A novel Direct MIC-gradient Strip Method to screen for antibiotic-resistant faecal Enterobacteriaceae

•MIC-gradient strips applied directly onto plated faecal samples.•Provides the MICs of the dominant Gram-negative populations directly on the plates.•Detects smaller, resistant Gram-negative faecal bacterial subpopulations with a sensitivity of 1/105.•Up to six different antibiotics assessed simultaneously on the same plate.•Enables efficient screening for resistant Enterobacteriaceae in faecal samples.

A novel method to detect resistant faecal Enterobacteriaceae was developed by applying MIC-gradient strips directly onto agar plates inoculated with faeces. The method provided the susceptibility pattern (MICs) of the dominant bacterial population directly on the plates and also detected smaller resistant subpopulations with a sensitivity of 1/105.