RESUMO
BACKGROUND: Assessments, such as summative structured examinations, aim to verify whether students have acquired the necessary competencies. It is important to familiarize students with the examination format prior to the assessment to ensure that true competency is measured. However, it is unclear whether students can demonstrate their true potential or possibly perform less effectively due to the unfamiliar examination format. Hence, we questioned whether a 10-min active familiarization in the form of simulation improved medical students´ OSCE performance. Next, we wanted to elucidate whether the effect depends on whether the familiarization procedure is active or passive. METHODS: We implemented an intervention consisting of a 10-min active simulation to prepare the students for the OSCE setting. We compared the impact of this intervention on performance to no intervention in 5th-year medical students (n = 1284) from 2018 until 2022. Recently, a passive lecture, in which the OSCE setting is explained without active participation of the students, was introduced as a comparator group. Students who participated in neither the intervention nor the passive lecture group formed the control group. The OSCE performance between the groups and the impact of gender was assessed using X2, nonparametric tests and regression analysis (total n = 362). RESULTS: We found that active familiarization of students (n = 188) yields significantly better performance compared to the passive comparator (Cohen´s d = 0.857, p < 0.001, n = 52) and control group (Cohen´s d = 0.473, p < 0.001, n = 122). In multivariate regression analysis, active intervention remained the only significant variable with a 2.945-fold increase in the probability of passing the exam (p = 0.018). CONCLUSIONS: A short 10-min active intervention to familiarize students with the OSCE setting significantly improved student performance. We suggest that curricula should include simulations on the exam setting in addition to courses that increase knowledge or skills to mitigate the negative effect of nonfamiliarity with the OSCE exam setting on the students.
Assuntos
Educação de Graduação em Medicina , Estudantes de Medicina , Humanos , Avaliação Educacional/métodos , Educação de Graduação em Medicina/métodos , Competência Clínica , Exame FísicoRESUMO
The autoimmune renal disease deficient for complement factor H-related (CFHR) genes and autoantibody-positive form of hemolytic uremic syndrome is characterized by the presence of autoantibodies specific for the central complement regulator, factor H, combined with a homozygous deficiency, mostly in CFHR3 and CFHR1 Because FHR3 and FHR1 bind to C3d and inactivated C3b, which are ligands for complement receptor type 2 (CR2/CD21), the aim of the current study was to examine whether FHR3-C3d or FHR1-C3d complexes modulate B cell activation. Laser-scanning microscopy and automated image-based analysis showed that FHR3, but not FHR1 or factor H, blocked B cell activation by the BCR coreceptor complex (CD19/CD21/CD81). FHR3 bound to C3d, thereby inhibiting the interaction between C3d and CD21 and preventing colocalization of the coreceptor complex with the BCR. FHR3 neutralized the adjuvant effect of C3d on B cells, as shown by inhibited intracellular CD19 and Akt phosphorylation in Raji cells, as well as Ca(2+) release in peripheral B cells. In cases of CFHR3/CFHR1 deficiency, the FHR3 binding sites on C3d are occupied by factor H, which lacks B cell-inhibitory functions. These data provide evidence that FHR3, which is absent in patients with the autoimmune form of hemolytic uremic syndrome, is involved in B cell regulation.
Assuntos
Linfócitos B/imunologia , Proteínas Sanguíneas/imunologia , Complemento C3d/imunologia , Síndrome Hemolítico-Urêmica/imunologia , Ativação Linfocitária/imunologia , Separação Celular , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Humanos , Processamento de Imagem Assistida por Computador , Microscopia ConfocalRESUMO
To estimate the prevalence of bovine tuberculosis in the Alpine region, we studied the epidemiology of Mycobacterium caprae in wildlife during the 2009-2012 hunting seasons. Free-ranging red deer (Cervus elaphus) were a maintenance host in a hot-spot area, mainly located in Austria.
