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Biomedical subjects

H Leclerc

Publications and source records attributed to H Leclerc.

At least 91 records · Page 5Linked to original sources
PubMed1981

[Taxonomic study of enterobacteria belonging or related to Escherichia coli species].

Phenetic (numerical analysis) and genetic (DNA-DNA hybridization) studies were carried out on strains belonging or related to the species Escherichia coli. They have shown the diversity of its phenotypes, by the presence of plasmidic characters (citrate+, urease+, H2S+, tetrathionate reductase+, raffinose+, and saccharose+). New strains related phenetically to E. coli are also individualized. They showed less than 30% DNA relatedness with E. coli. A new definition of E. coli is presented.

Bacteriological Techniques↗
PubMed1980

Automation of water bacteriological analysis: running test of an experimental prototype.

The experimental apparatus described enables continuous and automatic bacteriological water examination. It ensures the analysis and detection of Escherichia coli by incubation of the water samples and then detection of glutamic acid decarboxylase in coils according to the Technicon principles. The analysis is rapid: it is performed within 13 h with a sensitivity of better than 1 bacterium/100 ml, and 120 samples of 100 ml of water are examined in 24 h. Laboratory experiments and field testing showed that this prototype ensured a specific and sensitive analysis. They also provided information about the frequency of maintenance necessary to retain its efficiency. This device would allow, under the same conditions, the examination of liquid food products.

Autoanalysis↗
PubMed1980

[Quantitative study of the faecal flora in adult and baby artifically fed from birth (author's transl)].

The faecal flora of 33 adults and 14 babies (artificially fed from birth) were determined. The faecal flora were most different. The primary anaerobic flora (prevalent Bacteroïdes and Bifidobacterium) in adults was 99 p. cent from total flora; it was in babies (prevalent Bifidobacterium and Bacteroïdes) 50 at 60 p. cent from total flora. The primary aerobic flora (E. coli and Enterococcus) was 10 to 20 times more numerous in babies than in adults. Therefore the secondary flora was very distinct. By babies we are noting the great diversity of Enterobacteriaceae species, the great frequency (57 p. cent of Pseudomonas aeruginosa (9 p. cent in adult), the important occurrence (21 p. cent) of aeromonas (0 in adults), the constancy of staphylococci (51 p. cent in adults), but the rarity of bacilli, yeast and fungi. The faecal flora of adults was specific and stable.

Actinomycetaceae↗
PubMed1980

[Microcalorimetry in the taxonomy of some groups of Enterobacteriaceae].

The thermogenesis of 17 strains belonging to 12 species of the Enterobacteriaceae family was measured at 30 degrees C with an ampoule microcalorimeter. It was analyzed qualitatively (aspect of profiles) and quantitatively (total heat evolved, thermogenesis duration, maximum thermal power). The value of these criteria is discussed with respect to their discriminating value in the classification of bacteria. The information obtained may concur with the identification of species; it gives ground to reconsider actual phenotypes and genotypes and taxonomy generally.

Calorimetry↗
PubMed1980

Evaluation of Micro-ID, for identification of Enterobacteriaceae.

Micro-ID system is a new identification kit for Enterobacteriaceae which provides the identification at the species level 4 hours after primary isolation. When compared with conventional biochemical tube media, micro-ID gave a 94% agreement. Comparison of Micro-ID with Api 20 E showed a 90% agreement. A comparison of all 3 systems showed that for 90% of the time, the isolates were named the same by the all systems.

Bacteriological Techniques↗
PubMed1980

[Venous return blood in sexual dysfunction in the male (author's transl)].

The author reports a special case where the use of a supple tourniquet, relatively loosely applied and taking both the base of the scrotum and the penis, led to increased erectile turgescence, penile rigidity and duration of erection. Reduction in venous return was considered to be a primary factor in the effectiveness of this technique.

Aged↗
PubMed1980

[Experimental study of bacteriophage removal from the lagoon basin].

