TY - JOUR

T1 - Expansion of the IncX plasmid family for improved identification and typing of novel plasmids in drug-resistant Enterobacteriaceae

A1 - Johnson,Timothy J.

A1 - Bielak,Eliza Maria

A1 - Fortini,Daniela

A1 - Hansen,Lars Hestbjerg

A1 - Hasman,Henrik

A1 - Debroy,Chitrita

A1 - Nolan,Lisa K

A1 - Carattoli,Alessandra

AU - Johnson,Timothy J.

AU - Bielak,Eliza Maria

AU - Fortini,Daniela

AU - Hansen,Lars Hestbjerg

AU - Hasman,Henrik

AU - Debroy,Chitrita

AU - Nolan,Lisa K

AU - Carattoli,Alessandra

PB - Academic Press

PY - 2012

Y1 - 2012

N2 - IncX plasmids are narrow host range plasmids of Enterobactericeae that have been isolated for over 50years. They are known to encode type IV fimbriae enabling their own conjugative transfer, and to provide accessory functions to their host bacteria such as resistance towards antimicrobial agents and biofilm formation. Previous plasmid-based replicon typing procedures have indicated that the prevalence of IncX plasmids is low among members of the Enterobacteriaceae. However, examination of a number of IncX-like plasmid sequences and their occurrence in various organisms suggests that IncX plasmid diversity and prevalence is underappreciated. To address these possible shortcomings, we generated additional plasmid sequences of IncX plasmids of interest and compared them to the genomes of all sequenced IncX-like plasmids. These comparisons revealed that IncX plasmids possess a highly syntenic plasmid backbone, but that they are quite divergent with respect to nucleotide and amino acid similarity. Based on phylogenetic comparisons of the sequenced IncX plasmids, the IncX plasmid group has been expanded to include at least four subtypes, IncX1-IncX4. A revised IncX plasmid replicon typing procedure, based upon these sequences and subtypes, was then developed. Use of this revised typing procedure revealed that IncX plasmid occurrence among bacterial populations is much more common than had previously been acknowledged. Thus, this revised procedure can be used to better discern the occurrence of IncX type plasmids among enterobacterial populations.

AB - IncX plasmids are narrow host range plasmids of Enterobactericeae that have been isolated for over 50years. They are known to encode type IV fimbriae enabling their own conjugative transfer, and to provide accessory functions to their host bacteria such as resistance towards antimicrobial agents and biofilm formation. Previous plasmid-based replicon typing procedures have indicated that the prevalence of IncX plasmids is low among members of the Enterobacteriaceae. However, examination of a number of IncX-like plasmid sequences and their occurrence in various organisms suggests that IncX plasmid diversity and prevalence is underappreciated. To address these possible shortcomings, we generated additional plasmid sequences of IncX plasmids of interest and compared them to the genomes of all sequenced IncX-like plasmids. These comparisons revealed that IncX plasmids possess a highly syntenic plasmid backbone, but that they are quite divergent with respect to nucleotide and amino acid similarity. Based on phylogenetic comparisons of the sequenced IncX plasmids, the IncX plasmid group has been expanded to include at least four subtypes, IncX1-IncX4. A revised IncX plasmid replicon typing procedure, based upon these sequences and subtypes, was then developed. Use of this revised typing procedure revealed that IncX plasmid occurrence among bacterial populations is much more common than had previously been acknowledged. Thus, this revised procedure can be used to better discern the occurrence of IncX type plasmids among enterobacterial populations.

KW - IncX

KW - Plasmid

KW - Replicon typing

KW - Genomics

KW - Resistance

U2 - 10.1016/j.plasmid.2012.03.001

DO - 10.1016/j.plasmid.2012.03.001

JO - Plasmid

JF - Plasmid

SN - 0147-619X

IS - 1

VL - 68

SP - 43

EP - 50

ER -