Treatment Failure in a UK Malaria Patient Harboring Genetically Variant Plasmodium falciparum From Uganda With Reduced In Vitro Susceptibility to Artemisinin and Lumefantrine.

Background: Recent cases of clinical failure in malaria patients in the United Kingdom (UK) treated with artemether-lumefantrine have implications for malaria chemotherapy worldwide.

Methods: Parasites were isolated from an index case of confirmed Plasmodium falciparum treatment failure after standard treatment, and from comparable travel-acquired UK malaria cases. Drug susceptibility in vitro and genotypes at 6 resistance-associated loci were determined for all parasite isolates and compared with clinical outcomes for each parasite donor.

Codon-optimized DsRed fluorescent protein for use in Mycobacterium tuberculosis.

Objective: We have previously codon-optimized a number of red fluorescent proteins for use in Mycobacterium tuberculosis (mCherry, tdTomato, Turbo-635). We aimed to expand this repertoire to include DsRed, another widely used and flexible red fluorescent protein.

Results: We generated expression constructs with a full length DsRed under the control of one of three strong, constitutive promoters (P, P or P) for use in mycobacteria.

Mycobacterium tuberculosis H37Rv has a single nucleotide polymorphism in PhoR which affects cell wall hydrophobicity and gene expression.

Mycobacterium tuberculosis is a successful pathogen that can adapt to multiple environmental niches. As part of its repertoire of adaptive responses, two-component regulatory systems play a major role in co-ordinating gene expression at the global level. The PhoPR system controls major cellular functions, including respiration, lipid metabolism, the immediate and enduring hypoxic responses, stress responses and persistence.

Identification of the translational start site of codon-optimized mCherry in Mycobacterium tuberculosis.

Background: Fluorescent proteins are used widely as reporter genes in many organisms. We previously codon-optimized mCherry for Mycobacterium tuberculosis and generated expression constructs with high level expression in mycobacteria with multiple uses in vitro and in vivo. However, little is known about the expression of fluorescent proteins in mycobacteria and the translational start codon for mCherry has not been experimentally determined.

Sensitive detection of gene expression in mycobacteria under replicating and non-replicating conditions using optimized far-red reporters.

Fluorescent reporter proteins have proven useful for imaging techniques in many organisms. We constructed optimized expression systems for several fluorescent proteins from the far-red region of the spectrum and analyzed their utility in several mycobacterial species. Plasmids expressing variants of the Discosoma Red fluorescent protein (DsRed) from the Mycobacterium bovis hsp60 promoter were unstable; in contrast expression from the Mycobacterium smegmatis rpsA promoter was stable.