Community-associated Staphylococcus aureus pneumonia among Greek children: epidemiology, molecular characteristics, treatment, and outcome.Staphylococcus aureus is an infrequent cause of community-associated (CA-SA) pneumonia in children.  The aim of this study was to evaluate the clinical, epidemiological, microbiological, and molecular characteristics of CA-SA pneumonia among children hospitalized in two large tertiary care referral centers during an 8-year period.  Cases of CA-SA pneumonia admitted between 2007 and 2014 were retrospectively examined through medical record review.  Molecular investigation was performed for available strains; mecA, Panton-Valentine leukocidin (PVL) (lukS-lukF-PV), and fibronectin binding protein A (fnbA) genes were detected by polymerase chain reaction (PCR).  Clones were assigned by agr groups, pulsed-field gel electrophoresis (PFGE), SCCmec, and multilocus sequencing typing (MLST).  In total, 41 cases were recorded (boys, 61 %), with a median age of 4.3 months (range, 1-175).  Methicillin-resistant S. aureus (MRSA) accounted for 31 cases (75.6 %).  Complications included empyema (25/41, 61 %), pneumatoceles (7/41, 17 %), and lung abscess (1/41, 2.5 %).  Intensive care unit (ICU) admission was required in 58.5 %.  Two deaths occurred (4.9 %).  Definitive therapy was based on vancomycin with or without other antibiotics (55.9 %), followed by clindamycin and linezolid (26.5 % each).  All isolates were susceptible to vancomycin (MIC90 2 mg/L, range 1-2), teicoplanin, and linezolid, whereas 26.8 % were resistant to clindamycin.  Among the 25 studied strains, 20 were mecA-positive (MRSA), carrying also the fnbA gene.  Of these, 90 % belonged to the ST80-IV/agr3/PVL-positive clone.  Methicillin-susceptible S. aureus (MSSA) strains showed polyclonality, 3/5 were PVL-positive, and 3/5 were fnbA-positive.  MRSA and particularly the ST80-IV clone predominated among staphylococcal pneumonia cases in children.  Treatment provided was effective in all but two patients, despite the relatively high minimum inhibitory concentration (MIC) of vancomycin and a high resistance to clindamycin.
C
Definitive therapy was based on vancomycin with or without other antibiotics (55.9 %), followed by clindamycin and linezolid (26.5 % each).  All isolates were susceptible to vancomycin (MIC90 2 mg/L, range 1-2), teicoplanin, and linezolid, whereas 26.8 % were resistant to clindamycin.  Treatment provided was effective in all but two patients, despite the relatively high minimum inhibitory concentration (MIC) of vancomycin and a high resistance to clindamycin.
vancomycin
Definitive therapy was based on vancomycin with or without other antibiotics (55.9 %), followed by clindamycin and linezolid (26.5 % each).  All isolates were susceptible to vancomycin (MIC90 2 mg/L, range 1-2), teicoplanin, and linezolid, whereas 26.8 % were resistant to clindamycin.  Treatment provided was effective in all but two patients, despite the relatively high minimum inhibitory concentration (MIC) of vancomycin and a high resistance to clindamycin.
clindamycin
Definitive therapy was based on vancomycin with or without other antibiotics (55.9 %), followed by clindamycin and linezolid (26.5 % each).  All isolates were susceptible to vancomycin (MIC90 2 mg/L, range 1-2), teicoplanin, and linezolid, whereas 26.8 % were resistant to clindamycin. 
linezolid