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AZ Zeno

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Abstract Bachelor Project MLT 2020-2021Implementatie van macrocoupes in een laboratorium voor pathologische anatomie: effect op diagnostiek van prostaatkanker

When a prostatectomy is performed and is to be examined by a pathologist, the tissue is cut up in standard sections and placed in twenty to twenty-five cassettes per prostatectomy specimen. This is not only time-consuming and less sustainable, but also complicates diagnosis. The microscopic image is fragmented because of the many incisions that are made. In addition, the hospital has been utilizing robot-assisted surgery to perform prostatectomies since 2019. As a result, more prostatectomy specimens are surgically removed and examined, thus increasing the previously raised issues of fragmentation and increased workload. Since two years the Pathology department has been utilizing a new technique called macro-embedding through which whole-mount sections are cut.

The aim of this study is to evaluate how this new technique affects three specific areas. Firstly, the effect on the laboratory as a whole, secondly the effect on a diagnostic level and lastly to examine whether there is a correlation between MRI and the microscopic images obtained through whole-mount sections.

The effect on the laboratory as a whole is examined through evalution of the tissue processing steps. The effect on a diagnostic level is assessed by comparing twenty-nine cases dated between 2016 and 2021. The correlation between radiology and pathology is examined by comparing nine cases.

Examining the effect on the laboratory as a whole resulted in two important advantages, namely time-saving and a reduced workload. When examining the effect on a diagnostic level, it appears that whole-mount sections provide a better assessment of the tumor site. Lastly, comparing nine cases showed there was indeed a correlation between radiology and pathology, meaning both the diagnosis of the pathologist and radiologist coincide.

In conclusion, it can be stated that the use of whole-mount sections is not only time-saving but also beneficial concerning the diagnostics, since the tissue is not fragmented by several incisions.


Abstract Bachelor Project MLT 2018-2019Identification of dermatophytes and filamentous fungi with Maldi-TOF MS: evaluation of the ID Fungi plates (Conidia, France)

Filamentous fungi and dermatophytes are a common pathogen for humans. Identification of these fungi is necessary to give the best treatment. However, the results are not always trustworthy, the MALDI-TOF MS is a tool often used to help the biologist identify these fungi. The problem is the culture plate that is used to let them grow on Sabouraud agar is most used plate to let fungi grow on. The fungi are scrapped off the plate and are taken for a protein extraction. Scrapping these fungi off the plate is very difficult since the protein extraction fails, if you also have scrapped off some components of the plate itself.

The new ID Fungi plates, invented by Conidia, offer a simple solution to this problem. The plate has a membrane on it. The fungi can still grow, due the transport of nutrients trough the membrane. Scrapping off the fully grown fungi is also very easy, and faster, since you can’t scrape off components of the plate. That is why the protein extraction should be more successful instead of using the Sabouraud agar. The MALDI-TOF MS is only used for the creation of the spectra of the fungi. A new web application made by BCCM/IHEM is used to compare the spectra with the spectra in the database.

The two plates were compared. 29 samples were grown on both plates and identified. 10,3 % (three samples) were not able to be identified using the ID Fungi plates, while the double of the samples tested on SAB-agar couldn’t be identified. 79,3 % were correctly identified on genus and species level when grown on a ID Fungi plate, while only 65,5 % was correctly identified on both genus and species level when grown on a Sabouraud agar. The other fungi respectively 10,3 % and 13,8 % were only identified on genus level by the ID Fungi plate and the Sabouraud agar. three samples were not fully grown on the ID Fungi plate. That’s probably why they failed to be identified.

The new ID Fungi plates are more accurate in identifying fungi then the Sabouraud agar. They are a lot easier to be used for the protein extraction, which saves some time. Further studies could be used to determine how long fungi should be incubated, to get a higher possibility of identification.


Abstract bachelorproef 2016-2017Implementing internal audits in a surgical pathology laboratory

The purpose of this paper is implementing internal audits in a surgical pathology laboratory. These audits are required for the new Belgian law about the quality system in surgical pathology laboratories. The law required that internal audits need to be conducted for all the paragraphs in the praktijkrichtlijn, within a timespan of five years. No internal audits where conducted for the first three years because of management changes and the work that needed to be done to the quality system.  An external audit was performed to get an idea of the current situation of the quality system.

For the implementation, personnel have to be formally authorized to conduct internal audits. This can be done with internal or external education. A five-year audit plan needs to be crafted, preferably a plan that can be used as a template for the upcoming years. The procedure for internal audits must be developed. This must happen within the boundaries of the law. The first audits need to be conducted and evaluated. Finely, the corrective measures need to be arranged and followed. All these steps must be well documented and archived so progress of the audits can be checked.

