WorldWideScience

Sample records for experimentally infected specific

  1. Host specificity of North American Rhabdias spp. (Nematoda: Rhabdiasidae): combining field data and experimental infections with a molecular phylogeny.

    Science.gov (United States)

    Langford, Gabriel J; Janovy, John

    2013-04-01

    Lungworms of the cosmopolitan genus Rhabdias are among the most common parasites of amphibians and squamate reptiles. The present study used experimental infections, field studies, and a molecular phylogeny to determine the host specificity of 6 Rhabdias spp. that infect snakes and anurans from North America. The molecular phylogeny suggests Rhabdias ranae from Nebraska and Mississippi may represent separate, cryptic species. In addition, the phylogeny strongly supports separate clades for anuran and snake lungworms. Field studies and experimental infections indicate that snake lungworms are generalist snake parasites; however, laboratory experiments also suggest that lizards can be infected under some environmental conditions. Lungworms from anurans were found not to infect salamanders or reptiles, in nature or in the laboratory; anuran lungworm species ranged from strict host specificity, e.g., R. ranae from Nebraska, to relative generalist, e.g., Rhabdias joaquinensis from Nebraska. Overall, host specificity for species of Rhabdias does not provide support for the evolution of progressive specialization over time. For most species of lungworms, host specificity in nature appears to be limited by both ecological and physiological factors, which vary between species and their hosts. Furthermore, some lungworms, e.g., Rhabdias bakeri from Missouri, appear to be tracking host resources instead of host phylogenies, an example of ecological fitting.

  2. Flow Cytometric Detection of Mycobacterium avium subsp. paratuberculosis-Specific Antibodies in Experimentally Infected and Naturally Exposed Calves

    Science.gov (United States)

    Bridger, P. S.; Bulun, H.; Fischer, M.; Akineden, Ö.; Seeger, T.; Barth, S.; Henrich, M.; Doll, K.; Bülte, M.; Menge, C.; Bauerfeind, R.

    2013-01-01

    A desirable test to diagnose infections with Mycobacterium avium subsp. paratuberculosis facilitates identification of infected cattle prior to the state of M. avium subsp. paratuberculosis shedding. This study aimed at adjusting a flow cytometry (FC)-based assay, using intact M. avium subsp. paratuberculosis bacteria as the antigen, for diagnosis of M. avium subsp. paratuberculosis infections in calves. Serum samples were collected from experimentally infected (n = 12) and naturally exposed (n = 32) calves. Samples from five calves from positive dams were analyzed to determine the dynamics of maternal antibodies. Samples from adult cattle with defined infection status served as the standard (18 M. avium subsp. paratuberculosis shedders, 22 M. avium subsp. paratuberculosis free). After preadsorption with Mycobacterium phlei, sera were incubated with M. avium subsp. paratuberculosis and M. avium subsp. avium bacterial suspensions, respectively, followed by the separate detection of bovine IgG, IgG1, IgG2, and IgM attached to the bacterial surface. M. avium subsp. paratuberculosis-specific sample/positive (S/P) ratios were compared to enzyme-linked immunosorbent assay (ELISA) S/P ratios. In adult cattle, the FC assay for IgG1 had a sensitivity of 78% at a specificity of 100%. Maternally acquired antibodies could be detected in calves up to 121 days of life. While all but two sera taken at day 100 ± 10 postnatum from naturally exposed calves tested negative, elevated S/P ratios (IgG and IgG1) became detectable from 44 and 46 weeks postinoculation onwards in two calves infected experimentally. Even with the optimized FC assay, M. avium subsp. paratuberculosis-specific antibodies can only occasionally be detected in infected calves less than 12 months of age. The failure to detect such antibodies apparently reflects the distinct immunobiology of M. avium subsp. paratuberculosis infections rather than methodological constraints. PMID:23885032

  3. Pre-infection frequencies of equine herpesvirus-1 specific, cytotoxic T lymphocytes correlate with protection against abortion following experimental infection of pregnant mares.

    Science.gov (United States)

    Kydd, J H; Wattrang, E; Hannant, D

    2003-12-15

    In general, vaccines containing inactivated equine herpesvirus-1 (EHV-1) fail to prevent abortion in pregnant mares following infection with a virulent strain of EHV-1. We have tested the hypothesis that resistance to EHV-1-induced abortion in pregnant mares is associated with high frequencies of EHV-1 specific, major histocompatibility complex (MHC) class I-restricted, cytotoxic T lymphocytes (CTL) in the circulation. To test this theory, three groups of pregnant mares were assembled with varying backgrounds of infection or vaccination in an attempt to mimic the immune status of the general population. Group 1 mares (n=9) were untreated controls selected at random. Group 2 mares (n=5) were vaccinated three times intramuscularly with inactivated EHV-1. Group 3 mares (n=3) had been infected with EHV-1 on four previous occasions. The frequency of CTL in blood leucocytes was measured by limiting dilution analysis at three time points; at the beginning of pregnancy (approximately 28 weeks before infection) in the Group 2 and Group 3 mares (4-7 weeks of gestation) (Group 1 was unavailable for sampling) and then 2 weeks before (30-40 weeks of gestation) and 3 weeks after experimental infection in all the mares. Serum samples were collected to monitor complement fixing (CF) antibody titres. Mares in all three groups were infected experimentally with EHV-1 strain Ab4/8 by the intranasal route after which they were monitored clinically to determine the outcome of pregnancy and samples were collected to determine the duration of nasopharyngeal shedding and cell-associated viraemia. The untreated control mares showed low pre-infection CTL. After experimental infection, they all seroconverted, aborted and demonstrated expected clinical and virological signs. Some vaccinated mares (3/5) had elevated titres of CF antibody prior to their first vaccination. All the vaccinated mares seroconverted after vaccination and exhibited higher CTL frequencies than controls before infection

  4. Detection of Neospora from tissues of experimentally infected rhesus macaques by PCR and specific DNA probe hybridization.

    Science.gov (United States)

    Ho, M S; Barr, B C; Tarantal, A F; Lai, L T; Hendrickx, A G; Marsh, A E; Sverlow, K W; Packham, A E; Conrad, P A

    1997-07-01

    Neospora is a newly recognized Toxoplasma-like cyst-forming coccidian parasite that causes abortion or congenital infections in naturally or experimentally infected animals. In this study, pregnant rhesus macaques were inoculated with culture-derived tachyzoites of a bovine Neospora isolate, and tissue samples from various major organs were collected from dams and fetuses for the detection of parasite DNA by using oligonucleotide primers COC-1 and COC-2 for PCR amplification of a conserved coccidial nuclear small-subunit rRNA gene sequence, and amplification products were confirmed by hybridization with a Neospora-specific DNA probe. PCR products were amplified from DNAs of different fetal monkey tissues, including brain, heart, lung, liver, spleen, skeletal muscle, skin, and placenta. In addition, Neospora DNA was amplified from the brain, heart, and lung tissues of infected rhesus macaque dams. The PCR and probe hybridization system may provide an effective method for the detection of Neospora infection in fetuses and dams from nonhuman primates and may be useful in determining the zoonotic potential of Neospora.

  5. Evaluation of the efficacy of a specific hyperimmune serum in experimental influenza infection in mice.

    Science.gov (United States)

    Marinescu, Bogdan; Coman, Cristin; Iancu, Adina Daniela; Stavaru, Crina; Lupulescu, Emilia; Onu, Adrian; Radu, Dorel Lucian

    2009-01-01

    Serotherapy still remains a way of treatment in some diseases, and it could be consider superior to any other mode of action because the protecting substances of the body are the products of the organism itself. The aim of the study was to establish an "in vivo" method for testing the efficacy of therapeutic serum. Hyperimmune serum for influenza A/PR8/34 viral strain, was prepared in sheep, and tested for inhibition of haemagglutination and microneutralisation. Seroprotection was evaluated in mice one day after being challenged with a lethal dose of the same virus. Our study shows that protection occurred in all mice treated with undiluted hyperimmune serum one day post infection (no clinical signs, faster recovery of the body weight after the first three days of the infection, all mice survived).

  6. The time course of the specific antibody response by various ELISAs in pigs experimentally infected with Toxoplasma gondii

    DEFF Research Database (Denmark)

    Lind, Peter; Haugegaard, J.; Wingstrand, Anne

    1997-01-01

    ELISA for IgM; (4) a reverse, antibody-catching IgM-ELISA. Groups of pigs (number between 6 and 10) were inoculated with tachyzoites of the RH-strain, tissue cysts of two complete strains, or oocysts in two doses (10(3) and 10(4)). All inoculations were tolerated well. Irrespective of strain and stage...... used for inoculation, specific IgG and anti-P-30 blocking activity appeared after 1-2 weeks, with OD-values stabilizing after 3-6 weeks and persisting throughout the study period (3-4 months). Specific IgM appeared quickly, but was short-lived (approximately weeks). A cut-off OD-value of 0....... Corresponding figures for the blocking ELISA were 37% inhibition as cut-off, with sensitivity and specificity of 0.94 and 0.94, respectively. Sera from a total of 87 pigs, experimentally infected with bacteria of the genera Salmonella, Yersinia or Actinobacillus and with the parasites Isospora suis, Trichinella...

  7. Determination of specific anti-leptospiral immunoglobulins M and G in sera of experimentally infected dogs by solid-phase enzyme-linked immunosorbent assay

    NARCIS (Netherlands)

    Frik, J.F.; Hartman, E.G.; Houten, M. van; Donk, J.A. van der

    1984-01-01

    The development and evaluation of an enzyme-linked immunosorbent assay (ELISA) to detect specific anti-leptospiral IgM and IgG in sera of dogs experimentally infected with Leptospira interrogans serotype canicola are reported. In all dogs specific anti-leptospiral IgM was detected from the second

  8. Experimental infection of specific pathogen-free pigs with Campylobacter: excretion in faeces and transmission to non-inoculated pigs.

    Science.gov (United States)

    Leblanc Maridor, Mily; Denis, Martine; Lalande, Françoise; Beaurepaire, Bernard; Cariolet, Roland; Fravalo, Philippe; Federighi, Michel; Seegers, Henri; Belloc, Catherine

    2008-10-15

    Campylobacter species are leading agents of human bacterial gastroenteritis and consumption of food of animal origin is a major source of infection. Although pigs are known to frequently exhibit high counts of Campylobacter in their faeces, more information is needed about the dynamics of this excretion. An experimental trial was conducted to evaluate the faecal excretion of Campylobacter by 7-week-old specific pathogen-free piglets inoculated per os with three Campylobacter strains (one C. coli isolated from a pig, one C. coli and one C. jejuni from chickens) alone or simultaneously (5x10(7)CFU/strain). Non-inoculated pigs were housed in adjacent pens. Pigs were monitored for 80 days for clinical signs and by bacteriological analysis of faeces. Pigs inoculated with porcine C. coli or with a mix of the three strains excreted from 10(3) to 10(6)CFU/g of faeces with a slight decrease at the end of the trial. Animals inoculated with poultry C. coli or C. jejuni strain excreted a lower quantity and some of them stopped excreting. At the end of the trial, only C. coli was detected in the faeces of pigs inoculated simultaneously with the three bacteria. Moreover, the transmission of Campylobacter was noticed between pens for the two C. coli strains and all the neighbouring animals became shedders with a level of excretion similar to the inoculated pigs. Intermittence in the Campylobacter excretion was also observed. Finally, our study highlighted a host preference of Campylobacter, namely C. coli seems to have a higher colonization potential for pigs than C. jejuni.

  9. Detection of infectious bursal disease virus in various lymphoid tissues of experimentally infected specific pathogen free chickens by different reverse transcription polymerase chain reaction assays

    DEFF Research Database (Denmark)

    Kabell, Susanne; Handberg, Kurt; Kusk, Mette

    2005-01-01

    transcription polymerase chain reaction (RT-PCR) assays, including two recently developed strain-specific assays, were employed for detection of ribonucleic acid (RNA) from three different IBDV strains in bursa tissue samples from experimentally infected specific pathogen free chickens. The virus strains...... included vaccine strain D78, classical strain Faragher 52/70, and the very virulent Danish strain DK01 The presence of the virus infection was confirmed by histopathologic evaluation of bursa lesions. The largest number of positive samples was obtained with a strain-specific two-step multiplex (MPX) RT...... of the IBDV strains used were detected in bursa tissues, whereas only the two virulent strains were detected in bone marrow, spleen, and thymus....

  10. Experimental Toxoplasma gondii infections in pigs: Humoral immune response, estimation of specific IgG avidity and the challenges of reproducing vertical transmission in sows.

    Science.gov (United States)

    Basso, Walter; Grimm, Felix; Ruetten, Maja; Djokic, Vitomir; Blaga, Radu; Sidler, Xaver; Deplazes, Peter

    2017-03-15

    Ten pregnant sows were experimentally inoculated per os with T. gondii in order to investigate vertical and galactogenic transmission of the parasite and the evolution and maturation of the specific IgG humoral response in the sows and piglets. Five seronegative sows received 10(4)T. gondii (CZ isolate clone H3) sporulated oocysts during late-pregnancy (Exp. 1), three sows received 10(4) oocysts during mid-pregnancy (Exp. 2) and three sows from Exp. 1 (and two seronegative sows) were re-inoculated with 10(5) oocysts during a further pregnancy (late-pregnancy) (Exp. 3). Besides, six 4.5 week-old piglets inoculated per os with 5×10(3) oocysts were also included in the serological investigations. All animals seroconverted (PrioCHECK Toxoplasma Ab porcine ELISA, Prionics, Switzerland) by 2-3 weeks post inoculation (wpi) and remained seropositive for at least 38 weeks or until euthanasia. Four chronically infected sows from Exp. 1 and 2 were serologically monitored during a further pregnancy and no reactivation, but a decrease of the antibody levels was observed at farrowing (Exp. 4). In all experiments, the specific IgG-avidity was initially low, increased during the course of infection and after re-inoculations. An avidity index (AI) ≥40% could be used to rule out recent infections (toxoplasmosis in pigs are still unknown. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Experimental Infection of Sheep using Infective Larvae (L3 ...

    African Journals Online (AJOL)

    Experimental Infection of Sheep using Infective Larvae (L3) harvested from the Faeces of Naturally Infected Swayne's Hartebeest ( Alcelaphus buselaphus swaynei ) at Senkele Swayne's Hartebeest Sanctuary, Ethiopia.

  12. Experimental Campylobacter Jejuni Infection in Humans

    Science.gov (United States)

    1988-03-01

    Blaser MJI Black RE. Duncan DJ, Amer I. Campylobacter Clements ML, Robins-Brone R, Lim Y-L. Duration of jejuni -specific serum antibodies are elevated in...SUBTITLE 5 FUNDING •4UMBERS Experimental Campylobacter jejuni Infection 86PP6826 in Humans 61102A 30161102BS13 AB6. AUTHOR(S)DA328 Robert E. Black...SUPPLEMENTARY NOTES Contract Title: Studies of the Outer Membrane Proteins of Campylobacter Jejuni for Vaccine Development ൔa• DISTRIBUTION

  13. Experimental Trichomonas infection: Morphological aspects

    Directory of Open Access Journals (Sweden)

    E. N. Shumkova

    2016-01-01

    Full Text Available Background. Growth tendency the asymptomatic forms of an urogenital trichomoniasis, frequency of complications from reproductive organs, uncertainty of many aspects of the violations of a spermatogenesis influencing reproductive function all this proves need of search of the urogenital trichomoniasis adequate experimental model. Lack of the corresponding experimental model is limited by our opportunities for carrying out the standardized, controlled researches on studying of transmission, pathogenesis, the immune answer, therapy and development of vaccines at a triсhomonas infection.Objective is studying action of Trichomonas vaginalis on a spermatogenny epithelium the mature of individuals of guinea pigs in the conditions of sharp and chronic experience.Materials and methods. Experiments are made on the “Reproductive System (Guinea Pigs + Trichomonas vaginalis” modeling the natural course of an infection. In experiment 2 groups of animals: 1st (n = 8 – experimental, 2nd (n = 8 – control were formed. Against the background of the reduction of the immune status (hydrocortisone 125 mg/kg intramuscularly 1 time in day during 2 days the animals of the 1st group were injected intraurethral suspension containing 1 × 106 Trichomonas on 0.5 ml of culture medium, the animals of the 2nd group – 0.5 ml of medium. Under the condition of the acute experiment the animals were sacrificed on day 9 (the middle of the cycle of spermatogenesis – I experienced group and on day 30 (full spermatogenic cycle – II experimental group. The control animals were slaughtered in the same period. The material for histological study was prepared by the traditional way.Results. In an experimental model of “Reproductive system (guinea pigs + T. vaginalis”, staging and degree of disturbance of spermatogenesis, depending on the duration of trichomonas infection were shown. So, in acute experience morphological changes correspond to changes in the

  14. Experimental Ascaris suum infection in Yankasa lambs ...

    African Journals Online (AJOL)

    The effects of experimental Ascaris suum infection in Yankasa lambs were investigated. Twenty four (24) Yankasa lambs aged 6-8 months were purchased and randomly divided into two groups (1 and 2). The lambs in group 1, consisting of 16 animals, were orally infected with 1500 infective A. suum eggs daily for seven ...

  15. Rhinovirus genome evolution during experimental human infection.

    Directory of Open Access Journals (Sweden)

    Samuel Cordey

    Full Text Available Human rhinoviruses (HRVs evolve rapidly due in part to their error-prone RNA polymerase. Knowledge of the diversity of HRV populations emerging during the course of a natural infection is essential and represents a basis for the design of future potential vaccines and antiviral drugs. To evaluate HRV evolution in humans, nasal wash samples were collected daily for five days from 15 immunocompetent volunteers experimentally infected with a reference stock of HRV-39. In parallel, HeLa-OH cells were inoculated to compare HRV evolution in vitro. Nasal wash in vivo assessed by real-time PCR showed a viral load that peaked at 48-72 h. Ultra-deep sequencing was used to compare the low-frequency mutation populations present in the HRV-39 inoculum in two human subjects and one HeLa-OH supernatant collected 5 days post-infection. The analysis revealed hypervariable mutation locations in VP2, VP3, VP1, 2C and 3C genes and conserved regions in VP4, 2A, 2B, 3A, 3B and 3D genes. These results were confirmed by classical sequencing of additional samples, both from inoculated volunteers and independent cell infections, and suggest that HRV inter-host transmission is not associated with a strong bottleneck effect. A specific analysis of the VP1 capsid gene of 15 human cases confirmed the high mutation incidence in this capsid region, but not in the antiviral drug-binding pocket. We could also estimate a mutation frequency in vivo of 3.4x10(-4 mutations/nucleotides and 3.1x10(-4 over the entire ORF and VP1 gene, respectively. In vivo, HRV generate new variants rapidly during the course of an acute infection due to mutations that accumulate in hot spot regions located at the capsid level, as well as in 2C and 3C genes.

  16. PMWS: Experimental model and co-infections

    DEFF Research Database (Denmark)

    Allan, G. M.; McNeilly, F.; Ellis, J

    2004-01-01

    and pneumonia and typical histological lesions include lymphocytic depletion and multinucleated giant cell formation in lymph nodes, degeneration and necrosis of hepatocytes, and multifocal lymphohistocytic interstitial pneumonia. This communication will review the results of experimental infections...

  17. Comparative haematological changes in experimentally infected ...

    African Journals Online (AJOL)

    A comparative study of haematological changes in Savannah brown goats experimentally infected with Trypanosoma brucei and Trypanosoma vivax was carried out using thirty (30) goats aged between 20 and 48 months and average weight of 13.00 kg. The parameters determined before and after infection included ...

  18. Blood biochemistry responses of chickens experimentally infected ...

    African Journals Online (AJOL)

    This study investigated the blood biochemistry responses of cockerels experimentally infected with a velogenic Newcastle disease virus (NDV) strain, KUDU 113. One hundred Isa white cockerels were used for the study. The cockerels were obtained at day-old and randomly divided into groups A- vaccinated and infected, ...

  19. An experimental Schistosoma mattheei infection in man.

    Science.gov (United States)

    Wolmarans, C T; de Kock, K N; van der Walt, M P

    1990-12-01

    Certain aspects of the immune response of a male experimentally infected with 3-day old cercariae of a pure field strain of Schistosoma matheei were investigated. Among others, aspects such as the reaction of eosinophils, neutrophils and blood platelets after infection, were included in the study. The involvement of IgG and the cross reaction between these antibodies and S. haematobium and S. mansoni were also investigated. The phenomenon that the cercariae were, 3 days after shedding, still capable of penetrating the skin causing an inflammatory response was studied. The results lend some support to the surmise that a pure S. mattheei infection in humans is incapable of any egg production.

  20. Experimental Proteus mirabilis Burn Surface Infection

    Science.gov (United States)

    1982-02-01

    mirabilis Burn Surface Infection Albert T. McManus, PhD; Charles G. McLeod, Jr, DVM; Arthur D. Mason, Jr, MD * We established a human burn Isolate of...William J1. Northam. Peter A. lDorsaneo, and Paulette langlinais MS. model may be useful in evaluation of experimental antibi - prov ided technical support

  1. Experimental Salmonella typhimurium infections in rats. I

    DEFF Research Database (Denmark)

    Hougen, H P; Jensen, E T; Klausen, B

    1989-01-01

    The course of experimentally induced Salmonella typhimurium infection was studied in three groups of inbred LEW rats: homozygous +/+, athymic rnu/rnu and isogeneic thymus-grafted rnu/rnu rats. In the first experiment the animals were inoculated intraperitoneally with 10(8) bacteria and all animals...

