Biologia, Bratislava 55/3: 305-310, 2000.
ISSN 0006-3088 (Biologia). ISSN 1335-6399 (Biologia. Section Cellular and Molecular Biology).
Occurrence, origin and spreading of vancomycin-resistant enterococci in hematological patients.
Milan Kolar1*, Iva Vagnerova1, Jan Bardon2 & Ivana Matouskova3
1 Department of Microbiology, Medical Faculty, Palacký University, Olomouc, Hnevotinska 3, CZ-77515 Olomouc, Czech Republic; fax: ++420 68 5632966; e-mail: firstname.lastname@example.org
2 National Veterinary Institute, Olomouc, Jakoubka ze Stribra 2, CZ-77900 Olomouc, Czech Republic
3 Department of Preventive Medicine, Medical Faculty, Palacký University, Olomouc, Hnevotinska 3, CZ-77515 Olomouc, Czech Republic
The investigation was focused on the occurrence and origin of vancomycin-resistant enterococci (VRE) at the Hemato-oncologic Department of the University Hospital in Olomouc (Czech Republic) and their subsequent spread. Simultaneously, VRE isolated at the National Veterinary Institute in Olomouc were characterized and their occurrence in animals was evaluated. Occurrence of VRE in the University Hospital in Olomouc was described for the first time in 1997. At that time, a total of 628 strains of the genus Enterococcus were isolated from the samples of patients hospitalised in the Hemato-oncologic Department. Seven strains (1.1%) were found to be resistant to vancomycin. Five of them were identified as Enterococcus faecalis (of phenotype VanA, VanB) and two strains as Enterococcus faecium VanA. In 1998 727 strains were isolated in this department and 27 (3.7%) of them were resistant to vancomycin. The increase in the number of VRE is statistically significant (p=0.05). Most of them (20 strains, 74.1%) were identified as Enterococcus faecium VanA and 6 strains (22.2%) as Enterococcus faecalis, four of them as phenotype VanA and two ones as phenotype VanB. One strain was identified as Enterococcus mundtii of phenotype VanA. In Enterococcus faecium strains only VanA phenotype was found, while both phenotypes (VanA,VanB) were described in Enterococcus faecalis strains. The stool was documented as the most frequent material with positive occurrence of VRE (61.8%). From the stools and hands of medical staff 22 enterococci strains (resp. 3 strains) were obtained, however no strain was resistant to vancomycin. The administration of vancomycin and teicoplanin at the Hemato-oncologic Department varied from 77.4% to 88.9% of the total consumption of these drugs at the University Hospital. In case of 3rd generation cephalosporins their utilization varied from 42.6% to 48.0% and in fluoroquinolones from 6.5% to 28.6%. Among enterococci from the National Veterinary Institute in Olomouc 4 VRE strains from hens were isolated. VRE were diagnosed mostly as Enterococcus faecium phenotype VanA (75.0%) and 1 strain as Enterococcus sp. group III. phenotype VanB. On the basis of this analysis it is possible to presume the spreading of VRE in hematological patients in relation with the selection pressure of glycopeptides, 3rd generation cephalosporins and also fluoroquinolones. It might be supposed that VRE from animals play a role in human colonization and serve as a source of VanA resistance genes transferable by transposon Tn1546.
Key words: enterococci, resistance, vancomycin, spreading, origin.