gms | German Medical Science

GMS Hygiene and Infection Control

Deutsche Gesellschaft für Krankenhaushygiene (DGKH)

ISSN 2196-5226

Epidemiological alteration in pathogens found in ground meat in Iran: unexpected predominance of vancomycin-resistant Enterococcus faecalis

Unerwartetes Vorkommen von Vancomycin-resistenten Enterococcus faecalis anstelle von Escherichia coli O157H7 in Hackfleisch im Iran

Research Article

  • Nourkhoda Sadeghifard - Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
  • Hossein Kazemian - Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
  • Reza Mohebi - Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
  • corresponding author Zamberi Sekawi - Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
  • Afra Khosravi - Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
  • Nasrin Valizadeh - Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
  • corresponding author Sobhan Ghafourian - Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran

GMS Hyg Infect Control 2015;10:Doc12

doi: 10.3205/dgkh000255, urn:nbn:de:0183-dgkh0002551

Published: July 14, 2015

© 2015 Sadeghifard et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at


Colonization of the human and animal intestinal tract with potential pathogenic bacteria is correlated with the risk of contamination of food products. The current study analyzed the prevalence of Enterococcus faecalis and Escherichia coli O157H7 in ground meat in Ilam, Iran.

Both index organisms were identified following standard food microbiological methods. For E. faecalis, the susceptibility to vancomycin was tested, and PCR was used to check for the vanA gene.

E. faecalis was present in all 24 ground meat samples, with no E. coli O157H7 detected in samples. The analysis showed the presence of the vanA gene in 5/24 vancomycin resistant enterococci.

In conclusion, this study for the first time demonstrates the presence of vancomycin-resistant enterococci in ground meat in Iran. This observation warrants further epidemiologic investigation and should be followed up in the future.

Keywords: Enterococcus faecalis, VRE, Escherichia coli O157H7, ground meat, food, Iran


Das Vorkommen potentiell pathogener Bakterien im menschlichen und tierischen Darmtrakt ist mit einem Kontaminationsrisiko für Lebensmittel verbunden. Daher wurde die Prävalenz von E. faecalis und Escherichia coli O157H7 in Hackfleisch in Ilam, Iran, untersucht.

Nach der Probennahme wurden die Bakterien gemäß lebensmittelhygienischer Methode untersucht. Für E. faecalis wurde ihre Sensitivität gegenüber Vancomycin geprüft und das Vorkommen des vanA-Gens mittels PCR untersucht.

In allen 24 Hackfleischproben war E. faecalis, jedoch in keinem Fall E. coli O157H7 nachweisbar. In 5 der 24 untersuchten Lebensmittelproben wurde VRE-Stämme mit Nachweis des vanA-Gens nachgewiesen. Diese Studie zeigt erstmals das Vorkommen von VRE in Hackfleisch im Iran. In Anbetracht des Vorkommens von VRE sollten weitere epidemiologische Untersuchungen durchgeführt und die Entwicklung genau beobachtet werden.

Schlüsselwörter: Enterococcus faecalis, VRE, Escherichia coli O157H7, Hackfleisch, Lebensmittel, Iran


Negligence of safe food handling, particularly beef and lamb, among the majority of the Iranian population causes high frequencies of chronic disease, including food-related diarrhea [1]. Meat contaminated with Escherichia coli O157H7 ranks among the most severe food-related diarrheal diseases [2]. However, a less pathogenic, but epidemiologically relevant intestinal pathogen is Enterococcus faecalis, which lives commensally in both human and animal intestinal tracts. If food is handled inappropriately, contamination of food products may be the consequence [3]. During the past few years, food products contaminated with vancomycin-resistant enterococci (VRE) have been reported worldwide, and are responsible for morbidity and mortality among hospitalized patients or those receiving systemic antibiotic treatment [3]. To date, no study exists on the prevalence of E.coli O157H7 and E. faecalis in meat in Iran. Therefore, a pilot study was conducted to analyze the prevalence of both index organisms in ground meat.


To investigate the presence or absence of E. coli O157H7 and/or E. faecalis in meat, 24 samples of ground, not cooked meat were collected in 14 “kebab” restaurants in Ilam, Iran. Additionally, 10 samples of raw meat were obtained and screened. Index organisms were identified by conventional microbiological methods and biochemical tests. If E. faecalis was found, minimal inhibitory concentration to vancomycin was determined following CLSI recommendations. Additionally, a vanA-specific PCR was performed to verify vancomycin-resistant enterococci (VRE) strains.


While a few previously conducted studies [4], [5] reported on the presence of E. coli O157H7 without detecting VRE, the present investigation found the opposite result. Although we observed no E. coli O157H7 strains among 24 ground meat samples, E. faecalis was obtained from all 24 samples of ground, cooked kebab meat and 10 raw meat samples. Furthermore, all E. faecalis isolates showed resistance to vancomycin, with 5 strains also showing the presence of the vanA gene in the plasmid [6] of E. faecalis isolates (Figure 1 [Fig. 1]). This is the first report of VRE presence in ground meat in Iran.


To date, most studies have considered E. coli O157H7 as the most important pathogenic microorganism in ground meat in Iran [1], [2]. Surprisingly, none of the ground meat samples investigated in this study was contaminated by E. coli O157H7, whereas E. faecalis, including VRE, was found in ground meat in Iran. This study is the first study reporting on E. faecalis, and particularly VRE, in ground meat in Iran.

Because E. faecalis is a constituent of the gut microflora in animals and humans [3] with a close association between humans and farm animals, enterococci were identified as contaminants in meat [3], [7]. The occurrence of 5 positive vanA genes in E. faecalis isolates are of particular interest, since VRE is associated with nosocomial infections. Although kebab in Iran is well cooked, the presence of E. faecalis and VRE in our tested ground meat is of epidemiological interest.


Our observation warrants further epidemiologic investigation and should be studied in greater depth in the future. Furthermore, restaurants should be monitored more closely to control critical bacteria in animal products, especially in ground meat.


Competing interests

The authors declare that they have no competing interests.


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