Belgian Laboratories Research Articles

Description of Wautersiella falsenii gen. nov., sp. nov., to accommodate clinical isolates phenotypically resembling members of the genera Chryseobacterium and Empedobacter

A total of 26 isolates of non-fermenting, Gram-negative rods, obtained between 1980 and 2004 by various clinical laboratories in Belgium, with phenotypic characteristics resembling those of members of the genera Chryseobacterium and Empedobacter (indole-positive) and a biochemical profile resembling that of CDC group II-h, but urease-positive, were collected at the Université Catholique de Louvain Microbiology Laboratory, Belgium. The 16S rRNA gene sequences were determined for most of the isolates and showed 94-95 % similarity with the type strain of Empedobacter brevis as the closest relative, indicating that these isolates might belong to a separate genus. Furthermore, the 16S rRNA gene sequences of the isolates were similar, but two clusters (genomovars) could be distinguished. The sequence similarities were 99.5-100 % for the 14 isolates of genomovar 1 and 99.4-100 % for the 12 isolates of genomovar 2. The similarity between the two clusters was 98.3-99.5 %. The presence of two clearly different groups was corroborated by using tRNA intergenic length polymorphism analysis, which also enabled differentiation of the novel species from all other species studied thus far using this technique. DNA-DNA hybridization results excluded a close relatedness to Empedobacter brevis. The DNA G+C contents of the reference strains of genomovars 1 and 2 were 33.8+/-0.4 and 34.4+/-0.2 mol%, respectively. The name Wautersiella falsenii gen. nov., sp. nov., is proposed for this group, comprising two closely related genomovars. The type strain of the species and reference strain for genomovar 1 is NF 993(T) (=CCUG 51536(T)=CIP 108861(T)), which was isolated from a surgical wound. The reference strain for genomovar 2 is NF 770 (=CCUG 51537=CIP 108860), which was isolated from blood.

Medians for second-trimester maternal serum markers: geographical differences and variation caused by median multiples-of-median equations

Objectives: To establish gestational age-specific mid-trimester normal medians for the prenatal serum markers α fetoprotein (AFP), human chorionic gonadotropin (HCG) and unconjugated oestriol (uE3) for a Belgian population by using...

A Comparison of Fibre Counting Across Three European National Proficiency Testing Schemes

Proficiency testing (PT) schemes seek to improve and maintain consistency in asbestos fibre counting by circulating mounted samples to laboratories, which return counts for comparison with consensus reference values. This study compares the level of these consensus values in three (Spanish, Belgian and UK) national PT schemes. It also assesses the effect of the imminent change in the European standard rules for counting asbestos fibres, to the new rules from the World Health Organisation (WHO), which will include more fibres. Forty samples from the three schemes were circulated to six laboratories, two in each national scheme. The UK and Spanish laboratories counted using both the ERM and the WHO method. Belgian laboratories already use the WHO method, and they counted only by this method. Densities from counts in this sample exchange served as a common basis against which we compared the national reference values (R). This produced a geometric overall mean ratio of R to exchange mean density of 0.94 for the UK scheme, 1.01 for the Spanish and 0.97 for the Belgian scheme, and thus indicated remarkably similar levels. Nevertheless, non-trivial systematic inter-laboratory differences confirmed the need for regular PT and international inter-laboratory comparisons. Examination of previous data from the national PT schemes and from an international scheme (AFRICA) provided further comparisons for the same laboratories (either comparing the laboratory's data with R values or making direct comparisons between laboratories) that are consistent with those from this special exchange. The change in fibre counting rule (to include fibres apparently touching particles with diameter >3 microm) produced mean increases in reported densities that ranged among samples from 0 to 70% (highest individual estimate 170%); the effect was broadly similar for the three schemes. The laboratories gave mostly similar estimates of percentage increase; however, one laboratory occasionally produced high estimates indicating a possible need for training for using the new method.

