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Biomedical subjects

I Klare

Publications and source records attributed to I Klare.

At least 19 recordsLinked to original sources

Nosocomial cross transmission as a primary cause of vancomycin-resistant enterococci in Austria.

Stool specimens from 226 patients from intensive care units (N=69), general wards (N=112), and outpatient-clinics (N=45) at the Innsbruck University Hospital and from 433 healthy volunteers were inoculated on to Enterococcosel Agar supplemented with 5 microg/mL vancomycin and 4 microg/mL cefodizime. Faecal specimens from 105 dairy cows, 171 pigs and 47 egg-laying hens were processed the same way. Thirteen of 226 patients (5.8%) harboured 14 vancomycin-resistant enterococci (VRE) of the vanA genotype; 12 E. faecium (from 11 patients) and two E. faecalis (ICU patients: 5.8%, general ward patients: 5.4%, outpatients: 6.7%). None of the faecal specimens from healthy volunteers or animals yielded VRE. Nine of the 13 patients harbouring VRE had received antibiotic therapy during the previous four weeks (broad-spectrum cephalosporins: six patients; i.v. vancomycin: five patients). Of the 14 VRE (vanA type) isolates six strains were indistinguishable by PFGE using Sma I as restriction endonuclease, six strains formed three pairs, and only two single isolates showed unique patterns. The results of our study supports the view that nosocomial cross transmission is currently the main cause of colonization and infection with VRE in Austria.

Animals↗

Quinupristin/dalfopristin-resistant enterococci of the satA (vatD) and satG (vatE) genotypes from different ecological origins in Germany.

The semisynthetic streptogramin combination quinupristin/dalfopristin (Synercid) is a promising alternative for treatment of infections due to multiply resistant gram-positive bacteria including vancomycin-resistant Enterococcus faecium. Resistance is mediated by acetyltransferases SatA (VatD) or SatG (VatE). Recent papers have indicated a possible link between the use of the streptogramin virginiamycin S/M as a feed additive in commercial animal husbandry and a selection of quinupristin/dalfopristin-resistant E. faecium (QDRE). We screened manure samples from two different turkey farms and from six different pig farms (using virginiamycin), samples from a sewage water treatment plant, 24 broiler carcasses, 10 pork samples, and 200 stool samples of nonhospitalized humans for QDRE. Our strain culture collection of hospital E. faecium isolates from the last 2 years was also reviewed for QDRE. All manure and sewage samples were positive for QDRE, as well as 11 from broiler carcasses (46%), 1 from pork (10%), and 28 from human stool specimens (14%). Thirty-six hospital isolates of E. faecium exhibited resistance to quinupristin/dalfopristin. In 141 QDRE of different origin satA (vatD) and satG (vatE) genes were detected (seven isolates from humans with an unknown resistance mechanism). Streptogramin resistance determinants were tansferable in filtermating experiments for 5 of 10 satA (vatD) and 9 of 22 satG (vatE) isolates. Different EcoRI patterns of satG (vatE) plasmids and corresponding hybridizations of the satG (vatE) gene indicated nonhomologous resistance plasmids in isolates of different origin. The results of this study indicate a common gene pool for streptogramin resistance in E. faecium of different ecological origin. A selection of QDRE using the streptogramin virginiamycin S/M as a feed additive and a spread of the resistance via the food chain to humans is probable.

Acetyltransferases↗

Selective pressure by antibiotics as feed additives.

Antibacterial substances are used in considerable amounts as growth promoters in animal husbandry. There are, however, incalculable risks for human health resulting from the use of particular feed additives. Even 30 years ago the detection of transferable antibiotic resistance in Enterobacteriaceae led to the demand that antibiotics used in human chemotherapy, or for which cross-resistance against human therapeutics has been demonstrated, should be prohibited as growth promoters. The application of molecular methods to typing and characterization of bacteria and their resistance genes has provided more concise evidence for the transfer of antibiotic resistance among animal husbandry and humans as to resistance to glycopeptides (vanA gene cluster) and to streptogramins (satA).

Animal Feed↗

Decreased incidence of VanA-type vancomycin-resistant enterococci isolated from poultry meat and from fecal samples of humans in the community after discontinuation of avoparcin usage in animal husbandry.

