Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Curr Microbiol. 2008 Nov;57(5):442-8. doi: 10.1007/s00284-008-9227-4. Epub 2008 Sep 4.

Clonality and occurrence of genes encoding antibiotic resistance and biofilm in methicillin-resistant Staphylococcus epidermidis strains isolated from catheters and bacteremia in neutropenic patients.

Author information

  • 1Laboratory of the National Bone Marrow Transplantation Centre, Street Djebel-Lakdhar, Bab-Saadoun, 1006, Tunis, Tunisia.

Abstract

Thirty methicillin-resistant Staphylococcus epidermidis strains isolated from catheters and blood cultures from neutropenic patients were studied. They were classified into 17 multidrug-resistance patterns. Polymerase cahin reaction analysis revealed that methicillin resistance was encoded by the mecA gene in all strains, and aminoglycosides resistance was due to aac(6')-Ie-aph(2'')-Ia (23 strains), ant(4')-Ia (13), and aph(3')-IIIa (1) genes. The aac(6')-Ie-aph(2'')-Ia gene was detected concomitantly with aph(3')-IIIa, and ant(4')-Ia genes in one and nine strains, respectively. Erythromycin resistance was encoded by the ermC (11 strains), ermA (6), and msrA (2) genes. The ermC gene was inducibly expressed in five strains, whereas the ermA was exclusively constitutively expressed. The icaA and icaC genes were detected in 19 strains; however, biofilm production was observed in only 16 strains. Most strains harbored multiple plasmids of variable sizes ranging from 2.2 to 70 kb, and two strains were plasmid-free. PFGE identified 15 distinct PFGE types, and five predominant genotypes were found. Our study showed the occurrence of complex genetic phenomenons. In unrelated strains, evidence of horizontal transfer of antibiotic-encoding genes and/or ica operon, and in indistinguishable strains, there is a quite good likelihood of independent steps of loss and/or gain of these genes. This genome dynamicity might have enhanced the invasiveness power of these methicillin-resistant S epidermidis strains.

PMID:
18769853
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for Springer
    Loading ...
    Write to the Help Desk