ISO 15189: A WORLDWIDE STANDARD FOR MEDICAL LABORATORIES

From the University of Wisconsin Medical School, Department of Pathology and Laboratory Medicine, Madison, WI. Dr. Libeer is head of the department of clinical biology at the National Institute of Public Health in Brussels, Belgium. His department is in charge of licensing medical laboratories in Belgium and is in charge of the organization of the national proficiency testing schemes. Dr. Libeer has a particular interest in laboratory quality management and, along with Dr. Henk Goldschmidt, organizes the Antwerp “Quality in the Spotlight” conferences. In ISO TC212 he represents his national standardization body. He is also president of EQALM (the European umbrella organization of PT providers in clinical laboratories). Reprints: Sharon L. Ehrmeyer, PhD, University of Wisconsin Medical School, Department of Pathology and Laboratory Medicine, Medical Science Center, 1300 University Avenue Madison, WI 53706 (e-mail: [email protected]).

ANTIBIOTIC SUSCEPTIBILITY AND SEROTYPE DISTRIBUTION OF 240 STREPTOCOCCUS PNEUMONIAE CAUSING MENINGITIS IN BELGIUM 1997-2000

Cerebrospinal fluid isolates of Streptococcus pneumoniae, collected during the years 1997-2000 at more than 100 Belgian laboratories were studied. The 10 most common serotypes-serogroups representing 76 % of the isolates were 14, 6, 9, 19, 23, 18, 4, 10, 8 and 12 (in order of frequency). Thirty-six percent of strains were isolated in children < 5 years old. In this age group the number of serogroups was more limited and 81.4 % are included in the 7-valent conjugate vaccine. Decreased susceptibility to penicillin was observed in 13.9 % of 237 strains (MIC > 0.06 mg/L), with only 2.1 % resistant strains (MIC > 1 mg/L). Twelve strains showed reduced susceptibility to cefotaxime (MIC > 0.5 mg/L). Only three of the 237 strains were intermediately susceptible to meropenem. All strains were susceptible to vancomycin and moxifloxacin.In Belgium, high doses of third generation cephalosporins remain effective for the treatment of pneumococcal meningitis. The new fluoroquinolones seem the most promising agents for the treatment of pneumococcal meningitis in the future.

Analysis on residues of estrogens, gestagens and androgens in kidney fat and meat with gas chromatography–tandem mass spectrometry

The use of estrogens, gestagens and androgens (EGAs) in animal fattening is prohibited in the European Community. Based on the general detection capabilities of Belgian laboratories, National Minimum Required Performance Limits (National MRPLs) for a number of EGAs have been imposed by the inspection services. Selective hyphenated techniques, e.g. GC–MS and GC–MS 2, with high detection capability are needed. β-Trenbolone, which is meant to be a “problem” molecule for GC–MS, can be detected at the 2 μg/kg level using GC–MS 2. Based on the National MRPLs in different matrices, our laboratory has divided the EGAs into a class system. In this set-up, analysis of EGAs in kidney fat and meat is discussed.

Automated 5′ nuclease assay for detection of virulence factors in porcine Escherichia coli

This paper describes the development of a 5′ nuclease assay for detection of virulence factor genes responsible for colonization factors and toxins in Escherichia coli isolated from pigs. Colonization factors were F4, F5, F6, F18, F41 and the outer membrane protein intimin. Toxins were heat stable (STa, STb, EAST1) and heat labile (LT) enterotoxins and the verocytotoxin variant 2e (VT2e). To correctly identify false negative results, an endogenous internal control targeting the E. coli 16 S rRNA gene was incorporated in each test tube. The assay was evaluated using a collection ofE. coli reference strains which have previously been examined with phenotypical assays or DNA hybridization. Furthermore, the assay was evaluated by testing porcine E. coli field strains, previously characterized. The 5′ nuclease assay correctly detected the presence of virulence genes in all reference strains. When testing field strains there was generally excellent agreement with results obtained by laboratories in Belgium and Germany. In conclusion, the 5′ nuclease assay developed is a fast and specific tool for detection of E. coli virulence genes in the veterinary diagnostic laboratory.

