Community-associated Staphylococcus aureus pneumonia among Greek children: epidemiology, molecular characteristics, treatment, and outcome

Abstract

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.

Six-Year Retrospective Review of Hospital Data on Antimicrobial Resistance Profile of Staphylococcus aureus Isolated from Skin Infections from a Single Institution in Greece

“…We found increased resistance for clindamycin (18%) but low for STX (4.6%), however 38% and 12.5% of MRSA isolates were resistant to clindamycin and STX, respectively. Our results are similar for clindamycin but much higher for STX compared with previous studies in Greek hospitals [ 12 , 18 , 19 ]. The high resistance to clindamycin limits its use for SSTI but STX may still be an option.…”

“…Our study shows high resistance of S. aureus strains to erythromycin (34.4%), much higher for MRSA (60%), making macrolides an unsuitable first-line choice for treatment of skin infections. Similar (31.7%) [ 18 ] or higher (49%) [ 19 ] rates of resistance to macrolides have been reported from other studies performed in Greece. Clindamycin is a bacteriostatic agent that is favored in the setting of staphylococcal skin infection due to its excellent skin penetration [ 20 ].…”

Methicillin-Resistant Staphylococcus aureus ST80 Clone: A Systematic Review

“…This clone was also reported from other types of infections including fatal pneumonia and bloodstream infections [14,61,77,79]. In the study by Doudoulakakis et al, the authors reported that MRSA-ST80 PVL+ strains accounted for 95% of CA-MRSA pneumonia cases [14]. Nikolaras et al showed that 8% of MRSA strains isolated from bloodstream infections were assigned to MRSA-ST80 clone [77].…”

“…Epidemiological studies of MRSA-ST80 PVL+ have revealed that these strains are primarily associated with recurrent, chronic, or particularly severe SSTIs, such as furuncles and abscesses [114]. This clone was also reported from other types of infections including fatal pneumonia and bloodstream infections [14,61,77,79]. In the study by Doudoulakakis et al, the authors reported that MRSA-ST80 PVL+ strains accounted for 95% of CA-MRSA pneumonia cases [14].…”

Molecular Epidemiology of the Community-Associated Methicillin-Resistant Staphylococcus Aureus Clones: A Synthetic Review

“…In contrast to North America, CA-MRSA in Europe is characterized by bigger clonal heterogeneity. The predominant European clone is ST80-IV ( Figure 1 ), resistant to kanamycin/amikacin and fusidic acid [ 20 – 21 ], strongly associated with skin and soft tissue infections, rarely found among asymptomatic carriers. ST80 was first reported in 1993, but was relatively rare until the late 1990s [ 22 ].…”