vanB2-Tn5382 typing in enterococcal clones disseminated around 16 hospitals in Chile

Abstract number: P2115

López M., Saavedra G., Rodriguez-Baños M., Hormazábal J.C., Maldonado A., Silva J., Torres C., del Campo R.

Objectives: To analyse the composition of the genetic element Tn5382 associated with the vanB2 genotype in selected enterococcal clones disseminated around 16 different Hospitals in Chile, as well as the presence of other resistance, virulence and bacteriocin genes.

Methods: Seven unrelated PFGE-SmaI clones (2 E. faecalis and 5 E. faecium) corresponding to 10 E. faecalis and 60 E. faecium vanB2 isolates were studied. Strains were collected at the National Reference Institute in Santiago (ISPCH) from 16 different hospitals of four regions of Chile. Antimicrobial susceptibility was determined by the agar dilution method. Presence of ISEnfa110 or ISEnfa200, as well as the vanX-ORFC fragment or the antimicrobial resistance genes erm(B), tet(M), tet(L), aph(3')-III and aac(6')-aph(2") were tested by PCR. Similarly, esp, hyl, gelE, fsrA, fsrB, fsrC, cylLLS, cylA, cylB, cylM, and agg virulent factors were tested in all vanB2-enterococcal clones by PCR. Amino acid changes in PBP5 protein was studied in one penicillin-resistant E. faecium clone by PCR and sequencing. The purK allele was analysed by PCR and sequencing. Bacteriocin production was analysed using 8 indicator bacteria and bacteriocin structural genes were checked by PCR.

Results: All five vanB2 E. faecium clones harboured the Tn5382 element with positive amplifications for ISEnfa110 upstream of the vanRB gene, whereas ISEnfa200 was not detected between the intergenic region vanSB-vanYB. Negative results were obtained for both ISEnfa100/200 elements in the two vanB2-E. faecalis clones. The sequence of vanX-ORFC fragment corresponded to the described sequence 203412. Eight amino acid changes were detected in PBP5 protein in one ampicillin-resistant E. faecium clones respect to the reference one. Almost all enterococcal clones tested harboured the resistant genes erm(B), tet(M), aph(3'), and aac(6')-aph(2"), and the E. faecalis ones also contained all the virulence tested factors. The purK1 allele was found in all E. faecium clones. Bacteriocin production was detected in two E. faecium and two E. faecalis clones, showing activity against L. monocytogenes, among others, and they harboured the entA gene.

Conclusions: different vanB2 clones of E. faecium and E. faecalis have been disseminated in hospitals of four different regions of Chile and most of them harbour a wide variety of antibiotic resistance genes and virulence genes.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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