Prevalence of Staphylococcus aureus and of methicillin-resistant S. aureus clonal complexes in bulk tank milk from dairy cattle herds in Lombardy Region (Northern Italy)

Abstract

Staphylococcus aureus is the most important causative agent of subclinical mastitis in cattle resulting in reduced milk production and quality. Methicillin-resistant S. aureus (MRSA) strains has a clear zoonotic relevance, especially in the case of occupational exposure. The aim of the study was to evaluate the prevalence of S. aureus and MRSA in bulk tank milk (BTM) from dairy cattle herds in the Lombardy Region (Northern Italy) and to identify the main MRSA circulating genotypes. MRSA strains were characterized by susceptibility testing, multi-locus sequence typing (MLST), spa typing and SCCmec typing. A total 844 BTM samples were analysed and S. aureus and MRSA were detected in 47·2% and 3·8% of dairy herds, respectively. MLST showed that the majority (28/32) of isolates belonged to the typical livestock-associated lineages: ST398, ST97 and ST1. Interestingly, in this study we report for the first time the new ST3211, a single locus variant of ST(CC)22, with the newly described 462 aroE allele. Our study indicates high diffusion of S. aureus mastitis and low, but not negligible, prevalence of MRSA in the considered area, suggesting the need for planning specific control programmes for bovine mastitis caused by S. aureus, especially when MRSA is implicated.

The Prevalence and Antibiotic Resistance of Methicillin-Resistant Staphylococcus aureus (MRSA) in Milk and Dairy Products in Balikesir, Turkey

“…Daka et al (2012) (Daka et al, 2012) and higher from other (Vyletelova et al, 2011, Paterson et al, 2012, Kanaan and Al-Shammary 2013, Riva et al, 2015, Cortimiglia et al, 2016. The reports on the prevalence of MRSA in milk and dairy products vary significantly between different studies and different countries or even among regions within the same country where they carried out and even among herds within the same region.…”

Molecular Characteristics of Staphylococcus aureus Causing Bovine Mastitis between 2014 and 2015

“…In European countries and in North America, CC398 was the overwhelmingly dominant LA MRSA, whereas CC9 predominated in most Asian countries (Cortimiglia et al, 2016; Sharma et al, 2016). In our study, all CC398 strains were identified as MSSA strains.…”

Prevalence and Characterization of Staphylococcus aureus Isolated from Bulk Tank Milk Dairy Cow Farms in West Bank-Palestine

“…MRSA has increasingly been recognized in farm animal populations in recent years and has been considered as an important pathogen in animals. The prevalence of S. aureus as well as MRSA in bovine milk has been reported from several countries such as USA, Denmark [1,8], Turkey [9], Brazil [10], Germany [11], India [12], Iran [13,14], Great Britain [15], Italy [16], and Ethiopia [17]. Antibiotic sensitivity to MRSA and/or MSSA strains isolated from bovine milk has been studied previously [8,9,10,12,15,16,18,19].…”

“…The prevalence of S. aureus as well as MRSA in bovine milk has been reported from several countries such as USA, Denmark [1,8], Turkey [9], Brazil [10], Germany [11], India [12], Iran [13,14], Great Britain [15], Italy [16], and Ethiopia [17]. Antibiotic sensitivity to MRSA and/or MSSA strains isolated from bovine milk has been studied previously [8,9,10,12,15,16,18,19]. In addition, the heterogeneity among MSSA and/or MRSA strains isolated from milk samples has been studied by different methods [1,9,10,11,15,16,18].…”

“…Antibiotic sensitivity to MRSA and/or MSSA strains isolated from bovine milk has been studied previously [8,9,10,12,15,16,18,19]. In addition, the heterogeneity among MSSA and/or MRSA strains isolated from milk samples has been studied by different methods [1,9,10,11,15,16,18].…”