The use of the glycopeptide antibiotic avoparcin (AVO) as a feed additive in animal husbandry of many European countries led in 1994-1995 to frequent isolation of VanA-type vancomycin-resistant enterococci (VRE) from commercially produced animal foodstuffs as well as from fecal samples of nonhospitalized persons in Germany (Saxony-Anhalt state). However, at the end of 1997, a decreasing number of such VRE was detected in frozen and fresh poultry meat (chickens and turkeys) from German producers. At this point in time, AVO had been discontinued in animal husbandry for more than 2 and one-half years in Denmark/Norway, nearly 2 years in Germany, and about 8-9 months in all countries of the European Community and Switzerland, respectively. VRE were then only detected in very low concentrations in one-quarter of the poultry meat samples (eight of 31, originating from 18 distinct German producers and bought in 12 different supermarkets). A decline of VRE prevalence was also observed in the gut flora of healthy persons (VRE carriers) in the same region (Saxony-Anhalt state, Germany), having fallen from 12% (12/100) in 1994 when AVO was being used to 6% (6/100) in 1996 and 3% (13/400) in 1997 after it was discontinued. These results likely indicate the importance of antibiotic selective pressure by glycopeptides such as AVO for the presence of VRE in animal meat products from commercial animal husbandry. Additionally, it underlines the role of animal products for the spread of resistant bacteria and transferable resistance genes to humans in the community.

Animal Husbandry↗

Survey of antibiotic resistance among enterococci in North Rhine-Westphalia, Germany.

A surveillance study on antibiotic resistance of enterococcal isolates (n = 730) was carried out in North Rhine-Westphalia, Germany, in 1997. Resistance rates to ampicillin (7.4%), high-level gentamicin (15.0%), high-level streptomycin (27.9%), ciprofloxacin (37.9%), vancomycin (1.5%), and teicoplanin (1.5%) were determined. All vancomycin-resistant enterococci (VRE) carried the vanA gene. SmaI and ApaI macrorestriction patterns indicated an intra- and interhospital spread of VRE.

Bacterial Proteins↗

Arrangement of the vanA gene cluster in enterococci of different ecological origin.

Glycopeptide-resistant enterococci (vanA) isolated from infections in humans, from non-hospitalized humans, from sewage, from animal feces and from meat products in Germany (20 Enterococcus faecium and one Enterococcus hirae) were investigated for the arrangement of the genes in the vanA gene cluster by means of overlapping PCR with five primer pairs. In 20 of these strains, the vanA gene clusters were uniform which suggests a horizontal spread among different ecosystems. In one clinical isolate a rearrangement was detected in the vanY-vanZ region.

Animals↗

[Vancomycin resistant enterococci in Austria].

This study reports pheno- and genotypical analysis of 9 isolates of vancomycin-resistant enterococci (VRE) and 5 vancomycin-sensitive enterococci (VSE) in Austria: 5 E, faecium isolates of 4 patients (the sole patients demonstrating VRE at the University Hospital of Innsbruck in 1994 and 1995), 3 glycopeptide-sensitive isolates collected in Innsbruck in February 1996 for epidemiological analysis, and 6 enterococcus isolates from the University Hospitals of Vienna and Graz. The pheno- and genotypical analyses of all glycopeptide highly resistant E. faecium and E. faecalis isolates indicated the presence of VanA type resistance. One E. casseliflavus strain with intrinsic VanC-1 resistance showed a characteristic constitutive low-level resistance to vancomycin and susceptibility to teicoplanin. Genotyping with macro-restriction analysis demonstrated that 3 VRE isolates of the 5 E. faecium specimens were identical; the same applied to 2 VSE isolates. The two patients with VRE had been cared for at the same time in a surgical ICU and likewise, the two patients with VSE were simultaneously treated at a neurological ICU. The genotyping of E. faecalis strains showed that two strains of the three VRE isolates exhibited identical patterns. Epidemiological investigation did not reveal a mode of transmission for this cluster. Two of the 8 patients with VRE died within 60 days after isolation of the bacteria; the doctors in charge did not consider that the enterococci had been the cause of death. The results of our study indicate that oral vancomycin administration to humans is a primary cause of VRE in Austrian hospitals. In Austria approximately 66 kg vancomycin, 20% of it given orally, are administered to patients per year. Approx. 18-20 tons Avotan (active ingredient Avoparcin-10%)/year were used in Austria; as of April 1, 1997 the use of this animal foodstuff supplement is prohibited by the European Commission.

Administration, Oral↗

vanA-mediated high-level glycopeptide resistance in Enterococcus faecium from animal husbandry.