All personnel follow a supplementary training and half of the personnel is now fully authorized to conducted internal audit, with the other half soon to follow. Two five-year audit plans are made. The first one is a short-term planning, the audits that need to be conducted in five years are now done in 2 years. The second planning is made so it can be used as a template for the upcoming years. The procedure for internal audits is written and was succesfully used in both internal audits. The audits found a large non-conformity in the system and did this without interrupting the workflow too much. The corrective measures are drawn-up for the first audit but could not be followed-up because of the time limit of this paper.

The implementation of the internal audits at the surgical pathology laboratory of AZ Zeno is successful. All personnel are authorized to conduct internal audits or will be in the first few months. A functional template was made for the required five-year audit plan. The procedure doesn’t disrupt the workflow too much. The effectiveness of the audits is proven by the non-conformities that are found and corrected. The corrective measures are drawn-up but the full cycle of the internal audits would need to be evaluated in a few years.

Abstract bachelorproef 2015-2016Prevalentie van Clostridium difficile bij bewoners van Woon- en Zorgcentra aan de Oostkust van België

The aim of the study was to determine the prevalence of Clostridium difficile carriers within the residents of the WZC in our region.

Asymptomatic C. difficile colonization is the condition where in C. difficile is detected in the absence of symptoms. It is assumed that most of these carriers are protected against progression to a real infection by a humoral response against the toxins. However, they can act as a reservoir and can pose a risk to other persons. The primary routes of transmission are the faecal-oral route and direct contact with contaminated surfaces. (Furuya- Kanamori et al., 2015)

Obviously, in the nursing home population group a lot of people carry one or more risks. For this reason, this study was also set up. In the opinion of the Superior Health Council 8365, May 2008, states that the prevalence of C. difficile infection in Nursing homes varies between 2.1 and 8.1% (Simor et al., 1993).

Another recent study in Germany shows a prevalence of carriage of between 0 and 10 % between the various Nursing Homes (Arvand et al., 2011).

A letter of participation was sent to the heads of WZC's on the east coast of Belgium. 302 faeces were received. The data of the residents were not disclosed. The faeces came into the lab the day of collection. If it was not possible, they were stored in the WZC's at 4 ° C in the refrigerator. Once the faeces had arrived in the lab, the samples were stored in the refrigerator. If the tests could not all be performed on the same day, the samples were stored at -20 ° C in the freezer. During the study, each sample was tested with four different standard methods. Namely CerTest the Liaison® XL DiaSorin, mini VIDAS® and culture of bioMérieux. For culture soils Clostridium agar base and ChromID™ agar base were used. All data was recorded in an Excel file, as well as on paper. First, the CerTest was performed. Then the tests followed the Liaison® XL and mini VIDAS®. While waiting for the results of the Liaison® XL and the mini VIDAS®, the cultures were inoculated. When this was done, the faeses were frozen at -20 ° C to await the result of the culture. A sample which gave a negative result by all methodes, was thrown in the hazardous medical waste. The positive samples and with unconformity remained in the freezer.

A positive culture was confirmed with the Microflex™. When it gave any positive toxine result, the colonies were kept alive by seeding and incubating them again in an anaerobic environment. With any positive result a PCR was performed on the GeneXpert®. Any positive results were sent to the reference laboratory of C.difficile at UCL. Five occupants of the 302 persons examined in our study were carrying a toxigenic C.difficile, which corresponds to a prevalent of 1.7 %. No tribe belonged to the virulent Ribo-027 type.

The investigation showed quickly that we were dealing with, if any, weak concentrations. In co-operation with the national reference center UCL we decided to make use of a thioglycolate enrichment agar base.

144 of the 297 negative samples were inoculated and incubated for 10 days. After inoculate the Clostridium plate showed one sample to be extra positive to a toxigenic C.difficile, confirmed by the geneXpert®, Ribo-027 negative.

There can be concluded that the prevalence of carriers of toxigenic C. difficile in the Nursing Homes on the East Coast is 2.3 %.

