Tracking the sources of psychrotrophic bacteria contaminating chicken cuts during processing.

The major aim of the study was to establish the routes via which spoilage associated psychrotrophic bacteria contaminate poultry products at a large processing plant located in Belgium. Environmental samples were collected consisting of samples of air and swabs of food contact surfaces. Product samples were also collected consisting of modified atmosphere packaged (MAP) chicken wings and legs, which were analyzed microbiologically on the same day they were produced as well as after their sell-by date. Psychrotrophic bacteria from these samples were subsequently clustered and identified by means of MALDI-TOF MS and 16S rRNA gene sequencing. Carnobacterium maltaromaticum was determined to dominate the spoilage flora of both wings and legs. Other psychrotrophic bacteria able to grow on MRS which were identified on expired wings and legs included Carnobacterium divergens, Brocothrix thermosphacta, Lactobacillus curvatus, and Lactobacillus brevis. These were determined to arise from food contact surfaces such as cutting blades, leg hooks, Ertalon and polyurethane conveyor belts, working tables, and the hands of the operators. Importantly, it was determined that cleaning and disinfection was largely inadequate. Air was also determined to be an important vector of psychrotrophic bacteria in the processing environment, potentially contaminating the products directly or indirectly.

Temporal and Spatial Distribution of the Acetic Acid Bacterium Communities throughout the Wooden Casks Used for the Fermentation and Maturation of Lambic Beer Underlines Their Functional Role.

Few data have been published on the occurrence and functional role of acetic acid bacteria (AAB) in lambic beer production processes, mainly due to their difficult recovery and possibly unknown role. Therefore, a novel aseptic sampling method, spanning both the spatial and temporal distributions of the AAB and their substrates and metabolites, was combined with a highly selective medium and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) as a high-throughput dereplication method followed by comparative gene sequencing for their isolation and identification, respectively. The AAB (Acetobacter species more than Gluconobacter species) proliferated during two phases of the lambic beer production process, represented by Acetobacter orientalis during a few days in the beginning of the fermentation and Acetobacter pasteurianus from 7 weeks until 24 months of maturation. Competitive exclusion tests combined with comparative genomic analysis of all genomes of strains of both species available disclosed possible reasons for this successive dominance. The spatial analysis revealed that significantly higher concentrations of acetic acid (from ethanol) and acetoin (from lactic acid) were produced at the tops of the casks, due to higher AAB counts and a higher metabolic activity of the AAB species at the air/liquid interface during the first 6 months of lambic beer production. In contrast, no differences in AAB species diversity occurred throughout the casks.IMPORTANCE Lambic beer is an acidic beer that is the result of a spontaneous fermentation and maturation process. Acidic beers are currently attracting attention worldwide. Part of the acidity of these beers is caused by acetic acid bacteria (AAB). However, due to their difficult recovery, they were never investigated extensively regarding their occurrence, species diversity, and functional role in lambic beer production. In the present study, a framework was developed for their isolation and identification using a novel aseptic sampling method in combination with matrix-assisted laser desorption ionization-time of flight mass spectrometry as a high-throughput dereplication technique followed by accurate molecular identification. The sampling method applied enabled us to take spatial differences into account regarding both enumerations and metabolite production. In this way, it was shown that more AAB were present and more acetic acid was produced at the air/liquid interface during a major part of the lambic beer production process. Also, two different AAB species were encountered, namely, Acetobacter orientalis at the beginning and Acetobacter pasteurianus in a later stage of the production process. This developed framework could also be applied for other fermentation processes.

The wrong end of the telescope: neuromuscular mimics of movement disorders (and vice versa).

The rapid advances in modern neurology have led to increased specialisation in clinical practice. Being an expert in a neurology subspecialty offers advantages for diagnosing and managing specific disorders. However, specialisation also risks tunnel vision: interpreting symptoms and signs within one's own framework of reference, while ignoring differential diagnostic options from other subspecialties. This is particularly relevant when the patient's presentation potentially belongs to different neurological subspecialties. We illustrate this challenge by highlighting a series of clinical features that partially overlap between two common subspecialties: movement disorders and neuromuscular disorders. An overlap in clinical presentation is not rare, and includes, for example, involuntary eyelid closure (which could be active eye closure due to blepharospasm, or ptosis due to weakness). Other overlapping features include abnormal postures, involuntary movements and gait changes. We describe two of these overlapping features in more detail and emphasise the possible consequences of 'looking through the wrong end of the telescope' in such patients, as this may lead to a wrong differential diagnosis, unnecessary investigations and a delayed treatment start.

Surgical management of gastrointestinal stromal tumours: a single centre experience during the past 17 years.

