Cassette Chromosome Elements Research Articles

Unearthing New ccr Genes and Staphylococcal Cassette Chromosome Elements in Staphylococci Through Genome Mining.

Staphylococcal cassette chromosome mec (SCCmec) typing is crucial for investigating methicillin-resistant Staphylococcus aureus (MRSA), relying primarily on the combination of ccr and mec gene complexes. To date, 19 ccr genes and 10 ccr gene complexes have been identified, forming 15 SCCmec types. With the vast release of bacterial genome sequences, mining the database for novel ccr gene complexes and SCC/SCCmec elements could enhance MRSA epidemiological studies. In this study, we identified 12 novel ccr genes (6 ccrA, 3 ccrB, and 3 ccrC) through mining of the National Center for Biotechnology Information (NCBI) database, forming 12 novel ccr gene complexes and 10 novel SCC elements. Overexpression of 5 groups of novel Ccr recombinases (CcrA9B3, CcrA10B1, CcrC3, CcrC4, and CcrC5) in a mutant MRSA strain lacking the ccr gene and extrachromosomal circular intermediate (ciSCC) production significantly promoted ciSCC production, demonstrating their biological activity. This discovery provides an opportunity to advance MRSA epidemiological research and develop database-based bacterial typing methods.

Novel cassette chromosome recombinases CcrA8B9 catalyse the excision and integration of the staphylococcal cassette chromosome mec element.

A defining feature of MRSA is the SCCmec element. The excision and integration of SCCmec elements are catalysed by Ccr recombinases. Currently, seven ccrA, eight ccrB and two ccrC allotypes have been described. However, there have been no recent reports of a novel Ccr recombinase and thus this area should be explored. According to the proposed criteria of the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC) committee, novel ccr genes were explored by searching the genome of our laboratory staphylococcal strains, which were isolated from bovine mastitis in Northwest China. The biological activity of the novel Ccr recombinases to excise and integrate SCCmec elements was determined. The distribution of the novel ccr genes in staphylococci was conducted by querying the NCBI nr/nt database. We report a set of novel Ccr recombinases CcrA8B9, which share nucleotide identities of 46.6%-50.2% and 47.4%-52.8% with the ccrA and ccrB alleles, respectively. We used PCR to show that CcrA8B9 can excise and integrate the SCCmec element. Furthermore, using NCBI BLAST we showed that the ccrA8B9 genes exist in other staphylococcal strains. Unlike the common ccr genes, ccrA8B9 is located outside the SCCmec/SCC element. The novel Ccr recombinases CcrA8B9 can help excise and integrate SCCmec/SCC from the genome and provide a new way to facilitate the transmission of SCCmec/SCC elements among staphylococci.

Current Status of Staphylococcal Cassette Chromosome mec (SCCmec).

Staphylococcal cassette chromosome mec (SCCmec) typing was established in the 2000s and has been employed as a tool for the molecular epidemiology of methicillin-resistant Staphylococcus aureus, as well as the evolution investigation of Staphylococcus species. Molecular cloning and the conventional sequencing of SCCmec have been adopted to verify the presence and structure of a novel SCCmec type, while convenient PCR-based SCCmec identification methods have been used in practical settings for many years. In addition, whole-genome sequencing has been widely used, and various SCCmec and similar structures have been recently identified in various species. The current status of the SCCmec types, SCCmec subtypes, rules for nomenclature, and multiple methods for identifying SCCmec types and subtypes were summarized in this review, according to the perspective of the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements.

Staphylococcal cassette chromosome mec elements from Staphylococcus intermedius group (SIG) isolates from dogs in a center for veterinary diagnostics in Brazil

