[Show abstract][Hide abstract] ABSTRACT: The prevalence of Helicobacter pylori infection is decreasing in developed countries. In this study we included 22,612 patients in whom a first culture of gastric biopsy (routinely performed in our medical centres) yielded an interpretable result over a 20-year period (1988-2007) in Brussels. The effects of patients' age, gender and ethnic background were analysed. The overall proportion of H. pylori-infected patients was 37·7%, with a progressive decline over time (P<10(-5)). A gender effect was observed in adults. The lowest infection rate was observed in Western European patients (n=11,238) with respectively 36·2% and 15·2% infected subjects in 1988 and 2007, compared to 71·7% and 40% in North African patients (n=3200) (P<10(-5)). However, no trend of decline was observed over time in North African children aged ≤9 years. These data show the effects of time, age and ethnicity on the prevalence of H. pylori infection, and its complex heterogeneity in the same cosmopolitan urban area.
Epidemiology and Infection 04/2011; 139(4):572-80. · 2.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We analyzed the rates of antimicrobial resistance of Helicobacter pylori strains isolated from patients from 1990 to 2009 and identified risk factors associated with resistance. Gastric biopsy specimens were collected from several digestive disease centers in Brussels, Belgium. We routinely performed antimicrobial susceptibility testing for clarithromycin (CLR), metronidazole, amoxicillin, tetracycline, and ciprofloxacin. Evaluable susceptibility testing was obtained for 9,430 strains isolated from patients who were not previously treated for Helicobacter pylori infection (1,527 isolates from children and 7,903 from adults) and 1,371 strains from patients who were previously treated (162 isolates from children and 1,209 from adults). No resistance to amoxicillin was observed, and tetracycline resistance was very rare (<0.01%). Primary metronidazole resistance remained stable over the years, with significantly lower rates for isolates from children (23.4%) than for isolates from adults (30.6%). Ciprofloxacin resistance remained rare in children, while it increased significantly over the last years in adults. Primary clarithromycin resistance increased significantly, reaching peaks in 2000 for children (16.9%) and in 2003 for adults (23.7%). A subsequent decrease of resistance rates down to 10% in both groups corresponded to a parallel decrease in macrolide consumption during the same period. Multivariate logistic regression revealed that female gender, age of the patient of 40 to 64 years, ethnic background, the number of previously unsuccessful eradication attempts, and the different time periods studied were independent risk factors of resistance to clarithromycin, metronidazole, and ciprofloxacin. Our study highlights the need to update local epidemiological data. Thus, the empirical CLR-based triple therapy proposed by the Maastricht III consensus report remains currently applicable to our population.
Journal of clinical microbiology 03/2011; 49(6):2200-9. · 4.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study evaluates 3 selective media (Pylori agar [bioMérieux, France], BD Helicobacter agar, modified [Becton Dickinson, USA], and an in-house medium) designed for Helicobacter pylori isolation. Ninety-eight strains were isolated from 400 gastric biopsies. The media were equally efficient for Helicobacter pylori's growth. However, contaminations were only observed using commercial media.
[Show abstract][Hide abstract] ABSTRACT: The effectiveness of Helicobacter pylori eradication regimens is influenced by antibiotic susceptibility of infecting strains. Data concerning antibiotic resistance in children are limited. We report the evolution of primary and secondary resistance in a series of Belgian children during the last 12 years.
From 1989 through 2000, H. pylori gastritis was diagnosed in 569 children, and antibiotic susceptibility tests were performed in 555. Eradication, using different schemes, failed in 128 of 457 treated children. After eradication failure antibiotic susceptibility determination was performed in 87 of 128. Comparison of antibiotic susceptibility of strains isolated from the gastric body and from the antrum was performed in 238 samples.
Resistance to amoxicillin was not observed. The rate of primary resistance to nitroimidazole derivatives was 18.0% (101 of 555) and remained constant throughout this period, whereas primary resistance to macrolides increased from an average of 6.0% (range, 0 to 10%) before 1995 to 16.6% (range, 10 to 25%, P < 0.001) thereafter. Antibiotic consumption in Belgium, especially macrolides, did not show important fluctuations during the study period. Secondary resistance developed in 39 of 87 patients (46%). Strains isolated from different gastric locations show identical susceptibility testing in all but 5 of 238.
