Vancomycin-resistant enterococci still persist in slaughtered poultry in Hungary 8 years after the ban on avoparcin

Abstract number: 1733_189

Ghidan A., Dobay O., Kaszanyitzky E., Samu P., Amyes S., Nagy K., Rozgonyi F.

Objectives: Vancomycin-resistant enterococci (VRE) are one of the major problems in the field of antibiotic resistance. Fortunately, the proportion of human VRE isolates remains very low in Hungary; however, VREs persist in animal samples. In this report we examined the glycopeptide susceptibility of enterococci, isolated in 2005, from slaughtered animals, within the confines of Hungarian Antibiotic Resistance Monitoring System. We determined the presence of the van genes and their genetic relatedness in enterococci from poultry.

Methods:Enterococcus sp. (n = 175) were collected from intestinal samples of slaughtered poultry in 2005. The origin of the samples was registered at county level. After screening the strains with 30 microgram vancomycin disc 19 (86%) intermediate resistant and 4 (3%) resistant strains were found. The MICs of vancomycin and teicoplanin were determined by agar dilution. The presence of the van genes was detected by PCR. The identity of the van gene carrying strains was identified by PCR using genus-specific and species-specific primers. The potential similarities of these strains was determined by PFGE (digesting with SmaI).

Results: The distribution of MICs among 23 enterococcus strains which were intermediate or resistant to vancomycin were 0.25 mg/L (4.4%), 2 mg/L (8.6%), 4 mg/L (8.6%), 8 mg/L (61%), 16 mg/L (8.6%) and 256 mg/L (8.6%). The MICs of teicoplanin were 0.25 mg/L (4.3%), 1 mg/L (8.6%), 4 mg/L (78.3%), 16 mg/L (4.3%), and 256 mg/L (4.3%). The two most vancomycin-resistant strains were vanA carriers (1 E. faecalis and 1 E. faecium). No strains carried vanB, vanC1 or vanC2. The E. faecalis strain had high resistance to both glycopeptides (MICs = 256 mg/L) and the E. faecium had high resistance to vancomycin (MIC = 256 mg/L) and intermediate resistance to teicoplanin (MIC = 16 mg/L). These strains originated from two different counties of Hungary. These 23 strains were not closely related to one another.

Conclusion: Avoparcin was used as a growth promoter for broiler chickens since 1989 but was banned in 1998. Despite this prohibition, the VRE strains only disappeared in 2003. However, in 2004 strains only with higher MICs to vancomycin were detected and, in 2005, two strains were vanA positive. The farms that produced these strains can be reservoirs of VRE and the affected farms should change the technology of disinfection and breeding in order to prevent the emergence of high numbers of human VRE isolates in Hungary.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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