[The cardiac pacemaker and melitococcus].
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Aged↗
Biomedical subjects
G Chabanon
Publications and source records attributed to G Chabanon.
Phenotypic and genotypic assays for the detection and identification of adhesins from pyelonephritic Escherichia coli.
Four different gene clusters have been characterized so far which encode adhesins involved in the specific binding of pathogenic Escherichia coli to epithelial cells of the urinary tractus: the pap, sfa, afa and bma operons. The ability to adhere to uroepithelial cells and to interact with one or several of the specific receptors identified for each of the 4 adhesins, has been studied for 102 E. coli strains isolated from patients with pyelonephritis. These receptor-binding assays are referred to as phenotypic assays. Isolates which adhered to uroepithelial cells 68.6% produced at least 1 of the previously described adhesins. In addition, we used DNA probes to detect homologous sequences of the pap, sfa, and afa operons. Genotypic assays revealed that 87.2% of pyelonephretic E. coli contain DNA sequences related to at least 1 of the 4 operons; 78.4%, 22.5% and 11.8% of the strains harboured sequences related to pap, sfa and afa operons, respectively. The afa- and sfa-adhesion determinants were commonly found associated with the presence of the pap operon (8.8% and 18.6%, respectively). Detection of adhesins using the genotypic approach appears to be reliable (all adhesins detected using the phenotypic approach were also detected with probes). Detection by colony hybridization was significantly higher than by phenotypic assay. Discrepancies may have been due to absence of expression of the detected operons and may have resulted from improper in vitro growth conditions, phase variation, and/or heterogeneity of the genes encoding the adhesins within a family of related sequences.
Adhesins, Bacterial↗
[Burkholderia cepacia: dangers of a phytopathogen organism for patients with cystic fibrosis].
Burkholderia cepacia is an environmental bacterium, capable of colonising vegetal and animal tissues, involved in human opportunist nosocomial infections, and above all, in pulmonary colonisations in patients with cystic fibrosis. In these patients, infection may be followed by a severe deterioration with bacteraemia, leading to death. Moreover, owing to the epidemic spread of some clones within cystic fibrosis communities, strict preventive guidelines have to be instituted. Early detection of Burkholderia cepacia colonisation is therefore essential, and requires the use of selective media. Identification by means of conventional procedures may be problematic, all the more as the previously named Burkholderia cepacia strains have been recently shown to constitute five genomovars (I to V), collectively designated the "cepacia complex", of which only three are classified as new species (II = Burkholderia multivorans; IV = Burkholderia stabilis; V = Burkholderia vietnamiensis). Moreover, closely related species, particularly Burkholderia gladioli, are also involved in cystic fibrosis. Many questions still need clarifications, regarding pathogenic mechanisms and propensity for the cystic fibrosis lung of these organisms. Antimicrobial therapeutic options for B. cepacia complex infections are limited by their innate and acquired antibiotic multiresistance.
Burkholderia Infections↗
The Epstein-Barr virus (EBV) in human pathology. II. Serologic profiles of EBV infections.
Antibodies to EBV induced intracellular antigens, (VCA, EA, NA) and VCA-IgM antibodies have been investigated to define EBV serologic profile of 245 individuals. This profile was a first studied in EBV primary infections. In infectious mononucleosis, the efficiency of EBV serodiagnosis is lower than Paul Bunnel Davidsohn reaction (PBD) : primary infection profile is only characterised in 80% of the positive PBD infectious mononucleosis (IM). On the other hand, EBV antibodies are preponderant for diagnosis in other clinical manifestations of EBV primary-infection were PBD is not alwasy positive (47%). EBV antibodies of patients with various diseases and antibodies of normal subjects show different profiles. By interpretation of these profiles one discuss the possibility to characterize reinfection, and either latent or active persistant infection.
Antibodies, Viral↗
In vitro attachment to a human cell line of Escherichia coli strains causing urinary-tract infection: occurrence of fimbriae (pili) in adhesive and non-adhesive strains.
In this study, 20 strains of Escherichia coli isolated from infected urinary-tract were screened for the occurrence of haemagglutinating (HA) activity and for the possible relationship between a fimbriate surface structure and adhesion ability to the surface of a human cell line. Only 8 of the 20 adhesive strains agglutinated human or guinea-pig erythrocytes or both. In 7 of the 8 strains, the haemagglutinating activity with human erythrocytes was D-mannose-resistant; one strain was D-mannose-sensitive with guinea-pig red blood cells (RBC). In 40 non-adhering E. coli isolated from urine, D-mannose-resistant HA was rarely detected; in contrast, agglutination of guinea-pig was more frequent and D-mannose-sensitive when it occurred. No correlation was found between the degree of HA activity and the ability to adhere. Moreover at low growth temperature (18 degrees c), haemagglutinin was absent in all the strains tested, whereas residual adhesion capacity could be detected in some strains. Similar results were recorded after heating the bacterial suspension at 65 degrees C. Generally pili detected by electron microscopy were present at the surface of the strains which agglutinated RBC. There is no correlation between the presence of fimbriae or pili and adhesion of E. coli to the human cell line used in this study. A range of distinct mechanisms of E. coli adhesion appeared to be involved in the phenomenon described in this report.
Agglutination↗
[Cardiopulmonary manifestations of Mycoplasma pneumoniae infections (author's transl)].
Studies to detect the presence of Mycoplasma pneumoniae infection were undertaken in departments of pulmonary medicine, respiratory intensive care, cardiology, between 1973 and 1977. The diagnosis was based upon the complement deviation reaction, with the exclusion or other serological or culture methods. In addition to acute benign pleuropneumonia, 9 cases of severe pulmonary forms were seen: in 4, acute decompensation in the presence of pre-existence chronic insufficiency, and in the other 5 a radiological picture of acute bilateral bronchopneumonia with dyspnoea. Two patients died in a clinical context of progressive coma. Five cardiac forms with a favourable course were diagnosed: one case of acute myocarditis and 4 of acute pericarditis.
Acute Disease↗