The in vitro susceptibility of 155 strains of anaerobic bacteria to five cephalosporin antibiotics was tested. Cefoxitin was the most active against 33 isolates of Bacteroides fragilis; 82% of the strains were sensitive at 16 mug/ml. At 64 mug/ml cefazolin and cephaloridine were also generally effective. Cephalothin and cephalexin were relatively inactive versus B. fragilis. Cefoxitin, cephalor...

Detection of AmpC-mediated resistance in Gram negative organisms poses a problem due to misleading results in phenotypic tests. There are no recommended guidelines for detection of this resistance mechanism and there is a need to address this issue as much as the detection of extended spectrum beta lactamases (ESBLs) since both may co-exist and mask each other. Several methods have been used to...

The in vitro susceptibility of 157 anaerobic bacteria to imipenem was compared with that to cefoxitin, latamoxef (moxalactam) and clindamycin. The isolates were cultured from clinical specimens submitted to Tufts Anaerobic Laboratory between January 1981 and March 1983. Two strains of Bacteroides fragilis only, were highly resistant to imipenem. The incidence of cefoxitin resistance in the Bact...

We evaluated a widely used culture-based method for detection of livestock-associated meticillin-resistant Staphylococcus aureus (LA-MRSA) in samples collected from pigs and the environment inside pig stables in Denmark and Norway. Selective enrichment in tryptic soy broth containing cefoxitin and aztreonam led to a high ratio of false-negative results (26%; 57/221). On this basis, we recommend...

  BackgroundandObjectives:RapidandaccuratedetectionofmethicillinresistantStaphylococcus aureus (MRSA) is an important role of clinical microbiology laboratories to avoid treatment failure. The aim of this study was to compare conventional methods against the E-test minimum inhibitory concentration (MIC) method to determine the best phenotypic method. Materials a...