title: Characterization of tetracycline and methicillin resistant Staphylococcus aureus strains in a Spanish hospital: is livestock-contact a risk factor in infections caused by MRSA CC398?
abstract: Tetracycline-resistance (Tet(R)) has been postulated as a marker of the livestock-associated methicillin-resistant Staphylococcus aureus (MRSA) lineage CC398.
  
  
  OBJECTIVE
  to determine the spa-types and assigned MLST clonal complexes (CCs) among all 98 MRSA-Tet(R) strains recovered during 2011-2012 (from different patients) in a Spanish Hospital, analyzing the possible correlation with livestock-contact of the patients. All 98 strains were assigned to 9 CCs: CC398 (60.2%), CC1 (19.4%), CC5 (12.2%), and other CCs (8.2%). The 98 patients were classified into three groups: (A) contact with livestock-animals (n=25); (B) no-contact with livestock-animals (n=42); (C) no information about animal contact (n=31). A significant higher percentage of CC398 strains was obtained in group A (76%) than in group B (50%) (p<0.05), being the percentage in group C of 61.3%. Most of MRSA-Tet(R)-CC398 strains presented a multi-resistance phenotype, including erythromycin, clindamycin, and ciprofloxacin, and the most prevalent detected genes were tet(M) and erm(C). Three strains presented the phenotype macrolide-susceptibility/lincosamide-resistance and contained the vga(A) gene. MRSA-CC1 strains showed higher percentages of erythromycin/clindamycin resistance (95%/89%) than MRSA-CC398 strains (58%/63%), and this resistance was usually mediated by erm(C) gene. Most of MRSA-CC5 strains showed resistance to ciprofloxacin, tobramycin/kanamycin and erythromycin. None of the strains presented the genes lukF/lukS-PV, tsst-1, eta, etb or etd. All MRSA-CC398 strains lacked the genes of the immune-evasion-cluster, but MRSA-CC1 strains carried these genes (type E). In conclusion, although MRSA CC398 is detected in a significant higher proportion in patients with livestock-contact; its detection in people without this type of contact also indicates its capacity for human-to-human transmission.
authors.affiliation: Area de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Benito
authors.affiliation: Area de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Lozano
authors.affiliation: Servicio de Microbiología, Hospital Universitario Miguel Servet, IIS Aragón, Zaragoza, Spain; Universidad de Zaragoza, Zaragoza, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Rezusta
authors.affiliation: Servicio de Microbiología, Hospital Universitario Miguel Servet, IIS Aragón, Zaragoza, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Ferrer
authors.affiliation: Servicio de Microbiología, Hospital Universitario Miguel Servet, IIS Aragón, Zaragoza, Spain.
authors.forename: Maria Alejandra
authors.initials: MA
authors.lastname: Vasquez
authors.affiliation: Area de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Ceballos
authors.affiliation: Area de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain.
authors.forename: Myriam
authors.initials: M
authors.lastname: Zarazaga
authors.affiliation: Servicio de Microbiología, Hospital Universitario Miguel Servet, IIS Aragón, Zaragoza, Spain.
authors.forename: Maria José
authors.initials: MJ
authors.lastname: Revillo
authors.affiliation: Area de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain. Electronic address: carmen.torres@unirioja.es.
authors.forename: Carmen
authors.initials: C
authors.lastname: Torres
mesh_terms: D000818:Animals; D024901:Drug Resistance, Multiple, Bacterial; D006761:Hospitals; D006801:Humans; D058751:Livestock; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D017720:Molecular Epidemiology; D058889:Molecular Typing; D016273:Occupational Exposure; D012307:Risk Factors; D013030:Spain; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D013753:Tetracycline Resistance
keywords: Animal contact; CC1; CC398; Livestock associated MRSA; Multi-resistance; Tetracycline