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Biomedical subjects

D Kusch

Publications and source records attributed to D Kusch.

13 recordsLinked to original sources
PubMed1997

In vitro photo-activation of newly synthesized chlorin derivatives with red-light-emitting diodes.

We investigated the in vitro photo-activation properties of two chlorin derivatives, i.e. 8-cis-heptylchlorin dicarboxylic acid and 3-trans-heptylchlorin bisamidoglucose derivative, which exhibit lipophilic properties similar to those of the active fractions of Photofrin II, on a normal epithelial cell line (FRTL-5). We used as an irradiation source an array of diodes emitting red light (lambda = 675 nm), which produced a fluence of 7mW cm-2 on the cells. We found that photo-activation with chlorin derivatives in the concentration range 1-100 ng ml-1 greatly enhanced the mortality of the irradiated cells (energy density, 0.25 J cm-2) with respect to the control cells kept in the dark. This response is immediate and appears to be an "all or none' effect. Taking into account that compounds exhibit a strong absorbance peak in the long wavelength region of visible light where tissues are relatively transparent, our results suggest that chlorins can be considered to be good candidates for application in photodynamic therapy.

Animals↗
PubMed1980

[Phage-typing of Staphylococcus aureus from slaughtered poultry (author's transl)].

445 strains of Staphylococcus aureus were isolated from poultry and further 345 strains were isolated from the personnel of a poultry processing plant. The strains were typed with the International Basic Set and a set of poultry phages according to Gibbs et al. (1978b). In total, it was possible to type 38% more of the staphlococci with the poultry set than with the human set, of which the most frequent phage reaction occurred in phage groups III (human set) and B1 (poultry set). 83% of all the strains which were not typable, using the International Basic Set, were however typable with the poultry set. - Poultry specific staphylococci, classified according to biochemical characteristics, in general did not react with the human set. They did, however, show the most frequent reaction in phage groups A and A/B2 of the poultry set. - The human specific strains were almost all typable with the International Basic Set. They also reacted frequently with the phage group B1 of the poultry set, mainly in combinations of B1/III and B1/NT. - In contrast to the International Basic Set, the poultry phage set exhibited a lower specifiy, in that a greater number of strains were typable with the poultry set which were classified by biochemical characteristics as human specific. - It was also possible to type about 70% of the human staphylococci with both sets. A clear classification into the poultry biotype appeared to be possible only with strains reacting with phages of group A of the poultry set.

Animals↗
PubMed1979

[Staphylococcus aureus in poultry--biochemical characteristics, antibiotic resistance and phage pattern (author's transl)].

In a poultry processing plant in northern Germany 1412 swabs were taken from poultry carcasses together with 608 swabs from the personnel. The broilers came from 22 different chicken farms. The swabs taken from the poultry and those taken from the personnel proved to be 35% and 48% Staph. aureus positive respectively. The swabs taken from the feathers and from the skin were staphylococcal positive at a higher level (47%) than the swabs taken from the cloaca (19%) and the throat (23%). Between 8% and 63% of the animals from the various chicken farms were Staph. aureus positive. The frequency of staphylococcal contamination increased during the course of slaughter. 57% of the swabs taken from the gloves and the hands and 42% from the aprons of the personnel were Staph. aureus positive. Some biochemical properties, the phage patterns, and the antibiotic resistance against oleandomycin, erythromycin, bacitracin, streptomycin, tetracyclin, penicillin, chloramphenicol, virginiamycin and flavomycin were determined from 445 poultry and 345 personnel Staph. aureus isolates. Only small differences could be established between both sources in this way. Only 20% of the personnel and 34% of the chicken strains were resistant to antibiotics. In the strains collected from personnel, penicillin-resistance predominated while the poultry isolates showed predominantly tetracyclin-resistance. Of all antibiotics applied nutritively in the chicken fattening, there was a higher resistance only against oleandomycin (11% of the poultry strains). Between the chicken farms there was a different frequency of resistance (0--68%). The source of the staphylococci could be determined for only some of the strains. Only 2.5% of the chicken isolates showed characteristics described in the literature to be "poultry-specific", whereas 37% of the personnel and 24% of the poultry isolates were shown to be "human-specific" strains. It seems that the vast majority of the staphylococci originated from the slaughterhouse personnel. The rest of the strains differed in varying combinations of their properties from the given species characteristics. Although Staph. aureus was brought into the slaughterhouse by the poultry, the contaminations of the final product seemed to originate mainly from human beings.

Abattoirs↗
PubMed1978

ICMSF methods studies. X. An international comparative study of four media for the enumeration of Staphylococcus aureus in foods.

An international comparative study, undertaken by six laboratories to assess the performance of four selective media commonly used for the enumeration of Staphylococcus aureus in foods, revealed that Baird-Parker agar performed most satisfactorily. There was no significant difference among milk salt, tellurite polymyxin egg yolk, and kalium rhodanid - actidione - natriumazid - eigelb - pyruvat (KRANEP) agars. The type of food examined appeared to influence the performance of the media, but no specific patterns could be determined. Cultures yielding 3+ and 4+ coagulase reactions are most likely to possess thermostable nuclease activity, and are therefore most likely to be S. aureus.

Culture Media↗