Plasmids and pathogenicity

IncHI plasmids, a dynamic link between resistance and pathogenicity.

Plasmids of incompatibility group (Inc) HI1 are important vectors of antibiotic resistance in both of the major causal agents of enteric fever: Salmonella enterica subspecies enterica serovar Typhi and S. Paratyphi A. In S. Typhi, IncHI1 plasmids appeared in the 1970s and spread globally. In some circumstances they are maintained within the bacterial population even in the absence of selection ...

Comparative Genomics of Rhodococcus equi Virulence Plasmids Indicates Host-Driven Evolution of the vap Pathogenicity Island

The conjugative virulence plasmid is a key component of the Rhodococcus equi accessory genome essential for pathogenesis. Three host-associated virulence plasmid types have been identified the equine pVAPA and porcine pVAPB circular variants, and the linear pVAPN found in bovine (ruminant) isolates. We recently characterized the R. equi pangenome (Anastasi E, et al. 2016. Pangenome and phylogen...

Mitochondrial DNA Mutations, Pathogenicity and Inheritance

Mitochondria contain their own DNA (mtDNA), which codes for 13 proteins (all subunits of the respiratory chain complexes), 22 tRNAs and 2 rRNAs. Several mtDNA point mutations as well as deletions have been shown to be causative in well-defined mitochondrial disorders. A mixture of mutated and wild type mtDNA (heteroplasmy) is found in most of these disorders. Inheritance of mtDNA is maternal, a...

Plasmids and Putative Virulence Characters in Proteus mirabilis

Evolution of the Rhodococcus equi vap pathogenicity island seen through comparison of host-associated vapA and vapB virulence plasmids.

The pathogenic actinomycete Rhodococcus equi harbors different types of virulence plasmids associated with specific nonhuman hosts. We determined the complete DNA sequence of a vapB(+) plasmid, typically associated with pig isolates, and compared it with that of the horse-specific vapA(+) plasmid type. pVAPB1593, a circular 79,251-bp element, had the same housekeeping backbone as the vapA(+) pl...