Assuntos
Cervos/microbiologia , Reservatórios de Doenças/microbiologia , Mycobacterium bovis , Tuberculose Bovina/epidemiologia , Tuberculose Bovina/transmissão , Animais , Animais Selvagens , Áustria , Bovinos , Feminino , Geografia , Alemanha , Itália , Masculino , Tipagem Molecular , Mycobacterium bovis/classificação , Mycobacterium bovis/genética , Prevalência , SuíçaRESUMO
The lack of complete genome sequence information for Mycobacterium caprae complicates a robust differentiation of M. caprae and Mycobacterium bovis. In this study, the presence or absence of M. caprae-specific single nucleotide polymorphisms in lepA and gyrB genes was assessed. The region of difference 4 (RD4) was analyzed for the identification and characterization of M. caprae. Molecular characteristics were evaluated in 12 recent M. caprae isolates from livestock and wildlife collected over a 3-year period in Bavaria, Germany. Conventional PCR strategies, sequence analysis of PCR fragments, and data from a next-generation sequencing approach together with variable-number tandem-repeat genotyping were utilized. Single nucleotide polymorphisms in the lepA and gyrB genes indicating the presence of M. caprae were detected in all the isolates. At least three different RD4 variants were found for Alpine M. caprae isolates. The results demonstrate that the RD4 region is rather heterogeneous in M. caprae genomes. As assumed by others, the presence of RD4 is critical for PCR-based differentiation of M. caprae from M. bovis, but in addition, the observed variability of RD4 allows the identification of M. caprae genotypes and may be indicative of a geographical-type appearance.
Assuntos
DNA Girase/genética , Mycobacterium , Fatores de Elongação da Transcrição/genética , Animais , Técnicas de Tipagem Bacteriana , Sequência de Bases , DNA Bacteriano/análise , Variação Genética , Genoma Bacteriano/genética , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Repetições Minissatélites/genética , Dados de Sequência Molecular , Tipagem Molecular , Mycobacterium/classificação , Mycobacterium/genética , Mycobacterium/isolamento & purificação , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNARESUMO
BACKGROUND: The Austrian State medical universities had to change their admission system in 2005. Until this year admission to medical studies was unrestricted. Innsbruck Medical University chose the Eignungstest für das Medizinstudium in der Schweiz (EMS) aptitude test for admission testing. AIMS AND OBJECTIVES: Did the implementation of a selection process affect the academic performance and drop-out rates of students according to gender? METHODS: Two groups of students were compared: 'open admission' (2002-2004), and 'selected' (2006-2009). Academic performance was tested according to results in the final exams after year 1 (SIP 1; SIP, summative integrierte Prüfung) and after year 3 (SIP 3). Drop-out rates were recorded using the registration system of the university. RESULTS: Both, male and female 'selected' students had a higher passing rate regarding SIP 1 and they passed SIP 1 in shorter time and using fewer attempts than the open admission group. The percentage in passing SIP 3 did not change due to change in admission. The drop-out rates were significantly reduced for male and female students. 'Unselected' female students had a significantly higher drop-out ratio than 'unselected' male counterparts. After EMS testing, the drop-out ratios of female and male students were not significantly different. CONCLUSION: Selected applicants were more able and better motivated to study medicine.
Assuntos
Critérios de Admissão Escolar/estatística & dados numéricos , Faculdades de Medicina/estatística & dados numéricos , Evasão Escolar/estatística & dados numéricos , Estudantes de Medicina/estatística & dados numéricos , Áustria , Avaliação Educacional , Feminino , Humanos , Masculino , Fatores SexuaisRESUMO
Aim: The Austrian Competence Level Catalogue for Medical Skills clearly states the importance of teaching communicative and social competence in the different subject areas of undergraduate medical and dental education. This paper aims to present an overview of the academic courses at the Medical University of Innsbruck that explicitly address the promotion of communication and social skills in medical students. Method: This paper focuses on educators' descriptions of how communicating with patients is taught. The Medical University's longitudinal curriculum on medical interviewing is presented in detail. The courses on ethical principles in the dissection course, palliative medicine, and gender medicine are also outlined as examples. In addition, lecturers (n=536) participated in an online survey to determine the teaching and testing content regarding patient communication and to measure the value attached to the associated teaching and learning methods. Results: The examples given by educators to illustrate learning objectives, educational content, and the teaching methods used to impart communicative and social competence provide an overview of the courses which focus on this topic or intentionally address it during the course. The results of the online survey offer a broad overview of the awareness of the topic at the university. Different testing formats are used to assess the skills being taught. Conclusion: Familiarity with the various teaching methods used in the different courses is important for developing communicative and social competence in medical education. Active networking is necessary to anchor communicative and social competency as a major thread throughout an entire medical curriculum.
