PMC5644516_01
PCR amplification of the variable regions of class 1 and class 2 integrons. (a) Class 1 integron-variable regions amplified using Lev5'CS and Lev3'CS primers. Lane 1: No template; Lane 2: E. coli strain 042 bearing an aadA cassette within a class 1 integron; Lane 3: E. coli strain 17-2 bearing the dfrA1-sat-aadA cassette sequence within a class 2 integron; Lane 4: K. pneumoniae subsp. pneumoniae isolate K01 from this study; Lane 5: 1 kb Ladder plus (Invitrogen). Marker size fragments are indicated to the right of the gel in kilobase pairs. (b) Class 2 integron-variable regions amplified using hep51 and hep74 primers with samples shown in (a) loaded on to the gel. (c) Cassette content and orientation of the K01 integron amplified in (A), as predicted from the DNA sequence.
AJLM-1-16-g001.jpg
PMC5644516_01_AJLM-1-16-g001.jpg
F0001
As shown in Figure 1, we were able to determine that the strain harboured a class 1, but not a class 2 integron.
PCR amplification of a ctx allele from K. pneumoniae subsp. pneumoniae isolate K01 from this study. Lane 1: 1 kb Ladder plus (Invitrogen). Lane 2: K01. Lane 3: ESBL-negative E. coli strain 042. Lane 4: No template. Marker size fragments are indicated to the left of the gel in Kilobase pairs. In the absence of a positive control, the identity of the band amplified from strain K01 was determined by sequencing.
AJLM-1-16-g002.jpg
PMC5644516_01_AJLM-1-16-g002.jpg
F0002
The resulting 550 bp product shown in Figure 2 was sequenced and found to be identical to the corresponding region of blaCTX-M-15.