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1.
Med Trop Sante Int ; 4(1)2024 03 31.
Artigo em Francês | MEDLINE | ID: mdl-38846127

RESUMO

Introduction: Brucellosis in marine mammals (cetacean and pinnipeds) has emerged in a very significant way during the last two decades. Currently Brucella ceti and Brucella pinnipedialis are the two recognized species in marine mammals, but available information is still limited. Several genotypes have been identified, and studies on the relationship between sequence type (ST) and organ pathogenicity or tropism have indicated differences in pathogenesis between B. ceti sequences in cetaceans. The zoonotic potential of this disease is based on the identification of the main sources of introduction and spread of Brucella spp. in the marine environment as well as on the factors of exposure of marine mammals and humans to the bacteria. Bibliographic review: This article is a bibliographical review on marine mammal brucellosis, including the features, sources and transmission modes of each Brucella species, as well as their potential pathogenicity in animals and humans. Conclusion: Different genotypes of marine Brucella spp have been isolated from marine mammal species but without any evidence of pathology induced by these bacteria. Associated lesions are variable and include subcutaneous abscesses, meningo-encephalomyelitis, pneumonia, myocarditis, osteoarthritis, orchitis, endometritis, placentitis and abortion. The isolation of marine B. spp from marine mammal respiratory parasites associated to lung injury has raised the intriguing possibility that they may serve as a vector for the transmission of this bacterium.The severity of marine B. spp remains unknown due to the lack of an estimate of the prevalence of this disease in marine mammals. The number of suspected human cases is still very limited. However, by analogy with other germs of the genus Brucella responsible for abortion in ruminants and for a febrile and painful state in human beings, prevention measures are essential. The significant increase in the number of strandings coupled with a high seroprevalence in certain species of marine mammals must be considered for people in direct or indirect contact with these animals. Ongoing epidemiological monitoring combined with extensive post-mortem examinations (necropsy, bacteriology and sequencing) of all species of stranded marine mammals would deepen knowledge on the zoonotic potential of marine Brucella species.


Assuntos
Brucella , Brucelose , Caniformia , Cetáceos , Animais , Brucelose/transmissão , Brucelose/veterinária , Brucelose/microbiologia , Brucelose/epidemiologia , Humanos , Brucella/patogenicidade , Brucella/isolamento & purificação , Brucella/genética , Cetáceos/microbiologia , Caniformia/microbiologia , Zoonoses/microbiologia , Zoonoses/transmissão
2.
mBio ; 15(7): e0072624, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38847540

RESUMO

The modulation of actin polymerization is a common theme among microbial pathogens. Even though microorganisms show a wide repertoire of strategies to subvert the activity of actin, most of them converge in the ones that activate nucleating factors, such as the Arp2/3 complex. Brucella spp. are intracellular pathogens capable of establishing chronic infections in their hosts. The ability to subvert the host cell response is dependent on the capacity of the bacterium to attach, invade, avoid degradation in the phagocytic compartment, replicate in an endoplasmic reticulum-derived compartment and egress. Even though a significant number of mechanisms deployed by Brucella in these different phases have been identified and characterized, none of them have been described to target actin as a cellular component. In this manuscript, we describe the identification of a novel virulence factor (NpeA) that promotes niche formation. NpeA harbors a short linear motif (SLiM) present within an amphipathic alpha helix that has been described to bind the GTPase-binding domain (GBD) of N-WASP and stabilizes the autoinhibited state. Our results show that NpeA is secreted in a Type IV secretion system-dependent manner and that deletion of the gene diminishes the intracellular replication capacity of the bacterium. In vitro and ex vivo experiments demonstrate that NpeA binds N-WASP and that the short linear motif is required for the biological activity of the protein.IMPORTANCEThe modulation of actin-binding effectors that regulate the activity of this fundamental cellular protein is a common theme among bacterial pathogens. The neural Wiskott-Aldrich syndrome protein (N-WASP) is a protein that several pathogens target to hijack actin dynamics. The highly adapted intracellular bacterium Brucella has evolved a wide repertoire of virulence factors that modulate many activities of the host cell to establish successful intracellular replication niches, but, to date, no effector proteins have been implicated in the modulation of actin dynamics. We present here the identification of a virulence factor that harbors a short linear motif (SLiM) present within an amphipathic alpha helix that has been described to bind the GTPase-binding domain (GBD) of N-WASP stabilizing its autoinhibited state. We demonstrate that this protein is a Type IV secretion effector that targets N-WASP-promoting intracellular survival and niche formation.


