[Management of in vitro diagnostic medical device batch identification in clinical microbiology laboratories]. / Rízení identifikace sarzí in vitro diagnostik v laboratori klinické mikrobiologie.

In Czech Republic, clinical microbiology laboratories are currently acredited in accordance with the ISO 15189 standard specifying requirements for quality management and tracing of diagnostic device batches used in individual (albeit partial) tests. At present, practically all laboratories are equiped with laboratory information systems containing detailed entries on all tests performed in processed samples. The article focuses on procedures and potential tools supporting the laboratory logistics of in vitro diagnostics with information systems to meet the requirements for tracing the utilized in vitro diagnostic devices related to the analyzed samples.

Prevalence of extended-spectrum beta-lactamase-positive Klebsiella pneumoniae isolates in the Czech Republic.

This study focused on the prevalence and molecular biology of extended-spectrum beta-lactamase (ESBL)-positive Klebsiella pneumoniae isolates collected in the Czech Republic. Clinical material from patients hospitalised in 16 Czech hospitals in September 2004 was used to isolate K. pneumoniae strains. Strains were identified by standard identification procedures. Susceptibility of the strains to antibiotics was tested using a microdilution method. The double-disk synergy test and combination disk method were used to determine ESBL production. Molecular biology characteristics of ESBL-positive isolates were determined using genomic DNA isolation, XbaI restriction digestion and pulsed-field gel electrophoresis differentiation. The acquired restriction maps of individual isolates were compared using GelCompar II software and their relationships were determined. During the 3-week period, 483 K. pneumoniae strains causing clinically detectable diseases were isolated. Of these, 117 (24.2%) were determined to be ESBL-positive. The prevalence of ESBL-positive isolates was 38.9% in Intensive Care Units (ICUs) and 13.1% in standard wards. More than 50% of ESBL-positive isolates were treated effectively only with meropenem (98%), cefoperazone/sulbactam (61%) and amikacin (54%). Conversely, ESBL-negative isolates showed high susceptibility to all tested antibiotics (76-99%). Molecular biology analysis identified 18 clonal types containing two to six identical isolates. Seventeen clones usually contained isolates from only one hospital; isolates from two hospitals were identified only in one clone. Based on the abovementioned results, the prevalence of ESBL-positive K. pneumoniae isolates in the Czech Republic can be perceived as relatively high, especially in ICUs. Extensive spread of 'epidemic clones' within Czech hospitals and, to a limited extent, between them can be demonstrated.

The occurrence of vancomycin-resistant enterococci in hematological patients in relation to antibiotic use.

Very important bacterial pathogens found in hematological patients at present are vancomycin-resistant enterococci (VRE). The main goal of this retrospective study was to assess their occurrence in relation to antibiotic use. We isolated 1918 Enterococcus strains, in toto, 138 (7.2%) of which proved to be VRE. The VRE most frequently identified were Enterococcus faecium VanA (77%) and Enterococcusfaecalis VanB (12%), mostly isolated from stools (57%). Comparing the development of the selection pressure of antibiotics and percentage of VRE in each period of observation, an effect of the administration of each antibiotic group on the occurrence of VRE can be presumed. A reduction in the administration of third generation cephalosporins, glycopeptides and fluoroquinolones and its replacement by penicillin antibiotics combined with inhibitors of bacterial beta-lactamases, contributed to the cessation of VRE incidence and succeeding reduced occurrence from 15.1% in the second half of 1998 to 6.1% in the first half of 2000.

Antibiotic selective pressure and development of bacterial resistance.

This study evaluates the development of resistance in Gram-negative rods to cefotaxime and ceftazidime, ofloxacin and ciprofloxacin, gentamicin and amikacin, meropenem and ampicillin/sulbactam over a five year period of use (1994-1998) at the University Hospital in Olomouc, Czech Republic. The development of bacterial resistance was linked with antibiotic use and hence selective pressure which was specific for the type of antibiotic and the bacterial species. Statistically significant correlations were found for the use of ofloxacin and resistance in Escherichia coli, Proteus vulgaris and Providencia rettgeri; cefotaxime and Enterobacter cloacae; ceftazidime and Acinetobacter spp., Enterobacter agglomerans and Proteus vulgaris; and gentamicin and Proteus mirabilis.

Development of bacterial resistance to the third generation cephalosporins and their clinical use.

