Article Figures & Data
Figures
- Fig. 1.
Plasmids in S. enterica serotype Typhimurium strains. (A) Plasmid DNA in S. enterica serotype Wien WZM6 (lane 1) and in six prototypic isolates of S. entericaserotype Typhimurium, strains 44 (lane 2), 516 (lane 3), 252 (lane 4), 298 (lane 5), 202 (lane 6), and 341 (lane 7). Plasmids were separated by agarose gel electrophoresis and stained with ethidium bromide. Replicas of the electropherograms shown in panel A were blotted onto nylon membrane filters and hybridized with the following probes:rep FIA (B), rep FIB (C),rep L/M (D), and an integrase gene (intI1) (E). Plasmid pACYC184::Tn21(lane 8) was used as positive control for the presence of theintI1 gene.
- Fig. 2.
Integrons found on plasmids carried by S. enterica serotype Typhimurium. (A) Plasmids were separated by agarose gel electrophoresis and were visualized by ethidium bromide staining. Lane 1, S. enterica serotype Typhimurium 202 donor strain; lane 2, Cm-type E. coli exconjugant carrying the IncFI replicon; lane 3, Ak-type E. coli exconjugant carrying the IncL/M replicon. (B) PCR analysis of integron-borne gene cassettes amplified with the 5′CS and 3′CS primers (Table 1). DNA templates were from the S. enterica serotype Typhimurium 202 (lane 1) and from Ak-type and Cm-type exconjugants (lanes 2 and 3, respectively). In-t1, In-t2, and In-t3 integrons are indicated as 1, 2, and 3, respectively, on the left of the figure. Molecular size standards (lane 4; in kilobases) are indicated on the right.
- Fig. 3.
Structural organization of gene cassettes in S. enterica serotype Typhimurium integrons. Integron-borne gene cassettes are represented as open boxes; black boxes are the 59-base elements (not in scale). The positions of an integrase gene (intI1), Pant promoter, a sulfonamides resistance gene (sul-1), and the 5′CS and 3′CS primers are indicated by arrows. Restriction sites for BamHI (B), PvuII (P), and Rsa I (R) are indicated.
Tables
- Table 1.
Primers used for integron detection by PCR
Primer DNA sequence Position in submitted sequence Accession no. 5′CS 5′-GGCATCCAAGCAGCAAG-3′ 1190–1206 M73819 3′CS 5′-AAGCAGACTTGACCTGA-3′ 1342–1326 M73819 intI2A 5′-ATGTCTAACAGTCCATTTTTAAATTCTA-3′ 1914–1886 AJ002782 intI2B 5′-AAATCTTTAACCCGCAAACGC-3′ 1475–1495 AJ002782 intI3A 5′-GTGGCGCAGGGTGTGGAC-3′ 194–211 D50438 intI3B 5′-ACAGACCGAGAAGGCTTATG-3′ 959–938 D50438 - Table 2.
Antibiotic resistance phenotypes of S. enterica serotype Typhimurium donor strains and E. coli exconjugants, transferred plasmids, and type of integrons found on plasmids
Salmonella R type No. of strains Donor strain Exconjugant R type Frequency of transfer Transferred plasmid Integron(s) ApCmKmSmSuTpTeNa 5 366 ApCmKmSmSuTpTe 5 × 10−5 140-kb IncFI In-t1,In-t2 ApCmKmSmSuTpNa 9 341 ApCmKmSmSuTp 7 × 10−5 140-kb IncFI In-t1,In-t2 ApCmKmSmSuTpTe 15 252 ApCmKmSmSuTe 6 × 10−5 140-kb IncFI In-t1,In-t2 ApCmKmSmSuTpTeGmAk 8 202 ApKmSuTeGmAk 1 ×10−6 100-kb IncL/M In-t3 202 ApCmKmSmSuTpTe 7 × 10−5 140-kb IncFI In-t1,In-t2 298 ApKmSuGmAk 7 × 10−7 100-kb IncL/M In-t3 298 ApCmKmSmSuTpTe 5 × 10−5 140-kb IncFI In-t1,In-t2