Assuntos
Proteínas de Bactérias , Fatores de Virulência , Proteína Neuronal da Síndrome de Wiskott-Aldrich , Fatores de Virulência/metabolismo , Fatores de Virulência/genética , Proteína Neuronal da Síndrome de Wiskott-Aldrich/metabolismo , Proteína Neuronal da Síndrome de Wiskott-Aldrich/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Humanos , Sistemas de Secreção Tipo IV/metabolismo , Sistemas de Secreção Tipo IV/genética , Animais , Camundongos , Ligação Proteica , Brucella/metabolismo , Brucella/genética , Brucella/patogenicidade , Motivos de Aminoácidos , Actinas/metabolismo , Brucelose/microbiologia , Macrófagos/microbiologia , Interações Hospedeiro-Patógeno
3.
J Clin Microbiol ; 61(8): e0043823, 2023 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-37395662

RESUMO

Bacteria of the genus Brucella are facultative intracellular parasites that cause brucellosis, a severe animal and human disease. Recently, a group of taxonomists merged the brucellae with the primarily free-living, phylogenetically related Ochrobactrum spp. in the genus Brucella. This change, founded only on global genomic analysis and the fortuitous isolation of some opportunistic Ochrobactrum spp. from medically compromised patients, has been automatically included in culture collections and databases. We argue that clinical and environmental microbiologists should not accept this nomenclature, and we advise against its use because (i) it was presented without in-depth phylogenetic analyses and did not consider alternative taxonomic solutions; (ii) it was launched without the input of experts in brucellosis or Ochrobactrum; (iii) it applies a non-consensus genus concept that disregards taxonomically relevant differences in structure, physiology, population structure, core-pangenome assemblies, genome structure, genomic traits, clinical features, treatment, prevention, diagnosis, genus description rules, and, above all, pathogenicity; and (iv) placing these two bacterial groups in the same genus creates risks for veterinarians, medical doctors, clinical laboratories, health authorities, and legislators who deal with brucellosis, a disease that is particularly relevant in low- and middle-income countries. Based on all this information, we urge microbiologists, bacterial collections, genomic databases, journals, and public health boards to keep the Brucella and Ochrobactrum genera separate to avoid further bewilderment and harm.


Assuntos
Brucella , Ochrobactrum , Ochrobactrum/classificação , Ochrobactrum/genética , Ochrobactrum/patogenicidade , Ochrobactrum/fisiologia , Brucella/classificação , Brucella/genética , Brucella/patogenicidade , Brucella/fisiologia , Terminologia como Assunto , Filogenia , Brucelose/tratamento farmacológico , Brucelose/microbiologia , Humanos , Infecções Oportunistas/microbiologia
4.
PLoS One ; 17(1): e0262551, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35025975

RESUMO

Brucellae are intracellular sneaky bacteria and they can elude the host's defensive mechanisms, resulting in therapeutic failure. Therefore, the goal of this investigation was to rapid identification of Brucella species collected from animals and humans in Saudi Arabia, as well as to evaluate their resistance to antibiotics. On selective media, 364 animal samples as well as 70 human blood samples were cultured. Serological and biochemical approaches were initially used to identify a total of 25 probable cultured isolates. The proteomics of Brucella species were identified using the MALDI Biotyper (MBT) system, which was subsequently verified using real-time polymerase chain reaction (real-time PCR) and microfluidic electrophoresis assays. Both Brucella melitensis (B. melitensis) and Brucella abortus (B. abortus) were tested for antimicrobial susceptibility using Kirby Bauer method and the E-test. In total, 25 samples were positive for Brucella and included 11 B. melitensis and 14 B. abortus isolates. Twenty-two out of 25 (88%) and 24/25 (96%) of Brucella strains were recognized through the Vitek 2 Compact system. While MBT was magnificently identified 100% of the strains at the species level with a score value more than or equal to 2.00. Trimethoprim-sulfamethoxazole, rifampin, ampicillin-sulbactam, and ampicillin resistance in B. melitensis was 36.36%, 31.82%, 27.27%, and 22.70%, respectively. Rifampin, trimethoprim-sulfamethoxazole, ampicillin, and ampicillin-sulbactam resistance was found in 35.71%, 32.14%, 32.14%, and 28.57% of B. abortus isolates, correspondingly. MBT confirmed by microfluidic electrophoresis is a successful approach for identifying Brucella species at the species level. The resistance of B. melitensis and B. abortus to various antibiotics should be investigated in future studies.