ABSTRACT: Methicillin resistance in the Staphylococcus intermedius group (SIG) has emerged in small animal practice. Methicillin-resistant SIG (MRSIG) members have been implicated as causes of infections in both companion animals and humans. Staphylococcal cassette chromosome mec (SCCmec) elements carry the mecA/C genes, which encode for the transpeptidase PBP2a (PBP2’) responsible for β-lactam antibiotic resistance in staphylococci. This study examined the SCCmec types of MRSIG isolates from different clinical specimens of dogs that exhibited methicillin MIC ≥ 0.5 μg/mL by an automated identification and susceptibility system in a Center for Veterinary Diagnostics in São Paulo, Brazil. Susceptibility to methicillin was determined by broth microdilution testing, and Oxoid® M.I.C.Evaluator® strips. PBP2a production was detected using a latex agglutination assay. SCCmec typing was performed according to the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC) guidelines. SCCmec type II (2A), SCCmec type III (3A), composite SCC structures consisting of a class A mec gene complex in addition to multiple ccr gene complexes, and non-typable SCCmec elements were reported in these MRSIG isolates. SCCmec type variants differing from those so far acknowledged by IWG-SCC were found, indicating new rearrangements in the genetic context of mecA in these canine MRSIG isolates.

Structures of SCCmec elements in methicillin-resistant Staphylococcus lugdunensis are closely related to those harboured by community-associated methicillin-resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus lugdunensis (MRSL) is increasingly recognized in healthcare and community settings. To obtain a better understanding of the emergence of MRSL, this study characterized the structure and content of the SCCmec elements harboured by 36 MRSL isolates obtained from diverse sources in Hong Kong from 2008 to 2017. The isolates were investigated by whole-genome sequencing. SCCmec types and subtypes were assigned according to the guidelines from the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements. The sequence type (ST)-SCCmec combinations in the 36 MRSL isolates were as follows: ST3-SCCmec IV (n=2), ST3-SCCmec V (n=28), ST27-SCCmec V (n=5) and ST42-SCCmec V (n=1). The two SCCmec IV elements were highly similar to the SCCmec IV element harboured by the community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strain, JCSC6668. The J3-mec complex-J2 regions in the SCCmec V elements were highly similar to the corresponding regions in the CA-MRSA strains PM1 (n=13) or WIS (n=21). Based on the J1 to J3 sequences, the SCCmec V elements can be categorized into nine different subtypes. Our findings highlight the diversified structures of SCCmec elements among MRSL strains and their close relationship with SCCmec elements harboured by CA-MRSA.

Crystal Structure of an Unusual Single-Stranded DNA-Binding Protein Encoded by Staphylococcal Cassette Chromosome Elements

Methicillin-resistant Staphylococcus aureus is a global public health threat. Methicillin resistance is carried on mobile genetic elements belonging to the staphylococcal cassette chromosome (SCC) family. The molecular mechanisms that SCC elements exploit for stable maintenance and for horizontal transfer are poorly understood. Previously, we identified several conserved SCC genes with putative functions in DNA replication, including lp1413, which we found encodes a single-stranded DNA (ssDNA)-binding protein. We report here the 2.18Å crystal structure of LP1413, which shows that it adopts a winged helix-turn-helix fold rather than the OB-fold normally seen in replication-related ssDNA-binding proteins. However, conserved residues form a hydrophobic pocket not normally found in winged helix-turn-helix domains. LP1413 also has a conserved but disordered C-terminal tail. As deletion of the tail does not significantly affect cooperative binding to ssDNA, we propose that it mediates interactions with other proteins. LP1413 could play several different roles invivo.

Novel SCCmec type XIII (9A) identified in an ST152 methicillin-resistant Staphylococcus aureus

We identified a novel staphylococcal cassette chromosome mec (SCCmec) element in an ST152 methicillin-resistant Staphylococcus aureus (MRSA) isolate by combining Illumina and MinION sequencing. The element contains a new ccrC allotype designated ccrC2. The mec complex resembles mec class A, but with an altered organization of the genes. The element was acknowledged as novel by the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC) and designated SCCmec type XIII (9A).

SCCmecFinder, a Web-Based Tool for Typing of Staphylococcal Cassette Chromosome mec in Staphylococcus aureus Using Whole-Genome Sequence Data.

