrast, administered intranasally, rLVS ΔcapB/Bp vaccines remain strongly protective against even very high challenge doses. Under some conditions, the LVS ΔcapB vector itself provides significant protection against Bp challenge, and consistent with this, both the vector and vaccines induce humoral immune responses to Bp antigens. Three-antigen vaccines expressing Hcp6-Hcp1-Hcp2 or Hcp6-Hcp1-LolC are among the most potent and provide long-term protection and protection even with a single intranasal immunization. Protection via the intranasal route was either comparable to or statistically significantly better than the single-deletional Bp mutant Bp82, which served as a positive control. Thus, rLVS ΔcapB/Bp vaccines are exceptionally promising safe and potent melioidosis vaccines. IMPORTANCE: Melioidosis, a major neglected disease caused by the intracellular bacterial pathogen Burkholderia pseudomallei, is endemic in many tropical areas of the world and causes an estimated 165,000 cases and 89,000 deaths in humans annually. Moreover, B. pseudomallei is categorized as a Tier 1 select agent of bioterrorism, largely because inhalation of low doses can cause rapidly fatal pneumonia. No licensed vaccine is available to prevent melioidosis. Here, we describe a safe and potent melioidosis vaccine that protects against lethal respiratory challenge with B. pseudomallei in a highly sensitive small animal model-even a single immunization is highly protective, and the vaccine gives long-term protection. The vaccine utilizes a highly attenuated replicating intracellular bacterium as a vector to express multiple key proteins of B. pseudomallei; this vector platform has previously been used successfully to develop potent vaccines against other Tier 1 select agent diseases including tularemia, anthrax, and plague.


Assuntos
Antraz , Burkholderia pseudomallei , Melioidose , Peste , Tularemia , Humanos , Animais , Camundongos , Burkholderia pseudomallei/genética , Melioidose/prevenção & controle , Camundongos Endogâmicos BALB C , Vacinas Bacterianas , Vacinas Atenuadas , Antígenos de Bactérias/genética
9.
J Zoo Wildl Med ; 55(1): 212-218, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38453505

RESUMO

Improved methods are needed to prevent wildlife deaths from anthrax. Caused by Bacillus anthracis, naturally occurring outbreaks of anthrax are frequent but unpredictable. The commercially available veterinary vaccine is labeled for subcutaneous injection and is impractical for large-scale wildlife vaccination programs; therefore, oral vaccination is the most realistic method to control and prevent these outbreaks. We reported the induction of an anthrax-specific lethal toxin (LeTx) neutralizing antibody response in mice following oral vaccination with alginate microcapsules containing B. anthracis Sterne strain 34F2 spores, coated with poly-L-lysine (PLL) and vitelline protein B (VpB). We continued evaluating our novel vaccine formulation through this proof-of-concept study in white-tailed deer (WTD; Odocoileus virginianus; n = 9). We orally vaccinated WTD via needle-free syringe with three formulations of the encapsulated vaccine: 1) PLL-VpB-coated microcapsules with 107-8 spores/ml (n = 5), 2) PLL-VpB-coated microcapsules with 109-10 spores/ml (n = 2), and 3) PLL-coated microcapsules with 109-10 spores/ml (n = 2). Although the limited sample sizes require continued experimentation, we observed an anthrax-specific antibody response in WTD serum following oral vaccination with PLL-coated microcapsules containing 109 spores/ ml. Furthermore, this antibody response neutralized anthrax LeTx in vitro, suggesting that continued development of this vaccine may allow for realistic wildlife anthrax vaccination programs.


Assuntos
Vacinas contra Antraz , Antraz , Bacillus anthracis , Cervos , Doenças dos Roedores , Animais , Camundongos , Antraz/prevenção & controle , Antraz/veterinária , Anticorpos Neutralizantes , Cápsulas , Espectroscopia de Ressonância de Spin Eletrônica/veterinária , Vacinação/veterinária , Animais Selvagens , Anticorpos Antibacterianos
10.
Toxins (Basel) ; 16(2)2024 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-38393144

RESUMO

Institut Pasteur and Bacillus anthracis have enjoyed a relationship lasting almost 120 years, starting from its foundation and the pioneering work of Louis Pasteur in the nascent fields of microbiology and vaccination, and blooming after 1986 following the molecular biology/genetic revolution. This contribution will give a historical overview of these two research eras, taking advantage of the archives conserved at Institut Pasteur. The first era mainly focused on the production, characterisation, surveillance and improvement of veterinary anthrax vaccines; the concepts and technologies with which to reach a deep understanding of this research field were not yet available. The second period saw a new era of B. anthracis research at Institut Pasteur, with the anthrax laboratory developing a multi-disciplinary approach, ranging from structural analysis, biochemistry, genetic expression, and regulation to bacterial-host cell interactions, in vivo pathogenicity, and therapy development; this led to the comprehensive unravelling of many facets of this toxi-infection. B. anthracis may exemplify some general points on how science is performed in a given society at a given time and how a scientific research domain evolves. A striking illustration can be seen in the additive layers of regulations that were implemented from the beginning of the 21st century and their impact on B. anthracis research. B. anthracis and anthrax are complex systems that raise many valuable questions regarding basic research. One may hope that B. anthracis research will be re-initiated under favourable circumstances later at Institut Pasteur.


