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Biomedical subjects

M Delmée

Publications and source records attributed to M Delmée.

At least 55 records · Page 3Linked to original sources
PubMed1993

Heterogeneity of Clostridium difficile isolates from infants.

In order to improve our understanding of the role of Clostridium difficile in infants we characterised the strains isolated from this population. The production of toxin A and toxin B was studied. The toxin A, playing a major role in the disease, was searched for in faecal samples. The serogroup of the isolates was determined because some serogroups have been shown to be more pathogenic than others. Over a 9-month period, 102 faecal samples from 102 hospitalised infants (0-12 months) were analysed and 26% of the children were colonised with C. difficile. Fifteen isolates secreted neither toxin A nor B (62.5%). Nine isolates were toxigenic and secreted both toxins (37.5%). Of the eight toxigenic strains tested, six were from serogroup H and two serogroup K. Of the 13 nontoxigenic strains tested, 8 belonged to serogroup D, 2 to serogroup X, and 1 each to serogroup A, serogroup B and serogroup C. Three infants out of 102 studied had toxin A in their faeces. In summary, the infants can be colonised by (1) nontoxigenic strains, most of them from nonpathogenic serogroup D, without toxin A in the faeces; (2) toxigenic strains of virulent serogroups H and K, with or without toxin A in the faeces. Although some infants had diarrhoea, none needed a specific treatment for C. difficile. No specific C. difficile pathology could be retained and different mechanisms are advanced to explain this absence of pathogenicity.

Bacterial Toxins↗
PubMed1993

Comparison of enterotoxin production, cytotoxin production, serogrouping, and antimicrobial susceptibilities of Clostridium difficile strains isolated from AIDS and human immunodeficiency virus-negative patients.

We analyzed and compared Clostridium difficile strains isolated from diarrheic stools of 49 human immunodeficiency virus (HIV)-negative and 50 AIDS patients. Our results suggest that distribution patterns of serogroups are different in these two populations. Serogroup C (which has been previously reported to be very resistant to antimicrobial agents) represents 66.0 and 18.4% of the isolates from AIDS and HIV-negative patients, respectively (P < 0.001); the selection of serogroup C could be explained by multiple antibiotic pressure to which AIDS patients have been subjected.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Use of an enzyme-linked immunoassay for Clostridium difficile serogrouping.

An enzyme-linked immunoassay (ELISA) with 11 Clostridium difficile serogroup-specific antisera was applied for serogrouping of C. difficile colonies from 314 consecutive positive fecal samples. Two hundred forty-nine strains (79%) were correctly serogrouped, 57 (18%) belonged to serogroups other than the 11 which were evaluated and gave a negative reaction with all antisera, and 8 isolates (2.5%) did not react with their corresponding antisera. ELISA is a rapid and reliable method for serogrouping C. difficile and should allow for the automation of this procedure.

Animals↗
PubMed1993

Detection of Clostridium difficile toxins in stools. Comparison between a new enzyme immunoassay for toxin A and other routine tests.

An enzyme-linked immunosorbent assay (ELISA) for detection of Clostridium difficile toxin A (enterotoxin) using a monoclonal antibody is described. No cross-reaction was observed with any of the Clostridium species tested except for toxigenic Clostridium difficile. One hundred and eight stool specimens from hospitalized patients harbouring C. difficile in their intestine and 43 samples negative for C. difficile isolation were studied to compare this test with a cytotoxicity assay, the isolation of toxigenic C. difficile and the commercial EIA Premier test (Meridian). As compared with the cytotoxicity assay and EIA, specificity was 91 and 100%, while sensitivity 83 and 74% respectively. This ELISA technique could be used as a routine test for toxin A detection in stools.

Adolescent↗
PubMed1992

Evaluation of a new commercial Clostridium difficile toxin A enzyme immunoassay using diarrhoeal stools.

A new, commercially available enzyme immunoassay for the detection of toxin A in stool specimens, the Premier Clostridium difficile Toxin A test (Meridian Diagnostics), was evaluated using 228 diarrhoeal stool specimens. Using a cytotoxin assay on HeLa cells as the reference method, this new test resulted in a sensitivity of 88% and a specificity of 95%. Using the presence or absence of a toxigenic strain in the stools as the reference method, the sensitivity was similar to that of the cytotoxin assay (71.7+ versus 70.5%) and the overall correlation was even better (89.4% versus 82%). The Premier Clostridium difficile Toxin A assay is rapid and easy to perform and is an excellent alternative to the usual toxin B assay.

Bacterial Toxins↗
PubMed1991

Clinical and serological studies in a series of 45 patients with Guillain-Barré syndrome.

