Occurrence of aminoglycoside-modifying-enzyme genes aac(6')-aph(2"), aph(3'), ant(4') and ant(6) in clinical isolates of Enterococcus faecalis resistant to high-level of gentamicin and amikacin.

The genes coding for 4 aminoglycoside-modifying enzymes AAC(6')-APH(2"), APH(3'), ANT(4') and ANT(6) were determined in 44 Slovak clinical isolates of Enterococcus faecalis with high-level resistance to gentamicin (HLGR, collection 1) and 48 E. faecalis isolates with resistance to amikacin (AR, collection 2). The occurrence of spotted genes was (collection 1 vs. collection 2): aac(6)-aph(2") 81.8 vs. 8.3 %, ant(4') 52.3 vs. 81.3 %, aph(3') 50 vs. 56.3 % and ant(6) 6.8 vs. 4.2 %, the most frequent combinations of genes in the HLGR collection were aac(6')-aph(2") + ant(4') and aac(6')-aph(2") + aph(3). In contrast, the aph(3') + ant(4') gene profile was predominant in AR isolates. None of the isolates contained all four AGME genes simultaneously.

Bacteremia due to Pseudomonas aeruginosa: results from a 3-year national study in the Slovak Republic.

Risk factors, mortality and antimicrobial susceptibility of Pseudomonas aeruginosa bacteremias isolated from 148 patients from all University Hospitals in Slovakia were analyzed. Only 1.2% of 169 strains of P. aeruginosa were resistant to meropenem, 4.1% to piperacillin/tazobactam, 7.7% to ceftazidime as well as cefepime and 12% to amikacin. More than 30% of P. aeruginosa were resistant to ciprofloxacin. Our analysis of risk factors for antimicrobial resistance to the particular antimicrobials, indicated no difference in risk factors and outcome in cases infected with P. aeruginosa bacteremias resistant to amikacin, piperacillin/tazobactam or ceftazidime in comparison to episodes caused by P. aeruginosa due to susceptible isolates. When comparing risk factors for P. aeruginosa bacteremia in children vs. adults, cancer vs. non-cancer patients, several differences in risk factors were observed. Neither antimicrobial resistance to amikacin, ceftazidime or piperacillin/tazobactam, nor appropriateness of therapy according to two separate analyses were associated with better outcome.

[Evidence of enterotoxins and toxic shock syndrome toxin (TSST-1) in strains of Staphylococcus aureus isolated from various biological materials]. / Dôkaz enterotoxínov a toxínu sokového syndrómu (TSST-1) u kmenov Staphylococcus aureus izolovaných od pacientov z rôzneho biologického materiálu.

Among 413 strains of S. aureus isolated from patients with chronic staphylococcal infections, from haemocultures in bacteriaemia and septic conditions, from gynaecological materials and nasal plugs of healthy carriers the authors detected the production of one or several types of enterotoxins in 124 strains (30.0%), production of TSST-1 in 19 strains (4.6%) and the concurrent production of enterotoxins and TSST-1 in 38 strains (9.2%). The highest ratio of toxigenic strains of S. aureus was found in departments (51.4%) and from hospitalized patients in blood cultures in bacteriaemias and septic conditions (41.2%). In a group of 184 strains from patients with chronic staphylococcal infection toxin production was proved in 49 strains (26.6%). Of 74 strains of S. aureus isolated from healthy carriers there were 16 toxigenic strains (21.6%). The most frequent type of enterotoxins were enterotoxins type A (26.7%) and C (24.4%). 21 strains (24.4%) produced more than one type of enterotoxins.

Breakthrough candidaemias during empirical therapy with fluconazole in non-cancer and non-HIV adults caused by in vitro-susceptible Candida spp.: report of 33 cases.