Assuntos
Brucella/genética , Brucelose/diagnóstico , Resistência Microbiana a Medicamentos/genética , Animais , Antibacterianos/farmacologia , Brucella/isolamento & purificação , Brucella/patogenicidade , Brucelose/tratamento farmacológico , Brucelose/microbiologia , Bovinos , DNA Bacteriano , Avaliação Pré-Clínica de Medicamentos/métodos , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Genótipo , Cabras , Humanos , Controle de Infecções , Proteômica/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Arábia Saudita
5.
Int J Mol Sci ; 22(24)2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34948430

RESUMO

Brucellosis is a highly prevalent zoonotic disease caused by Brucella. Brucella spp. are gram-negative facultative intracellular parasitic bacteria. Its intracellular survival and replication depend on a functional virB system, an operon encoded by VirB1-VirB12. Type IV secretion system (T4SS) encoded by the virB operon is an important virulence factor of Brucella. It can subvert cellular pathway and induce host immune response by secreting effectors, which promotes Brucella replication in host cells and induce persistent infection. Therefore, this paper summarizes the function and significance of the VirB system, focusing on the structure of the VirB system where VirB T4SS mediates biogenesis of the endoplasmic reticulum (ER)-derived replicative Brucella-containing vacuole (rBCV), the effectors of T4SS and the cellular pathways it subverts, which will help better understand the pathogenic mechanism of Brucella and provide new ideas for clinical vaccine research and development.


Assuntos
Brucella/metabolismo , Brucelose/microbiologia , Óperon , Sistemas de Secreção Tipo IV/metabolismo , Animais , Brucella/patogenicidade , Brucella/fisiologia , Interações Hospedeiro-Patógeno , Humanos , Sistemas de Secreção Tipo IV/genética , Fatores de Virulência
6.
Eur J Clin Microbiol Infect Dis ; 40(9): 1909-1917, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33837878

RESUMO

The use of matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry has proven to be rapid and accurate for the majority of clinical isolates. Some gaps remain concerning rare, emerging, or highly pathogenic species, showing the need to continuously expand the databases. In this multicenter study, we evaluated the accuracy of the VITEK MS v3.2 database in identifying 1172 unique isolates compared to identification by DNA sequence analysis. A total of 93.6% of the isolates were identified to species or group/complex level. A remaining 5.2% of the isolates were identified to the genus level. Forty tests gave a result of no identification (0.9%) and 12 tests (0.3%) gave a discordant identification compared to the reference identification. VITEK MS is also the first MALDI-TOF MS system that is able to delineate the four members of the Acinetobacter baumannii complex at species level without any specific protocol or special analysis method. These findings demonstrate that the VITEK MS v3.2 database is highly accurate for the identification of bacteria and fungi encountered in the clinical laboratory as well as emerging species like Candida auris and the highly pathogenic Brucella species.


Assuntos
Bactérias/isolamento & purificação , Brucella/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/instrumentação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/normas , Leveduras/isolamento & purificação , Bactérias/química , Bactérias/classificação , Brucella/química , Brucella/classificação , Brucella/patogenicidade , Bases de Dados Factuais/estatística & dados numéricos , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Leveduras/química , Leveduras/classificação
7.
Vet Q ; 41(1): 137-151, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33618618