Assuntos
Comunicação , Currículo , Educação Médica , Habilidades Sociais , Áustria , Competência Clínica , Educação Médica/organização & administração , Humanos , Estudantes de MedicinaRESUMO
While our previous studies have demonstrated that complement activation induced by complement receptors type 2 (CR2/CD21) and 1 (CR1/CD35) results in C3-fragment deposition and membrane attack complex (MAC) formation in human B cells, the consequences of these events for B-cell functions remain unknown. In the present study, we show that CR2-induced complement activation results in membrane depolarization, as indicated by annexin V binding, with kinetics similar to those of C3-fragment deposition and different from those of MAC formation. On the other hand, like MAC formation, depolarization requires activation of complement via the alternative pathway, as indicated by total inhibition upon neutralization of factor D, and is abrogated by combined blockade of CR1 and CR2, but not of either receptor alone. The membrane depolarization is not associated with the apoptosis of B cells, as examined by co-staining with APO-2.7 or by the TdT-mediated biotin-dUTP nick-end labelling (TUNEL) assay. Confocal microscopy revealed that depolarization and C3 deposition, unlike MAC deposition, are limited to restricted areas on the B-cell surface. Double staining revealed a close association between the C3-fragment patches and membrane depolarization, as well as redistribution of lipid rafts to these areas. We propose that these events may play a role in the regulation of B-cell signalling and cross-talk with T cells.
Assuntos
Linfócitos B/imunologia , Ativação do Complemento , Complemento C3/metabolismo , Microdomínios da Membrana/imunologia , Receptores de Complemento 3d/metabolismo , Anexina A5/imunologia , Anexina A5/metabolismo , Anticorpos Monoclonais/imunologia , Apoptose/efeitos dos fármacos , Apoptose/imunologia , Linfócitos B/efeitos dos fármacos , Fator D do Complemento/antagonistas & inibidores , Fator D do Complemento/metabolismo , Complexo de Ataque à Membrana do Sistema Complemento/imunologia , Complexo de Ataque à Membrana do Sistema Complemento/metabolismo , Via Alternativa do Complemento , Ácido Edético/farmacologia , Humanos , Fosfatidilserinas/imunologia , Fosfatidilserinas/metabolismo , Receptores de Complemento/antagonistas & inibidores , Receptores de Complemento/metabolismo , Receptores de Complemento 3d/antagonistas & inibidoresRESUMO
Genotyping has become an indispensable tool in medical microbiology and epidemiology. One of the first targets has been Mycobacterium tuberculosis. Over the past 15 years approximately 900 pertinent publications have substantiated the value of the genotyping approach for tuberculosis control. New insights into the understanding of the natural history of tuberculosis, especially regarding the frequencies of reactivation, reinfection or multiple infection entailed adaptations of pathophysiological concepts. However, assessment of recent transmission, outbreak analysis, and detection of laboratory contamination still form the genuine scope of genotyping. Detection of unsuspected clusters of cases can provide clues to search for further, undetected cases. Uncovering false positive cultures spares the risks and costs of unnecessary treatment and may reveal systematic laboratory weaknesses. Several European countries already profit from nationwide prospective fingerprinting. After providing genotyping results to public health officials, these were able to document epidemiological links for substantially more tuberculosis patients. On a global scale, strain families and particular strains have been identified, characterised and traced in their spread. The importation of Beijing-genotype multidrug-resistant M. tuberculosis into Central European countries will be described here as an example. The goal for further developments is the ability to compare isolates for epidemiological purposes in a single step that also comprises species determination, drug resistance testing and detection of pathogenicity factors.