The objective of this study was to assess risk factors and the outcome of breakthrough fungaemias (BFs) occurring during fluconazole (FLU) therapy in non-cancer and non-HIV individuals. Thirty-three fungaemias occurring during therapy with FLU among a total of 310 fungaemias observed within a 10-y national survey were analysed. The agar disk diffusion method was used for antifungal susceptibility testing and the Vitek system for species identification. Univariate and multivariate analysis was performed to determine risk factors for BF. All BFs were due to species known to be susceptible to FLU: Candida albicans (25/33), C. parapsilosis (6/33) and C. guillermondii (2/33). The mean number of positive blood cultures per episode was 2.4. The MIC of Candida spp. to FLU was 0.5-8 mg/ml (all strains were susceptible in vitro). Neonatal age (< 4 weeks), very low birth weight, prior surgery, central venous catheter placement, artificial ventilation, total parenteral nutrition and C. parapsilosis were significantly related to BF in univariate analysis, but only central venous catheter placement was significantly related in multivariate analysis. However, the outcome of BFs and non-BFs was similar. All BFs occurred in non-HIV patients who were not previously treated with azoles, and were caused by in vitro FLU-susceptible species (C. albicans and C. tropicalis). Thus factors other than in vitro susceptibility play a role in BFs.

Persistent fungemia--risk factors and outcome in 40 episodes.

The aim of this multicenter survey was to assess risk factors and mortality in patients with persistent fungemia (PF). Cases of persistent fungemia, defined as positive blood culture for at least 3 causative days of antifungal therapy were selected. Forty cases of persistent fungemia (lasting more than 3 days) were compared with 270 non-persistent fungemias appearing within the same period, and analyzed by univariate and multivariate analysis for risk factors and outcome. The median number of days of positive culture was 4.4 (3 - 20): 22 episodes were due to Candida albicans, 1 due to non-albicans Candida spp., 6 episodes due to non-Candida spp. Yeasts: 15 were catheter related, 16 patients had yeast-infected surgical wounds, 12 were neutropenic, 4 cases were caused by species resistant in vitro, 2 to amphotericin B (Trichosporon spp.) and 2 to fluconazole (C. laurentii, C. glabrata). Fifteen patients (37.5%) died, 7 of whom due to fungemia. Nineteen cases had one known risk factor (10 had infected wound, 4 infected vascular catheter, 3 were neutropenic and 2 had inappropriate therapy). Fourteen cases had two known risk factors (4 had wound and infected catheter, 4 neutropenia and infected catheter, 2 neutropenia and resistant organism, 4 other combinations. Two cases had 3 known risk factors and one had 4 risk factors for persistent fungemia. Artificial ventilation, C. glabrata etiology, non-Candida spp. yeasts such as Trichosporon spp. and Cryptococcus spp. and prior surgery were significantly associated with persistent fungemia in univariate, whereas only C. glabrata etiology in multivariate analysis. Breakthrough fungemia during empiric therapy with fluconazole was also observed more frequently in patients with persistent fungemia. However, there was no difference in both attributable and overall mortality between both groups.

Breakthrough fungaemia in neonates and infants caused by Candida albicans and Candida parapsilosis susceptible to fluconazole in vitro.

Breakthrough fungaemias due to Candida albicans and Candida parapsilosis appearing during fluconazole therapy in neonates and infants were assessed for risk factors and outcome. Forty fungaemias occurred during therapy with fluconazole within a 12 year national survey and were compared with 161 cases of non-breakthrough paediatric fungaemias. The agar disc diffusion test method was used for antifungal susceptibility testing and the Vitek system for species identification. Univariate and multivariate analysis for risk factors for breakthrough fungaemia were carried out. All the fungaemias were a result of strains susceptible to fluconazole at 0.25-4 mg/L in vitro [C. albicans (85%) and C. parapsilosis (15%)]. The mean number of positive blood cultures per episode was 2.2. Sixteen children had 'early' breakthrough fungaemias (within 4-5 days) and 24 fungaemias appeared on day 6 and later. Mean fluconazole MICs in the 'early' group were 1.2, and 2.8 mg/L in the 'late' group (P < 0.03, t-test). However, no difference was observed in the average dose of fluconazole used in the two groups. Neonatal age, total parenteral nutrition, very low birth weight, before surgery, central or umbilical venous catheterization and artificial ventilation were all significantly related to breakthrough fungaemia in univariate analysis but only central or umbilical venous catheterization were significant in multivariate analysis. The outcome of breakthrough fungaemia was better overall and attributable mortalities in non-breakthrough fungaemia was significantly higher in comparison with breakthrough fungaemia.