Polluted river water was studied in an experimental lagoon to determine efficiency of removal of bacteriophages injected at the inlet of the lagoon. The bacteriophages were not significantly affected by the purification process and were found to migrate to the outlet in 4 to 5 days. They were detected 143 days after injection although about 80% of the added virus was removed by the lagoon treatment. These results contrast with those obtained with Salmonella, 99.9% of which were removed.

Adsorption↗
PubMed1980

[Firefly assay of bacterial ATP: comparative study of extraction methods (author's transl)].

The firefly bioluminescence ATP assay presents multiple applications in microbiological analysis. Nine ATP extraction methods were tested on thirteen Gram positive and Gram negative bacterial species. The DMSO method appears as the procedure for choice. It provides the highest yields and the best reproducibility, even at high bacterial concentrations. It is simple, rapid and can be recommended for routine analysis. Assays carried out after extraction by this procedure show that in 24 hours cultures, the ATP content ranges from 0.28 fg to 15.65 fg per cell depending on species.

Adenosine Triphosphate↗
PubMed1979

[Study of a new group of Enterobacteriacea (group H1) related to Enterobacter cloacae strain].

A DNA-DNA hybridization study was carried out on a new group of enterobacteria (group H1) previously studied by numerical taxonomy work on the genus Enterobacter. This group showed a very high genetic homogeneity since the average relative binding ratio of nine analysed strains is equal to 91%. The taxonomic position of this group into the family of enterobacteria is discussed with the species E. cloacae (37 to 61%), K. pneumoniae (44 to 60%), K. oxytoca (57-58%), L. malonatica (syn. Citrobacter intermedius, a:46 to 54%), L. amalonatica (syn. C. intermedius, b: 51%), and the group H3 (52-61%). The group H1 is defined on phenotypic and genetic data.

DNA, Bacterial↗
PubMed1978

Characterization of motile and acetoin-negative Klebsiella pneumoniae strains by DNA: DNA by hybridization.

Hybridization studies were carried out to determine the extent of divergence between different members of the Enterobacteriaceae and group D, previously described by numerical analysis of phenotypic characters, and comprising strains isolated from surface waters. This group, apparently belonging in or related to the genus Citrobacter on the basis of the IMViC tests differs from this taxon by numerical analysis and DNA base composition. Our work reveals a DNA relatedness of 81-89% between the centrotype strain of this group and the genus Klebsiella. Although strains of group D show positive motility and negative Voges-Proskauer reactions, a comparison of their phenotypic characters leads us to consider that the strains with a high level of hybridization within this group belong to K. pneumoniae. These results suggest a complete revision of the traditional classification scheme of the genus Klebsiella.

Acetoin↗
PubMed1978

[Occurrence of R plasmids belonging to incompatibility group incC in Aeromonas hydrophila strains isolated from sewage water (author's transl)].

The susceptibility to antimicrobial agents of 321 strains of Aeromonas hydrophila was studied: 319 strains were found to be resistant to one or several antibiotics. Transfer of resistance markers was obtained from 24 strains. Five plasmids from these strains were classified into incompatibility group incC. Epidemiological consequences of R plasmid diffusion in water bacteria are discussed.

Aeromonas↗
PubMed1978

[The GC content of a group of H2S- enterobacterial related to the genus Citrobacter].

The deoxyribonculeic acid (DNA) of 106 strains of Enterobacteria was analysed for the guanine + cytosine (GC) content. These strains, whose origin and principal characters are described in the text, belong to the genera Citrobacter (C. freundii H2S-) and Levinea (L. malonatica and L. amalonatica). Four other groups or classes named C.D.E. and F. could not be classified on the base of the usual phenotypic criteria. DNA from the strains of Levinea has a GC% of 50.3 to 53.3, while DNA from the strains of C. freundii H2S- has a GC% of 48.6 to 51.7. The representative values from the new classes are C, 50.9%; D, 54%; E, 52.7%; F, 49.5%. For the latter a genomic heterogeneity was shown, expressing itself as two subpopulations whose average GC% are 51.7 and 48.6 respectively. Statistical analysis of the averages give a significant individuality to these new classes.

Citrobacter↗