143 research outputs found
Could halophilic archaea improve the traditional salted anchovies (Engraulis encrasicholus L) safety and quality?
Aims: The positive influence of two selected extremely halophilic archaea
strains in the production of salted anchovies (Engraulis encrasicolus, L., 1758)
was highlighted.
Methods and Results: Anchovies produced with salt artificially contaminated
with halophiles exhibited lower loads of staphylococci, Enterobacteriaceae and
lactic acid bacteria, and a reduced content of histamine as well as an improved
organoleptic acceptance.
Conclusions: The findings of this survey are expected to enhance the safety of
salted anchovies, with regard to the histamine formation during ripening, and
to improve the sensory attributes of this product.
Significance and Impact of the Study: This study represents the first report on
the positive influence of halophilic archaea in traditional salted anchovies production,
thus suggesting new perspectives about a conscious employment of
properly selected haloarchaea strains in this traditional manufactur
Production of probiotic bovine salami using Lactobacillus plantarum 299v as adjunct
BACKGROUND:
Five probiotic lactobacilli were tested, alone or in combination with two commercial starters, to select the most suitable strain for a probiotic bovine salami production. Lactobacillus plantarum 299v was used with both starters, to make salami according to a traditional recipe. Salami obtained by using just the starters and by spontaneous fermentation, served as control. Microbial dynamics, as well as the main physico-chemical parameters, were monitored throughout ripening. The survival of probiotic 299v was confirmed by strains' tracking by means of RAPD-PCR coupled to a culture-independent approach PCR-DGGE-based.
RESULTS:
The results showed a remarkable viability of the probiotic strain even after 60 days of storage. Experimental salami exhibited the same level of sensory acceptance of control salami, were hygienically safe, and characterised by pH, weight loss and microbiological loads within the ranges conventionally advocated for optimal fermented sausages.
CONCLUSION:
Outcomes indicate the workable possibility of using second-quality beef cuts for probiotic salami production. © 2017 Society of Chemical Industry
The Staphylococcus aureus Peptidoglycan Protects Mice against the Pathogen and Eradicates Experimentally Induced Infection
Staphylococcus aureus, in spite of antibiotics, is still a major human pathogen causing a wide range of infections. The present study describes the new vaccine A170PG, a peptidoglycan-based vaccine. In a mouse model of infection, A170PG protects mice against a lethal dose of S. aureus. Protection lasts at least 40 weeks and correlates with increased survival and reduced colonization. Protection extends into drug-resistant (MRSA or VISA) and genetically diverse clinical strains. The vaccine is effective when administered - in a single dose and without adjuvant - by the intramuscular, intravenous or the aerosol routes and induces active as well as passive immunization. Of note, A170PG also displays therapeutic activity, eradicating staphylococci, even when infection is systemic. Sustained antibacterial activity and induction of a strong and rapid anti-inflammatory response are the mechanisms conferring therapeutic efficacy to A170PG
Characterization in the archaeological excavation site of heterotrophic bacteria and fungi of deteriorated wall painting of Herculaneum in Italy.
Microbiological characterization of frescos in four different famous locations of excavation sites of Herculaneum (the Collegio degli Augustali, Casa del Colonnato Tuscanico, Casa dello Scheletro and Casa del Gran Portale), were carried out. The use of infrared thermography allowed us to detect sample points on frescos with greatest moisture not visible to the naked eye, resulting in structural damage. The microclimatic conditions provided perfect habitat for bacteria, especially of spore forming and mould. In fact, heterotrophic bacteria were prevalent in all wall paintings monitored, whereas fungi were also detected but at lower levels. Cultural–based methods allowed to obtain a total of 48 bacteria and 23 mould isolates molecularly identified by 16S and 26S rRNA partial sequence analysis. With this approach, Bacillus-related species (B. cereus/B. thuringiensis group, B. simplex/B.muralis group, B. megaterium and B. subtilis) were isolated in all sample points analysed with the exception of the Casa dello Scheletro in which Micrococcus luteus/Arthrobacter sp./Variovorax sp. group and Streptomyces fragilis were found. Mould isolates were closest related to different genera in which predominated Aspergillus, Penicillium and Fusarium together with the unusual genera as Microascus and Coprinus. Sequencing of the 16S ribosomal DNAs, selected on the basis of DGGE profiling, enabled detection of bacterial species closest related to Microbacterium groups in all sample points analysed, also associated with Brevibacterium, Streptomyces and Stenotrophomonas
A cross-center smoothness prior for variational Bayesian brain tissue segmentation
Suppose one is faced with the challenge of tissue segmentation in MR images,
without annotators at their center to provide labeled training data. One option
is to go to another medical center for a trained classifier. Sadly, tissue
classifiers do not generalize well across centers due to voxel intensity shifts
caused by center-specific acquisition protocols. However, certain aspects of
segmentations, such as spatial smoothness, remain relatively consistent and can
be learned separately. Here we present a smoothness prior that is fit to
segmentations produced at another medical center. This informative prior is
presented to an unsupervised Bayesian model. The model clusters the voxel
intensities, such that it produces segmentations that are similarly smooth to
