Third Belgian multicentre survey of antibiotic susceptibility of anaerobic bacteria.
OBJECTIVE
To collect recent data on the susceptibility of anaerobes and to compare them with results from previous studies.


METHODS
Four hundred and forty-three anaerobic clinical isolates from various body sites were prospectively collected from October 2003 to February 2005 in nine Belgian hospitals. MICs were determined for nine anti-anaerobic and three recently developed antibiotics.


RESULTS
Most gram-negative bacilli except Fusobacterium spp. were resistant to penicillin. Piperacillin/tazobactam, metronidazole, chloramphenicol, meropenem and amoxicillin/clavulanic acid were very active against all groups, but only 86% of Bacteroides fragilis group strains were susceptible to the latter. Cefoxitin, cefotetan and clindamycin were less active. In particular, only 62%, 52% and 48% of B. fragilis group strains were susceptible, respectively. Clindamycin shows a continuing decrease in activity, as 83% were still susceptible in 1987 and 66% in 1993-94. Anti-anaerobic activity of the new antibiotics is interesting, with MIC50 and MIC90 of 1 and >32 mg/L for moxifloxacin, 2 and 4 mg/L for linezolid and 0.5 and 8 mg/L for tigecycline.


CONCLUSIONS
The susceptibility of anaerobic bacteria remains stable in Belgium, except for clindamycin, which shows a continuous decrease in activity. However, for each of the tested antibiotics, at least a few resistant organisms were detected. Consequently, for severe infections involving anaerobic bacteria, it could be advisable to perform microbiological testing instead of relying on known susceptibility profiles. Periodically monitoring background susceptibility remains necessary to guide empirical therapy.
Wybo
Ingrid
I
Academisch Ziekenhuis Vrije Universiteit Brussel, 1090 Brussels, Belgium. ingrid.wybo@az.vub.ac.be
Piérard
Denis
D
Verschraegen
Inge
I
Reynders
Marijke
M
Vandoorslaer
Kristof
K
Claeys
Geert
G
Delmée
Michel
M
Glupczynski
Youri
Y
Gordts
Bart
B
Ieven
Margaretha
M
Melin
Pierrette
P
Struelens
Marc
M
Verhaegen
Jan
J
Lauwers
Sabine
S
D019980:Amoxicillin-Potassium Clavulanate Combination / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001372:Aza Compounds / Q000494:pharmacology; D001421:Bacteria, Anaerobic / Q000187:drug effects*; D002440:Cefoxitin / Q000494:pharmacology; D024841:Fluoroquinolones; D008826:Microbial Sensitivity Tests; D000077266:Moxifloxacin; D010406:Penicillins / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology; D001618:beta-Lactamases / Q000032:analysis
D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D010406:Penicillins; D011804:Quinolines; D002440:Cefoxitin; D019980:Amoxicillin-Potassium Clavulanate Combination; D001618:beta-Lactamases; D000077266:Moxifloxacin