[Coagulase negative staphylococci isolated on blood cultures]. / Koaguláza negatívne stafylokoky izolované z hemokultúr.

224 coagulase-negative strains of staphylococci (CNS) isolated from haemocultures of hospitalized patients were classified into 11 types. The most frequent one was S. epidermis (73.2%), S. haemolyticus (7.6%), S. lugdunensis (6.7%) and S. hominis (3.6%). In different strains virulence factors were assessed: production of mucus and delta toxin. Based on these properties the strains were classified into biotypes. Of 164 strains of S. epidermis mucus was produced by 64.6% and delta toxin by 75.0%. Of 17 strains of S. haemolyticus mucus was produced by 8 and delta toxin by 10 strains. Of 15 strains of S. lugdunensis 9 strains produced both virulence factors. Of 8 strains of S. hominis 5 strains produced mucus and 3 delta toxin. In strains S. capitis, S. sciuri, S. auricularis, S. caprae these factors were not detected. The most frequent biotypes were: subtype 3 (43.3%), 1a (26.8%) and 1b (10.3%). The sensitivity of CNS to 11 antibacterial substances was assessed quantitatively by estimating the MIC (mg/l). The most effective antibiotic was vancomycin (100%) and tetracycline (76.8%). Only 26.3% strains were sensitive to oxacillin and cefalotine. Of 224 CNS (70%) were resistant to more than 8 antibacterial substances.

Nosocomial fungemia due to amphotericin B-resistant Candida spp. in three pediatric patients after previous neurosurgery for brain tumors.

Amphotericin B (AmB) resistance in Candida spp. is very rare. Three cases of fungemia, due to amphotericin B-resistant Candida spp. in pediatric patients after previous neurosurgery for brain tumors, are reported. The Candida strains - one C. guillermondii, one C. lusitaniae, and one C. parapsilosis - showed minimum inhibitory concentrations (MICs) to AmB of 2-4 microg/ml. Two of the three patients had been pretreated with AmB for 5-11 days. All three patients were successfully treated with intravenous fluconazole (6-10 mg/kg per day) for 16-28 days, and all survived. Despite AmB resistance in Candida spp. being very rare, C. lusitaniae, C. guillermondii, and C. parapsilosis isolates in documented infections should be tested for AmB resistance, mainly in patients not responding to therapy with AmB.

Transferable antibiotic resistance in multiresistant nosocomial Acinetobacter baumannii strains from seven clinics in the Slovak and Czech Republics.

Sixty-seven multiresistant nosocomial Acinetobacter baumannii isolates from patients hospitalized mostly in intensive care units of seven clinics in Slovak and Czech Republic were tested to determine their ability to transfer antibiotic resistance. All isolates were resistant to kanamycin, ticarcillin, cephalothin, cefotaxime, ceftazidime, aztreonam and susceptible to carbapenems, sulbactam and ampicillin/sulbactam. Sixty-five out of 67 strains transferred resistance determinants to Escherichia coli K-12 and Proteus mirabilis P-38 recipients. Analysis of selected transconjugants by an indirect selection method showed a more variable pattern of transferred resistance determinants. The clonal spread of strains transferring resistance seems to be an additional risk for occurrence of strains resistant to ceftazidime and aztreonam.

Occurrence and transferability of beta-lactam resistance in Enterobacteriaceae isolated in Children's University Hospital in Bratislava.