Evolution of Streptococcus pneumoniae serotypes and antibiotic resistance in Belgium—update (1994–98)

To follow the evolution of capsular types and resistance of Streptococcus pneumoniae, isolated from deep sites. More than 100 Belgian laboratories permanently collect S. pneumoniae strains isolated from puncture specimens (blood, cerebrospinal fluid, middle ear fluid, etc.) and forward them to the reference center in Leuven, in order to determine the capsular serogroups and types (SGTs) and their resistance. From 1994 to 1998, the 5486 S. pneumoniae strains examined belonged to 39 of the 46 currently identified SGTs. The 10 most frequent SGTs accounted for 78.9% of the isolates, and 97% of all isolates belonged to SGTs included in the 23-valent vaccine. Overall mortality of patients with pneumococcal bacteremia or meningitis was 9.7%, and 23.8% in patients over 80 years. From 1994 to 1998, resistance to penicillin (P) increased from 7.6% to 14.2%, to tetracycline (T) from 14.9% to 28.0%, and to erythromycin (E) from 22.9% to 31%. Triple resistance (PTE) increased from 0.9% in 1994 to 6.6% in 1998. Five SGTs (6, 9, 14, 19 and 23) accounted for 50% of the isolates, but for > 90% of the penicillin-resistant or erythromycin-resistant isolates. Resistance of S. pneumoniae to penicillin, erythromycin and tetracycline is steadily increasing and is concentrated in five serotypes included in the 23-valent pneumococcal vaccine. Increasing resistance and high mortality of invasive infections are an incentive to vaccinate vulnerable groups.

Blinded, multicenter quality control study for the quantification of human immunodeficiency virus type 1 RNA in plasma by the Belgian AIDS reference laboratories

In order to evaluate the interlaboratory variation of HIV-1 RNA measurements in plasma, the Belgian AIDS reference laboratories organized a blinded multicenter quality control study. Atest panel of coded spiked HIV-1 plasma samples reflecting the dynamic range of the assay was composed and distributed. The HIV-1 RNA concentration of these samples was determined by the eight Belgian AIDS reference laboratories by means of the Amplicor HIV-1 Monitor version 1.5 assay. Analysis of the results demonstrated that there was little interlaboratory variation for the high concentration range (4.0-5.7 log10 copies/mL), never exceeding 0.2 log10 copies/mL. However the standard deviation for the low concentration range (2.6-3.9 log10 copies/mL) reached up to 0.22 log10 copies/mL. Since interlaboratory variability never reached 0.5 log10 copies/mL and each of the laboratories was able to detect four-fold differences in plasma HIV-1 RNA levels, the Amplicor assay can be used in multicenter studies without a centralized analysis of samples. Furthermore, this well-characterized proficiency panel of spiked plasma samples could be used as a standard in the study of interassay comparisons.

Multicenter study of reference stabilized human blood for lymphocyte immunophenotyping quality control in flow cytometry

The development of automated methods and normative rules, as well as the dependence of some therapeutic approaches on lymphocyte subsets counts, has led to the appearance of calibration reagents. Such reagents are expected to perform equally well in very different settings. We developed a multicenter trial to evaluate the performance of a new quality control reagent, i.e., stabilized blood to be used in immunophenotyping laboratories. Aliquots of the same batch of stabilized blood were shipped to 45 French and Belgian laboratories on a Monday and had to be tested for percentages and absolute counts of at least CD3-, CD4-, and CD8-positive lymphocytes on 4 consecutive days. The percentages and absolute counts obtained on each assay were recorded, as well as the type of lysis used, the trademark of reagents, and the brand of flow cytometer. The mean values collected did not differ significantly from those expected by the manufacturer. Absolute counts generated through one-step techniques displayed lower CVs. This new reagent therefore appears to be a robust product, liable to yield consistent results in the array of different conditions represented by routine laboratories, and it could be useful for quality control procedures.

Multicenter study of reference stabilized human blood for lymphocyte immunophenotyping quality control in flow cytometry

The development of automated methods and normative rules, as well as the dependence of some therapeutic approaches on lymphocyte subsets counts, has led to the appearance of calibration reagents. Such reagents are expected to perform equally well in very different settings. We developed a multicenter trial to evaluate the performance of a new quality control reagent, i.e., stabilized blood to be used in immunophenotyping laboratories. Aliquots of the same batch of stabilized blood were shipped to 45 French and Belgian laboratories on a Monday and had to be tested for percentages and absolute counts of at least CD3-, CD4-, and CD8-positive lymphocytes on 4 consecutive days. The percentages and absolute counts obtained on each assay were recorded, as well as the type of lysis used, the trademark of reagents, and the brand of flow cytometer. The mean values collected did not differ significantly from those expected by the manufacturer. Absolute counts generated through one-step techniques displayed lower CVs. This new reagent therefore appears to be a robust product, liable to yield consistent results in the array of different conditions represented by routine laboratories, and it could be useful for quality control procedures. Cytometry (Comm. Clin. Cytometry) 38:127–132, 1999. © 1999 Wiley-Liss, Inc.

