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H Leclerc

Publications and source records attributed to H Leclerc.

At least 19 recordsLinked to original sources
PubMed1992

Rapid detection of members of the family Enterobacteriaceae by a monoclonal antibody.

Six monoclonal antibodies directed against enterobacteria were produced and characterized. The specificity of one of these antibodies (CX9/15; immunoglobulin G2a) was studied by indirect immunofluorescence against 259 enterobacterial strains and 125 other gram-negative bacteria. All of the enterobacteria were specifically recognized, the only exception being Erwinia chrysanthemi (one strain tested). Bacteria not belonging to members of the family Enterobacteriaceae were not detected, except for Plesiomonas shigelloides (two strains tested), Aeromonas hydrophila (five strains tested), and Aeromonas sobria (one strain tested). This recognition spectrum strongly suggested that CX9/15 recognized the enterobacterial common antigen. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot (immunoblot) experiments, the six antienterobacteria antibodies presented similar specificities; they all revealed only one band with an apparent molecular weight of about 20,000 from the crude extract of an enterobacterium. The six monoclonal antibodies, and especially CX9/15, can be used to develop new tests for rapid and specific detection of enterobacteria.

Antibodies, Monoclonal↗
PubMed1992

[Bacterial flora of two sources of natural mineral waters; characterization by restriction patterns of the genes coding for ribosomal RNA; specificity and biological stability].

The bacterial flora of natural mineral waters was analysed using ribosomal ribonucleic acid gene restriction patterns in addition to customary identification techniques. Two springs were studied between 1989 and 1990 and six water samples per source were examined. Among the 206 bacterial strains collected at the spring, 91 (49%) were identified at species level using the API system and 99 representative strains from the two sampling points were selected for ribosomal ribonucleic acid gene restriction analysis. Forty six patterns were detected without common patterns to two springs. The bacterial association of each mineral water has a specific character (100% of specific patterns) shown by a series of patterns, not common to the other spring. This bacteriological specificity is preserved over a marked period of time, as, for each source, a great number of characteristics patterns was repeatedly found.

Bacteria↗
PubMed1991

Detection of Helicobacter pylori in stomach tissue by use of a monoclonal antibody.

Monoclonal antibodies were produced against an acid glycine extract of Helicobacter pylori ATCC 43504T. One of these appeared to be specific for H. pylori; it recognized all H. pylori isolates by an indirect immunofluorescence assay (IIF) but it did not cross-react with the other strains tested, including different species of the genera Helicobacter, Campylobacter, and Wolinella. Different strains of members of the families Enterobacteriaceae and Pseudomonadaceae or other gram-negative bacteria tested also gave negative reactions. Indirect immunofluorescence assay of antral biopsy specimens identified 54 of 56 infected patients (96.4%), and it may be able to detect nonviable organisms after antibiotic therapy.

Acridines↗
PubMed1991

[Nitrates in the drinking water and cancer].

Nitrates originating from food and particularly from water are supposedly precursors of carcinogenic N-nitroso compound (NOC) formed within the organism. According to Correa and al. these transformations could be a consequence of bacterial gastric pullulation resulting from certain hypochlorhydric conditions. Much epidemiological research has tried to establish a relationship between exposure to nitrates in drinking water and cases of gastric cancer. The present article deals with research into this relationship in France, in a region where the rate of nitrates in water supplies is among the highest. Death statistics (from cancers of the digestive and urinal tracts) are issued by INSERM and these of the population by INSEE. Towns are classified according to nitrate concentration and the number of deaths is established according to tumour detection by sex and age. Research into death rate divergencies is found by chi 2 and the correlated coefficient. The average relative risk for any age group is calculated for all types of cancer. Research on frequency is carried out from tumour records. Comparative frequency rates are established by direct standardisation according to the structural age of any one European population. Results are analysed in relation to (1) mortality rates and (2) incidence rates. (1) None of the cancers studied, of the digestive or urinary systems, whatever the age on sex, is significantly linked to the quantity of nitrates in water supplies. When all these cancers are taken into account, the death rate does not vary significantly for increasing concentration of nitrates. Towns exceeding the maximum concentration permitted by law do not have a higher mortality rate than other towns.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Anti-Helicobacter pylori IgG levels in abattoir workers.