Samenvatting eindwerk 1 2014-2015: Validation cytological embedding with the Cellient automated cell block system
The aim of this thesis is to determine if the Cellient automated cell block system can be incorporated in the daily routine of the cytopathology of the lab. The Cellient generates a paraffin block from cytology material in one hour, using methanol fixation, compared with traditional cell blocks, which require overnight formalin fixation. Cell blocks can be very useful for diagnostics when used properly. This thesis compares the traditional agar method with the Cellient in terms of cellularity, morphology, staining and immunoreactivity. In addition to the cytological embedding, it can be used for small biopsies and generates faster tissue blocks. This thesis is based on the validation of the Cellient carried out by the University Medical Center in Rotterdam in 2012. They indicate that the Cellient offers many advantages. Other studies who have been consulted are contradictory to each other. Therefore it is important to validate the Cellient in one’s own lab.
The method that is used for the validation is a retrograde study. Different preparations with high cellularity and immunohistochemical staining are used both the agar method as the Cellient. The preparation are evaluated based on different criteria as mentioned above. For the small biopsies the usual formalin fixed paraffin embedding method is compared to the Cellient method.
The result shows that the agar technique has several drawbacks. The Cellient on the other hand shows a superior morphology and several advantages. The most important conclusion of this study is that the processing time is shortened for cytological material without loss of morphological detail and immunoreactivity. For the small biopsies especially mammadiagnostics the Cellient can provide a faster service for samples with malignant origin. 
Samenvatting eindwerk 2 2014-2015: Evaluation of cell count and differentiation on diverse body fluids with the Sysmex XN-1000
Microscopic analysis of body fluids is imprecise and has a wide interobserver variability. Moreover, it is a time-consuming procedure. In a modern medical laboratory setting fast and accurate diagnosis is often required.
We evaluated the performance of the body fluid (BF) module on the Sysmex XN-1000 for counting red and white blood cells and for WBC differential count. 70 BF samples were used for method comparison between the Sysmex XN-1000 and manual microscopy (Fuchs-Rosenthal counting chamber and stained cytospin slides) for counting RBC and WBC and for a WBC differential. Limits of acceptance were obtained from Sysmex and Ricos criteria for peripheral blood. Furthermore within and between run precision was evaluated and both precision test values are accepted. Linearity showed high correlation and carry-over was negligible. The limit of quantification for WBC was defined as 5-6 WBC/µL. Additionally an accuracy and total error evaluation was gained from collected data both were accepted. Results were good and on par with research performed by different institutes. Good agreement was found for counting between the Sysmex XN-1000 and the Fuchs-Rosenthal counting chamber. For WBC and RBC counts a Passing-Bablok regression of respectively Y=1,65 + 1,06X with a Spearman’s rho of 0,956 an Y=132 + 1,02X with a Spearman’s rho of 0,9. When divided into high and low concentration, correlation decreased for the low concentrations (WBC 0,858 and RBC 0,776) while high concentrations continued to have excellent correlation (WBC 0,922 and RBC 0,982). Differentiation was also examined in percentage. Polymorphonuclear cells (PMN) and mononuclear cells (MN) scored respectively Y=0,98+0,98X and Y=0,24+0,99X with Spearman’s rho correlations of 0,865 for both.
We can conclude that the automated body fluid analysis with the XN-1000 is not a substitute for microscopic examination because the identification of malignant cells still requires confirmation by manual microscopy. Cases which carry severe diagnostic consequences should also be reviewed manually. However, it can improve the workflow in a routine laboratory by reducing the numbers of specimens submitted to microscopy by using carefully chosen review criteria.
The BF module is a fast and suitable tool for accurate quantification of WBC (differential) and RBC counts in body fluids in a diagnostic setting.
Samenvatting eindwerk 3 2014-2015: Screening van Carbapenemase Producerende Enterobacteriacea. Een vergelijkende studie tussen ChromID CARBA SMART en Brilliance CRE Agar
The main purpose of this thesis is to evaluate the Brilliance CRE Agar and to compare it with the ChromID® CARBA SMART. The sensitivity and specificity will be examined. Additional tests will be used to confirm the CPE.