  2. Experimental Ascaris suum infection in Yankasa lambs ...

    African Journals Online (AJOL)

    aliyu.jibril

    2017-04-11

    Apr 11, 2017 ... Experimental Ascaris suum infection in Yankasa lambs: Parasitological and pathological observations. I Isah. 1. *, JO Ajanusi. 1. , NP Chiezey. 2. , LB Tekdek. 3. & B Mohammed. 4. 1. Department of Veterinary Parasitology and Entomology, Faculty of Veterinary Medicine,. Ahmadu Bello University, Zaria, ...

  3. Nonlinear hierarchical modeling of experimental infection data.

    Science.gov (United States)

    Singleton, Michael D; Breheny, Patrick J

    2016-08-01

    In this paper, we propose a nonlinear hierarchical model (NLHM) for analyzing longitudinal experimental infection (EI) data. The NLHM offers several improvements over commonly used alternatives such as repeated measures analysis of variance (RM-ANOVA) and the linear mixed model (LMM). It enables comparison of relevant biological properties of the course of infection including peak intensity, duration and time to peak, rather than simply comparing mean responses at each observation time. We illustrate the practical benefits of this model and the insights it yields using data from experimental infection studies on equine arteritis virus. Finally, we demonstrate via simulation studies that the NLHM substantially reduces bias and improves the power to detect differences in relevant features of the infection response between two populations. For example, to detect a 20% difference in response duration between two groups (n=15) in which the peak time and peak intensity were identical, the RM-ANOVA test had a power of just 11%, and LMM a power of just 12%. By comparison, the nonlinear model we propose had a power of 58% in the same scenario, while controlling the Type I error rate better than the other two methods. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. CD36 deficiency attenuates experimental mycobacterial infection

    Directory of Open Access Journals (Sweden)

    Min-Oo Gundula

    2010-10-01

    Full Text Available Abstract Background Members of the CD36 scavenger receptor family have been implicated as sensors of microbial products that mediate phagocytosis and inflammation in response to a broad range of pathogens. We investigated the role of CD36 in host response to mycobacterial infection. Methods Experimental Mycobacterium bovis Bacillus Calmette-Guérin (BCG infection in Cd36+/+ and Cd36-/- mice, and in vitro co-cultivation of M. tuberculosis, BCG and M. marinum with Cd36+/+ and Cd36-/-murine macrophages. Results Using an in vivo model of BCG infection in Cd36+/+ and Cd36-/- mice, we found that mycobacterial burden in liver and spleen is reduced (83% lower peak splenic colony forming units, p Cd36-/- animals. Intracellular growth of all three mycobacterial species was reduced in Cd36-/- relative to wild type Cd36+/+ macrophages in vitro. This difference was not attributable to alterations in mycobacterial uptake, macrophage viability, rate of macrophage apoptosis, production of reactive oxygen and/or nitrogen species, TNF or interleukin-10. Using an in vitro model designed to recapitulate cellular events implicated in mycobacterial infection and dissemination in vivo (i.e., phagocytosis of apoptotic macrophages containing mycobacteria, we demonstrated reduced recovery of viable mycobacteria within Cd36-/- macrophages. Conclusions Together, these data indicate that CD36 deficiency confers resistance to mycobacterial infection. This observation is best explained by reduced intracellular survival of mycobacteria in the Cd36-/- macrophage and a role for CD36 in the cellular events involved in granuloma formation that promote early bacterial expansion and dissemination.

  5. Formal specification is an experimental science

    Energy Technology Data Exchange (ETDEWEB)

    Bjorner, D. [Technical Univ., Lyngby (Denmark)

    1992-09-01

    Traditionally, abstract models of large, complex systems have been given in free-form mathematics, combining - often in ad-hoc, not formally supported ways - notions from the disciplines of partial differential equations, functional analysis, mathematical statistics, etc. Such models have been very useful for assimilation of information, analysis (investigation), and prediction (simulation). These models have, however, usually not been helpful in deriving computer representations of the modelled systems - for the purposes of computerized monitoring and control, Computing science, concerned with how to construct objects that can exist within the computer, offers ways of complementing, and in some cases, replacing or combining traditional mathematical models. Formal, model-, as well as property-oriented, specifications in the styles of denotational (respectively, algebraic semantics) represent major approaches to such modelling. In this expository, discursive paper we illustrate what we mean by model-oriented specifications of large, complex technological computing systems. The three modelling examples covers the introvert programming methodological subject of SDEs: software development environments, the distributed computing system subject of wfs`s: (transaction) work flow systems, and the extrovert subject of robots: robotics! the thesis is, just as for mathematical modelling, that we can derive much understanding, etc., from experimentally creating such formally specified models - on paper - and that we gain little in additionally building ad-hoc prototypes. Our models are expressed in a model-oriented style using the VDM specification language Meta-IV In this paper the models only reflect the {open_quotes}data modelling{close_quotes} aspects. We observe that such data models are more easily captured in the model-oriented siyle than in the algebraic semantics property-oriented style which originally was built of the abstraction of operations. 101 refs., 4 figs.

  6. Co-incubation with IL-18 potentiates antigen-specific IFN-γ response in a whole-blood stimulation assay for measurement of cell-mediated immune responses in pigs experimentally infected with Lawsonia intracellularis

    DEFF Research Database (Denmark)

    Riber, Ulla; Boesen, Henriette Toft; Jakobsen, Jeanne Toft

    2011-01-01

    The whole-blood interferon-gamma (IFN-γ) assay is a quantitative in-vitro assay for a direct read out of Ag-specific cell-mediated immune (CMI) responses to infectious diseases. The IFN-γ assay is robust in severe intracellular infections like Brucella or mycobacteria, but more difficult to evalu......The whole-blood interferon-gamma (IFN-γ) assay is a quantitative in-vitro assay for a direct read out of Ag-specific cell-mediated immune (CMI) responses to infectious diseases. The IFN-γ assay is robust in severe intracellular infections like Brucella or mycobacteria, but more difficult...

  7. The pathology observed in experimental Fasciola gigantica infected ...

    African Journals Online (AJOL)

    Pathological lesions were observed in four Fasciola gigantica infected Yankasa sheep that died at the 10th, 11th and 12th week post-infection in an experimental infection at the Reproduction unit of the National Animal production Research institute, Shika-Zaria, Nigeria. The experiment involved twelve Yankasa sheep that ...

  8. PLASMODIUM BERGHEI: CYCLICAL TRANSMISSIONS BY EXPERIMENTALLY INFECTED ANOPHELES QUADRIMACULATUS.

    Science.gov (United States)

    YOELI, M; MOST, H; BONE, G

    1964-06-26

    A number of strains of Plasmodium berghei were isolated from sporozoites of Anopheles dureni. Laboratory-bred Anopheles quadrimaculatus fed on carriers of the newly isolated strains showed overwhelming midgut infections and moderate or mild salivary gland infections. Successive cyclic transmissions by the bite of experimentally infected A. quadrimaculatus in laboratorybred tree rats (Thamnomys surdaster) were carried out.

  9. Neospora caninum infection in birds: experimental infections in chicken and embryonated eggs.

    Science.gov (United States)

    Furuta, P I; Mineo, T W P; Carrasco, A O T; Godoy, G S; Pinto, A A; Machado, R Z

    2007-12-01

    Neospora caninum causes economical impact in cattle-raising farms since it is implicated as the major cause of bovine abortions. Although infection by the parasite has been widely described in mammals, the role of birds in its life-cycle is still obscure. Therefore, this work aimed to evaluate the infection by N. caninum in different chicken models. Experimental infections were conducted in 7-day-old chicks, laying hens and embryonated eggs, where samples were analysed for parasite burden, IgG antibodies and lesions promoted. Chickens demonstrated an asymptomatic infection, although with seroconversion and systemic replication of the parasite. In laying hens, no signs of vertical transmission were observed. However, embryonated eggs inoculated by the allantoic cavity route demonstrated susceptibility to infection, with mortality rates around 50% independent of the inoculum dose. Additionally, dogs became infected after ingestion of different amounts of inoculated eggs, producing either oocysts or specific IgG antibodies. The results herein presented demonstrate that chickens may be intermediate hosts of N. caninum and that embryonated eggs could be a useful model to study the parasite's biology.

  10. Persistence of specific antibody response in different experimental infections of mice with Toxocara canis larvae Persistência da resposta humoral em camundongos experimentalmente infectados com larvas de Toxocara canis

    Directory of Open Access Journals (Sweden)

    Pedro Paulo Chieffi

    1995-06-01

    Full Text Available Anti-Toxocara antibody production and persistence were studied in experimental infections of BALB/c mice, according to three different schedules: Group I (GI - 25 mice infected with 200 T. canis eggs in a single dose; Group II (GII 25 mice infected with 150 T. canis eggs given in three occasions, 50 in the 1st, 50 in the 5th and 50 in the 8th days; Group III (GIII - 25 mice also infected with 150 T. canis eggs, in three 50 eggs portions given in the 1st, 14th and 28th days. A 15 mice control group (GIV was maintained without infection. In the 30th, 50th, 60th, 75th, 105th and 180th post-infection days three mice of the GI, GII and GIII groups and two mice of the control group had been sacrificed and exsanguinated for sera obtention. In the 360th day the remainder mice of the four groups were, in the same way, killed and processed. The obtained sera were searched for the presence of anti-Toxocara antibodies by an ELISA technique, using T. canis larvae excretion-secretion antigen. In the GI and GII, but not in the GIII, anti-Toxocara antibodies had been found, at least, up to the 180th post-infection day. The GIII only showed anti-Toxocara antibodies, at significant level, in the 30th post-infection day.Estudou-se a cinética de anticorpos anti-Toxocara em camundongos BALB/c infectados experimentalmente segundo três esquemas: Grupo I (GI: 25 camundongos infectados com dose única de 200 ovos embrionados de T. canis; grupo II (GII: 25 camundongos infectados com 150 ovos embrionados de T. canis, divididos em três doses de 50 ovos, administrados no 1º, 5º e 8º dias; Grupo III (GIII: 25 camundongos infectados com 150 ovos embrionados de T. canis, administrados em três doses de 50 ovos no 1º, 14º e 28º dias. Um grupo de 15 camundongos foi mantido nas mesmas condições, porém sem infecção, constituindo o grupo controle (GIV. No 30º, 50º, 60º, 75º, 105º e 180º dias pós-infecção três camundongos dos grupos GI, GII e GIII e dois do

  11. Experimental Infections Of Domestic Rabbits ( Oryctolagus cuniculus ...

    African Journals Online (AJOL)

    Nigerian Journal of Animal Production ... Comparative study of single infections of domestic rabbits (Oryctolagus cuniculus) with Nigerian isolates of Trypanosoma brucei (Gboko strain), and Trypanosoma congolense (Binchi ... Eighteen rabbits of 10-14 weeks old weighing between 600-1200 grams were used for the study.

  12. Experimental Infection of Sheep using Infective Lar- vae (L3 ...

    African Journals Online (AJOL)

    Vet. J., 2014, 18 (2), 71-81 ther research is recommended to determine the impact of multiple-species habitat ... to be reservoir hosts of helminth infections than wild species (Cook et al., 1979;. Richardson and Demarias .... coincidentally there was also a positive relationship, Regression statistics. (R²=0.6696) between total ...

  13. Parasitological and molecular diagnosis in experimental Strongyloides venezuelensis infection.

    Science.gov (United States)

    Paula, Fabiana Martins; Sitta, Renata Barnabé; Malta, Fernanda Mello; Gottardi, Maiara; Corral, Marcelo Andreetta; Gryschek, Ronaldo César Borges; Chieffi, Pedro Paulo

    2013-01-01

    Strongyloides venezuelensis is a parasitic nematode of rats which is frequently used as a model to study human and animal strongyloidiasis. The aim of this study was to evaluate the correlation between parasitological and molecular diagnosis in Strongyloides venezuelensis infection. PCR assays were used to detect S. venezuelensis DNA in fecal samples obtained from experimentally infected Rattus norvegicus. The results showed a higher sensitivity of the PCR assay in detecting the infection compared to parasitological methods.

  14. Infections in orthopaedic surgery : clinical and experimental studies

    NARCIS (Netherlands)

    Vogely, Henri Charles

    2000-01-01

    The diagnostic difficulties, variability in outcome and the heterogeinity of the problem of orthopaedic infections stimulated the author to a study of the literature, and several clinical and experimental studies. The diagnosis prosthesis-related infection can only be reached with an acceptable

  15. Changes in microbiota during experimental human Rhinovirus infection

    NARCIS (Netherlands)

    Hofstra, J. J.; Matamoros, S.; van de Pol, M. A.; de Wever, B.; Tanck, M. W.; Wendt-Knol, H.; Deijs, M.; van der Hoek, L.; Wolthers, K. C.; Molenkamp, R.; Visser, C. E.; Sterk, P. J.; Lutter, R.; de Jong, M. D.

    2015-01-01

    Human Rhinovirus (HRV) is responsible for the majority of common colds and is frequently accompanied by secondary bacterial infections through poorly understood mechanisms. We investigated the effects of experimental human HRV serotype 16 infection on the upper respiratory tract microbiota. Six

  16. Experimental test of host specificity in a behaviour-modifying trematode

    DEFF Research Database (Denmark)

    Hernandez, R.N.; Fredensborg, Brian Lund

    2015-01-01

    Host behavioural modification by parasites is a common and well-documented phenomenon. However, knowledge on the complexity and specificity of the underlying mechanisms is limited, and host specificity among manipulating parasites has rarely been experimentally verified. We tested the hypothesis...... that the ability to infect and manipulate host behaviour is restricted to phylogenetically closely related hosts. Our model system consisted of the brain-encysting trematode Euhaplorchis sp. A and six potential fish intermediate hosts from the Order Cyprinodontiformes. Five co-occurring cyprinids were examined...... for naturally acquired brain infections. Then we selected three species representing three levels of taxonomic relatedness to a known host to experimentally evaluate their susceptibility to infection, and the effect of infection status on behaviours presumably linked to increased trophic transmission. We found...

  17. Species-specific nested PCR as a diagnostic tool for Brucella ovis infection in rams

    Directory of Open Access Journals (Sweden)

    L.F. Costa

    2013-02-01

    Full Text Available The aim of the present study was to evaluate a species-specific nested PCR based on a previously described species-specific PCR for detection of B. ovis in semen and urine samples of experimentally infected rams. The performance of the species-specific nested PCR was compared with the results of a genus-specific PCR. Fourteen rams were experimentally infected with the Brucella ovis REO 198 strain and samples of semen and urine were collected every week up to 180 days post infection. Out of 83 semen samples collected, 42 (50.6% were positive for the species-specific nested PCR, and 23 (27.7% were positive for the genus-specific PCR. Out of 75 urine samples, 49 (65.3% were positive for the species-specific nested PCR, whereas 11 (14.6% were genus-specific PCR positive. Species-specific nested PCR was significantly more sensitive (P<0.001 than the genus-specific PCR in semen and urine from experimentally infected rams. In conclusion, the species-specific nested PCR developed in this study may be used as a diagnostic tool for the detection of B. ovis in semen and urine samples from suspected rams.

  18. Protective effects of pidotimod against experimental bacterial infections in mice.

    Science.gov (United States)

    Coppi, G; Falcone, A; Manzardo, S

    1994-12-01

    Pidotimod ((R)-3-[(S)-(5-oxo-2-pyrrolidinyl) carbonyl]-thiazolidine-4-carboxylic acid, PGT/1A, CAS 121808-62-6) protected mice against experimental bacterial infections in different experimental models. In all tests the drug's effect was measured as protection from death. The activity of pidotimod was evident and statistically significant after 5 administrations before the bacterial challenges. Pidotimod was active against many bacterial species infections, its active dosages ranging from 0.01 to 100 mg/kg i.p. x 5 times. Pidotimod showed against some bacterial infections a protection similar or better than those of bestatin, N-acetylmuramyl-L-Ala-D-isoGlu-OH and tuftsin. It showed high protection against bacterial infections in cyclophosphamide-immunodepressed mice. Finally, pidotimod showed an additive or synergic activity in combination with beta-lactam antibiotics (cefotaxime, ampicillin) against bacterial infections in mice.

  19. Experimental rhinovirus infection in COPD: implications for antiviral therapies.

    Science.gov (United States)

    Gunawardana, Natasha; Finney, Lydia; Johnston, Sebastian L; Mallia, Patrick

    2014-02-01

    Chronic obstructive pulmonary disease (COPD) is a major public health problem and will be one of the leading global causes of mortality over the coming decades. Much of the morbidity, mortality and health care costs of COPD are attributable to acute exacerbations, the commonest causes of which are respiratory infections. Respiratory viruses are frequently detected in COPD exacerbations but direct proof of a causative relationship has been lacking. We have developed a model of COPD exacerbation using experimental rhinovirus infection in COPD patients and this has established a causative relationship between virus infection and exacerbations. In addition it has determined some of the molecular mechanisms linking virus infections to COPD exacerbations and identified potential new therapeutic targets. This new data should stimulate research into the role of antiviral agents as potential treatments for COPD exacerbations. Testing of antiviral agents has been hampered by the lack of a small animal model for rhinovirus infection and experimental rhinovirus infection in healthy volunteers has been used to test treatments for the common cold. Experimental rhinovirus infection in COPD subjects offers the prospect of a model that can be used to evaluate the effects of new treatments for virus-induced COPD exacerbations, and provide essential data that can be used in making decisions regarding large scale clinical trials. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Recrudescent Campylobacter jejuni infection in an immunocompetent adult following experimental infection with a well-characterized organism.

    Science.gov (United States)

    Baqar, Shahida; Tribble, David R; Carmolli, Marya; Sadigh, Katrin; Poly, Frederic; Porter, Chad; Larsson, Catherine J; Pierce, Kristen K; Guerry, Patricia; Darsley, Michael; Kirkpatrick, Beth

    2010-01-01

    The recrudescence of infection with Campylobacter jejuni after appropriate antibiotic treatment has not been previously reported in an immunocompetent adult. We present the complete clinical, microbiologic, and immunologic evaluation of a closely monitored healthy male with recrudescent C. jejuni infection occurring in the absence of immunodeficiency following experimental infection with a well-characterized strain. After antibiotic treatment, the initial infection was clinically cleared and microbiologically undetectable. Subsequently, two episodes of recrudescence occurred, with no change in in vitro antibiotic sensitivity being detected. The immune responses of the individual were compared to those of other participants in the experimental infection study: innate immune responses, including fecal cytokines and C-reactive protein, were intact; however, measures of Campylobacter-specific adaptive immune responses were absent, including serum antibodies, antibody-secreting cells, and in vitro gamma interferon responses. No primary or secondary immunodeficiency was identified. Recrudescent Campylobacter infections after treatment may be more common than has previously been appreciated. This work adds to our understanding of the human immune response to natural Campylobacter infection and reiterates the importance of pathogen-specific adaptive immune responses to this globally important pathogen.

  1. Recrudescent Campylobacter jejuni Infection in an Immunocompetent Adult following Experimental Infection with a Well-Characterized Organism▿ †

    Science.gov (United States)

    Baqar, Shahida; Tribble, David R.; Carmolli, Marya; Sadigh, Katrin; Poly, Frederic; Porter, Chad; Larsson, Catherine J.; Pierce, Kristen K.; Guerry, Patricia; Darsley, Michael; Kirkpatrick, Beth

    2010-01-01

    The recrudescence of infection with Campylobacter jejuni after appropriate antibiotic treatment has not been previously reported in an immunocompetent adult. We present the complete clinical, microbiologic, and immunologic evaluation of a closely monitored healthy male with recrudescent C. jejuni infection occurring in the absence of immunodeficiency following experimental infection with a well-characterized strain. After antibiotic treatment, the initial infection was clinically cleared and microbiologically undetectable. Subsequently, two episodes of recrudescence occurred, with no change in in vitro antibiotic sensitivity being detected. The immune responses of the individual were compared to those of other participants in the experimental infection study: innate immune responses, including fecal cytokines and C-reactive protein, were intact; however, measures of Campylobacter-specific adaptive immune responses were absent, including serum antibodies, antibody-secreting cells, and in vitro gamma interferon responses. No primary or secondary immunodeficiency was identified. Recrudescent Campylobacter infections after treatment may be more common than has previously been appreciated. This work adds to our understanding of the human immune response to natural Campylobacter infection and reiterates the importance of pathogen-specific adaptive immune responses to this globally important pathogen. PMID:19923572

  2. Experimental Infections of Wild Birds with West Nile Virus

    Directory of Open Access Journals (Sweden)

    Elisa Pérez-Ramírez

    2014-02-01

    Full Text Available Avian models of West Nile virus (WNV disease have become pivotal in the study of infection pathogenesis and transmission, despite the intrinsic constraints that represents this type of experimental research that needs to be conducted in biosecurity level 3 (BSL3 facilities. This review summarizes the main achievements of WNV experimental research carried out in wild birds, highlighting advantages and limitations of this model. Viral and host factors that determine the infection outcome are analyzed in detail, as well as recent discoveries about avian immunity, viral transmission, and persistence achieved through experimental research. Studies of laboratory infections in the natural host will help to understand variations in susceptibility and reservoir competence among bird species, as well as in the epidemiological patterns found in different affected areas.

  3. Experimental Infections of Wild Birds with West Nile Virus

    Science.gov (United States)

    Pérez-Ramírez, Elisa; Llorente, Francisco; Jiménez-Clavero, Miguel Ángel

    2014-01-01

    Avian models of West Nile virus (WNV) disease have become pivotal in the study of infection pathogenesis and transmission, despite the intrinsic constraints that represents this type of experimental research that needs to be conducted in biosecurity level 3 (BSL3) facilities. This review summarizes the main achievements of WNV experimental research carried out in wild birds, highlighting advantages and limitations of this model. Viral and host factors that determine the infection outcome are analyzed in detail, as well as recent discoveries about avian immunity, viral transmission, and persistence achieved through experimental research. Studies of laboratory infections in the natural host will help to understand variations in susceptibility and reservoir competence among bird species, as well as in the epidemiological patterns found in different affected areas. PMID:24531334

  4. Infectivity of Trichinella papuae for experimentally infected red foxes (Vulpes vulpes)

    DEFF Research Database (Denmark)

    Webster, P.; Malakauskas, A.; Kapel, C. M O

    2002-01-01

    To evaluate infectivity for carnivores as well as other biological characteristics of the newly described Trichinella papuae, eight red foxes were experimentally infected with the parasite. Five weeks after inoculation, T. papuae larvae were recovered from nine different muscle types. The larvae...

