Detection, Identification, and Inactivation of Histamine-forming Bacteria in Seafood: A Mini-review.

Seafood is one of the essential sources of nutrients for the human diet. However, they can be subject to contamination and can cause foodborne illnesses, including scombroid fish poisoning caused by histamine. Many microorganisms can produce enzymes that eventually decompose endogenous histidine to histamine in postmortem fish muscles and tissues. One of these is histamine-forming bacteria (HFB), primarily found in the gills, gut, and skin of fishes. Previous studies linked a plethora of Gram-negative HFB including Morganella spp. and Photobacterium spp. to scombroid fish poisoning from many types of seafood, especially the Scombridae family. These bacteria possess the hdc gene to produce histidine decarboxylase enzyme. It was reported that Gram-negative HFB produced 6345 ppm in tuna and 1223 ppm in Spanish mackerel. Interestingly, Gram-positive HFB have been isolated in the seafood samples with lower histamine levels. It suggests that Gram-negative HFB are the major contributor to the accumulation of histamine in seafood. Several analytical methods are available to detect and identify HFB and their histamine metabolites from seafood substrates. Rapid test kits can be used in food production settings for early detection of histamine to avoid food intoxication. Furthermore, high hydrostatic pressure and irradiation treatment could prevent the proliferation of HFB and inactivate the existing histidine decarboxylase (HDC) activity. As demonstrated in different seafood model systems, the HDC activity was deactivated at a maximum high hydrostatic pressure level of 400 MPa. The complete inactivation of HFB was achieved by gamma irradiation at a dose of 4.0 kGy. Other postharvest treatments, like enzymatic degradation and electrolyzed oxidizing water, were studied as sustainable methods for bacterial growth prevention and enzyme inactivation. However, other HFB react differently to these treatment conditions, and further studies are recommended.

Challenges and Opportunities in Clinical Diagnostic Routine of Envenomation Using Blood Plasma Proteomics.

Specific and sensitive tools for the diagnosis and monitoring of accidents by venomous animals are urgently needed. Several diagnostic and monitoring assays have been developed; however, they have not yet reached the clinic. This has resulted in late diagnoses, which represents one of the main causes of progression from mild to severe disease. Human blood is a protein-rich biological fluid that is routinely collected in hospital settings for diagnostic purposes, which can translate research progress from the laboratory to the clinic. Although it is a limited view, blood plasma proteins provide information about the clinical picture of envenomation. Proteome disturbances in response to envenomation by venomous animals have been identified, allowing mass spectrometry (MS)-based plasma proteomics to emerge as a tool in a range of clinical diagnostics and disease management that can be applied to cases of venomous animal envenomation. Here, we provide a review of the state of the art on routine laboratory diagnoses of envenomation by snakes, scorpions, bees, and spiders, as well as a review of the diagnostic methods and the challenges encountered. We present the state of the art on clinical proteomics as the standardization of procedures to be performed within and between research laboratories, favoring a more excellent peptide coverage of candidate proteins for biomarkers. Therefore, the selection of a sample type and method of preparation should be very specific and based on the discovery of biomarkers in specific approaches. However, the sample collection protocol (e.g., collection tube type) and the processing procedure of the sample (e.g., clotting temperature, time allowed for clotting, and anticoagulant used) are equally important to eliminate any bias.

Ecological modelling approaches for predicting emergent properties in microbial communities.

Recent studies have brought forward the critical role of emergent properties in shaping microbial communities and the ecosystems of which they are a part. Emergent properties-patterns or functions that cannot be deduced linearly from the properties of the constituent parts-underlie important ecological characteristics such as resilience, niche expansion and spatial self-organization. While it is clear that emergent properties are a consequence of interactions within the community, their non-linear nature makes mathematical modelling imperative for establishing the quantitative link between community structure and function. As the need for conservation and rational modulation of microbial ecosystems is increasingly apparent, so is the consideration of the benefits and limitations of the approaches to model emergent properties. Here we review ecosystem modelling approaches from the viewpoint of emergent properties. We consider the scope, advantages and limitations of Lotka-Volterra, consumer-resource, trait-based, individual-based and genome-scale metabolic models. Future efforts in this research area would benefit from capitalizing on the complementarity between these approaches towards enabling rational modulation of complex microbial ecosystems.