Typing of methicillin-resistant Staphylococcus aureus (MRSA) is important in infection control and surveillance. The current nomenclature of MRSA includes the genetic background of the S.aureus strain determined by multilocus sequence typing (MLST) or equivalent methods like spa typing and typing of the mobile genetic element staphylococcal cassette chromosome mec (SCCmec), which carries the mecA or mecC gene. Whereas MLST and spa typing are relatively simple, typing of SCCmec is less trivial because of its heterogeneity. Whole-genome sequencing (WGS) provides the essential data for typing of the genetic background and SCCmec, but so far, no bioinformatic tools for SCCmec typing have been available. Here, we report the development and evaluation of SCCmecFinder for characterization of the SCCmec element from S.aureus WGS data. SCCmecFinder is able to identify all SCCmec element types, designated I to XIII, with subtyping of SCCmec types IV (2B) and V (5C2). SCCmec elements are characterized by two different gene prediction approaches to achieve correct annotation, a Basic Local Alignment Search Tool (BLAST)-based approach and a k-mer-based approach. Evaluation of SCCmecFinder by using a diverse collection of clinical isolates (n = 93) showed a high typeability level of 96.7%, which increased to 98.9% upon modification of the default settings. In conclusion, SCCmecFinder can be an alternative to more laborious SCCmec typing methods and is freely available at https://cge.cbs.dtu.dk/services/SCCmecFinder. IMPORTANCE SCCmec in MRSA is acknowledged to be of importance not only because it contains the mecA or mecC gene but also for staphylococcal adaptation to different environments, e.g., in hospitals, the community, and livestock. Typing of SCCmec by PCR techniques has, because of its heterogeneity, been challenging, and whole-genome sequencing has only partially solved this since no good bioinformatic tools have been available. In this article, we describe the development of a new bioinformatic tool, SCCmecFinder, that includes most of the needs for infection control professionals and researchers regarding the interpretation of SCCmec elements. The software detects all of the SCCmec elements accepted by the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements, and users will be prompted if diverging and potential new elements are uploaded. Furthermore, SCCmecFinder will be curated and updated as new elements are found and it is easy to use and freely accessible.

Crystal Structure of a New Single-Stranded DNA-Binding Protein Encoded by <i>Staphylococcal</i> Cassette Chromosome Elements

Methicillin resistant Staphylococcus aureus (MRSA) is a global public-health threat. Methicillin resistance is carried on mobile genetic elements belonging to the Staphylococcal Cassette Chromosome or SCC family. The molecular mechanisms that SCC elements exploit for stable maintenance and for horizontal transfer between strains are poorly understand. Previously, we identified and characterized several conserved SCC genes with putative functions in DNA replication, including lp1413, which we found encodes a single-stranded (ss) DNA binding protein. We report here the 2.18 A crystal structure of LP1413, which shows that it adopts a winged helix-turn-helix fold rather than the OB-fold normally seen in replication-related ssDNA binding proteins. However, conserved residues form a hydrophobic pocket not normally found in winged helixturn-helix domains. LP1413 also has a conserved but disordered C-terminal tail. As we find that deletion of the tail does not affect cooperative binding to ssDNA, we propose that it mediates interactions with other proteins. We discuss roles that LP1413 could play in vivo.

Global acquisition of genetic material from different bacteria into the staphylococcal cassette chromosome elements of a Staphylococcus epidermidis isolate

Staphylococcus epidermidis has been suggested as a main reservoir of methicillin resistance and virulence genes facilitating the evolution of Staphylococcus aureus as a successful pathogen. However, it remains a mystery where and how S. epidermidis obtains these numerous genes to serve as the reservoir. In this study, methicillin-resistant S. epidermidis isolate NW32 from a mastitic milk sample was sequenced and its staphylococcal cassette chromosome (SCC) elements were characterised. The SCC composite island covered 3.5% of the genome and consisted of three intact SCC elements carrying resistance genes against β-lactam antibiotics, several heavy metals and polyamines as well as genes for utilisation of sorbitol as a carbon source. Analysis of the postulated evolutionary route suggested that the three SCC elements were assembled from genetic material from various bacterial species (staphylococci, streptococci, salinicocci and Lysinibacillus) from three habitats (human, soil and cow) in different countries (Asia, North America, South America and Europe). We propose that the hsdS restriction-modification profile and the lack of CRISPR (clustered regularly interspaced short palindromic repeat) sequences in this bacterium may facilitate the genetic exchange of SCC elements among different staphylococcal species.