  5. Performance of commercially available serological diagnostic tests to detect Leishmania infantum infection on experimentally infected dogs.

    Science.gov (United States)

    Rodríguez-Cortés, Alhelí; Ojeda, Ana; Todolí, Felicitat; Alberola, Jordi

    2013-01-31

    Leishmania infantum (syn. Leishmania chagasi) is the etiological agent of a widespread serious zoonotic disease that affects both humans and dogs. Prevalence and incidence of the canine infection are important parameters to determine the risk and the ways to control this reemergent zoonosis. Unfortunately, there is not a gold standard test for Leishmania infection. Our aim was to assess the operative validity of commercial tests used to detect antibodies to Leishmania in serum samples from experimental infections. Three ELISA tests (LEISCAN(®) Leishmania ELISA Test, INGEZIM(®) LEISHMANIA, and INGEZIM(®) LEISHMANIA VET), three immunochromatographic tests (INGEZIM(®) LEISHMACROM, SNAP(®) Leishmania, and WITNESS(®) Leishmania), and one IFAT were evaluated. LEISCAN(®) Leishmania ELISA test achieved the highest sensitivity and accuracy (both 0.98). Specificity was 1 for all tests except for IFAT. All tests but IFAT obtained a positive predictive value of 1, while the maximum negative predictive value was achieved by LEISCAN(®) Leishmania ELISA Test (0.93). The best positive likelihood ratio was obtained by INGEZIM(®) LEISHMANIA VET (30.26), while the best negative likelihood ratio was obtained by LEISCAN(®) Leishmania ELISA Test (0.02). The highest diagnostic odds ratio was achieved by LEISCAN(®) Leishmania ELISA Test (729.00). The largest area under the ROC curve was obtained by LEISCAN(®) Leishmania ELISA Test (0.981). Quantitative ELISA based tests performmed better than qualitative tests ("Rapid Tests"), and the test best suited to detect Leishmania in infected dogs and to provide clinically useful information was LEISCAN(®) Leishmania ELISA Test. This and other results point also to the need of revising the status of IFAT as a gold standard for the diagnosis of leishmaniasis. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Experimental Theileria lestoquardi infection in sheep: Biochemical and hematological changes.

    Science.gov (United States)

    Yaghfoori, Saeed; Mohri, Mehrdad; Razmi, Gholamreza

    2017-09-01

    Malignant theileriosis (Theileria lestoquardi infection) is a hemoparasitic tick-borne disease that affects both wild and domestic small ruminants. The aim of this study was to evaluate biochemical and hematological characteristics of sheep after being experimentally infected by T. lestoquardi. T. lestoquardi infection was induced in seven Baluchi sheep of six-to-eight months old via experimentally-infected Hyalomma anatolicum adult ticks. Biochemical and hematological parameters were measured twice a week during the three weeks' post infection. Twenty-three biochemical analytes and seven hematological ones were measured. After three to four days infection, body temperature rose above 40(°)C. Maximum and minimum parasitaemia were 3.3% and 0.28%, respectively. Piroplasms and schizont were seen on average from days 7.2 and 4 post infection, respectively. The concentrations and activities of Alb, HDL, ALT, T3, T4, Ca, Fe, Mg, iP, WBC, RBC, PCV, Hb, Plt, neutrophil and lymphocytes significantly decreased (P≤0.05) during experimental infection. However, concentrations and activities of BT, GGT, Glu, BUN, Crea, FIB and Cu significantly increased (P≤0.05). There was no significant change in the serum amounts of Chol, LDL, TG, VLDL and Zn. The observed hypoalbuminemia and increase of FIB concentrations referred to pro-inflammatory cytokines production. Moreover, the raising of GGT activity indicates liver damage, cholestatic disorders or schizont infiltration. The disease stress and corticosteroids are suspected to cause the Glu concentration increase. The present study is aimed at improving the knowledge of malignant theileriosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Immunobiological characterization of Graphidium strigosum experimental infection in rabbits (Oryctolagus cuniculus).

    Science.gov (United States)

    Cuquerella, M; Alunda, J M

    2009-01-01

    An experimental infection of rabbits with a wild isolate of the gastric nematode Graphidium strigosum was carried out. Animals (3.5 months age) were infected with 1,000 L3 administered by bucoesophagic catheter (five rabbits) or kept as uninfected control group (five animals). The infection was maintained for 3 months. Along the experimental period, some parasitological, hematological and immunological parameters were determined. Prepatent period of the infection ranged from 30 to 38 days and, at necropsy, average adult helminth counts were 430.75 +/- 126.12. No significant variations were found in packed cell volume, leukocyte, and eosinophil counts along the experimental period. Infection elicited a clear serum-specific IgG response, estimated by ELISA, during patency. Pooled sera from the patent period of the infection recognized some soluble antigens, particularly, a 67-kDa protein. Experimentally infected animals did not show cross recognition between G. strigosum, Haemonchus contortus, and Teladorsagia circumcincta. However, Western blot analysis with hyperimmune sera against H. contortus raised in rabbits and lambs showed cross reactivity between this helminth species and G. strigosum.

  8. Nocardia brasiliensis: from microbe to human and experimental infections.

    Science.gov (United States)

    Salinas-Carmona, M C

    2000-09-01

    Nocardia brasiliensis is a Gram-positive bacterium that lives as a saprophyte in soil. In this article the physical properties, chemical composition and taxonomic position of this species is reviewed. Human infections and an experimental model of actinomycetoma in BALB/c mice as well as the host-immune response is described.

  9. Cardiac complication after experimental human malaria infection: a case report

    Directory of Open Access Journals (Sweden)

    Druilhe Pierre

    2009-12-01

    Full Text Available Abstract A 20 year-old healthy female volunteer participated in a clinical Phase I and IIa safety and efficacy trial with candidate malaria vaccine PfLSA-3-rec adjuvanted with aluminium hydroxide. Eleven weeks after the third and last immunization she was experimentally infected by bites of Plasmodium falciparum-infected mosquitoes. When the thick blood smear became positive, at day 11, she was treated with artemether/lumefantrine according to protocol. On day 16 post-infection i.e. two days after completion of treatment, she woke up with retrosternal chest pain. She was diagnosed as acute coronary syndrome and treated accordingly. She recovered quickly and her follow-up was uneventful. Whether the event was related to the study procedures such as the preceding vaccinations, malaria infection or antimalarial drugs remains elusive. However, the relation in time with the experimental malaria infection and apparent absence of an underlying condition makes the infection the most probable trigger. This is in striking contrast, however, with the millions of malaria cases each year and the fact that such complication has never been reported in the literature. The rare occurrence of cardiac events with any of the preceding study procedures may even support a coincidental finding. Apart from acute coronary syndrome, myocarditis can be considered as a final diagnosis, but the true nature and patho-physiological explanation of the event remain unclear.

  10. Analysis of experimental mink enteritis virus infection in mink: in situ hybridization, serology, and histopathology

    DEFF Research Database (Denmark)

    Uttenthal, Åse; Larsen, S; Lund, E

    1990-01-01

    Strand-specific hybridization probes were used in in situ hybridization studies to localize cells containing mink enteritis virus (MEV) virion DNA or MEV replicative-form DNA and mRNA. Following the experimental MEV infection of 3-month-old unvaccinated mink, a significant increase in serum antib...

  11. Avian toxoplasmosis: experimental infection of chicken and pigeon.

    Science.gov (United States)

    Biancifiori, F; Rondini, C; Grelloni, V; Frescura, T

    1986-01-01

    Two groups of 13 new-laying hens each were infected by crop-route with 5000 and 50,000 infective oocysts of T. gondii. Four groups of 5 pigeons each were inoculated by crop-route with 50, 500, 1000 and 5000 infective oocysts. To each group of infected birds suitable controls were added. Hens from the experiment with 5000 infective oocysts were apparently resistant to the infection and they had no clinical signs in the succeeding 40 days p.i. Hens from the experiment with 50,000 infective oocysts showed an egg-drop and mortality in embryonated eggs, especially during the first 2 weeks p.i. Isolation of the parasite was unsuccessfully attempted from 720 embryonated eggs, produced by infected groups, and tested on various days p.i. and at different stages of infection. The parasite was isolated from the brain, heart, liver, spleen and lung of infected birds 7 and 15 days p.i.; 40 days p.i. it was evident only in brain and heart. IgG onset and mean course were monitored by ELISA and high titers were reached by both groups. Pigeons from groups 500, 1000 and 5000 developed rapidly progressive clinical signs as diarrhea, trembling, incoordination, torticollis and death. They had enlargement of liver and spleen and focal necrosis, nodular features in the crop. Pigeons from expt 50 had no clinical signs in spite of the presence of the parasite in their organs for over 45 days p.i. Parasite was isolated from brain, heart, liver, spleen, lung, kidney, crop and muscles from all infected groups. Histopathological and ultrastructural features revealed the presence of multiplying tachizoites even within cells of the crop. Seroconversion, as monitored by ELISA, was recorded in all infected groups although high ELISA-titres were never reached. One of the negative controls from expt 5000 developed specific antibodies but the parasite was not isolated from its organs.

  12. Sterilizing immunity to influenza virus infection requires local antigen-specific T cell response in the lungs

    OpenAIRE

    Avijit Dutta; Ching-Tai Huang; Chun-Yen Lin; Tse-Ching Chen; Yung-Chang Lin; Chia-Shiang Chang; Yueh-Chia He

    2016-01-01

    Sterilizing immunity is a unique immune status, which prevents effective virus infection into the host. It is different from the immunity that allows infection but with subsequent successful eradication of the virus. Pre-infection induces sterilizing immunity to homologous influenza virus challenge in ferret. In our antigen-specific experimental system, mice pre-infected with PR8 influenza virus through nasal route are likewise resistant to reinfection of the same strain of virus. The virus i...

  13. Ocular pathological changes in hamsters experimentally infected with Schistosoma mansoni.

    Science.gov (United States)

    Ismail, H I H; Ashour, D S; Abou Rayia, D M; Ali, A L

    2016-11-01

    Ocular lesions have been reported in patients with schistosomiasis; however, the problem with studying schistosomal infection of the human eye is that biopsies are almost impossible to take, and histopathological examination of suspicious lesions can only be undertaken post-mortem or after enucleation. This work aimed to study the possible effects and pathogenesis of schistosomiasis on the eye. This study involved 55 hamsters; five hamsters remained non-infected and the remaining 50 hamsters were infected with Schistosoma mansoni cercariae. Infected hamsters were sacrificed on weeks 8, 12, 16 and 20 post-infection (pi). Eye sections were prepared and stained for histopathological and immunohistochemical studies. Histopathological changes detected in hamsters infected after 16 and 20 weeks included looseness and oedema of the innermost retinal layers together with hyperplastic polypoid growth. Neither eggs nor granulomata were detected in eye sections throughout the experimental period. Deposition of S. mansoni antigen was revealed in 35% of infected hamsters. Later, on weeks 16 and 20 pi, moderate subepithelial conjuctival deposits and marked subchoroidal and scleral deposition were detected. In conclusion, the deposition of schistosomal antigen and immune complexes may play a pivotal role in the ocular changes that occur in schistosomiasis, even in the absence of detectable Schistosoma eggs. Schistosomiasis should be suspected in cases with unexplained ophthalmological findings, especially in endemic areas.

  14. The role of IL-12 in experimental Trypanosoma cruzi infection

    Directory of Open Access Journals (Sweden)

    J.S. Silva

    1998-01-01

    Full Text Available Host resistance to Trypanosoma cruzi infection is dependent on both natural and acquired immune responses. During the early acute phase of infection in mice, natural killer (NK cell-derived IFN-g is involved in controlling intracellular parasite replication, mainly through the induction of nitric oxide biosynthesis by activated macrophages. We have shown that IL-12, a powerful inducer of IFN-g production by NK cells, is synthesized soon after trypomastigote-macrophage interaction. The role of IL-12 in the control of T. cruzi infection in vivo was determined by treating infected mice with anti-IL-12 monoclonal antibody (mAb and analyzing both parasitemia and mortality during the acute phase of infection. The anti-IL-12 mAb-treated mice had higher levels of parasitemia and mortality compared to control mice. Also, treatment of infected mice with mAb specific for IFN-g or TNF-a inhibited the protective effect of exogenous IL-12. On the other hand, TGF-ß and IL-10 produced by infected macrophages inhibited the induction and effects of IL-12. Therefore, while IL-12, TNF-a and IFN-g correlate with resistance to T. cruzi infection, TGF-ß and IL-10 promote susceptibility. These results provide support for a role of innate immunity in the control of T. cruzi infection. In addition to its protective role, IL-12 may also be involved in the modulation of T. cruzi-induced myocarditis, since treatment of infected mice with IL-12 or anti-IL-12 mAb leads to an enhanced or decreased inflammatory infiltrate in the heart, respectively. Understanding the role of the cytokines produced during the acute phase of T. cruzi infection and their involvement in protection and pathogenesis would be essential to devise new vaccines or therapies.

  15. Pathogenicity of avian malaria in experimentally-infected Hawaii Amakihi

    Science.gov (United States)

    Atkinson, Carter T.; Dusek, Robert J.; Woods, K.L.; Iko, W.M.

    2000-01-01

    The introduction of avian malaria (Plasmodium relictum) and mosquitoes (Culex quinquefasciatus) to the Hawaiian Islands (USA) is believed to have played a major role in the decline and extinction of native Hawaiian honeycreepers (Drepanidinae). This introduced disease is thought to be one of the primary factors limiting recovery of honeycreepers at elevations below 1,200 m where native forest habitats are still relatively intact. One of the few remaining species of honeycreepers with a wide elevational distribution is the Hawaii Amakihi (Hernignathus virens). We measured morbidity and mortality in experimentally-infected Hawaii Amakihi that were captured in a high elevation, xeric habitat that is above the current range of the mosquito vector. Mortality among amakihi exposed to a single infective mosquito bite was 65% (13/20). All infected birds had significant declines in food consumption and a corresponding loss in body weight over the 60 day course of the experiment. Gross and microscopic lesions in birds that succumbed to malaria included enlargement and discoloration of the spleen and liver and parasitemias as high as 50% of circulating erythrocytes. Mortality in experimentally-infected amakihi was similar to that observed in Apapane (Himnatione sanguinea) and lower than that observed in Iiwi (Vestiaria coccinea) infected under similar conditions with the same parasite isolate. We conclude that the current elevational and geographic distribution of Hawaiian honeycreepers is determined by relative susceptibility to avian malaria.

  16. Experimental fetal and transplacental Neospora infection in the nonhuman primate.

    Science.gov (United States)

    Barr, B C; Conrad, P A; Sverlow, K W; Tarantal, A F; Hendrickx, A G

    1994-08-01

    Neospora is a newly recognized Toxoplasma-like protozoan that causes spontaneous abortion and/or neonatal disease in a wide range of animals. The purpose of this study was to determine the susceptibility of primates to Neospora infection. In experiment 1, two rhesus macaque fetuses were inoculated in utero at gestational day 65 with 1 x 10(6) culture-derived Neospora tachyzoites. A control fetus was given uninfected vehicle. The fetuses were removed by hysterotomy between 13 and 22 days postinoculation. In experiment 2, two pregnant macaques were inoculated intramuscularly and intravenously on gestational day 43 with a total of 1.6 x 10(7) culture-derived tachyzoites. A pregnant control macaque was given uninfected vehicle. The fetuses were removed by hysterotomy between 67 to 70 days postinoculation. Fetal tissues were collected for in vitro parasite isolation, histopathology, and Neospora immunohistochemistry. Fetal blood was examined for Neospora-specific antibody titers using an indirect fluorescent antibody test. Neospora infections were confirmed in all fetuses that received tachyzoites either directly or via transplacental infection. In experiment 1, infected fetuses had reduced amniotic fluid volumes, marked protozoal amnionitis and dermatitis, and a mild multifocal encephalitis. Infected fetuses from experiment 2 had a chronic multifocal necrotizing nonsuppurative meningoencephalitis with microcavitation, that was confined to the cerebrum, and a mild multifocal necrotizing amnionitis. In both experiments, Neospora tachyzoites were detected in association with lesions in fetal tissues by immunohistochemistry, and the parasites were reisolated in vitro. IgG Neospora antibody titers were detected in blood from all infected fetuses, whereas Neospora-specific IgM and IgA titers were found in one and three fetuses, respectively. Results indicate that nonhuman primates are susceptible to transplacental Neospora infection. The fetal lesions after transplacental

  17. Experimental model for Porphyromonas gingivalis infection in animals.

    Science.gov (United States)

    Eke, P I; Rotimi, V O; Laughon, B E

    1996-03-01

    A virulence model suitable for studying the dynamics of Porphyromonas gingivalis infection, including the pathogenicity of P. gingivalis in experimentally induced infections of multiple organs was developed using mouse and hamster. Virulence of P. gingivalis strains was expressed contrastingly in subcutaneous (sc) infection in the Murine abscess model (MAM) and the Hamsters abscess model (HAM). Subcutaneous infection in the MAM was characterized by a gravity abscess, spreading from the primary site of inoculation downwards, frequently erupting as a secondary lesion. In contract, s.c. P. gingivalis infection in HAM was characterized as a palpable localized abscess at the primary site of inoculation. When the Semi-Solid Agar (SSA) was added to the mono-culture of P. gingivalis, reproducibility of infection in both models was enhanced. P. gingivalis culture supplemented with haemin, or combined with oral Actinomyces viscosus had its virulence overtly enhanced and often fatal in the MAM. Menadione, Eh reducing agents and mixture with the Streptococcus or A. neaslundii did not potentiate virulence in either mode. Transtracheal challenge of the lungs of hamster with P. gingivalis initiated an early pneumonitis and later sequelae of necrosis and abscess formation. Also, abscess was induced by direct inoculation of P. gingivalis in the muscles, liver and testes, but did not induce intra-abdominal abscesses. In conclusion, the HAM applied with the SSA procedure caused a localized P. gingivalis tissue infection with practical advantages for quantitative and qualitative studies of P. gingivalis infections. This study also demonstrates the pathogenic potential of P. gingivalis by reproducing similar infections in multiple anatomical sites.

  18. Persistence of viral RNA in the brain of experimentally infected mice with coxsackievirus B5

    Directory of Open Access Journals (Sweden)

    Sobotova Z.

    2011-04-01

    Full Text Available The aim of our study was to follow the persistence of viral RNA in selected organs of experimentally infected with coxsackievirus (CV B5 strains from different sources such as a patient’s sample, an environmental sample and a prototype virus strain. Methods . CD-1 mice were infected with CVB5 strain Faulkner the prototype, CVB5 – isolate from treated sewage waste and isolate from patient’s stool sample both identified as CVB5. The viral RNA was detected by RT-PCR using enterovirus primers specific for the non-coding 5' region. Results . We observed presence of RNA in the brain and heart of mice infected with isolate from patient’s stool at day 45 post infection (p. i.. Conclusion. We conclude that CVB5 persists in the brain and heart after oral infection of CD1 mice. The relevance of viral persistence maybe related viral origin and the genetics

  19. Experimental Babesia gibsoni infection in coyotes (Canis latrans).

    Science.gov (United States)

    Evers, Holly V; Kocan, A Alan; Reichard, Mason V; Meinkoth, James H

    2003-10-01

    Four 5 mo old captive raised coyotes (Canis latrans) were experimentally inoculated with approximately 1 x 10(6) Babesia gibsoni organisms. Parasites were detected 1 wk post-inoculation in all coyotes with maximum parasitemia of 8-11% occurring at 34 wk. Parasitemias remained at or above 1% for at least 12 wk and were still detectable 20 wk post-inoculation. All experimentally infected coyotes developed pale mucous membranes, splenomegaly, and a positive heme reaction in urine while one coyote exhibited mild depression and inappetence. Infected coyotes also developed a regenerative anemia, thrombocytopenia, and neutropenia. The mild clinical signs coupled with the high level and long duration of parasitemia indicate that coyotes could serve as reservoirs for B. gibsoni. Entrance of this foreign parasite into the United States suggests the need for strict quarantines and thorough health and blood film examinations for imported animals.

  20. Protein Spesifik Cairan Kista Cysticercus bovis pada Sapi Bali yang Diinfeksi dengan Taenia saginata (SPECIFIC PROTEIN OF CYSTICERCUS BOVIS CYST FLUID ON BALI CATTLE EXPERIMENTALLY INFECTED WITH TAENIA SAGINATA

    Directory of Open Access Journals (Sweden)

    Nyoman Sadra Dharmawan

    2013-08-01

    Full Text Available Cysticercus bovis is the larval stage of Taenia saginata, the bovine tapeworm. The infection of thislarval in cattle musculature causes Bovine cysticercosis or Cysticercosis bovis.  Bovine cysticercosis is foundworldwide, but mostly in developing countries, where unhygienic conditions, poor cattle managementpractices, and the absence of meat inspection are common.  The adult Taenia infection in man is referredto as taeniasis.  Taenia saginata taeniasis is also found almost all over the world.  The prevalence ofTaenia saginata taeniasis has reported up to 27.5% in Gianyar Bali. In order to control the diseases,vaccination against the larvae stages in cattle of Taenia saginata may play an important role in controllingthe disease in the endemic regions.  The aims of the present study were to prepare and to investigate theimmunogenic protein as vaccine candidate for controlling  Cysticercus bovis infection in in Bali cattle.Cysticercus protein from the cyst fluid was firstly used to immunize mice and the mice sera were thencollected. Cysticercus proteins then analyzed using sodium dodecyl sulfate-gel electrophoresis (SDS-PAGE.All cysticercus proteins were then visualized by Commasie blue staining. The proteins were also transferredonto nitrocellulose membrane and the immunogenic proteins were visualized by Western Blotting usingimmune sera raised in mice.  By Commasie blue staining, a total of 17 proteins were detected with themolecular weight of 14,86 kDa -122,40 kDa from the smallest to the largest. As many as 7 immunogenicproteins with the molecular weights of 16.81 kDa; 19.22 kDa; 20.98 kDa; 27.41 kDa; 34.02 kDa; 38.31 kDa;and 54.94kDa were detected.

