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Volume 20, Number 5—May 2014

Staphylococcus aureus Carrying mecC Gene in Animals and Urban Wastewater, Spain

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To the Editor: A new methicillin resistance mechanism gene, a divergent mecA homologue named mecC (formerly mecALGA251), was recently described in Staphylococcus aureus (1). Methicillin-resistant S. aureus (MRSA) isolates carrying mecC have been recovered from humans, ruminants, pets, and other animals such as rats, seals, and guinea pigs (13). It has been suggested that mecC-carrying MRSA isolates might not be detected by using MRSA selective media (4). For mecC-carrying S. aureus isolates, cefoxitin MICs of 4–64 mg/L have been demonstrated (12,4), values that would normally include susceptible isolates, according to the epidemiologic cutoff value established by the European Committee on Antibiotic Susceptibility Testing (EUCAST; mecC-carrying S. aureus isolates have been classified as heteroresistant (5), and MICs can be affected by the drug-susceptibility testing method used (1,5).

These observations led us to retrospectively investigate the presence of mecC gene in a set of 361 mecA-negative S. aureus isolates collected during 2009–2012 (Table), independently of their susceptibility to cefoxitin. Isolates were recovered from healthy carriers in livestock (n = 39), from wild animals (n = 254), and from wastewater (effluents) from an urban sewage plant (n = 68). Specific amplification of the mecC gene was performed as described (6). The mecC-carrying S. aureus isolates were tested by broth microdilution using Microtiter EUST plates (Trek Diagnostic Systems, East Grinstead, UK) for susceptibility to benzylpenicillin, cefoxitin, chloramphenicol, ciprofloxacin, clindamycin, erythromycin, florfenicol, fusidic acid, gentamicin, kanamycin, linezolid, mupirocin, rifampin, sulfamethoxazole, streptomycin, quinupristin-dalfopristin, tetracycline, thiamulin, trimethoprim, and vancomycin. Additionally, susceptibility to oxacillin was determined by using microScan Gram Positive Combo panel 37 (Siemens, Erlangen, Germany). MICs were interpreted according to EUCAST epidemiologic cutoff values.

mecC was detected in a total of 4 isolates from wild boar (n = 1), fallow deer (n = 2), and urban wastewater (n = 1); these isolates represent 1% of the 361 tested isolates. The 3 isolates recovered from animals were susceptible to all antimicrobial drugs tested other than β-lactams and to oxacillin (MICs 0.5–1 mg/L) but were resistant to penicillin (MICs 0.5–2 mg/L). Two of the isolates were resistant to cefoxitin (MICs 8 and 16 mg/L) and the third was susceptible (MIC 4 mg/L). The wastewater isolate was resistant to penicillin (MIC 2 mg/L) and erythromycin (MIC 16 mg/L) and susceptible to all other antimicrobial drugs tested, including cefoxitin (MIC 4 mg/L) and oxacillin (MIC ≤0.25 mg/L).

Previous studies have described mecC-positive isolates as susceptible to all antimicrobial drugs tested except β-lactams (2,3), although sporadic resistance to fluoroquinolones has been found (4,7). We additionally found erythromycin resistance in 1 mecC-carrying S. aureus isolate. For the 4 mecC-carrying S. aureus isolates we detected, MICs of oxacillin were interpreted as susceptible, and 2 isolates were susceptible to cefoxitin according to EUCAST guidelines, findings that agree with previous reports (12,4). Thus, mecC presence is not always linked to resistance phenotypes for cefoxitin or oxacillin; such unclear findings could hinder the detection of mecC-carrying isolates.

We further characterized the 4 mecC-carrying S. aureus isolates by spa typing and detection of Panton-Valentin leukocidin (PVL) toxin genes (6,8). Multilocus sequence typing (MLST) was performed according to Enright et al. (9) by using self-designed primers arc (down 5′-CGATTTGTTGTTGATTAGGTTC-3′), tpi (up 5′-CATTAGCAGATTTAGGCGTTA-3′), and yqiL (down 5′-GATTGGYTCACCTTTRCGTTG-3′). All 4 isolates were PVL negative. The 3 animal isolates were assigned to a new spa type (t11212) and to clonal complex (CC) 425 and sequence type (ST) 425 (Table). ST425 has been previously associated with mecC-carrying S. aureus isolates in cattle and humans (12); the animals we sampled were from a game estate and may have had contact with cattle and with urban wastewater. The wastewater isolate was assigned to spa type t843 and to a new allelic profile, ST2676, in CC130 (Table). ST2676 represents a single-locus variant of ST130 carrying a different allele for the gene aroE. MRSA isolates of CC130 have been associated with humans and animals (14,6). This result indicates that mecC-carrying S. aureus isolates can be found in urban wastewater, which may act as an environmental reservoir, as has been demonstrated for mecA-carrying S. aureus (10).