Resistance of H. pylori to macrolides increased in our pediatric population which did not appear to correlate with macrolides prescription habits in our country. After eradication failure acquired secondary resistance was observed in one-half of the patients.
[Show abstract][Hide abstract] ABSTRACT: An outbreak of Campylobacter upsaliensis in four Brussels day care centers (A, B-1, B-2, and C) affected 44 children. Diarrhea was the major symptom. From January 1991 to June 1992, the outbreak strain was isolated from 3, 1, and 21 (of 68) children in centers A, B-1, and B-2, respectively, and from 19 of 22 children in center C, IgG, IgM, and IgA antibodies were detected by Western blotting of serum specimens of 9 of 10 and 13 of 16 children in centers B-2 and C, respectively. Strains were typed by biotyping, DNA restriction-based and antibiotic susceptibility typing, whole cell protein and plasmid analysis, restriction fragment length polymorphism (RFLP), and polymerase chain reaction (PCR). On the basis of RFLP and PCR typing, the strains could be divided into two strongly related clonal variants: One was isolated only from the children of center A and the second only from children in the other day care centers.
The Journal of Infectious Diseases 12/1995; 172(5):1298-305. · 5.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: At the age of 5 years, the prevalence of atopic manifestations was analysed in 58 formula-fed "at risk" infants because of a history of atopic disease in at least two first degree relatives. Infants were randomly assigned to receive either a partial whey-hydrolysate formula (n: 28) or a regular cow's milk formula (n: 30) during the first 6 months of life; thereafter, feeding was unrestricted. Only non-breastfed infants were included. The groups did not differ in risk factors or in known confounding factors possibly influencing the incidence of manifestations suggestive of atopic disease. At 6 months, the prevalence of cow's milk protein (CMP) sensitivity was significantly decreased in the hydrolysate group (7% versus 43%; P: 0.002). At the age of 12 (21% versus 53%; P: 0.029), 36 (25% versus 57%; P: 0.018) and 60 months (29% versus 60%; P: 0.016) there was still a significant difference in the number of atopic manifestations, if calculated cumulatively. There was no difference between the groups if only the new cases after the age of 6 months were considered. Eczema was less frequent in the whey-hydrolysate group, but only during the 1st year of life, suggesting a decreased prevalence of CMP sensitivity. During the first 6 months, diarrhoea of non-infectious origin occurred in 8/30 infants (27%) of the adapted formula group, and in no infant in the hydrolysate group. "Colic as single manifestation" was considered of "allergic" origin in 1/28 infants in the hydrolysate group, and in 4/30 infants in the adapted formula group.(ABSTRACT TRUNCATED AT 250 WORDS)
European Journal of Pediatrics 07/1995; 154(6):488-94. · 1.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To validate the technique of HIV-1 culture from whole blood for the quantitation of viral load in infected children.
Forty-three HIV-1-infected children were followed in two paediatric centres.
Quantitative HIV-1 cultures from unfractionated whole blood using an end-point dilution technique were compared with simultaneous quantitative cultures of peripheral blood mononuclear cells (PBMC) and plasma.
Good sensitivity (93%) of the methods used was confirmed. A close correlation (r = 0.80) was observed between HIV-1 titres measured directly from whole blood and those expected from PBMC and plasma titres. The mean whole blood viral load was higher in patients with more severe signs of disease, but the difference did not reach statistical significance. The whole blood viral titres measured sequentially at monthly intervals remained within one dilution of each other in 16 of the 22 patients studied.
In this study, the quantitation of HIV-1 in unfractionated blood allowed for a reliable and sensitive measurement of the whole blood viral load in infected children.