Occurrence and transferability of beta-lactam resistance in 30 multi-resistant Escherichia coli, Klebsiella spp., Enterobacter spp., Pantoea agglomerans, Citrobacter freundii and Serratia marcescens strains isolated from children between 0 and 3 years of age is presented. The strains were resistant to ampicillin (30), cefoxitin (22), cefotaxime (30), ceftriaxone (30), ceftazidime (30) and aztreonam (28), but susceptible to cefepime (30) and imipenem (26). Twenty-eight of 30 isolates possessed a transferable resistance confirmed by conjugation and isolation of 79-89-kb plasmids. The beta-lactam resistance was due to production of beta-lactamases and ceftazidime proved to be stronger beta-lactamase inductor than ceftriaxone. Twenty-five clinical isolates expressed transferable extended spectrum beta-lactamases, and chromosomally encoded AmpC beta-lactamase.

Prospective study of antibacterial susceptibility, risk factors and outcome of 157 episodes of Acinetobacter baumannii bacteremia in 1999 in Slovakia.

This study prospectively investigated all 157 cases of Acinetobacter baumannii bacteremia occurring in major university hospitals or tertiary care institutions in Slovakia during 1999 in order to determine the antimicrobial susceptibility, risk factors and outcome. Resistance to meropenem was 7.4, gentamicin 35.6, amikacin 26.5, cefepime 20.4 and ciprofloxacin 32.7%, but was only 17.3% to cefoperazone/sulbactam or ampicillin/sulbactam. Antimicrobial susceptibility of A. baumanii was lowest among isolates from cancer patients (ceftazidime 58%, piperacillin/tazobactam 52% and azthreonam 48%; p < or = 0.01-0.001). In univariate analysis, several risk factors, such as wound infection (p < or = 0.01) and ventilatory support (p < or = 0.0001), were significantly related to A. baumannii bacteremia in surgical patients. Neutropenia (p < or = 0.0001), antineoplastic chemotherapy (p < or = 0.0001) and prior antibiotic therapy (p < or = 0.0006) were significant risk factors for A. baumannii bacteremia in cancer patients. In addition, ventilatory support and surgery (p < or = 0.0001) and prior antibiotic therapy (p < or = 0.01) were significantly related to A. baumannii bacteremia in children. Colonization at other body sites (p < or = 0.05), diabetes mellitus (p < or = 0.04) and decubital ulcers/burns (p < or = 0.002) as underlying disease were significantly related to death due to A. baumannii bacteremia. In a multiple logistic regression model, decubital ulcers/burns as underlying disease (p < or = 0.0006; relative risk 5.08) and nosocomial pneumonia (p < or = 0.045; relative risk 5.08) were independent predictors of mortality. Mortality was similar between cancer and surgical patients but significantly lower in children vs. adults (p < or = 0.009).

Spectrum and transferability of beta-lactam resistance in hospital strains of Enterobacter isolated in Bratislava and Innsbruck.

The transferability and expression of beta-lactam resistance were compared in multiresistant clinical isolates of Enterobacter spp. collected from different hospitals in Bratislava, Slovakia (n = 15) and Innsbruck, Austria (n = 19) during 1996-1997. The strains from Bratislava were resistant to ampicillin, cefoxitin, cefotaxime, ceftazidime and ceftriaxone. All strains from Innsbruck were resistant to ampicillin and cefoxitin; 17 were also resistant to ceftazidime and aztreonam but the majority remained susceptible to cefotaxime and ceftriaxone. All strains were susceptible to cefepime and imipenem. The majority of the tested strains transferred resistance determinants to E. coli recipient by conjugation. Production of beta-lactamase including ESBL was the major mechanism of beta-lactam resistance. Large plasmids of 77-88 and 91 kb were confirmed in clinical isolates from Bratislava and Innsbruck.

Antifungal susceptibility of 262 bloodstream yeast isolates from a mixed cancer and non-cancer patient population: is there a correlation between in-vitro resistance to fluconazole and the outcome of fungemia?

