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Joseph Papaparaskevas

Publications and source records attributed to Joseph Papaparaskevas.

11 recordsLinked to original sources
PubMed2007

Differences in the evolution of imipenem susceptibility among Klebsiella pneumoniae and Escherichia coli isolates during a 6-year period in a tertiary care hospital.

The evolution of imipenem disk-diffusion susceptibility results of 2652 strains of Klebsiella pneumoniae and 7596 Escherichia coli isolated during the period 2000-2005 were analysed. Screening for production of metallo-beta-lactamases was performed using the EDTA-synergy method. The percentage rate of K. pneumoniae isolates having a zone diameter < or =25 mm increased from 20% in 2000 to 41% in 2005, whereas the respective rate of isolates having a zone diameter > or =30 mm decreased from 48 to 23%. These changes were more evident during 2000-2002, followed in 2003 by the isolation of the first imipenem-resistant strains. Regarding E. coli, a similar decrease was observed (the rates of isolates having a zone diameter < or =25 mm and > or =30 mm changed from 7% and 68% in 2000, to 32% and 36% in 2005, respectively) following the respective changes of K. pneumoniae. A total of 20 K. pneumoniae strains, but no E. coli, were confirmed as metallo-beta-lactamase producers. In conclusion, a decrease of the imipenem susceptibility prior to the isolation of the first resistant strains in a tertiary care hospital was detected, as well as differences in this decrease between the two species. These findings indicate that monitoring of the evolution of imipenem susceptibility in real-time may help in unveiling forthcoming resistance and in implementing the appropriate diagnostic techniques.

Anti-Bacterial Agents↗
PubMed2007

Differences in the changes in resistance patterns to third- and fourth-generation cephalosporins and piperacillin/tazobactam among Klebsiella pneumoniae and Escherichia coli clinical isolates following a restriction policy in a Greek tertiary care hospital.

The aim of the present study was to investigate whether replacement of broad-spectrum cephalosporins (CEPs) by piperacillin/tazobactam (TZP) as first-line empirical therapy may have an effect on beta-lactam resistance among Klebsiella pneumoniae and Escherichia coli in a tertiary care hospital. Data regarding CEP and TZP consumption and resistance were collected on a bimonthly basis during an open-label 2-year (1 year observational and 1 year interventional) study. Consumption of ceftazidime was reduced by 64.5%. In contrast, consumption of the other third-generation CEPs (cefotaxime and ceftriaxone) remained almost stable, whereas an increase in consumption of TZP by 2.8-fold was observed. A significant decrease in resistance to third-generation cephalosporins among K. pneumoniae isolates was observed, and the incidence of extended-spectrum beta-lactamase-producing isolates was notably reduced. These findings were less evident among E. coli isolates. Despite the significant increase in TZP consumption, the respective resistance rates of both bacterial species examined have remained almost unchanged.

Anti-Bacterial Agents↗
PubMed2006

In vitro activities of tigecycline against recently isolated Gram-negative anaerobic bacteria in Greece, including metronidazole-resistant strains.

The in vitro activity of tigecycline was compared with those of benzylpenicillin, piperacillin + tazobactam, cefoxitin, imipenem, metronidazole, clindamycin, and tetracycline against 249 Gram-negative anaerobic bacteria (158 Bacteroides fragilis group, 27 non-fragilis Bacteroides spp., 44 Prevotella spp., and 20 miscellaneous), recently isolated from 8 general hospitals in Athens, Greece. Overall tigecycline MIC(50) and MIC(90) were 0.25 and 2 mg/L, respectively, whereas B. fragilis group MIC(50) and MIC(90) were 0.5 and 4 mg/L, respectively. In total, 93% of the isolates were susceptible to tigecycline (MIC </= 4 mg/L) and no high-level resistance (MIC >/= 32 mg/L) was detected. In addition, tigecycline exhibited good activity against metronidazole- and tetracycline-resistant isolates (MIC(90), 0.5 and 8 mg/L, respectively). In summary, tigecycline exhibits good in vitro activity against Gram-negative anaerobic bacteria isolated in Greece, as well as stability to the most common occurring resistance mechanisms, attributes that make this parenteral agent an attractive alternative for use against infections involving these microorganisms.

Anti-Bacterial Agents↗
PubMed2006

Two cases of infections due to multidrug-resistant Bacteroides fragilis group strains.

Bacteroides fragilis group strains are still considered susceptible to most antimicrobial agents used for the treatment of infections caused by anaerobic organisms. We describe two cases of infections due to isolates simultaneously resistant to clindamycin, tetracycline, cefoxitin, piperacillin-tazobactam, and imipenem and, in one of the two cases, to metronidazole. Such infections, although still rare, do exist and tend to complicate treatment.

Aged↗
PubMed2004

Dissemination of vancomycin-resistant enterococci among haemodialysis patients in Athens, Greece.

