Search PubMed⌕ Search

Biomedical subjects

A Dublanchet

Publications and source records attributed to A Dublanchet.

54 records · Page 3Linked to original sources

Transfer of multiple antibiotic resistance between subspecies of Bacteroides fragilis.

Resistance to clindamycin, erythromycin, streptogramins, and tetracycline was shown to be transferable from a clinical isolate of Bacteroides fragilis subspecies distasonis to a sensitive strain of B. fragilis subspecies fragilis. Resistance to clindamycin, erythromycin, and streptogramins was transferable from a clinical isolate of B. fragilis subspecies fragilis to the sensitive strain of B. fragilis subspecies fragilis. Except for tetracycline, resistance to all of these antibiotics was spontaneously curable en bloc at a frequency of approximately 10(-2). These results suggest that resistance to these antibiotics is determined by a plasmid.

Anti-Bacterial Agents↗

[The pneumococcal infection in a general hospital of a parisian suburb: a prospective study in Villeneuve-Saint-Georges hospital (author's transl)].

The authors have carried during one year, in the hospital of Villeneuve-Saint-Georges, a prospective study on 229 cases of pneumococcal infections with bacteriological findings. They emphazise the frequency, the high-exposed groups and the gravity of these infections despite of the antibiotherapy. The emergence of multiply resistant pneumococcus makes out another argument for proposing a preventive vaccination taking notice of the most frequent serotypes found in France.

Adolescent↗

[Pneumococcal serotyping. Multicentric inventory in hospital. Years 1977-1978 (author's transl)].

For a period of 17 months, 670 pneumococci, mostly isolated in the Paris area, have been typed with contercurrent-immunoelectrophoresis ; 338 of them come from cases of pneumonia, bacteremia, meningitis and acute otitis media. An important regrouping of the most frequent serotypes among the 83 known serotypes makes possible a vaccinal prophylaxis. The tetradecavalent vaccine which is now for sale in USA gives, in the four main pathologies of this enquiry, a coverage superior to 80 percent. Choosing the 14 most frequent serotypes of the four main pathologies of their data the authors propose the following vaccinal formula : 1, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 18, 19, 23.

Adolescent↗

[Actinomyces odontolyticus, first study in France].

The authors report the detailed study of a strain of Actinomyces odontolyticus isolated from a pleural liquid. Gas-liquid chromatography can specify the biochemistral metabolism of the germ and set off an endocellular lipidolytic activity.

Actinomyces↗

Plasmid-mediated pristinamycin resistance. PAC IIA: a new enzyme which modifies pristinamycin IIA.

A wild strain of Staphylococcus aureus which inactivates a wide variety of antibiotics has been found to inactivate pristinamycin IIA, an antistaphylococcal antibiotic. This phenomenon has been demonstrated to be plasmid mediated. The plasmid directs the biosynthesis of an acetyltransferase which is able to O-acetylate the drug. We propose to call the new enzyme PAC (IIA): Pristinamycin acetyltransferase.

Acetyltransferases↗

[Resistance to streptogramin antibiotics in "Staphylococcus aureus" (author's transl)].

Pristinamycin and virginiamycin, two antibiotics belonging to the streptogramin group, are widely used in France against staphylococcal infections. They are mixtures of two different active compounds, pristinamycin I and II, virginiamycine S and M. The present study describes five clinical isolates of Staphylococcus aureus with unusual resistance to these antibiotics. This resistance, whose level is variable according to the strains, concerns both compounds of these antibiotics. It is lost at high frequency spontaneoulsy or after treatment by curing agents, suggesting that the resistance is plasmid mediated. The drug inactivation by the resistant strains supports the hypothesis of an enzymatic mechanism of resistance. Furthermore, this new resistance seems to be linked, in some strains, to either of the two aminoglycoside resistance patterns recently described in S. aureus.

Anti-Bacterial Agents↗

[ANT(4')I: a new aminoglycoside nucleotidyltransferase found in "staphylococcus aureus" (author's transl)].

A new nucleotidyltransferase has been obtained from clinical isolates of kanamycin, amikacin, tobramycin, neomycin and lividomycin resistant strains of Staphylococcus aureus. The enzyme has been purified by affinity chromatography then characterized in a kinetic and physicochemical point of view. The results obtained support that the target of this enzyme is the 4'-hydroxyl group of a number of aminoglycosides. We propose to call it ANT(4')I.

Aminoglycosides↗

Vancomycin prophylaxis and intraocular contamination during cataract surgery.