Assuntos
Antraz , Bacillus anthracis , Toxinas Bacterianas , Humanos , Bacillus anthracis/metabolismo , Antraz/microbiologia , Carvão Vegetal , Toxinas Bacterianas/metabolismo , Virulência , Antígenos de Bactérias/genética
13.
Proc Biol Sci ; 291(2016): 20232568, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38320613

RESUMO

An important part of infectious disease management is predicting factors that influence disease outbreaks, such as R, the number of secondary infections arising from an infected individual. Estimating R is particularly challenging for environmentally transmitted pathogens given time lags between cases and subsequent infections. Here, we calculated R for Bacillus anthracis infections arising from anthrax carcass sites in Etosha National Park, Namibia. Combining host behavioural data, pathogen concentrations and simulation models, we show that R is spatially and temporally variable, driven by spore concentrations at death, host visitation rates and early preference for foraging at infectious sites. While spores were detected up to a decade after death, most secondary infections occurred within 2 years. Transmission simulations under scenarios combining site infectiousness and host exposure risk under different environmental conditions led to dramatically different outbreak dynamics, from pathogen extinction (R < 1) to explosive outbreaks (R > 10). These transmission heterogeneities may explain variation in anthrax outbreak dynamics observed globally, and more generally, the critical importance of environmental variation underlying host-pathogen interactions. Notably, our approach allowed us to estimate the lethal dose of a highly virulent pathogen non-invasively from observational studies and epidemiological data, useful when experiments on wildlife are undesirable or impractical.


Assuntos
Antraz , Bacillus anthracis , Coinfecção , Animais , Animais Selvagens , Estações do Ano
14.
BMC Public Health ; 24(1): 632, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38418986

RESUMO

BACKGROUND: In Zimbabwe, anthrax is endemic with outbreaks being reported almost annually in livestock, wildlife, and humans over the past 40 years. Accurate modelling of its spatial distribution is key in formulating effective control strategies. In this study, an Ensemble Species Distribution Model was used to model the current and future distribution of anthrax occurrence in Zimbabwe. METHODS: Bioclimatic variables derived from the Beijing Climate Centre Climate System Model were used to model the disease. Collinearity testing was conducted on the 19 bioclimatic variables and elevation to remove redundancy. Variables that had no collinearity were used for anthrax habitat suitability modelling. Two future climate change scenarios for different Representative Concentration Pathways (RCP), RCP4.5 and RCP8.5 were used. Model evaluation was done using true skill, Kappa statistics and receiver operating characteristics. RESULTS: The results showed that under current bioclimatic conditions, eastern and western districts of Zimbabwe were modelled as highly suitable, central districts moderately suitable and southern parts marginally suitable for anthrax occurrence. Future predictions demonstrated that the suitable (8%) and highly suitable (7%) areas for anthrax occurrence would increase under RCP4.5 scenario. In contrast, a respective decrease (11%) and marginal increase (0.6%) of suitable and highly suitable areas for anthrax occurrence were predicted under the RCP8.5 scenario. The percentage contribution of the predictors varied for the different scenarios; Bio6 and Bio18 for the current scenario, Bio2, Bio4 and Bio9 for the RCP4.5 and Bio3 and Bio15 for the RCP8.5 scenarios. CONCLUSIONS: The study revealed that areas currently suitable for anthrax should be targeted for surveillance and prevention. The predicted future anthrax distribution can be used to guide and prioritise surveillance and control activities and optimise allocation of limited resources. In the marginally to moderately suitable areas, effective disease surveillance systems and awareness need to be put in place for early detection of outbreaks. Targeted vaccinations and other control measures including collaborative 'One Health' strategies need to be implemented in the predicted highly suitable areas. In the southern part where a high decrease in suitability was predicted, continued monitoring would be necessary to detect incursions early.