We retrospectively reviewed the clinical files of 45 Guillain-Barré syndrome (GBS) patients admitted to our Department between 1979 and 1989. The age distribution was bimodal with a first peak in young adults (20-40 years), and a second one between 60 to 70 years. Seasonal distribution showed a late fall and a hivernal predominance. Three patients experienced a second attack of GBS 2-9 years after the first one. Thirty-one (69%) presented antecedent events, most often a respiratory tract infection (n = 20) or enteritis (n = 6). Serological studies were systematically performed, including antibody titers against herpes simplex virus, Epstein-Barr virus, cytomegalovirus (CMV), respiratory syncytial virus, human immunodeficiency virus, Mycoplasma pneumoniae, Campylobacter jejuni/coli and cardiolipin. These studies showed the presence of antibodies indicative of a CMV primary infection in 22% cases and of a Campylobacter jejuni/coli infection in 13%. Co-infection was observed in 3 cases. Serology remained negative in 12 patients with a preceding respiratory infection. There was no correlation between serology and the severity of the disease. Absence of antecedent events and of positive anti-infectious serology was observed in only 10 patients.

Adult↗
PubMed1991

[Clostridium difficile: a typing method for epidemiological studies].

One hundred and twenty two strains of Clostridium difficile were studied: 33 strains were isolated from stools of neonates or children, 89 cases of antibiotic associated diarrhea. The strains were identified by biochemical tests and gaz liquid chromatography of the fermentation products. A typing scheme for Clostridium difficile were proposed by using a polyacrylamide gel electrophoresis of whole cell proteins. We studied the correlation between this typing and the serogrouping scheme based on slide agglutination with a rabbit antisera and previously described by Delmée. The serogrouping defines 10 groups, PAGE allows the differentiation of 12 profiles, with a good correlation between the two methods for some serogroups except for the heterogenous serogroup A.

Bacterial Proteins↗
PubMed1990

Primary infection of ascitic fluid with Clostridium difficile.

A case of a primary infection of ascitic fluid with a toxigenic strain of Clostridium difficile is described. The strain belonged to the serogroup H which is often implicated in pseudomembranous colitis. Nevertheless, our patient did not have any sign of colitis or diarrhoea before the ascitic infection. She was successfully treated by the intravenous administration of metronidazole but relapsed a few weeks later. A similar strain of serogroup H was again isolated.

Ascites↗
PubMed1990

Detection of specific antigens for ten serogroups of Clostridium difficile.

We previously described a serogrouping technique for Clostridium difficile based on slide agglutination with rabbit antisera raised against formol-treated cells. It allows the differentiation of ten serogroups, namely A, B, C, D, F, G, H, I, K and X. Each serogroup displays a specific profile with several distinctive bands by polyacrylamide gel electrophoresis (PAGE). In this study we investigated the common and specific antigenic determinants of the ten serogroups by immunoblotting. In a first experiment, whole cell proteins of the ten reference strains were separated by SDS-PAGE, transferred onto nitrocellulose membrane and immunoblotted against their homologous and heterologous antisera. Each serogroup was characterized by several common bands and one or two specific antigens which were proven to correspond to the lowest molecular weight distinctive band observed on PAGE profiles. New rabbit antisera were subsequently raised against the purified specific antigen obtained by electro-elution from polyacrylamide gels. Immunoblots were repeated with these new antisera: all reactions were serogroup specific except one minor cross reaction between C and F. The antisera still agglutinated the homologous strain without any cross agglutination, suggesting that the serogroup specific determinant is a surface antigen responsible for agglutination.

Animals↗
PubMed1990

Comparison of anti-Helicobacter (Campylobacter) pylori IgG antibodies between different areas of Belgium.

We have collected sera from 4053 patients of different parts of Belgium. Sera were randomly selected whatever the kind of pathology. Anti-Helicobacter (Campylobacter) pylori IgG were determined with an ELISA technique using whole formalized bacteria. The results suggest that the mean antibody titres differ between various areas, with an overall higher prevalence in the north-western part of the country.

Adult↗
PubMed1990

Virulence of ten serogroups of Clostridium difficile in hamsters.

A slide agglutination technique identifying 10 serogroups of Clostridium difficile (A,B,C,D,F,G,H,I,K and X) has been described previously. In this study, we have used the hamster to compare the ability of the 10 serogroup reference strains to colonise and produce disease. Groups of four hamsters were each given a single intraperitoneal injection of either clindamycin or cefoxitin, and an oral challenge dose of C. difficile. The time taken to establish faecal colonisation and the length of survival after colonisation were monitored. All hamsters treated with cefoxitin became colonised by day 3 and those challenged with the cytotoxigenic strains of serogroups A,C,H and K developed colitis and died. Among those challenged with the non-toxigenic strains of groups B,D,I and X and the toxigenic strains of groups F and G, faecal colonisation was established without signs of disease. This demonstrates that there are differences in virulence even among toxigenic strains of C. difficile. The same phenomenon was observed after treatment with clindamycin but the pattern of colonisation was quite different with some strains. In the hamsters challenged with toxigenic strains of groups C and K and non-toxigenic strains of groups D and I, which are highly resistant to clindamycin, the response was the same as with cefoxitin. The results were different with strains which were susceptible to clindamycin. Some animals became colonised much later than those treated with cefoxitin but the mortality was similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Characterization of flagella of Clostridium difficile and their role in serogrouping reactions.