  1. Gastritis induced by Helicobacter pylori infection in experimental rats.

    Science.gov (United States)

    Elseweidy, Mohamed M; Taha, Mona M; Younis, Nahla N; Ibrahim, Khadiga S; Hamouda, Hamdi A; Eldosouky, Mohamed A; Soliman, Hala

    2010-10-01

    Gastritis, an inflammation of gastric mucosa, may be due to many pathological factors and infection, such as with Helicobacter pylori. The use of experimental models of gastritis is important to evaluate the biochemical changes and study chemotherapeutic intervention. In a previous study we demonstrated an acute gastritis model induced by iodoacetamide. Our objective in this study was to evaluate a new gastritis model induced by H. pylori infection in experimental rats in terms of certain biomarkers in serum and mucosal tissues in addition to histopathological examination. Gastritis was induced in 20 albino Wistar rats by H. pylori isolated from antral biopsy taken from a 49-year-old male patient endoscopically diagnosed as having H. pylori infection. Another ten rats were used as controls. Serum gastrin, pepsinogen I activity, interleukin-6 (IL-6) and gastric mucosal myeloperoxidase (MPO) activity and prostaglandin E(2) (PGE(2)) were measured. Immunostaining for inducible nitric oxide synthase (iNOS), nitrotyrosine and DNA fragmentation were used to further evaluate H. pylori-induced gastritis. Serum gastrin, IL-6, mucosal MPO activity, and PGE(2) demonstrated significant increases joined with a decreased serum pepsinogen I activity (P gastritis models demonstrated massive oxidative stress and pronounced injury in mucosal tissue. Since our model in rats reflected the clinical picture of H. pylori infection, it can be considered as a consistent model to study chemotherapeutic intervention for this type of gastritis.

  2. Inferring biomarkers for Mycobacterium avium subsp. paratuberculosis infection and disease progression in cattle using experimental data

    Science.gov (United States)

    Magombedze, Gesham; Shiri, Tinevimbo; Eda, Shigetoshi; Stabel, Judy R.

    2017-03-01

    Available diagnostic assays for Mycobacterium avium subsp. paratuberculosis (MAP) have poor sensitivities and cannot detect early stages of infection, therefore, there is need to find new diagnostic markers for early infection detection and disease stages. We analyzed longitudinal IFN-γ, ELISA-antibody and fecal shedding experimental sensitivity scores for MAP infection detection and disease progression. We used both statistical methods and dynamic mathematical models to (i) evaluate the empirical assays (ii) infer and explain biological mechanisms that affect the time evolution of the biomarkers, and (iii) predict disease stages of 57 animals that were naturally infected with MAP. This analysis confirms that the fecal test is the best marker for disease progression and illustrates that Th1/Th2 (IFN-γ/ELISA antibodies) assays are important for infection detection, but cannot reliably predict persistent infections. Our results show that the theoretical simulated macrophage-based assay is a potential good diagnostic marker for MAP persistent infections and predictor of disease specific stages. We therefore recommend specifically designed experiments to test the use of a based assay in the diagnosis of MAP infections.

  3. SPECIFIC ANTIBODY DEFICIENCY IN CHILDREN SUFFERING RECURRENT INFECTIONS

    Directory of Open Access Journals (Sweden)

    M. Naseri. G.P. Spickett

    1999-08-01

    Full Text Available Specific antibody deficiency lias been recognized as an immunodeficiency. In order to investigate an antipolysaccliaride antibody defect as a cause of rcccttrent infections, 30 children were studied. Patients who had been identified to have a major immunodeficiency or structural abnormality or a disease known to cause infection were excluded."nTliirty patints, aged I to 13.8 years (mean age, 5.8; male; female, 13:17 were chosen; all liad normal IgG and IgGl. Tiic level of IgA, IgG2 and lgG3 were of lower than normal in some cases. All were immunized with Hih conjugate (PRI'-T vaccine, and 26 with pneumococcal vaccine. Antibody responses were measured 4-6 weeks later. Twelve showed a poor response to immunization: 8 to pneumovax 3 to Hib and 1 to both. No correlation was observed between IgG 2 level anil specific antibody responses to polysacciiaridc antigens. Tlie infections were more severe and more frequent in children who responded poorly to polysacciiaridc antigens. Chikircn who had infections in more than one site were most likely to have deficient antibody responses."nThese results show that assessment of specific antibody responses to challenge immunization is an essential part of the investigation of children suffering from recurrent pyogenic infections. The study confirms that measurement of immunoglobulin isotypes and IgG subclasses atone docs not exclude significant hormonal immune deficiency.

  4. Specific eradication of HIV-1 from infected cultured cells

    Directory of Open Access Journals (Sweden)

    Levin Aviad

    2010-08-01

    Full Text Available Abstract A correlation between increase in the integration of Human Immunodeficiency virus-1 (HIV-1 cDNA and cell death was previously established. Here we show that combination of peptides that stimulate integration together with the protease inhibitor Ro 31-8959 caused apoptotic cell death of HIV infected cells with total extermination of the virus. This combination did not have any effect on non-infected cells. Thus it appears that cell death is promoted only in the infected cells. It is our view that the results described in this work suggest a novel approach to specifically promote death of HIV-1 infected cells and thus may eventually be developed into a new and general anti-viral therapy.

  5. Dengue Virus-Specific Antibodies Enhance Brazilian Zika Virus Infection.

    Science.gov (United States)

    Castanha, Priscila M S; Nascimento, Eduardo J M; Braga, Cynthia; Cordeiro, Marli T; de Carvalho, Otávio V; de Mendonça, Leila R; Azevedo, Elisa A N; França, Rafael F O; Dhalia, Rafael; Marques, Ernesto T A

    2017-03-01

    Anti-Flavivirus antibodies are highly cross-reactive and may facilitate Zika virus (ZIKV) infection through the antibody-dependent enhancement (ADE) mechanism. We demonstrate that dengue-specific antibodies enhance the infection of a primary Brazilian ZIKV isolate in a FcγRII-expressing K562 cell line. In addition, we demonstrate that serum samples from dengue-immune pregnant women enhanced ZIKV infection. These findings highlight the need for epidemiological studies and animal models to further confirm the role of ADE in the development of congenital and neurological complications associated with ZIKV infections. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  6. Mono- and combined antimicrobial agents efficiency in experimental wound infection

    Directory of Open Access Journals (Sweden)

    Наталія Ігорівна Філімонова

    2015-10-01

    Full Text Available Modern problems of antibiotic therapy are shown by wide range of side effects, both on organism and microbiological levels: the spread of allergies, toxic for organ systems reactions, dysbiosis development, and resistant pathogens formation and dissemination. Therefore the necessity of search for new effective drugs with significant antimicrobial activity applied for the wounds treatment arises. Development of combined remedies on the background of different origin antimicrobial agents’ derivatives is one of the fight directions against infectious diseases in the skin pathology. Recently among the existing antimicrobial agents one should focus on antiseptic drugs, due to degenerative and dysfunctional effect on microbial cell.Aim of research. The comparison of mono- and combined antimicrobial agents chemotherapeutic efficiency in the treatment of localized purulent infection under experimental conditions.Metods. The study of chemotherapeutic efficiency was carried out on the model of localized purulent Staphylococcus infection on albino mice weighting 14 – 16 g. S.aureus ATCC 25923 strains were used as infectious agents. The contamination was performed subcutaneously to the right side of mice’s skin after depilation. The animals were randomly divided into 4 groups: the 1st group – infected mice without treatment (control; the 2nd group – infected mice treated with a ciprofloxacin; the 3rd group – infected mice treated with a Ciprofloxacin and Decamethoxin combination; the 4th group – infected mice treated with a combined drug on the base of mutual prodrugs (Hexamethylenetetramine and Phenyl salicylate.Results. The efficiency of mono- and combined antimicrobial agents under experimental Staphylococcus wound infection conditions was studied. It was found that localized purulent staph center was formed more slowly in comparison with control and mono preparation use (2nd group of animals. The average index of skin lesions in comparison

  7. Effects of Experimental Sarcocystis neurona-Induced Infection on Immunity in an Equine Model

    Directory of Open Access Journals (Sweden)

    S. Rochelle Lewis

    2014-01-01

    Full Text Available Sarcocystis neurona is the most common cause of Equine Protozoal Myeloencephalitis (EPM, affecting 0.5–1% horses in the United States during their lifetimes. The objective of this study was to evaluate the equine immune responses in an experimentally induced Sarcocystis neurona infection model. Neurologic parameters were recorded prior to and throughout the 70-day study by blinded investigators. Recombinant SnSAG1 ELISA for serum and CSF were used to confirm and track disease progression. All experimentally infected horses displayed neurologic signs after infection. Neutrophils, monocytes, and lymphocytes from infected horses displayed significantly delayed apoptosis at some time points. Cell proliferation was significantly increased in S. neurona-infected horses when stimulated nonspecifically with PMA/I but significantly decreased when stimulated with S. neurona compared to controls. Collectively, our results suggest that horses experimentally infected with S. neurona manifest impaired antigen specific response to S. neurona, which could be a function of altered antigen presentation, lack of antigen recognition, or both.

  8. Preferential infection sites of Cysticercus bovis in cattle experimentally infected with Taenia saginata eggs.

    Science.gov (United States)

    Lopes, Welber D Z; Santos, Thaís R; Soares, Vando E; Nunes, Jorge L N; Mendonça, Rafael P; de Lima, Roberto C A; Sakamoto, Cláudio A M; Costa, Gustavo H N; Thomaz-Soccol, Vanete; Oliveira, Gilson P; Costa, Alvimar J

    2011-02-01

    The preferential sites of infection of Cysticercus bovis were evaluated in the skeletal muscle and entrails of 25 cattle that were experimentally infected with Taenia saginata (2×10(4) eggs). Two other animals were not inoculated (control). Ninety days after inoculation, all the cattle were euthanized. The carcasses were deboned and dissected into 26 anatomical sections (masseter muscles, brain, tongue, esophagus, heart, diaphragm, lungs, liver, kidneys, spleen, top sirloin butt, bottom sirloin butt, outside round, top (inside) round, transversus abdominus, top sirloin cap, strip loin, full tenderloin, eye of round, knuckle, shoulder clod, foreshank, shank, chuck, back ribs, and tail muscles). The dissected tissues were sliced into 5mm sections. From the 25 cattle, 9258 C. bovis (cysticerci) were recovered; 75.02% (6946) of these were recovered from skeletal muscles and 24.98% (2312) from the entrails. A high parasitism level was found in the shoulder clod (12.55%), heart (11.02%), liver (9.48%), masseter muscles (8.51%), chuck (8.25%), strip loin and full tenderloin (7.26%), knuckle (6.63%), and back ribs (5.53%), totaling 69.23% (5738) of all of the detected cysticerci. On the other hand, there was a low C. bovis parasitism level in the brain, spleen, tail muscles, kidneys, esophagus, and diaphragm, representing just 3.9% of the total number of cysticerci. Given these results, we conclude that specific skeletal musculature regions, such as the shoulder blade, chuck, strip loin and full tenderloin, knuckle, back ribs and top round, which are not officially examined in many countries, are effective sites to efficiently screen C. bovis infection. To date, these regions have not been considered as preferential sites of C. bovis infection. Based on our work, however, these regions deserve greater attention from health inspectors because they contained a greater number of Cysticercus than the other regions of carcasses that are parasitized by T. saginata larvae

  9. Heterogeneous infectiousness in guinea pigs experimentally infected with Trypanosoma cruzi.

    Science.gov (United States)

    Castillo-Neyra, Ricardo; Borrini Mayorí, Katty; Salazar Sánchez, Renzo; Ancca Suarez, Jenny; Xie, Sherrie; Náquira Velarde, Cesar; Levy, Michael Z

    2016-02-01

    Guinea pigs are important reservoirs of Trypanosoma cruzi, the causative parasite of Chagas disease, and in the Southern Cone of South America, transmission is mediated mainly by the vector Triatoma infestans. Interestingly, colonies of Triatoma infestans captured from guinea pig corrals sporadically have infection prevalence rates above 80%. Such high values are not consistent with the relatively short 7-8 week parasitemic period that has been reported for guinea pigs in the literature. We experimentally measured the infectious periods of a group of T. cruzi-infected guinea pigs by performing xenodiagnosis and direct microscopy each week for one year. Another group of infected guinea pigs received only direct microscopy to control for the effect that inoculation by triatomine saliva may have on parasitemia in the host. We observed infectious periods longer than those previously reported in a number of guinea pigs from both the xenodiagnosis and control groups. While some guinea pigs were infectious for a short time, other "super-shedders" were parasitemic up to 22 weeks after infection, and/or positive by xenodiagnosis for a year after infection. This heterogeneity in infectiousness has strong implications for T. cruzi transmission dynamics and control, as super-shedder guinea pigs may play a disproportionate role in pathogen spread. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Detection of infectious laryngotracheitis virus by real-time PCR in naturally and experimentally infected chickens.

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    Full Text Available Infectious laryngotracheitis (ILT is an acute, highly contagious upper-respiratory infectious disease of chickens. In this study, a real-time PCR method was developed for fast and accurate detection and quantitation of ILTV DNA of chickens experimentally infected with ILTV strain LJS09 and naturally infected chickens. The detection lower limit of the assay was 10 copies of DNA. There were no cross reactions with the DNA and RNA of infectious bursal disease virus, chicken anemia virus, reticuloendotheliosis virus, avian reovirus, Newcastle disease virus, and Marek's disease virus. The real-time PCR was reproducible as the coefficients of variation of reproducibility of the intra-assay and the inter-assay were less than 2%. The real-time PCR was used to detect the levels of the ILTV DNA in the tissues of specific pathogen free (SPF chickens infected with ILTV at different times post infection. ILTV DNA was detected by real-time PCR in the heart, liver, spleen, lung, kidney, larynx, tongue, thymus, glandular stomach, duodenum, pancreatic gland, small intestine, large intestine, cecum, cecal tonsil, bursa of Fabricius, and brain of chickens in the infection group and the contact-exposure group. The sensitivity, specificity, and reproducibility of the ILTV real-time PCR assay revealed its suitability for detection and quantitation of ILTV in the samples from clinically and experimentally ILTV infected chickens.

  11. Age-specific prevalence of cervical human papillomavirus infection ...

    African Journals Online (AJOL)

    This cross-sectional study describes the age-specific prevalence of human papillomavirus (HPV) infection and cytological abnormalities among this urban and peri-urban population. Method. Over the period March 2009 - September 2011, 1 524 women attending public sector primary healthcare clinics were invited to

  12. SPECIFIC ANTIBODY DEFICIENCY IN CHILDREN SUFFERING RECURRENT INFECTIONS

    OpenAIRE

    M. Naseri. G.P. Spickett; AJ. Cant

    1999-01-01

    Specific antibody deficiency lias been recognized as an immunodeficiency. In order to investigate an antipolysaccliaride antibody defect as a cause of rcccttrent infections, 30 children were studied. Patients who had been identified to have a major immunodeficiency or structural abnormality or a disease known to cause infection were excluded."nTliirty patints, aged I to 13.8 years (mean age, 5.8; male; female, 13:17) were chosen; all liad normal IgG and IgGl. Tiic level of IgA, IgG2 and ...

  13. Early weight development of goats experimentally infected with Mycobacterium avium subsp. paratuberculosis.

    Directory of Open Access Journals (Sweden)

    Alyssa N Malone

    Full Text Available Johne's disease is an infectious chronic inflammatory bowel disease in ruminants. The key factor for the management of this disease is an early positive diagnosis. Unfortunately, most diagnostics detect animals with Johne's disease in the clinical stage with positive serology and/or positive fecal cultures. However, for effective management of the disease within herds, it is important to detect infected animals as early as possible. This might only be possible with the help of parameters not specific for Johne's disease but that give an early indication for chronic infections such as weight development. Here we report our findings on the development of total body weight and weight gain during the first six months of goats experimentally infected to induce Johne's disease. Twenty dairy goat kids age 2 to 5 days were included in this study. Goats were divided into two groups: a negative control group and a positive infected group. The weight was obtained weekly throughout the study. Goats of the positive group were infected at the age of seven weeks. We detected significant changes in weight gain and total body weight as early as one week after infection. Differences are significant throughout the six month time period. Weight as a non-specific parameter should be used to monitor infection especially in studies on Johne's disease using the goat model. Our study suggests that goats with Johne's disease have a reduced weight gain and reduced weight when compared with healthy goats of the same age.

  14. Effects of praziquantel on experimental Schistosoma bovis infection in goats.

    Science.gov (United States)

    Johansen, M V; Monrad, J; Christensen, N O

    1996-03-01

    The effect of praziquantel against experimental Schistosoma bovis infection in West African Dwarf goats was investigated. Thirty goats were exposed to 2000 cercariae each and 15 of those received a praziquantel treatment (60 mg kg-1) 13 weeks post-infection. One day, 1 week and 4 weeks post-treatment representative goats from each group were killed and worms were recovered by perfusion. For comparison, parasite-free control animals were monitored, some of which were given praziquantel. Every second week during the study, faecal samples were collected. The cure rate was 100% 1 day, 99.4% 1 week and 95.7% 4 weeks post-treatment. Tissue egg counts were significantly reduced (P < 0.001) 4 weeks post-treatment in all parts of the intestines, but not in the liver. Faecal egg counts were reduced by 84.1% 1 week and by 98.3% 3 weeks after treatment, the reduction being highly significant both 1 week 3 weeks after treatment (P < 0.001). Overall strong correlations between the number of worm pairs, tissue egg counts and the final faecal egg count were observed, indicating that the faecal egg counts during infection and following treatment can be used as a guideline for the pathology associated with the infection.

  15. Circulating levels of cyclooxygenase metabolites in experimental Trypanosoma cruzi infections

    Directory of Open Access Journals (Sweden)

    Rita L. Cardoni

    2004-01-01

    Full Text Available TRYPANOSOMA cruzi induces inflammatory reactions in several tissues. The production of prostaglandin F2α, 6-keto-prostaglandin F1α and thromboxane B2, known to regulate the immune response and to participate in inflammatory reactions, was studied in mice experimentally infected with T. cruzi. The generation of nitric oxide (NO, which could be regulated by cyclooxygenase metabolites, was also evaluated. In the acute infection the extension of inflammatory infiltrates in skeletal muscle as well as the circulating levels of cyclooxygenase metabolites and NO were higher in resistant C3H mice than in susceptible BALB/c mice. In addition, the spontaneous release of NO by spleen cells increased earlier in the C3H mouse strain. In the chronic infections, the tissue inflammatory reaction was still prominent in both groups of mice, but a moderate increase of thromboxane B2 concentration and in NO released by spleen cells was observed only in C3H mice. This comparative study shows that these mediators could be mainly related to protective mechanisms in the acute phase, but seem not to be involved in its maintenance in the chronic T. cruzi infections.

  16. Experimental rhinovirus infection in human volunteers exposed to ozone

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, F.W.; Dubovi, E.J.; Harder, S.; Seal, E. Jr.; Graham, D.

    1988-05-01

    We studied 24 young adult male volunteers experimentally inoculated with type 39 rhinovirus to determine whether the course of viral infection was modified by exposure to moderate levels of ozone (0.3 ppm for 6 h per day) over the 5 days after virus inoculation. No differences in rhinovirus titers in nasal secretions, recruitment of neutrophils into nasal secretions, levels of interferon in nasal lavage fluid, in vitro lymphocyte proliferative responses to rhinovirus antigen, or levels of convalescent serum neutralizing antibody to type 39 rhinovirus were demonstrated in relation to ozone exposure. The level and pattern of ozone exposure used in this experiment had no demonstrable adverse effects on the immune responses necessary to limit and terminate rhinovirus infection of the upper respiratory tract.

  17. Experimental rhinovirus infection in human volunteers exposed to ozone.

    Science.gov (United States)

    Henderson, F W; Dubovi, E J; Harder, S; Seal, E; Graham, D

    1988-05-01

    We studied 24 young adult male volunteers experimentally inoculated with type 39 rhinovirus to determine whether the course of viral infection was modified by exposure to moderate levels of ozone (0.3 ppm for 6 h per day) over the 5 days after virus inoculation. No differences in rhinovirus titers in nasal secretions, recruitment of neutrophils into nasal secretions, levels of interferon in nasal lavage fluid, in vitro lymphocyte proliferative responses to rhinovirus antigen, or levels of convalescent serum neutralizing antibody to type 39 rhinovirus were demonstrated in relation to ozone exposure. The level and pattern of ozone exposure used in this experiment had no demonstrable adverse effects on the immune responses necessary to limit and terminate rhinovirus infection of the upper respiratory tract.