BACKGROUND: Gastrointestinal stromal tumour (GIST) is a rare tumour that can arise anywhere within the gastrointestinal tract. OBJECTIVES: Our objective was to present our experience managing this rare tumour of the gastrointestinal tract. We reviewed the clinico-pathological and morphological features, our experience with surgical treatment, and the outcome GIST in our centre. PATIENTS AND METHODS: The current retrospective analysis included 64 patients with GIST observed between February 1995 and September 2012. RESULTS: There were 39 males and 25 females. The mean age was 63.2 (range 36-83). The GISTs were located in the stomach in the majority of patients (60 patients, 94.0%). The tumour was asymptomatic in 14 (21.9%) patients. The tumour size varied from 0.4 to 25 cm with a mean size of 7.9 cm. Five patients showed peritoneal or liver metastasis at diagnosis. All patients had surgery. Five patients had a R2 resection and in one patient the resection-free margin was uncertain. In our cohort we had 5 patients with metastasis at diagnosis who received adjuvant imatinib. Four patients developed metastasis in the follow-up period. Three patients died due to GIST, three other patients died due to other disease. CONCLUSIONS: Gastric GIST were more common than GIST at other locations. Surgical treatment was the main therapeutic option. Tyosine kinase receptor inhibitors was used as a first line treatment in patients with metastatic GISTs or in patients with recurrence of the disease.

Position statement on how can we can implement the Greendeal in our gastrointestinal and gastrointestinal endoscopy department in Belgium.

The importance to reach the target to be carbon net zero by 2050, as presented by the European Commission in the European Green Deal, cannot be overestimated. In a current endoscopy world, where single use has found its place and techniques are constantly evolving, it will be a challenge to reach these goals. How can we reconcile this evolution to a carbon neutral status by 2050 without compromising patients care, clinical standards and training needs? The European Society of Gastrointestinal Endoscopy (ESGE) together with the European Society of Gastroenterology and Endoscopy Nurses and Associates (ESGENA) recently published a position statement (1) whereas in the UK there is the work from the green endoscopy group (2) in line with the strategy of the British Society of Gastroenterology (BSG) on sustainability (3). In Flanders, a project called "greendeal in duurzame zorg" had its kick off in March 2023 (4) so it is about time that we in Belgium, as gastroenterologists, start with tangible actions to a more sustainable daily practice. We wrote this position statement in cooperation with the Vlaamse Vereniging voor Gastro-Enterologie (VVGE), the Société royale belge de Gastro-entérologie (SRBGE) and the Belgian Society of Gastrointestinal Endoscopy (BSGIE). We will also work together in the coming years to continue to motivate our members to work on these initiatives and to co-opt new projects within the framework of the greendeal.

Estimating the force of infection for HCV in injecting drug users using interval-censored data.

Injecting drug users (IDUs) account for most new HCV infections. The objectives of this study were: to estimate the force of infection for hepatitis C virus in IDUs within the interval-censoring framework and to determine the impact of risk factors such as frequency of injection, drug injected, sharing of syringes and time of first injection on the time to HCV infection. We used data from the Amsterdam Cohort Study collected in The Netherlands and focused on those individuals who were HCV negative upon entry into the study. Based on the results, the force of infection was found to vary with time of first injection. The risk of infection was higher in the first 3 years of an IDU's career, implying estimates based on single cross-sectional studies could be biased. Frequency of injection and type of drug injected were found to be highly significant predictors, whereas sharing syringes was not.

Validation of MALDI-TOF MS for rapid classification and identification of lactic acid bacteria, with a focus on isolates from traditional fermented foods in Northern Vietnam.

AIMS: To evaluate the potential use of MALDI-TOF MS for fast and reliable classification and identification of lactic acid bacteria (LAB) from traditional fermented foods. METHODS AND RESULTS: A total of 119 strains of LAB from fermented meat (nem chua) were analysed with both (GTG)(5)-PCR fingerprinting and MALDI-TOF MS. Cluster analysis of the profiles revealed five species represented by a single isolate both in (GTG)(5)-PCR and in MALDI-TOF MS; five species grouped alike for (GTG)(5)-PCR and for MALDI-TOF MS; however, differences in minimal similarity between the delineated (GTG)(5)-PCR and MALDI-TOF MS clusters could be observed; three species showed more heterogeneity in their MALDI-TOF MS profiles compared to their (GTG)(5)-PCR profiles; two species, each represented by a single MALDI-TOF cluster, were subdivided in the corresponding (GTG)(5)-PCR dendrogram. As proof of the identification potential of MALDI-TOF MS, LAB diversity from one fermented mustard sample was analysed using MALDI-TOF MS. PheS gene sequencing was used for validation. CONCLUSIONS: MALDI-TOF MS is a powerful, fast, reliable and cost-effective technique for the identification of LAB associated with the production of fermented foods. SIGNIFICANCE AND IMPACT OF THE STUDY: Food LAB can be identified using MALDI-TOF MS, and its application could possibly be extended to other food matrices and/or other food-derived micro-organisms.

