University of Pennsylvania Medical Center Guidelines for Antibiotic Use

Antimicrobial Susceptibilities of Obligately Anaerobic Bacteria Bacterial Isolates Collected from 2009 to 2010

% Susceptible - Etest, CLSI M11-A8 and M100-S23 guidelines

Bacterium No. Tested Pen G A/C Mero Metro Clinda Vanco
 Breakpoint    ≤0.5 ≤4/2 ≤4 ≤8 ≤2 ≤1a
B. fragilis group 76 NTb 96 100 99 41 NTb
Clostridium 30 97c 100 NT 100 47 NT
Gram-pos cocci (Peptostreptococcus, Finegoldia) 46 100 100 NT NTb 87 98
Pigmented Gram-neg rods (Prevotella, Porphyromonas)

12

 

NTb 100 100 100 75 NTb
Fusobacterium 6 6d 6d NT 6d NT NT
P. acnes 79 100 NT NT NTb 88 100
Veillonella 4 2d 4d NT 4d 4d NTb

Pen G - Penicillin G, A/C - Amoxicillin/clavulanate, Mero - Meropenem, Metro - Metronidazole, Clinda - Clindamycin, NT - not tested,

a, Vancomycin breakpoint extrapolated from viridans streptococci; b, resistance common to this drug for this bacterium and drug not tested; c, the penicillin MIC of 1 Clostridium spp. isolate was 1 mg/L, and would likely respond to high dosage penicillin therapy - the slightly greater activity of amoxicillin/clavulanate is related to its higher breakpoint and not because of the inactivation of a beta-lactamase; d, number of isolates rather than % are reported because of low N

11/15/13 P. Edelstein

older data for 2007-2008, 2006, 2004 and 2001

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