  18. Histopathological changes in sheep experimentally infected with Babesia ovis.

    Science.gov (United States)

    Habela, M A; Reina, D; Navarrete, I; Redondo, E; Hernández, S

    1991-01-01

    Histopathological study was made of 12 Merino sheep - five splenectomized and seven intact - experimentally infected with Babesia ovis. Non-purulent encephalitis; initially exudative and subsequently interstitial pneumonia; pericarditis, myocarditis and haemorrhagic endocarditis; centrilobular necrotic hepatitis; hyperplasia of the lymphoreticular system; necrosis and vascular changes in adrenal glands were observed. The kidney was the most severely affected organ, exhibiting acute tubular necrosis typical of kidney shock syndrome. The lesions observed were suggestive of hypovolemic shock culminating in haemorrhagic diathesis owing to consumptive coagulopathy. Additionally, the massive release of catabolites from lysis and necrosis apparently produced endotoxic shock.

  19. Treatment of pigs experimentally infected with Mycoplasma hyopneumoniae, Pasteurella multocida, and Actinobacillus pleuropneumoniae with various antibiotics.

    OpenAIRE

    Stipkovits, L.; Miller, D; Glavits, R; Fodor, L; Burch, D

    2001-01-01

    The authors have performed a comparative study of the efficacy of various in-feed medications for the treatment of 5- to 6-week-old specific pathogen-free (SPF) piglets experimentally infected on day 1 with Mycoplasma hyopneumoniae, on day 8 with Pasteurella multocida (serotype A), and on day 15 with Actinobacillus pleuropneumoniae (serotype 2). The treatment started on day 9 and continued for 12 consecutive days, then the piglets were euthanized for examination of macroscopic, histologic, an...

  20. Experimental Andes virus infection in deer mice: characteristics of infection and clearance in a heterologous rodent host.

    Directory of Open Access Journals (Sweden)

    Jessica R Spengler

    Full Text Available New World hantaviruses can cause hantavirus cardiopulmonary syndrome with high mortality in humans. Distinct virus species are hosted by specific rodent reservoirs, which also serve as the vectors. Although regional spillover has been documented, it is unknown whether rodent reservoirs are competent for infection by hantaviruses that are geographically separated, and known to have related, but distinct rodent reservoir hosts. We show that Andes virus (ANDV of South America, carried by the long tailed pygmy rice rat (Oligoryzomys longicaudatus, infects and replicates in vitro and in vivo in the deer mouse (Peromyscus maniculatus, the reservoir host of Sin Nombre virus (SNV, found in North America. In experimentally infected deer mice, viral RNA was detected in the blood, lung, heart and spleen, but virus was cleared by 56 days post inoculation (dpi. All of the inoculated deer mice mounted a humoral immune response by 14 dpi, and produced measurable amounts of neutralizing antibodies by 21 dpi. An up-regulation of Ccl3, Ccl4, Ccl5, and Tgfb, a strong CD4⁺ T-cell response, and down-regulation of Il17, Il21 and Il23 occurred during infection. Infection was transient with an absence of clinical signs or histopathological changes. This is the first evidence that ANDV asymptomatically infects, and is immunogenic in deer mice, a non-natural host species of ANDV. Comparing the immune response in this model to that of the immune response in the natural hosts upon infection with their co-adapted hantaviruses may help clarify the mechanisms governing persistent infection in the natural hosts of hantaviruses.

  1. Experimental neosporosis in bulls: parasite detection in semen and blood and specific antibody and interferon-gamma responses.

    Science.gov (United States)

    Serrano-Martínez, E; Ferre, I; Martínez, A; Osoro, K; Mateos-Sanz, A; Del-Pozo, I; Aduriz, G; Tamargo, C; Hidalgo, C O; Ortega-Mora, L M

    2007-04-01

    To investigate the presence of Neospora caninum in semen and blood, and the development of specific antibody and interferon-gamma (IFN-gamma) responses in experimentally infected bulls. Eight bulls were intravenously infected with 10(8) live N. caninum tachyzoites of NC-1 isolate. The presence of N. caninum in semen and blood was assessed using a nested-PCR procedure. PCR-positive semen samples were bioassayed using a BALB/c nu/nu mouse model. Specific anti-N. caninum antibody and IFN-gamma responses were also examined. In parallel, eight seronegative bulls were studied as non-infected controls. All bulls were monitored for 26 weeks. All eight experimentally infected bulls showed N. caninum DNA in their semen and/or blood samples at some time during the course of the study. Parasite load in semen ranged from 0.1 to 14.5 parasites/ml (mean 6.0). N. caninum could not be detected in BALB/c nu/nu mice inoculated with PCR-positive semen samples. A significant increase in mean serum specific IgM antibody response to N. caninum was detected between 10 and 28 days post-infection (p.i.). Serum specific IgG, IgG1, and IgG2 antibody levels in experimentally infected bulls were significantly different after 21, 10, and 14 days p.i. as compared to controls, respectively. Specific anti-N. caninum IgG were detected in seminal plasma from infected bulls and values obtained were different from controls after 25 days p.i. Mean specific IFN-gamma responses in experimentally infected bulls were significantly higher than controls 3 days p.i. This is the first study to report the presence of N. caninum DNA in the semen and blood of experimentally infected bulls. Our observations indicate an intermittent presence of N. caninum in low numbers in semen and associated with chronic stage of the infection. This study is also the first to report the detection of anti-N. caninum IgG in seminal plasma of experimentally infected bulls.

  2. Specific IgA antibodies in Mycoplasma pneumoniae infections

    Directory of Open Access Journals (Sweden)

    Gino Ciarrocchi

    2011-06-01

    Full Text Available Mycoplasma pneumoniae is the prevalent cause of community acquired pneumonia (CAP, especially in pediatric age. M. pneumoniae infection may presents a severe pulmonary disease whose clinical picture is undistinguishable from that of other pneumotropic agents.A rapid and suitable laboratory diagnosis mainly lies on serological test investigations. A total of 37 consecutive CAP pediatric and adult patients, and 102 subjets with suspected respiratory tract infections (SIR were enrolled and examined for specific IgA-, IgG-, IgM anti-M. pneumoniae antibodies using a rapid ELISA test (Mycoplasma Chorus-Diesse, and a two step ELISA test (MYP test-Savyon. Agreement of IgA, IgG, and IgM values were 96%, 64%, 100%, respectively. Among CAP patients, IgM was the prevalent marker (23/37; in this population, 12/23 pediatric patients were both IgM and IgA positives. Conversely, among adults, IgA antibodies were the most prevalent infection marker. Pediatric patients of both CAP and SIR population showed a similar serological picture; instead, all adult patients resulted as IgM negatives; IgA and IgG antibodies showed high positive values in 4/8, and in four old patients IgA was the alone infection marker. Although specific IgM antibodies detection remains the main serological sign of recent infection in pediatric age, the presence of IgA antibodies is a suitable tool to revealing the etiology of clinical picture in both pediatric and adult patients.

  3. Antibiotic Treatment Suppresses Rotavirus Infection and Enhances Specific Humoral Immunity

    Science.gov (United States)

    Uchiyama, Robin; Chassaing, Benoit; Zhang, Benyue; Gewirtz, Andrew T.

    2014-01-01

    Background. Rotavirus causes 500 000 deaths and millions of physician visits and hospitalizations per year, with worse outcomes and reduced vaccine efficacy in developing countries. We hypothesized that the gut microbiota might modulate rotavirus infection and/or antibody response and thus potentially play a role in such regional differences. Methods. The microbiota was ablated via germ-free or antibiotic approaches. Enhanced exposure to microbiota was achieved via low-dose dextran sodium sulfate (DSS) treatment. Rotavirus infection and replication was assessed by enzyme-linked immunosorbent assay (ELISA) and quantitative reverse-transcription polymerase chain reaction. Diarrhea was scored visually. Humoral responses to rotavirus were measured by ELISA and enzyme-linked immunosorbent spot assay. Results. Microbiota elimination delayed infection and reduced infectivity by 42%. Antibiotics did not alter ratios of positive-sense to negative-sense strands, suggesting that entry rather than replication was influenced. Antibiotics reduced the diarrhea incidence and duration, indicating that the reduction in the level of rotavirus antigen was biologically significant. Despite lowered antigen level, antibiotics resulted in a more durable rotavirus mucosal/systemic humoral response. Increased rotavirus antibody response durability correlated with increased small intestinal rotavirus-specific, immunoglobulin A–producing antibody-secreting cell concentration in antibiotic-treated mice. Conversely, DSS treatment impaired generation of rotavirus-specific antibodies. Conclusions. Microbiota ablation resulted in reduced rotavirus infection/diarrhea and a more durable rotavirus antibody response, suggesting that antibiotic administration before rotavirus vaccination could raise low seroconversion rates that correlate with the vaccine's inefficacy in developing regions. PMID:24436449

  4. The Pathology of Experimental Rhoodococcus equi infection in foals

    Directory of Open Access Journals (Sweden)

    Karima Al-Salihi

    2013-03-01

    Full Text Available The pathology of experimental Rhodococcus equi (R. equi infection in 2-8 weeks-old-foal is studied. For this purpose, twenty foals were divided into three groups, and given R. equi intratracheally (1st group, through gastric route (2nd group and through umbilicus by contamination (3rd group. A control group of foals were given a Phosphate buffered Saline (PBS. Pulmonary and intestinal lesions were seen in foals of all infected groups. Grossly, there were multiple, variable-sized abscesses diffusely scattered throughout the lung parenchyma, in addition to the presence of different stages of pneumonia with variable-sized areas of consolidation and emphysema. Intestinal lesions were evident as engorgement of mesenteric blood vessels, subserosal hemorrhages seen along the intestinal tract especially the small intestine, in addition to enlargement of lymph nodes (mesenteric, bronchial and mediastinal. Some lymph nodes were edematous, have circular foci of caseous necrosis and some of them were filled with yellowish, thick creamy pus. The microscopic lesions were basically similar in all foals of the experimental groups, but varied depending on the time of death or euthanasia and included: acute pulmonary congestion, acute suppurative broncho-pneumonia, chronic pyogranulomatous pneumonia, and emphysematous and atelectatic area. There were focal necrosis of the pulmonary parenchyma and numerous bacterial colonies seen free or as aggregates within the cytoplasm of many histiocytes. Also, there were focal interstitial thickening of the alveolar septae. The pleura and interlobular septae were thickened due to cellular infiltration.

  5. Improving Diagnosis and Treatment of Staphylococcus aureus Infections : Experimental Studies

    NARCIS (Netherlands)

    S. van den Berg (Sanne)

    2015-01-01

    markdownabstract__Abstract__ Staphylococcus aureus is an opportunistic pathogen that causes a variety of infections, ranging from mild skin infections like furuncles and impetigo, to severe, lifethreatening infections including endocarditis, osteomyelitis and pneumonia. Invasive infections are

  6. Antibody and inflammatory responses in laying hens with experimental primary infections of Ascaridia galli.

    Science.gov (United States)

    Marcos-Atxutegi, C; Gandolfi, B; Arangüena, T; Sepúlveda, R; Arévalo, M; Simón, F

    2009-04-06

    Ascaridia galli, an intestinal nematode that affects hens and other domestic and wild birds, causes economic losses in avian exploitations. The present work shows that A. galli stimulates a strong antibody response as well as an intense inflammatory reaction, in the intestinal mucous of experimentally infected Lohmann Brown laying hens. IgG antibodies against soluble extracts of A. galli embrionated eggs and adult worms, were detected in both blood and yolks eggs from infected hens during a period of 105 days after the infection. This indicates that hens transfer to their offspring a part of the IgG antibodies produced when they become infected. The antigens responsible for the stimulation of specific IgG were molecules of 30-34, 44-54 and 58-90 kDa, while in the yolk eggs of infected hens a reactivity directed against antigens of molecular weight (M(w)) lower than 50 kDa was detected. Histology revealed traumatic lesions with leukocyte infiltration, and inflammation of the intestinal wall of the infected hens after 105 days of initial infection. The possible influence of the immune and inflammatory response on the population dynamics of the parasite is discussed.

  7. Rational Discovery of T Helper Epitopes Specific for Bovine Infections with Mycobacterium avium ssp paratuberculosis

    DEFF Research Database (Denmark)

    Lundegaard, Claus; Aagaard, C.; Ussery, David

    2011-01-01

    severely interferes with animal welfare and effective eradication initiatives. Currently three strains of M. bovis and one MAP strain (K10) have been fully sequenced and deposited in NCBI genbank. We have sequenced a Danish clinical isolate, Ejlskov2007, which is not yet published. State of the art...... to peptides from any of the M. bovis strains according to available sequence data. Unique MAP specific predicted epitopes is selected and is to be synthesized as 15–20 aa peptides. In addition we will select peptides specifically from antigens, which have previously shown to induce a CD4+ T cell response......, again with the emphasis of avoiding similarities to M. bovis sequences. Blood from cattle experimentally infected with MAP will be used for proliferation and cytokine assays to determine if and which of the selected peptides that will be recognized specifically by CD4+ T cells from infected cattle...

  8. Cellular immune responses of the rat to experimental infection with Dermatophilus congolensis.

    Science.gov (United States)

    Woodman, J P; Morrow, A M; Heron, I

    1990-11-01

    The host cell-mediated immune response was examined following experimentally-induced infection of rats with Dermatophilus congolensis, the causal agent of the skin disease dermatophilosis. Mononuclear cells (MC) isolated from Wistar rats 10 days following the induction of a third infection underwent a strong and specific proliferative response, as assessed by a [3H]thymidine incorporation assay, when cultured with various concentrations of inactivated D. congolensis cocci. Using specific monoclonal antibodies in an indirect fluorescent antibody test, this in vitro response was found to be characterised by a large expansion of the W3/25 (T-helper phenotype) population to form 56% of the total. Finally, the primed and stimulated MC were assessed for their ability to produce factors capable of inhibiting macrophage migration. The culture supernatants of D. congolensis-stimulated MC from infected rats caused significant migration inhibition of normal rat peritoneal exudate cells, whilst the supernatants of similarly-stimulated MC from naive rats failed to cause significant inhibition. The results show that a MC subpopulation becomes primed following experimentally-induced infection with D. congolensis and becomes activated after subsequent, in vitro, exposure.

  9. Macrophage activation associated with chronic murine cytomegalovirus infection results in more severe experimental choroidal neovascularization.

    Directory of Open Access Journals (Sweden)

    Scott W Cousins

    Full Text Available The neovascular (wet form of age-related macular degeneration (AMD leads to vision loss due to choroidal neovascularization (CNV. Since macrophages are important in CNV development, and cytomegalovirus (CMV-specific IgG serum titers in patients with wet AMD are elevated, we hypothesized that chronic CMV infection contributes to wet AMD, possibly by pro-angiogenic macrophage activation. This hypothesis was tested using an established mouse model of experimental CNV. At 6 days, 6 weeks, or 12 weeks after infection with murine CMV (MCMV, laser-induced CNV was performed, and CNV severity was determined 4 weeks later by analysis of choroidal flatmounts. Although all MCMV-infected mice exhibited more severe CNV when compared with control mice, the most severe CNV developed in mice with chronic infection, a time when MCMV-specific gene sequences could not be detected within choroidal tissues. Splenic macrophages collected from mice with chronic MCMV infection, however, expressed significantly greater levels of TNF-α, COX-2, MMP-9, and, most significantly, VEGF transcripts by quantitative RT-PCR assay when compared to splenic macrophages from control mice. Direct MCMV infection of monolayers of IC-21 mouse macrophages confirmed significant stimulation of VEGF mRNA and VEGF protein as determined by quantitative RT-PCR assay, ELISA, and immunostaining. Stimulation of VEGF production in vivo and in vitro was sensitive to the antiviral ganciclovir. These studies suggest that chronic CMV infection may serve as a heretofore unrecognized risk factor in the pathogenesis of wet AMD. One mechanism by which chronic CMV infection might promote increased CNV severity is via stimulation of macrophages to make pro-angiogenic factors (VEGF, an outcome that requires active virus replication.

  10. [Experimental infection of goats with Schistosoma bovis and S. curassoni: comparative pathogenic effects].

    Science.gov (United States)

    Labbo, R; Boulanger, D; Brémond, P; Chippaux, J P

    2007-03-01

    Specific mortality and morbidity have been quantified in goats experimentally infected with Schistosoma bovis or S. curassoni strains from Niger. The study involved nine animals followed during 380 days after infection with, respectively, 1,800 or 2,400 cercariae. S. bovis was significatively more pathogenic than S. curossoni in terms of mortality, weight loss and packed cell volume decrease. In addition, the intensity of clinical symptoms was significatively and positively correlated to the levels of fecal egg excretion. Compared to non-infected controls, a growth differential of, respectively, 1,600 and 880 grams per month should incite to consider S. bovis and S. curassoni as parasites of serious economical impact in sahelian countries.

  11. Quantification of Pasteurella multocida in experimentally infected pigs using a real-time PCR assay.

    Science.gov (United States)

    Tocqueville, V; Kempf, I; Paboeuf, F; Marois-Créhan, C

    2017-06-01

    The aim of the study was to quantify Pasteurella multocida in experimentally infected pigs using a new qPCR assay based on the sodA gene and validated with 35 P. multocida strains, including strains isolated from pigs with pneumonia, clinically healthy pigs (nasal cavities), and human infections. The specificity of the test was verified with a collection of 60 strains of bacterial species other than P. multocida. The estimated detection threshold was 10 genome equivalents per microliter. The amplification efficiency and value of the correlation coefficients were 95.5% (±3.5%) and 0.995 (±0.005), respectively. Analysis of P. multocida suspensions in Buffered Peptone Water Broth and of samples prepared from lungs experimentally spiked with P. multocida revealed detection thresholds of 1.4CFU/μl and 8.4CFU/μl, respectively. In live pigs, experimentally-infected, approximately 10(5), 10(7) and 10(8)genomeequivalents/ml of P. multocida DNA was detected on Day 8 post-infection in the nasal cavities, tonsils and trachea samples, respectively. In dead pigs, approximatively 10(7)genomeequivalents/ml of P. multocida DNA was detected in the lung tissue with pneumonia. The qPCR assay's diagnostic specificity and sensitivity were 100% and 96%, respectively. This new qPCR assay should be a very useful tool for controlling enzootic pneumonia and studying the dynamics of infections in pig herds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Electromagnetic radiation influence on clinical course of experimental wound infection

    Directory of Open Access Journals (Sweden)

    Pronina Е.А.

    2010-09-01

    Full Text Available The article gives close attention to the study of electromagnetic radiation influence (EMR at the frequency of molecular spectrum absorption and radiation (MSAR of nitric oxide (150 GHz and atmospheric oxygen (129 GHz on the clinical course of experimental wound infection caused by antibiotic-sensitive and antibiotic-resistant strains of Pseudomonas aeruginosa. The panoramic spectrometric measuring complex, developed in Saratov Scientific Research Institute of Measuring Equipment was used while carrying out the research. Electromagnetic vibrations of extremely high frequencies were stimulated in this complex imitating the atmospheric oxygen and nitric oxide absorption and radiation molecular spectrum structure. The experiments proved the fact that exposure to radiation at the frequency of molecular spectrum absorption and radiation (MSAR of nitric oxide and atmospheric oxygen had positive impact on the course of traumatic process

  13. Specific depletion of Ly6C(hi inflammatory monocytes prevents immunopathology in experimental cerebral malaria.

    Directory of Open Access Journals (Sweden)

    Beatrix Schumak

    Full Text Available Plasmodium berghei ANKA (PbA infection of C57BL/6 mice leads to experimental cerebral malaria (ECM that is commonly associated with serious T cell mediated damage. In other parasitic infection models, inflammatory monocytes have been shown to regulate Th1 responses but their role in ECM remains poorly defined, whereas neutrophils are reported to contribute to ECM immune pathology. Making use of the recent development of specific monoclonal antibodies (mAb, we depleted in vivo Ly6C(hi inflammatory monocytes (by anti-CCR2, Ly6G+ neutrophils (by anti-Ly6G or both cell types (by anti-Gr1 during infection with Ovalbumin-transgenic PbA parasites (PbTg. Notably, the application of anti-Gr1 or anti-CCR2 but not anti-Ly6G antibodies into PbTg-infected mice prevented ECM development. In addition, depletion of Ly6C(hi inflammatory monocytes but not neutrophils led to decreased IFNγ levels and IFNγ+CD8+ T effector cells in the brain. Importantly, anti-CCR2 mAb injection did not prevent the generation of PbTg-specific T cell responses in the periphery, whereas anti-Gr1 mAb injection strongly diminished T cell frequencies and CTL responses. In conclusion, the specific depletion of Ly6C(hi inflammatory monocytes attenuated brain inflammation and immune cell recruitment to the CNS, which prevented ECM following Plasmodium infection, pointing out a substantial role of Ly6C+ monocytes in ECM inflammatory processes.

  14. Age-dependent differences in cytokine and antibody responses after experimental RSV infection in a bovine model

    DEFF Research Database (Denmark)

    Grell, S.N.; Riber, Ulla; Tjørnehøj, Kirsten

    2005-01-01

    Respiratory syncytial virus (RSV) causes severe respiratory disease in both infants and calves. As in humans, bovine RSV (BRSV) infections are most severe in the first 6 months of life. In this study, experimental infection with BRSV was performed in calves aged 1-5, 9-16 or 32-37 weeks. Compared...... to younger animals, older calves showed significantly less fever and lower TNFa. levels and less virus-specific IFN gamma release. In addition, blood from older animals had more mononuclear cells, more B cells and stronger BRSV-specific IgA and neutralising antibody responses to infection. A strong...

