Animal and Natural Resources Institute

Beltsville, MD, United States

Animal and Natural Resources Institute

Beltsville, MD, United States
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Dubey J.P.,Animal and Natural Resources Institute | Lago E.G.,Grande Rio University | Gennari S.M.,University of Sao Paulo | Su C.,University of Tennessee at Knoxville | Jones J.L.,Centers for Disease Control and Prevention
Parasitology | Year: 2012

Infections by the protozoan parasite Toxoplasma gondii are widely prevalent in humans and animals in Brazil. The burden of clinical toxoplasmosis in humans is considered to be very high. The high prevalence and encouragement of the Brazilian Government provides a unique opportunity for international groups to study the epidemiology and control of toxoplasmosis in Brazil. Many early papers on toxoplasmosis in Brazil were published in Portuguese and often not available to scientists in English-speaking countries. In the present paper we review prevalence, clinical spectrum, molecular epidemiology, and control of T. gondii in humans and animals in Brazil. This knowledge should be useful to biologists, public health workers, veterinarians, and physicians. Brazil has a very high rate of T. gondii infection in humans. Up to 50% of elementary school children and 50-80% of women of child-bearing age have antibodies to T. gondii. The risks for uninfected women to acquire toxoplasmosis during pregnancy and fetal transmission are high because the environment is highly contaminated with oocysts. The burden of toxoplasmosis in congenitally infected children is also very high. From limited data on screening of infants for T. gondii IgM at birth, 5-23 children are born infected per 10Å 000 live births in Brazil. Based on an estimate of 1 infected child per 1000 births, 2649 children with congenital toxoplasmosis are likely to be born annually in Brazil. Most of these infected children are likely to develop symptoms or signs of clinical toxoplasmosis. Among the congenitally infected children whose clinical data are described in this review, several died soon after birth, 35% had neurological disease including hydrocephalus, microcephaly and mental retardation, 80% had ocular lesions, and in one report 40% of children had hearing loss. The severity of clinical toxoplasmosis in Brazilian children may be associated with the genetic characteristics of T. gondii isolates prevailing in animals and humans in Brazil. © Cambridge University Press 2012.


Santin M.,Animal and Natural Resources Institute | Gomez-Munoz M.T.,Complutense University of Madrid | Solano-Aguilar G.,Beltsville Nutrition Research Center | Fayer R.,Animal and Natural Resources Institute
Parasitology Research | Year: 2011

Blastocystis spp. is commonly found in the feces of humans worldwide. Infection has been reported as asymptomatic, acute symptomatic, and chronic symptomatic. This wide range of responses to infection could be related to the genetic diversity of morphologically indistinguishable specimens obtained from infected hosts. The former name Blastocystis hominis is now reported as Blastocystis spp. because of its genetic diversity. Blastocystis is recognized as a complex of subtypes that have not been fully characterized as independent species. The finding of Blastocystis spp. in feces from several animal species suggests a zoonotic potential. Based on conserved regions of published nucleotide SSU rDNA sequences from all Blastocystis subtypes found in GenBank, a PCR and sequencing protocol was developed. The ~500 bp SSU rDNA gene fragment amplified by this PCR is highly sensitive compared with published primers and contains highly variable regions that allow phylogenetic analysis of Blastocystis. These primers were used to detect and subtype Blastocystis spp. specimens from naturally infected humans, primates, cattle, pigs, and chickens. Based on these findings, application of this method can elucidate the complexity of this heterogeneous genus and its role in human and animal disease, as well as its zoonotic potential. © 2011 Springer-Verlag (outside the USA).