Cerebrospinal fluid tau and phosphorylated tau protein are elevated in corticobasal syndrome.

Differentiating corticobasal syndrome (CBS) from progressive supranuclear palsy (PSP) and idiopathic Parkinson's disease (PD) can be difficult. To investigate the additional value of cerebrospinal fluid (CSF) biomarkers in the diagnostic differentiation of parkinsonism, we analyzed the CSF concentrations of total protein, lactate and brain specific proteins amyloid-ß(42) protein, tau protein (t-tau), and tau protein phosphorylated at Thr181 (p-tau), in CSF samples from patients with PSP (n = 21), CBS (n = 12), and PD (n = 28). CBS patients demonstrated higher concentrations of t-tau and p-tau compared with PSP and PD patients. In discriminating CBS and PD, t-tau offered the best combination of sensitivity (75%) and specificity (90.9%), followed by p-tau (sensitivity 87.5% and specificity 75%). The p-tau/t-tau ratio resulted in sensitivity of 84.2% and specificity of 66.7% in discriminating PSP and CBS. In conclusion, our results suggest that CSF parameters are of additional value in the diagnostic differentiation of CBS and PD.

Insights into the venom composition of the ectoparasitoid wasp Nasonia vitripennis from bioinformatic and proteomic studies.

With the Nasonia vitripennis genome sequences available, we attempted to determine the proteins present in venom by two different approaches. First, we searched for the transcripts of venom proteins by a bioinformatic approach using amino acid sequences of known hymenopteran venom proteins. Second, we performed proteomic analyses of crude N. vitripennis venom removed from the venom reservoir, implementing both an off-line two-dimensional liquid chromatography matrix-assisted laser desorption/ ionization time-of-flight (2D-LC-MALDI-TOF) mass spectrometry (MS) and a two-dimensional liquid chromatography electrospray ionization Founer transform ion cyclotron resonance (2D-LC-ESI-FT-ICR) MS setup. This combination of bioinformatic and proteomic studies resulted in an extraordinary richness of identified venom constituents. Moreover, half of the 79 identified proteins were not yet associated with insect venoms: 16 proteins showed similarity only to known proteins from other tissues or secretions, and an additional 23 did not show similarity to any known protein. Serine proteases and their inhibitors were the most represented. Fifteen nonsecretory proteins were also identified by proteomic means and probably represent so-called 'venom trace elements'. The present study contributes greatly to the understanding of the biological diversity of the venom of parasitoid wasps at the molecular level.

Seventy-five years of estimating the force of infection from current status data.

The force of infection, describing the rate at which a susceptible person acquires an infection, is a key parameter in models estimating the infectious disease burden, and the effectiveness and cost-effectiveness of infectious disease prevention. Since Muench formulated the first catalytic model to estimate the force of infection from current status data in 1934, exactly 75 years ago, several authors addressed the estimation of this parameter by more advanced statistical methods, while applying these to seroprevalence and reported incidence/case notification data. In this paper we present an historical overview, discussing the relevance of Muench's work, and we explain the wide array of newer methods with illustrations on pre-vaccination serological survey data of two airborne infections: rubella and parvovirus B19. We also provide guidance on deciding which method(s) to apply to estimate the force of infection, given a particular set of data.

BSGIE survey on COVID-19 and gastrointestinal endoscopy in Belgium : results and recommendations.

BACKGROUND AND AIMS: With the first wave of the COVID-19 pandemic declining, activities in the gastrointestinal clinic are being recommenced after a period of stringent measures. Since a second COVID-19 wave is not entirely ruled out health care professionals might remain faced with the need to perform endoscopic procedures in patients with a confirmed positive or unknown COVID-19 status. With this report we aim to provide a practical relevant overview of preparation and protective measures for gastroenterologists based on the currently available guidelines and our local experience and results of a national Belgian survey, to guarantee a fast recall of an adequate infection prevention if COVID-19 reoccurs. METHODS: From the 23rd of March 2020 and the 13th of May 2020 we performed a Pubmed, Embase and Medline search, resulting in 37 papers on COVID-19 and endoscopy. Additionally, we combined these data with data acquired from the national BSGIE survey amongst Belgian gastroenterologists. RESULTS: Based on 72 completed surveys in both university and non-university hospitals, the results show (1) a dramatic (<20%) or substantial (<50%) decrease of normal daily endoscopy in 74% and 22% of the units respectively, (2) a difference in screening and protective measures between university and non-university hospitals. These findings were subsequently compared with the current guidelines. CONCLUSION: Based on new data from the BSGIE survey and current guidelines we tried to realistically represent the current COVID-19 trends in protective measures, screening and indications for endoscopy and to provide a practical overview as preparation for a possible second wave.