RESUMO

Brucellosis not only represents an important health restraint on livestock but also causes high economic losses in many developing countries worldwide. Despite considerable efforts made for the control of brucellosis, the disease is still spreading in many regions (such as the Middle East) where it represents one of the most important health hazards impacting both animals and humans. The present review aims to investigate the efficacy of veterinary control programs regarding brucellosis, with a special focus on current prevention, control, and eradication approaches. The reasons for unsuccessful control programs such as the absence of highly effective vaccines and non-certified bulls are also debated, to understand why the prevalence of brucellosis in livestock is not decreasing in many areas despite considerable efforts taken to date. The importance of governmental and regional investment in brucellosis control remains one of the main limiting factors owing to the limited budget allocated to tackle this disease. In this context, one health concept has generated novel comprehensive approaches with multiple economic implications across the livestock industry and public health. However, the implementation of such global preventive strategies appears to be a key issue for many endemic and low-income countries. According to the collected data, epidemiological contexts including management and trade systems along with well-defined agro-ecological zones should be evaluated in brucellosis endemic countries to improve milk production and to enhance the sustainability of the livestock sector at both national and regional levels.


Assuntos
Brucelose/veterinária , Saúde Única , Zoonoses/prevenção & controle , Animais , Brucella/isolamento & purificação , Brucella/patogenicidade , Brucelose/economia , Brucelose/imunologia , Brucelose/prevenção & controle , Microbiologia de Alimentos , Humanos , Gado , Leite/microbiologia , Vacinação/veterinária , Zoonoses/microbiologia
8.
Microbiol Mol Biol Rev ; 85(1)2021 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-33568459

RESUMO

Bacteria in the genus Brucella are important human and veterinary pathogens. The abortion and infertility they cause in food animals produce economic hardships in areas where the disease has not been controlled, and human brucellosis is one of the world's most common zoonoses. Brucella strains have also been isolated from wildlife, but we know much less about the pathobiology and epidemiology of these infections than we do about brucellosis in domestic animals. The brucellae maintain predominantly an intracellular lifestyle in their mammalian hosts, and their ability to subvert the host immune response and survive and replicate in macrophages and placental trophoblasts underlies their success as pathogens. We are just beginning to understand how these bacteria evolved from a progenitor alphaproteobacterium with an environmental niche and diverged to become highly host-adapted and host-specific pathogens. Two important virulence determinants played critical roles in this evolution: (i) a type IV secretion system that secretes effector molecules into the host cell cytoplasm that direct the intracellular trafficking of the brucellae and modulate host immune responses and (ii) a lipopolysaccharide moiety which poorly stimulates host inflammatory responses. This review highlights what we presently know about how these and other virulence determinants contribute to Brucella pathogenesis. Gaining a better understanding of how the brucellae produce disease will provide us with information that can be used to design better strategies for preventing brucellosis in animals and for preventing and treating this disease in humans.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Brucella/patogenicidade , Brucelose/patologia , Lipopolissacarídeos/imunologia , Sistemas de Secreção Tipo IV/metabolismo , Adaptação Fisiológica , Animais , Proteínas da Membrana Bacteriana Externa/genética , Brucella/genética , Brucella/imunologia , Feminino , Especificidade de Hospedeiro/genética , Humanos , Macrófagos/microbiologia , Gravidez , Complicações Infecciosas na Gravidez/microbiologia , Complicações Infecciosas na Gravidez/patologia , Trofoblastos/microbiologia , Sistemas de Secreção Tipo IV/genética , Virulência , Fatores de Virulência
9.
FEMS Microbiol Rev ; 45(1)2021 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-33016322

RESUMO

The genus Brucella, described by Meyer and Shaw in 1920, comprises bacterial pathogens of veterinary and public health relevance. For 36 years, the genus came to include three species that caused brucellosis in livestock and humans. In the second half of the 20th century, bacteriologists discovered five new species and several 'atypical' strains in domestic animals and wildlife. In 1990, the Brucella species were recognized as part of the Class Alphaproteobacteria, clustering with pathogens and endosymbionts of animals and plants such as Bartonella, Agrobacterium and Ochrobactrum; all bacteria that live in close association with eukaryotic cells. Comparisons with Alphaproteobacteria contributed to identify virulence factors and to establish evolutionary relationships. Brucella members have two circular chromosomes, are devoid of plasmids, and display close genetic relatedness. A proposal, asserting that all brucellae belong to a single species with several subspecies debated for over 70 years, was ultimately rejected in 2006 by the subcommittee of taxonomy, based on scientific, practical, and biosafety considerations. Following this, the nomenclature of having multiples Brucella species prevailed and defined according to their molecular characteristics, host preference, and virulence. The 100-year history of the genus corresponds to the chronicle of scientific efforts and the struggle for understanding brucellosis.