[Show abstract][Hide abstract] ABSTRACT: Bilateral cultures of bronchoalveolar lavage fluid were obtained from eight children with unilateral lobar pneumonia. In four patients bacterial pathogens were not isolated from lavage of the radiologically normal side but were subsequently cultured from the consolidated segment. This pattern helped to exclude contamination by oropharyngeal flora of bronchoalveolar lavage fluid. Bilateral bronchoalveolar lavage may help in the interpretation of lower respiratory tract cultures obtained by fiberoptic bronchoscopy.
Journal of Pediatrics 05/1993; 122(4):606-8. · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Commercially available complement fixation test reagents (Institute Virion Ltd., Rüschlikon, Zurich, Switzerland) available in package format were evaluated for the serodiagnosis of Helicobacter pylori infection. The assay was compared with bacterial culture and histological Giemsa stain of gastric biopsy specimens obtained from 930 patients of different ages and from different ethnic groups, with a variety of upper gastrointestinal tract symptoms. The prevalence, sensitivity, specificity, and positive and negative predictive values, respectively, were 35, 71, 90, 80, and 85% for Belgian patients aged 40 years or younger, 50, 81, 93, 92, and 83% for Belgian patients older than 40 years, and 83, 83, 79, 95, and 48% for Mediterranean patients. Using 645 serum specimens from 226 patients, we also evaluated the complement fixation test for its ability to monitor the eradication of H. pylori following antimicrobial therapy. Overall, H. pylori was eradicated from 122 patients while 104 patients remained infected with the organism. A significant decrease in antibody levels was observed 3 to 6 months after the end of therapy in the group of patients from whom H. pylori was eradicated.
Journal of Clinical Microbiology 01/1993; 30(12):3230-3. · 4.07 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The relationships of 77 aerotolerant Arcobacter strains that were originally identified as Campylobacter cryaerophila (now Arcobacter cryaerophilus [P. Vandamme, E. Falsen, R. Rossau, B. Hoste, P. Segers, R. Tytgat, and J. De Ley, Int. J. Syst. Bacteriol. 41:88-103, 1991]) and 6 reference strains belonging to the taxa Arcobacter nitrofigilis, Arcobacter cryaerophilus, and "Campylobacter butzleri" were studied by using a polyphasic approach, in which we performed DNA-rRNA hybridizations, DNA-DNA hybridizations, a numerical analysis of whole-cell protein patterns after sodium dodecyl sulfate-polyacrylamide gel electrophoresis, an analysis of cellular fatty acid compositions, and a phenotypic analysis and determined DNA base ratios. Our results indicate that "C. butzleri" should be transferred to the genus Arcobacter as Arcobacter butzleri comb. nov., as was suggested by Kiehlbauch and coworkers (J. A. Kiehlbauch, D. J. Brenner, M. A. Nicholson, C. N. Baker, C. M. Patton, A. G. Steigerwalt, and I. K. Wachsmuth, J. Clin. Microbiol. 29:376-385, 1991). A rapid screening of all strains in which we used the sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique revealed five major groups, which were identified by using DNA-DNA hybridization data as A. cryaerophilus (two distinct electrophoretic subgroups), A. butzleri, A. nitrofigilis, and a new species, for which we propose the name Arcobacter skirrowii. The phylogenetic position within rRNA superfamily VI was established for each species. A. butzleri strains and strains belonging to one of the electrophoretic subgroups of A. cryaerophilus had similar fatty acid contents. An analysis of fatty acid compositions allowed clear-cut differentiation of all of the other groups. All of the species could be distinguished by using classical phenotypic tests, although erroneous identifications due to a shortage of clear-cut differentiating tests could occur.
