Random Amplified Polymorphic DNA Typing of Enterococcus. faecalis Isolated from Lebanese Individuals

Year 2000, Volume: 5 Issue: 1, 18 - 20, 20.02.2013

H.s. Harakeh M. Uvadah G.m. Matar

Abstract

Objective: In this study we assessed the utility of ran-dom amplified polymorphic DNA in the subtyping of
38 isolates of Enterococcus faecalis.
Method: Twenty of 38 subtypes were recovered from
urinary tract infections and 18 from rectal swabs of
hospitalized patients with no enterococcal infections.
All isolates were initially identified by conventional bac-teriological methods and the API 20 Streptococcus sys-tem.  Biotyping was done on the basis of hippurate hy-drolysis (HH) test using API 20S. Susceptibility of the
isolates to vancomycin, teicoplanin, ampicillin and gen-tamicin was performed by the disk diffusion and the
agar dilution methods. Antimicrobials were selected
based on treatment regimen adopted by clinicians. DNA
was extracted from all isolates using the PureGene kit
and Random Amplified Polymorphic DNA Typing (RAPD)
was done using a 10 mer and 22 mer primers reflecting
the GC content of the genome.
Results: Our data have shown that 38 tested isolates
were E. faecalis. Thirteen of 38 were of fecal origin and
6/38 were of urine origin. All 19 isolates were of bio-type I (HH positive). The remaining 5 of fecal origin
and 14 of urine origin were of biotype II (HH negative).
All isolates were susceptible to vancomycin,
teicoplanin and ampicillin except 3 urine and 1 fecal
isolates that showed resistance to ampicillin. All urine
isolates were resistant to gentamicin while 3 of 18 fe-cal isolates were susceptible to this antimicrobial
agent. RAPD data have shown that 2/19 biotype I iso-lates, showed one RAPD pattern and were susceptible
to teichoplanin and vancomycin; and 2/19 showed a
different pattern and were susceptible to all tested
antimicrobials except gentamicin. All 4  isolates were
of urine origin. The remaining 15 biotype I isolates had
different patterns. In addition, of 19 biotype II isolates,
2 showed one pattern and the remaining 17 different
patterns. Two isolates were of urine origin and resis-tant to gentamicin. The RAPD patterns were reproduc-ible.
Conclusion:  These observations suggest that RAPD
is efficient for subtyping E. faecalis and may be useful
as a tool in epidemiologic investigations.
Key words: RAPD, enterococcus faecalis, subtyping.

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