A patient with respiratory toxigenic diphtheria in Greece after more than 30 years.

The introduction of treatment and systematic vaccination has significantly reduced diphtheria mortality; however, toxigenic strains continue to circulate worldwide. The emergence of an indigenous diphtheria case with fatal outcome in Greece, after 30 years, raised challenges for laboratory confirmation, clinical and public health management. Toxigenic Corynebacterium diphtheriae was isolated from an incompletely vaccinated 8-year-old boy with underlying conditions. The child passed away due to respiratory distress syndrome, before the administration of diphtheria antitoxin (DAT). All close contacts in family, school and hospital settings were investigated. Pharyngeal swabs were obtained to determine asymptomatic carriage. Chemoprophylaxis was given for 7 days to all close contacts and a booster dose to those incompletely vaccinated. Testing revealed a classmate, belonging to a subpopulation group (Roma), and incompletely vaccinated, as an asymptomatic carrier with an indistinguishable toxigenic strain (same novel multilocus sequence type, designated ST698). This case highlights the role of asymptomatic carriage, as the entry of toxigenic strains into susceptible populations can put individuals and their environment at risk. Maintenance of high-level epidemiological and microbiological surveillance, implementation of systematic vaccination in children and adults with primary and booster doses, availability of a DAT stockpile, and allowing timely administration are the cornerstone to prevent similar incidents in the future.

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.

A 12-year survey of methicillin-resistant Staphylococcus aureus infections in Greece: ST80-IV epidemic?

Methicillin-resistant Staphylococcus aureus (MRSA) is an important cause of both healthcare-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA) infections. Severe MRSA infections have been associated with the virulence factor Panton-Valentine leukocidin (PVL). The aim of this study was to investigate susceptibility patterns, the presence of toxin genes, including that encoding PVL, and clonality among MRSA isolates collected from patients in Greece over a 12-year period. MRSA isolates were collected from January 2001 to December 2012 from six different hospitals. Antibiotic susceptibility was determined with the disk diffusion method and the Etest. The presence of the toxic shock syndrome toxin-1 gene (tst), the enterotoxin gene cluster (egc) and the PVL gene was tested with PCR. The genotypic characteristics of the strains were analysed by SCCmec and agr typing, and clonality was determined with pulsed-field gel electrophoresis and multilocus sequence typing. An increasing rate of MRSA among S. aureus infections was detected up to 2008. The majority of PVL-positive MRSA isolates belonged to a single clone, sequence type (ST)80-IV, which was disseminated both in the community and in hospitals, especially during the warmest months of the year. Carriage of tst was associated with ST30-IV, whereas egc was distributed in different clones. CA-MRSA isolates were recovered mainly from skin and soft tissue infections, whereas HA-MRSA isolates were associated with surgical and wound infections. During the period 2001-2012, ST80-IV predominated in the community and infiltrated the hospital settings in Greece, successfully replacing other PVL-positive clones. The predominance of ST239-III in HA-MRSA infections was constant, whereas new clones have also emerged. Polyclonality was statistically significantly higher among CA-MRSA isolates and isolates from adult patients.