The evolutionary pathway of the staphylococcal cassette chromosome element

AbstractThe staphylococcal cassette chromosome (SCC) element can carry resistance genes to antibiotics, disinfectants, and heavy metals, contributing to the survival of strains in the environment and causing difficulties in the treatment of staphylococcal infections. Methicillin resistance in staphylococci, which is of particular clinical significance, is encoded by staphylococcal cassette chromosome

Potential Spread of Methicillin-Resistant Staphylococcus aureus Recovered from Patients with Bloodstream Infection

Bloodstream infection (BSI) caused by methicillin-resistant Staphylococcus aureus (MRSA) is a worldwide public health problem, and is associated with high morbidity and mortality. Our aim was to evaluate antimicrobial resistant genes, to characterize the Staphylococcal cassette chromosome elements (SCCmec) and the genetic diversity of MRSA strains recovered from the BSI of five Hospitals in Belo Horizonte, Brazil. Fifty-six MRSA isolates were identified by the Vitek II system, and by the agar dilution method to determine the minimum inhibitory concentration. Polymerase chain reaction (PCR) was performed to detect coagulase (coa), methicillin (mecA) aminoglycosides (aaca-aphD), macrolides, lincosamides (ermA/ermB/ermC) and beta-lactams (blaz) genes, as well as chromosomal SCCmec type. The genetic diversity was carried out by ribotyping and intergenic repetitive sequences ERIC/PCR analysis. The mecA gene was detected in 84% of strains. At least one of the genes was present in the isolates from hospitals studied; the more frequent combinations were ermA/mecA and ermA/ermB/ermC (78.6% of samples). The SCC Studies have shown that such bacteria may be carriers of the ermA, ermB and ermC genes, type III was the most prevalent, followed by subtype IIIa. Ribotyping and ERIC-PCR results showed a variety of MRSA strains and suggest that certain clonal populations are circulating among the hospitals studied for different routes that should 16 be better investigated.

Analysis of Staphylococcal Cassette Chromosome mec in BD GeneOhm MRSA Assay-Negative Strains

The BD GeneOhm MRSA assay could identify methicillin-resistant Staphylococcus aureus (MRSA) strains at a high ratio (97.8%). Analysis of 11 assay-negative MRSA strains suggested that insertion of non-mec staphylococcal cassette chromosome elements (SCCs) downstream of orfX, and carriage of SCCmecs with a left extremity that cannot be detected by the kit, might lead to their being given an incorrect negative status.

Detection of staphylococcal cassette chromosome mec type XI carrying highly divergent mecA, mecI, mecR1, blaZ, and ccr genes in human clinical isolates of clonal complex 130 methicillin-resistant Staphylococcus aureus.

Methicillin resistance in staphylococci is mediated by penicillin binding protein 2a (PBP 2a), encoded by mecA on mobile staphylococcal cassette chromosome mec (SCCmec) elements. In this study, two clonal complex 130 (CC130) methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients in Irish hospitals were identified that were phenotypically PBP 2a positive but lacked mecA by conventional PCR and by DNA microarray screening. The isolates were identified as methicillin-susceptible S. aureus using the GeneXpert real-time PCR assay. Whole-genome sequencing of one isolate (M10/0061) revealed a 30-kb SCCmec element encoding a class E mec complex with highly divergent blaZ-mecA-mecR1-mecI, a type 8 cassette chromosome recombinase (ccr) complex consisting of ccrA1-ccrB3, an arsenic resistance operon, and flanking direct repeats (DRs). The SCCmec element was almost identical to that of SCCmec type XI (SCCmec XI) identified by the Sanger Institute in sequence type 425 bovine MRSA strain LGA251 listed on the website of the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements. The open reading frames (ORFs) identified within SCCmec XI of M10/0061 exhibited 21 to 93% amino acid identity to ORFs in GenBank. A third DR was identified ca. 3 kb downstream of SCCmec XI, indicating the presence of a possible SCC remnant. SCCmec XI was also identified in the second CC130 MRSA isolate by PCR and sequencing. The CC130 MRSA isolates may be of animal origin as previously reported CC130 S. aureus strains were predominantly from bovine sources. The highly divergent nature of SCCmec XI relative to other SCCmec elements indicates that it may have originated in another taxon.