Min W.,Gyeongsang National University | Kim W.H.,Gyeongsang National University | Lillehoj E.P.,University of Maryland, Baltimore | Lillehoj H.S.,Animal and Natural Resources Institute
Developmental and Comparative Immunology | Year: 2013

The molecular and cellular mechanisms leading to immune protection against coccidiosis are complex and include multiple aspects of innate and adaptive immunities. Innate immunity is mediated by various subpopulations of immune cells that recognize pathogen associated molecular patterns (PAMPs) through their pattern recognition receptors (PRRs) leading to the secretion of soluble factors with diverse functions. Adaptive immunity, which is important in conferring protection against subsequent reinfections, involves subtypes of T and B lymphocytes that mediate antigen-specific immune responses. Recently, global gene expression microarray analysis has been used in an attempt to dissect this complex network of immune cells and molecules during avian coccidiosis. These new studies emphasized the uniqueness of the innate immune response to Eimeria infection, and directly led to the discovery of previously uncharacterized host genes and proteins whose expression levels were modulated following parasite infection. Among these is the IL-17 family of cytokines. This review highlights recent progress in IL-17 research in the context of host immunity to avian coccidiosis. © 2013.


Li R.W.,Animal and Natural Resources Institute | Connor E.E.,Animal and Natural Resources Institute | Li C.,Animal and Natural Resources Institute | Baldwin Vi R.L.,Animal and Natural Resources Institute | And 2 more authors.
Environmental Microbiology | Year: 2012

The temporal sequence of microbial establishment in the rumen of the neonatal ruminant has important ecological and pathophysiological implications. In this study, we characterized the rumen microbiota of pre-ruminant calves fed milk replacer using two approaches, pyrosequencing of hypervariable V3-V5 regions of the 16S rRNA gene and whole-genome shotgun approach. Fifteen bacterial phyla were identified in the microbiota of pre-ruminant calves. Bacteroidetes was the predominant phylum in the rumen microbiota of 42-day-old calves, representing 74.8% of the 16S sequences, followed by Firmicutes (12.0%), Proteobacteria (10.4%), Verrucomicrobia (1.2%) and Synergistetes (1.1%). However, the phylum-level composition of 14-day-old calves was distinctly different. A total of 170 bacterial genera were identified while the core microbiome of pre-ruminant calves included 45 genera. Rumen development seemingly had a significant impact on microbial diversity. The dazzling functional diversity of the rumen microbiota was reflected by identification of 8298 Pfam and 3670 COG protein families. The rumen microbiota of pre-ruminant calves displayed a considerable compositional heterogeneity during early development. This is evidenced by a profound difference in rumen microbial composition between the two age groups. However, all functional classes between the two age groups had a remarkably similar assignment, suggesting that rumen microbial communities of pre-ruminant calves maintained a stable function and metabolic potentials while their phylogenetic composition fluctuated greatly. The presence of all major types of rumen microorganisms suggests that the rumen of pre-ruminant calves may not be rudimentary. Our results provide insight into rumen microbiota dynamics and will facilitate efforts in formulating optimal early-weaning strategies. © 2011.


Shin J.H.,Johns Hopkins University | Li R.W.,Animal and Natural Resources Institute | Gao Y.,Johns Hopkins University | Baldwin VI R.,Animal and Natural Resources Institute | Li C.-J.,Animal and Natural Resources Institute
Functional and Integrative Genomics | Year: 2012

Butyrate-induced histone acetylation plays an important role in the regulation of gene expression. However, the regulation mechanisms of histone modification remain largely unclear. To comprehensively analyze histone modification induced by butyrate, we utilized chromatin immunoprecipitation (ChIP) technology combined with next-generation sequencing technology (ChIP-seq) to analyze histone modification (acetylation) induced by butyrate and to map the epigenomic landscape of normal histone H3 and acetylated histone H3K9 and H3K27 on a large scale. To determine the location of histone H3, acetyl-H3K9, and acetyl-H3K27 binding sites within the bovine genome, we analyzed the H3-, acetyl-H3K9-, and acetyl-H3K27-enriched binding regions in the proximal promoter within 5 kb upstream, or at the 5′ untranslated region (UTR) from the transcriptional start site (TSS), exon, intron, and intergenic regions (defined as regions 25 kb upstream or 10 kb downstream from the TSS). Our analysis indicated that the distribution of histone H3, acetyl-H3K9, and acetyl-H3K27 correlated with transcription activity induced by butyrate. Using the GADEM algorithm, several motifs were generated for each of the ChIP-seq datasets. A de novo search for H3, acetyl-H3K9, and acetyl-H3K27 binding motifs indicated that histone modification (acetylation) at various locations changes the histone H3 binding preferences. Our results reveal that butyrate-induced acetylation in H3K9 and H3K27 changes the sequence-based binding preference of histone H3 and underlies the potential mechanisms of gene expression regulation induced by butyrate. © 2012 Springer-Verlag (outside the USA).


