University of Pennsylvania Clinical Microbiology

Antimicrobial Susceptibilities of Obligately Anaerobic Bacteria Bacterial Isolates Collected in 2017

% Susceptible - Etest, M100-S27 guidelines

Bacterium No. Tested Pen G A/C* Mero Metro Clinda Vanco
 Breakpoint    ≤0.5 ≤4/2 ≤4 ≤8 ≤2  
Bacteroides fragilis complex 29 R 82 96 100 28  
Clostridium perfringens 5 5/5 NT NT 5/5 4/5  
Clostridium spp, not perfringens 4 4/4 NT NT 4/4 1/4  
Finegoldia magna 9 9/9 NT NT NT 9/9  
Prevotella spp.

15

NT 100 100 100 13  
Fusobacterium spp. 9 9/9 9/9 9/9 9/9 9/9  
Propionibacterium acnes 14 100 NT NT R 100 6/6**
Propionibacterium spp. other than P. acnes 6 6/6 NT NT R 3/6  
Parvimonas micra 13 100 NT NT NT 85  
Peptoniphilus asaccharolyticus 11 100 NT NT NT 64  
Veillonella spp. 13 46 100 100 100 92  

Pen G - Penicillin G, A/C - Amoxicillin/clavulanate, Mero - Meropenem, Metro - Metronidazole, Clinda - Clindamycin, Vanco - vancomycin, NT - not tested, R intrinsic resistance

* The current CLSI amoxicillin/clavulanate breakpoint of ≤4/2 is probably too high and is under reevaluation. An oral dosage of 875/125 given twice daily achieves serum levels for adequate pd target attainment (40% time above the MIC) of amoxicillin/clavualanate MICs of 2/2 or lower. 12% of the amox/clav "susceptible B. fragilis complex have amox/clav MICs of 4 mg/L, as do 8% of "susceptible" Veillonella spp. All amox/clav "susceptible" Prevotella spp and Fusobacterium spp have amox/clav MICs ≤2/2 mg/L

** All isolates had vancomycin MICs <2 mg/L, the epidemiologic cutoff value (ECV). An isolate with a drug MIC<ECV does not necessarily mean that it is drug susceptible. See the ECV webpage for more details.

 

9/12/2017 P. Edelstein

older data for 2014, 2009-2010, 2007-2008, 2006, 2004 and 2001

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