Staphylococcus aureus in Substrates for Black Soldier Fly Larvae (Hermetia illucens) and Its Dynamics during Rearing.

Black soldier fly larvae (BSFL; Hermetia illucens) are promising insects for the conversion of organic waste streams into valuable biomolecules. Such waste streams can contain foodborne pathogens. To assess this risk factor, this study evaluated the presence of Staphylococcus aureus in waste streams as a substrate ingredient for BSFL production as well as in the rearing process. First, the general microbiological quality and the occurrence of S. aureus were investigated for different waste streams. Staphylococcus aureus was abundantly present. Control of pH and water activity should avoid pathogens, which cannot grow in single-substrate ingredients, redeveloping when mixing streams for optimal substrate conditions for BSFL production. Next, it was investigated whether S. aureus present in the substrate was ingested and/or eradicated by BSFL. In inoculation trials, with S. aureus added to chicken feed as the substrate at 3 or 7 log CFU/g, the larvae showed a reducing effect on S. aureus. After 6 days, S. aureus counts were below the detection limit (2.0 log CFU/g) in all larvae samples and decreased in the substrate to <2.0 and <3.1 log CFU/g for inoculation levels of 3 and 7 log CFU/g, respectively. While this is promising, it is still recommended to monitor and control this pathogen in BSFL rearing. Intriguingly, screening of antimicrobial activity of dominant microorganisms associated with BSFL showed a clear activity of Trichosporon isolates against S. aureus. Future research should explore whether Trichosporon, which is frequently observed in BSFL, plays a role in controlling specific microorganisms, such as S. aureus. IMPORTANCE Given the increasing need for (more sustainable) methods to upcycle organic waste streams, the interest to rear insects, like black soldier fly larvae (BSFL), on such streams is increasing. This study reveals that S. aureus is abundantly present in such waste streams, which might be a point of attention for insect producers. At the same time, it reveals that when S. aureus was inoculated in chicken feed as the substrate, it was not detected in the larvae and was reduced in the substrate after 6 days. Future inoculation trials should investigate whether this reduction is substrate dependent or not. Toward the future, the role of the BSFL microbiota in controlling intestinal bacterial community homeostasis should be explored, because one of the dominant microorganisms associated with BSFL, Trichosporon spp., showed clear activity against S. aureus.

Dynamics of Salmonella inoculated during rearing of black soldier fly larvae (Hermetia illucens).

The black soldier fly is currently the most produced edible insect on industrial scale, with its larval stage being processed into animal feed as the main application. As this insect species enters the feed and food chain, good hygiene and monitoring practices are needed to avoid the entrance of foodborne pathogens via the larvae. However, insufficient data on the risk of such introductions via industrial larvae production are available. To address this gap, a range of rearing trials were conducted in which the substrate, chicken feed, was inoculated with different levels of Salmonella and in which total viable counts and Salmonella counts were determined during the following days. The outgrowth of Salmonella was slower in those experiments with a lower initial contamination level than in experiments with a higher level. No significant reducing effect originating from the larvae on the substrate Salmonella counts was observed, in contrast to previous studies using other substrates. Our study also revealed that airborne transmission of Salmonella is possible under rearing conditions corresponding to those applied at industrial production sites. Based on our results, we recommend insect producers to use substrate ingredients free of Salmonella, and not to count on the antimicrobial activities that BSFL may exert in some situations towards food pathogens. More inoculation studies using other Salmonella serotypes, other zoonotic bacteria, other substrates, larvae of other ages and including variations on rearing protocols are needed in order to obtain a general view on the dynamics of food pathogens in this insect species and to support comprehensive risk assessments.

A uniaxial force and stiffness model of the vagina during laparoscopic sacrocolpopexy.

BACKGROUND: Laparoscopic sacrocolpopexy is the preferred procedure for restoring vaginal vault prolapse. An assistant uses a vaginal manipulator to position and tension the vault such that the surgeon can dissect the bladder, rectum and vault to eventually suture a synthetic mesh used to suspend the vagina to the longitudinal anterior vertebral ligament. Vaginal vault manipulation requires application of high forces for long periods of time. METHODS: This work quantifies the task by measuring and analyzing the interaction forces and the workspace during vaginal vault manipulation. From the measurements we developed a uniaxial model, expressing the increase in interaction force and stiffness of the vagina. By adapting the model parameters, the difference in interaction force and stiffness between moderate and severe prolapse is predicted. FINDINGS: For moderate prolapse the average interaction force and stiffness start at 2.56 N and 0.11 N mm-1 in the tensionfree state, and go up to 20.14 N and 0.53 N mm-1 after complete insertion of the instrument. For severe degrees of prolapse, tissue interaction is much lower starting at 1.68 N and 0.06 N mm-1 while staying limited to 12.20 N and 0.30 N mm-1 at full extension. INTERPRETATION: Population data shows that the stage of prolapse and total vaginal length increase with age and parity. The interaction force and stiffness of the vagina are correlated with this degree of prolapse. By adapting the model parameters a good estimation of the tissue interaction is found for patients with mild and severe prolapse.