Surveillance of human Yersinia enterocolitica infections in Belgium: 1967-1996.

Between 1967 and 1996, > 18,700 strains of Yersinia species, excluding Yersinia pestis, were recovered in Belgium from a variety of gastrointestinal and extraintestinal sites in patients. Full identification and serotyping were performed by the two Belgian reference laboratories. Yersinia enterocolitica serogroup O:3 predominated (79.4% of strains), followed by serogroup O:9 (11.1%). The remaining 9.5% of isolates belonged to serogroups and related species generally considered nonpathogenic. Acute enterocolitis was the most common clinical form of Y. enterocolitica infection, affecting primarily children younger than 5 years of age. Since 1967, there was a steady increase in isolations every year, with 305 cases in 1975 and up to 1,469 in 1986. From 1987 on, there was a clear decrease in the number of reported cases, although the number of participating laboratories and culture techniques remained constant. This significant decrease in the occurrence of Y. enterocolitica infections may be explained by changes in the slaughtering procedures and eating habits of the population.

External quality assessment (EQA) of Belgian clinical laboratories. The telematics paradigm

Technology that enables communication between information systems has recently become cheaper and more powerful. It is therefore timely to consider the effects of the introduction of such techniques in external quality assessment (EQA) schemes on both users and organizers. Traditionally, results are returned to EQA organizers as hand-written numbers on structured forms. These data are then manually entered into a computer. The process is time-consuming, slow (as it depends on the postal service), prone to error at every transcription stage, and expensive, as clerical staff must be employed to input the data. Computer-to-computer communication allows this process to be improved. A telematics system for electronic data interchange has been developed for the Belgian EQA programme and it offers several advantages, such as the use of standardized semantics, expression of results in laboratory familiar units, possible interface with the Laboratory Information System, faster data analysis, shorter report time and long-term performance evaluation.

Which Bacteria are Found in Belgian Women with Uncomplicated Urinary Tract Infections in Primary Health Care, and What is Their Susceptibility Pattern Anno 95-96?

SummaryDysuria is a frequent reason for encounter in general practice and also gynaecologists and urologists will be frequently confronted with it. In female patients 1/2 to 2/3 of dysuric episodes are due to urinary tract infections. In nearly all cases therapy is started before the result of a culture is available. Therefore it is very important to know which bacteria are most prevalent in the treated population, and what their susceptibility pattern is. Because most available information is based on retrospective data issued from very mixed populations, we performed a prospective study including the most frequently involved population: symptomatic adult women without any symptom of complicated UTI.Among 279 urine specimens collected in general practices, 164 were positive (59 %). The most frequent microorganism found was E.coli (78%), followed by S.saprophyticus (9%) and Proteus spp. (4%). In the 15 remaining specimens, 8 different bacterial species were found. Overall resistance to ampicillin was 30%, to cotrimoxazole 14%, to nitrofurantoin 7%, to fluoroquinolones 1%. The E.coli resistance to ampicillin was 27%, to co-trimoxazole 17%, to nitrofurantoin 1% and to fluoroquinolones 1%.In this population the same bacteria, in the same proportion, are found as in earlier studies in other countries. The susceptibility pattern confirms a substantial resistance level to ampicillin and co-trimoxazole. On the contrary, resistance to nitrofurantoin and fluoroquinolones is negligible. Resistance data from Belgian regional laboratories in their outpatient population were significantly different from ours.

The Contribution of National Laboratories to the European Scientific Labour Market

This article deals with the ways in which differing government policies in relation to national laboratories affect training, employment and culture within the research establishment and consequently the preparedness of respective countries to deal with future skills needs in private and public sector science. Helen Lawton Smith bases her discussion around a study which tested the hypothesis that political decisions in the UK over the past few years regarding the role of national laboratories have inhibited the country's capacity to meet the labour resource needs of the science base. The study included an empirical investigation of nine national laboratories in Belgium, France and the UK. In light of the findings from this comparative analysis, she suggests that moves towards the commercialization of UK national laboratories have had a number of adverse effects on the potential supply of skills to both public and private sectors.

