605 research outputs found
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COVID-19 and Gastrointestinal Symptoms-A Case Report.
COVID-19, a new illness secondary to a novel Coronavirus emerged in December 2019 in China. Our early understanding of the clinical features of COVID-19 has been based on case series emerging from the first outbreak in Wuhan. These features included fever, a dry cough, myalgia and dyspnea. Gastrointestinal symptoms were rarely reported as a key feature. We present a case report of a 74-year-old male who presented with symptoms of gastroenteritis and subsequently tested positive for COVID-19. This article aims to highlight an uncommon presentation of COVID-19 and that a high index of suspicion is required for COVID-19 in older people given their greater likelihood of presenting atypically
Development of an optimized technique for the recovery of H. pylori from water and drinking water biofilms
At present, the route of transmission is perhaps one of the most controversialareas of
Helicobacter pylori research. Drinking water and associated biofilms have been
suggested as possible environmental reservoirs for the bacterium, however, successful and consistent detection of the bacterium in real systems has not yet been accomplished. A new protocol that offers improved recovery ratings of H. pylori from water and associated-biofilms has been developed and evaluated. This protocol includes optimized incubation atmospheres and a new recovery culture medium, as well as an assessmentof existing techniques for the detachment of H. pylori from surfaces. Even though obvious advantages in terms of cell counts are obtained using this method,
certain problems, such as contamination by faster-growing species of the culture medium
in heavily contaminated waters may still hinder a successful recovery of the pathogen.Future research will involve further improvement of the protocol and monitoring
of real drinking water distribution systems.Unit of Helicobacter/Campylobacter of the Center of Bacteriology of INSA para a Ciência e a Tecnologia (FCT) ; European Commission Research Project SAFER
Tracking persistence of Helicobacter pylori in potable water biofilms using novel 16S rRNA peptide nucleic acid probes
A two stage chemostat system was used to study the pathogenic
bacteria H. pylori association to drinking water biofilms. After
allowing one week old biofilms to be grown on stainless steel
coupons the system was inoculated with the pathogen that was
detected using the recently established technique of 16S rRNA
peptide nucleic acid (PNA) fluorescence in situ hybridization
(FISH). Results show that H. pylori can successfully incorporate
within biofilms and its presence was detected for up to five days,
either in the basal layer or inside typical biofilm structures such as
stacks or fronds. The PNA FISH protocol appears to be a promising
new technique for the in situ visualization of microorganisms in
biofilms, especially because the hydrophobic nature of the PNA
molecule allows a better diffusion through the constituents of the
biofilm matrix allowing an improved discrimination of microorganisms
inside these naturally occurring structures. A setback in the
application of this methodology was the presence of
autofluorescent microorganisms. This problem can be minimized by
comparing the morphologic characteristics of these suspected false
positives with typical H. pylori morphology. If questions subsist, the
visualization of the biofilm under different filter blocks can also
improve the degree of certainty in the identification, since the
reporter probe has usually a very distinctive pattern of fluorescence
when compared to the autofluorescent microorganisms
Management of incidental adrenal tumours.
An incidental adrenal tumour, described in this article as an “adrenal incidentaloma,” is an adrenal mass discovered during imaging that was not performed for suspected adrenal disease. These are being detected more frequently in an ageing population through the increased use of computed tomography (eg, computed tomography urogram, or colonoscopy) and magnetic resonance imaging (MRI) scans with enhanced resolution.
This article highlights the management of adrenal incidentalomas, collating recommendations from international guidelines, and is aimed at non-specialists
A fluorescence in situ hybridization method using a peptide nucleic acid probe for the detection of Salmonella spp. in biofilms
A novel peptide nucleic acid (PNA) probe for the detection of Salmonella spp. has been developed. The probe was synthesized and the Alexa Fluor dye 594 was attached to the N-terminus in order to allow detection by fluorescence in situ hybridization (FISH). Specificity and sensitivity probe matching theoretical estimates were both of 100%. The PNA FISH method was optimized, and laboratory testing on representative strains from the Salmonella genus subspecies and several related bacterial species, confirmed the predicted theoretical values of specificity ans sensitivity. Afterwards, the method was successfully adapted to cell detection in suspensions and biofilms. Counterstaining with 4′,6-diamidino-2-phenylindole (DAPI) allowed Salmonella spp. discrimination from heterotrophic consortia of bacteria. However, the direct detection in biofilms presented some limitations for particular types of adhesion materials. These limitations were mainly related with the autofluorescence of the support material at the same wavelength emission as the probe. Nevertheless, this limitation has been overcome by disrupting the biofilm (sonication step) and performing the hybridization on glass slides or in suspension. We hence conclude that PNA FISH represents a reliable tool for biofilm study, allowing specific and direct detection for most support materials, and hence provides spatial organization information for specific groups of microorganisms within mixed/natural biofilms for substrata without a strong autofluorescence signal
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Frailty Assessment in Clinical Practice: Opportunity in the Midst of a Pandemic.
