Previous Article | Next Article ![]()
Antimicrobial Agents and Chemotherapy, November 1999, p. 2607-2611, Vol. 43, No. 11
Department of Microbiology, Centre
Hospitalier Universitaire Saint-Antoine, Assistance
Publique-Hôpitaux de Paris, Université Paris VI, Paris 12, France,1 and Department of Microbiology,
University of Louvain, Brussels, Belgium2
Received 7 December 1998/Returned for modification 24 March
1999/Accepted 18 August 1999
Glycopeptides (vancomycin and teicoplanin) and metronidazole are
the drugs of choice for the treatment of Clostridium
difficile infections, but trends in susceptibility patterns have
not been assessed in the past few years. The objective was to study the MICs of glycopeptides and metronidazole for unrelated C. difficile strains isolated in 1991 (n = 100) and
in 1997 (n = 98) by the agar macrodilution, the
E-test, and the disk diffusion methods. Strain susceptibilities to
erythromycin, clindamycin, tetracycline, rifampin, and chloramphenicol
were also determined by the ATB ANA gallery (bioMérieux, La
Balme-les-Grottes, France). The MICs at which 50% of isolates are
inhibited (MIC50s) and MIC90s of glycopeptides
and metronidazole remained stable between 1991 and 1997. All the
strains were inhibited by concentrations that did not exceed 2 µg/ml
for vancomycin and 1 µg/ml for teicoplanin. Comparison of MICs
determined by the agar dilution method recommended by the National
Committee for Clinical Laboratory Standards and the E test showed
correlations (±2 dilutions) of 86.6, 95.9, and 99% for metronidazole,
vancomycin, and teicoplanin, respectively. The E test always
underestimated the MICs. Strains with decreased susceptibility to
metronidazole (MICs,
0066-4804/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
Antimicrobial Susceptibilities and Serogroups of
Clinical Strains of Clostridium difficile Isolated in France
in 1991 and 1997
8 µg/ml) were isolated from six patients
(n = 4 in 1991 and n = 2 in 1997).
These strains were also detected by the disk diffusion method (zone
inhibition diameter,
21 mm); they belonged to nontoxigenic serogroup
D (n = 5) and toxigenic serogroup H
(n = 1). Decreased susceptibility to erythromycin
(MICs,
1 µg/ml), clindamycin (MICs,
2 µg/ml), tetracycline
(MICs,
8 µg/ml), rifampin (MICs,
4 µg/ml), and chloramphenicol
(MICs,
16 µg/ml) was observed in 64.2, 80.3, 23.7, 22.7, and 14.6%
of strains, respectively. Strains isolated in 1997 were more
susceptible than those isolated in 1991, and this trend was correlated
to a major change in serogroup distribution. Periodic studies are
needed in order to detect changes in serogroups and the emergence of
strains with decreased susceptibility to therapeutic drugs.
*
Corresponding author. Mailing address: Service de
Bactériologie-Virologie, Hôpital Saint-Antoine, 184, rue du
Faubourg Saint-Antoine, 75 571 Paris Cedex 12, France. Phone: 33 (1) 49 28 29 10. Fax: 33 (1) 49 28 24 72. E-mail:
frederic.barbut{at}sat.ap-hop-paris.fr.
This article has been cited by other articles:
| Clin. Vaccine Immunol. | Clin. Microbiol. Rev. |
|---|---|
| J. Clin. Microbiol. | ALL ASM JOURNALS |