Assuntos
Métodos Epidemiológicos , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/genética , Vigilância da População/métodos , Medição de Risco/métodos , Tuberculose/epidemiologia , Tuberculose/microbiologia , Europa (Continente)/epidemiologia , Humanos , Técnicas Microbiológicas , Mycobacterium tuberculosis/isolamento & purificação , Prevalência , Fatores de RiscoRESUMO
BACKGROUND: The Direct Repeat locus of the Mycobacterium tuberculosis complex (MTC) is a member of the CRISPR (Clustered regularly interspaced short palindromic repeats) sequences family. Spoligotyping is the widely used PCR-based reverse-hybridization blotting technique that assays the genetic diversity of this locus and is useful both for clinical laboratory, molecular epidemiology, evolutionary and population genetics. It is easy, robust, cheap, and produces highly diverse portable numerical results, as the result of the combination of (1) Unique Events Polymorphism (UEP) (2) Insertion-Sequence-mediated genetic recombination. Genetic convergence, although rare, was also previously demonstrated. Three previous international spoligotype databases had partly revealed the global and local geographical structures of MTC bacilli populations, however, there was a need for the release of a new, more representative and extended, international spoligotyping database. RESULTS: The fourth international spoligotyping database, SpolDB4, describes 1939 shared-types (STs) representative of a total of 39,295 strains from 122 countries, which are tentatively classified into 62 clades/lineages using a mixed expert-based and bioinformatical approach. The SpolDB4 update adds 26 new potentially phylogeographically-specific MTC genotype families. It provides a clearer picture of the current MTC genomes diversity as well as on the relationships between the genetic attributes investigated (spoligotypes) and the infra-species classification and evolutionary history of the species. Indeed, an independent Naïve-Bayes mixture-model analysis has validated main of the previous supervised SpolDB3 classification results, confirming the usefulness of both supervised and unsupervised models as an approach to understand MTC population structure. Updated results on the epidemiological status of spoligotypes, as well as genetic prevalence maps on six main lineages are also shown. Our results suggests the existence of fine geographical genetic clines within MTC populations, that could mirror the passed and present Homo sapiens sapiens demographical and mycobacterial co-evolutionary history whose structure could be further reconstructed and modelled, thereby providing a large-scale conceptual framework of the global TB Epidemiologic Network. CONCLUSION: Our results broaden the knowledge of the global phylogeography of the MTC complex. SpolDB4 should be a very useful tool to better define the identity of a given MTC clinical isolate, and to better analyze the links between its current spreading and previous evolutionary history. The building and mining of extended MTC polymorphic genetic databases is in progress.
Assuntos
Bases de Dados Factuais , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/genética , Polimorfismo Genético , Tuberculose/epidemiologia , Biologia Computacional , Genética Populacional , Mycobacterium tuberculosis/isolamento & purificação , Filogenia , SorotipagemRESUMO
OBJECTIVES: To compare M. tuberculosis complex genotypes from representative regions of the Czech Republic in order to estimate changes in strain prevalence and in the extent of imported drug-resistant tuberculosis. METHODS: Primary M. tuberculosis complex isolates (n=155) and follow-up isolates (n=15) from 155 patients from the first half of 2004 (98 from Prague, 37 from South Moravia and 35 from the Moravian-Silesian region) were genotyped by IS6110-RFLP, spoligotyping, and partly by VNTR-genotyping. RESULTS: Based on IS6110-RFLP, 110 of 155 (71%) primary isolates were unique. Forty-five isolates (29%) were found in 15 clusters comprising two to six patients and all but one cluster were also discriminated by MIRU-VNTR-genotyping. Four clusters comprised patients from different regions, and six were ongoing for several years. An indication of MDR-strain transmission was found in one instance. All four Beijing-type isolates with any resistance were associated with immigration from Eastern Europe. CONCLUSIONS: The molecular epidemiological data of this period-prevalence, population based study and its comparison to earlier investigations point to a low extent of clustering between M. tuberculosis complex isolates in representative regions of the Czech Republic. Few clusters extending geographically and/or over several years were identified, providing a means for an in-depth analysis of risk factors of transmission. Beijing genotype isolates were shown to increase in prevalence to reach 6.5%. Drug resistant isolates of this genotype were associated with immigration of from Eastern Europe, although direct transmission of a resistant isolate was probable only in one of eleven cases.
