Unprecedented Melioidosis Cases in Northern Australia Caused by an Asian Burkholderia pseudomallei Strain Identified by Using Large-Scale Comparative Genomics.

Melioidosis is a disease of humans and animals that is caused by the saprophytic bacterium Burkholderia pseudomallei. Once thought to be confined to certain locations, the known presence of B. pseudomallei is expanding as more regions of endemicity are uncovered. There is no vaccine for melioidosis, and even with antibiotic administration, the mortality rate is as high as 40% in some regions that are endemic for the infection. Despite high levels of recombination, phylogenetic reconstruction of B. pseudomallei populations using whole-genome sequencing (WGS) has revealed surprisingly robust biogeographic separation between isolates from Australia and Asia. To date, there have been no confirmed autochthonous melioidosis cases in Australia caused by an Asian isolate; likewise, no autochthonous cases in Asia have been identified as Australian in origin. Here, we used comparative genomic analysis of 455 B. pseudomallei genomes to confirm the unprecedented presence of an Asian clone, sequence type 562 (ST-562), in Darwin, northern Australia. First observed in Darwin in 2005, the incidence of melioidosis cases attributable to ST-562 infection has steadily risen, and it is now a common strain in Darwin. Intriguingly, the Australian ST-562 appears to be geographically restricted to a single locale and is genetically less diverse than other common STs from this region, indicating a recent introduction of this clone into northern Australia. Detailed genomic and epidemiological investigations of new clinical and environmental B. pseudomallei isolates in the Darwin region and ST-562 isolates from Asia will be critical for understanding the origin, distribution, and dissemination of this emerging clone in northern Australia.

Use of Whole-Genome Sequencing to Link Burkholderia pseudomallei from Air Sampling to Mediastinal Melioidosis, Australia.

The frequency with which melioidosis results from inhalation rather than percutaneous inoculation or ingestion is unknown. We recovered Burkholderia pseudomallei from air samples at the residence of a patient with presumptive inhalational melioidosis and used whole-genome sequencing to link the environmental bacteria to B. pseudomallei recovered from the patient.

Whole-genome sequencing confirms that Burkholderia pseudomallei multilocus sequence types common to both Cambodia and Australia are due to homoplasy.

Burkholderia pseudomallei isolates with shared multilocus sequence types (STs) have not been isolated from different continents. We identified two STs shared between Australia and Cambodia. Whole-genome analysis revealed substantial diversity within STs, correctly identified the Asian or Australian origin, and confirmed that these shared STs were due to homoplasy.

Development and evaluation of a multiplex serodiagnostic bead assay (BurkPx) for accurate melioidosis diagnosis.

Burkholderia pseudomallei, the causative agent of melioidosis, is a gram-negative soil bacterium well recognized in Southeast Asia and northern Australia. However, wider and expanding global distribution of B. pseudomallei has been elucidated. Early diagnosis is critical for commencing the specific therapy required to optimize outcome. Serological testing using the indirect hemagglutination (IHA) antibody assay has long been used to augment diagnosis of melioidosis and to monitor progress. However, cross reactivity and prior exposure may complicate the diagnosis of current clinical disease (melioidosis). The goal of our study was to develop and initially evaluate a serology assay (BurkPx) that capitalized upon host response to multiple antigens. Antigens were selected from previous studies for expression/purification and conjugation to microspheres for multiantigen analysis. Selected serum samples from non-melioidosis controls and serial samples from culture-confirmed melioidosis patients were used to characterize the diagnostic power of individual and combined antigens at two times post admission. Multiple variable models were developed to evaluate multivariate antigen reactivity, identify important antigens, and determine sensitivity and specificity for the diagnosis of melioidosis. The final multiplex assay had a diagnostic sensitivity of 90% and specificity of 93%, which was superior to any single antigen in side-by-side comparisons. The sensitivity of the assay started at >85% for the initial serum sample after admission and increased to 94% 21 days later. Weighting antigen contribution to each model indicated that certain antigen contributed to diagnosis more than others, which suggests that the number of antigens in the assay can be decreased. In summation, the BurkPx assay can facilitate the diagnosis of melioidosis and potentially improve on currently available serology assays. Further evaluation is now required in both melioidosis-endemic and non-endemic settings.

The Effects of Signal Erosion and Core Genome Reduction on the Identification of Diagnostic Markers.