Development of Gram-negative rods resistance to the third generation cephalosporins (cefotaxime, ceftazidime, cefoperazone) in connection with their application at the University Hospital in Olomouc was evaluated in this study. The highest increase in resistance to cefotaxime was detected in Enterobacter cloacae (from 22.9% in 1995 to 49.0% in 1997) and Enterobacter agglomerans strains (28.0% - 40.5%). In addition, increased resistance to ceftazidime in Acinetobacter baumannii (12.5% - 35.1%), Enterobacter aerogenes (7.4% - 20.9%), Enterobacter cloacae (16.7% - 47.2%) and Pseudomonas aeruginosa (4.0% - 26.3%) was observed. Finally, the greatest increase in frequency of strains resistant to cefoperazone was observed in E. aerogenes (18.4% - 30.1%), E. agglomerans (31.0% - 52.3%), E. cloacae (35.5% - 47.2%) and Providencia rettgeri (26.5% - 53.2%). A 23.5% increase in third generation cephalosporin use was evident by evaluation of RDDD(ATB) parameters in 1996 and 1997. Corresponding values for individual antibiotics were 26.5% cefotaxime, 20.7% ceftriaxone, and 40.3% ceftazidime increase. However, cefoperazone use decreased by 10.9%.

Implementation of a practical antibiotic policy in the Czech Republic.

We describe the antibiotic control policy at the Faculty Hospital in Olomouc, Czech Republic. Practical examples of successful implementation of the policy are provided.

Occurrence of vancomycin-resistant enterococci in relation to the administration of glycopeptide antibiotics.

Occurrence of vancomycin-resistant enterococci and its relationship to the administration of glycopeptide antibiotics (vancomycin, teicoplanin) was described. A total number of 628 strains of the genus Enterococcus was isolated in the Hemato-oncologic Department of the University Hospital in Olomouc in 1997. Seven strains (1.1%) were found to be resistant to vancomycin. Five of them were identified as Enterococcus faecalis of phenotype VanB, and two strains as E. faecium of phenotype VanA. The administration of vancomycin and teicoplanin in the Hemato-oncologic Department amounted to 85.7% and 89.2%, respectively, of the total consumption of these drugs at the University Hospital.

[Bacterial strains isolated from neutropenic patients and their resistance to antibiotics]. / Výskyt bakteriálních kmenu izolovaných u neutropenických pacientu a jejich rezistence k antibiotikum.

BACKGROUND: Although Gram negative as well as Gram positive bacteria participate in febrile episodes of neutropenic patients, in particular recently the ratio of Gram positive bacteria is increasing. The objective of the present work was to investigate the incidence and antibiotic resistance of pathogenic bacterial agents in neutropenic patients. METHODS AND RESULTS: The presence of bacteria was investigated in 446 neutropenic patients hospitalized at the Haematological Clinic in 1995. Haemocultures (apparatus Bact/Alert 120, cultivation media Organon-Teknika) and urine were examined. The sensitivity for antibiotics was tested by the standard dilution micromethod. In blood most frequently Staphylococcus epidermidis was isolated (45.4%), coagulase-negative strains of Staphylococcus haemolyticus, Staphylococcus hominis and Staphylococcus saprophyticus (14.4%), Acinetobacter calcoaceticus-baumannii (complex 6.3%) and Pseudomonas aeruginosa (6.3%). In urine the following were detected: Staphylococcus epidermidis (36.5%), Enterococcus sp. (14.5%), Escherichia coli (13.1%), Enterococcus faecalis (11.6%) and Enterococcus solitarius (6.5%). In all strains resistance to antibiotics and chemotherapeutic drugs was assessed. CONCLUSIONS: Investigation of the frequency of different bacterial species, along with monitoring of the resistance is an essential prerequisite of initial antibiotic therapy of febrile episodes in neutropenic patients.

[Comparison of the results of antibiotics sensitivity tests using the standard microdilution method on isolated bacteria and the direct disc method on positive hemocultures from the automatic BacT/Alert system]. / Porovnání výsledku testování citlivosti k antibiotikum standardní dilucní mikrometodou u izolovaných bakterií a "prímou" diskovou metodou u pozitivných hemokultur z automatického systému BacT/Alert.

During a six-month period 2,221 haemocultures obtained from patients hospitalized in the Faculty Hospital Olomouc were examined. In all 304 isolated bacteria the sensitivity was assessed by the standard dilution micromethod and moreover all positive haemocultures were examined the "direct" disc method. Agreement between the results of the two methods was proved in 84% of pairs of tests and within a range from 67 to 100%, depending on the type of antimicrobial preparation. Based on these findings it may be stated that assessment of the sensitivity by the "direct" method agrees significantly with assessment of the sensitivity according to minimal inhibitory concentrations (MIC). In patients with septicaemia this procedure makes it possible to change empirical antibiotherapy by 24 hours sooner to aimed therapy.