The hookworm Necator americanus is the predominant soil-transmitted human parasite. Adult worms feed on blood in the small intestine, causing iron deficiency anaemia, malnutrition, growth and development stunting in children, and severe morbidity and mortality during pregnancy in women. Characterization of the first hookworm genome sequence (244 Mb, 19,151 genes) identified genes orchestrating the hookworm's invasion of the human host, genes involved in blood feeding and development, and genes encoding proteins that represent new potential drug targets against hookworms. N. americanus has undergone a considerable and unique expansion of immunomodulator proteins, some of which we highlight as potential novel treatments against inflammatory diseases. We also utilize a protein microarray to demonstrate a post-genomic application of the hookworm genome sequence. This genome provides an invaluable resource to boost ongoing efforts towards fundamental and applied post-genomic research, including the development of new methods to control hookworm and human immunological diseases.

Background Corynebacterium pseudotuberculosis, a Gram-positive, facultative intracellular pathogen, is the etiologic agent of the disease known as caseous lymphadenitis (CL). CL mainly affects small ruminants, such as goats and sheep; it also causes infections in humans, though rarely. This species is distributed worldwide, but it has the most serious economic impact in Oceania, Africa and South America. Although C. pseudotuberculosis causes major health and productivity problems for livestock, little is known about the molecular basis of its pathogenicity.Methodology and FindingsWe characterized two C. pseudotuberculosis genomes (Cp1002, isolated from goats; and CpC231, isolated from sheep). Analysis of the predicted genomes showed high similarity in genomic architecture, gene content and genetic order. When C. pseudotuberculosis was compared with other Corynebacterium species, it became evident that this pathogenic species has lost numerous genes, resulting in one of the smallest genomes in the genus. Other differences that could be part of the adaptation to pathogenicity include a lower GC content, of about 52%, and a reduced gene repertoire. The C. pseudotuberculosis genome also includes seven putative pathogenicity islands, which contain several classical virulence factors, including genes for fimbrial subunits, adhesion factors, iron uptake and secreted toxins. Additionally, all of the virulence factors in the islands have characteristics that indicate horizontal transfer.ConclusionsThese particular genome characteristics of C. pseudotuberculosis, as well as its acquired virulence factors in pathogenicity islands, provide evidence of its lifestyle and of the pathogenicity pathways used by this pathogen in the infection process. All genomes cited in this study are available in the NCBI Genbank database (http://www.ncbi.nlm.nih.gov/genbank/) under accession numbers CP001809 and CP001829.

BackgroundThe blood-feeding hookworm Necator americanus infects hundreds of millions of people worldwide. In order to elucidate fundamental molecular biological aspects of this hookworm, the transcriptome of the adult stage of Necator americanus was explored using next-generation sequencing and bioinformatic analyses.Methodology/Principal FindingsA total of 19,997 contigs were assembled from the sequence data; 6,771 of these contigs had known orthologues in the free-living nematode Caenorhabditis elegans, and most of them encoded proteins with WD40 repeats (10.6%), proteinase inhibitors (7.8%) or calcium-binding EF-hand proteins (6.7%). Bioinformatic analyses inferred that the C. elegans homologues are involved mainly in biological pathways linked to ribosome biogenesis (70%), oxidative phosphorylation (63%) and/or proteases (60%); most of these molecules were predicted to be involved in more than one biological pathway. Comparative analyses of the transcriptomes of N. americanus and the canine hookworm, Ancylostoma caninum, revealed qualitative and quantitative differences. For instance, proteinase inhibitors were inferred to be highly represented in the former species, whereas SCP/Tpx-1/Ag5/PR-1/Sc7 proteins ( = SCP/TAPS or Ancylostoma-secreted proteins) were predominant in the latter. In N. americanus, essential molecules were predicted using a combination of orthology mapping and functional data available for C. elegans. Further analyses allowed the prioritization of 18 predicted drug targets which did not have homologues in the human host. These candidate targets were inferred to be linked to mitochondrial (e.g., processing proteins) or amino acid metabolism (e.g., asparagine t-RNA synthetase).ConclusionsThis study has provided detailed insights into the transcriptome of the adult stage of N. americanus and examines similarities and differences between this species and A. caninum. Future efforts should focus on comparative transcriptomic and proteomic investigations of the other predominant human hookworm, A. duodenale, for both fundamental and applied purposes, including the prevalidation of anti-hookworm drug targets.

Background: Presence of tumor markers in serum might be connected to the number of secreting cells and with the stage of the neoplasm. However, there are few studies regarding these markers in veterinary clinical oncology.Objectives: To determine the serum concentrations of cancer antigen 15.3 (CA 15.3), carcinoembryonic antigen (CEA), and lactate dehydrogenase (LDH) in female dogs with different stages of mammary cancer.Animals: Ninety female dogs, including 30 that were healthy, 40 that had nonmetastatic cancer, 12 with regional metastasis, and 8 with distant lymph node metastasis.Methods: Prospective case-controlled observational study. Serum samples were collected to measure CA15.3, CEA, and LDH from 60 female dogs with mammary cancer during mastectomy and 30 healthy female dogs during routine check-up. CA15.3 and CEA were determined by chemiluminescent immunoassay and LDH by ultraviolet kinetic method. Western blotting analysis was performed to confirm the specificity and possible cross-reactivity of human CA15.3 and CEA antibodies with canine serum. Group data were compared by ANOVA followed by Student-Newman-Keuls and Tukey's tests. Correlations were investigated by Pearson and Spearman tests.Results: CEA, CA15.3, and LDH were measurable in all groups. Higher serum concentration of CA15.3 and LDH was associated with regional and distant metastases. There was a significantly higher serum CA15.3 concentration in animals with lymph node metastasis when compared with animals without metastasis. There were no significant differences in CEA among groups. Expression of CA15.3 and CEA in canine serum was confirmed by Western blotting.Conclusions and Clinical Importance: Serum CA15.3 can be used to distinguish nonmetastatic from metastatic carcinomas.

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