A newly described vancomycin-resistant ST412 Enterococcus faecium predominant in Greek hospitals.

A total of 359 vancomycin-resistant enterococci (344 Enterococcus faecium and 15 E. faecalis) collected during 2007 from eight tertiary-care hospitals in Greece were analysed for genotypic characteristics. Four common clones, ST412, ST203, ST16 and ST17, were identified among E. faecium and one clone, ST28, among E. faecalis strains.

In vitro activity of daptomycin against Gram-positive cocci: the first multicentre study in Greece.

A total of 10420 Gram-positive cocci (including staphylococci, enterococci and various groups of streptococci) collected from clinically significant specimens in ten Greek hospitals during 2006--2007 were tested for their susceptibility to daptomycin. The minimum inhibitory concentration (MIC) was determined by the broth microdilution method. Daptomycin demonstrated very high activity against Enterococcus faecalis (MIC at which 50% of the isolates were inhibited (MIC50) = 1mg/L and MIC at which 90% of the isolates were inhibited (MIC90) = 1.36 mg/L), Enterococcus faecium (MIC50 = 1.36 mg/L and MIC90 = 1.90 mg/L), Streptococcus pyogenes (MIC50 = 0.12 mg/L and MIC90 = 0.50mg/L), Streptococcus agalactiae (MIC50 = 0.09 mg/L and MIC90 = 0.12 mg/L), Streptococcus pneumoniae (MIC50 = 0.24 mg/L and MIC90 = 0.5 mg/L) and viridans group streptococci (MIC50 = 0.50 mg/L and MIC90 = 0.89 mg/L). Resistance to linezolid and vancomycin for enterococci and to penicillin for streptococci appears to be independent of reduced susceptibility to daptomycin. On the other hand, daptomycin was also active against meticillin-resistant Staphylococcus aureus (MIC50 = 0.44 mg/L and MIC90 = 0.78 mg/L) and meticillin-resistant coagulase-negative staphylococci (MIC50 = 0.24 mg/L and MIC90 = 0.44 mg/L); however, 0.9% of the staphylococci tested had an MIC > 1mg/L, which is the Clinical and Laboratory Standards Institute breakpoint proposed for susceptibility. For all tested organism groups, resistance to daptomycin was not associated with glycopeptide resistance.

Clonal dissemination of mupirocin-resistant staphylococci in Greek hospitals.

OBJECTIVES: To determine the rates of mupirocin resistance in staphylococci during a 4 year period (1999-2002) in Greece. MATERIALS: A total of 1200 Staphylococcus aureus and 2760 coagulase-negative staphylococci (CoNS), consecutively collected from four Greek hospitals located in different geographical areas, were tested for susceptibility to mupirocin using the Etest and a reference agar dilution method. RESULTS: Twenty-four S. aureus (2%) and 532 CoNS (19.2%) were found to be mupirocin-resistant during the study period. High-level mupirocin resistance was detected in 20 S. aureus (1.6%) and in 440 CoNS (15.9%), respectively. No variations in the rates of mupirocin-resistant S. aureus in relation to the year of collection were observed. In contrast, the rate of mupirocin-resistant CoNS increased dramatically from 9% in 1999, to 14% in 2000, 20% in 2001 and reached 33% in 2002. PFGE analysis revealed the presence of one main clone (A) among mupirocin-resistant S. aureus and two main clones (i and a) among Staphylococcus epidermidis isolates. CONCLUSIONS: In Greece, the rate of mupirocin-resistant S. aureus has remained low and steady since 1999. The high rate of mupirocin-resistant CoNS (33%) in 2002 was due mainly to clonal dissemination of epidemic hospital clones.

Colistin for Klebsiella pneumoniae-associated sepsis.

Klebsiella pneumoniae that was resistant to all available antibiotics (minimum inhibitory concentration of imipenem, 32 microg/mL), including carbapenems, was isolated from blood samples obtained from a 48-year-old patient in the intensive care unit. The patient developed septic shock, which was successfully treated with colistin, the only antibiotic with activity against this multidrug-resistant strain.

VIM-1 Metallo-beta-lactamase-producing Klebsiella pneumoniae strains in Greek hospitals.

Seventeen Klebsiella pneumoniae clinical isolates carrying the bla(VIM-1) metallo-beta-lactamase gene were collected in the intensive care units of three hospitals in Athens, Greece, in 2002. They exhibited various carbapenem resistance levels (Etest MICs of imipenem ranged from 4 to 32 microg/ml). All isolates gave positive results by the imipenem-EDTA synergy Etest. The isolates were classified into four main types by pulsed-field gel electrophoresis; the majority of the isolates (5 and 10 isolates) belonged to two types. The bla(VIM-1) gene cassette was part of the variable region of a class 1 integron that also included aac6, dhfrI, and aadA. This structure was carried by transferable plasmids.

Isolation rate, T-serotyping and susceptibility to antibiotics of Group A Streptococcus from pediatric infections in Athens.