Assuntos
Mycobacterium tuberculosis/genética , Tuberculose/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , República Tcheca/epidemiologia , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Mycobacterium tuberculosis/isolamento & purificação , Prevalência , Tuberculose/genéticaRESUMO
Mycobacterium caprae, a member of the Mycobacterium tuberculosis complex, causes tuberculosis (TB) in man and animals. Some features distinguish M. caprae from its epidemiological twin, Mycobacterium bovis: M. caprae is evolutionarily older, accounts for a smaller burden of zoonotic TB and is not globally distributed, but primarily restricted to European countries. M. caprae occurs only in a low proportion of human TB cases and this proportion may even decrease, if progress toward eradication of animal TB in Europe continues. So why bother, if M. caprae is not an enigma for diagnostic TB tests and if resistance against first-line drugs is a rarity with M. caprae? This 'European' pathogen of zoonotic TB asks interesting questions regarding the definition of a species. The latter, seemingly only an academic question, particularly requires and challenges the collaboration between human and veterinary medicine.
Assuntos
Mycobacterium/fisiologia , Tuberculose/epidemiologia , Tuberculose/microbiologia , Animais , Europa (Continente) , Genótipo , Humanos , Mycobacterium/genética , Publicações Periódicas como Assunto , Fatores de Risco , Tuberculose/tratamento farmacológicoAssuntos
Amazona/microbiologia , Doenças das Aves/transmissão , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/transmissão , Tuberculose/veterinária , Zoonoses , Animais , Técnicas de Tipagem Bacteriana/veterinária , Doenças das Aves/epidemiologia , Evolução Fatal , Feminino , Humanos , Mycobacterium tuberculosis/patogenicidade , Tuberculose/epidemiologiaRESUMO
A survey of 143 hunter-harvested red deer for tuberculosis was conducted in an Alpine area in Western Austria over two subsequent years. There, single tuberculosis cases caused by Mycobacterium caprae had been detected in cattle and red deer over the preceding decade. The area under investigation covered approximately 500 km(2), divided into five different hunting plots. Lymph nodes of red deer were examined grossly and microscopically for typical tuberculosis-like lesions and additionally by microbiological culturing. Executing a detailed hunting plan, nine M. caprae isolates were obtained. Six out of nine originated from one single hunting plot with the highest estimated prevalence of tuberculosis, that is, 23.1%. All isolates were genotyped by mycobacterial interspersed repetitive unit-variable number of tandem repeat (MIRU-VNTR) typing of 24 standard loci plus VNTR 1982. All nine isolates belonged to a single cluster termed "Lechtal" which had been found in cattle and red deer in the region, demonstrating a remarkable dominance and stability over ten years. This is the first report on a systematic prospective study investigating the prevalence and strain variability of M. caprae infection in red deer in Austria and in the Alpine countries.
RESUMO
Cancer targeting with peptides has become promising with the emergence of combinatorial peptide techniques such as phage display. Using phage display under stringent screening conditions, we selected five distinct peptides that specifically recognized the CD21 receptor, a cell surface marker of malignant B cell lymphoma. Two highly hydrophobic sequences were excluded (RLAYWCFSGLFLLVC and PVAAVSFVPYLVKTY). The binding affinity toward CD21 of the other three selected peptides (RMWPSSTVNLSAGRR, PNLDFSPTCSFRFGC, and GRVPSMFGGHFFFSR) was analyzed with fluorescence quenching. Their dissociation constants were determined to be within the micromolar range. On the basis of the results of phage ELISA, competitive phage ELISA, and fluorescence quenching, the binding sites of the three selected peptides were found to reside within the first four short consensus repeats of CD21 (SCR1-4). The peptide RMWPSSTVNLSAGRR (P1) was bound to the N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer, a potential drug carrier for chemotherapeutic agents, and the surface binding properties of HPMA copolymer-P1 conjugates were investigated. Specific interactions were observed between HPMA copolymer-P1 conjugates and surface-bound receptor. Binding of HPMA copolymer-P1 conjugates was directly related to the amount of surface (MaxiSorp plate) bound receptor, and the binding of the conjugates could be inhibited by the application of a 3-4 orders-of-magnitude excess of free peptide over the peptide concentration in conjugates. The enhanced binding of polymer-bound peptide was ascribed to multivalent interactions between the HPMA copolymer-P1 conjugate and the surface-bound CD21 receptor.