Impact of a short period of pre-enrichment on detection and bacterial loads of methicillin-resistant Staphylococcus aureus from screening specimens.

We compared the impacts of direct plating on a chromogenic medium and of plating after enrichment (4 h and overnight) on the detection of methicillin-resistant Staphylococcus aureus (MRSA) from 52 patient screening samples. MRSA colony counts for approximately 70% of samples after overnight pre-enrichment were >20-fold higher than the counts after the other two treatments. The qualitative differences (sample was MRSA positive/negative) between the results of the direct plating and 4-h pre-enrichment treatments were not significant, indicating no advantage of the latter; however, the number of samples positive for MRSA increased significantly after an overnight sample pre-enrichment (P < 0.005).

The correlated and shared gamma frailty model for bivariate current status data: an illustration for cross-sectional serological data.

Frailty models are often used to study the individual heterogeneity in multivariate survival analysis. Whereas the shared frailty model is widely applied, the correlated frailty model has gained attention because it elevates the restriction of unobserved factors to act similar within clusters. Estimating frailty models is not straightforward due to various types of censoring. In this paper, we study the behavior of the bivariate-correlated gamma frailty model for type I interval-censored data, better known as current status data. We show that applying a shared rather than a correlated frailty model to cross-sectionally collected serological data on hepatitis A and B leads to biased estimates for the baseline hazard and variance parameters.

Establishing the spread of bluetongue virus at the end of the 2006 epidemic in Belgium.

Bluetongue (BT) was notified for the first time in several Northern European countries in August 2006. The first reported outbreaks of BT were confirmed in herds located near the place where Belgium, The Netherlands and Germany share borders. The disease was rapidly and widely disseminated throughout Belgium in both sheep and cattle herds. During the epidemic, case reporting by the Veterinary Authorities relied almost exclusively on the identification of herds with confirmed clinical infected ruminants. A cross-sectional serological survey targeting all Belgian ruminants was then undertaken during the vector-free season. The first objective of this study was to provide unbiased estimates of BT-seroprevalence for different regions of Belgium. Since under-reporting was suspected during the epidemic, a second goal was to compare the final dispersion of the virus based on the seroprevalence estimates to the dispersion of the confirmed clinical cases which were notified in Belgium, in order to estimate the accuracy of the case detection based on clinical suspicion. True within-herd seroprevalence was estimated based on a logistic-normal regression model with prior specification on the diagnostic test's sensitivity and specificity. The model was fitted in a Bayesian framework. Herd seroprevalence was estimated using a logistic regression model. To study the linear correlation between the BT winter screening data and the case-herds data, the linear predicted values for the herd prevalence were compared and the Pearson correlation coefficient was estimated. The overall herd and true within-herd seroprevalences were estimated at 83.3 (79.2-87.0) and 23.8 (20.1-28.1)%, respectively. BT seropositivity was shown to be widely but unevenly distributed throughout Belgium, with a gradient decreasing towards the south and the west of the country. The analysis has shown there was a strong correlation between the outbreak data and the data from the survey (r=0.73, p<0.0001). The case detection system based on clinical suspicion underestimated the real impact of the epidemic, but indicated an accurate spatial distribution of the virus at the end of the epidemic.

Impact of human interventions on the spread of bluetongue virus serotype 8 during the 2006 epidemic in north-western Europe.