Assuntos
Brucella/classificação , Brucelose/microbiologia , Animais , Brucella/genética , Brucella/patogenicidade , Especificidade de Hospedeiro , Humanos , Terminologia como Assunto , Fatores de Virulência/genética
10.
PLoS One ; 15(11): e0238212, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33201876

RESUMO

Bovine brucellosis is an infectious bacterial disease caused by members of genus Brucella, affecting both animals and humans, and resulting in a serious economic loss in animal production sector and deterioration of public health. A cross-sectional study was conducted from November 2014 to April 2015 to determine the seroprevalence and associated risk factors of bovine brucellosis in Sendafa, Oromia Special Zone, Ethiopia. A total of 503 blood samples were collected using a simple random sampling technique from dairy cattle of above 6 months of age with no history of previous vaccination against brucellosis. All sera samples were subjected to both Rose Bengal Plate Test for screening and Complement Fixation Test for confirmation. Accordingly, the overall seroprevalence of bovine brucellosis in the study area was 0.40%. The result showed that the seroprevalence of bovine brucellosis in the study area was not statistically significant with all proposed risk factors. No reactors were observed in male animals. The seroprevalence was observed in animals without previous history of abortion. Moreover, information was gathered on individual animal and farm-level risk factors and other farm characteristics using a questionnaire. Awareness among society was poor, so the positive animals can be a potential hazard to animals and humans in the study area. Therefore, public education should be done to improve the awareness of the community on bovine brucellosis and its public health impact with due consideration on the safe consumption of food of animal origin.


Assuntos
Brucelose Bovina/epidemiologia , Brucelose Bovina/etiologia , Animais , Brucella/patogenicidade , Brucelose Bovina/microbiologia , Bovinos , Estudos Transversais , Indústria de Laticínios , Ensaio de Imunoadsorção Enzimática/métodos , Etiópia , Feminino , Masculino , Prevalência , Fatores de Risco , Estudos Soroepidemiológicos , Inquéritos e Questionários
12.
Int J Mol Sci ; 21(20)2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33092044

RESUMO

Brucella organisms are responsible for one of the most widespread bacterial zoonoses, named brucellosis. The disease affects several species of animals, including humans. One of the most intriguing aspects of the brucellae is that the various species show a ~97% similarity at the genome level. Still, the distinct Brucella species display different host preferences, zoonotic risk, and virulence. After 133 years of research, there are many aspects of the Brucella biology that remain poorly understood, such as host adaptation and virulence mechanisms. A strategy to understand these characteristics focuses on the relationship between the genomic diversity and host preference of the various Brucella species. Pseudogenization, genome reduction, single nucleotide polymorphism variation, number of tandem repeats, and mobile genetic elements are unveiled markers for host adaptation and virulence. Understanding the mechanisms of genome variability in the Brucella genus is relevant to comprehend the emergence of pathogens.


Assuntos
Brucella/genética , Brucelose/diagnóstico , Genoma Bacteriano/genética , Genômica/métodos , Animais , Brucella/classificação , Brucella/patogenicidade , Brucelose/microbiologia , Evolução Molecular , Humanos , Filogenia , Polimorfismo de Nucleotídeo Único , Virulência/genética
13.
Front Immunol ; 11: 1944, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32983124