Assuntos
Antraz , Animais , Humanos , Antraz/epidemiologia , Antraz/veterinária , Mudança Climática , Zimbábue/epidemiologia , Ecossistema , Animais Selvagens
15.
Antimicrob Agents Chemother ; 68(3): e0149723, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38358266

RESUMO

Bacillus anthracis is a Gram-positive Centers for Disease Control and Prevention category "A" biothreat pathogen. Without early treatment, inhalation of anthrax spores with progression to inhalational anthrax disease is associated with high fatality rates. Gepotidacin is a novel first-in-class triazaacenaphthylene antibiotic that inhibits bacterial DNA replication by a distinct mechanism of action and is being evaluated for use against biothreat and conventional pathogens. Gepotidacin selectively inhibits bacterial DNA replication via a unique binding mode and has in vitro activity against a collection of B. anthracis isolates including antibacterial-resistant strains, with the MIC90 ranging from 0.5 to 1 µg/mL. In vivo activity of gepotidacin was also evaluated in the New Zealand White rabbit model of inhalational anthrax. The primary endpoint was survival, with survival duration and bacterial clearance as secondary endpoints. The trigger for treatment was the presence of anthrax protective antigen in serum. New Zealand White rabbits were dosed intravenously for 5 days with saline or gepotidacin at 114 mg/kg/d to simulate a dosing regimen of 1,000 mg intravenous (i.v.) three times a day (TID) in humans. Gepotidacin provided a survival benefit compared to saline control, with 91% survival (P-value: 0.0001). All control animals succumbed to anthrax and were found to be blood- and organ culture-positive for B. anthracis. The novel mode of action, in vitro microbiology, preclinical safety, and animal model efficacy data, which were generated in line with Food and Drug Administration Animal Rule, support gepotidacin as a potential treatment for anthrax in an emergency biothreat situation.


Assuntos
Acenaftenos , Vacinas contra Antraz , Antraz , Bacillus anthracis , Compostos Heterocíclicos com 3 Anéis , Infecções Respiratórias , Coelhos , Humanos , Animais , Antraz/microbiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Modelos Animais de Doenças , Vacinas contra Antraz/uso terapêutico
16.
Acta Trop ; 252: 107128, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38309609

RESUMO

Even though anthrax is a disease of antiquity that has been studied for centuries, serious concerns have been raised about our understanding of its epidemiology. Since the 1960s, we have based the epidemiology of anthrax on the results of dose-dependent experiments, especially those involving cattle at that time. In this species the experiments demonstrated that the severity of infection was dependent upon the numbers of Bacillus anthracis spores ingested. The opinion was that ingesting only a few spores would be insufficient to cause an apparent infection; any infection that resulted would be latent (i.e., unrecognized). Based on the results of these experiments, it was accepted that the ingestion of large numbers of spores was the source of infection for hundreds of anthrax outbreaks. However, many investigations of both human and animal anthrax outbreaks have failed to identify sources of large numbers of spores, suggesting that these outbreaks are only rarely a consequence of ingestion or inhalation of large quantities of spores. This opinion piece builds upon the indirect evidence previously presented in an article focused on the existence of latent infections. Much of the evidence for the existence of latent infections was predicated upon a reduction of host resistance, which revealed how latent infections could be a source of more severe forms of the infection. That is, a latent infection can be the source of a severe infection, but the cause of the severe infection is the reduced host resistance. That first article concentrated on the arguments for latent infections, while this article concentrates on the arguments for host resistance. Host resistance is virtually impossible to measure objectively in the field. To provide a subjective measure of host resistance during anthrax outbreaks, we suggest the use of the opinions of livestock owners and or their veterinary practitioners and or field workers during investigations of anthrax outbreaks. When veterinary personal work in the field they are much like field biologists. In some ways field biologists better appreciate environmental factors, population ecology and other perspectives that are of use to epidemiologists. The more diverse the information the better the epidemiology is understood. To this effect we present our personal anecdotal and theoretical ideas from our experiences as well as a collection of bibliographic observations from others'. Our conclusions are that a combination of latent infections and reduced host resistance based on the host's relationship with its environment would better explain the epidemiology of severe infections in anthrax outbreaks for which large quantities of spores have not been located. This applies especially if the area has a history of the disease and/or if necropsies have shown the presence of latent infections in otherwise normal animals in the area and/or if environmental conditions are considered stressful and include intense insect activity.


Assuntos
Antraz , Bacillus anthracis , Infecção Latente , Animais , Humanos , Bovinos , Antraz/epidemiologia , Antraz/veterinária , Surtos de Doenças/veterinária , Ecologia , Infecção Latente/epidemiologia
17.
J Public Health Manag Pract ; 30(2): 231-239, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38271105