In conclusion, we detected the methicillin resistance mechanism gene mecC in nonclinical S. aureus isolates from animals and urban wastewater in Spain. Although our data indicate that the frequency of this resistance mechanism is low, this gene appears to be expanding to new areas. Prospective studies should be performed to evaluate epidemiologic changes and to analyze the genetic lineages that carry this resistance mechanism.


M. Concepción Porrero, Aránzazu Valverde, Pedro Fernández-Llario1, Alberto Díez-Guerrier, Ana Mateos, Santiago Lavín, Rafael Cantón, José-Francisco Fernández-Garayzabal, and Lucas DomínguezComments to Author 
Author affiliations: Universidad Complutense, Madrid, Spain (M.C. Porrero, A. Valverde, A. Díez-Guerrier, A. Mateos, J.-F. Fernández-Garayzabal, L. Domínguez); Universidad de Extremadura, Cáceres, Spain (P. Fernández-Llario); Universitat Autònoma de Barcelona, Bellaterra, Spain (S. Lavín); Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid (R. Cantón)



  1. García-Álvarez  L, Holden  MT, Lindsay  H, Webb  CR, Brown  DF, Curran  MD, Meticillin-resistant Staphylococcus aureus with a novel mecA homologue in human and bovine populations in the UK and Denmark: a descriptive study. Lancet Infect Dis. 2011;11:595603. DOIPubMedGoogle Scholar
  2. Paterson  GK, Larsen  AR, Robb  A, Edwards  GE, Pennycott  TW, Foster  G, The newly described mecA homologue, mecALGA251, is present in methicillin-resistant Staphylococcus aureus isolates from a diverse range of host species. J Antimicrob Chemother. 2012;67:280913. DOIPubMedGoogle Scholar
  3. Walther  B, Wieler  LH, Vincze  S, Antao  EM, Brandenburg  A, Stamm  I, MRSA variant in companion animals. Emerg Infect Dis. 2012;18:201720. DOIPubMedGoogle Scholar
  4. Cuny  C, Layer  F, Strommenger  B, Witte  W. Rare occurrence of methicillin-resistant Staphylococcus aureus CC130 with a novel mecA homologue in humans in Germany. PLoS ONE. 2011;6:e24360. DOIPubMedGoogle Scholar
  5. Kim  C, Milheirico  C, Gardete  S, Holmes  MA, Holden  MT, de Lencastre  H, Properties of a novel PBP2A protein homolog from Staphylococcus aureus strain LGA251 and its contribution to the beta-lactam-resistant phenotype. J Biol Chem. 2012;287:3685463. DOIPubMedGoogle Scholar
  6. Stegger  M, Andersen  PS, Kearns  A, Pichon  B, Holmes  MA, Edwards  G, Rapid detection, differentiation and typing of methicillin-resistant Staphylococcus aureus harbouring either mecA or the new mecA homologue mecA(LGA251). Clin Microbiol Infect. 2012;18:395400. DOIPubMedGoogle Scholar
  7. Petersen  A, Stegger  M, Heltberg  O, Christensen  J, Zeuthen  A, Knudsen  LK, Epidemiology of methicillin-resistant Staphylococcus aureus carrying the novel mecC gene in Denmark corroborates a zoonotic reservoir with transmission to humans. Clin Microbiol Infect. 2013;19:E1622. DOIPubMedGoogle Scholar
  8. Harmsen  D, Claus  H, Witte  W, Rothganger  J, Turnwald  D, Vogel  U. Typing of methicillin-resistant Staphylococcus aureus in a university hospital setting by using novel software for spa repeat determination and database management. J Clin Microbiol. 2003;41:54428 . DOIPubMedGoogle Scholar
  9. Enright  MC, Day  NP, Davies  CE, Peacock  SJ, Spratt  BG. Multilocus sequence typing for characterization of methicillin-resistant and methicillin-susceptible clones of Staphylococcus aureus. J Clin Microbiol. 2000;38:100815 .PubMedGoogle Scholar
  10. Börjesson  S, Matussek  A, Melin  S, Lofgren  S, Lindgren  PE. Methicillin-resistant Staphylococcus aureus (MRSA) in municipal wastewater: an uncharted threat? J Appl Microbiol. 2010;108:124451 . DOIPubMedGoogle Scholar




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DOI: 10.3201/eid2005.130426

1Current affiliation: Innovación en Gestión y Conservación de Ungulados S.L., Cáceres, Spain.

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Lucas Domínguez, Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Universidad Complutense, Avenida Puerta de Hierro s/n 28040, Madrid, SpainLucas Domínguez, Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Universidad Complutense, Avenida Puerta de Hierro s/n 28040, Madrid, Spain

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