Multicenter study of clinical non-β-lactam-antibiotic susceptible MRSA strains: Genetic lineages and Panton-Valentine leukocidin (PVL) production

• Published in: Enfermedades infecciosas y microbiologia clinica Vol. 37; no. 8; pp. 509 - 513
• Main Authors: Ceballos, Sara, Aspiroz, Carmen, Ruiz-Ripa, Laura, Azcona-Gutierrez, José Manuel, López-Cerero, Lorena, López-Calleja, Ana Isabel, Álvarez, Ledicia, Gomáriz, María, Fernández, Marina, Torres, Carmen
• Format: Journal Article
• Language: English
• Published: Spain Elsevier España, S.L.U 01.10.2019
• Subjects: beta; betalactámico; CC8; Infectious Disease; lactam antibiotics; Leucocidina de Panton; Leucocidina de Panton-Valentine; mecA; mecC; methicillin; Methicillin-resistant Staphylococcus aureus; PVL; resistant staphylococcus aureus; sensible no; Sensible no-betalactámico; Staphylococcus aureus resistente a meticilina; susceptible to non; Susceptible to non-beta-lactam antibiotics; Valentine; Staphylococcus aureus resistente a meticilina; Susceptible to non-beta-lactam antibiotics; mecA; Methicillin-resistant Staphylococcus aureus; PVL; CC8; Sensible no-betalactámico; Leucocidina de Panton-Valentine; mecC
• ISSN: 0213-005X; 1578-1852
• DOI: 10.1016/j.eimc.2019.01.015

Abstract Introduction Methicillin-resistant Staphylococcus aureus (MRSA) is considered a major cause of healthcare-associated (HA) and community-acquired (CA) infections. Considering non-β-lactam susceptibility as a potential marker for mecC -MRSA and CA-MRSA, the aim of this study was to determine the frequency and the associated genetic lineages of non-beta-lactam-antibiotic susceptible MRSA (NBLS-MRSA) strains in a multicenter study in Spain. Methods A collection of 45 NBLS-MRSA strains recovered in the period from January to June 2016 from 12 Spanish hospitals was analyzed. Molecular typing through spa -type characterization, agr group and multi-locus-sequence typing was performed. Methicillin-resistant genes ( mecA and mecC ) as well as immune evasion cluster ( scn - chp - sak - sea - sep, considering scn gene as the marker of IEC system) and Panton-Valentine leukocidin (PVL) genes were determined with PCR/sequencing. Results The NBLS-MRSA phenotype was uncommon in the 12 hospitals analyzed (NBLS-MRSA/MRSA frequency: 0.3%-7.7%). All strains contained the mecA gene (and none contained mecC ). Twenty-two different spa -types were detected among NBLS-MRSA strains, with spa -t008/ agr -I the most prevalent (27%). The main clonal complexes were (CC/%): CC8/42.2%, CC5/33.3% and CC30/4.4%, with ST8 and ST5 as the main sequence types. The PVL toxin was present in 38% of strains (with spa -types t008, t024, t019, t044, t068, t318 and t3060). The IEC genes were detected in 78% of strains: IEC type-B ( n = 17), type-F ( n = 16), type-A ( n = 1) and type-E ( n = 1); 10 MRSA isolates were scn -negative. Conclusion The NBLS-MRSA phenotype is uncommon in the analyzed hospitals; although no mecC -positive strains were detected, it could be a good marker for MRSA PVL-positive isolates (38%), frequently associated with CA-MRSA infections.