Assuntos
Metacrilatos/química , Biblioteca de Peptídeos , Peptídeos/química , Peptídeos/metabolismo , Receptores de Complemento 3d/metabolismo , Sequência de Aminoácidos , Ensaio de Imunoadsorção Enzimática , Ligantes , Metacrilatos/metabolismo , Dados de Sequência Molecular , Estrutura Molecular , Peptídeos/genética , Ligação Proteica , Receptores de Complemento 3d/genéticaRESUMO
Using the one-bead one-compound (OBOC) combinatorial method, four heptapeptide ligands of CD21 receptor, a cell surface marker of malignant B cell lymphoma, were identified with an innovative two-step fluorescence screening method to overcome the limitation caused by autofluorescence of TentaGel resin. The binding affinities of selected peptides, YILIHRN (B1), PTLDPLP (B2), and LVLLTRE (B3), were in the micromolar region as determined by a fluorescence quenching assay. Peptide B1 was conjugated to N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer via spacers of different lengths, composed of one to four repeats of the 8-amino-3,6-dioxaoctanoic acid (A) group. The evaluation of the biorecognizability of HPMA copolymer-B1 conjugates by the CD21 receptor revealed that increasing the number of repeats of A in the spacer from one to three resulted in continuous improvements in the biorecognition by the CD21 receptor; the increase from three to four repeats showed no significant effect. This work showed the potential of the OBOC combinatorial approach to select peptide ligands as targeting moieties for CD21 specific polymeric drug carriers.
Assuntos
Acrilamidas/química , Peptídeos/química , Receptores de Complemento 3d/metabolismo , Ensaio de Imunoadsorção Enzimática , Fluorescência , Corantes Fluorescentes/química , Peptídeos/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Mycotic aortic aneurysms are rare complications of systemic tuberculosis that affect very few patients. We report a case of a false aneurysm of the visceral segment of the aorta that was associated with tuberculous vertebral osteomyelitis. Both conditions were successfully treated with antituberculous chemotherapy and a combined surgical procedure, ie, aneurysm resection and homograft implantation, followed by orthopedic stabilization of the spine.