The aim of our study was to detect antibodies against Helicobacter pylori (H. pylori) in abattoir workers whose activity was variable (pig, poultry-carcasses, poultry-intestinal organs treatment). An adsorption of all sera with H. pylori and Campylobacter species known to be ubiquitous and responsible for zoonosis was included in the ELISA reaction to eliminate possible cross-reactions between these species. Statistically higher specific titres of IgG antibodies against H. pylori were observed in men and women who had only worked for 1 or 2 years versus matched controls, indicating a possible transmission of H. pylori from animal to man. The role of poultry or pigs as contaminants alone or in association remains to be determined.

Abattoirs↗
PubMed1991

[Nitrates in drinking water and cancer].

Nitrates originating from food and particularly from water are supposedly precursors of carcinogenic N-nitroso compound (NOC) formed within the organism. According to Correa and al. these transformations could be a consequence of bacterial gastric pollution resulting from certain hypochlorhydric conditions. Much epidemiological research has tried to establish a relationship between exposure to nitrates in drinking water and cases of gastric cancer. The present article deals with research into this relationship in France, in a region where the rate of nitrates in water supplies is among the highest. Death statistics (from cancers of the digestive and urinal tracts) are issued by INSERM and these of the population by INSEE. Towns are classified according to nitrate concentration and the number of deaths is established according to tumour detection by sex and age. Research into death rate divergencies is found by chi 2 and the correlated coefficient. The average relative risk for any age group is calculated for all types of cancer. Research on frequency is carried out from tumour records. Comparative frequency rates are established by direct standardisation according to the structural age of any one European population. Results are analysed in relation to (1) mortality rates and (2) incidence rates. (1) None of the cancers studied, be they of the digestive or urinary systems, whatever the age on sex, is significantly linked to the quantity of nitrates in water supplies. When all these cancers are taken into account, the death rate does not vary significantly for increasing concentration of nitrates. Towns exceeding the maximum concentration permitted by law do not have a higher mortality rate than other towns. The overall can incidence rate in the Nord-Pas-de-Calais regions of France is 11.8 per 100,000 inhabitants. The average European rate is 18.3 per 100,000 for men in the Nord region and 20.5 in the Pas-de-Calais; for women, 5.9 and 7.2 respectively. These rates are comparable to those in other French regions. The incidence rate for gastric cancer is not significantly different for inhabitants of towns exposed to water containing more or less than 50 mg/l. The absence of links between cancer and nitrates water research into possible methodological expedients necessary. A certain number of factors (consumer habits, diet, population mobility) can, for the same concentration of nitrates, modify the actual quantity consumed, and so the corresponding long-term risk. However, no inverse effect of these factors which would be susceptible to counter the link to the extent of concealing it, is know for the moment.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1989

Isolation and characterization of monoclonal antibodies against alkaline phosphatase of Pseudomonas aeruginosa.

Monoclonal antibodies against the alkaline phosphatase of Pseudomonas aeruginosa were produced from spleen cells of BALB/c mice primed with purified alkaline phosphatase of P. aeruginosa ATCC 10145 and SP20/Ag-14 myeloma cells. The eight stable clones established produced antibodies that reacted by enzyme-linked immunosorbent and indirect immunofluorescence assays with all bacterial strains of P. aeruginosa, including the 17 serotypes and two nontypable strains. Three of the clones cross-reacted only with some Pseudomonas species of the rRNA homology group I defined by N. J. Palleroni (in N. R. Krieg and J. G. Holt, ed., Bergey's Manual of Systematic Bacteriology, 8th ed., p. 140-218, 1984). The other clones also interacted with other species, including Pseudomonas acidovorans and Xanthomonas maltophilia. Because other species of the genera Aeromonas and Acinetobacter and species of the family Enterobacteriaceae were not detected by these monoclonal antibodies, the antibodies could be used as reagents for routine detection of P. aeruginosa in clinical specimens. Interactions of the antibodies with other Pseudomonas species such as P. fluorescens and P. stutzeri are not important, since these species are susceptible to the same antipseudomonal agents.

Alkaline Phosphatase↗
PubMed1989

Alkaline phosphatase capture test for the rapid identification of Escherichia coli and Shigella species based on a specific monoclonal antibody.

