Search tips
Search criteria

Results 1-4 (4)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
1.  The genome of the simian and human malaria parasite Plasmodium knowlesi 
Nature  2008;455(7214):799-803.
Plasmodium knowlesi is an intracellular malaria parasite whose natural vertebrate host is Macaca fascicularis (the ‘kra’ monkey); however, it is now increasingly recognized as a significant cause of human malaria, particularly in southeast Asia1,2. Plasmodium knowlesi was the first malaria parasite species in which antigenic variation was demonstrated3, and it has a close phylogenetic relationship to Plasmodium vivax​4, the second most important species of human malaria parasite (reviewed in ref. 4). Despite their relatedness, there are important phenotypic differences between them, such as host blood cell preference, absence of a dormant liver stage or ‘hypnozoite’ in P. knowlesi, and length of the asexual cycle (reviewed in ref. 4). Here we present an analysis of the P. knowlesi (H strain, Pk1(A+) clone5) nuclear genome sequence. This is the first monkey malaria parasite genome to be described, and it provides an opportunity for comparison with the recently completed P. vivax genome4 and other sequenced Plasmodium genomes6-8. In contrast to other Plasmodium genomes, putative variant antigen families are dispersed throughout the genome and are associated with intrachromosomal telomere repeats. One of these families, the KIRs9, contains sequences that collectively match over one-half of the host CD99 extracellular domain, which may represent an unusual form of molecular mimicry.
PMCID: PMC2656934  PMID: 18843368
3.  Amplification of D-xylose and D-glucose isomerase activities in Escherichia coli by gene cloning. 
A recombinant plasmid, designated pUC1002, was constructed by ligation of a HindIII restriction endonuclease fragment of Escherichia coli chromosomal DNA to vector plasmid pMB9. Strains carrying this plasmid were selected by transformation of an E. coli strain bearing the xyl-7 mutation to a xylose-positive (Xyl+) phenotype. Strains containing pUC1002 produced coordinately elevated levels of D-xylose isomerase and D-xylulose kinase. Under appropriate conditions, the isomerase also efficiently catalyzed the conversion of D-glucose to D-fructose.
PMCID: PMC242470  PMID: 6344793
4.  A rapid method for determining decarboxylase and dihydrolase activity 
Journal of Clinical Pathology  1974;27(2):148-152.
A total of 764 fresh clinical isolates were used to test a rapid method for determining lysine, arginine, and ornithine decarboxylase activity as well as arginine dihydrolase activity. The conventional Møller decarboxylase broth was tested in parallel with the rapid method on 234 Enterobacteriaceae and 140 non-fermentative Gram-negative rods. The 0·3% agar method was tested in parallel on 245 Enterobacteriaceae and 146 non-fermentors. All media were checked at half-hour or hourly intervals for up to eight hours, with the final reading taken after incubation for 24 hours at 37°C. The rapid method detected 17 positive decarboxylase or dihydrolase reactions that were not detected by the Møller broth and 16 more than the agar medium when testing Enterobacteriaceae. The corresponding figures for the nonfermentative Gram-negative rods were three and two respectively. Lysine and ornithine decarboxylase were generally detected by the rapid broth in two to four hours' incubation while the arginine decarboxylase and dihydrolase were slower and required six to eight hours. This compares with overnight incubation as the general rule for the Møller broth and agar decarboxylases. The comparable accuracy of the rapid method with conventional techniques and the shorter incubation time required for detection of positive reactions make this procedure well suited to a routine clinical laboratory.
PMCID: PMC478029  PMID: 4824992

Results 1-4 (4)