title: Short communication: Prevalence of Staphylococcus aureus and methicillin-resistant S. aureus in bulk tank milk from dairy goat farms in Northern Italy.
abstract: Staphylococcus aureus is regarded as a leading cause of mastitis in goats. However, few data are available on the presence of methicillin-resistant S. aureus (MRSA) in this species. The aim of this study was to assess the prevalence of S. aureus and MRSA in bulk tank milk samples from dairy goat farms in Northern Italy. Eighty-five out of 197 samples (43.1%) tested positive for S. aureus with counts ranging from 10 to more than 1.5 × 10(4) cfu/mL. The MRSA was screened by both direct plating followed by a disk diffusion test to evaluate methicillin resistance and a selective enrichment method. Methicillin-resistance was confirmed by mecA-specific PCR. Methicillin-resistant S. aureus was identified in 4 samples (2.0%) and multilocus sequence typing (MLST) showed the presence of livestock-associated MRSA belonging to lineages ST398 (n = 3) and ST1 (n = 1). In one case we demonstrated that the same MRSA strain was able to persist over time on the farm, being isolated from both bulk tank milk and the udder of 3 goats 1 yr after the first isolation. The high prevalence of S. aureus-positive herds detected in this study and the presence of MRSA strains belonging to livestock-associated genotypes is of concern, and represents a novel finding in the Italian dairy goat production system. The application of stringent measures for the control of S. aureus mastitis at the farm level seems appropriate to reduce the economic losses, and to minimize the risk of foodborne illness and the transmission of MRSA to humans by occupational exposure.
authors: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Lodi 26900, Italy.
authors: C
authors: C
authors: Cortimiglia
authors: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Lodi 26900, Italy.
authors: V
authors: V
authors: Bianchini
authors: Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana, Rome 00178, Italy.
authors: A
authors: A
authors: Franco
authors: Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana, Rome 00178, Italy.
authors: A
authors: A
authors: Caprioli
authors: Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana, Rome 00178, Italy.
authors: A
authors: A
authors: Battisti
authors: Associazione Regionale Allevatori, Crema 26013 (CR), Italy.
authors: L
authors: L
authors: Colombo
authors: Associazione Regionale Allevatori, Crema 26013 (CR), Italy.
authors: K
authors: K
authors: Stradiotto
authors: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Lodi 26900, Italy.
authors: F
authors: F
authors: Vezzoli
authors: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Lodi 26900, Italy. Electronic address: mariovittorio.luini@izsler.it.
authors: M
authors: M
authors: Luini
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics; D005260:Female; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D006041:Goats; D007558:Italy; D008321:Mammary Glands, Animal / Q000382:microbiology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000302:isolation & purification*; D008892:Milk / Q000382:microbiology*; D058885:Multilocus Sequence Typing; D046915:Penicillin-Binding Proteins / Q000032:analysis / Q000235:genetics; D016133:Polymerase Chain Reaction; D013211:Staphylococcus aureus / Q000145:classification / Q000302:isolation & purification*
chemical_list: D001426:Bacterial Proteins; D046915:Penicillin-Binding Proteins; C487789:mecA protein, Staphylococcus aureus
keywords: Staphylococcus aureus; bulk tank milk; dairy goat; methicillin-resistance