Liu Q.,Institute of Military Veterinary | Tuo W.,Animal and Natural Resources Institute | Gao H.,Institute of Military Veterinary | Zhu X.-Q.,Lanzhou Veterinary Research Institute
Parasitology Research | Year: 2010

MicroRNAs (miRNAs) are a class of endogenous non-coding small RNAs regulating gene expression in eukaryotes at the post-transcriptional level. The complex life cycles of parasites may require the ability to respond to environmental and developmental signals through miRNA-mediated gene expression. Over the past 17 years, thousands of miRNAs have been identified in the nematode Caenorhabditis elegans and other parasites. Here, we review the current status and potential functions of miRNAs in protozoan, helminths, and arthropods, and propose some perspectives for future studies. © 2010 Springer-Verlag.


Leary D.H.,U.S. Naval Academy | Hervey W.J.,U.S. Naval Academy | Li R.W.,Animal and Natural Resources Institute | Deschamps J.R.,Center for Bio Molecular Science and Engineering | And 2 more authors.
Analytical Chemistry | Year: 2012

The large-scale identification and quantitation of proteins via nanoliquid chromatography (LC)-tandem mass spectrometry (MS/MS) offers a unique opportunity to gain unprecedented insight into the microbial composition and biomolecular activity of true environmental samples. However, in order to realize this potential for marine biofilms, new methods of protein extraction must be developed as many compounds naturally present in biofilms are known to interfere with common proteomic manipulations and LC-MS/MS techniques. In this study, we used amino acid analyses (AAA) and LC-MS/MS to compare the efficacy of three sample preparation methods [6 M guanidine hydrochloride (GuHCl) protein extraction + in-solution digestion + 2D LC; sodium dodecyl sulfate (SDS) protein extraction + 1D gel LC; phenol protein extraction + 1D gel LC] for the metaproteomic analyses of an environmental marine biofilm. The AAA demonstrated that proteins constitute 1.24% of the biofilm wet weight and that the compared methods varied in their protein extraction efficiencies (0.85-15.15%). Subsequent LC-MS/MS analyses revealed that the GuHCl method resulted in the greatest number of proteins identified by one or more peptides whereas the phenol method provided the greatest sequence coverage of identified proteins. As expected, metagenomic sequencing of the same biofilm sample enabled the creation of a searchable database that increased the number of protein identifications by 48.7% (≥1 peptide) or 54.7% (≥2 peptides) when compared to SwissProt database identifications. Taken together, our results provide methods and evidence-based recommendations to consider for qualitative or quantitative biofilm metaproteome experimental design. © 2012 American Chemical Society.


Dubey J.P.,Animal and Natural Resources Institute | Yabsley M.J.,University of Georgia
Parasitology | Year: 2010