PURPOSE: To investigate the effect of vancomycin added to the intraocular irrigation solution to prevent anterior chamber contamination during phacoemulsification. SETTING: Centre Hospitalier, Villeneuve-Saint-Georges, France. METHODS: A group of 372 patients having cataract extraction by phacoemulsification was divided into two consecutive, nonrandomized groups. The first group (n = 190) was a control; there was no antibiotic in the irrigation solution. The second group (n = 182) received vancomycin in the irrigation solution. Intraocular fluid was aspirated at the end of surgery and injected into a blood culture bottle to evaluate bacterial contamination of the anterior chamber. RESULTS: There was no between-group difference in bacterial intraocular contamination. Eight samples in the first group were contaminated and nine in the second group. All contaminants were gram-positive vancomycin-sensitive organisms. CONCLUSIONS: Adding vancomycin to the intraocular irrigation solution during cataract surgery had no effect on the occurrence of intraocular contamination as evaluated by anterior chamber taps.

Anterior Chamber↗

Ocular penetration kinetics of fosfomycin administered as a one-hour infusion.

The penetration of fosfomycin in aqueous humour was studied in 21 patients who were to undergo cataract surgery. All patients received 4 grams of fosfomycin as an infusion lasting one hour. Concentrations of the drug in aqueous humour were measured 1, 2, 4, 6 and 12 hours after the start of infusion. Drug concentrations in aqueous humour and serum were measured by HPCE (High Performance Capillary Electrophoresis). The aqueous humour concentration at one hour was 11.46 mg/l +/- 2.12. Peak concentration was 14.63 mg/l +/- 5.54, reached two hours after the infusion. Concentrations were high until 6 hours and remained significant at 12 hours. These results confirm the excellent diffusion of fosfomycin in aqueous humour, with high levels at 12 hours. They justify its use in intraocular infections, by infusions repeated every eight hours, to maintain concentrations above the MIC 90 for organisms usually susceptible to the drug.

Adolescent↗

A gentamycin resistance plasmid in Staphylococcus aureus.

Drug resistance in Staphylococcus aureus is frequently mediated by non-chromosomal DNA molecules referred to as R plasmids. So far, resistance to aminosidic antibiotics was observed with streptomycin [8] and kanamycin-neomycin [3]. Resistance to gentamycin has not been reported in a recent survey by Lacey [7]. In this paper, we describe a strain of S. aureus resistant to gentamycin-kanamycin-tobramycin-sisomycin, and experiments which suggest that the genetic determinant of these resistance characters is plasmid borne.

Anti-Bacterial Agents↗

A collaborative study of French laboratories to assess any evolution of antibiotic resistance within the Bacteroides fragilis group.

Antibiotic susceptibility testing of anaerobes by a same methodology allows the authors to draw up suggestions about the evolution of antibiotic resistance within the B. fragilis group. Cefoxitin resistance rates were stable until 1985 and were slowly increasing later. Until 1985 piperacillin was able to inhibit all tested strains. In 1987 the two groups noticed an increasing resistance to piperacillin (4 to 9%). During the 1970's clindamycin resistance was a minor event (less than 1%) then the resistance rate increased rapidly to 10% in 1980. MICs determinations from 1981 to 1985 demonstrated well that clindamycin resistance was stable at this 10% rate. Since 1987 the clindamycin resistance was again increasing and reached respectively 14 to 19% for the two groups of investigators. Metronidazole has kept a good activity against Bacteroides fragilis group strains but some strains with reduced susceptibility (MIC 2 to 8 mg/l) have been described since 1983. Three strains with MIC greater than 8 mg/l were recently described by one of the groups. Until 1987, the clavulanic amoxicillin combination was able to inhibit all strains of the B. fragilis group but only imipenem remained still active on all investigated strains with no change at all for the values of MIC50 and MIC90 determined by the investigators of this study. All these results emphasize the need for periodical surveys within the B. fragilis group in each country.

Bacteroides fragilis↗

["In vitro" susceptibility of some aerobic and anaerobic bacteria to three 5-nitro-imidazole derivatives: metronidazole, ornidazole and tinidazole (author's transl)].

As shown earlier, the three drugs are effective against most anaerobic bacteria. However, with Bacteroides fragilis the geometric mean MIC of metronidazole (0.43 microgram/ml), ornidazole (0.37 microgram/ml) and tinidazole (0.20 microgram/ml) are statistically different. Moreover, and contrary to generally accepted opinion, some aerobic bacteria such as Moraxella and Bacillus can be susceptible to nitro-imidazoles. The results suggest another mechanism for the action of nitro-imidazoles, different from that previously described. This underscores the major role of the reduction of the nitrogroup by a low-redox-potential. Two strains of strictly anaerobic bacteria show a relative resistance in the microaerophilic zone.

Aerobiosis↗