It is known that the plates detect bacteria which produce carbapenemase. But how good will the sensitivity be, if the ranges is increased to detect bacteria like Acinetobacter spp. and Pseudomonas spp. beside Enterobacteriacea. Will the increase range effect the specificity? This will be tested on both plates. That’s why there’s a normal method, that concluded only specific colors for CPE from both plates and an adjusted one. The adjusted method for the CRE Agar is to place a temocilline disc on the plate and watch if there’s growth to the disc. The ChromID® is not only looking for the specific colors for CPE but also for colors like brown and yellow.
The samples for the specificity are gathered form the AZ Zeno campus Knokke-Heist and Blankenberge. The samples for the sensitivity are coming from different hospitals. This because of the low amount of positive CPE in the AZ Zeno laboratory.
The specificity is about testing both the CRE and ChromID® for growth on the plate, with a color that suggests a CPE. Further tests must be executed to confirm whether it is a CPE or not.      
To measure the sensitivity, positive CPE will be used on both the CRE Agar and ChromID® plates. This test determined whenever the positive CPE will be detected on the plates or not. There will be two test to conduct the sensitivity, the normal and the adjusted one.
Both the sensitivity and the specificity from the ChromID® CARBA SMART are higher than from the Brilliance CRE Agar with the normal method. When the adjusted method is used, the result for the sensitivity is that the ChromID® is better than the CRE plate. But the result for specificity from the CRE plate is better than from the ChromID®.
Samenvatting eindwerk 2011-2012: MRSA-screening: evalueren van Thermo Scientific Contrast MRSA Broth en Brilliance MRSA 2 Agar
Meticilline resistente Staphylococcus aureus (MRSA) is een bacterie die zowel binnen als buiten ziekenhuizen een steeds groter probleem wordt. Het is een gevreesd pathogeen omdat deze bacterie resistent is tegen vele van de vandaag gebruikte antibiotica. De normale meticilline gevoelige Staphylococcus aureus (MSSA, van het Engels meticillin susceptible Stapylococcus aureus) is persistent aanwezig in ongeveer 20% van de volwassen bevolking terwijl 60% tijdelijk drager is van S. aureus (Staphylococcus aureus). Van deze dragers is een kleine groep gekoloniseerd met een meticilline resistentie vorm. Indien de drager gezond is ondervindt hij of zij er geen problemen van. Als de drager een verminderde lokale of algemene weerstand heeft kan de opportunistische kiem de patiënt infecteren en zorgen voor een zeer moeilijk bestrijdbare infectie, die bovendien fataal kan zijn.
Dit onderzoek focust zich op stalen genomen uit de neus, een frequente kolonisatieplaats van MRSA. De afnames zijn gebeurd gedurende twee maanden uit alle groepen van de populatie, waardoor een beeld wordt bekomen van de incidentie die representatief is voor de totale bevolking in het noorden van West-Vlaanderen. De incidentie kwam neer op 1,53% of 15 op 1000. Twee producten die helpen tijdens de identificatie in het laboratorium zijn getest. Enerzijds een chromogeen aanrijkingsmedium van Oxoid, Contrast™ MRSA broth, dat een kleurverandering heeft bij vermoeden van MRSA. Anderzijds werd een chromogene agarplaat van Oxoid getest, namelijk Brilliance MRSA 2 agar, welke vermoedelijk positieve kolonies een blauwe kleur heeft. Deze twee producten zijn vergeleken met twee andere, namelijk TSB 6,5% NaCl als aanrijking en MRSAselect agar van Bio Rad als chromogene plaat. De aanrijkingen en agarplaten zijn in combinatie met elkaar getest, wat wil zeggen dat na aanrijking (Contrast™ MRSA broth en TSB 6,5% NaCl) geënt werd op beide chromogene platen (Brilliance MRSA 2 en MRSAselect) vanuit de aanrijking. Met de verkregen resultaten zijn de specificiteit, gevoeligheid, positieve predictieve waarde en negatieve predictieve waarde berekend.
Uit de evaluatie van de Contrast™ MRSA broth is gebleken dat dit medium een gevoeligheid van 70,59% heeft in de gebruikte testopstelling. Samen met een lage positieve predictieve waarde heeft dit medium geen betrouwbare kleurverandering bij positieve stalen en worden teveel positieve stalen gemist. De negatieve predictieve waarde en specificiteit liggen daarentegen wel hoog met respectievelijk 99,50% en 95,73%.
Een vergelijkende test van de Brilliance MRSA2 en MRSAselect agarplaten toont dat de gevoeligheid van de beide platen ongeveer gelijk is. Deze gevoeligheid is het grootst bij de agarplaten die geënt zijn met materiaal uit de TSB 6,5% NaCl aanrijkingen waarbij 250µl staal is gebruikt om aan te rijken. De MRSAselect agarplaten scoren telkens het best als er gekeken wordt naar de specificiteit en de positieve predictieve waarde. Met voorgaande vaststellingen kan gesteld worden dat de MRSAselect agarplaten die komen uit de TSB 6,5% NaCl aanrijkingen waar 250µl materiaal gebruikt is om aan te rijken het best scoren in deze testopstelling.


Graaf Jansdijk 162
8300 Knokke-Heist


Traineeship supervisor
Charlotte Trouvé
Bart Lelie
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