RESUMO

Bovine brucellosis, cause by infection with Brucella abortus, causes reproductive failure in cattle, has a major economic impact to producers, and as a zoonoses, it is a disease of public health concern. Characterization of the protective immune response against Brucella infection is important to our understanding of disease pathogenesis and for the development of diagnostic assays and vaccines. Most of the knowledge regarding protection against Brucella comes from studies in the murine model, but less is known about the immune responses in cattle. Assessment of antigen-specific T cell frequency and functional phenotype are critical to understand the immune status of the host, characterize mechanisms of protective immunity and immunopathology, and to predict immune protection. The frequency of circulating T cells specific for a particular pathogen is often very low, making analysis of such responses difficult. Our goal was to develop a flow-cytometry based approach to better track Brucella-specific T cell responses. Using peripheral blood mononuclear cells (PMBC) from Brucella abortus strain RB51-vaccinated cattle, we optimized an in vitro stimulation protocol based on a combination of antigen and pan-T cell stimulation. We then assessed RB51-specific T cell responses by concurrently measuring proliferation and cytokine production using flow-cytometry. This methodology enhances the detection of peripheral, Brucella-specific responses in cattle following RB51 vaccination. This protocol is versatile in that it can be modified to fit other in vitro stimulation systems and additional functional or phenotypic parameters can be added for flow cytometric detection and characterization of antigen-specific T cells.


Assuntos
Vacina contra Brucelose/administração & dosagem , Brucella/patogenicidade , Brucelose Bovina/prevenção & controle , Linfócitos T CD4-Positivos/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Imunogenicidade da Vacina , Ativação Linfocitária/efeitos dos fármacos , Animais , Brucella/imunologia , Vacina contra Brucelose/imunologia , Brucelose Bovina/imunologia , Brucelose Bovina/metabolismo , Brucelose Bovina/microbiologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/microbiologia , Bovinos , Células Cultivadas , Feminino , Citometria de Fluxo , Interações Hospedeiro-Patógeno , Imunoensaio , Interferon gama/metabolismo , Fatores de Tempo , Vacinação
14.
J Int Med Res ; 48(6): 300060520924548, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32552113

RESUMO

OBJECTIVE: We aimed to describe the clinical characteristics and prognosis of 22 patients with Brucella-induced reproductive system injury. METHODS: We assessed 22 patients with reproductive system injury between 2010 and 2018 at The First Affiliated Hospital of Xinjiang Medical University. RESULTS: The disease is predominant in men. Male patients had orchitis, erectile dysfunction, prostatitis, and urethral stricture, while female patients had vaginitis and cervicitis. Some patients had laboratory abnormalities and liver injury. Patients received combination therapy of rifampicin and doxycycline. Doxycycline combined with levofloxacin or moxifloxacin was administered to patients with rifampicin intolerance. All patients had received antibiotic therapy for at least 6 weeks. One patient was lost to follow-up, one patient relapsed because of osteoarthropathy, and one patient had dysuria resulting from chronic prostatitis. The clinical symptoms resolved in the other patients, and the overall patient prognosis was good. CONCLUSION: Clinicians should pay attention to brucellosis-induced reproductive system damage. The two-drug regimen of rifampicin+doxycycline is recommended for these patients. Doxycycline combined with levofloxacin or moxifloxacin should be used in patients with brucellosis-induced reproductive system damage who have rifampicin intolerance. The treatment course should be at least 6 weeks.


Assuntos
Brucella/patogenicidade , Genitália/lesões , Genitália/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Brucelose/epidemiologia , China , Doxiciclina/uso terapêutico , Quimioterapia Combinada/métodos , Feminino , Humanos , Levofloxacino/uso terapêutico , Masculino , Pessoa de Meia-Idade , Moxifloxacina/uso terapêutico , Estudos Retrospectivos , Rifampina/uso terapêutico
15.
Microbes Infect ; 22(9): 407-415, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32535086

RESUMO

Brucella infection is frequently acquired through the respiratory route. The pathogen disseminates systemically from the lungs to infect peripheral organs. In this review we summarize the existing data on the pathogenesis of inhalational Brucella infection, the pulmonary immune response to the pathogen, and potential strategies for inducing protective lung immunity.


