Genome analysis and comparative genomics of a Giardia intestinalis assemblage E isolate

<p>Abstract</p> <p>Background</p> <p><it>Giardia intestinalis </it>is a protozoan parasite that causes diarrhea in a wide range of mammalian species. To further understand the genetic diversity between the <it>Giardia intestinalis </it>species, we have performed genome sequencing and analysis of a wild-type <it>Giardia intestinalis </it>sample from the assemblage E group, isolated from a pig.</p> <p>Results</p> <p>We identified 5012 protein coding genes, the majority of which are conserved compared to the previously sequenced genomes of the WB and GS strains in terms of microsynteny and sequence identity. Despite this, there is an unexpectedly large number of chromosomal rearrangements and several smaller structural changes that are present in all chromosomes. Novel members of the VSP, NEK Kinase and HCMP gene families were identified, which may reveal possible mechanisms for host specificity and new avenues for antigenic variation. We used comparative genomics of the three diverse <it>Giardia intestinalis </it>isolates P15, GS and WB to define a core proteome for this species complex and to identify lineage-specific genes. Extensive analyses of polymorphisms in the core proteome of <it>Giardia </it>revealed differential rates of divergence among cellular processes.</p> <p>Conclusions</p> <p>Our results indicate that despite a well conserved core of genes there is significant genome variation between <it>Giardia </it>isolates, both in terms of gene content, gene polymorphisms, structural chromosomal variations and surface molecule repertoires. This study improves the annotation of the <it>Giardia </it>genomes and enables the identification of functionally important variation.</p

Optimal control of Aedes aegypti mosquitoes by the sterile insect technique and insecticide

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)We present a mathematical model to describe the dynamics of mosquito population when sterile male mosquitoes (produced by irradiation) are introduced as a biological control, besides the application of insecticide. In order to analyze the minimal effort to reduce the fertile female mosquitoes, we search for the optimal control considering the cost of insecticide application, the cost of the production of irradiated mosquitoes and their delivery as well as the social cost (proportional to the number of fertilized females mosquitoes). The optimal control is obtained by applying the Pontryagin's Maximum Principle. (C) 2009 Elsevier Inc. All rights reserved.22311223Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)PAPIIT-UNAM [IN108607-3]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [04/07075-7]CNPq [302108/2008-4]PAPIIT-UNAM [IN108607-3

Prevalence and genotyping of Giardia in husbandry systems in Taiwan.

[[abstract]]In this study, 107 fecal specimens were collected from 40 sampling sites in Taiwan livestock and avian farms to test for Giardia cysts. Enzyme-linked immunosorbent assay (ELISA) and immunofluorescent microscopic examination were performed as a presumption test and confirmation test, respectively. Eight out of 107 samples analyzed by ELISA showed the presence of Giardia, among which six samples were confirmed by immunofluorescent microscopic examination, and four samples were reconfirmed by polymerase chain reaction method. Giardia species were identified by nucleic acid sequencing method of beta-giardin gene. Two Giardia duodenalis assemblage A isolates and E isolates were all detected from cattle feces. This is the first identification of genotypes of G. duodenalis in the feces of feeding animals in Taiwan