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?

• Published in: International journal of medical microbiology Vol. 304; no. 8; pp. 1226 - 1232
• Main Authors: Benito, Daniel, Lozano, Carmen, Rezusta, Antonio, Ferrer, Isabel, Vasquez, Maria Alejandra, Ceballos, Sara, Zarazaga, Myriam, Revillo, Maria José, Torres, Carmen
• Format: Journal Article
• Language: English
• Published: Germany Elsevier GmbH 01.11.2014
• Subjects: Animal contact; Animals; CC1; CC398; Drug Resistance, Multiple, Bacterial; Hospitals; Humans; Infectious Disease; Livestock; Livestock associated MRSA; Medical Education; Methicillin-Resistant Staphylococcus aureus - classification; Methicillin-Resistant Staphylococcus aureus - drug effects; Methicillin-Resistant Staphylococcus aureus - isolation & purification; Molecular Epidemiology; Molecular Typing; Multi-resistance; Occupational Exposure; Risk Factors; Spain; Staphylococcal Infections - epidemiology; Staphylococcal Infections - microbiology; Staphylococcus aureus; Tetracycline; Tetracycline Resistance; Spain; CC1; Multi-resistance; Livestock associated MRSA; Animal contact; CC398; Tetracycline
• ISSN: 1438-4221; 1618-0607
• DOI: 10.1016/j.ijmm.2014.09.004

Abstract Tetracycline-resistance (TetR ) has been postulated as a marker of the livestock-associated methicillin-resistant Staphylococcus aureus (MRSA) lineage CC398. Objectives of the study: to determine the spa -types and assigned MLST clonal complexes (CCs) among all 98 MRSA-TetR 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-TetR -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.