Investigation published in PLoS ONE

August 31^st, 2015

Methicillin-resistant Staphylococcus aureus (MRSA) Sequence Type (ST)1, Clonal Complex(CC)1, SCCmec V is one of the major Livestock-Associated (LA-) lineages in pig farming industry in Italy and is associated with pigs in other European countries. Recently, it has been increasingly detected in Italian dairy cattle herds. The aim of this study was to analyse the differences between ST1 MRSA and methicillin-susceptible S. aureus (MSSA) from cattle and pig herds in Italy and Europe and human isolates. Sixty-tree animal isolates from different holdings and 20 human isolates were characterized by pulsed-field gel electrophoresis (PFGE), spa-typing, SCCmec typing, and by micro-array analysis for several virulence, antimicrobial resistance, and strain/host-specific marker genes. Three major PFGE clusters were detected. The bovine isolates shared a high (≥90% to 100%) similarity with human isolates and carried the same SCCmec type IVa. They often showed genetic features typical of human adaptation or present in human-associated CC1: Immune evasion cluster (IEC) genes sak and scn, or sea; sat and aphA3-mediated aminoglycoside resistance. Contrary, typical markers of porcine origin in Italy and Spain, like erm(A) mediated macrolide-lincosamide-streptograminB, and of vga(A)-mediated pleuromutilin resistance were always absent in human and bovine isolates. Most of ST(CC)1 MRSA from dairy cattle were multidrug-resistant and contained virulence and immunomodulatory genes associated with full capability of colonizing humans. As such, these strains may represent a greater human hazard than the porcine strains. The zoonotic capacity of CC1 LA-MRSA from livestock must be taken seriously and measures should be implemented at farm-level to prevent spill-over

Alba P., Feltrin F., Cordaro G., Porrero MC., Kraushaar B., Arqudin MA., Nykasenoja S., Monaco M., Stegger M., Aarestrup FM., Butaye P., Franco A. and Battisti A.

Livestock-Associated Methicillin Resistant and Methicillin Susceptible Staphylococcus aureus Sequence Type (CC)1 in European Farmed Animals: High Genetic Relatedness of Isolates from Italian Cattle Herds and Humans

Livestock-Associated Methicillin Resistant and Methicillin Susceptible Staphylococcus aureus Sequence Type (CC)1 in European Farmed Animals: High Genetic Relatedness of Isolates from Italian Cattle Herds and Humans

	Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana (IZSLT).
	Servicio de Zoonosis de Transmisión Alimentaria y Resistencia a Antimicrobianos (ZTA). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM).
	Federal Institute for Risk Assessment (BfR).
	Veterinary and Agrochemical Research Centre (CODA_CERVA).
	Finnish Food Safety Authority (EVIRA).
	Istituto Superiore di Sanità.
	Department of Microbiological Surveillance and Research. Statens Serum Institut (SSI).
	National Food Institute (DTU Food). Technical University of Denmark (DTU).
	Department of Biosciences. School of Veterinary Medicine. Ross University.
	Department of Pathology, Bacteriology, and Poultry Diseases. Faculty of Veterinary Medicine. University of Ghent (UGENT).
	Department of Microbiology. Université Libre de Bruxelles (ULB).
	Hôpital Erasme Laboratoire de Référence MRSA.