A specific monoclonal antibody for Escherichia coli and Shigella sp. alkaline phosphatase was used in an immunocapture assay and allowed identification of E. coli either in culture isolates or directly in clinical specimens. The assay was easy and required only four steps: (i) alkaline phosphatase was released within 10 min by using a gentle lysis procedure, (ii) cell lysates were transferred to antibody-coated tubes for 45 min, (iii) p-nitrophenyl phosphate substrate was added, and (iv) alkaline phosphatase activity was detected in a microsample spectrophotometer at 410 nm. This immunocapture assay was highly specific: only one false-positive reaction was observed with a Klebsiella pneumoniae lysate among the 205 non-E. coli strains tested. The assay was sensitive, detecting 10(7) CFU/ml from culture isolates or 10(5) CFU/ml from urine specimens which had first been grown in phosphate-limiting medium for 2 h. At these bacterial concentrations, the percentages of detected E. coli were high: 91% for blood cultures, 95.4% for culture isolates, and 96.8% for urine specimens.

Alkaline Phosphatase↗
PubMed1989

[Molecular markers and identification of Campylobacter pylori strains].

Campylobacter pylori was studied to define the classification of species and the typing of strains. The mol p. 100 G + C of 17 strains ranged from 34.1 to 37.5 (average value: 35.2; SD: 1.0). The strains are closely related (80 to 100 p. 100 DNA/DNA relatedness) and to the type strain NCTC 11367. The endonuclease restriction profiles were specific of strains. DNA analysis (REA) is a sensitive method in pathogenic and epidemiological studies.

Biomarkers↗
PubMed1988

[Pharmacokinetics of cefotaxime in cirrhotic patients with or without ascites].

Pharmacokinetic values of cefotaxime were measured in 12 cirrhotic male patients (6 without ascites and 6 with ascites) after intravenous injection of a single 2 gram dose of the antibiotic. In patients without ascites elimination of the drug was about the same as in normal subjects or control patients, although clearance was increased. In patients with ascites, the drug elimination half-life was significantly more prolonged (7.5 +/- 3.9 h versus 1.3 +/- 0.4 h, P less than 0.01) and the drug clearance was significantly lower (193.6 +/- 92.4 ml/min versus 475.8 +/- 152.2 ml/min, P less than 0.01) than in the other group. The accumulation of cefotaxime in these patients produced concentration in the ascites fluid that were above the critical therapeutic values for about 20 hours.

Ascites↗
PubMed1988

[A method of bacterial count by epifluorescence with acridine orange. Application to skin biopsies performed in burnt patients].

Acridine orange was used for staining and counting micro-organisms obtained from 136 skin biopsies performed in burned patients. The number of organisms per gram of tissue was compared to the number of colony-forming-units (CFU) calculated from cultures of the same biopsies. The staining method was positive in 97 per cent of septic samples, and in 25 per cent of these it proved more sensitive than bacterial cultures, with a 100 to 1000-fold greater number of pathogens detected. Acridine orange also demonstrated bacteria in 69 biopsies which remained sterile after culture. In some cases, the same bacterial species was found in other samples taken a few days later.

Acridine Orange↗
PubMed1988

Susceptibilities to antibiotics and antiseptics of new species of the family Enterobacteriaceae.

One hundred and sixty-nine strains of new species of the family Enterobacteriaceae, isolated mainly from the environment, were tested to determine their susceptibilities to 13 antibiotics and 4 antiseptics or disinfectants. All the species were susceptible to aminoglycosides, doxycycline, and trimethoprim but were resistant to chloramphenicol. Susceptibility to beta-lactams varied more among the strains. However, all the strains were cefotaxime susceptible, apart from some Buttiauxella agrestis strains for which MICs were greater than 256 micrograms/ml. The antiseptic MBCs were similar to those published elsewhere for species of the Enterobacteriaceae of clinical origin. No resistance to chlorhexidine was observed. On the other hand, the environmental strains presented a greater resistance to active chlorine than did the reference strains.

Anti-Bacterial Agents↗
PubMed1987

A rapid chemical procedure for isolation and purification of chromosomal DNA from gram-negative bacilli.

A rapid and simple method for preparing chromosomal DNA from gram-negative bacilli is presented. It is based on the alkaline (NaOH 0.03 M) lysis of cell walls. The resulting emulsion is purified by proteinase K (0.625 mg/g of wet wt), SDS, and the deproteinizing agent (chloroform isoamyl alcohol). The purity, molecular nature, and yield of DNA obtained by the present method are compared with those of DNA extracted by Marmur's procedure and a Marmur's modified procedure. We have developed and standardized this original method to isolate double-stranded DNA, free of proteins and RNA contamination and with a significantly higher yield of DNA than the two other methods. This procedure is particularly useful for strains with low growth and can be applied in every field concerned with DNA analysis.

Cell Wall↗