those of the other medical center. In addition, the unsupervised Bayesian model
is extended to a semi-supervised variant, which needs no visual interpretation
of clusters into tissues.Comment: 12 pages, 2 figures, 1 table. Accepted to the International
Conference on Information Processing in Medical Imaging (2019
ABCD Neurocognitive Prediction Challenge 2019: Predicting individual fluid intelligence scores from structural MRI using probabilistic segmentation and kernel ridge regression
We applied several regression and deep learning methods to predict fluid
intelligence scores from T1-weighted MRI scans as part of the ABCD
Neurocognitive Prediction Challenge (ABCD-NP-Challenge) 2019. We used voxel
intensities and probabilistic tissue-type labels derived from these as features
to train the models. The best predictive performance (lowest mean-squared
error) came from Kernel Ridge Regression (KRR; ), which produced a
mean-squared error of 69.7204 on the validation set and 92.1298 on the test
set. This placed our group in the fifth position on the validation leader board
and first place on the final (test) leader board.Comment: Winning entry in the ABCD Neurocognitive Prediction Challenge at
MICCAI 2019. 7 pages plus references, 3 figures, 1 tabl
Flexible Bayesian Modelling for Nonlinear Image Registration
We describe a diffeomorphic registration algorithm that allows groups of
images to be accurately aligned to a common space, which we intend to
incorporate into the SPM software. The idea is to perform inference in a
probabilistic graphical model that accounts for variability in both shape and
appearance. The resulting framework is general and entirely unsupervised. The
model is evaluated at inter-subject registration of 3D human brain scans. Here,
the main modeling assumption is that individual anatomies can be generated by
deforming a latent 'average' brain. The method is agnostic to imaging modality
and can be applied with no prior processing. We evaluate the algorithm using
freely available, manually labelled datasets. In this validation we achieve
state-of-the-art results, within reasonable runtimes, against previous
state-of-the-art widely used, inter-subject registration algorithms. On the
unprocessed dataset, the increase in overlap score is over 17%. These results
demonstrate the benefits of using informative computational anatomy frameworks
for nonlinear registration.Comment: Accepted for MICCAI 202
Spinal cord grey matter segmentation challenge
An important image processing step in spinal cord magnetic resonance imaging is the ability to reliably and accurately segment grey and white matter for tissue specific analysis. There are several semi- or fully-automated segmentation methods for cervical cord cross-sectional area measurement with an excellent performance close or equal to the manual segmentation. However, grey matter segmentation is still challenging due to small cross-sectional size and shape, and active research is being conducted by several groups around the world in this field. Therefore a grey matter spinal cord segmentation challenge was organised to test different capabilities of various methods using the same multi-centre and multi-vendor dataset acquired with distinct 3D gradient-echo sequences. This challenge aimed to characterize the state-of-the-art in the field as well as identifying new opportunities for future improvements. Six different spinal cord grey matter segmentation methods developed independently by various research groups across the world and their performance were compared to manual segmentation outcomes, the present gold-standard. All algorithms provided good overall results for detecting the grey matter butterfly, albeit with variable performance in certain quality-of-segmentation metrics. The data have been made publicly available and the challenge web site remains open to new submissions. No modifications were introduced to any of the presented methods as a result of this challenge for the purposes of this publication
Conjugative Botulinum Neurotoxin-Encoding Plasmids in Clostridium botulinum
Clostridium botulinum produces seven distinct serotypes of botulinum neurotoxins (BoNTs). The genes encoding different subtype neurotoxins of serotypes A, B, F and several dual neurotoxin-producing strains have been shown to reside on plasmids, suggesting that intra- and interspecies transfer of BoNT-encoding plasmids may occur. The objective of the present study was to determine whether these C. botulinum BoNT-encoding plasmids are conjugative.C. botulinum BoNT-encoding plasmids pBotCDC-A3 (strain CDC-A3), pCLJ (strain 657Ba) and pCLL (strain Eklund 17B) were tagged with the erythromycin resistance marker (Erm) using the ClosTron mutagenesis system by inserting a group II intron into the neurotoxin genes carried on these plasmids. Transfer of the tagged plasmids from the donor strains CDC-A3, 657Ba and Eklund 17B to tetracycline-resistant recipient C. botulinum strains was evaluated in mating experiments. Erythromycin and tetracycline resistant transconjugants were isolated from donor:recipient mating pairs tested. Transfer of the plasmids to the transconjugants was confirmed by pulsed-field gel electrophoresis (PFGE) and Southern hybridizations. Transfer required cell-to-cell contact and was DNase resistant. This indicates that transfer of these plasmids occurs via a conjugation mechanism.This is the first evidence supporting conjugal transfer of native botulinum neurotoxin-encoding plasmids in C. botulinum, and provides a probable mechanism for the lateral distribution of BoNT-encoding plasmids to other C. botulinum strains. The potential transfer of C. botulinum BoNT-encoding plasmids to other bacterial hosts in the environment or within the human intestine is of great concern for human pathogenicity and necessitates further characterization of these plasmids
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