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Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) have emerged worldwide as zoonotic pathogens. Data on LA-MRSA in veal calf production in Italy are lacking; the aim of this survey was to fill current knowledge gaps in its prevalence and characteristics. Between February 2012 and January 2013 nasal swabs were taken from 1650 three- to six-month-old veal calves on 55 farms in Piedmont (northwest Italy), including gathering-related epidemiological data. S. aureus were screened for methicillin resistance by phenotypic and molecular ( mecA gene detection) methods. MRSA were further genotyped by multilocus sequence typing. About 30% of the herds tested positive for MRSA: three different clonal complexes (CC398, CC97, and CC1) and staphylococcal cassette chromosome mec types (IVa, IVb, and V) were detected. Multilevel logistic regression model indicated poor cleaning, importation from Austria, and animal age as risk factors and coagulase-negative staphylococci colonization as a predictive factor for the occurrence of MRSA. The detection of CCs circulating in pigs and dairy cattle in Italy underscores the ability of the LA-MRSA clones to spread among animal production systems. In addition to maintaining preventive control measures for human health, better cleaning procedures need to be implemented, especially after new calves have been introduced into the herd.

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) clones other than Clonal Complex (CC)398, as CC1, have been isolated in pigs in some countries, and appeared to be prevalent in Italy. The aim of this study was to evaluate the capability of Sequence Type (ST)1, CC1, LA-MRSA clone to colonize and to be transmitted among piglets. Eighteen caesarean-derived/colostrum-deprived piglets of 35 days of age were assigned randomly to three groups: four seeder piglets were contaminated with a spa type t127, ST1, SCCmec V, MRSA (Group A), 10 MRSA-negative piglets were exposed to Group A after 2 days post-contamination, dpc (Group B) and 4 piglets were used as control group (Group C). Piglets were evaluated until 44 dpc (Group A) or at 42 days post-exposure, dpe (Group B) and then euthanized and necropsied. All nasal and skin cultures of Group A resulted MRSA-positive throughout the experiment starting from two dpc, while Group C tested always MRSA-negative. At first sampling, all Group B piglets became positive and remained positive throughout the experiment. This is the first colonization/transmission study with a CC1 LA-MRSA in pigs. The results add further knowledge on the ability of CC1 LA-MRSA to colonize pigs, and on colonization/transmission patterns, both suggesting good host adaptation., (© FEMS 2019.)

A Methicillin-resistantStaphylococcus aureus(MRSA) was isolated in Italy from a pathological sample of a mare presenting chronic purulent sinusitis and that had undergone frontal-sinus surgery three months before. Humans, horses, dogs and environmental samples were subsequently collected at the mare's stable and at the Veterinary Hospital, where the mare was operated/hospitalized, and screened for the presence of MRSA that was detected from other horses and from the environment at both sites. All the MRSA isolates belonged to clonal complex (CC)8, ST8-t11469-SCCmec-IVa, and showed similar phenotypic and genetic multidrug resistance patterns and macrorestriction-pulsed-field gel electrophoresis profiles. The only MRSA detected from humans was a CC1, ST1-t127-SCCmec-IVa. This paper represents the first report of a clinical MRSA infection in a horse in Italy. This study also supports the opinion that improper use of antibiotics and hospitalization/surgery can represent risk factors for MRSA colonization/infection in horses, and that the environment is among important sources for exposure., (© FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The cfr genes encode for a 23S rRNA methyltransferase, conferring a multiresistance phenotype to phenicol, lincosamide, oxazolidinone, pleuromutilin, and streptogramin A antibiotics. These genes have been described in staphylococci, including methicillin-resistant Staphylococcus aureus (MRSA). In this study, we retrospectively performed an in-depth genomic characterisation of three cfr-positive, multidrug-resistant (MDR) livestock-associated (LA) MRSA clonal complexes (CCs) 1 and 398 detected in different Italian pig holdings (2008–2011) during population studies on Italian livestock (2008–2014). We used a combined Illumina and Oxford Nanopore Technologies (ONT) whole genome sequencing (WGS) approach on two isolates (the 2008 CC1 and the 2010 CC398 isolates, but not the 2011 CC1 isolate). Interestingly, the three isolates presented different cfr variants, with only one displaying a linezolid-resistant phenotype. In isolate 2008 CC1, the cfr gene was identified within a Tn558 composite transposon-like structure flanked by IS elements located on a novel 44,826 bp plasmid. This represents the first report of CC1 LA-MRSA harbouring the cfr gene in its functional variant. Differently, cfr was chromosomally located in isolate 2010 CC398. Our findings have significant public health implications, confirm the need for the continuous genomic surveillance of cfr-positive zoonotic LA-MRSA, and backdate cfr presence in LA-MRSA from Italian pigs to at least 2008. [ABSTRACT FROM AUTHOR]