An increase in erythromycin resistance in methicillin-susceptible Staphylococcus aureus from blood correlates with the use of macrolide/lincosamide/streptogramin antibiotics. EARS-Net Spain (2004-2020).

Objectives: To describe and analyse erythromycin resistance trends in blood isolates of Staphylococcus aureus (EARS-Net Spain, 2004-2020) and the association of these trends with the consumption of macrolide, lincosamide, and streptogramin B (MLSB) antibiotics. To assess molecular changes that could be involved in erythromycin resistance trends by whole genome analysis of representative isolates. Materials and methods: We collected antibiotic susceptibility data for all first-blood S. aureus isolates in patients from 47 Spanish hospitals according to EARS-Net criteria. MLSB antibiotic consumption was obtained from the Spanish Agency for Medicines and Medical Devices (2008-2020). We sequenced 137 representative isolates for core genome multilocus sequence typing, resistome and virulome analysis. Results: For the 36,612 invasive S. aureus isolates, methicillin resistance decreased from 26.4% in 2004 to 22.4% in 2020. Erythromycin resistance in methicillin-susceptible S. aureus (MSSA) increased from 13.6% in 2004 to 28.9% in 2020 (p < 0.001); however, it decreased from 68.7 to 61.8% (p < 0.0001) in methicillin-resistant S. aureus (MRSA). Total consumption of MLSB antibiotics increased from 2.72 defined daily doses per 1,000 inhabitants per day (DID) in 2014 to 3.24 DID in 2016. By WGS, the macrolide resistance genes detected were erm (59.8%), msrA (46%), and mphC (45.2%). The erm genes were more prevalent in MSSA (44/57, 77.2%) than in MRSA (38/80, 47.5%). Most of the erm genes identified in MSSA after 2013 differed from the predominant ermC gene (17/22, 77.3%), largely because ermT was significantly associated with MSSA after 2013 (11/29, 37.9%). All 13 ermT isolates in this study, except one, belonged to ST398 and came from 10 hospitals and six Spanish provinces. Conclusion: The significant increase in erythromycin resistance in blood MSSA correlated with the consumption of the MLSB antibiotics in Spain. These preliminary data seem support the hypothesis that the human ST398 MSSA clade with ermT-mediated resistance to erythromycin may be involved in this trend.

Analysis of the results of the SEIMC External Quality Control Program. Year 2016. / Análisis de resultados del Programa de Control de Calidad Externo SEIMC. Año 2016.

The External Quality Control Programme of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) includes controls for bacteriology, serology, mycology, parasitology, mycobacteria, virology, molecular microbiology, and genotypic bacterial resistance. As in previous years, the results obtained in 2016 confirm the excellent skill and good technical standards in the vast majority of clinical microbiology laboratories in Spain. However, erroneous results can be obtained in any laboratory and in clinically relevant determinations. Once again, the results of this programme highlight the need to implement both internal and external controls. Supplement information: This article is part of a supplement entitled «SEIMC External Quality Control Programme. Year 2016¼, which is sponsored by Roche, Vircell Microbiologists, Abbott Molecular and Francisco Soria Melguizo, S.A. © 2019 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

[Analysis of the results of the SEIMC External Quality Control Program. Year 2011]. / Análisis de resultados del Programa Externo de Control de Calidad SEIMC. Año 2011.

The External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology (Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica [SEIMC]) includes controls for bacteriology, serology, mycology, parasitology, mycobacteria, virology, and molecular microbiology. This article presents the most relevant conclusions and lessons from the 2011 controls. Overall, the results obtained in 2011 confirm the excellent skill and good technical standards found in previous years. Nevertheless, erroneous results can be obtained in any laboratory and in clinically relevant determinations. The results of this program highlight the need to implement both internal and external controls, such as those offered by the SEIMC program, in order to ensure maximal quality of microbiological tests.

[Analysis of the results of the 2010 External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology]. / Análisis de resultados del Programa Externo de Control de Calidad SEIMC. Año 2010.

The External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology includes controls for bacteriology, serology, mycology, parasitology, mycobacteria, virology and molecular microbiology. This article presents the most important conclusions and lessons of the 2010 controls. As a whole, the results obtained in 2010 confirm the excellent skill and good technical standards found in previous years. However, erroneous results can be obtained in any laboratory and in clinically relevant determinations. The results of this program highlight the need to implement both internal and external controls to ensure maximal quality of microbiological tests(1).