UNLABELLED: Whole-genome sequence (WGS) data are commonly used to design diagnostic targets for the identification of bacterial pathogens. To do this effectively, genomics databases must be comprehensive to identify the strict core genome that is specific to the target pathogen. As additional genomes are analyzed, the core genome size is reduced and there is erosion of the target-specific regions due to commonality with related species, potentially resulting in the identification of false positives and/or false negatives. IMPORTANCE: A comparative analysis of 1,130 Burkholderia genomes identified unique markers for many named species, including the human pathogens B. pseudomallei and B. mallei Due to core genome reduction and signature erosion, only 38 targets specific to B. pseudomallei/mallei were identified. By using only public genomes, a larger number of markers were identified, due to undersampling, and this larger number represents the potential for false positives. This analysis has implications for the design of diagnostics for other species where the genomic space of the target and/or closely related species is not well defined.

A prospective study of melioidosis after environmental exposure of healthy participants to Burkholderia pseudomallei during a muddy endurance challenge.

In a prospective study of 123 healthy adults competing in a mud-exposing endurance challenge in the melioidosis-endemic tropical north of the Northern Territory of Australia, there were no asymptomatic seroconversions to Burkholderia pseudomallei using indirect hemagglutination assay. However, one competitor developed melioidosis attributable to infection acquired during the event.

Development of a prototype lateral flow immunoassay (LFI) for the rapid diagnosis of melioidosis.

Burkholderia pseudomallei is a soil-dwelling bacterium and the causative agent of melioidosis. Isolation of B. pseudomallei from clinical samples is the "gold standard" for the diagnosis of melioidosis; results can take 3-7 days to produce. Alternatively, antibody-based tests have low specificity due to a high percentage of seropositive individuals in endemic areas. There is a clear need to develop a rapid point-of-care antigen detection assay for the diagnosis of melioidosis. Previously, we employed In vivo Microbial Antigen Discovery (InMAD) to identify potential B. pseudomallei diagnostic biomarkers. The B. pseudomallei capsular polysaccharide (CPS) and numerous protein antigens were identified as potential candidates. Here, we describe the development of a diagnostic immunoassay based on the detection of CPS. Following production of a CPS-specific monoclonal antibody (mAb), an antigen-capture immunoassay was developed to determine the concentration of CPS within a panel of melioidosis patient serum and urine samples. The same mAb was used to produce a prototype Active Melioidosis Detect Lateral Flow Immunoassay (AMD LFI); the limit of detection of the LFI for CPS is comparable to the antigen-capture immunoassay (∼0.2 ng/ml). The analytical reactivity (inclusivity) of the AMD LFI was 98.7% (76/77) when tested against a large panel of B. pseudomallei isolates. Analytical specificity (cross-reactivity) testing determined that 97.2% of B. pseudomallei near neighbor species (35/36) were not reactive. The non-reactive B. pseudomallei strain and the reactive near neighbor strain can be explained through genetic sequence analysis. Importantly, we show the AMD LFI is capable of detecting CPS in a variety of patient samples. The LFI is currently being evaluated in Thailand and Australia; the focus is to optimize and validate testing procedures on melioidosis patient samples prior to initiation of a large, multisite pre-clinical evaluation.

Accurate and rapid identification of the Burkholderia pseudomallei near-neighbour, Burkholderia ubonensis, using real-time PCR.

Burkholderia ubonensis is an environmental bacterium belonging to the Burkholderia cepacia complex (Bcc), a group of genetically related organisms that are associated with opportunistic but generally nonfatal infections in healthy individuals. In contrast, the near-neighbour species Burkholderia pseudomallei causes melioidosis, a disease that can be fatal in up to 95% of cases if left untreated. B. ubonensis is frequently misidentified as B. pseudomallei from soil samples using selective culturing on Ashdown's medium, reflecting both the shared environmental niche and morphological similarities of these species. Additionally, B. ubonensis shows potential as an important biocontrol agent in B. pseudomallei-endemic regions as certain strains possess antagonistic properties towards B. pseudomallei. Current methods for characterising B. ubonensis are laborious, time-consuming and costly, and as such this bacterium remains poorly studied. The aim of our study was to develop a rapid and inexpensive real-time PCR-based assay specific for B. ubonensis. We demonstrate that a novel B. ubonensis-specific assay, Bu550, accurately differentiates B. ubonensis from B. pseudomallei and other species that grow on selective Ashdown's agar. We anticipate that Bu550 will catalyse research on B. ubonensis by enabling rapid identification of this organism from Ashdown's-positive colonies that are not B. pseudomallei.