Odontologia para Pacientes com Necessidades Especiais: uma análise das estruturas curriculares dos cursos de Odontologia da região Nordeste / Dentistry for Patients with Special Needs: an analysis of the curricular structures of Dentistry courses in the Northeast region

O estudo objetivou analisar as estruturas curriculares dos cursos de Odontologia da região Nordeste e investigar a presença do componente curricular Odontologia para Pacientes com Necessidades Especiais(OPNE). Trata-se de um estudo seccional, descritivo e quantitativo. Os dados foram coletados entre junho e dezembro de 2020 no sítio eletrônico do Ministério da Educação (e-MEC) e nos portaisdas instituições de ensino identificadas,comanálise das estruturas curriculares dos cursos. Havia138 cursos de Odontologia autorizados e cadastrados na plataformaedestes, seteforam excluídos por ausência de portal atualizado ou por ainda não ter formado pelo menos umaturma. Dos 131 cursos de graduação em Odontologia analisados, verificou-se que 62 IES (47,30%) ofertavam o componente OPNE, dentre as quais53 (40,50%) o ofertavam como componente obrigatório.O estado da Paraíba apresentou a maior frequência (n=13, 86,7%) de cursos que ofertam o componente curricular, enquanto o estado de Sergipe obteve a menor frequência (n=1, 16,7%).Conclui-se que o componente curricular OPNE é pouco ofertado nos cursos de graduação em Odontologia na região Nordeste,o que pode impactardiretamente na capacitação dos profissionais para prestar um melhor cuidado de saúde bucal para essa população (AU).

The study aimed to analyze the curricular structures of the Dentistry courses in the Northeast region and investigate the curricular component named DPSN (Dentistry for Patients with Special Needs). This is a sectional, descriptive and quantitative study. The data were collected between June and November 2020 on the Ministry of Education's (e-MEC) website and the educational institutions' portals identified by analyzing the curricular structures of the courses. There were 138 authorized Dentistry courses registered on the platform; and, of these, seven were excluded for lack of an updated portal or for not having at least one formed class. Of the 131 analyzed undergraduate courses in Dentistry, it was found that 62 HEI (47.30%) offered the DPSN component, among which 53 (40.50%) offered it as a compulsory component. The state of Paraíba showed the highest frequency (n=13, 86.7%) of the courses offering the curricular component, while the state of Sergipe obtained the lowest frequency (n=1, 16.7%). It is concluded that the DPSN curricular component islittle offered in the undergraduate courses in Dentistry in the Northeast region and directly impacts professionals' training to provide better oral health care for this population (AU).

Dongsha Atoll is an important stepping-stone that promotes regional genetic connectivity in the South China Sea.

BACKGROUND: Understanding region-wide patterns of larval connectivity and gene flow is crucial for managing and conserving marine biodiversity. Dongsha Atoll National Park (DANP), located in the northern South China Sea (SCS), was established in 2007 to study and conserve this diverse and remote coral atoll. However, the role of Dongsha Atoll in connectivity throughout the SCS is seldom studied. In this study, we aim to evaluate the role of DANP in conserving regional marine biodiversity. METHODS: In total, 206 samples across nine marine species were collected and sequenced from Dongsha Atoll, and these data were combined with available sequence data from each of these nine species archived in the Genomic Observatories Metadatabase (GEOME). Together, these data provide the most extensive population genetic analysis of a single marine protected area. We evaluate metapopulation structure for each species by using a coalescent sampler, selecting among panmixia, stepping-stone, and island models of connectivity in a likelihood-based framework. We then completed a heuristic graph theoretical analysis based on maximum dispersal distance to get a sense of Dongsha's centrality within the SCS. RESULTS: Our dataset yielded 111 unique haplotypes across all taxa at DANP, 58% of which were not sampled elsewhere. Analysis of metapopulation structure showed that five out of nine species have strong regional connectivity across the SCS such that their gene pools are effectively panmictic (mean pelagic larval duration (PLD) = 78 days, sd = 60 days); while four species have stepping-stone metapopulation structure, indicating that larvae are exchanged primarily between nearby populations (mean PLD = 37 days, sd = 15 days). For all but one species, Dongsha was ranked within the top 15 out of 115 large reefs in the South China Sea for betweenness centrality. Thus, for most species, Dongsha Atoll provides an essential link for maintaining stepping-stone gene flow across the SCS. CONCLUSIONS: This multispecies study provides the most comprehensive examination of the role of Dongsha Atoll in marine connectivity in the South China Sea to date. Combining new and existing population genetic data for nine coral reef species in the region with a graph theoretical analysis, this study provides evidence that Dongsha Atoll is an important hub for sustaining connectivity for the majority of coral-reef species in the region.