Slide agglutination with rabbit antisera allows the differentiation of 10 serogroups of Clostridium difficile, namely, A, B, C, D, F, G, H, I, K, and X. Each serogroup displays a specific protein profile in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, except for A, which displays 12 different protein profiles (A1 to A12). In the present work, electron microscopy revealed the presence of uniformly distributed flagella in the reference strains of serogroups G and K and in all strains representative of the 12 subgroups within serogroup purified by differential centrifugation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of these preparations revealed one distinct band with an apparent molecular mass of approximately 39 kilodaltons. Antiserum was prepared by immunizing a rabbit with the serogroup A flagellin, which had been eluted from the gel. In immunoblotting, this antiserum cross-reacted with the flagellin of the other strains. When the cells were deflagellated by a short sonication, the cross-reactions observed by slide agglutination with A, G, and K antisera were suppressed. Similarly, shearing of flagella allowed specific slide agglutination of the 12 subgroups of serogroup A.

Agglutination Tests↗
PubMed1989

Legionella spp. in a hospital hot water system: effect of control measures.

Potential sources of Legionella spp. in a university hospital were investigated over 3 years in order to gain better understanding of the ecology and transmission of this organism to hospitalized patients. The survey highlighted the contamination of the hot water system with high concentrations of legionellas (up to 10(6) cfu 1(-1]. Legionella pneumophila serogroup 6 was predominant followed by L. pneumophila serogroup 10. Serogroup 1 and other species (L. longbeachae, L. micdadei) were rarely isolated. Serogroup 6 was also the predominant cause of nosocomial legionellosis in 15 sporadic cases in immunocompromised patients from 1981 to 1987. In light of this problem, several control measures were tried consecutively. A disinfection cycle with 6 ppm free chlorine failed to eradicate legionellas because of difficulties with the plumbing system. Raising the temperature in hot water tanks to 80 degrees C was effective locally, but mixer tanks where cold and hot water (60-65 degrees C) are mingled in order to achieve 45 degrees C became the principal reservoirs. Disconnecting the mixer tanks, maintaining a temperature of 60 degrees C in the heating tanks and accelerating the flow rate in the hot water system proved to be the most useful measures.

Belgium↗
PubMed1988

Clostridium difficile in neonates: serogrouping and epidemiology.

A typing scheme for Clostridium difficile based on serogrouping, toxigenicity and sorbitol fermentation was applied to 270 strains isolated in one neonatal ward during a 6-month prospective study. Two hundred and twenty-three strains were isolated from 377 faecal samples of 114 neonates and 47 from 92 environmental specimens. The isolates were distributed among five different types; 87% of the faecal and 85% of the environmental isolates belonged to two of these types (toxigenic, sorbitol negative, serogroup F and nontoxigenic, sorbitol positive, serogroup A). Nosocomial spread was clearly demonstrated and the environment appeared to be the main source of contamination: most of the neonates were colonized after admission by strains found in their environment; clusters of colonization with unusual isolates were observed following referral of patients from the intensive care unit or from other hospitals. No relation was found between the acquisition or the carriage of C. difficile and any intestinal symptoms. All the strains belonged to types different from those usually found in cases of antibiotic associated colitis (AAC) suggesting differences of pathogenicity among the different types.

Clostridium↗
PubMed1988

Incidence and significance of Clostridium difficile in hospitalized cancer patients.

The aim of the study was to assess the incidence and clinical significance of Clostridium difficile in patients in our cancer center. Over a period of seven consecutive months, 557 stools samples obtained from 156 hospitalized cancer patients (37 leukemic patients receiving oral antimicrobial prophylaxis and 119 patients from whom a stool sample was sent to the laboratory) were analyzed for the presence of Clostridium difficile. Clostridium difficile and/or its toxin was recovered from 13 (35%) of the 37 patients receiving oral antimicrobial prophylaxis, and from 15 (12%) of the other 119 patients (p less than 0.05). Isolation of Clostridium difficile was associated with diarrhoea in 13 (46%) of 28 patients but specific treatment was initiated only in 7 (25%) of the 28 patients in whom Clostridium difficile was isolated. The wide distribution of the serotypes identified in our patients does not suggest an epidemic situation in our hospital.

Carrier State↗
PubMed1988

Correlation between serogroup and susceptibility to chloramphenicol, clindamycin, erythromycin, rifampicin and tetracycline among 308 isolates of Clostridium difficile.

The susceptibility to chloramphenicol, clindamycin, erythromycin, rifampicin and tetracycline of 308 isolates of Clostridium difficile from various origins was determined by a disc diffusion susceptibility testing and the results were compared with the serogroup of the strains. For the five antimicrobials, there was a clear-cut separation between susceptible and resistant strains. Some correlation between resistance and serogroup was found. Almost all of the 161 isolates of serogroups A, F, G, H and X were susceptible to all antibiotics. The 32 toxigenic isolates of serogroup C were characterized by a typical resistance pattern which could be used for typing purposes. Other serogroups showed variable patterns. The review of 64 cases of antibiotic associated diarrhoea showed that these differences in susceptibility could have clinical implications: all seven cases due to clindamycin were caused by a clindamycin resistant strain of serogroup C, whereas cases associated with other antibiotics were distributed among various serogroups.

Anti-Bacterial Agents↗