International journal of systematic bacteriology 08/1992; 42(3):344-56. · 2.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The incidence of atopic manifestations was analyzed in infants "at risk" because of histories of atopy in first degree relatives. The incidence of atopic manifestations was significantly reduced (P = .0011) during the first 6 months of life when only the whey hydrolysate was administered (2/32 infants, 6.3%) compared with the incidence when an adapted formula was given (14/35 infants, 40%). This beneficial effect continued during the 6 to 12-month period, after diversification of the diet at 6 months. At the age of 1 year, 7/32 (21.8%) of the infants in the whey hydrolysate group had presented with manifestations of probable atopic disease compared with 17/35 (48.6%) infants in the adapted formula group (P = .021). The incidence of cow milk protein sensitivity was evaluated at 5/32 (15.6%) in the hydrolysate group and 15/35 (42.8%) in the adapted formula group (P = .014). Other foods such as egg and fish may be responsible for manifestations in three infants in hydrolysate group and in five infants of the adapted group (9.4% and 14.3%, respectively NS). These preliminary data show that the administration of a whey hydrolysate during the first 6 months of life to babies "at risk" decreased the incidence of atopic disease up to the age of 12 months. The incidence of cow milk protein sensitivity appeared to be decreased, whereas the incidence of sensitivities to other food proteins was comparable in both groups.
[Show abstract][Hide abstract] ABSTRACT: We evaluated a commercially available second-generation anti-H. pylori immunoglobulin G enzyme immunoassay (EIA) (Cobas Core Anti-Helicobacter pylori EIA; Roche S. A., Basel, Switzerland) for serodiagnosis of H. pylori infection. The results of the assay were assessed in relation to the results of bacterial culture, urease testing, and histological Giemsa stain of gastric biopsy specimens from 1,134 patients with a variety of symptoms relating to the upper gastrointestinal tract. H. pylori was detected in biopsy specimens from 660 (58.2%) patients: 6 had a normal mucosa, 123 had chronic gastritis only, and 531 were found to have chronic active gastritis by histology; endoscopy showed duodenal and gastric ulcers in 137 and 64 patients of the last two groups, respectively. The test was evaluated with different age and ethnic groups. The prevalence, sensitivity, specificity, and positive and negative predictive values were, respectively, (i) for Belgian patients between 18 and 40 years old, 34, 93, 95, 91, and 96%; (ii) for Belgian patients more than 40 years old, 53, 96, 91, 93, and 95%; and (iii) the Mediterranean patients more than 17 years old, 87, 94, 70, 95, and 64%. All sera showing discordant immunoassay results compared with the results of histology and culture of biopsy specimens, as well as those with borderline immunoassay results, were tested further by immunoblotting. Among the EIA results considered false negative, we demonstrated an absence of seroconversion in 14 of 19 patients tested by immunoblotting. Among the EIA results considered false positive, immunoblotting showed the presence of specific antibodies in 28 of 37 patients tested. Among the borderline results obtained in the first assay with 22 patients' sera, a second assay showed positive results in 10 patients (8 were positive by immunoblotting) and negative reactions in 10 patients (9 were negative by immunoblotting), whereas 2 remained borderline. These data indicate that sera showing borderline immunoassay results must be tested again. In conclusion, this commercially available second-generation EIA, which is easy and quick to perform, was found highly reliable for the serodiagnosis of H. pylori infection.
Journal of Clinical Microbiology 02/1992; 30(1):176-80. · 4.07 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: During a 3-year period, "Campylobacter upsaliensis" was isolated from 99 patients. Phenotypic characterization and numerical analysis of protein electrophoregrams showed evidence that "C. upsaliensis" is a distinct Campylobacter species with unique characteristics. The MBCs of 13 antibiotics were determined. In general, these organisms were highly susceptible to drugs that were present in the selective isolation media, making none of the available selective media suitable for the isolation of "C. upsaliensis." Ten strains were found to be resistant to erythromycin (MBCs, greater than or equal to 12.50 mg/liter). Plasmid DNA was detectable in 89 of the 99 strains; 16 plasmid profiles could be identified. Plasmid pattern 16, containing four plasmids of 52, 32, 5.5, and 2.6 megadaltons, represented 60.7% of the plasmid-containing strains. None of the "C. upsaliensis" strains could be agglutinated with antisera against heat-labile antigens from C. jejuni, C. coli, or C. laridis. "C. upsaliensis" was found to be susceptible to serum killing and was readily phagocytized by human polymorphonuclear cells.
Journal of Clinical Microbiology 06/1990; 28(5):1039-46. · 4.07 Impact Factor