Capsular types and antibiotic susceptibility of pneumococci isolated from patients in Belgium with serious infections, 1980-1993.

During the 13-year period from 1 November 1980 to 31 January 1993, we received and serotyped a total of 5,619 clinically significant strains of Streptococcus pneumoniae isolated in more than 75 laboratories in Belgium (4,079 [72.6%] were from blood or pleural fluid, 462 [8.2%] were from cerebrospinal fluid, 691 [12.3%] were from middle ear aspirates, and 387 [6.8%] were from various other body fluids). The isolates belonged to 64 of the 84 currently recognized serotypes. Among the 4,722 isolates tested for susceptibility since 1983, 22% were resistant to at least one antimicrobial agent. Resistance to penicillin has slowly increased since 1985 but remained stable at a level of 2%-4% between 1986 and 1993. Of the 119 isolates with reduced penicillin susceptibility, only 23 were fully resistant (MIC, > or = 2 micrograms/mL) and none of these proved to be resistant to cephalosporins. Resistance to erythromycin increased significantly from 5.2% in 1986 to 21.5% in 1993. Resistance to penicillin and erythromycin was also more frequently recognized in a smaller number of capsular types of S. pneumoniae.

Report on a common survey in clinical laboratories in Belgium and in the Netherlands: Immunoassays

Report on a common survey in clinical laboratories in Belgium and in the Netherlands: Immunoassays

Report on a common survey in clinical laboratories in Belgium and in the Netherlands: Immunoassays

A common survey for immunoassays was organized for Belgian and Dutch laboratories. We compared the different statistical approaches used in the two schemes; both approaches lead to comparable results. Differences in overall consensus values and overall precision are related to a different selection of kits in the two countries. When analyzing results from users of representative kits in both countries, we found a very good correlation in accuracy but detected also some significant differences in precision for some samples for cortisol and theophylline determinations. For some observed differences there is actually no acceptable explanation.

Capsular types and antibiotic sensitivity of pneumococci isolated from patients with serious infections in Belgium 1980 to 1988

A total of 2,765 strains of Streptococcus pneumoniae isolated in more than 60 Belgian laboratories from blood or normally sterile body fluids between 1 November 1980 and 31 December 1988 were serotyped. From January 1983 onwards susceptibility of the strains to antimicrobial agents was also tested. The 2,765 isolates belonged to 57 of the 84 currently identified serotypes. Overall, 94% of the strains were represented in the current 23-valent vaccine. The remaining 6% of strains were distributed among 18 serotypes. More than 84% of the middle ear fluid isolates came from children under ten years. Meningitis was commonest in children under five years and in adults over sixty years. Two-thirds of pneumococcal bacteremia isolates came from patients over 50 years. Of 1,933 isolates tested for susceptibility to antibiotics, 335 (17%) were resistant to one or more of the agents tested (tetracycline, erythromycin, chloramphenicol, penicillin). Only 19 strains were relatively resistant to penicillin, while six were fully resistant. Resistance to erythromycin increased significantly from 5.2% in 1986 to 11.5% in 1988. The resistance of Streptococcus pneumoniae to other antimicrobial agents did not change significantly during the study period. There was no relationship between age group and resistance to any of the agents tested.

Sound transmission loss of glass and windows in laboratories with different room design

Systematic research has been carried out in two Belgian laboratories on the sound transmission loss (STL) of glass panels and windows to investigate the influence of room design. The samples used were three glass panels with the same dimensions, but different thicknesses. Research has also been done on glass panels of the same thickness inserted into three different frames of PVC, aluminium and wood, which are normally used in practice. The different glass panels and windows were fixed in a niche between the transmitting and receiving room with the same edge dimensions. Systematic STL measurements have been done with the conventional two-room method in both laboratories and the sound intensity method has been used at the AHCL. The windows are of the type which can be opened and the airtightness, to get an optimum STL, has been controlled and improved if necessary. The design of the niche opening in the two laboratories is different and this results in some systematic discrepancies in the STL. Also the influence of loudspeaker and microphone positions has been investigated.