OBJECTIVES: Vancomycin-resistant enterococci (VRE) may colonize haemodialysis patients, but their epidemiology in this population is not well defined. Within the few last years, VRE strains have emerged and are increasingly isolated in the nosocomial environment in Greece, but colonization of dialysis patients has never been evaluated before. This study sought to determine the epidemiology of VRE colonization within this high-risk population and define the risk factors. MATERIALS AND METHODS: During a 4 month period, rectal swabs or faecal specimens were collected from 334 consecutive outpatients, who were treated at four independent dialysis units located in the same area of Athens and referring patients to the same local hospital. The relatedness of isolates was defined by molecular typing, and demographic and clinical patient data were recorded. RESULTS: Thirteen multiresistant Enterococcus faecium vanA strains were isolated corresponding to a colonization frequency of 3.9%. They were separated into seven clusters: type A (two strains), type B (six strains) and types C to G (one strain each). Type B strains originated from three units, while a single unit demonstrated four type B and two type A strains. Univariate statistical analysis revealed that prior hospitalization (P=0.001), prior administration of antimicrobials (P=0.026) and male gender (P=0.019) were associated with VRE colonization. CONCLUSIONS: In Greece, haemodialysis patients are colonized with VRE at a low frequency. The predominance of one clone and its isolation from several units strongly indicate interfacility transmission of strains, most probably within a health care environment shared by all patients.

Aged↗
PubMed2004

Ruling out Bacillus anthracis.

Optimization of methods for ruling out Bacillus anthracis leads to increased yields, faster turnaround times, and a lighter workload. We used 72 environmental non-B. anthracis bacilli to validate methods for ruling out B. anthracis. Most effective were the use of horse blood agar, motility testing after isolates had a 2-h incubation in trypticase soy broth, and screening isolates with a B. anthracis-selective agar.

Animals↗
PubMed2003

Prevalence and characterization of the mechanisms of macrolide, lincosamide and streptogramin resistance in viridans group streptococci.

The presence of erm genes conferring constitutive and inducible resistance, as well as that of the mefA gene conferring only constitutive resistance, was investigated using PCR in 70 erythromycin resistant (MIC>or=1 mg/l) strains of viridans group streptococci (VGS) (18 Streptococcus mitis biotype 1, 16 S. mitis biotype 2, 15 S. oralis, 12 S. salivarius and nine S. sanguis) isolated from the oropharynx of healthy Greek children. All of the 56 isolates belonging to resistance phenotype M harbored the mefA gene. All of the 14 isolates constitutively resistant to macrolides and lincosamides (phenotype CR) harbored the ermB gene. Co-presence of both genes was not observed, whereas class A erm gene (previously known as ermTR) was not detected. Our results are consistent with a possible role of VGS as a reservoir of resistance genes now prevalent in pathogenic species of streptococci.

Anti-Bacterial Agents↗
PubMed2003

Changes in the epidemiology of methicillin-resistant Staphylococcus aureus in a Greek tertiary care hospital, over an 8-year-period.

A total of 1019 non-replicate, consecutively isolated methicillin-resistant Staphylococcus aureus (MRSA) strains were collected from in-patients of a tertiary care general hospital in Athens, Greece, during the period 1994-2001. The susceptibility, resistance phenotypes and the dissemination of these isolates among hospital wards were studied. Total MRSA and gentamicin-resistant MRSA, as a proportion of the S. aureus isolates, increased from 33 and 9% in 1994 to 50.1 and 33.3% in 2001, respectively. Three main multi-resistant phenotypes predominated, representing 50.9% of the total MRSA isolates in 2001. MRSA strains susceptible to all antibiotics tested decreased to 1.9% in 1997 and again increased to 13.5% in 2001. A gradual decrease in the susceptibility of vancomycin during the 8-year-period was detected, but no vancomycin resistant S. aureus strains were isolated.

Cross Infection↗
PubMed2002

Epidemiology of multiresistant Enterococcus avium isolates in a Greek tertiary care hospital.

A retrospective survey of the isolation rate of Enterococcus avium during the period March 1994-February 2000 conducted in Laikon General Hospital using the WHONET software, revealed a peak in the isolation rates of this species during March 1995-February 1996. The ten strains isolated during this time were studied further. No glycopeptide resistance was detected but resistance to ampicillin, ciprofloxacin, erythromycin, gentamicin (high-level) and streptomycin (high-level) was present in nine, ten, nine, three and seven of the isolates, respectively. The genes aac(6')-Ie+aph(2")-Ia and ant(6)-I, encoding for high-level gentamicin and streptomycin resistance, respectively, were detected only in the isolates with the corresponding phenotypes. Beta-lactamase production and haemolysis were not detected. There was evidence of ward-, floor- and building-specific distribution among the different aminoglycoside resistance phenotypes. DNA fingerprinting by PFGE grouped six of the ten isolates in a single cluster with 83% similarity, even though they expressed various resistance phenotypes. These results suggest dissemination of resistance genes among both genetically related and unrelated strains.

Anti-Bacterial Agents↗