  15. Experimental infections with Mycoplasma agalactiae identify key factors involved in host-colonization.

    Directory of Open Access Journals (Sweden)

    Eric Baranowski

    Full Text Available Mechanisms underlying pathogenic processes in mycoplasma infections are poorly understood, mainly because of limited sequence similarities with classical, bacterial virulence factors. Recently, large-scale transposon mutagenesis in the ruminant pathogen Mycoplasma agalactiae identified the NIF locus, including nifS and nifU, as essential for mycoplasma growth in cell culture, while dispensable in axenic media. To evaluate the importance of this locus in vivo, the infectivity of two knock-out mutants was tested upon experimental infection in the natural host. In this model, the parental PG2 strain was able to establish a systemic infection in lactating ewes, colonizing various body sites such as lymph nodes and the mammary gland, even when inoculated at low doses. In these PG2-infected ewes, we observed over the course of infection (i the development of a specific antibody response and (ii dynamic changes in expression of M. agalactiae surface variable proteins (Vpma, with multiple Vpma profiles co-existing in the same animal. In contrast and despite a sensitive model, none of the knock-out mutants were able to survive and colonize the host. The extreme avirulent phenotype of the two mutants was further supported by the absence of an IgG response in inoculated animals. The exact role of the NIF locus remains to be elucidated but these data demonstrate that it plays a key role in the infectious process of M. agalactiae and most likely of other pathogenic mycoplasma species as many carry closely related homologs.

  16. Experimental Infections with Mycoplasma agalactiae Identify Key Factors Involved in Host-Colonization

    Science.gov (United States)

    Baranowski, Eric; Bergonier, Dominique; Sagné, Eveline; Hygonenq, Marie-Claude; Ronsin, Patricia; Berthelot, Xavier; Citti, Christine

    2014-01-01

    Mechanisms underlying pathogenic processes in mycoplasma infections are poorly understood, mainly because of limited sequence similarities with classical, bacterial virulence factors. Recently, large-scale transposon mutagenesis in the ruminant pathogen Mycoplasma agalactiae identified the NIF locus, including nifS and nifU, as essential for mycoplasma growth in cell culture, while dispensable in axenic media. To evaluate the importance of this locus in vivo, the infectivity of two knock-out mutants was tested upon experimental infection in the natural host. In this model, the parental PG2 strain was able to establish a systemic infection in lactating ewes, colonizing various body sites such as lymph nodes and the mammary gland, even when inoculated at low doses. In these PG2-infected ewes, we observed over the course of infection (i) the development of a specific antibody response and (ii) dynamic changes in expression of M. agalactiae surface variable proteins (Vpma), with multiple Vpma profiles co-existing in the same animal. In contrast and despite a sensitive model, none of the knock-out mutants were able to survive and colonize the host. The extreme avirulent phenotype of the two mutants was further supported by the absence of an IgG response in inoculated animals. The exact role of the NIF locus remains to be elucidated but these data demonstrate that it plays a key role in the infectious process of M. agalactiae and most likely of other pathogenic mycoplasma species as many carry closely related homologs. PMID:24699671

  17. SPECIFIC CONSTITUTIONAL FEATURES OF CHILDREN INFECTED WITH TUBERCULOSIS

    Directory of Open Access Journals (Sweden)

    Yu. A. Yarovaya

    2017-01-01

    Full Text Available In order to define specific constitutional features of the children infected with tuberculosis 222 children in the age from 1 to 14 years old have been examined: 106 children with active tuberculosis; 54 children with remaining post-tuberculosis changes; 62 children infected with tuberculous mycobacteria. The following types of diatheses were identified: lymphohypoplastic, allergic, neuroarthritic, exudative-catarrhal. It has been found out that among those with active tuberculosis the children suffering from lymphohypoplastic and neuroarthritic diatheses prevail (17.0 ± 3.7%, and allergic diathesis is less common (10.4 ± 3.0% cases. Children with lymphohypoplastic diathesis have a complicated course of tuberculosis (27.8 ± 10.6% and more intensive intoxication syndrome (55.6 ± 11.7%. The frequency of allergic diathesis is higher in the children with remaining post-tuberculosis changes (29.6 ± 6.2% and those infected with tuberculosis (33.8 ± 6.1% compared to children with active tuberculosis (10.4 ± 3.0%.

  18. Influence of body condition on influenza a virus infection in mallard ducks: Experimental infection data

    Science.gov (United States)

    Arsnoe, D.M.; Ip, Hon S.; Owen, J.C.

    2011-01-01

    Migrating waterfowl are implicated in the global spread of influenza A viruses (IAVs), and mallards (Anas platyrhynchos) are considered a particularly important IAV reservoir. Prevalence of IAV infection in waterfowl peaks during autumn pre-migration staging and then declines as birds reach wintering areas. Migration is energetically costly and birds often experience declines in body condition that may suppress immune function. We assessed how body condition affects susceptibility to infection, viral shedding and antibody production in wild-caught and captive-bred juvenile mallards challenged with low pathogenic avian influenza virus (LPAIV) H5N9. Wild mallards (n = 30) were separated into three experimental groups; each manipulated through food availability to a different condition level (-20%, -10%, and normal ??5% original body condition), and captive-bred mallards (n = 10) were maintained at normal condition. We found that wild mallards in normal condition were more susceptible to LPAIV infection, shed higher peak viral loads and shed viral RNA more frequently compared to birds in poor condition. Antibody production did not differ according to condition. We found that wild mallards did not differ from captive-bred mallards in viral intensity and duration of infection, but they did exhibit lower antibody titers and greater variation in viral load. Our findings suggest that reduced body condition negatively influences waterfowl host competence to LPAIV infection. This observation is contradictory to the recently proposed condition-dependent hypothesis, according to which birds in reduced condition would be more susceptible to IAV infection. The mechanisms responsible for reducing host competency among birds in poor condition remain unknown. Our research indicates body condition may influence the maintenance and spread of LPAIV by migrating waterfowl. ?? 2011 Arsnoe et al.

  19. Prevalence of type-specific HPV infection in Uruguay.

    Science.gov (United States)

    Berois, Nora; Heard, Isabelle; Fort, Zoraida; Alonso, Rafael; Sica, Adela; Moerzinger, Patricia; Rodriguez, Guillermo; Sancho-Garnier, Hélène; Osinaga, Eduardo; Favre, Michel

    2014-04-01

    The aim of this work was to describe the prevalence of type-specific Human papillomavirus (HPV) infection in women attending organized cervical cancer screening program in Uruguay. Nine hundred sixty-five liquid cervical cell samples obtained after collection of cervical smears for cytology were assessed for HPV DNA using the Papillocheck system (Greiner BioOne). The overall prevalence of High-Risk (HR) HPV infections was 20.8% and increased from 16.5% in women with normal cytology to 93.3% in HSIL. Prevalence of HPV 16 and/or 18 was 6.3% and HPV 16 was the most prevalent genotype in normal cytology (3.6%). The five most prevalent genotypes were HPV 16, 31, 51, 56, and 39. The overall prevalence peaked below age 30. This study provides essential baseline information at national level on type-specific HPV prevalence in Uruguay before the introduction of HPV vaccination. It documents the current prevalence of each of the oncogenic genotypes in a population attending cervical cancer screening program, suggesting that at least 64.7% of high risk lesions are potentially preventable by available HPV vaccines, and possibly augmentable if cross-protection against non-vaccine HPV types 31, 33, and 45 is confirmed. © 2013 Wiley Periodicals, Inc.

  20. Carbohydrate-rich high-molecular-mass antigens are strongly recognized during experimental Histoplasma capsulatum infection

    Directory of Open Access Journals (Sweden)

    Fabrine Sales Massafera Tristão

    2012-04-01

    Full Text Available INTRODUCTION: During histoplasmosis, Histoplasma capsulatum soluble antigens (CFAg can be naturally released by yeast cells. Because CFAg can be specifically targeted during infection, in the present study we investigated CFAg release in experimental murine histoplasmosis, and evaluated the host humoral immune response against high-molecular-mass antigens (hMMAg. >150 kDa, the more immunogenic CFAg fraction. METHODS: Mice were infected with 2.2x10(4 H. capsulatum IMT/HC128 yeast cells. The soluble CFAg, IgG anti-CFAg, IgG anti-hMMAg, and IgG-hMMAg circulating immune complexes (CIC levels were determined by enzymelinked immunosorbent assay, at days 0, 7, 14, and 28 post-infection. RESULTS: We observed a progressive increase in circulating levels of CFAg, IgG anti-CFAg, IgG anti-hMMAg, and IgG-hMMAg CIC after H. capsulatum infection. The hMMAg showed a high percentage of carbohydrates and at least two main immunogenic components. CONCLUSIONS: We verified for the first time that hMMAg from H. capsulatum IMT/HC128 strain induce humoral immune response and lead to CIC formation during experimental histoplasmosis.

  1. Experimental basis for the clinical epidemiology of fungal infections. A review.

    Science.gov (United States)

    Schaffner, A

    1989-10-01

    Based on the concept that the agents of deep fungal infections can be divided into primary pathogens and opportunists the experimental basis for the clinical epidemiology of mycoses is outlined. Kinetics of experimental infections with opportunists and primary pathogens discriminate between the two fungal categories. Natural resistance eliminates opportunists and prevents the establishment of progressive infection in the normal host. Primary pathogens call upon mechanisms of adoptive cell mediated immunity for their control. Therefore athymic mice which are not more susceptible to opportunists than control mice, cannot control infection with primary pathogens. In order to induce comparable overwhelming opportunistic mycoses with reasonable challenge doses, non-specific phagocytic resistance has to be eliminated. In agreement with in vivo studies, in vitro studies of the susceptibility of fungi to killing by phagocytes point out, that the susceptibility of the tissue phase of fungi to killing by "immunologically unarmed" phagocytes discriminates between opportunists and primary pathogens. In order to restrain primary pathogenic fungi, phagocytes have also in vitro to call upon adoptive, T cell-dependent immune mechanisms, which appear superfluous for control of opportunists. This difference explains the discrepant opportunistic proclivities of the two fungal categories. Patients with defective phagocytic defenses are prone to opportunistic mycoses, while deficient cell mediated immunity results in a greater vulnerability to primary pathogens.

  2. Specifics of phytomass combustion in small experimental device

    Directory of Open Access Journals (Sweden)

    Lenhard Richard

    2015-01-01

    Full Text Available A wood pellet combustion carries out with high efficiency and comfort in modern pellet boilers. These facts help to increase the amount of installed pellet boilers in households. The combustion process quality depends besides the combustion conditions also on the fuel quality. The wood pellets, which don`t contain the bark and branches represent the highest quality. Because of growing pellet demand, an herbal biomass (phytomass, which is usually an agricultural by-product becomes economically attractive for pellet production. Although the phytomass has the net calorific value relatively slightly lower than the wood biomass, it is often significantly worse in view of the combustion process and an emission production. The combustion of phytomass pellets causes various difficulties in small heat sources, mainly due to a sintering of fuel residues. We want to avoid the ash sintering by a lowering of temperature in the combustion chamber below the ash sintering temperature of phytomass via the modification of a burner design. For research of the phytomass combustion process in the small boilers is constructed the experimental combustion device. There will investigate the impact of cooling intensity of the combustion chamber on the combustion process and emissions. Arising specific requirements from the measurement will be the basis for the design of the pellet burner and for the setting of operating parameters to the trouble-free phytomass combustion was guaranteed.

  3. Antibody response against Trichinella spiralis in experimentally infected rats is dose dependent

    Science.gov (United States)

    2011-01-01

    Domestic pigs are the main representatives of the domestic cycle of Trichinella spiralis that play a role in transmission to humans. In Europe, backyard pigs of small household farms are the most important risks for humans to obtain trichinellosis. Rats might play a role in the transmission of Trichinella spiralis from domestic to sylvatic animals and vice versa. In order to be able to investigate the role of wild rats in the epidemiology of T. spiralis in The Netherlands, we studied the dynamics of antibody response after T. spiralis infections in experimental rats, using infection doses ranging from very low (10 muscle larvae, ML, per rat) to very high (16 000 ML per rat). To evaluate the feasibility of rats surviving high infection doses with T. spiralis, clinical and pathological parameters were quantified. Serological tools for detecting T. spiralis in rats were developed to quantitatively study the correlation between parasite load and immunological response. The results show that an infection dose-dependent antibody response was developed in rats after infection with as low as 10 ML up to a level of 10 000 ML. A positive correlation was found between the number of recovered ML and serum antibody levels, although specific measured antibody levels correspond to a wide range of LPG values. Serum antibodies of rats that were infected even with 10 or 25 ML could readily be detected by use of the T. spiralis western blot 2 weeks post infection. We conclude that based on these low infection doses, serologic tests are a useful tool to survey T. spiralis in wild rats. PMID:22129040

  4. Experimental infection and co-infection of dogs with Anaplasma platys and Ehrlichia canis: hematologic, serologic and molecular findings

    Directory of Open Access Journals (Sweden)

    Diniz PPVP

    2010-04-01

    Full Text Available Abstract Background Rhipicephalus sanguineus is a ubiquitous tick responsible for transmitting Ehrlichia canis and most likely Anaplasma platys to dogs, as either single or co-infections. The objective of this study was to assess the effects of either simultaneous or sequential experimental infections with E. canis and A. platys on hematological and serological parameters, duration of infection, and efficacy of doxycycline therapy in dogs infected with one or both organisms. Six dogs per group were either uninfected, A. platys infected, E. canis infected, A. platys and E. canis co-infected, A. platys infected and E. canis challenged or E. canis infected and A. platys challenged at day 112 post-infection (PI. Doxycycline treatment was initiated at 211 days PI, followed by dexamethasone immunosuppression beginning 410 days PI. Results Initially, transient decreases in hematocrit occurred in all groups infected with E. canis, but the mean hematocrit was significantly lower in the A. platys and E. canis co-infected group. All dogs except the controls developed marked thrombocytopenia after initial infection followed by gradually increased platelet counts by 112 days PI in groups with the single infections, while platelet counts remained significantly lower in the A. platys and E. canis co-infected group. Both sequential and simultaneous infections of A. platys and E. canis produced an enhanced humoral immune response to A. platys when compared to infection with A. platys alone. Likewise, co-infection with E. canis and A. platys resulted in a more persistent A. platys infection compared to dogs infected with A. platys only, but nearly all A. platys infected dogs became A. platys PCR negative prior to doxycycline treatment. E. canis infected dogs, whether single or co-infected, remained thrombocytopenic and E. canis PCR positive in blood for 420 days. When treated with doxycycline, all E. canis infected dogs became E. canis PCR negative and the

  5. Storage of gastrointestinal nematode infective larvae for species preservation and experimental infections.

    Science.gov (United States)

    Chylinski, C; Cortet, J; Sallé, G; Jacquiet, P; Cabaret, J

    2015-02-01

    Techniques to preserve the infective third-stage larvae (L3) of gastrointestinal nematodes are of considerable interest to preserve rare species and to maintain a stable source for routine experimental infections. This study compares the relative pros and cons of the two most common techniques, cryopreservation and refrigeration by comparing how they influence consequent infection outcome parameters in terms of life-history traits and fitness as a function of time using the gastrointestinal nematode of sheep Haemonchus contortus as a study species. Establishment capacity was found to be significantly reduced in cryopreserved stocks of L3 compared to refrigerated stocks, but this was followed by significant increases in their fecundity. Refrigeration did not affect L3 stocks consequent fitness by 16 months (the maximum examined) although they did incur a significant reduction in establishment, followed once again by an augmentation in fecundity. The study highlights potential areas for bias in comparing studies using L3 larvae maintained for different periods of time under different techniques.

  6. Dissemination of Salmonella enteritidis by experimentally-infected pigeons

    Directory of Open Access Journals (Sweden)

    ÁH Albuquerque

    2013-09-01

    Full Text Available Two groups of domestic pigeons (Columba livia were experimentally infected orally with doses of 9.5 x10(7 and 9.5 x10(9 CFU/mL (group A and B, respectively of a Salmonella Enteritidis (SE strain isolated from chickens. None of the used doses caused mortality of the inoculated birds; however, the pathogen was successfully recovered from the liver and spleen of group B birds on day 7 post-inoculation (dpi. Pathogen shedding, as evaluated through cloacal swabs, occurred in both groups until the 14th day of observation (p <0.05. Among all fecal samples collected from group B (n=4, three different birds shed the pathogen in their feces, out of which two were positive on 3 dpi and one on 7 dpi. The same number of fecal samples was evaluated in group A and only one bird shed the pathogen, on 7 and 14 dpi. The concentration of the microorganism in the feces was lower in group A than any sample from Group B. Salmonella Enteritidis isolated from chickens, when inoculated in pigeons, may be recovered from feces, cloacal swabs and organs, and these birds may contaminate poultry causing economic losses as well as posing a risk to the public health.

  7. Haematological changes in Nile tilapia experimentally infected with Enterococcus sp.

    Directory of Open Access Journals (Sweden)

    ML. Martins

    Full Text Available This study evaluated the haematological changes in Nile tilapia experimentally infected with 1 x 10³ and 1 x 10(6 colony-forming units (CFU/mL of Enterococcus sp. in the swim bladder. The experiment consisted of four treatments in triplicates: non-injected fish (NI; fish injected with 1 mL of sterile saline solution 0.65% (SAL; fish injected with 1 x 10³ and 1 x 10(6 CFU/mL of Enterococcus diluted in 1 mL sterile saline. Twenty-four hours after injection, the fish were anesthetized and the blood collected. The haematological tests included red blood cell (RBC and white blood cell (WBC counts, hematocrit, number of total thrombocytes, and differential counting of WBC. Fish injected with 1 x 10(6 CFU/mL of Enterococcus showed a higher number of thrombocytes than the other treatments. White blood cell and lymphocyte numbers increased significantly in fish injected with 1 x 10(6 CFU/mL of Enterococcus when compared to non-injected control. There was significant increase in the number of neutrophils in saline injected fish and reduced number of monocytes after injections with 1 x 10(6 CFU/mL of Enterococcus. Hematocrit increased in fish injected with 1 x 10³ and 1 x 10(6 CFU/mL of Enterococcus.

  8. Humoral immunity through immunoglobulin M protects mice from an experimental actinomycetoma infection by Nocardia brasiliensis.

    Science.gov (United States)

    Salinas-Carmona, Mario C; Pérez-Rivera, Isabel

    2004-10-01

    An experimental model of infection with Nocardia brasiliensis, used as an example of a facultative intracellular pathogen, was tested. N. brasiliensis was injected into the rear foot pads of BALB/c mice to establish an infection. Within 30 days, infected animals developed a chronic actinomycetoma infection. Batch cultures of N. brasiliensis were used to purify P61, P38, and P24 antigens; P61 is a catalase, and P38 is a protease with strong caseinolytic activity. Active and passive immunizations of BALB/c mice with these three purified soluble antigens were studied. Protection was demonstrated for actively immunized mice. However, immunity lasted only 30 days. Other groups of immunized mice were bled at different times, and their sera were passively transferred to naive recipients that were then infected with N. brasiliensis. Sera collected 5, 6, and 7 days after donor immunization conferred complete, long-lasting protection. The protective effect of passive immunity decreased when sera were collected 2 weeks after donor immunization. However, neither the early sera (1-, 2-, and 3-day sera) nor the later sera (30- or 45-day sera) prevented the infection. Hyperimmune sera with the highest levels of immunoglobulin G (IgG) to N. brasiliensis antigens did not protect at all. The antigens tested induced two IgM peaks. The first peak was present 3 days after immunization but was not antigen specific and did not transfer protection. The second peak was evident 7 days after immunization, was an IgM response, was antigen specific, and conferred protection. This results clearly demonstrate that IgM antibodies protect the host against a facultative intracellular bacterium.

  9. Pathology of experimental Escherichia coli infection in mice: a ...

    African Journals Online (AJOL)

    . Mice were sacrificed after 72hrs and the glands examined bacteriological and histologically. Positive bacteriological and histological results were required for a diagnosis of infection. The infective dose fifty (ID50) for the nine stereotypes ...

  10. Genetic resistance to experimental Cooperia oncophora infections in calves

    NARCIS (Netherlands)

    Albers, G.A.A.

    1981-01-01

    The variation in resistance of cattle to gastro-intestinal nematode infection was investigated in three experiments. Bull calves, aged three months and reared under uniform conditions, were artificially infected with infective larvae of Cooperia oncophora, a moderately

  11. Infectivity and temperature tolerance of non-encapsulating Trichinella zimbabwensis in experimentally infected red foxes (Vulpes vulpes)

    DEFF Research Database (Denmark)

    Hurníková, Z.; Dubinský, P.; Mukaratirwa, S.

    2004-01-01

    The non-encapsulating Trichinella zimbabwensis was evaluated for infectivity in red foxes (Vulpes vulpes), the larval distribution and cold tolerance in fox muscle tissue. Six red foxes were experimentally infected with T. zimbabwensis larvae. Five weeks after inoculation, muscle larvae were...... recovered from 9 different muscle types using artificial digestion method. The establishment of infection in all infected red foxes demonstrated the ability of T. zimbabwensis to complete its life cycle in a carnivore mammal host. The larvae recovered from fox muscle tissue were infective to mice, they have...

  12. Antibody dynamics in BRSV-infected Danish dairy herds as determined by isotype-specific immunoglobulins

    DEFF Research Database (Denmark)

    Uttenthal, Åse; Larsen, Lars Erik; Philipsen, J.S.

    2000-01-01

    Using specific ELISAs, antibody levels of four different isotypes to bovine respiratory syncytial virus (BRSV) were determined in calves, following experimental BRSV infection. Most calves experienced an increase in the specific IgM and IgG1 titres about 6-10 days after infection with BRSV. The Ig......M titre was transient showing positive titres for only 5-10 days, while specific IgG1 was present for a longer time. IgA was detected concomitantly with IgM but at a lower level. Production of IgG2 anti-BRSV antibodies was detected from 3 weeks after infection. In two closed herds, repeated blood......, another herd with acute BRSV was followed by weekly blood samples in six calves; in both herds IgM and IgG1 was detected shortly after the appearance of clinical signs. Serum samples from 50 Danish dairy herds (453 samples) were tested for immunoglobulins of the isotypes IgG1, IgG2 and IgM. The presence...

