BACKGROUND: Meticillin-resistant Staphylococcus aureus (MRSA) is a significant cause of mortality and morbidity in healthcare and community settings; however, there is a paucity of large-scale, longitudinal studies monitoring the occurrence of MRSA in the care home setting. AIM: To determine the molecular epidemiology of MRSA colonizing elderly residents of care homes. METHODS: Residents in 65 care homes in Leeds, UK, were screened for MRSA nasal colonization in four consecutive years (2006-2009). Isolates were characterized using antibiotic susceptibility testing, detection of the Panton-Valentine leucocidin (PVL) locus, accessory gene regulator allotyping, characterization of the staphylococcal cassette chromosome mec element, spa-typing and pulsed-field gel electrophoresis. FINDINGS: MRSA was recovered from 888 nasal swabs of 2492 residents and prevalence was similar (19-22%) throughout the study. Resistance to ≥3 antibiotic classes was common (34%), but resistance to only β-lactam agents was rare (3%); no PVL-positive isolates were identified. Most isolates were related to healthcare-associated epidemic-MRSA type 15 (EMRSA-15, ST22-IV); such isolates decreased in prevalence during the study (86-72%; P < 0.0001, χ(2)-test). The remainder belonged to five different multi-locus sequence type clonal complexes (CC). Most notably, CC59 strains increased in prevalence (10-25%; P < 0.0001, χ(2)-test) and were associated with high-level mupirocin resistance. CONCLUSIONS: The molecular epidemiology of MRSA in care homes is complex and dynamic. There was a high, consistent prevalence of MRSA nasal colonization, dominated by healthcare-associated strains. Vigilance is recommended; however, as high-level mupirocin resistance was associated with a single clonal group (CC59) that significantly increased in prevalence during the study.
BACKGROUND:Meticillin-resistant Staphylococcus aureus (MRSA) is a significant cause of mortality and morbidity in healthcare and community settings; however, there is a paucity of large-scale, longitudinal studies monitoring the occurrence of MRSA in the care home setting. AIM: To determine the molecular epidemiology of MRSA colonizing elderly residents of care homes. METHODS: Residents in 65 care homes in Leeds, UK, were screened for MRSA nasal colonization in four consecutive years (2006-2009). Isolates were characterized using antibiotic susceptibility testing, detection of the Panton-Valentine leucocidin (PVL) locus, accessory gene regulator allotyping, characterization of the staphylococcal cassette chromosome mec element, spa-typing and pulsed-field gel electrophoresis. FINDINGS: MRSA was recovered from 888 nasal swabs of 2492 residents and prevalence was similar (19-22%) throughout the study. Resistance to ≥3 antibiotic classes was common (34%), but resistance to only β-lactam agents was rare (3%); no PVL-positive isolates were identified. Most isolates were related to healthcare-associated epidemic-MRSA type 15 (EMRSA-15, ST22-IV); such isolates decreased in prevalence during the study (86-72%; P < 0.0001, χ(2)-test). The remainder belonged to five different multi-locus sequence type clonal complexes (CC). Most notably, CC59 strains increased in prevalence (10-25%; P < 0.0001, χ(2)-test) and were associated with high-level mupirocin resistance. CONCLUSIONS: The molecular epidemiology of MRSA in care homes is complex and dynamic. There was a high, consistent prevalence of MRSA nasal colonization, dominated by healthcare-associated strains. Vigilance is recommended; however, as high-level mupirocin resistance was associated with a single clonal group (CC59) that significantly increased in prevalence during the study.
Authors: S T Almeida; S Nunes; A C S Paulo; N A Faria; H de Lencastre; R Sá-Leão Journal: Eur J Clin Microbiol Infect Dis Date: 2014-10-31 Impact factor: 3.267
Authors: Ewan M Harrison; Catherine Ludden; Hayley J Brodrick; Beth Blane; Gráinne Brennan; Dearbháile Morris; Francesc Coll; Sandra Reuter; Nicholas M Brown; Mark A Holmes; Brian O'Connell; Julian Parkhill; M Estee Török; Martin Cormican; Sharon J Peacock Journal: Genome Med Date: 2016-10-03 Impact factor: 11.117
Authors: Richard Aschbacher; Elisabetta Pagani; Massimo Confalonieri; Claudio Farina; Paolo Fazii; Francesco Luzzaro; Pier Giorgio Montanera; Aurora Piazza; Laura Pagani Journal: Antimicrob Resist Infect Control Date: 2016-10-11 Impact factor: 4.887
Authors: Camila Sena Martins de Souza; Carlos Magno Castelo Branco Fortaleza; Claudia Lima Witzel; Mônica Silveira; Mariana Fávero Bonesso; Silvio Alencar Marques; Maria de Lourdes Ribeiro de Souza da Cunha Journal: Ann Clin Microbiol Antimicrob Date: 2016-02-16 Impact factor: 3.944