Assessing the Microbiota of Black Soldier Fly Larvae (Hermetia illucens) Reared on Organic Waste Streams on Four Different Locations at Laboratory and Large Scale.

This study aimed to gain insight into the microbial quality, safety and bacterial community composition of black soldier fly larvae (Hermetia illucens) reared at different facilities on a variety of organic waste streams. For seven rearing cycles, both on laboratory-scale and in large-scale facilities at several locations, the microbiota of the larvae was studied. Also samples of the substrate used and the residue (= leftover substrate after rearing, existing of non-consumed substrate, exuviae and faeces) were investigated. Depending on the sample, it was subjected to plate counting, Illumina Miseq sequencing and/or detection of specific food pathogens. The results revealed that the substrates applied at the various locations differed substantially in microbial numbers as well as in the bacterial community composition. Furthermore, little similarity was observed between the microbiota of the substrate and that of the larvae reared on that substrate. Despite substantial differences between the microbiota of larvae reared at several locations, 48 species-level operational taxonomic units (OTUs) were shared by all larvae, among which most belonged to the phyla Firmicutes and Proteobacteria. Although the substrate is assumed to be an important source of bacteria, our results suggest that a variety of supposedly interacting factors-both abiotic and biotic-are likely to affect the microbiota in the larvae. In some larvae and/or residue samples, potential foodborne pathogens such as Salmonella and Bacillus cereus were detected, emphasising that decontamination technologies are required when the larvae are used in feed, just as for other feed ingredients, or eventually in food.

Genomic standards consortium projects.

The Genomic Standards Consortium (GSC) is an open-membership community that was founded in 2005 to work towards the development, implementation and harmonization of standards in the field of genomics. Starting with the defined task of establishing a minimal set of descriptions the GSC has evolved into an active standards-setting body that currently has 18 ongoing projects, with additional projects regularly proposed from within and outside the GSC. Here we describe our recently enacted policy for proposing new activities that are intended to be taken on by the GSC, along with the template for proposing such new activities.

Motor neuron disease features in a patient with neuroborreliosis and a cervical anterior horn lesion.

A variety of neurological syndromes has been described in neuroborreliosis: cranial nerve palsies, radiculopathy, axonal neuropathy, stroke, parkinsonism, transverse myelitis, supranuclear palsy, Guillain-Barré syndrome, ... We report a case of neuroborreliosis with cervical myelitis presenting clinically as a lower motor neuron syndrome of the upper and lower limbs with proximal and distal pareses and atrophies as well as bulbar dysarthria and dysphagia. During the course of the disease the patient developed the clinical picture of a meningoencephalitis. After initiating ceftriaxone treatment the patient showed a complete recovery. In endemic regions for Lyme disease, in all neurological syndromes neuroborreliosis has to be excluded.

Errors involved in the existing B-term expressions for the longitudinal diffusion in fully porous chromatographic media Part I: computational data in ordered pillar arrays and effective medium theory.

Numerically solving the effective diffusion in a simplified representation of a chromatographic bed, it was found that the B-term expressions that have up to now been used in the literature, and which can all be reduced to either Deff=(gamma mDm+k'gamma sDs)/(1+k') or Deff=(gamma meDm+k''Dpart)/(1+k''), can no longer be considered to be unconditionally valid. This could be demonstrated by showing that the simulated diffusion data are in agreement with the mathematically sound effective medium theory (EMT), whereas the B-term expressions used up to now in literature are in conflict with the EMT, a theory that is widely accepted in all other fields of science. It is also shown that the use of the existing B-term expressions can lead to very large measurement errors (up to a 100% and more) for the determination of the stationary phase diffusion coefficient gamma sDs from peak parking experiments. The representation of the B-term diffusion should in the future hence be based on the Deff expressions that can be derived from the EMT. These are physically sound and are also more accurate than the classical B-term expressions used up to now.

Guidelines for quality improvement in cardiac surgery. The College of Cardiac Surgery : results of the 2007 survey.