  13. Young Sprague Dawley rats infected by Plasmodium berghei: A relevant experimental model to study cerebral malaria.

    Directory of Open Access Journals (Sweden)

    Sokhna Keita Alassane

    Full Text Available Cerebral malaria (CM is the most severe manifestation of human malaria yet is still poorly understood. Mouse models have been developed to address the subject. However, their relevance to mimic human pathogenesis is largely debated. Here we study an alternative cerebral malaria model with an experimental Plasmodium berghei Keyberg 173 (K173 infection in Sprague Dawley rats. As in Human, not all infected subjects showed cerebral malaria, with 45% of the rats exhibiting Experimental Cerebral Malaria (ECM symptoms while the majority (55% of the remaining rats developed severe anemia and hyperparasitemia (NoECM. These results allow, within the same population, a comparison of the noxious effects of the infection between ECM and severe malaria without ECM. Among the ECM rats, 77.8% died between day 5 and day 12 post-infection, while the remaining rats were spontaneously cured of neurological signs within 24-48 hours. The clinical ECM signs observed were paresis quickly evolving to limb paralysis, global paralysis associated with respiratory distress, and coma. The red blood cell (RBC count remained normal but a drastic decrease of platelet count and an increase of white blood cell numbers were noted. ECM rats also showed a decrease of glucose and total CO2 levels and an increase of creatinine levels compared to control rats or rats with no ECM. Assessment of the blood-brain barrier revealed loss of integrity, and interestingly histopathological analysis highlighted cyto-adherence and sequestration of infected RBCs in brain vessels from ECM rats only. Overall, this ECM rat model showed numerous clinical and histopathological features similar to Human CM and appears to be a promising model to achieve further understanding the CM pathophysiology in Humans and to evaluate the activity of specific antimalarial drugs in avoiding/limiting cerebral damages from malaria.

  14. Young Sprague Dawley rats infected by Plasmodium berghei: A relevant experimental model to study cerebral malaria.

    Science.gov (United States)

    Keita Alassane, Sokhna; Nicolau-Travers, Marie-Laure; Menard, Sandie; Andreoletti, Olivier; Cambus, Jean-Pierre; Gaudre, Noémie; Wlodarczyk, Myriam; Blanchard, Nicolas; Berry, Antoine; Abbes, Sarah; Colongo, David; Faye, Babacar; Augereau, Jean-Michel; Lacroux, Caroline; Iriart, Xavier; Benoit-Vical, Françoise

    2017-01-01

    Cerebral malaria (CM) is the most severe manifestation of human malaria yet is still poorly understood. Mouse models have been developed to address the subject. However, their relevance to mimic human pathogenesis is largely debated. Here we study an alternative cerebral malaria model with an experimental Plasmodium berghei Keyberg 173 (K173) infection in Sprague Dawley rats. As in Human, not all infected subjects showed cerebral malaria, with 45% of the rats exhibiting Experimental Cerebral Malaria (ECM) symptoms while the majority (55%) of the remaining rats developed severe anemia and hyperparasitemia (NoECM). These results allow, within the same population, a comparison of the noxious effects of the infection between ECM and severe malaria without ECM. Among the ECM rats, 77.8% died between day 5 and day 12 post-infection, while the remaining rats were spontaneously cured of neurological signs within 24-48 hours. The clinical ECM signs observed were paresis quickly evolving to limb paralysis, global paralysis associated with respiratory distress, and coma. The red blood cell (RBC) count remained normal but a drastic decrease of platelet count and an increase of white blood cell numbers were noted. ECM rats also showed a decrease of glucose and total CO2 levels and an increase of creatinine levels compared to control rats or rats with no ECM. Assessment of the blood-brain barrier revealed loss of integrity, and interestingly histopathological analysis highlighted cyto-adherence and sequestration of infected RBCs in brain vessels from ECM rats only. Overall, this ECM rat model showed numerous clinical and histopathological features similar to Human CM and appears to be a promising model to achieve further understanding the CM pathophysiology in Humans and to evaluate the activity of specific antimalarial drugs in avoiding/limiting cerebral damages from malaria.

  15. Experimental cross-species infection of common marmosets by titi monkey adenovirus.

    Directory of Open Access Journals (Sweden)

    Guixia Yu

    Full Text Available Adenoviruses are DNA viruses that infect a number of vertebrate hosts and are associated with both sporadic and epidemic disease in humans. We previously identified a novel adenovirus, titi monkey adenovirus (TMAdV, as the cause of a fulminant pneumonia outbreak in a colony of titi monkeys (Callicebus cupreus at a national primate center in 2009. Serological evidence of infection by TMAdV was also found in a human researcher at the facility and household family member, raising concerns for potential cross-species transmission of the virus. Here we present experimental evidence of cross-species TMAdV infection in common marmosets (Callithrix jacchus. Nasal inoculation of a cell cultured-adapted TMAdV strain into three marmosets produced an acute, mild respiratory illness characterized by low-grade fever, reduced activity, anorexia, and sneezing. An increase in virus-specific neutralization antibody titers accompanied the development of clinical signs. Although serially collected nasal swabs were positive for TMAdV for at least 8 days, all 3 infected marmosets spontaneously recovered by day 12 post-inoculation, and persistence of the virus in tissues could not be established. Thus, the pathogenesis of experimental inoculation of TMAdV in common marmosets resembled the mild, self-limiting respiratory infection typically seen in immunocompetent human hosts rather than the rapidly progressive, fatal pneumonia observed in 19 of 23 titi monkeys during the prior 2009 outbreak. These findings further establish the potential for adenovirus cross-species transmission and provide the basis for development of a monkey model useful for assessing the zoonotic potential of adenoviruses.

  16. Immune responsiveness associated with experimental Encephalitozoon intestinalis infection in immunocompetent rats

    Directory of Open Access Journals (Sweden)

    Omalu ICJ

    2007-01-01

    Full Text Available Purpose: Microsporidial infections have been recognized as an increasingly important infection in immuncompromised patients, particularly those infected with HIV/AIDS. This study was designed to study immune responses associated with experimental Encephalitozoon intestinalis infection in immunocompetent rats. Materials and Methods: Thirty-four Rats in 3 groups, A (Control, B (Intraperitoneal and C (Oral were given injections of 0.5 ml of 2 x 10 6 of purified spores of Encephalitotozoon intestinalis spores and were observed for serum specific IgG for 21 days using both direct and indirect ELISA. Results: In indirect ELISA, specific lgG were detected on days 7, 14 and 21 for the group B rats and on day 21 for group C and in direct ELISA method, specific lgG were detected in-group B rats on days 7 and 21, for group C rats on day 21 only, while in the control rats, specific lgG were not detected. There was no significant difference between the direct and indirect methods (df=1, X 2 , P>0.05. E. intestinalis was observed in stool samples of rats in 1/12 (08.33% on days 14 and 21 in group B, and in 4/10 (33.33%, 3/10 (25.00% and 2/10 (16.67% on days 7, 14 and 21 respectively in group C. In group A, which is the control rats, no microsporidia were observed on days 0, 7, 14 and 21. Conclusions: There were no changes in the T-lymphocyte counts of rats prior to and after inoculation with spores. Extensive lesions were observed along the intestinal walls especially on the middle and lower sections of group C rats only.

  17. Influenza virus infection during pregnancy and in specific populations

    NARCIS (Netherlands)

    Meijer, WJ

    2016-01-01

    Influenza virus infection causes approximately 1 billion infections worldwide each year. These infections are usually self-limiting, but serious complications may occur, in particular in adults aged 65 years or older, patients with cardiovascular disease, asthma or autoimmune disorders and pregnant

  18. Helicobacter pylori infection reduces disease severity in an experimental model of multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Katherine eCook

    2015-02-01

    Full Text Available Recent research has demonstrated that infection with the bacterial pathogen Helicobacter pylori is less common amongst patients with multiple sclerosis (MS, an inflammatory demyelinating disease of the central nervous system (CNS. We compared the prevalence of H. pylori amongst MS patients and healthy controls, and also investigated the impact of this infection on an animal model for MS, experimental autoimmune encephalomyelitis (EAE.The H. pylori status of 71 MS patients and 42 healthy controls was determined by serology. Groups of C57BL/6 mice were infected with H. pylori, or given a placebo, prior to inducing EAE. Clinical scores were assessed for all mice, and spleens and spinal cord tissue were harvested. CD4+ T cell subsets were quantified by flow cytometry, and T cell proliferation assays were performed.In MS patients the seroprevalence of H. pylori was half that of healthy controls (p=0.018. Over three independent experiments, prior H. pylori infection had a moderate effect in reducing the severity of EAE (p = 0.012. In line with this, the antigen-specific T cell proliferative responses of infected animals were significantly reduced (p=0.001, and there was a 4-fold reduction in the number of CD4+ cells in the CNS. CD4+ populations in both the CNS and the spleens of infected mice also contained greatly reduced proportions of IFNγ+, IL-17+, T-bet+, and RORγt+ cells, but the proportions of Foxp3+ cells were equivalent. There were no differences in the frequency of splenic CD4+cells expressing markers of apoptosis between infected and uninfected animals.H. pylori was less prevalent amongst MS patients. In mice, the infection exerted some protection against EAE, inhibiting both Th1 and Th17 responses. This could not be explained by the presence of increased numbers of Foxp3+ regulatory T cells, or T cell apoptosis. This is the first direct experimental evidence showing that H. pylori may provide protection against inflammatory demyelination

  19. Response of Cytokines and Hydrogen Peroxide to Sporothrix schenckii Exoantigen in Systemic Experimental Infection.

    Science.gov (United States)

    Maia, Danielle Cardoso Geraldo; Gonçalves, Amanda Costa; Ferreira, Lucas Souza; Manente, Francine Alessandra; Portuondo, Deivys Leandro; Vellosa, José Carlos Rebuglio; Polesi, Marisa Campos; Batista-Duharte, Alexander; Carlos, Iracilda Zeppone

    2016-04-01

    The response of hydrogen peroxide (H2O2) and cytokines during an experimental sporotrichosis in male Swiss mice was assessed over a period of 10 weeks by monitoring macrophage activation challenged with exoantigen (ExoAg) from the fungus Sporothrix schenckii. The studied endpoints were: H2O2 production, fungal burden at spleen, apoptosis in peritoneal macrophages, and IL-1β, IL-6, IL-2, IL-10 production. During the two first weeks of infection was observed low burden of yeast in spleen and high response of H2O2, IL-2, and IL-1β. The weeks of highest fungal burden (fourth-sixth) coincided with major apoptosis in peritoneal macrophages, normal production of IL-6 and lower production of H2O2, IL-2, and IL-1β, suggesting a role for these three last in the early control of infection. On the other hand, IL-1β (but not IL-6) was recovered since the sixth week, suggesting a possible role in the late phase of infection, contributing to the fungal clearance in conjunction with the specific mechanisms. The IL-10 was elevated until the sixth, principally in the second week. These results evidences that ExoAg is involved in the host immune modulation, influencing the S. Schenckii virulence, and its role is related with the time of the infection in the model used.

  20. Implications for a regulated replication of Borna disease virus in brains of experimentally infected Lewis rats.

    Science.gov (United States)

    Porombka, Doris; Baumgärtner, Wolfgang; Eickmann, Markus; Herden, Christiane

    2008-04-01

    The neurotropic Borna disease virus (BDV) causes typically a persistent virus infection of the central nervous system. In order to investigate whether an adapted virus replication contributes to BDV persistence in vivo, a fast and reliable real-time RT-PCR assay was constructed to quantify the amounts of leader-containing (leBDV) as a marker for virus replication, genomic (vBDV) and nucleoprotein-(BDV-N +ssRNA)-specific RNA. Therefore, leBDV, vBDV and BDV-N +ssRNA values were determined in experimentally infected Lewis rats between 14 and 90 days post infection (dpi). Surprisingly low leBDV values were found compared to vBDV and the abundantly expressed BDV-N transcripts. vBDV multiplied only in the acute phase of infection followed by constant expression until 90 dpi. Ratios of vBDV to leBDV were 401:1 at 14 dpi and diminished to 209:1 at 90 dpi, indicating a regulated co-expression of replicative intermediates as a potential prerequisite for viral persistence.

  1. Susceptibility to Yersinia pestis experimental infection in wild Rattus rattus, reservoir of plague in Madagascar.

    Science.gov (United States)

    Tollenaere, C; Rahalison, L; Ranjalahy, M; Duplantier, J-M; Rahelinirina, S; Telfer, S; Brouat, C

    2010-06-01

    In Madagascar, the black rat, Rattus rattus, is the main reservoir of plague (Yersinia pestis infection), a disease still responsible for hundreds of cases each year in this country. This study used experimental plague challenge to assess susceptibility in wild-caught rats to better understand how R. rattus can act as a plague reservoir. An important difference in plague resistance between rat populations from the plague focus (central highlands) and those from the plague-free zone (low altitude area) was confirmed to be a widespread phenomenon. In rats from the plague focus, we observed that sex influenced plague susceptibility, with males slightly more resistant than females. Other individual factors investigated (weight and habitat of sampling) did not affect plague resistance. When infected at high bacterial dose (more than 10⁵ bacteria injected), rats from the plague focus died mainly within 3-5 days and produced specific antibodies, whereas after low-dose infection (plague resistance level and the course of infection in the black rat would contribute to a better understanding of plague circulation in Madagascar.

  2. Experimental infection of horses with West Nile virus.

    Science.gov (United States)

    Bunning, Michel L; Bowen, Richard A; Cropp, C Bruce; Sullivan, Kevin G; Davis, Brent S; Komar, Nicholas; Godsey, Marvin S; Baker, Dale; Hettler, Danielle L; Holmes, Derek A; Biggerstaff, Brad J; Mitchell, Carl J

    2002-04-01

    A total of 12 horses of different breeds and ages were infected with West Nile virus (WNV) via the bites of infected Aedes albopictus mosquitoes. Half the horses were infected with a viral isolate from the brain of a horse (BC787), and half were infected with an isolate from crow brain (NY99-6625); both were NY99 isolates. Postinfection, uninfected female Ae. albopictus fed on eight of the infected horses. In the first trial, Nt antibody titers reached >1:320, 1:20, 1:160, and 1:80 for horses 1 to 4, respectively. In the second trial, the seven horses with subclinical infections developed Nt antibody titers >1:10 between days 7 and 11 post infection. The highest viremia level in horses fed upon by the recipient mosquitoes was approximately 460 Vero cell PFU/mL. All mosquitoes that fed upon viremic horses were negative for the virus. Horses infected with the NY99 strain of WNV develop low viremia levels of short duration; therefore, infected horses are unlikely to serve as important amplifying hosts for WNV in nature.

  3. Experimental infection of Foxes with European bat Lyssaviruses type-1 and 2

    Directory of Open Access Journals (Sweden)

    Biarnais Mélanie

    2009-05-01

    Full Text Available Abstract Background Since 1954, there have been in excess of 800 cases of rabies as a result of European Bat Lyssaviruses types 1 and 2 (EBLV-1, EBLV-2 infection, mainly in Serotine and Myotis bats respectively. These viruses have rarely been reported to infect humans and terrestrial mammals, as the only exceptions are sheep in Denmark, a stone marten in Germany and a cat in France. The purpose of this study was to investigate the susceptibility of foxes to EBLVs using silver foxes (Vulpes vulpes as a model. Results Our experimental studies have shown that the susceptibility of foxes to EBLVs is low by the intramuscular (IM route, however, animals were sensitive to intracranial (IC inoculation. Mortality was 100% for both EBLV-1 (~4.5 logs and EBLV-2 (~3.0 logs delivered by the IC route. Virus dissemination and inflammatory infiltrate in the brain were demonstrated but virus specific neutralising antibody (VNA was limited (log(ED50 = 0.24–2.23 and 0.95–2.39 respectively for specific EBLV-1 and EBLV-2. Foxes were also susceptible, at a low level, to peripheral (IM infection (~3.0 logs with EBLV-1 but not EBLV-2. Three out of 21 (14.3% foxes developed clinical signs between 14 and 24 days post-EBLV-1 infection. None of the animals given EBLV-2 developed clinical disease. Conclusion These data suggest that the chance of a EBLV spill-over from bat to fox is low, but with a greater probability for EBLV-1 than for EBLV-2 and that foxes seem to be able to clear the virus before it reaches the brain and cause a lethal infection.

  4. Effect of Experimental Coccidiosis Infections on Body Weight Gain ...

    African Journals Online (AJOL)

    The pathological effect of coccidiosis on sperm production of the male chickens had not been previously studied. It is note-worthy that coccidiosis infection in broiler males showed no degenerative changes in the seminiferous tubules and testis. In both cross and longitudinal sections of the testis of the infected male, there ...

  5. Experimental infection of squirrel monkeys with nipah virus.

    Science.gov (United States)

    Marianneau, Philippe; Guillaume, Vanessa; Wong, Thong; Badmanathan, Munisamy; Looi, Ren Yih; Murri, Severine; Loth, Philippe; Tordo, Noel; Wild, Fabian; Horvat, Branka; Contamin, Hugues

    2010-03-01

    We infected squirrel monkeys (Saimiri sciureus) with Nipah virus to determine the monkeys' suitability for use as primate models in preclinical testing of preventive and therapeutic treatments. Infection of squirrel monkeys through intravenous injection was followed by high death rates associated with acute neurologic and respiratory illness and viral RNA and antigen production.

  6. Experimental criticality specifications. An annotated bibliography through 1977

    Energy Technology Data Exchange (ETDEWEB)

    Paxton, H.C. (comp.)

    1978-05-01

    The compilation of approximately 300 references gives sources of experimental criticality parameters of systems containing /sup 235/U, /sup 233/U, and /sup 239/Pu. The intent is to cover basic data for criticality safety applications. The references are arranged by subject.

  7. Fungus-Specific CD4 T Cells as Specific Sensors for Identification of Pulmonary Fungal Infections.

    Science.gov (United States)

    Scheffold, Alexander; Schwarz, Carsten; Bacher, Petra

    2018-02-01

    Patients with cystic fibrosis (CF) suffer from chronic lung infections, caused by bacterial, viral or fungal pathogens, which determine morbidity and mortality. The contribution of individual pathogens to chronic disease and acute lung exacerbations is often difficult to determine due to the complex composition of the lung microbiome in CF. In particular, the relevance of fungal pathogens in CF airways remains poorly understood due to limitations of current diagnostics to identify the presence of fungal pathogens and to resolve the individual host-pathogen interaction status. T-lymphocytes play an essential role in host defense against pathogens, but also in inappropriate immune reactions such as allergies. They have the capacity to specifically recognize and discriminate the different pathogens and orchestrate a diverse array of effector functions. Thus, the analysis of the fungus-specific T cell status of an individual can in principle provide detailed information about the identity of the fungal pathogen(s) encountered and the actual fungus-host interaction status. This may allow to classify patients, according to appropriate (protective) or inappropriate (pathology-associated) immune reactions against individual fungal pathogens. However, T cell-based diagnostics are currently not part of the clinical routine. The identification and characterization of fungus-specific T cells in health and disease for diagnostic purposes are associated with significant challenges. Recent technological developments in the field of fungus-specific T helper cell detection provide new insights in the host T cell-fungus interaction. In this review, we will discuss basic principles and the potential of T cell-based diagnostics, as well as the perspectives and further needs for use of T cells for improved clinical diagnostics of fungal diseases.

  8. Experimental infection of pregnant gilts with swine hepatitis E virus

    OpenAIRE

    Kasorndorkbua, Chaiyan; Thacker, Brad J.; Halbur, Patrick G.; Guenette, Denis K.; Buitenwerf, Ryan M.; Royer, Ryan L.; Meng, Xiang-Jin

    2003-01-01

    To determine the effect of swine hepatitis E virus (HEV) infection on pregnant gilts, their fetuses, and offspring, 12 gilts were intravenously inoculated with swine HEV. Six gilts, who were not inoculated, served as controls. All inoculated gilts became actively infected and shed HEV in feces, but vertical transmission was not detected in the fetuses. There was no evidence of clinical disease in the gilts or their offspring. Mild multifocal lymphohistiocytic hepatitis was observed in 4 of 12...

  9. Histopathological evaluation of the efficacy of antifungals for experimental Trichosporon bloodstream infection.

    Science.gov (United States)

    Sasai, Daisuke; Okubo, Yoichiro; Ishiwatari, Takao; Sugita, Takashi; Kaneko, Takehiko; Murayama, Somay Yamagata; Shimamura, Tsuyoshi; Shinozaki, Minoru; Hasegawa, Chikako; Mitsuda, Aki; Tochigi, Naobumi; Wakayama, Megumi; Nemoto, Tetsuo; Shibuya, Kazutoshi

    2013-01-01

    The efficacy of polyene macrolides to treat experimental Trichosporon bloodstream infection was evaluated by histopathological examination and viable cell counts in the kidneys of infected mice. Viable cell counts on the 5th day after infection confirmed that liposomal amphotericin B (L-AMB) is a more effective treatment than fluconazole (FLC) for mice infected with an azole-resistant strain of Trichosporon. Histological examination revealed that the administration of L-AMB induced a transformation from acute purulent inflammation caused by both azole-susceptible and -resistant strain infections to a chronic and subsiding form, whereas FLC failed to convert the acute inflammation induced by the azole-resistant strain to a subsiding form. Our results demonstrate that polyene macrolides can be used as an alternative therapy for infection of azole-resistant strains of Trichosporon and that histopathological evaluation is useful for elucidating the pathophysiology of an experimental Trichosporon infection.

  10. Avian influenza in shorebirds: experimental infection of ruddy turnstones (Arenaria interpres) with avian influenza virus

    Science.gov (United States)

    Hall, Jeffrey S.; Krauss, Scott; Franson, J. Christian; TeSlaa, Joshua L.; Nashold, Sean W.; Stallknecht, David E.; Webby, Richard J.; Webster, Robert G.