Assuntos
Falso Aneurisma/etiologia , Aneurisma Infectado/etiologia , Aneurisma da Aorta Abdominal/etiologia , Vértebras Lombares , Osteomielite/terapia , Vértebras Torácicas , Tuberculose da Coluna Vertebral/terapia , Falso Aneurisma/diagnóstico por imagem , Falso Aneurisma/cirurgia , Aneurisma Infectado/diagnóstico por imagem , Aneurisma Infectado/cirurgia , Antituberculosos/uso terapêutico , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/cirurgia , Implante de Prótese Vascular , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Osteomielite/complicações , Osteomielite/diagnóstico por imagem , Fusão Vertebral , Tomografia Computadorizada por Raios X , Tuberculose da Coluna Vertebral/complicações , Tuberculose da Coluna Vertebral/diagnóstico por imagemRESUMO
Mycobacterium caprae, a recently defined member of the Mycobacterium tuberculosis complex, causes tuberculosis among animals and, to a limited extent, in humans in several European countries. To characterize M. caprae in comparison with other Mycobacterium tuberculosis complex members and to evaluate genotyping methods for this species, we analyzed 232 M. caprae isolates by mycobacterial interspersed repetitive unit (MIRU) genotyping and by spoligotyping. The isolates originated from 128 distinct epidemiological settings in 10 countries, spanning a period of 25 years. We found 78 different MIRU patterns (53 unique types and 25 clusters with group sizes from 2 to 9) but only 17 spoligotypes, giving Hunter-Gaston discriminatory indices of 0.941 (MIRU typing) and 0.665 (spoligotyping). For a subset of 103 M. caprae isolates derived from outbreaks or endemic foci, MIRU genotyping and IS 6110 restriction fragment length polymorphism were compared and shown to provide similar results. MIRU loci 4, 26, and 31 were most discriminant in M. caprae, followed by loci 10 and 16, a combination which is different than those reported to discriminate M. bovis best. M. caprae MIRU patterns together with published data were used for phylogenetic inference analysis employing the neighbor-joining method. M. caprae isolates were grouped together, closely related to the branches of classical M. bovis, M. pinnipedii, M. microti, and ancestral M. tuberculosis, but apart from modern M. tuberculosis. The analysis did not reflect geographic patterns indicative of origin or spread of M. caprae. Altogether, our data confirm M. caprae as a distinct phylogenetic lineage within the Mycobacterium tuberculosis complex.
Assuntos
Técnicas de Tipagem Bacteriana , Sequências Repetitivas Dispersas/genética , Mycobacterium/classificação , Tuberculose/epidemiologia , Animais , Animais Selvagens/microbiologia , Bovinos , Doenças dos Bovinos/microbiologia , Elementos de DNA Transponíveis/genética , Europa (Continente)/epidemiologia , Genótipo , Doenças das Cabras/microbiologia , Cabras/microbiologia , História do Século XX , Humanos , Repetições Minissatélites/genética , Mycobacterium/genética , Mycobacterium/isolamento & purificação , Oligonucleotídeos/análise , Polimorfismo de Fragmento de Restrição , Tuberculose/microbiologia , Tuberculose/veterináriaRESUMO
Twelve cases of Mycobacterium bovis subsp. caprae infection have occurred in four humans, three cattle, and five red deer in western Austria since 1994. DNA-fingerprinting of the isolates suggested transmission in and between these species over several years. Contact with cattle, but not with goats, was found to be associated with three of four human cases.
Assuntos
Doenças dos Bovinos/microbiologia , Cervos/microbiologia , Surtos de Doenças , Infecções por Mycobacterium/epidemiologia , Infecções por Mycobacterium/microbiologia , Mycobacterium bovis/classificação , Adulto , Animais , Áustria/epidemiologia , Bovinos , Impressões Digitais de DNA/métodos , Elementos de DNA Transponíveis , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Mycobacterium/transmissão , Mycobacterium bovis/genética , Polimorfismo de Fragmento de RestriçãoRESUMO
Resting CD4(+) T cells in the lymphoid tissue (LT) are essential producers of virions at the beginning of HIV infection in vivo. We previously developed a model that allowed in vitro infection of non-prestimulated T lymphocytes in the presence of autologous B lymphocytes and complement. In this study, we try to clarify the mechanism(s) responsible for virus transmission in unstimulated autologous B cell/T cell co-cultures. Ex vivo analyses of patient plasma samples revealed that HIV was opsonized. Flow cytometry showed that opsonized virus preferentially bound to complement receptor (CR)-2 on B lymphocytes in primary B cell/T cell co-cultures. As indicated by cytokine measurements and transwell experiments, soluble factors seemed to play a minor role in enabling infection. Rather, direct interaction between B and T lymphocytes and direct binding of opsonized virus to CR2 on B cells turned out to be essential for productive infection. Antibodies blocking cell-cell adhesion inhibited p24 antigen production. An anti-CR2 antibody blocking C3d-CR2 binding also significantly reduced viral replication. Since the infection of unstimulated T cells by opsonized primary HIV isolates in the presence of B cells was highly efficient independent of the tropism of the virus, this mechanism may be critical in the pathogenesis of HIV.