One Health: The global challenge of epidemic and endemic leishmaniasis

'One Health' proposes the unification of medical and veterinary sciences with the establishment of collaborative ventures in clinical care, surveillance and control of cross-species disease, education, and research into disease pathogenesis, diagnosis, therapy and vaccination. The concept encompasses the human population, domestic animals and wildlife, and the impact that environmental changes ('environmental health') such as global warming will have on these populations. Visceral leishmaniasis is a perfect example of a small companion animal disease for which prevention and control might abolish or decrease the suffering of canine and human patients, and which aligns well with the One Health approach. In this review we discuss how surveillance for leishmaniases is undertaken globally through the control of anthroponootic visceral leishmaniasis (AVL) and zoonotic visceral leishmaniasis (ZVL). The ZVL epidemic has been managed to date by the culling of infected dogs, treatment of human cases and control of the sandfly vector by insecticidal treatment of human homes and the canine reservoir. Recently, preventive vaccination of dogs in Brazil has led to reduction in the incidence of the canine and human disease. Vaccination permits greater dog owner compliance with control measures than a culling programme. Another advance in disease control in Africa is provided by a surveillance programme that combines remote satellite sensing, ecological modelling, vector surveillance and geo-spatial mapping of the distribution of vectors and of the animal-to-animal or animal-to-human pathogen transmission. This coordinated programme generates advisory notices and alerts on emerging infectious disease outbreaks that may impede or avoid the spreading of visceral leishmaniasis to new areas of the planet as a consequence of global warming

Cc RNase: the Ceratitis capitata ortholog of a novel highly conserved protein family in metazoans

Complementary DNA encoding a protein, designated Cc RNase, was isolated from the insect Ceratitis capitata. Deduced amino acid sequence analysis demonstrates that the Cc RNase has strong sequence homology with other uncharacterized proteins predicted from EST sequences belonging to different animal species, therefore defining a new protein family, which is conserved from Caenorhabditis elegans to humans. Phylogenetic analysis data in addition to extensive homolog searches in all available complete genomes suggested that all family members are true orthologs. Proteins belonging to this family are composed of 95 - 101 amino acids. The C. capitata orthologous protein was expressed in Escherichia coli. Despite the fact that the amino acid sequence of Cc RNase does not share any significant similarities with other known ribonucleases, our data give strong evidence in support of the assignment of enzymatic activity to the recombinant protein. The expressed molecule exhibits ribonucleolytic activity against poly( C) and poly( U) synthetic substrates, as well as rRNA. It is also demonstrated that expression of Cc RNase in E. coli inhibits growth of the host cells

cDNA cloning of L-dopa decarboxylase from the eclosion stage of the insect Ceratitis capitata. Evolutionary relationship to other species decarboxylases

The cDNA encoding the L-dopa decarboxylase (ddc) from the eclosion stage of the insect Ceratitis capitata was isolated by PCR and a molecular cloning strategy. The isolated cDNA clone encoded a protein of 431 amino acids with a calculated molecular weight of 47 843 Da. Northern blot analysis of poly(A)(+) RNA showed an aproximately 2 kb transcript. The deduced protein sequence shares a high percentage of homology with Ddc protein sequences of other species. Furthermore, the molecular weight of the deduced protein agreed well with that of the purified Ddc from the same insect. Data base search revealed significant and extesive sequence similarities among prokaryotic and eukaryotic PLP-dependent decarboxylases including Ceratitis capitata and bacterial histidine decarboxylase (HDC), strongly suggesting an ancient and common origin for all PLP-dependent decarboxylases. (C) 1997 Elsevier Science B.V

Purification from normal human plasma and biochemical characterization of a ribonuclease specific for poly(C) and poly(U)

A new specific ribonuclease from normal human plasma has been purified to homogeneity, following a five-step purification protocol that included DEAE-Sepharose, CM-Sepharose, and Heparin-Sepharose chromatographies. The purified enzyme was found to be glycosylated and appeared as a single 25-kDa band on a SDS polyacrylamide gel. This RNase is poly(C) preferential, degrading poly(U) at a lower rate. Activity of this RNase toward cleavage of native substrates such as ribosomal RNA was also detected. The human plasma ribonuclease is a thermolabile molecule, exhibiting maximum activity at pH 6.5. Comparison between other known plasma RNases and the human plasma ribonuclease described here indicated a variety of differences in their biochemical and catalytic properties. (C) 2003 Elsevier Science (USA). All rights reserved