Mapping Salmonella typhimurium pathways using 13C metabolic flux analysis.

In the last years, Salmonella has been extensively studied not only due to its importance as a pathogen, but also as a host to produce pharmaceutical compounds. However, the full exploitation of Salmonella as a platform for bioproduct delivery has been hampered by the lack of information about its metabolism. Genome-scale metabolic models can be valuable tools to delineate metabolic engineering strategies as long as they closely represent the actual metabolism of the target organism. In the present study, a 13C-MFA approach was applied to map the fluxes at the central carbon pathways of S. typhimurium LT2 growing at glucose-limited chemostat cultures. The experiments were carried out in a 2L bioreactor, using defined medium enriched with 20% 13C-labeled glucose. Metabolic flux distributions in central carbon pathways of S. typhimurium LT2 were estimated using OpenFLUX2 based on the labeling pattern of biomass protein hydrolysates together with biomass composition. The results suggested that pentose phosphate is used to catabolize glucose, with minor fluxes through glycolysis. In silico simulations, using Optflux and pFBA as simulation method, allowed to study the performance of the genome-scale metabolic model. In general, the accuracy of in silico simulations was improved by the superimposition of estimated intracellular fluxes to the existing genome-scale metabolic model, showing a better fitting to the experimental extracellular fluxes, whereas the intracellular fluxes of pentose phosphate and anaplerotic reactions were poorly described.

Estimation of biomass composition from genomic and transcriptomic information.

Given the great potential impact of the growing number of complete genome-scale metabolic network reconstructions of microorganisms, bioinformatics tools are needed to simplify and accelerate the course of knowledge in this field. One essential component of a genome-scale metabolic model is its biomass equation, whose maximization is one of the most common objective functions used in Flux Balance Analysis formulations. Some components of biomass, such as amino acids and nucleotides, can be estimated from genome information, providing reliable data without the need of performing lab experiments. In this work a java tool is proposed that estimates microbial biomass composition in amino acids and nucleotides, from genome and transcriptomic information, using as input files sequences in FASTA format and files with transcriptomic data in the csv format. This application allows to obtain the results rapidly and is also a user-friendly tool for users with any or little background in informatics (http://darwin.di.uminho.pt/biomass/). The results obtained using this tool are fairly close to experimental data, showing that the estimation of amino acid and nucleotide compositions from genome information and from transcriptomic data is a good alternative when no experimental data is available.

Características clínicas, epidemológicas e microscópicas do câncer bucal diagnosticado na Universidade Federal de Alfenas / Clinical, epidemiological and microscopic features of oral cancer as diagnosed at the University of Alfenas

O presente trabalho teve por objetivo caracterizar e comparar as características clínicas e demográficas dos pacientes portadores de câncer bucal e avaliar os aspectos microscópicos de cada neoplasia, baseando-se na graduação histopatológica de malignidade. Foi realizado um levantamento de todas as neoplasias malignas diagnosticadas e arquivadas no Laboratório de Anatomia Patológica da Universidade Federal de Alfenas desde janeiro de 1998 até dezembro de 2006 e constatou-se um número de 49 tumores. Os resultados demonstraram que, dessas 49 lesões,43 eram carcinomas espinocelulares, três eram neoplasias malignas de glândulas salivares e os demais eram carcinomas in situ, microinvasivos e verrucosos. Os tumores foram mais prevalentes em pacientes leucodermas, com idades entre 51 e 60 anos, e do gênero masculino. As lesões se localizavam com maior frequência em borda lateral de língua e se apresentavam na forma de úlceras infiltrativas. Constatou-se também que os tumores, em sua maioria,eram carcinomas espinocelulares bem diferenciados e apresentavam um índice de graduação histopatológica de malignidade entre 4 e 8. Concluiu-se que o câncer bucal ainda é uma lesão bastante prevalente e que tem uma predileção por pacientes leucodermas, acima de 50 anos de idade e do gênero masculino.