Antimicrobial resistance determinants are indicated in red. The 2,589-bp repA/C region includes the complete repA gene, which is involved in plasmid this website replication and incompatibility group determination. floR is a 1,050-bp region spanning almost the complete floR gene coding for chloramphenicol resistance. The insertion of the CMY island into the plasmid backbone between traC
and traA was evaluated Selleckchem Cilengitide by PCR D and PCR G for the right junction, and by PCR A and B for the left junction (see Additional file 1, Table S1, Figure 4 and Results). Two regions included in the IncA/C plasmid PCR typing scheme proposed by Welch et al.  were analyzed. The 1,431-bp Region 7 (R-7) includes the bet gene coding for a phage recombination protein. Region 8 (R-8) is a DNA fragment of 1,600 bp that contains the dcm gene coding for a DNA methylase. The presence of the mercury resistance operon (mer), frequently associated with the Tn21 transposon [7, 8], was evaluated by the amplification of a 2,185-bp region spanning from merA to merT. The presence selleck inhibitor of IP-1 (dfrA12, orfF and aadA2) was assessed using primers targeting its conserved sequences. Figure 4 Schematic diagram of the CMY regions
of Newport and Typhimurium. Panel A shows a schematic diagram of the CMY region of plasmid pSN254 present in Newport , which is composed of an inverted repeat CMY element between the traA and traC genes (unfilled arrows indicate the open reading frames, and the bla CMY-2 gene is in red). Panel B shows the CMY region of the Typhimurium ST213 strain YUHS 07-18 containing a single CMY element. Truncated
genes are indicated by a line crossing the open reading frame arrows. The PCR amplifications designed to map the CMY region are indicated by double arrowheads under the diagrams (see Additional file 1, Table S1 and Results). The PCRs used to screen the CMY junctions are indicated by black double arrowheads. Ten strains representing different geographic locations, years and sources were chosen Dolutegravir supplier and their regions analyzed in the PCR screening were sequenced (Additional file 2, Table S2). The sequences were identical for all the plasmids (both CMY+ and CMY-); only the mer region showed a single nucleotide substitution (Additional file 2, Table S2). It was surprising that even intergenic regions and third codon positions were invariable. BLAST searches showed that our sequences are identical (100% identity) to the IncA/C plasmids pAR060302 (E. coli), peH4H (E. coli), pAM04528 (Newport) and pSN254 (Newport); are closely related (99-98%) to the IncA/C plasmids pIP1202 (Yersinia pestis), pYR1 (Yersinia ruckeri), pP91278 (Photobacterium damselae), pP99-018 (P. damselae) and pMRV150 (Vibrio cholerae); and are related (88-89% identity) to pRA1 (Aeromonas hydrophila) [5–10]. The repA gene displays the repA/C 2 allele described for other IncA/C CMY+ plasmids . Call et al.