Considerations for the Distinction of ccrC -Containing Staphylococcal Cassette Chromosome mec Elements

Staphylococcal cassette chromosome mec (SCCmec) elements confer methicillin resistance to the human pathogen Staphylococcus aureus (methicillin-resistant S. aureus [MRSA]). Recently, the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC) has published new guidelines for classifying different SCCmec elements (3). The new classification of SCCmec is based on the mec gene complex (classes A, B, C1, and C2) that confers methicillin resistance, the ccr gene complex composed of the recombinase-encoding ccr gene(s) (ccrA, ccrB, or ccrC) with surrounding open reading frames (ORFs) (4, 5), and joining regions (J1 to J3). The new guidelines were urgently needed due to the emergence of mosaic-structured SCCmec elements that could not be classified by the previous classification scheme. Interestingly, the classification of SCCmec elements carrying a ccrC recombinase gene appears to be more complicated than the classification of other known SCCmec elements. This is illustrated in Fig. ​Fig.1,1, which shows a comparison of all sequenced ccrC-carrying SCCmec elements. The region containing a ccrC gene flanked by three conserved upstream genes and three conserved downstream genes was denoted as a “type 5 ccr gene complex” by Ito and coworkers (4, 5) and the IWG-SCC (3), but it has also been referred to as a “ccrC-carrying unit” (1, 2). Such complexes are located either after the mec complex (e.g., in type V [5C2]), or between orfX and the mec complex (e.g., in type VII [5C1]; Fig. ​Fig.1).1). The presence of a second type 5 ccr gene complex located between orfX and the mec complex is indicated by “&5” in types V (5C2&5) (1, 2) and IV (2B&5). FIG. 1. Schematic representation of ccrC-containing SCCmec elements (adapted from reference 1). On the left, the classification proposed by the IWG-SCC is indicated. The strains carrying specific SCCmec types are indicated in the second set of parentheses. The ... Here we note that it is not easy to understand the structural differences of ccrC-carrying SCCmec elements if these are indicated only by “5” or “&5,” which may be a complication for epidemiological studies. However, by sequence comparisons, we identified several distinguishing features among the SCCmec elements carrying ccrC. Most importantly, the type 5 ccr gene complexes can be classified into two major groups (groups I and II) on the basis of the sequences of the ccrC genes and surrounding ORFs. The “group I” ccr gene complex 5 is always located between orfX and the mec complex, and it is preceded by three additional conserved genes of unknown function (Fig. ​(Fig.1).1). Comparisons of the group I regions plus the three preceding genes from SCCHg and of SCCmec elements IV (2B&5), V (5C2&5), and VII (5C1) revealed that they share more than 97% nucleotide sequence identity, underpinning the high conservation of this “extended group I” region. The group II ccr gene complex 5 is always located after the mec complex. The sequence identity within this group is about 93% due to variations in the ccrC alleles. It is thus possible to distinguish ccrC-containing SCCmec elements on the basis of these differences, and this may be more robust than a distinction based on allelic differences of ccrC (Fig. ​(Fig.11). In conclusion, we believe that the IWG-SCC recommendations provide an excellent starting point for improved SCCmec classification. However, certain refinements in the distinction of SCCmec elements as described here can possibly be applied for detecting MRSA in the years to come. Clearly, any adjustments to the SCCmec classification should be made on the basis of agreed consensus.

High Proportion of Wrongly Identified Methicillin-Resistant Staphylococcus aureus Carriers by Use of a Rapid Commercial PCR Assay Due to Presence of Staphylococcal Cassette Chromosome Element Lacking the mecA Gene

During a 9-month period, 217 patients were newly diagnosed as methicillin-resistant Staphylococcus aureus (MRSA) carriers by using a commercial rapid PCR-based test (GeneXpert). However, no MRSA was recovered by culturing the second swab in 61 of these patients. Further analyses showed that 28 (12.9%) of the patients harbored S. aureus isolates with a staphylococcal cassette chromosome element lacking the mecA gene and were thus incorrectly determined to be MRSA carriers.

