Biomedical subjects

C Werckenthin

Publications and source records attributed to C Werckenthin.

3 recordsLinked to original sources

PubMed1996

A novel plasmid from Staphylococcus epidermidis specifying resistance to kanamycin, neomycin and tetracycline.

The naturally occurring plasmid pSTS7 from Staphylococcus epidermidis mediated resistance to tetracycline via a tetL gene and to kanamycin and neomycin via an aadD gene. Plasmid pSTS7 showed partial restriction map and sequence homology to the previously described tetracycline resistance plasmid pNS1981 from Bacillus subtilis and to the kanamycin/neomycin/bleomycin resistance plasmid pUB110 from S. aureus. Sequence analysis of the regions flanking the two resistance genes in pSTS7 led to the identification of a novel site for interplasmid recombination which could explain the derivation of pSTS7 from the incompatible pNS1981- and pUB110-like parental plasmids under tetracycline-selective pressure.

Amino Acid Sequence↗

PubMed1995

Chloramphenicol resistance in Staphylococcus intermedius from a single veterinary centre: evidence for plasmid and chromosomal location of the resistance genes.

A total of seven Staphylococcus intermedius cultures isolated from cases of canine pyoderma were investigated for the genetic basis of chloramphenicol resistance (Cmr). All of these S. intermedius isolates mediated Cmr via the expression of the Cm-inactivating enzyme chloramphenicol acetyltransferase (CAT); the respective cat genes were found to be located on small multicopy plasmids of 3.1 to 4.1 kb in four of the seven cultures. The four Cmr plasmids, designated pSCS20-23, differed upon restriction endonuclease mapping. Hybridization experiments identified all of them to belong to the pC221-family of staphylococcal Cmr plasmids. The expression of all four plasmid-encoded cat genes was inducible with chloramphenicol. The remaining three S. intermedius isolates also harboured an inducible cat gene of the pC221-type which, however, was found to be located in the chromosomal DNA. These differences in the subcellular localisation and consequently in the number of cat gene copies per S. intermedius cell had no influence on the MIC values of Cm exhibited by the respective S. intermedius isolates.

Animals↗

PubMed1995

Insertion elements in Staphylococcus intermedius.

Staphylococcus intermedius cultures from dogs, pigeons, horses and mink were investigated for the prevalence of the insertion elements IS256 and IS257 in relation to their antibiotic resistance. Copies of IS256 could not be detected in any of the Staph. intermedius isolates tested whereas single copies of IS257 occurred in the isolates from dogs and horses. The mink strains did not harbour IS257 elements, whereas Staph. intermedius isolates from pigeons carried multiple copies of IS257 as predicted from the hybridization patterns obtained with a gene probe derived from the internal part of the IS257-encoded transposase gene. Independently of the origin of the Staph. intermedius isolates, all IS257 copies were found to be located in the chromosomal DNA. The large number of chromosomal IS257 copies in the pigeon strains might help to explain chromosomal multiresistance in many of those strains.

Animals↗