    2013-01-01

    Background: Low pathogenic avian influenza viruses (LPAIV) have been reported in shorebirds, especially at Delaware Bay, USA, during spring migration. However, data on patterns of virus excretion, minimal infectious doses, and clinical outcome are lacking. The ruddy turnstone (Arenaria interpres) is the shorebird species with the highest prevalence of influenza virus at Delaware Bay. Objectives: The primary objective of this study was to experimentally assess the patterns of influenza virus excretion, minimal infectious doses, and clinical outcome in ruddy turnstones. Methods: We experimentally challenged ruddy turnstones using a common LPAIV shorebird isolate, an LPAIV waterfowl isolate, or a highly pathogenic H5N1 avian influenza virus. Cloacal and oral swabs and sera were analyzed from each bird. Results: Most ruddy turnstones had pre-existing antibodies to avian influenza virus, and many were infected at the time of capture. The infectious doses for each challenge virus were similar (103·6–104·16 EID50), regardless of exposure history. All infected birds excreted similar amounts of virus and showed no clinical signs of disease or mortality. Influenza A-specific antibodies remained detectable for at least 2 months after inoculation. Conclusions: These results provide a reference for interpretation of surveillance data, modeling, and predicting the risks of avian influenza transmission and movement in these important hosts.

  11. Lipid A's structure mediates Neisseria gonorrhoeae fitness during experimental infection of mice and men.

    Science.gov (United States)

    Hobbs, Marcia M; Anderson, James E; Balthazar, Jacqueline T; Kandler, Justin L; Carlson, Russell W; Ganguly, Jhuma; Begum, Afrin A; Duncan, Joseph A; Lin, Jessica T; Sparling, P Frederick; Jerse, Ann E; Shafer, William M

    2013-11-19

    Phosphoethanolamine (PEA) on Neisseria gonorrhoeae lipid A influences gonococcal inflammatory signaling and susceptibility to innate host defenses in in vitro models. Here, we evaluated the role of PEA-decorated gonococcal lipid A in competitive infections in female mice and in male volunteers. We inoculated mice and men with mixtures of wild-type N. gonorrhoeae and an isogenic mutant that lacks the PEA transferase, LptA. LptA production conferred a marked survival advantage for wild-type gonococci in the murine female genital tract and in the human male urethra. Our studies translate results from test tube to animal model and into the human host and demonstrate the utility of the mouse model for studies of virulence factors of the human-specific pathogen N. gonorrhoeae that interact with non-host-restricted elements of innate immunity. These results validate the use of gonococcal LptA as a potential target for development of novel immunoprophylactic strategies or antimicrobial treatments. Gonorrhea is one of the most common bacterial sexually transmitted infections, and increasing antibiotic resistance threatens the use of currently available antimicrobial therapies. In this work, encompassing in vitro studies and in vivo studies of animal and human models of experimental genital tract infection, we document the importance of lipid A's structure, mediated by a single bacterial enzyme, LptA, in enhancing the fitness of Neisseria gonorrhoeae. The results of these studies suggest that novel agents targeting LptA may offer urgently needed prevention or treatment strategies for gonorrhea.

  12. Vaccine-mediated immune responses to experimental pulmonary Cryptococcus gattii infection in mice.

    Directory of Open Access Journals (Sweden)

    Ashok K Chaturvedi

    Full Text Available Cryptococcus gattii is a fungal pathogen that can cause life-threatening respiratory and disseminated infections in immune-competent and immune-suppressed individuals. Currently, there are no standardized vaccines against cryptococcosis in humans, underlying an urgent need for effective therapies and/or vaccines. In this study, we evaluated the efficacy of intranasal immunization with C. gattii cell wall associated (CW and/or cytoplasmic (CP protein preparations to induce protection against experimental pulmonary C. gattii infection in mice. BALB/c mice immunized with C. gattii CW and/or CP protein preparations exhibited a significant reduction in pulmonary fungal burden and prolonged survival following pulmonary challenge with C. gattii. Protection was associated with significantly increased pro-inflammatory and Th1-type cytokine recall responses, in vitro and increased C. gattii-specific antibody production in immunized mice challenged with C. gattii. A number of immunodominant proteins were identified following immunoblot analysis of C. gattii CW and CP protein preparations using sera from immunized mice. Immunization with a combined CW and CP protein preparation resulted in an early increase in pulmonary T cell infiltrates following challenge with C. gattii. Overall, our studies show that C. gattii CW and CP protein preparations contain antigens that may be included in a subunit vaccine to induce prolonged protection against pulmonary C. gattii infection.

  13. MRSA Infections in HIV-Infected People Are Associated with Decreased MRSA-Specific Th1 Immunity.

    Directory of Open Access Journals (Sweden)

    Netanya S Utay

    2016-04-01

    Full Text Available People with HIV infection are at increased risk for community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA skin and soft tissue infections (SSTIs. Lower CD4 T-cell counts, higher peak HIV RNA levels and epidemiological factors may be associated with increased risk but no specific immune defect has been identified. We aimed to determine the immunologic perturbations that predispose HIV-infected people to MRSA SSTIs. Participants with or without HIV infection and with MRSA SSTI, MRSA colonization or negative for MRSA were enrolled. Peripheral blood and skin biopsies from study participants were collected. Flow cytometry, flow cytometry with microscopy, multiplex assays of cell culture supernatants and immunohistochemistry were used to evaluate the nature of the immune defect predisposing HIV-infected people to MRSA infections. We found deficient MRSA-specific IFNγ+ CD4 T-cell responses in HIV-infected people with MRSA SSTIs compared to MRSA-colonized participants and HIV-uninfected participants with MRSA SSTIs. These IFNγ+ CD4 T cells were less polyfunctional in HIV-infected participants with SSTIs compared to those without SSTIs. However, IFNγ responses to cytomegalovirus and Mycobacterium avium antigens and MRSA-specific IL-17 responses by CD4 T cells were intact. Upon stimulation with MRSA, peripheral blood mononuclear cells from HIV-infected participants produced less IL-12 and IL-15, key drivers of IFNγ production. There were no defects in CD8 T-cell responses, monocyte responses, opsonization, or phagocytosis of Staphylococcus aureus. Accumulation of CD3 T cells, CD4 T cells, IL-17+ cells, myeloperoxidase+ neutrophils and macrophage/myeloid cells to the skin lesions were similar between HIV-infected and HIV-uninfected participants based on immunohistochemistry. Together, these results indicate that MRSA-specific IFNγ+ CD4 T-cell responses are essential for the control of initial and recurrent MRSA infections in HIV-infected

  14. [Experimental and natural infection with the enzootic leukosis virus of cattle].

    Science.gov (United States)

    Hofírek, B; Horín, P; Granátová, M; Machatková, M; Franz, J; Svoboda, I; Blecha, J

    1986-03-01

    A trial was performed with heifers at the age of six to seven months. The animals were experimentally infected with the lymphocytes of a virus-productive donor. Infection was produced in all the nine cases, as demonstrated by means of the positive syncytial test. As indicated by the results of the trial, the antibodies to the enzootic bovine leucosis virus (BLV) were produced soon after experimental infection. A high sensitivity of the serum-neutralization test and the ELISA method was demonstrated in this connection: by these methods, the antibodies were identified already two to three weeks after experimental infection whereas by the immunodiffusion test they could be detected only after five weeks. Twenty-four animals were exposed to natural contact infection. Within 270 days of the trial, the disease after contact was recorded only in one heifer out of the four that were in close contact with the experimentally infected animals. In this case, as compared with experimental infection, the antibodies were produced much later--after 85 to 93 days. Leucosis was recorded in none of the remaining animals. The reasons why such a favourable result was obtained were the thorough disinfection of the stables after blood collections and the strict observance of the aseptic conditions. The results of experimental infection in three cows were identical with those obtained in young cattle. In the experimentally infected dairy cows, antibodies in milk were determined by the ELISA method. As found, in milk the antibodies to BLV appear two to three weeks later than they do in serum. The ELISA method of BLV antibody detection can be used for the identification of infected animals in herds where enzootic bovine leucosis occurs.

  15. Using experimental human influenza infections to validate a viral dynamic model and the implications for prediction.

    Science.gov (United States)

    Chen, S C; You, S H; Liu, C Y; Chio, C P; Liao, C M

    2012-09-01

    The aim of this work was to use experimental infection data of human influenza to assess a simple viral dynamics model in epithelial cells and better understand the underlying complex factors governing the infection process. The developed study model expands on previous reports of a target cell-limited model with delayed virus production. Data from 10 published experimental infection studies of human influenza was used to validate the model. Our results elucidate, mechanistically, the associations between epithelial cells, human immune responses, and viral titres and were supported by the experimental infection data. We report that the maximum total number of free virions following infection is 10(3)-fold higher than the initial introduced titre. Our results indicated that the infection rates of unprotected epithelial cells probably play an important role in affecting viral dynamics. By simulating an advanced model of viral dynamics and applying it to experimental infection data of human influenza, we obtained important estimates of the infection rate. This work provides epidemiologically meaningful results, meriting further efforts to understand the causes and consequences of influenza A infection.

  16. Experimental evidence for sex-specific plasticity in adult brain.

    Science.gov (United States)

    Herczeg, Gábor; Gonda, Abigél; Balázs, Gergely; Noreikiene, Kristina; Merilä, Juha

    2015-01-01

    Plasticity in brain size and the size of different brain regions during early ontogeny is known from many vertebrate taxa, but less is known about plasticity in the brains of adults. In contrast to mammals and birds, most parts of a fish's brain continue to undergo neurogenesis throughout adulthood, making lifelong plasticity in brain size possible. We tested whether maturing adult three-spined sticklebacks (Gasterosteus aculeatus) reared in a stimulus-poor environment exhibited brain plasticity in response to environmental enrichment, and whether these responses were sex-specific, thus altering the degree of sexual size dimorphism in the brain. Relative sizes of total brain and bulbus olfactorius showed sex-specific responses to treatment: males developed larger brains but smaller bulbi olfactorii than females in the enriched treatment. Hence, the degree of sexual size dimorphism (SSD) in relative brain size and the relative size of the bulbus olfactorius was found to be environment-dependent. Furthermore, the enriched treatment induced development of smaller tecta optica in both sexes. These results demonstrate that adult fish can alter the size of their brain (or brain regions) in response to environmental stimuli, and these responses can be sex-specific. Hence, the degree of SSD in brain size can be environment-dependent, and our results hint at the possibility of a large plastic component to SSD in stickleback brains. Apart from contributing to our understanding of the processes shaping and explaining variation in brain size and the size of different brain regions in the wild, the results show that provision of structural complexity in captive environments can influence brain development. Assuming that the observed plasticity influences fish behaviour, these findings may also have relevance for fish stocking, both for economical and conservational purposes.

  17. Preferential infection and depletion of Mycobacterium tuberculosis-specific CD4 T cells after HIV-1 infection

    NARCIS (Netherlands)

    Geldmacher, Christof; Ngwenyama, Njabulo; Schuetz, Alexandra; Petrovas, Constantinos; Reither, Klaus; Heeregrave, Edwin J.; Casazza, Joseph P.; Ambrozak, David R.; Louder, Mark; Ampofo, William; Pollakis, Georgios; Hill, Brenna; Sanga, Erica; Saathoff, Elmar; Maboko, Leonard; Roederer, Mario; Paxton, William A.; Hoelscher, Michael; Koup, Richard A.

    2010-01-01

    HIV-1 infection results in the progressive loss of CD4 T cells. In this study, we address how different pathogen-specific CD4 T cells are affected by HIV infection and the cellular parameters involved. We found striking differences in the depletion rates between CD4 T cells to two common

  18. Cardiac plexus of dogs experimentally infected with Trypanosoma cruzi: inflammatory lesions and quantitative studies

    Directory of Open Access Journals (Sweden)

    Marcelo V. Caliari

    1995-03-01

    Full Text Available Qualitative and quantitative aspects of the superficial and profound cardiac plexus of dogs experimentally infected with Be-62 and Be-78 strains of Trypanosoma cruzi were studied. Animals were autopsied in the acute phase of infection. The inflammatory process, lesions and number of parasites were more intense and frequent in animals infected with the Be-78 strain than in those infected with Be-62. Despite this, no statistically significant differences could be found between the number of neuron bodies in the ganglia of infected and control dogs.

  19. Host-specific induction of Escherichia coli fitness genes during human urinary tract infection.

    Science.gov (United States)

    Subashchandrabose, Sargurunathan; Hazen, Tracy H; Brumbaugh, Ariel R; Himpsl, Stephanie D; Smith, Sara N; Ernst, Robert D; Rasko, David A; Mobley, Harry L T

    2014-12-23

    Uropathogenic Escherichia coli (UPEC) is the predominant etiological agent of uncomplicated urinary tract infection (UTI), manifested by inflammation of the urinary bladder, in humans and is a major global public health concern. Molecular pathogenesis of UPEC has been primarily examined using murine models of UTI. Translational research to develop novel therapeutics against this major pathogen, which is becoming increasingly antibiotic resistant, requires a thorough understanding of mechanisms involved in pathogenesis during human UTIs. Total RNA-sequencing (RNA-seq) and comparative transcriptional analysis of UTI samples to the UPEC isolates cultured in human urine and laboratory medium were used to identify novel fitness genes that were specifically expressed during human infection. Evidence for UPEC genes involved in ion transport, including copper efflux, nickel and potassium import systems, as key fitness factors in uropathogenesis were generated using an experimental model of UTI. Translational application of this study was investigated by targeting Cus, a bacterial copper efflux system. Copper supplementation in drinking water reduces E. coli colonization in the urinary bladder of mice. Additionally, our results suggest that anaerobic processes in UPEC are involved in promoting fitness during UTI in humans. In summary, RNA-seq was used to establish the transcriptional signature in UPEC during naturally occurring, community acquired UTI in women and multiple novel fitness genes used by UPEC during human infection were identified. The repertoire of UPEC genes involved in UTI presented here will facilitate further translational studies to develop innovative strategies against UTI caused by UPEC.

  20. Transcriptome-wide characterization of human cytomegalovirus in natural infection and experimental latency.

    Science.gov (United States)

    Cheng, Shu; Caviness, Katie; Buehler, Jason; Smithey, Megan; Nikolich-Žugich, Janko; Goodrum, Felicia

    2017-11-20

    The transcriptional program associated with herpesvirus latency and the viral genes regulating entry into and exit from latency are poorly understood and controversial. Here, we developed and validated a targeted enrichment platform and conducted large-scale transcriptome analyses of human cytomegalovirus (HCMV) infection. We used both an experimental hematopoietic cell model of latency and cells from naturally infected, healthy human subjects (clinical) to define the breadth of viral genes expressed. The viral transcriptome derived from experimental infection was highly correlated with that from clinical infection, validating our experimental latency model. These transcriptomes revealed a broader profile of gene expression during infection in hematopoietic cells than previously appreciated. Further, using recombinant viruses that establish a nonreactivating, latent-like or a replicative infection in CD34+ hematopoietic progenitor cells, we defined classes of low to moderately expressed genes that are differentially regulated in latent vs. replicative states of infection. Most of these genes have yet to be studied in depth. By contrast, genes that were highly expressed, were expressed similarly in both latent and replicative infection. From these findings, a model emerges whereby low or moderately expressed genes may have the greatest impact on regulating the switch between viral latency and replication. The core set of viral genes expressed in natural infection and differentially regulated depending on the pattern of infection provides insight into the HCMV transcriptome associated with latency in the host and a resource for investigating virus-host interactions underlying persistence.

  1. First attempt to produce experimental Campylobacter concisus infection in mice

    DEFF Research Database (Denmark)

    Aabenhus, R.; Stenram, U.; Andersen, L.P.

    2008-01-01

    AIM: To infect mice with atypical Campylobacter concisus (C. concisus) for the first time. METHODS: Three separate experiments were conducted in order to screen the ability of five clinical C. concisus isolates of intestinal origin and the ATCC 33237 type strain of oral origin to colonize...

  2. Experimental toxoplasma gondii infection in grey seals (Halichoerus grypus)

    DEFF Research Database (Denmark)

    Gajadhar, A. A.; Measures, L.; Forbes, L. B.

    2004-01-01

    Laboratory-reared animals were used to assess the susceptibility of seals (Halichoerus grypus) to Toxoplasma gondii infection. Four seals were each orally inoculated with 100 or 10,000 oocysts of T. gondii (VEG strain), and another 4 seals served as negative controls. Occasionally, mild behavioral...

  3. Progression of experimental chronic Aleutian mink disease virus infection

    DEFF Research Database (Denmark)

    Jensen, Trine Hammer; Chriél, Mariann; Hansen, Mette Sif

    2016-01-01

    Aleutian mink disease virus (AMDV) is found world-wide and has a major impact on mink health and welfare by decreasing reproduction and fur quality. In the majority of mink, the infection is subclinical and the diagnosis must be confirmed by serology or polymerase chain reaction (PCR). Increased...

  4. 0f chemotherapy in goats experimentally infected with

    African Journals Online (AJOL)

    'Y58' stock. The goats were monitored serologically by using antigen-ELISA and Antibody-ELISA before and after Berenil treatment for a period lasting about sixty two days. The mean prepatent period before trypanosomes were detected in their bloodstreams was five days post-infection; circulating antigens and antibodies ...

  5. Salmonella Enteritidis experimental infection in chickens: Effects of ...

    African Journals Online (AJOL)

    Salmonella enterica serovar Enteritidis is a food borne pathogen of humans causing food-poisoning and sometimes deaths. In order to control egg-borne transmission of Salmonella Enteritidis to humans, prompt and accurate detection of infected poultry flocks is essential. This paper examined the effects of challenge dose ...

  6. Histopathological changes during experimental infections of calves with Cooperia punctata.

    Science.gov (United States)

    Rodrigues, R R; Gennari, S M; Guerra, J L; Contieri, M B; Abdalla, A L; Vitti, D M S S

    2004-06-01

    Eleven male two-month-old Holstein calves were used to determine the pathological changes induced by a Cooperia punctata infection. After weaning, ten calves received a single oral dose of 45,000 C. punctata infective larvae. One calf remained as a non-infected control. Groups of two calves were killed on days 7, 14, 21, 28 and 35 post-infection (p.i.) for determination of worm burdens and histopathological evaluation. The small intestine was sub-divided into three sections of approximately equal length, and representative samples of mucosa were fixed in 10% formalin, cut, and stained with haematoxylin-eosin. Samples of intestinal contents and mucosal digests were taken and fixed in 10% formalin for an estimation of total worm burdens. An increase in the number of adult parasites and a decrease in the number of larvae were observed with time (P<0.001). A higher concentration of worms was found in the first segment of the small intestine during the five weeks of observation. Histology showed larvae in the intestinal mucosa on day 7 p.i., with a discrete increase in the cellular response. Adult worms and a marked cellular infiltrate with eosinophils and neutrophils were present on day 21 p.i., and these persisted until day 35 p.i. Microcysts resulting from worm destruction were observed from day 21 p.i.

  7. Experimental infection of Ethiopian highland sheep by different ...

    African Journals Online (AJOL)

    concentration, RBC counts and PCV values between exotic and indigenous animals but these physiological values were not recorded for different species and breeds of indigenous animals in Ethiopia. Information is also lacking about the effects of GI nematodes infection on these physiological parameters. (Bekele Tafesse ...

  8. Effects of experimental Neisseria meningitis W135 infection on ...

    African Journals Online (AJOL)

    This study investigated the effects of Neisseria menigitidis W135 infection via intraperitoneal route on plasma free tryptophan concentration, brain serotonin and 5-hydroxyindole acetic acid (5-HIAA) levels in albino mice fed normal and tryptophan-enriched diets. The kinetics of appearance of viable bacteria in the blood, ...

  9. Early stage leucocytosis in Nigerian pigs experimentally infected ...

    African Journals Online (AJOL)

    Sequential leukocyte changes associated with early phase of Trypanosoma brucei infection were investigated in indigenous Nigerian pigs. This was with the view to providing further hematological basis for effective chemotherapy of natural porcine trypanosomosis and to assessing the possible roles of leukocytes in ...

  10. Lung epithelial cells have virus-specific and shared gene expression responses to infection by diverse respiratory viruses.

    Science.gov (United States)

    VanLeuven, James T; Ridenhour, Benjamin J; Gonzalez, Andres J; Miller, Craig R; Miura, Tanya A

    2017-01-01

    The severity of respiratory viral infections is partially determined by the cellular response mounted by infected lung epithelial cells. Disease prevention and treatment is dependent on our understanding of the shared and unique responses elicited by diverse viruses, yet few studies compare host responses to viruses from different families while controlling other experimental parameters. Murine models are commonly used to study the pathogenesis of respiratory viral infections, and in vitro studies using murine cells provide mechanistic insight into the pathogenesis observed in vivo. We used microarray analysis to compare changes in gene expression of murine lung epithelial cells infected individually by three respiratory viruses causing mild (rhinovirus, RV1B), moderate (coronavirus, MHV-1), and severe (influenza A virus, PR8) disease in mice. RV1B infection caused numerous gene expression changes, but the differential effect peaked at 12 hours post-infection. PR8 altered an intermediate number of genes whose expression continued to change through 24 hours. MHV-1 had comparatively few effects on host gene expression. The viruses elicited highly overlapping responses in antiviral genes, though MHV-1 induced a lower type I interferon response than the other two viruses. Signature genes were identified for each virus and included host defense genes for PR8, tissue remodeling genes for RV1B, and transcription factors for MHV-1. Our comparative approach identified universal and specific transcriptional signatures of virus infection that can be used to distinguish shared and virus-specific mechanisms of pathogenesis in the respiratory tract.

  11. Host-pathogen interactions in specific pathogen-free chickens following aerogenous infection with Chlamydia psittaci and Chlamydia abortus.

    Science.gov (United States)

    Kalmar, Isabelle; Berndt, Angela; Yin, Lizi; Chiers, Koen; Sachse, