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K J Forbes

Publications and source records attributed to K J Forbes.

25 records · Page 2Linked to original sources
PubMed1993

An analysis of the diversity of Haemophilus parainfluenzae in the adult human respiratory tract by genomic DNA fingerprinting.

A method for typing Haemophilus species is described, based on the analysis of genomic DNA from Haemophilus parainfluenzae. The DNA was extracted by a rapid method and digested with the restriction enzyme BamHI to provide a characteristic 'fingerprint'. The pattern of fragments in the ranges 1-1.6 kb, 1.6-2 kb and 2-3 kb were used to produce a numerical profile of each isolate. In total 97 isolates were examined; 88 from throat swab material isolated from the 15 members of a British Antarctic Survey base and 9 type strains. Seventy-two of the 88 antarctic isolates were H. parainfluenzae and were found to be very diverse, comprising 41 identifiable strains with up to 5 strains being isolated from a single throat swab sample. There was evidence for both carriage and transmission within the isolated community. The technique provided a highly discriminatory method for characterizing Haemophilus strains which is suitable for epidemiological studies.

Adult↗
PubMed1992

Variation in length and sequence of porin (ompP2) alleles of non-capsulate Haemophilus influenzae.

Length variations of Haemophilus influenzae outer membrane porin protein P2 were found at the DNA and protein levels, notably in non-capsulate strains. Protein length, measured by SDS-polyacrylamide gel electrophoresis, was found to correlate with the length of the gene, measured by polymerase chain reaction amplification, and ranged from 35-42 kDa and 970-1090 nucleotides, respectively. This represents a length variation of some 15%. The genetic location of these variations was studied by restriction enzyme mapping 10 of the non-capsulate strains revealing further polymorphisms at the DNA level. All 10 strains were distinct and differed from a type b strain. The conservation and assortment of the different restriction sites in the alleles is discussed in relation to the very great diversity previously described for this protein and of the whole genome itself in non-capsulate strains. The roles of selection, horizontal gene transfer, and transformation in generating this diversity are discussed.

Alleles↗
PubMed1990

Salmonella septic arthritis: a case report and review.

We describe a case of septic arthritis in a child with no apparent predisposing conditions. Salmonella virchow was isolated from her knee and faeces, both isolates being identical except for the latter's resistance to ampicillin. Evidence is presented for the acquisition of ampicillin resistance in vivo, including the demonstration of the R plasmid and its ready transferability to Escherichia coli. The recent literature on the subject is reviewed and the role of group CI salmonellae in invasive disease is examined.

Ampicillin Resistance↗
PubMed1985

Chromosomal mapping in Erwinia carotovora subsp. carotovora with the IncP plasmid R68::Mu.

Conjugational gene transfer was established in Erwinia carotovora subsp. carotovora SCRI193 by using plasmid R68::Mu c+ to mobilize the chromosome into multiply mutant recipients. It was observed that although the plasmid alone mobilized markers randomly at a frequency of ca. 10(-5) chromosomal recombinants per donor, the presence of a Mu prophage on the chromosome of the donor increased the frequency of mobilization of markers adjacent to the prophage by up to 10-fold. Using this system it was possible to order 17 chromosomal mutations. The behavior of Mu in E. carotovora subsp. carotovora was also studied.

Bacteriophage mu↗