VIM-1 Metallo-β-lactamase in Acinetobacter baumannii

In 2004 and 2005, 5 metallo-β-lactamase (MBL)-positive Acinetobacter baumannii isolates were found in 2 Greek hospitals. Isolates were unrelated and carried blaVIM-1 in a class 1 integron; blaOXA-51- and blaOXA-58-like carbapenemase genes were also detected. VIM-1 MBL in Acinetobacter spp. causes concern, given the increasing resistance of this species

Novel Variant (bla(VIM-4)) of the Metallo-β-Lactamase Gene bla(VIM-1) in a Clinical Strain of Pseudomonas aeruginosa

A Pseudomonas aeruginosa isolate highly resistant to carbapenems was collected from a patient with postsurgical cerebrospinal infection in Greece. The isolate carried a class 1 integron that contained as a sole cassette the gene bla(VIM-4), a novel variant of bla(VIM-1), with one nucleotide difference resulting in a Ser-to-Arg change at amino acid position 175 of the VIM-1 enzyme. This is the first detection of a VIM-1 variant after its appearance in Italy

Nosocomial Spread of an Unusual Methicillin-Resistant Staphylococcus aureus Clone That Is Sensitive to All Non-β-Lactam Antibiotics, Including Tobramycin

Between January and December 1999, in Hippokration General Hospital, Thessaloniki, Greece, a large proportion of the methicillin-resistant Staphylococcus aureus isolates (34.4%) exhibited susceptibility to virtually all alternative non-β-lactam antibiotics, including tobramycin. Twenty-five of them were selected randomly for further testing; all belonged to a unique genotype and were characterized as heterogeneously resistant to oxacillin. The aadD gene, encoding tobramycin resistance, failed to be amplified in all cases, indicating absence of the gene or the entire plasmid pUB110 from the mec DNA

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. Mutant subpopulations of all four isolates had at least fourfold higher minimum inhibitory concentrations than those of native cells for imipenem and meropenem. The heterogeneous subpopulations, when compared with the respective native ones, had significantly increased transcription levels of the mexB and mexY genes (P < 0.05), whereas transcription levels of the mexE gene remained unchanged. They also exhibited significantly decreased expression of the oprD gene (P < 0.05) and decreased intensity of the protein band of the porin OprD. Upregulation of efflux systems, in part, and the decrease of OprD contribute to the heterogeneous growth against carbapenems in our P. aeruginosa clinical isolates

Dissemination of Clonally Unrelated Erythromycin- and Glycopeptide-Resistant Enterococcus faecium Isolates in a Tertiary Greek Hospital

Between September 1999 to February 2001, 25 glycopeptide-resistant Enterococcus faecium (GRE) isolates were recovered from a Greek hospital. The isolates exhibited 13 distinct chromosomal macrorestriction types by pulsed-field gel electrophoresis, and all were erythromycin and vancomycin resistant, carrying the genes vanA and ermB. Vancomycin resistance, always linked with erythromycin resistance, was transferable from 17 isolates. The dissemination of erythromycin-resistant GRE strains may, at least in part, reflect the extensive use of macrolides in husbandry in Greece

Outbreak of Infections Caused by Enterobacter cloacae Producing the Integron-Associated β-Lactamase IBC-1 in a Neonatal Intensive Care Unit of a Greek Hospital

Nineteen of 27 ceftazidime-resistant Enterobacter cloacae isolates from a neonatal intensive care unit in Thessaloniki, Greece, had genes coding for the novel extended-spectrum β-lactamase IBC-1; 18 of those 19 harbored similar conjugative plasmids and belonged to two distinct genetic lineages. A synergy test with ceftazidime and imipenem enabled us to identify five unrelated bla(IBC-1)-carrying E. cloacae isolates from other wards of the hospital. It seems that this integron-associated gene is capable of dispersing both by clonal spread and by gene dissemination

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 μg/ml were tested for oxacillin efficiency by population analyses and experimental thigh infections. These isolates harbored staphylococcal cassette chromosome mec type IV and belonged to two genotypes. Two of the four isolates were found by population analysis to be truly oxacillin susceptible. All four isolates exhibited significant reductions in the numbers of colonies grown after dicloxacillin treatment of experimental thigh infections, as also did a mecA-negative S. aureus control strain. These observations indicate that some of the phenotypically oxacillin susceptible mecA-positive Staphylococcus aureus isolates may be at least partially responsive to oxacillin

Pulmonary Function and Circulating Adhesion Molecules in Patients with Diabetes Mellitus

BACKGROUND: Lung function in diabetes has been reported in several studies with contradictory results. Diabetes mellitus increases expression of adhesion molecules through hyperglycemia. These molecules play an important role in the pathophysiological dysfunction of the vasculature