Emerging evidence from studies of older adults hospitalised with COVID-19 suggests that there is a high prevalence of frailty in this patient group. We reflect on the measurement of frailty in older patients hospitalized as an emergency and the translation of frailty from a research to a clinical concept. We consider whether, despite the contemporary challenges in the care of older adults as a result of COVID-19, there are opportunities for care quality improvement during a pandemic.This editorial received no specific funding. Christopher N. Osuafor is supported by the Cambridge British Heart Foundation Centre of Research Excellence (CRE, Centre Code: RE/18/1/34212). Victoria L. Keevil is funded by an MRC/NIHR Clinical Academic Research Partnership Grant (CARP; grant code: MR/T023902/1).The views expressed are those of the authors onl
Maintenance of spiral morphology and formation of biofilms on copper surfaces by water-exposed Helicobacter pylori
There is still a lack of consensus on the way Helicobacter pylori is transmitted, but biofilms in drinking water are suspected to create a safe haven for the subsistence of the bacterium and hence promote a waterborne route of infection. Cultivability in water is low when compared to other waterborne pathogens, a situation that is attributed to the conversion of the highly infectious spiral form to the generally regarded as inactive coccoid form of the bacterium. In this study, the adhesion ability to abiotic surfaces (such as copper and PVC), morphology and cultivability of water-exposed H. pylori was assessed. In copper, the bacterium was able to retain spiral morphology and form 3D structures for over two months whereas in PVC conversion to the coccoid form occurred in approximately 1 week. Even though the logical interpretation for these results would be that copper favours the bacterium survival, standard plating experiments have shown precisely the opposite: cultivability decreases faster for the cells exposed to copper. Besides demonstrating the deleterious action that copper surfaces have on H. pylori, this study also indicates that at least for this case, H. pylori coccoid morphology is in fact a manifestation of cell adaptation to the environment.Fundação para a Ciência e Tecnologia (FCT)
European Commission Research Project SAFER
Characterization of multispecies biofilms by peptide nucleic acid fluorescence in situ hybridization (PNA-FISH)
Our current understanding of biofilms in the environment and in health indicates that these
structures are typically composed of many different microbial species. However, the lack of reliable techniques
for the quantification, visualization and discrimination of each population has meant that studies assessing
multi-species interactions between sessile microorganisms are scarce and low-throughput.
Employing novel peptide nucleic acid fluorescence in situ hybridization (PNA-FISH) methods, we present here
a characterization of Salmonella enterica/Listeria monocytogenes/Escherichia coli single, dual and tri-species
biofilms in seven support materials. Ex-situ, we were able to relate quantitatively the populations of ~56
mixed species biofilms up to 48h, regardless of the support material.In situ a correct quantification remained
more elusive, but a qualitative understanding of biofilm structure and composition is clearly possible for most
support materials. Regarding biological behavior, composition of mixed-culture biofilm seems to be the final
result of competition between microorganisms, both for available nutrients and for free surface to colonize. It is
also suggested that the ability to form biofilm is mostly a species-dependent phenomenon rather than surfacedependent,
as six of the materials maintained both the species profile and had similar total cell numbers. The
exception was copper, that inhibited the biofilm formation for the species tested.
Our findings concluded that, using a single method, such as PNA-FISH, to confidently discriminate multispecies
early-stage biofilms, researchers can infer about spatial organization, intra- or inter-specie interaction and
also assess viable but not cultivable states
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