OBJECTIVE: The epidemiology of Group A Streptococcus (GAS) in Greece is not known. We have therefore conducted this prospective study to investigate the isolation rate of GAS from pediatric specimens, determine T-serotype frequency and examine the susceptibility of GAS to penicillin, erythromycin and clindamycin. METHODS: Over a 3-year study-period (1993-95) 11 597 clinical specimens obtained from sick children were inoculated on appropriate culture media. The isolation and identification of GAS strains were assessed by conventional methods. T-typing was performed by slide agglutination. Serum opacity factor (OF) was detected by microwell METHOD: The susceptibility of the strains was tested by the Kirby Bauer method. RESULTS: GAS were isolated from 1125 out of 11 597 (9.7%) clinical specimens, mostly from throat samples (15.6%). T-serotyping was performed in 652 GAS strains. A significant difference of the incidence of T-serotypes was observed within the 3 years studied (chi2 = 70.3, DF = 18, P < 0.001). The most dominant isolates were T-1 (25%), T-4 (20%) and T-12 (16%) during 1993, 1994 and 1995, respectively. Non-typeable (NT) strains were 4%. OF and hyaluronic acid were produced from 49.8% and 3% of the strains, respectively. All isolated strains were susceptible to penicillin and clindamycin. Resistance to erythromycin was 5.0-8.7% over the 3-year study period. CONCLUSIONS: There was a wide distribution of GAS T-serotypes in Athens and a significant change in their annual predominance. All strains were susceptible to penicillin and clindamycin, but a low level of erythromycin resistance was observed.

A three-day octreotide-containing helicobacter pylori eradication therapy for cure of peptic ulcers.

BACKGROUND/AIMS: Octreotide is used to arrest peptic ulcer hemorrhage. Since it has anti-secretory properties, it could also be used in Helicobacter pylori eradication therapy, to cure peptic ulcer before discharging patients from hospital. The aim of this pilot study was to determine safety and efficacy of an ultra short quadruple octreotide containing H. pylori eradication therapy in patients with peptic ulcer. METHODOLOGY: Twenty-six consecutive symptomatic H. pylori-positive patients with duodenal (n = 20) or gastric ulcer (n = 6), were treated with a three-day course of octreotide 0.3 mg/day subcutaneously, amoxicillin plus metronidazole 2 g/day orally and colloid bismuth subcitrate 480 mg/day. CLO-test, culture and crush tissue smears were performed on admission to the study, at 4 and 8 weeks post treatment. The effect of octreotide on intragastric pH (n = 10) was also investigated. RESULTS: Octreotide significantly increased the mean 24-hour intragastric pH > 3 over 68.9% of the time (37.1%-99.5%). There were no treatment side effects. Ulcer pain was abolished at between 2-12 days. By intention-to-treat 24/26(92.3%, 95% CI 82%-100%) ulcers had healed at 4 weeks. H. pylori eradication rate at 8 weeks was 88.5% (23/26) (95% CI 76%-100%). CONCLUSIONS: Our ultra-short octreotide containing quadruple therapy is a safe and effective regime in eradicating H. pylori and healing peptic ulcers. It may be a suitable therapy for hospitalized patients with peptic ulcer hemorrhage.

Indications of in vivo transfer of an epidemic R plasmid from Salmonella enteritidis to Escherichia coli of the normal human gut flora.

The presence of conjugative R plasmids as well as the possible similarities among them were studied in nine ampicillin-resistant Salmonella enteritidis isolates and nine ampicillin-resistant Escherichia coli isolates from the normal fecal flora that were simultaneously isolated from nine epidemiologically unrelated outpatients. It was found that in eight patients, ampicillin resistance in S. enteritidis was encoded by ca. 34-MDa transferable plasmids very similar to those found in a recent study of the epidemiology of ampicillin-resistant S. enteritidis in Greece (A.C. Vatopoulos, E. Mainas, E. Balis, E.J. Threlfall, M. Kanelopoulou, V. Kalapothaki, H. Malamou-Lada, and N.J. Legakis, J. Clin. Microbiol. 32:1322-1325, 1994). Moreover, transferable R plasmids with the same molecular size and restriction pattern were found in the normal flora E. coli of two of these patients. This finding, if confirmed by further studies, is consistent with the hypothesis that normal flora E. coli could act as a reservoir of resistant genes and, consequently, as a factor in the dissemination of these genes among pathogens of human and animal origin such as Salmonella spp. and needs to be examined further.

Molecular epidemiology of ampicillin-resistant clinical isolates of Salmonella enteritidis.

During the last 6 years in Greece, there has been a significant increase in the number of ampicillin-resistant Salmonella clinical isolates reported. In this study 23 ampicillin-resistant Salmonella strains, consecutively isolated from patients with epidemiologically unrelated cases of food poisoning, were investigated. By serotyping and phage typing, 21 of these strains were identified as Salmonella enteritidis phage type 6a, 1 was identified as Salmonella typhimurium, and 1 was identified as Salmonella saintpaul. By plasmid pattern analysis, the 21 S. enteritidis strains were further differentiated into five groups. Group I consisted of 5 strains (carrying two plasmids of ca. 38 and 34 MDa), group II consisted of 10 strains (three plasmids of ca. 38, 34, and 2.5 MDa), group III consisted of 3 strains (four plasmids of ca. 38, 34, 15, and 2.5 MDa), group IV consisted of 1 strain (five plasmids of ca. 100, 38, 34, 24, and 15 MDa), and group V consisted of 2 strains (three plasmids of ca. 100, 38, and 24 MDa). Ampicillin resistance was easily transferred to Escherichia coli and was associated with the transfer of the 34-MDa plasmid, classified in the N incompatibility group for all strains of groups I to IV, and with the transfer of the 100-MDa plasmid for the group V strains. EcoRI restriction endonuclease digestions showed an extensive homology among the 34-MDa conjugative R plasmids. Hybridizations of the EcoRI restriction fragments of the 34-MDa plasmids with a TEM-type probe revealed the locus of the beta-lactamase gene to be situated on a ca. 6.6-MDa fragment, common in all plasmids. These results indicate that ampicillin resistance in Greece is due to the spread of a limited number of clones of S. enteritidis phage type 6A, carrying related 34-MDa R plasmids. Work is in progress to obtain a better understanding of ampicillin resistance in S. enteritidis.