Human infection associated with methicillin-resistant Staphylococcus pseudintermedius ST71

Sir, Staphylococcus pseudintermedius is one of the most common pathogens isolated from skin and post-operative infections in dogs and cats and can also occasionally cause infections in humans. People working or living with animals are more likely to be colonized with S. pseudintermedius in their nasal cavities and human infection acquired from dogs has been recently reported. In recent years, there have been increasing numbers of infections in dogs and cats caused by methicillin-resistant S. pseudintermedius (MRSP) and a predominant MRSP clone is disseminating in dogs and cats throughout Europe. This MRSP clone belongs to the multilocus sequence type (MLST) ST71, spa type t02 and SmaI PFGE group J (ST71-t02-J) and contains the staphylococcal cassette chromosome element SCCmec II–III. It displays resistance to many classes of antibiotics and represents a challenge for therapy. Here, we report, to our knowledge, the first case of a human infection caused by MRSP ST71 emphasizing its zoonotic potential and therapeutic challenge. An adult patient presented to the doctor in 2009 with headache, watery eyes and a small oedema over the right eye. The patient had a history of recurrent rhinosinusitis and three surgical interventions had been performed over the previous 6 years, the last one in 2005. CT illustrated an obliteration of the right sinus frontalis with an expansive mucocele. Yet another surgical intervention was absolutely essential and post-operative treatment for 3 weeks with 500 mg of ciprofloxacin twice per day and 300 mg of clindamycin three times per day was given. Five weeks post-operatively, a purulent infection appeared. After 10 days of treatment with 875 mg of amoxicillin/125 mg of clavulanic acid twice daily and 300 mg of clindamycin three times daily and no improvement, a sample was sent for bacteriological analysis. The laboratory identified a multidrug-resistant Staphylococcus belonging to the Staphylococcus intermedius group (SIG) using the ID 32 STAPH system (bioMerieux, Marcy l’Etoile, France) and disc diffusion susceptibility testing (Oxoid Ltd, Basingstoke, UK). Based on these results, a local treatment with fusidic acid gauze and application of 2% mupirocin ointment four times a day for 8 days followed by a topical glucocorticoid/antibiotic combination therapy (0.5 mg/g fluocinonide, 2.5 mg/g neomycin, 0.25 mg/g gramicidin and 100000 IU/g nystatin) packing for 4 days improved the local condition. Six weeks after the purulent infection, the wound had healed with scarring and no bacterium was detectable in a repeat smear. Local follow-up treatment with steroids and routine check-ups confirmed the absence of residual infection. The multidrug-resistant Staphylococcus isolate was further identified as MRSP ST71-t02-J containing SCCmec II–III using MLST typing, spa typing, PFGE and SCCmec typing methods described previously. MICs of antibiotics were determined in Mueller–Hinton broth using custom Sensititre susceptibility NLV73 plates (Trek Diagnostics System, East Grinstead, UK) except for rifampicin, trimethoprim, kanamycin and fusidic acid, which were tested using home-made microbroth dilution plates. Antibiotic resistance genes were detected using a microarray. Mutations in topoisomerase genes gyrA and grlA were identified by sequencing of PCR products (Table 1). The isolate was susceptible to the antibiotics amikacin, chloramphenicol, fusidic acid, linezolid, nitrofurantoin, the combination quinupristin/dalfopristin, rifampicin and vancomycin (Table 1). The patient owned a male dog that needed home care because of various clinical problems such as diabetes, recurrent warts and abdominal tumour. The dog had consultations in various clinics and underwent several antibiotic treatments (details of substances could not be ascertained). The dog was euthanized before samples could be taken to determine whether it was a carrier of the strain. The patient also owned horses and cats; all of them were in good health without clinical signs. Even if the ultimate source of the MRSP infection could not be identified, the patient was infected with the same MRSP clone (ST71-t02-J with SCCmec II–III) that has been disseminating in dogs over Europe in recent years. A case similar to the one reported here has been described in the USA, where a woman developed sinusitis caused by a methicillinresistant SIG whose origin could be attributed to her pet dog. In that case, vancomycin and linezolid were used for treatment. The increasing number of dogs carrying MRSP constitutes a risk for pet owners to become colonized with MRSP, and MRSP infections in humans may also increase in the near future. It is therefore important to recognize MRSP as a zoonotic pathogen and have antibiotics available for the treatment of MRSP infections in humans. Therefore, antibiotics such as mupirocin, linezolid, quinupristin/dalfopristin, rifampicin and vancomycin that are used for decolonization or as ‘last resort antibiotics’ against methicillin-resistant staphylococci in humans should not be used for treatment in animals.