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Biomedical subjects

W Witte

Publications and source records attributed to W Witte.

At least 55 records · Page 3Linked to original sources
PubMed1999

Antibiotic resistance in gram-positive bacteria: epidemiological aspects.

The emergence and spread of antibiotic resistance in gram-positive bacterial pathogens has become an increasing problem. There has been a dramatic increase in the prevalence of methicillin-resistant Staphylococcus aureus (MRSA), coagulase-negative staphylococci and enterococci. This is mainly due to the clonal dissemination of certain epidemic multiply-resistant strains, for example, those of MRSA and S. pneumoniae, as well as to the spread of resistance genes as exemplified by those causing glycopeptide resistance in enterococci.

Bacterial Proteins↗
PubMed1999

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↗
PubMed1998

Influenza A outbreak among adolescents in a ski hostel.

An outbreak of influenza A H3N2 with a high attack rate (49%) and abrupt onset (69% became ill within 2 days) occurred among 81 ski school participants who stayed in a crowded hostel in Austria in early 1997. Two students were hospitalized with pneumonia; one of them died. Cultures of blood and/or respiratory secretions from the hospitalized students yielded toxin-producing Staphylococcus aureus. Influenza A H3N2 was confirmed serologically in four participants, including one surviving hospitalized student, and by polymerase chain reaction of lung tissue from the deceased student. This investigation demonstrates that influenza can cause an explosive outbreak among skiers in a crowded hostel, leading to severe complications among previously healthy adolescents.

Adolescent↗
PubMed1998

A database system for fragment patterns of genomic DNA of Staphylococcus aureus.

The increasing use of molecular fingerprints in the epidemiology of bacterial nosocomial infections urgently demands a computerised analysis and storage of corresponding patterns, especially with regard to results obtained at different times and in different laboratories. This paper presents a database system in connection with cluster analysis of clonal relations by using genomic DNA fragment patterns of S. aureus (SmaI-digestion, pulsed-field gel electrophoresis) as an example: The database is operated under MS-Access, version 2.0. The cluster analysis is based on an optimising similarity algorithm.

DNA, Bacterial↗
PubMed1998

Staphylococcal scalded-skin syndrome complicating wound infection in a preterm infant with postoperative chylothorax.

The course of infection in a 3-week-old premature newborn suffering from extensive dermatitis with flaccid blisters is described. Staphylococcus aureus was recovered from a local wound infection around a chest tube inserted to drain a postoperative chylothorax. The strain isolated tested positive for the eta gene for exfoliative toxin A, the causative agent of staphylococcal scalded-skin syndrome (SSSS). In this case, prematurity and loss of chylus with consecutive lymphopenia may have contributed to development of SSSS.

Chylothorax↗
PubMed1998

Assessment of resolution and intercenter reproducibility of results of genotyping Staphylococcus aureus by pulsed-field gel electrophoresis of SmaI macrorestriction fragments: a multicenter study.

Twenty well-characterized isolates of methicillin-resistant Staphylococcus aureus were used to study the optimal resolution and interlaboratory reproducibility of pulsed-field gel electrophoresis (PFGE) of DNA macrorestriction fragments. Five identical isolates (one PFGE type), 5 isolates that produced related PFGE subtypes, and 10 isolates with unique PFGE patterns were analyzed blindly in 12 different laboratories by in-house protocols. In several laboratories a standardized PFGE protocol with a commercial kit was applied successfully as well. Eight of the centers correctly identified the genetic homogeneity of the identical isolates by both the in-house and standard protocols. Four of 12 laboratories failed to produce interpretable data by the standardized protocol, due to technical problems (primarily plug preparation). With the five related isolates, five of eight participants identified the same subtype interrelationships with both in-house and standard protocols. However, two participants identified multiple strain types in this group or classified some of the isolates as unrelated isolates rather than as subtypes. The remaining laboratory failed to distinguish differences between some of the related isolates by utilizing both the in-house and standardized protocols. There were large differences in the relative genome lengths of the isolates as calculated on the basis of the gel pictures. By visual inspection, the numbers of restriction fragments and overall banding pattern similarity in the three groups of isolates showed interlaboratory concordance, but centralized computer analysis of data from four laboratories yielded percent similarity values of only 85% for the group of identical isolates. The differences between the data sets obtained with in-house and standardized protocols could be the experimental parameters which differed with respect to the brand of equipment used, imaging software, running time (20 to 48 h), and pulsing conditions. In conclusion, it appears that the standardization of PFGE depends on controlling a variety of experimental intricacies, as is the case with other bacterial typing procedures.

Bacterial Typing Techniques↗
PubMed1997

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↗
PubMed1997

[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↗
PubMed1997

Impact of antibiotic use in animal feeding on resistance of bacterial pathogens in humans.

With the exception of flavomycin and olaquindox, the antibiotics currently used in European countries as feed additives exert a Gram-positive spectrum of activity. Of these, tylosin and virginiamycin are known for cross-resistance to macrolides, lincosamidines and streptogramines, and avoparcin is known for cross-resistance to vancomycin and teicoplanin. The use of avoparcin in animal husbandry creates a potential reservoir of transferable, vanA-mediated glycopeptide resistance in enterococci. A study in a rural area in Germany where vancomycin-resistant enterococci (VRE) were not isolated from infected humans but found in animal husbandry has shown that VRE are disseminated via meat products and are also found in faecal samples of non-hospitalized humans. VRE of different ecological origin from Germany (hospitals, sewage, food, animal husbandry) are polyclonal as evidenced by macrorestriction patterns and multilocus enzyme electrophoresis, suggesting a wide dissemination of the vanA gene cluster. These results confirm earlier observations on the spread of the sat genes, which confer resistance to a streptothricin antibiotic which has only been used in animal feeding. The resistance determinants were later also found in Escherichia coli from human infections and had spread in the absence of selective pressure.

Animal Nutritional Physiological Phenomena↗