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

Abstract

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.

Multidrug‐resistant enterotoxigenicStaphylococcus aureuslineages isolated from animals, their carcasses, the personnel, and the environment of an abattoir in Greece

“…However, our MDR isolates did not belong only to ST398, but also to ST5, ST15, ST109, ST149, ST88, and ST80 clones. The wide spread of ST80 clone including strains resistant to kanamycin, tetracycline, and fusidic acid, has already been reported for human MRSA isolates in Greece (Drougka et al, ). MRSA showed higher resistance rates to most antimicrobials tested as compared to MSSA, except for fusidic acid (Figure ).…”

“…Twenty‐five out of 46 strains (54.35%) of this collection belonged to S. aureus clones of human origin. ST80 is a well‐known regional community‐ and hospital‐associated PVL‐positive MRSA clone in Greece (Drougka et al, ). Although the predominant clone in this study was ST80 (12 strains), however, it included only MSSA strains mainly PVL‐negative, originating from equipment, whereas, only two strains were recovered from personnel and carcasses.…”

Emergence of a Staphylococcus aureus Clone Resistant to Mupirocin and Fusidic Acid Carrying Exotoxin Genes and Causing Mainly Skin Infections

“…Humidity and close contact of uncovered skin between individuals, as well as intimate contact with the environment, favor the dissemination of S. aureus after skin damage (6,19). Disruption of the skin barrier due to minor injuries or insect bites, which are more common in the warm months, reveals the fibronectin receptors, through which the staphylococcal invasion of epithelial cells is mediated by fibronectin binding proteins (20).…”

“…This phenotype coexisted with resistance to fusidic acid (FA). The latter is not uncommon, since resistance to FA has been mainly associated with the predominance of the community-acquired (CA) MRSA ST80 European clone in many countries, including Greece, over the past 15 years (6,7). This clone is characterized by concurrent resistance to kanamycin, fusidic acid, and tetracycline.…”

Co-colonization by multidrug-resistant bacteria in two Greek intensive care units

“…KPC-Kp is now disseminated worldwide, posing as a major health problem for most healthcare systems. Vancomycin-resistant enterococci (VRE) and methicillinresistant Staphylococcus aureus (MRSA) were endemic in the Greek healthcare system from the beginning of the previous decade; however, their rate diminished during the last several years [3,4].…”