Optimal delivery of health care is a common goal of individual physicians, professional organizations, hospital structures and governmental authorities. A growing concern has emerged from the public, media and third payer organizations concerning the quality of care and the amount of resources spending. In the United States, large databases, guidelines and performance evaluation have been elaborated by medical societies, particularly in the area of cardiac surgery. These tools are useful for improvement of patients' care, resources distribution, pay for performance and public and practitioners' awareness. The evaluation of quality is based on composite models combining structure, process and outcome indices. However, pitfalls such as patients' selection, and risk avoidance in order to improve results must been prevented by adjustment of the treated populations' risk factors by specific scores. The Belgian Health authorities have built a structure directed at delivery of care improvement based on "Care Programs", monitored by Colleges formed by delegates of professional organizations. The College of Cardiac Surgery has promoted several studies aimed at data collection and evaluation. In 2007, a survey was addressed to all the Belgian Cardiac surgeons to define their opinion as to the best indicators of care in their specialty. These results will serve to define further avenues of research. By maintaining the responsibility of care evaluation in the hands of the involved professionals, this kind of cooperation between governmental and physicians' organizations seems to serve the best interests of the public and the practitioners.

On the 3-dimensional effects in etched chips for high performance liquid chromatography-separations.

In an attempt to quantify the potential of photolithographically etched micro-pillar arrays as a perfectly ordered alternative for the packed bed of spheres, the additional band broadening originating from the top and bottom plate has been investigated using computational fluid dynamics simulations. These calculations provide insight in the theoretical expectations that can be made for the experimental work that is currently being conducted by a number of groups. The calculations show that the additional band broadening contribution can be expected to go through a transient regime as a function of the axial distance along the array. In its fully developed regime and in the most relevant velocity range, the top and bottom wall contribution almost doubles the band broadening compared to the band broadening in a perfectly ordered array of non-porous, non-retentive pillars without top and bottom wall. Compared to the band broadening in an array of porous, retentive pillars on the other hand, the top and bottom wall-effect can be expected to become negligible. A simplified, phenomenological model yielding a first principles prediction of both the transient and the steady-state top and bottom wall band broadening as a function of the inter-pillar distance and the pillar height is proposed and shows good qualitative agreement with the exact calculations.

[Sudden onset of hemoptysis during (coil) embolization of a Swan-Ganz catheter induced pseudoaneurysm of the pulmonary artery]. / Survenue d'une hémorragie bronchique lors de l'embolisation d'un pseudo-anévrysme pulmonaire consécutif a un cathétérisme par Swan-Ganz.

We report the embolization of a pulmonary artery pseudoaneurysm consecutive to Swan-Ganz catheterization. Embolization was successful despite an iatrogenic rupture and a massive hemoptysis.

On the optimisation of the bed porosity and the particle shape of ordered chromatographic separation media.

We report on a theoretical study wherein we considered a large number of ordered two-dimensional porous pillar arrays with different pillar shapes and widely varying external porosity and calculated the flow resistance and the band broadening (under retentive conditions) over the complete range of practical velocities using a commercial computational fluid dynamics software package. It is found that the performance of the small porosity systems is very sensitive to the exact pillar shape, whereas this difference gradually disappears with increasing porosity. The obtained separation impedances are very small in comparison to packed bed and monolithic columns and decrease with increasing porosity. If accounting for the current micromachining limitations, a proper selection of the exact shape and porosity even becomes more critical, and different design rules are obtained depending on whether porous or non-porous pillars are considered.

Influence of the pillar shape on the band broadening and the separation impedance of perfectly ordered 2-D porous chromatographic media.

We report on a computational study assessing the effect of the pillar shape in perfectly ordered porous chromatographic media. Using computational fluid dynamics to compare the band broadening and flow resistance characteristics of a large number of different pillar shapes, it is found that the most axially elongated shapes yield the best chromatographic performance and that diamonds are to be preferred over ellipsoids. The former pack into a more uniform pore space and display a smaller C(s) value, whereas the latter pack into a locally constricted pore space and therefore generate a considerably larger flow resistance. For the presently considered case of a densely packed array (epsilon = 0.4), changing the pillar shape from a cylinder to a more elongated diamond, for example, reduces the minimal plate heights from h(min) = 0.84 to h(min) = 0.72, the C factor from C = 0.062 to C = 0.050, and the separation impedance from E(min) = 330 to E(min) = 220, without affecting the number of interchannel coupling points.

Computational study of the band broadening in two-dimensional etched packed bed columns for on-chip high-performance liquid chromatography.

