Differences in biofilm formation and virulence factors between clinical and fecal enterococcal isolates of human and animal origin.

The present study investigated the possible correlation between carriage of the virulence genes esp and fsrb, production of hemolysin and gelatinase and biofilm formation in human vs. animal enterococcal isolates. A collection of 219 enterococcal isolates recovered from clinical and fecal surveillance samples of hospitalized patients and 132 isolates from animal feces were studied.

Prevalence of pediculosis capitis among schoolchildren in Greece and risk factors: a questionnaire survey.

Pediculosis capitis is a common problem worldwide. The aim of this study was to estimate the prevalence of pediculosis capitis in children of preschool or school age in Greece, as well as to investigate the potential risk factors. The study included children of preschool and school age from all over Greece, including urban, semi-urban, and rural areas of Greece.

Association of biofilm formation and methicillin-resistance with accessory gene regulator (agr) loci in Greek Staphylococcus aureus clones.

Pathogenicity of Staphylococcus aureus is coordinated by the accessory gene regulator (agr) system. Previous studies suggested that agr Group II methicillin-resistant S. aureus (MRSA), a polymorphism that has been associated with moderate response to vancomycin, may also be related with overproduction of biofilm.

Clonal spread of KPC-2 carbapenemase-producing Klebsiella pneumoniae strains in Greece.

Objectives: KPC-possessing Klebsiella pneumoniae have been found to be widespread in several regions but are still rarely detected in Europe. We describe the characteristics of an outbreak caused by KPC producers in a tertiary care Greek hospital.

Methods: During a 12 month period (October 2007-September 2008), 47 patients in Hippokration University Hospital yielded K.

In vitro and in vivo evaluations of oxacillin efficiency against mecA-positive oxacillin-susceptible Staphylococcus aureus.

Community-type Staphylococcus aureus strains that are positive for mecA and PBP2a but appear phenotypically susceptible to oxacillin are increasingly reported worldwide. Four S. aureus clinical isolates carrying the mecA gene with oxacillin MICs of <2 microg/ml were tested for oxacillin efficiency by population analyses and experimental thigh infections.

Novel model for studying hematogenous infection in an experimental setting of implant-related infection by a community-acquired methicillin-resistant S. aureus strain.

The aim of this study is to establish a new experimental model of hematogenous implant-related infection (IRI) by a community-acquired methicillin-resistant S. aureus (CA-MRSA) strain. Cylindrical porous tantalum intramedullary implants were inserted in the proximal right tibia of 30 male white rabbits after administration of antibiotic prophylaxis.

Efflux system overexpression and decreased OprD contribute to the carbapenem heterogeneity in Pseudomonas aeruginosa.

Pseudomonas aeruginosa strains exhibiting a heterogeneous mode of growth against carbapenems have been described recently. This study investigated the underlying molecular mechanisms in four genetically unrelated P. aeruginosa clinical isolates that were previously characterized by population analyses as heterogeneously resistant against carbapenems.

Hidden VIM-1 metallo-beta-lactamase phenotypes among Acinetobacter baumannii clinical isolates.

A total of 87 Acinetobacter baumannii nonrepetitive consecutive clinical isolates were tested for the presence of metallo-beta-lactamases (MBLs). Results of phenotypic assays (MBL Etest, imipenem/imipenem-EDTA combined-disk test, and imipenem/EDTA double-disk synergy test) were negative in all cases, but molecular testing revealed the presence of two bla(VIM-1)-carrying isolates. One isolate had bla(VIM-1) preceded by a weak P1 promoter, and both had inactivated P2 promoters and reduced bla(VIM-1) expression, partially justifying the results revealing hidden MBL phenotypes.

Molecular cloning and biochemical characterization of VIM-12, a novel hybrid VIM-1/VIM-2 metallo-beta-lactamase from a Klebsiella pneumoniae clinical isolate, reveal atypical substrate specificity.

Metallo-beta-lactamases (MBLs) are considered an emerging family of Zn2+-dependent enzymes that significantly contribute to the resistance of many nosocomial pathogens against beta-lactam antimicrobials. Since these plasmid-encoded enzymes constitute specific molecular targets for beta-lactams, their exact mode of action is greatly important in deploying efficient anti-infective treatments and for the control of severe multi-resistant nosocomial infections, which becomes a global problem. A novel hybrid VIM-1/VIM-2-type beta-lactamase (named VIM-12) has recently been identified in a clinical isolate of Klebsiella pneumoniae in Greece.

A highly carbapenem-resistant Pseudomonas aeruginosa isolate with a novel blaVIM-4/blaP1b integron overexpresses two efflux pumps and lacks OprD.

Objectives: A Pseudomonas aeruginosa clinical isolate that exhibited high-level carbapenem resistance and produced metallo-beta-lactamase (MBL) was recovered from a Greek patient. This study was conducted to determine the underlying mechanisms that conferred the carbapenem resistance phenotype.

Methods: MICs were determined by Etest and Etest MBL.

