Epidemiology of methicillin-resistant Staphylococcus aureus isolated from the respiratory tract of Cystic Fibrosis patients

PENA AMAYA P; HAIM MS; FERNÁNDEZ S; DI GREGORIO S; TEPER A; VAZQUEZ M; LUBOVICH S; GALANTERNIK L; MOLLERACH M

Bruselas

Conferencia; 38th European Cystic Fibrosis Conference; 2015

European Cystic Fibrosis Society

MRSA colonization in Cystic Fibrosis (CF) patients attended at the Hospital de Niños ?Ricardo Gutiérrez? is an increasing problem climbing from 23% in 1995 up to 32% in 2011.ObjectiveTo analyze the diversity of MRSA isolates recovered from respiratory samples of CF patients.MethodsAntibiotic susceptibility testing (Vitek 2 or Mueller Hinton agar + 5% sheep blood, BioMérieux) was performed for all S. aureus isolates recovered from 41 out of 120 CF patients from June 2012 to May 2013. For each patient, only the first MRSA isolate was included, except when isolates with a different resistance pattern were recovered.Genotyping included mecA and lukS-lukF detection, SCCmec typing; genetic diversity was explored by Pulsed Field Gel Electrophoresis (PFGE).Results57 isolates from 41 CF patients were included. All were mecA positive and 32% PVL positive (18/57). SSCmec IV was detected in 72% (41/57). The main resistance rates were gentamicin (67%), erythromycin (56%), clindamycin (44%) and ciprofloxacin (30%). Regarding SCCmec IV, multiresistance was detected in more than 50% of the strains tested. High clone diversity was detected by PFGE, however 20/57 isolates (35%) belonged to the main Community-acquired MRSA (CA-MRSA) clone complexes previously described in Argentina (ST5-SCCmec IVa and ST30-SCCCmec IVc).ConclusionMost MRSA isolated in our centre were CA-MRSA, high multirestant and carry SCCmec type IV.