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M I Sinclair

Publications and source records attributed to M I Sinclair.

25 records · Page 2Linked to original sources

Chromosomal insertion of TOL transposons in Pseudomonas aeruginosa PAO.

Insertions of the TOL plasmid transposons Tn4651 and Tn4653 into the Pseudomonas aeruginosa PAO chromosome were isolated by a temperature selection technique. The locations and orientations of 16 insertions were determined by pulsed field gel electrophoresis and Southern hybridization with genomic and TOL DNA probes. All insertions occurred within a 334 kb region of the chromosome (representing less than 6% of the genome) with nine of the inserts clustered within a 10 kb area. Each transposon was able to insert in either orientation. An internal duplication of the 39 kb excisable region of pWW0 was seen in two independent insertions.

Chromosome Mapping↗

Chromosomal location of TOL plasmid DNA in Pseudomonas putida.

The soil isolate Pseudomonas putida MW1000 can grow on toluene and other hydrocarbons; in this respect it is similar to strains of Pseudomonas which carry the TOL plasmid. By conjugation experiments, the genes conferring these growth abilities have been shown to be located on the bacterial chromosome, linked to vil and catB. A 56-kilobase segment of the bacterial chromosome of MW strains carrying the TOL genes can transpose to the IncP-1 plasmid R18-18. Physical analysis of these TOL R18-18 hybrids has shown that the TOL segment is almost identical to the same region found in the TOL plasmid pWW0.

Chromosome Mapping↗

A chromosomally located transposon in Pseudomonas aeruginosa.

A new transposon, Tn2521, coding for carbenicillin, streptomycin, spectinomycin, and sulfanilamide resistance, has been identified in Pseudomonas aeruginosa. The transposon occurs naturally in the chromosome of clinical strains of P. aeruginosa isolated in geographically separated hospitals. This has been demonstrated by its transductional linkage to the pur-136 marker and also by Southern hybridization. Tn2521 is 6.8 kilobases, can transpose from the chromosome to both IncP-1 and IncP-2 plasmid genomes, and has a pattern of restriction endonuclease sites unlike that of any previously described transposon. The carbenicillin resistance carried by Tn2521 is due to the PSE-4 type of beta-lactamase.

Anti-Bacterial Agents↗

Plasmid-determined tobramycin and gentamicin resistance in strains of Pseudomonas aeruginosa from two Sydney hospitals.

Strains of Pseudomonas aeruginosa resistant to gentamicin, tobramycin, streptomycin, and sulphonamide have been isolated from patients at two Sydney hospitals. The multiple resistance of all these strains was due to a transmissible plasmid. The significance of the identification of this plasmid, in this variety of strains and at two hospitals, for the treatment of Ps. aeruginosa infections is discussed.

Anti-Bacterial Agents↗

Transformation of Pseudomonas aeruginosa strain PAO with bacteriophage and plasmid DNA.

A procedure has been developed which allows transformation of P. aeruginosa strain PAO with plasmid and bacteriophage DNA at a frequency of 10(-6) per recipient cell. The method is similar in outline to that developed for Escherichia coli. It involves growing the recipient cells to 3-5 x 10(8) per ml in nutrient broth, washing the cells with 0.1 M MgCl2, resuspending in 0.175 M CaCl2 for 20 min, exposing to DNA for 1 h and then heat pulsing at 42 degrees C for 1 min. Some plasmid markers are expressed immediately, whereas others require time for phenotypic expression.

Bacteriophages↗

Fecal colonization with vancomycin-resistant enterococci in Australia.

To assess the rate of fecal vancomycin-resistant enterococci (VRE) colon ization in Austalia, we examined specimens from 1,085 healthy volunteers. VRE was cultured from 2(0.2%) of 1,085 specimens; both were vanB Enter ococcus faecium, identical by pulsed-field gel electrophoresis, but with a pattern rare in Melbourne hospitals.

Adult↗