Assuntos
Brucelose/imunologia , Imunidade , Pulmão/imunologia , Animais , Brucella/imunologia , Brucella/patogenicidade , Vacina contra Brucelose/imunologia , Humanos , Vacinação , Virulência/imunologia
16.
J Clin Neurosci ; 78: 360-364, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32418812

RESUMO

Brucellar spondylodiscitis (BS) is the most common form of musculoskeletal brucellosis. The isolation of Brucella spp from blood, other body fluids or tissue cultures is the gold standard for definitive diagnosis of BS. BS shows a large histopathological spectrum of lesions with non-specific and granulomatous forms, and its histopathological features are not widely reported. This case series study reported the histopathological features of a series of 21 BS. Ten cases revealed nonspecific forms of BS. Lymphocytes were the predominant inflammatory cells in this group. In one case neutrophils were predominant. The eleven remaining were granulomatous. The 11 exhibited histiocytic type granulomas. Ten were non-necrotizing. One case, taken from abscess wall, contained minimal deposition of caseous like necrotic material. This case and 2 others corresponding to abscess wall biopsies, showed histiocytic granulomas mixed with small aggregates of epithelioid cells without well-formed epithelioid granuloma nor giant cell. The histopathological diagnosis of BS is challenging. Nonspecific forms of BS, mimiking pyogenic spondylodiscitis, are observed in about half of the cases. Although nonspecific forms of BS are characterized by the predominance of lymphocytes and plasmocytes, BS forms with predominant neutrophil cell infiltration do exist. Histiocytic granuloma is highly suggestive of BS. Purely epithelioid forms of BS were not observed in the present series. Caseous like necrosis suggestive of tuberculosis is a possible feature of BS.


Assuntos
Brucelose/complicações , Discite/microbiologia , Brucella/patogenicidade , Brucelose/diagnóstico , Brucelose/patologia , Discite/etiologia , Discite/patologia , Feminino , Granuloma/patologia , Humanos , Linfócitos/patologia , Masculino , Necrose , Neutrófilos/patologia , Tuberculose
17.
Rev. cuba. invest. bioméd ; 39(1): e336, ene.-mar. 2020. graf
Artigo em Espanhol | CUMED, LILACS | ID: biblio-1126572

RESUMO

Introducción: El género Brucella está incluido en la familia Brucellaceae que pertenece al orden Rhizobiales y es reconocido por su alto grado de patogenicidad. Las bacterias de este género son responsables de la brucelosis, enfermedad que ha sido reportada como una de las zoonosis más importantes a nivel mundial por su incidencia en el ganado y el hombre. Los estudios previos para la clasificación taxonómica del género, se han basado fundamentalmente en el análisis del gen 16S ARNr. Sin embargo, pocas investigaciones se han dirigido a la identificación de marcadores moleculares que distingan a sus miembros de otros grupos de bacterias. Objetivo: Identificar inserciones en secuencias de proteínas conservadas, que pudieran ser utilizados como marcadores moleculares para la taxonomía y diagnóstico de especies del género Brucella. Métodos: Las secuencias homólogas de las proteínas analizadas fueron obtenidas de bases de datos internacionales y, posteriormente, alineadas con el programa ClustalX2, para ello fueron considerados los parámetros sugeridos en la literatura. Resultados: Se identificaron inserciones en las proteínas oxoglutarato deshidrogenasa (componente E1) y ADN ligasa A específicas del género Brucella. Conclusiones: Las inserciones halladas pueden ser empleadas como complemento a los métodos tradicionales de clasificación taxonómica y para el diagnóstico molecular de bacterias incluidas en el género Brucella(AU)


Introduction: Brucella is a genus from the Brucellaceae family, Rhizobiales order. This genus is recognized for its high pathogenicity. Brucella bacteria cause brucellosis, a disease reported as one of the most important zoonoses worldwide due to its incidence in cattle and people. Previous studies on taxonomic classification of the genus have been mainly based on the analysis of gene 16S rDNA. However, few studies have been aimed at identification of molecular markers distinguishing its members from other groups of bacteria. Objective: Identify insertions in preserved protein sequences which could be used as molecular markers for the taxonomy and diagnosis of species from the Brucella genus. Methods: The homologous sequences for the proteins analyzed were obtained from international databases and aligned with the software ClustalX2, considering the parameters suggested in the literature. Results: Insertions were identified in the proteins oxoglutarate dehydrogenase (component E1) and DNA ligase A, specific of the genus Brucella. Conclusions: The insertions found may be used as complements to the traditional methods for taxonomic classification and for the molecular diagnosis of bacteria from the genus Brucella(AU)


Assuntos
Humanos , Homologia de Sequência , Complexo Cetoglutarato Desidrogenase , Brucella/patogenicidade , Marcadores Genéticos/genética
18.
Folia Microbiol (Praha) ; 65(1): 1-16, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30783994

