Molecular Characterization of a Multidrug Resistance IncF Plasmid from the Globally Disseminated Escherichia coli ST131 Clone

Abstract

Escherichia coli sequence type 131 (E. coli ST131) is a recently emerged and globally disseminated multidrug resistant clone associated with urinary tract and bloodstream infections. Plasmids represent a major vehicle for the carriage of antibiotic resistance genes in E. coli ST131. In this study, we determined the complete sequence and performed a comprehensive annotation of pEC958, an IncF plasmid from the E. coli ST131 reference strain EC958. Plasmid pEC958 is 135.6 kb in size, harbours two replicons (RepFIA and RepFII) and contains 12 antibiotic resistance genes (including the bla CTX-M-15 gene). We also carried out hyper-saturated transposon mutagenesis and multiplexed transposon directed insertion-site sequencing (TraDIS) to investigate the biology of pEC958. TraDIS data showed that while only the RepFII replicon was required for pEC958 replication, the RepFIA replicon contains genes essential for its partitioning. Thus, our data provides direct evidence that the RepFIA and RepFII replicons in pEC958 cooperate to ensure their stable inheritance. The gene encoding the antitoxin component (ccdA) of the post-segregational killing system CcdAB was also protected from mutagenesis, demonstrating this system is active. Sequence comparison with a global collection of ST131 strains suggest that IncF represents the most common type of plasmid in this clone, and underscores the need to understand its evolution and contribution to the spread of antibiotic resistance genes in E. coli ST131.

Horizontal Dissemination of Antimicrobial Resistance Determinants in Multiple Salmonella Serotypes following Isolation from the Commercial Swine Operation Environment after Manure Application

“…Our result supports the view that the IncF (both FI and FII) family was well adapted and commonly distributed in E. coli and Salmonella (14, 15, 34, 46). Wang et al (14) reported that IncFIIA was detected only in S. enterica serotype Typhimurium, which correlates with our findings; however, we also detected the FIIA type in the S. enterica serotype 4,12:i:Ϫ. IncF family plasmids have been reported to contribute to the spread of AMR in Enterobacteriaceae and have been associated with specific genes conferring resistance to aminoglycosides, ␤-lactams, and quinolones (43,46,47).…”

Comparative Genome Analysis of Extended-Spectrum-β-Lactamase-Producing Escherichia coli Sequence Type 131 Strains from Nepal and Japan

“…We previously found that a plasmid resembling pEC958 and harboring FIA and FII (16) was present in approximately 80% of the ESBL- E. coli ST131 isolates from Nepal (5). The high prevalence of IncF (IncFIA, FIB, and FII) observed among ESBL- E. coli ST131 isolates from Nepal is consistent with these previous reports and is reasonable considering the high prevalence of H 30Rx among ESBL- E. coli ST131 isolates.…”

Comprehensive analysis of type 1 fimbriae regulation in fimB‐null strains from the multidrug resistant Escherichia coli ST131 clone

“…The LysR family transcriptional regulator lrhA has previously been shown to repress both fimB and fimE (Blumer et al ., ), and our identification of lrhA in this study as a repressor of fimE is consistent with these results. The yubO gene is located on a 135.6 kb IncF plasmid in EC958 and encodes a protein of unknown function (Phan et al ., ). Three independent Tn 5 mutants were identified in yubO , however specific mutagenesis of yubO failed to reproduce a significant increase in fimE transcription (data not shown).…”