Panton-Valentine leukocidin-producing Staphylococcal aureus: report of four siblings

Serious Complications from Staphylococcal aureus in Atopic Dermatitis

Colonization with Staphylococcal aureus is markedly more frequent in individuals with atopic dermatitis (AD) than in unaffected individuals. Chronic scratching leads to worsening of an existing defect in the epidermal barrier, which can allow S. aureus invasion into the bloodstream and subsequent systemic infections. We report two unusual cases of systemic illness in individuals with AD. One developed infective endocarditis followed by a stroke and the other developed septic arthritis and osteomyelitis. We performed an extensive literature review of reported systemic complications caused by S. aureus in patients with AD. Although reports are rare, practitioners should be aware of these important, albeit unlikely, complications of staphylococcal superinfections in individuals with AD.

[Fatal Panton-Valentine leukocidine-associated Staphylococcus aureus necrotizing pneumonia]

Panton-Valentine leukocidin-producing Staphylococcus aureus necrotizing pneumonia is an unusual cause of community-acquired pneumonia associated with a high fatality rate. The specificities of its presentation must be known by the critical care doctor, in order to quickly make the diagnosis and start the right antibiotics and discuss adjunctive therapy with intravenous immunoglobin. Moreover, the management of close contacts (household and healthcare workers) of patient with such a pneumonia is not well-known. The present case report underlines the clinical presentation of this pneumonia, the specificities of its treatment, and specifies the management of close contacts.

Panton-Valentine leukocidin-positive Staphylococcus aureus in Ireland from 2002 to 2011: 21 clones, frequent importation of clones, temporal shifts of predominant methicillin-resistant S. aureus clones, and increasing multiresistance

There has been a worldwide increase in community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA) infections. CA-MRSA isolates commonly produce the Panton-Valentine leukocidin toxin encoded by the pvl genes lukF-PV and lukS-PV. This study investigated the clinical and molecular epidemiologies of pvl-positive MRSA and methicillin-susceptible S. aureus (MSSA) isolates identified by the Irish National MRSA Reference Laboratory (NMRSARL) between 2002 and 2011. All pvl-positive MRSA (n=190) and MSSA (n=39) isolates underwent antibiogram-resistogram typing, spa typing, and DNA microarray profiling for multilocus sequence type, clonal complex (CC) and/or sequence type (ST), staphylococcal cassette chromosome mec type assignment, and virulence and resistance gene detection. Where available, patient demographics and clinical data were analyzed. The prevalence of pvl-positive MRSA increased from 0.2% to 8.8%, and that of pvl-positive MSSA decreased from 20% to 2.5% during the study period. The pvl-positive MRSA and MSSA isolates belonged to 16 and 5 genotypes, respectively, with CC/ST8-MRSA-IV, CC/ST30-MRSA-IV, CC/ST80-MRSA-IV, CC1/ST772-MRSA-V, CC30-MSSA, CC22-MSSA, and CC121-MSSA predominating. Temporal shifts in the predominant pvl-positive MRSA genotypes and a 6-fold increase in multiresistant pvl-positive MRSA genotypes occurred during the study period. An analysis of patient data indicated that pvl-positive S. aureus strains, especially MRSA strains, had been imported into Ireland several times. Two hospital and six family clusters of pvl-positive MRSA were identified, and 70% of the patient isolates for which information was available were from patients in the community. This study highlights the increased burden and changing molecular epidemiology of pvl-positive S. aureus in Ireland over the last decade and the contribution of international travel to the influx of genetically diverse pvl-positive S. aureus isolates into Ireland.