RESUMO

As dendritic cells (DCs) are among the first cells to encounter antigens, these cells trigger both innate and T cell responses, and are the most potent antigen-presenting cells. Brucella spp., which is an intracellular facultative and stealthy pathogen, is able to evade the bactericidal activities of professional phagocytes. Several studies have demonstrated that Brucella can survive and replicate intracellularly, thereby provoking impaired maturation of DCs. Therefore, the interaction between DCs and Brucella becomes an interesting model to study the immune response. In this review, we first will describe the most common techniques for DCs differentiation in vitro as well as general features of brucellosis. Then, the interaction of DCs and Brucella, including pathogen recognition, molecular mechanisms of bacterial pathogenesis, and intracellular trafficking of Brucella to subvert innate response, will be reviewed. Finally, we will debate diversity in immunological DC response and the controversial role of DC activation against Brucella infection.


Assuntos
Brucella/imunologia , Brucella/patogenicidade , Brucelose/imunologia , Células Dendríticas/microbiologia , Interações Hospedeiro-Patógeno/imunologia , Animais , Citoplasma/microbiologia , Humanos , Camundongos
19.
Virulence ; 10(1): 868-878, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31635539

RESUMO

Brucella microti was isolated a decade ago from wildlife and soil in Europe. Compared to the classical Brucella species, it exhibits atypical virulence properties such as increased growth in human and murine macrophages and lethality in experimentally infected mice. A spontaneous rough (R) mutant strain, derived from the smooth reference strain CCM4915T, showed increased macrophage colonization and was non-lethal in murine infections. Whole-genome sequencing and construction of an isogenic mutant of B. microti and Brucella suis 1330 revealed that the R-phenotype was due to a deletion in a single gene, namely wbkE (BMI_I539), encoding a putative glycosyltransferase involved in lipopolysaccharide (LPS) O-polysaccharide biosynthesis. Complementation of the R-strains with the wbkE gene restored the smooth phenotype and the ability of B. microti to kill infected mice. LPS with an intact O-polysaccharide is therefore essential for lethal B. microti infections in the murine model, demonstrating its importance in pathogenesis.


Assuntos
Proteínas de Bactérias/genética , Brucella/genética , Brucella/patogenicidade , Brucelose/microbiologia , Glicosiltransferases/genética , Polissacarídeos Bacterianos/biossíntese , Animais , Brucella/enzimologia , Modelos Animais de Doenças , Feminino , Genótipo , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Mutação , Fenótipo , Virulência
20.
Molecules ; 24(17)2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31470504

RESUMO

Brucellosis, also known as "undulant fever" is a zoonotic disease caused by Brucella, which is a facultative intracellular bacterium. Despite efforts to eradicate this disease, infection in uncontrolled domestic animals persists in several countries and therefore transmission to humans is common. Brucella evasion of the innate immune system depends on its ability to evade the mechanisms of intracellular death in phagocytic cells. The BvrR-BvrS two-component system allows the bacterium to detect adverse conditions in the environment. The BvrS protein has been associated with genes of virulence factors, metabolism, and membrane transport. In this study, we predicted the DNA sequence recognized by BvrR with Gibbs Recursive Sampling and identified the three-dimensional structure of BvrR using I-TASSER suite, and the interaction mechanism between BvrR and DNA with Protein-DNA docking and molecular dynamics (MD) simulation. Based on the Gibbs recursive Sampling analysis, we found the motif AAHTGC (H represents A, C, and T nucleotides) as a possible sequence recognized by BvrR. The docking and EMD simulation results showed that C-terminal effector domain of BvrR protein is likely to interact with AAHTGC sequence. In conclusion, we predicted the structure, recognition motif, and interaction of BvrR with DNA.


Assuntos
Proteínas de Bactérias/química , Brucella/química , DNA/química , Fatores de Virulência/química , Motivos de Aminoácidos , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Brucella/patogenicidade , DNA/metabolismo , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Motivos de Nucleotídeos , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Homologia Estrutural de Proteína , Termodinâmica , Fatores de Virulência/metabolismo
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