The aim of this study was to test the antifungal susceptibility of 262 bloodstream yeast isolates (164 Candida albicans strain, 88 non-albicans Candida spp. and 10 non-Candida yeasts) recovered from 169 surgical, neonatal, critically ill intensive care unit patients (ICU), and cancer patients (mixed patient population) to amphotericin B (AmB), fluconazole (FLU), 5-flucytosine (5-FC), itraconazole (ITRA), ketoconazole (KETO), miconazole (MICO), and nystatin (NYS), in order to correlate in-vitro resistance to fluconazole with the outcome of fungemia. The agar disk diffusion test was used to assess the susceptibility of the 262 bloodstream yeasts isolates. In addition, 78 strains isolated from cancer patients were also tested with the E-test. There were no differences in the susceptibility of the various C. albicans strains tested, except in 40 isolates from surgery patients, which showed a somewhat lower susceptibility to KETO and MICO to (3.7-5.5% resistance). There were no C. albicans strains resistant to AmB, NYS, or FLU. There were slight differences in the susceptibility patterns of the 88 non-albicans Candida spp. (NAC) isolates. Resistance to AmB and NYS appeared in 1 strain of C. guillermondii (minimum inhibitory concentration; MIC to AmB; 4 microg/ml) and in 1 strain of C. parapsilosis (MIC to NYS, 8 microg/ml and MIC to AmB, 2 microg/ml). All other NACs were susceptible to both polyenes (AmB and NYS). Nine of the 11 strains of C. krusei were resistant to FLU (MIC >or= 64 microg/ml), the 2 exceptions showed, respectively, MICs for FLU of 6 and 32 microg/ml ("dose-dependent" susceptibility). However, only 2 of 29 C. glabrata strains were fully FLU-resistant (MIC >or= 64 microg/ml), 27 being susceptible with MIC values of 0.5-8 microg/ml. Apart from 9 C. krusei and 2 C. glabrata strains, 2 C. parapsilosis strains and 1 strain of C. tropicalis were also FLU-resistant. Among the 88 NACs, 17.04% were FLU-resistant and 3.7% were KETO- and ITRA-resistant. Resistance to 5-FC and AmB was minimal. We compared the outcomes of patients infected with FLU-resistant vs FLU-susceptible yeasts in 161 evaluable patients treated with FLU. Attributable mortality was significantly higher (19.0% vs 8.6%; P < 0.01) in patients infected with the FLU-resistant yeasts.

Invasive infections due to Clavispora lusitaniae.

Three cases of Clavispora lusitaniae invasive fungal infections are reported. All three infections appeared in cancer patients presented with fungaemia, one additionally with meningitis. Two of them were breakthrough -- they developed during therapy with conventional amphotericin B with a dose of 0.5 mg kg(-1) day(-1) . All three were cured: two with intravenous fluconazol and one with an increasing dose (1 mg kg(-1) day(-1)) of amphotericin B. In one of two breakthrough cases the sensitivity of the strain to antifungals was tested against antifungal agents and showed in vitro resistance to amphotericin B (MIC 2 eta g ml(-1)).

[Transfer of resistance to 3rd generation cephalosporins and aztreonam in strains of Klebsiella pneumoniae producing extended spectrum beta-lactamases]. / Prenosná rezistencia na cefalosporíny 3. generácie a aztreonam u kmenov Klebsiella pneumoniae produkujúcich beta-laktamázy s rozsíreným spektrom úcinku (ESBL).

The authors demonstrated the transferability of antibiotic resistance genes in nosocomial strains of Klebsiella pneumoniae, isolated from newborn children at the Paediatric University Hospital in Bratislava. Strains were resistant to cefotaxime, ceftazidime and aztreonam. The determinants of resistance (carbenicillin, cephaloridine, cefotaxime, ceftazidime and aztreonam) were transferred to recipient strains of Escherichia coli K-12 and Proteus mirabilis P-38. The transfer of resistance determinant from donor strains was demonstrated by the analysis of the resistance spectrum in transconjugant clones of recipient strains by the method of indirect selection. The ability of production of extended spectrum beta-lactamases (ESBL) was demonstrated by the double disc diffusion test. Synergy between clavulanate and cefotaxime, clavulanate and ceftazidime and/or clavulanate and aztreonam indicated production of ESBL by these strains.