Isolation and characterization of multidrug-resistant bacteria from minced meat in Austria.

INTRODUCTION Resistant bacteria are a well-known public health problem. This study was conducted to investigate the prevalence and genetic characteristics of extended spectrum β-lactamase (ESBL) producing enterobacteria, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE) in mixed minced meat from pork and beef. METHODS One hundred samples of mixed minced meat were collected from supermarkets (n = 70) and local butcher shops (n = 30) in the city of Graz (Austria). After enrichment and inoculation on selective media, bacteria were identified with MALDI-TOF MS or Vitek2 systems, tested for antibiotic resistance and further characterized with PCR and sequencing. RESULTS In 20 of the 100 meat samples 24 ESBL positive Escherichia coli isolates were found. The most common ESBL among the isolates was CTX-M-1. Other detected bla genes contained CTX-M-14, CTX-M-32, SHV-12 and TEM-52 types. Nine samples were tested positive for MRSA and spa-typed. Detected spa-types were hospital-acquired t3928, as well as livestock-associated t011, t034 and t2241. No VRE were found. CONCLUSION A contamination of meat with ESBL-producing E. coli and MRSA was confirmed in this study. The large diversity of ESBL producing E. coli could indicate a growing dissemination of ESBL genes in E. coli found in meat products from porcine and bovine origin.