Bluetongue virus (BTV) can be spread by movement or migration of infected ruminants. Infected midges (Culicoides sp.) can be dispersed with livestock or on the wind. Transmissions of infection from host to host by semen and trans-placental infection of the embryo from the dam have been found. As for any infectious animal disease, the spread of BTV can be heavily influenced by human interventions preventing or facilitating the transmission pathways. This paper describes the results of investigations that were conducted on the potential role of the above-mentioned human interventions on the spread of BTV-8 during the 2006 epidemic in north-western Europe. Data on surveillance and control measures implemented in the affected European Union (EU) Member States (MS) were extracted from the legislation and procedures adopted by the national authorities in Belgium, France, Germany, and The Netherlands. The impact of the control measures on the BTV-incidence in time and space was explored. Data on ruminant transports leaving the area of first infection (AFI) to other areas within and beyond the affected MS were obtained from the national identification and registration systems of the three initially affected MS (Belgium, Germany, The Netherlands) and from the Trade Control and Expert System (TRACES) of the European Commission. The association between the cumulative number of cases that occurred in a municipality outside the AFI and the number of movements or the number of animals moved from the AFI to that municipality was assessed using a linear negative binomial regression model. The results of this study indicated that the control measures which were implemented in the affected MS (in accordance with EU directives) were not able to fully stop further spread of BTV and to control the epidemic. This finding is not surprising because BT is a vector-borne disease and it is difficult to limit vector movements. We could not assess the consequences of not taking control measures at all but it is possible, if not most likely, that this would have resulted in even wider spread. The study also showed an indication of the possible involvement of animal movements in the spread of BTV during the epidemic. Therefore, the prevention of animal movements remains an important tool to control BTV outbreaks. The extension of the epidemic to the east cannot be explained by the movement of animals, which mainly occurred in a north-western direction. This indicates that it is important to consider other influential factors such as dispersal of infected vectors depending on wind direction, or local spread.

Techniques for the placement of hepatic artery catheters for regional chemotherapy in unresectable liver metastases.

AIMS: For patients with unresectable liver metastases from colorectal cancer (CRC), hepatic artery infusion chemotherapy (HAIC) can produce higher response rates as compared to systemic chemotherapy. However, the added morbidity and early dysfunction after catheter placement have negatively influenced the outcomes of randomized studies. METHODS: Between July 1998 and March 2006, 29 patients with unresectable liver metastases from CRC were included in three different HAIC protocols. A catheter was laparoscopically placed in the gastroduodenal artery, retrograde to the common hepatic artery and was attached to a subcutaneous access port. Perioperative parameters and catheter-associated adverse events during chemotherapy were studied. RESULTS: Mean operating time was 106+/-29 min and median duration of hospitalization was 2 days (range: 1-13). No major perioperative complications occurred but there was 1 death (3.6%) 1 week after surgery due to hemorrhagic shock after necrosis and rupture of the hepatic artery. During a median follow-up of 10 months (range: 0-35) we observed 5 (17%) catheter-associated adverse events, but in only 2 patients (7%) this resulted in a loss of catheter function before the end of chemotherapy. Overall median duration of HAIC was 8 months (range: 1-28). CONCLUSION: Laparoscopic placement of a hepatic artery catheter is associated with a low operative morbidity. The observed functionality of the hepatic artery ports in our series is encouraging for the use in future studies of HAIC.

Risk factors for bovine herpesvirus-1 seropositivity.

This paper reports the investigation of risk factors for bovine herpesvirus-1-seropositivity, based on a cluster-sample survey of the Belgian cattle population. This serosurvey was carried out in 1998 in 309 randomly selected unvaccinated herds of all types (dairy, mixed and beef) were all bovids (N = 11,284) were sampled. Older and male cattle had higher seroprevalence. Origin (homebred or purchased) and herd size interacted; for smaller herds (< or = 50 cattle on the premises), purchase status and larger herd size were risk factors, whereas these effects were not observed for larger herds.

The social contact hypothesis under the assumption of endemic equilibrium: Elucidating the transmission potential of VZV in Europe.

The basic reproduction number R0 and the effective reproduction number R are pivotal parameters in infectious disease epidemiology, quantifying the transmission potential of an infection in a population. We estimate both parameters from 13 pre-vaccination serological data sets on varicella zoster virus (VZV) in 12 European countries and from population-based social contact surveys under the commonly made assumptions of endemic and demographic equilibrium. The fit to the serology is evaluated using the inferred effective reproduction number R as a model eligibility criterion combined with AIC as a model selection criterion. For only 2 out of 12 countries, the common choice of a constant proportionality factor is sufficient to provide a good fit to the seroprevalence data. For the other countries, an age-specific proportionality factor provides a better fit, assuming physical contacts lasting longer than 15 min are a good proxy for potential varicella transmission events. In all countries, primary infection with VZV most often occurs in early childhood, but there is substantial variation in transmission potential with R0 ranging from 2.8 in England and Wales to 7.6 in The Netherlands. Two non-parametric methods, the maximal information coefficient (MIC) and a random forest approach, are used to explain these differences in R0 in terms of relevant country-specific characteristics. Our results suggest an association with three general factors: inequality in wealth, infant vaccination coverage and child care attendance. This illustrates the need to consider fundamental differences between European countries when formulating and parameterizing infectious disease models.