Abaulamento em região inguinal / Swelling of inguinal region

Queixa de abaulamento em região inguinal é muito frequente na prática médica. Neste trabalho, os autores realizaram revisão bibliográfica sobre o tópico hérnia inguinal, abordando seu quadro clínico, subtipos, diagnóstico diferencial e tratamento.

Nevralgia do trigêmeo associada à hanseníase / Hanseniase associated Trigeminal Nevralgia

A hanseníase é uma doença infecto-contagiosa, que além de alterações dermatológicas, possui manifestações neurológicas. Relatamos o caso de um homem de 66 anos, que apresentou nevralgia do trigêmeo após ter apresentado quadro de hanseníase.

Hansen's disease is an infectious disease that presents with skin changes, as well as neurological features. We report a case of a 66 years man, who presented with trigeminal neuralgia after developing Hansen's disease.

A universidade inserida na comunidade: conhecimentos, atitudes e comportamentos de adolescentes de uma escola pública frente a doenças sexualmente transmissíveis / The university in the community: knowledge, attitudes and behavior of adolescents from a public school regarding sexually transmitted diseases

Introdução: As doenças sexualmente transmissíveis (DSTs) são infecções disseminadas principalmente através do contato sexual. A maioria dos casos ocorre em adolescentes e adultos jovens. O presente estudo visa avaliar conhecimento, atitudes, comportamento e transmissão das DSTs em adolescentes de uma escola pública, após a inserção da Universidade na comunidade através de trabalhos desenvolvidos pelos alunos de Medicina da ULBRA. Métodos: Estudo descritivo, tipo inquérito epidemiológico, de caráter quantitativo, com alunos de 7ª e 8 ª séries de uma escola municipal de Canoas, RS. Resultados: Participaram do estudo 185 alunos com média de idade de 15,3 anos. Quando questionados se conheciam DSTs, 91,4% responderam positivamente, sendo a síndrome da imunodeficiência adquirida a doença mais citada. A maioria recebe informações acerca desse assunto na escola. A média de idade de início das atividades sexuais foi de 13,9 anos. Quanto às relações sexuais, 44,9% já a iniciaram e 92,8% destes fazem uso do preservativo, sendo a prevenção da gravidez o motivo mais apontado. Apenas dois alunos referiram ocorrência de infecção no passado. Conclusão: A idade de início das relações sexuais é precoce. Um número considerável de jovens mostra-se consciente e faz uso de preservativo, embora não seja com o intuito de prevenir doenças, mas de evitar gestações indesejadas. A maioria dos jovens apresenta bom nível de conhecimento sobre o assunto. Sendo assim, é de grande valia a intervenção da Universidade nas escolas, uma vez que esses são os locais onde os adolescentes afirmam receber a maioria das informações acerca das DSTs.

Introduction: Sexually transmitted diseases (STDs) are infections spread mainly through sexual contact. Most cases occur in adolescents and young adults. The present study aims to assess the knowledge, attitudes, behavior and transmission of STDs in adolescents from a public school after University intervention in the community through educational work done by medical students of ULBRA. Methods: A descriptive, epidemiological investigation with a quantitative approach, with 7th and 8th graders of a municipal school of Canoas, RS. Results: The study included 185 students with a mean age of 15.3 years. When asked if they knew STDs, 91.4% answered “yes”, with acquired immunodeficiency syndrome being the most cited disease. Most students receive information about this subject at school. The mean age of sexual initiation was 13.9 years. Regarding sex intercourse, 44.9% had already started it and 92.8% of these reported using condoms, pregnancy prevention being the most frequently reason for doing so. Only two students reported occurrence of infection in the past. Conclusion: The age of onset of sexual activity is early. A considerable number of young people is aware and uses condoms, although not with the intention of preventing diseases, but to avoid unwanted pregnancies. Most young people are fairly knowledgeable about the subject. Therefore, the University’s intervention in schools is highly valuable, since these are the places where teens claim to receive most information about STDs.