RESUMO

CONTEXT: The Centers for Disease Control and Prevention (CDC) and the US Postal Service (USPS) consider anthrax to be a potential threat to USPS workers. A county health department-owned pharmacy supports local USPS response in the event of an exposure. The pharmacy team identified the need to review and update the local anthrax response plan. PROGRAM/POLICY: A Pharmacy Point-of-Dispensing Toolkit and response plan for initial 10-day post-exposure antibiotic prophylaxis was developed for use by a local health department in the event of a mass anthrax exposure at a US Post Office sorting facility. The pharmacist's role in medical countermeasures planning for anthrax exposure is also discussed to illustrate how pharmacists' medication expertise can be utilized. EVALUATION: The CDC's Public Health Preparedness Capabilities: National Standards for State and Local Planning framework and inputs from an interprofessional stakeholder team were used to develop a Medical Countermeasures Response Plan and Implementation Toolkit for mass point-of-dispensing (POD) in the event of an anthrax exposure. IMPLEMENTATION AND DISSEMINATION: Stakeholders attended a USPS Community Partner Training event where additional revisions to the toolkit were made. The toolkit and standing order are now implemented at the local health department to be reviewed and updated on a yearly basis by health department leadership. DISCUSSION: Pharmacists can use their medication expertise and experience with patient education to design emergency response plans focused on increasing patient safety and medication adherence. Pharmacists should be involved in emergency response and medical countermeasures planning that involve medications.


Assuntos
Antraz , Farmácia , Humanos , Antraz/tratamento farmacológico , Antraz/prevenção & controle , Profilaxia Pós-Exposição , Farmacêuticos , Saúde Pública
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 310: 123964, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38286080

RESUMO

In this work, a stable ratiometric nanofluorescent probe for the detection of 2,6-dipicolinic acid (DPA), a Bacillus anthracis biomarker, was developed based on confinement-induced emission enhancement of cationic styrylpyridine salt derivative L in MCM-22 molecular sieve pores. The cationic L and the lanthanide Tb3+ were loaded into the pores of the molecular sieve by electrostatic interaction with the negatively charged AlO4 tetrahedron unit, and L exhibited enhanced red fluorescence emission as a stable fluorescence reference mark in the nanoprobe platform due to the restricted molecular torsion of L in the pores of MCM-22. At the same time, the characteristic green fluorescence emission of Tb3+ can be excited by energy transfer due to the "antenna effect" of DPA. The prepared Tb-L@MCM-22 nanoprobe showed specific selectivity and stable fluorescence ratiometric detection of DPA in tap water, lake water, bovine serum and actual bacterial spores. Benefiting from the confinement-induced fluorescence enhancement effect of L in the MCM-22 molecular sieve pores, the obtained Tb-L@MCM-22 can provide a stable reference signal for the fluorescence ratiometric detection of DPA with a limit of detection (LOD) of 78.6 nM and 1.310 × 104 spores per mL. More importantly, combining of the Tb-L@MCM-22 based DPA detection test strips with a smartphone app demonstrated a stable, convenient and rapid method for detecting of anthrax biomarkers.


Assuntos
Antraz , Bacillus anthracis , Humanos , Fluorescência , Piridinas , Ácidos Picolínicos , Antraz/diagnóstico , Cloreto de Sódio , Biomarcadores , Água , Corantes Fluorescentes
20.
Appl Microbiol Biotechnol ; 108(1): 76, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38194144

RESUMO

Bacillus anthracis is an etiological agent of anthrax, a severe zoonotic disease that can be transmitted to people and cause high mortalities. Bacteriophages and their lytic enzymes, endolysins, have potential therapeutic value in treating infections caused by this bacterium as alternatives or complements to antibiotic therapy. They can also be used to identify and detect B. anthracis. Endolysins of two B. anthracis Wbetavirus phages, J5a and F16Ba which were described by us recently, differ significantly from the best-known B. anthracis phage endolysin PlyG from Wbetavirus genus bacteriophage Gamma and a few other Wbetavirus genus phages. They are larger than PlyG (351 vs. 233 amino acid residues), contain a signal peptide at their N-termini, and, by prediction, have a different fold of cell binding domain suggesting different structural basis of cell epitope recognition. We purified in a soluble form the modified versions of these endolysins, designated by us LysJ and LysF, respectively, and depleted of signal peptides. Both modified endolysins could lyse the B. anthracis cell wall in zymogram assays. Their activity against the living cells of B. anthracis and other species of Bacillus genus was tested by spotting on the layers of bacteria in soft agar and by assessing the reduction of optical density of bacterial suspensions. Both methods proved the effectiveness of LysJ and LysF in killing the anthrax bacilli, although the results obtained by each method differed. Additionally, the lytic efficiency of both proteins was different, which apparently correlates with differences in their amino acid sequence. KEY POINTS: • LysJ and LysF are B. anthracis-targeting lysins differing from lysins studied so far • LysJ and LysF could be overproduced in E. coli in soluble and active forms • LysJ and LysF are active in killing cells of B. anthracis virulent strains.


Assuntos
Antraz , Bacillus anthracis , Bacillus , Bacteriófagos , Humanos , Escherichia coli
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