The chromatographic performance of several straightforward two-dimensional etched packed bed column lay-outs (equilaterally staggered arrays of, respectively, circular, hexagonal, and diamond-like pillars) has been compared using commercial computational fluid dynamics software. In all cases, the bed porosity was kept at epsilon = 0.4 and a retained component with zone capacity ratio k" = 2 was considered. Exploring the use of six different possible characteristic dimensions to bring the Van Deemter plots of the three different considered particle shapes into agreement, none of them yielded a perfect agreement. Using the pillar volume-based equivalent cylinder diameter (deq) as the characteristic dimension, the diamond-like pillars yielded a significantly smaller h(min) value than the cylinders and the hexagons (h(min) approximately equal to 0.74 for the former versus h(min) approximately equal to 0.83 for the two latter). Including the flow resistance into the analysis, it was found that the "hydrodynamic" shape of the particles has an important influence on the separation impedance E. The more axially elongated diamond pillars yielded an Emin number as small Emin = 180 (for a retained component with k" = 2), i.e. about 40% smaller than the cylinders and the hexagons (Emin = 300-330). The obtained h(min) and Emin values are also significantly smaller than the values often cited for the best possible packed bed HPLC columns. We believe this is a consequence of the assumed perfect homogeneity of the etched structures, and hence hints at the potential benefits of perfectly ordered chromatographic columns, as was already inferred by Knox [J. Chromatogr. A 831 (1999) 3; 960 (2002) 7] and He et al. [Anal. Chem. 70 (1998) 3790].

[The heart surgery department]. / Le Service de Chirurgie Cardiaque.

The initial development of cardiac surgery at Erasme Hospital was closely related to the achievements in thoracic organ transplantation, with numerous synergies between other clinical and research units of the Faculty of Medicine. New advances in biology and biotechnology have met the challenges of modern cardiology, in the fields of advanced heart failure, refractory angina, rhythm disturbances or minimally invasive surgery. Fundamental aspects of clinical practice have been the subject of laboratory investigations, resulting in fruitful interactions and promising scientific outlooks.

Conversion from ministernotomy to full sternotomy in aortic valve replacement.

Conversion (C) from ministernotomy (M.S.) to full sternotomy was necessary in 5% of the cases in a series of 100 patients consecutively operated for Aortic Valve Replacement (A.V.R.) Analysis of the demographics and surgical techniques indicate older age, aortic fragility, diffuse coronary disease, chronic renal failure and left vent insertion as contributing factors. Despite increased operative blood losses, extra-corporeal circulation (E.C.C.) times, intensive care unit (I.C.U.) stay and hospital stay, no mortality was observed in the conversion group, as compared to 4.2% mortality in the total ministernotomy (MS) population. Preoperative patients selection, avoidance of technical pitfalls, and knowledge of alternative surgical measures are suggested to further decrease the incidence of conversions.

[Extensive intramural hematoma of the thoracic aorta]. / Hématome intramural extensif de l'aorte thoracique.

A[TRACE;del] 53-year-old hypertensive patient presenting with acute chest pain was found to have an intramural haematoma (IMH) of both ascending and descending aorta associated with a 6 cm ascending fusiform aortic aneurysm. Six weeks of antihypertensive treatment allowed complete resolution of the intramural haematoma of the descending aorta. Limited surgical repair of the ascending aorta by Gore-Tex graft prosthesis interposition was then performed. The patient was in good health with a one-year follow-up.

Unilateral pallidotomy in PD: a controlled study of cognitive and behavioral effects. The Netherlands Pallidotomy Study (NEPAS) group.

OBJECTIVE: To investigate whether unilateral pallidotomy affects cognitive and behavioral functioning. METHODS: At baseline and after 6 months we assessed neuropsychological functioning in 35 patients with advanced PD. After baseline examination, patients were randomized to pallidotomy within 1 month (6 left-sided, 13 right-sided) or to pallidotomy after follow-up assessment 6 months later (n = 16; control group). We performed neuropsychological tests of language, visuospatial function, memory, attention, and executive functions. Self ratings and proxy ratings of memory problems and dysexecutive symptoms were also collected. RESULTS: No significant differences over time were found between pallidotomy and control groups, with the exception of a decrease of verbal fluency in the left-sided pallidotomy group. CONCLUSIONS: Unilateral pallidotomy is relatively safe with respect to cognition and behavior. Left-sided pallidotomy may lead to minor deterioration in verbal fluency. The sample size of this study is too small, however, to rule out the possibility of infrequent but clinically important side effects.

[Role of transesophageal echocardiography in the diagnosis of pulmonary embolism]. / Apport de l'échographie cardiaque transoesophagienne au diagnostic d'embolie pulmonaire.

The authors report a 72 year-old woman presenting with severe shock after ilio-femoral artery bypass surgery. The transesophageal echocardiography allowed the diagnosis of an unsuspected massive right pulmonary artery embolism. This case emphasizes the role of this procedure for the early bedside diagnosis of massive pulmonary embolism, especially in critically ill patients who require urgent therapeutic interventions.

Candida albicans septic thrombosis of the right atrium is associated with a central venous catheter.

Right atrial thrombus formation is a rare complication of central venous catheterization in adults. Infection of this thrombus is exceptional. A case of a right atrial thrombus associated with Candida albicans infection is described. Surgical thrombectomy, withdrawal of the catheter, and long-term antiinfectious therapy seem the only appropriate treatment. The literature on this unusual condition is reviewed.