VanA-Enterococcus faecalis in Poland: hospital population clonal structure and vanA mobilome

AbstractThe aim of our study was to characterize the epidemiological situation concerning nosocomial vancomycin-resistantEnterococcus faecalis of VanA-phenotype (VREfs-VanA) in Poland by investigating their clonal relationships and thevanA-associated mobilome. One-hundred twenty-five clinical isolates of VREfs-VanA collected between 2004 and 2016 were studied by phenotypic assays, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), PCR detection of plasmid-specific genes, and Tn1546 structure and localization mapping. Selected isolates were subjected to PFGE-S1, Southern hybridization, genomic sequencing and conjugation experiments. The majority of isolates (97.6%) belonged to clonal complexes CC2 and CC87 ofE. faecalis. All isolates were resistant to vancomycin and teicoplanin, and resistance to ciprofloxacin and aminoglycosides (high level) was very prevalent in this group. VanA phenotype was associated with 16 types of Tn1546, carrying insertion sequences IS1216, ISEfa4, IS1251 and IS1542, located onrepUS1pVEF1,rep1pIP501,rep2pRE25,rep9pAD1/pTEF2/pCF10 andrep6pS86 replicons. The most common Tn1546 B- and BB-type transposons, harbouring one or two copies of IS1216, were inserted betweenrep18ap200B andrepUS1pVEF1 genes and located on  ~ 20 kb and 150–200 kb plasmids. VREfs-VanA in Poland represent a polyclonal group, indicating a number of acquisitions of thevanA determinant. TherepUS1pVEF1-vanA plasmids, unique for Poland, were the main facto...
Source: European Journal of Clinical Microbiology and Infectious Diseases - Category: Microbiology Source Type: research