Characterization of clinical isolates of Pseudomonas aeruginosa heterogeneously resistant to carbapenems.

Fourteen apparently carbapenem-susceptible Pseudomonas aeruginosa clinical isolates that exhibited colonies within the inhibition zone around carbapenem discs were analysed. MICs of carbapenems were determined and the isolates were genotyped by PFGE. Population analysis, one-step selection of carbapenem-resistant mutants and growth curves of progenitors and carbapenem-resistant subpopulations were performed.

Combination of staphylococcal chromosome cassette SCCmec type V and Panton-Valentine leukocidin genes in a methicillin-resistant Staphylococcus aureus that caused necrotizing pneumonia in Greece.

We describe a case of necrotizing pneumonia in Greece caused by a community-acquired methicillin-resistant Staphylococcus aureus (MRSA) producing Panton-Valentine leukocidin (PVL) carrying the staphylococcal chromosome cassette mec (SCCmec) type V. The pulse field gel electrophoresis (PFGE) pattern of this strain differed significantly from the PVL-positive multi-locus sequence typing (MLST)-80 clone of MRSA, which predominates in Greece and in Europe. Further analysis of this strain revealed that it belonged to the agr1 allele type, and its resistance to tobramycin, gentamicin, and kanamycin was associated to the presence of aac-(6')-Ie+aph(2') gene.

VIM-1 metallo-beta-lactamase in Acinetobacter baumannii.

In 2004 and 2005, 5 metallo-beta-lactamase (MBL)-positive Acinetobacter baumannii isolates were found in 2 Greek hospitals. Isolates were unrelated and carried blaVIM-1 in a class 1 integron; bla(OXA-51-) and bla(OXA-58-like) carbapenemase genes were also detected. VIM-1 MBL in Acinetobacter spp.

Novel serum inflammatory markers in patients with adnexal mass who had surgery for ovarian torsion.

Objective: To determine the diagnostic value of preoperative levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8), and E-selectin in patients with an adnexal mass who had surgery for ovarian torsion.

Design: Prospective study.

Setting: University hospital.

Detection of a novel variant bla(CTX-M-3) extended spectrum beta-lactamase gene in a community-acquired Escherichia coli isolate.

A highly cefotaxime- and cefepime-resistant but ceftazidime-sensitive Escherichia coli isolate was recovered from a community-acquired urinary infection of a Greek patient. Susceptibility testing, transfer assays, plasmid analysis as well as PCR and sequencing techniques were used to investigate the underlying mechanism of resistance. The isolate carried a new variant of the bla(CTX-M-3) gene that possessed a T instead of A at nt position 663.

Antimicrobial susceptibility of Neisseria gonorrhoeae in Greece: data for the years 1994-2004.

Objectives: Surveillance data concerning antimicrobial susceptibilities of Neisseria gonorrhoeae isolated in Greece during the 11 year period 1994-2004 are presented.

Methods: Antimicrobial susceptibilities of all gonococcal isolates received by the Greek National Reference Center for N. gonorrhoeae during the study period were determined in terms of MICs using Etest.

VIM-12, a novel plasmid-mediated metallo-beta-lactamase from Klebsiella pneumoniae that resembles a VIM-1/VIM-2 hybrid.

A transferable plasmid from Klebsiella pneumoniae carried a class 1 integron containing bla(VIM-12), a novel bla(VIM)-type gene, flanked by two copies of aacA7. bla(VIM-12) was clustered between bla(VIM-1) and bla(VIM-2) and differed from bla(VIM-1) by 18 nucleotides that were all located at the 3' end and matched the corresponding nucleotides in bla(VIM-2). The bla(VIM-12)-associated 59-base element was identical to that described in bla(VIM-2) alleles.

ICAM-1, ICAM-2 and ICAM-3 in the sera of patients with idiopathic pulmonary fibrosis.

In order to test the serum levels of ICAM-1, ICAM-2 and ICAM-3 in patients with idiopathic pulmonary fibrosis (IPF), twenty patients with IPF and eleven with secondary interstitial fibrosis (SIF), as well as forty healthy volunteers (HV) were studied. Serum intracellular adhesion molecules (ICAM) 1, 2 and 3 were assessed by ELISA. Functional respiratory tests, which included spirometry and lung diffusing capacity were simultaneously performed.

Outbreaks in distinct regions due to a single Klebsiella pneumoniae clone carrying a bla VIM-1 metallo-{beta}-lactamase gene.

From December 2004 to March 2005, 27 Klebsiella pneumoniae clinical isolates that were positive by the imipenem-EDTA double-disk synergy test and that exhibited a single macro-restriction pattern were recovered in two distinct Greek hospitals. The isolates carried a transferable bla(VIM-1) metallo-beta-lactamase gene in a class 1 integron. Reverse transcriptase PCR showed that the gene was similarly expressed in low- and high-level carbapenem-resistant isolates, indicating the existence of additional resistance mechanisms.