[Detection of extended-spectrum ß-lactamase-producing Enterobacteriaceae in rectal swabs with the Mastdiscs™ ID AmpC ßLSE detection set]

Pathol Biol (Paris). 2012 Oct;60(5):e41-4. doi: 10.1016/j.patbio.2011.07.002. Epub 2011 Aug 10.
[Article in French]


Objectives: The double-disk synergy test was compared to the Mastdiscs™ ID AmpC and ESßL method for detection of ESßL production in rectal swab.

Methods: Two hundred and forty-nine rectal swabs were directly inoculated onto Mueller-Hinton plates and analyzed according to both methods.

Results: A total of 41 (16%) and 208 (84%) were positive and negative for ESßL, respectively. Twelve (29%) and 20 (49%) of the 41 rectal swabs positive for ESßL were detected after 24h of incubation with the double-disk synergy test and the Mastdiscs™ method, respectively (P=0.013). One hundred fifty-eight (76%) et 183 (88%) of the 208 rectal swabs were detected negative for ESßL after 24h of incubation with the double-disk synergy test and the Mastdiscs™ method, respectively (P<0.001). Finally, 79 (32%) and 46 (18%) rectal swabs respectively inoculated according to the double-disk synergy test and the Mastdiscs™ method were inconclusive after 24h of incubation. The better performance of the Mastdiscs™ method was due to an easier detection of cephalosporinase producing bacteria.

Conclusions: The Mastdiscs™ method is a simple phenotypic method that detects more easily ESßL and non-ESßL producing bacteria in rectal swab.

Publication types

  • Evaluation Study

MeSH terms

  • Bacterial Proteins / biosynthesis*
  • Drug Resistance, Multiple, Bacterial / genetics
  • Enterobacter / growth & development
  • Enterobacter / isolation & purification
  • Enterobacteriaceae / isolation & purification*
  • Enterobacteriaceae / metabolism
  • Enterobacteriaceae Infections / diagnosis*
  • Enterobacteriaceae Infections / microbiology
  • Humans
  • Klebsiella / growth & development
  • Klebsiella / isolation & purification
  • Microbial Sensitivity Tests
  • Microbiological Techniques / instrumentation
  • Microbiological Techniques / methods*
  • Reagent Kits, Diagnostic
  • Rectum / microbiology*
  • beta-Lactamases / biosynthesis*


  • Bacterial Proteins
  • Reagent Kits, Diagnostic
  • AmpC beta-lactamases
  • beta-Lactamases