Glycopeptide-resistant Enterococcus faecium strains were isolated from a pig farm and a poultry farm both using avoparcin as a food additive. Such organisms were not isolated in a hen's eggs-producing farm not using avoparcin. Glycopeptide-resistant enterococci were also detected in broiler chicken carcasses that were delivered to a hospital's kitchen. The resistance was determined by the vanA gene as indicated by the detection of the inducible 39-kDa cytoplasmic membrane protein and of a vanA-specific DNA sequence amplified by polymerase chain reaction. Genomic DNA fragment patterns of strains from animal sources were different from each other and also from those of strains isolated in hospitals and from sewage treatment plants. This findings suggest the dissemination of the vanA determinant among different enterococcal strains of distinct ecological origin.

Animal Husbandry↗

Enterococcus faecium strains with vanA-mediated high-level glycopeptide resistance isolated from animal foodstuffs and fecal samples of humans in the community.

The occurrence and the further spread of high-level glycopeptide-resistant, vanA-positive Enterococcus faecium strains outside of hospitals have been investigated. We could isolate such bacteria directly from thawing liquids of commercially produced frozen poultry (chickens, turkeys; no further data on previous feeding with avoparcin were available). In 5 of 13 samples of raw minced meat of pigs originating from 13 different butcher's shops, glycopeptide-resistant E. faecium (VanA type) could be detected after overnight broth cultivation of these samples. No glycopeptide-resistant enterococci could be isolated from meat samples of chickens that were fed without avoparcin. VanA type E. faecium strains were also identified in 12 fecal samples recovered from 100 nonhospitalized humans in the rural area of Saxony-Anhalt federal county. These results suggest a possible role of the food chain in the spread of glycopeptide-resistant E. faecium. Molecular typing (macrorestriction and multilocus enzyme analysis) reveal a wide dissemination of the vanA gene among strains of different ecological origins.

Animals↗

Automated laser fluorescence analysis of randomly amplified polymorphic DNA: a rapid method for investigating nosocomial transmission of Acinetobacter baumannii.

A rapid method for genotyping Acinetobacter baumannii based on PCR-fingerprinting with fluorescent primers was evaluated. Automated laser fluorescence analysis (ALFA) enabled on-line generation of high resolution DNA-fingerprints during polyacrylamide gel electrophoresis of randomly amplified polymorphic DNA (RAPD) products. The results were in concordance with macro-restriction fragment patterns produced by pulse-field gel electrophoresis (PFGE) of ApaI digests of chromosomal DNA. RAPD-ALFA was able to identify homologous strains suggestive of horizontal transmission in < 8 h after colonies were obtained on solid media, whereas PFGE analysis took c. 90 h. Speed and digitised data format renders RAPD-ALFA attractive for routine in-house epidemiological screening of isolates from intensive care and other hospital units.

Acinetobacter↗

Clinical significance and spread of fluoroquinolone resistant uropathogens in hospitalised urological patients.

The minimum inhibitory concentrations (MIC) of ciprofloxacin were determined for 441 uropathogens from patients with complicated and/or hospital acquired urinary tract infections (UTI). None of the Enterobacteriaceae was resistant (MIC > or = 4 mg/l), but 21.7% of enterococci, 28.3% of Pseudomonas spp. and 38.5% of staphylococci were. Subtyping of the strains revealed that with staphylococci there was no clonal spread of resistant strains. In the case of enterococci and Pseudomonas spp., however, cross infections played a major role (46% and 40% respectively). In a retrospective analysis of 370 UTI episodes caused by Pseudomonas aeruginosa (74), enterococci (185) or staphylococci (111) there was no difference between sensitive and resistant strains with respect to clinical aspects and rates of elimination by appropriate anti-bacterial therapy. The rates of spontaneous disappearance without antibacterial therapy ranged from 28% in the case of P. aeruginosa up to 63% in the case of coagulase-negative staphylococci. This implies that especially in UTI caused by gram-positive cocci an indication for antibacterial therapy should be weighted thoroughly and fluoroquinolones should only be used in accordance with sensitivity testing.

Anti-Infective Agents↗

Environmental strains of Enterococcus faecium with inducible high-level resistance to glycopeptides.

High-level resistance to glycopeptides in Enterococcus faecium is associated with an inducible 39-kDa cytoplasmic membrane protein. The present paper shows that such glycopeptide-resistant E. faecium strains can not only be isolated in a definite clinical setting but also from waste water of sewage treatment plants. Nearer characterization of these and of clinical isolates by resistance pattern, biotyping, and genotyping (DNA-fingerprinting with pulsed-field gel electrophoresis) has shown that different glycopeptide-resistant E. faecium strains have been isolated from clinical sources and from waste water.

DNA Fingerprinting↗