|
|
Letter
Vancomycin-resistant Enterococcus
faecalis in Serbia
Branka Stošović,* Srdjan Stepanović,† Susan Donabedian,‡
Tanja Tošić,* and Milica Jovanović*
*Institute of Infectious and Tropical Diseases “Dr Kosta Todorović,”
Belgrade, Serbia; †University of Belgrade School of Medicine, Belgrade,
Serbia; and ‡William Beaumont Hospital, Royal Oak, Michigan, USA
Suggested citation
for this article:
Stošović B, Stepanović S, Donabedian S, Tošić T, Jovanović
M. Vancomycin-resistant Enterococcus faecalis in Serbia. Emerg
Infect Dis [serial online] 2004 Jan [date cited]. Available from:
URL: http://www.cdc.gov/ncidod/EID/vol10no1/02-0790.htm
To the Editor: First isolated in France (1),
vancomycin-resistant enterococci (VRE) have become pathogens of major
importance, particularly in the United States (2). Infections
due to VRE are still uncommon in most European countries (3).
We report the first isolation of high-level vancomycin-resistant Enterococcus
faecalis in Serbia.
A 55-year-old woman was admitted to the Clinic for Cardiovascular Diseases,
Belgrade, on April 1, 2002, for aortobifemoral bypass surgery. Three weeks
after she was admitted to the hospital, an infection developed in the
surgical wound and treatment with trimethoprim-sulfamethoxazole (160/800
mg q 12 h) was empirically introduced. Bacteriologic analysis of the wound
swab sample showed a methicillin-resistant strain of Staphylococcus
aureus, a multiresistant strain of Acinetobacter sp., a commonly
susceptible strain of Enterococcus sp., and a VRE strain. According
to the results of susceptibility testing, imipenem (1 g q 6 h) was added
to the patient’s treatment protocol. VRE were not isolated from subsequent
wound samples or any other sample submitted for microbiologic analysis.
The patient was discharged at the end of the 14-day treatment period.
The isolate was identified as E. faecalis by biochemical characterization,
as recommended by Facklam and Collins (4) and confirmed
by API 20 Strep (bioMérieux, Marcy-l’Etoile, France). Susceptibility testing,
performed by the disk diffusion method, showed that the isolate was resistant
to vancomycin, teicoplanin, gentamicin, streptomycin, tetracycline, and
ciprofloxacin, while susceptible to ampicillin, amoxicillin, amoxicillin
and clavulanic acid, and imipenem. Resistance to vancomycin, teicoplanin,
gentamicin, and streptomycin was confirmed by the broth dilution method,
according to the National Committee for Clinical Laboratory Standards
(NCCLS) recommendations (5). The obtained MICs were 256
mg/mL for vancomycin, 64 mg/mL for teicoplanin, >4,000 mg/mL for gentamicin,
and >2,000 mg/mL for streptomycin. This phenotype, with high-level
resistance to vancomycin and teicoplanin, is typical for the vanA
genotype (2). The strain was subsequently genotyped by
pulsed-field gel electrophoresis, using previously described methods (6).
The presence of the vanA gene was confirmed by polymerase chain
reaction assay, according to a previously described procedure (7).
E. faecium EF228 was used as the positive control.
The enterococci are among the most frequent causes of nosocomial infections,
particularly in intensive care units, and present a major therapeutic
challenge (2). While the emergence of VRE strains in
the United States is probably associated with extensive use of vancomycin,
the occurrence of VRE in Europe is possibly due to application of avoparcin
(glycopeptide analog) as a growth promoter in animal husbandry (3).
However, avoparcin has not been used in Serbia, and vancomycin application
has been restricted to hospitalized patients and quite limited due to
its high cost. Thus, emergence of VRE strains in Serbia has not been likely.
The origin of this VRE isolate is unknown: the strain may have been imported
or may have originated from the hospital environment. The first prospective
pan-European VRE surveillance study (January–April 1997) showed VanA-VRE
strains in only eight European countries, with isolates numbering from
one to four per country (3). No epidemiologic relations
were established among the VanA isolates, and only 2 out of 18 isolates
(11%) were identified as E. faecalis (3). Since
our patient-case had no history of travel outside Serbia, we assumed that
the VRE isolate originated from the hospital environment. However, a study
investigating the occurrence of VRE strains in Belgrade, the capital of
Serbia, detected no such isolates in five different hospitals (8).
Although the study did not analyze samples from the Clinic for Cardiovascular
Diseases, it did include samples from the Clinic for General Surgery,
which is located within the same building. The susceptibility of 191 isolates
of enterococci to vancomycin was tested by agar dilution method according
to NCCLS recommendations. Of the 191 isolates, 159 were classified as
susceptible and 32 as intermediately susceptible.
This report of the first isolation of VRE in Serbia, as well as the previously
shown presence of enterococci displaying intermediary susceptibility to
vancomycin, provides the rationale for future active screening for VRE
in hospital environments in the region.
References
- Leclercq R, Derlot E, Duval J, Courvalin P. Plasmid-mediated
resistance to vancomycin and teicoplanin in Enterococcus faecium.
N Engl J Med 1988;319:157–61.
- Cetinkaya Y, Falk P, Mayhall CG. Vancomycin-resistant
enterococci. Clin Microbiol Rev 2000;13:686–707.
- Schouten MA, Hoogkamp-Korstanje JA, Meis JF, Voss A. Prevalence
of vancomycin-resistant enterococci in Europe. Eur J Clin Microbiol
Infect Dis 2000;19:816–22.
- Facklam RR, Collins MD. Identification
of Enterococcus species isolated from human infections by a conventional
test scheme. J Clin Microbiol 1989;27:731–4.
- National Committee for Clinical Laboratory Standards. Methods for
dilution antimicrobial susceptibility tests for bacteria that grow aerobically.
Approved standard M7-A4. Wayne (PA): National Committee for Clinical
Laboratory Standards; 1997.
- Donabedian S, Chow JW, Shlaes DM, Green M, Zervos MJ. DNA
hybridization and contour-clamped homogeneous electric field electrophoresis
for identification of enterococci to the species level. J Clin Microbiol
1995;33:141–5.
- Clark NC, Cooksey RC, Hill BC, Swenson JM, Tenover FC. Characterization
of glycopeptide-resistant enterococci from U.S. hospitals. Antimicrob
Agents Chemother 1993;37:2311–7.
- Dakić I, Vuković D, Stepanović S, Kalezić I, Švabić-Vlahović
M. Enterococci isolated in Belgrade hospitals: the resistance to vancomycin.
In: Abstract book of the 9th International Congress on Infectious Diseases,
Buenos Aires, Argentina, 2000 April 10–13; p. 213.
|