Certain species of the protozoan genus Besnoitia cause clinical disease in livestock and wildlife. In the present paper a new species, Besnoitia neotomofelis is described from the southern planes woodrat (Neotoma micropus). The parasite was detected by bioassay of woodrat tissues in outbred Swiss Webster mice in an attempt to isolate Toxoplasma gondii. Initially, the organism was misdiagnosed as T. gondii because it was highly pathogenic for mice and its tachyzoites resembled T. gondii tachyzoites. Further studies revealed that it differed structurally and biologically from T. gondii. Tachyzoites were successfully cultivated and maintained in vitro in bovine monocytes and African green monkey kidney cells, and in vivo in mice. Non-dividing, uninucleate tachyzoites were approximately 15 m in size. Longitudinally-cut bradyzoites in tissue sections measured 15-1677-93 m. Tissue cysts were microscopic, up to 210 m long, and were infective orally to mice. Cats fed tissue cysts shed unsporulated 1314 m sized oocysts. All mice inoculated with B. neotomofelis died of acute besnoitiosis, irrespective of the dose, and Norwegian rats became infected but remained asymptomatic. Entero-epithelial stages (schizonts, gamonts) were found in cats fed tissue cysts. Large (up to 4050 m) first-generation schizonts developed in the lamina propria of the small intestine of cats. A second generation of small sized (8 m) schizonts containing 4-8 merozoites was detected in enterocytes of the small intestine. Gamonts and oocysts were seen in goblet cells of the small intestinal epithelium. Tachyzoites were present in mesenteric lymph nodes of cats. Phylogenetic analysis indicated that B. neotomofelis was related to other Besnoitia species from rodents, rabbits, and opossums. Besnoitia neotomofelis is distinct from the 3 other species of Besnoitia, B. wallacei, B. darlingi and B. oryctofelisi that utilize cats as a definitive host. © Cambridge University Press 2010. This is a work of the U.S. Government and is not subject to copyright protection in the United States.


Richards M.P.,Animal and Natural Resources Institute | McMurtry J.P.,Animal and Natural Resources Institute
International Journal of Peptides | Year: 2010

To understand how the proghrelin system functions in regulating growth hormone release and food intake as well as defining its pleiotropic roles in such diverse physiological processes as energy homeostasis, gastrointestinal tract function and reproduction require detailed knowledge of the structure and function of the components that comprise this system. These include the preproghrelin gene that encodes the proghrelin precursor protein from which two peptide hormones, ghrelin and obestatin, are derived and the cognate receptors that bind proghrelin-derived peptides to mediate their physiological actions in different tissues. Also key to the functioning of this system is the posttranslational processing of the proghrelin precursor protein and the individual peptides derived from it. While this system has been intensively studied in a variety of animal species and humans over the last decade, there has been considerably less investigation of the avian proghrelin system which exhibits some unique differences compared to mammals. This review summarizes what is currently known about the proghrelin system in birds and offers new insights into the nature and function of this important endocrine system. Such information facilitates cross-species comparisons and contributes to our understanding of the evolution of the proghrelin system. Copyright © 2010 M. P. Richards and J. P. McMurtry.


Rosebrough R.W.,Animal and Natural Resources Institute | Russell B.A.,Animal and Natural Resources Institute | Richards M.P.,Animal and Natural Resources Institute
Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology | Year: 2011

This experiment was conducted to determine possible relationships between certain indices of lipid metabolism and specific gene expression in chickens fed graded levels of dietary crude protein. Male, broiler chickens (Gallus gallus) growing from 7 to 28. days of age were fed diets containing 12 or 30% protein ad libitum. Both groups were then switched to the diets containing the opposite level of protein. Birds were sampled at 0, 6, 9, 12, 18 and 24. h following the switch in protein levels. Measurements taken included in vitro lipogenesis (IVL), malic enzyme (ME), aspartate aminotransferase (AAT) and isocitrate dehydrogenase (NADP) (ICD) activities. In addition, ME, AAT, ICD, fatty acid synthase (FAS), and acetyl coenzyme carboxylase (ACC) gene expression rates were determined. IVL and ME activities were inversely related to dietary protein levels (12 to 30%) and to acute changes from 12 to 30%. In contrast, expression of ME, FAS and ACC genes was decreased by feeding a 30% protein diet (acute or chronic feeding). Results of the present study demonstrate a continued role for protein in the regulation of broiler metabolism. It should be pointed out; however, that metabolic regulation at the gene level only occurs when feeding very high or very low levels of dietary protein. © 2010.

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