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R Cluzel

Publications and source records attributed to R Cluzel.

At least 73 records · Page 4Linked to original sources
PubMed1975

[Should resistance to methicillin of RH mutant staphylococci be necessarily attributed to cephalosporins?].

The resistance to cephalosporins of 48 heterogeneous methicillin-resistant strains ("RH" mutants) of Staphylococcus pyogenes var. aureus is studied in vitro with various methods: sensitivity discs test on Mueller-Hinton medium with 5 per cent NaCl at 37 degrees C; M.I.C. in solid medium by spots medium with two inocula: a light inoculum (10(7) bacterial/ml) and a heavy inoculum (10(9) bacteria/ml). With light inoculum all strains have M.I.C. to cephaloridin less than 2 meg/ml and seem sensitive. With heavy inoculum 45 sc. equal or superior to 64 meg/ml and then are resistant. These resistances occur after 3 degrees C. The varied methods of detection of mutants to cephalosporins are discussed in this paper.

Cephalosporins↗
PubMedDate not supplied

A new colonization factor antigen (CFA/III) produced by enteropathogenic Escherichia coli O128:B12.

Fourteen enteropathogenic Escherichia coli strains isolated in the Dakar area (Senegal) from cases of diarrhoea in children were tested for the presence of adhesive factors. None of these strains possessed colonization factor antigens CFA/I or CFA/II, but one strain (strain 1373) presented a haemagglutination (HA) type similar to that of the CFA/I reference strain and failed to be agglutinated with CFA/I antiserum. Strain 1373 adhered strongly in vitro to human enterocyte brush borders. HA was not inhibited by D-mannose (which inhibits HA of type 1 pili) or by N-acetylneuraminic acid (which inhibits HA of CFA/I and CFA/II). HA and the adhesion of strain 1373 were inhibited by anti-CFA/III serum but not by anti-CFA/I or anti-CFA/II sera. The colonization factor antigen (CFA) of strain 1373 is a new antigen (which we propose to call CFA/III) and is distinct from CFA/I, CFA/II and type 1 pili. CFA/III has a protein subunit of molecular weight of about 16,000.

Agglutination Tests↗
PubMedDate not supplied

Characterization of a beta-lactamase from Pasteurella multocida.

A bovine strain of Pasteurella multocida was found to produce a beta-lactamase. The minimal inhibitory concentrations of amoxicillin (128 mg/l) and ticarcillin (512 mg/l) were high for this strain. The enzyme was periplasmic and produced constitutively, and there was no obvious permeability barrier. This enzyme had a TEM-substrate profile, and no inhibition was detected with antisera (anti-TEM-1, anti-TEM-2). The apparent isoelectric point was estimated at 8.8.

Amoxicillin↗
PubMedDate not supplied

[The role of heavy metals and their derivatives in the selection of antibiotics resistant gram-negative rods (author's transl)].

The authors have studied 116 Gram-negative strains, 27 of which were sensitive to antibiotics and 89 showed multiple resistance. The MIC of mercury chloride, mercuric nitrate and of an aqueous solution of mercuresceine were much higher in the case of the sensitive strains. The transfer of resistance to mercury, which has been achieved in 56% of cases, was always accompanied by transfer of resistance to the antibiotics. The MIC of phenylmercury borate, mercurothiolic acid and other heavy metals (such as: cobaltous nitrate, silver nitrate, cadmium nitrate, nickel nitrate, zinc nitrate, copper sulphate and sodium arsenate) are approximatively the same for all strains. The normal concentrations of mercury in nature are lower than the rate of microbial selection. But in areas of accumulation, particularly in biological chains or in hospitals, the mercury compounds could play a part in the selection of antibiotic resistant Gram-negative bacteria.

Anti-Bacterial Agents↗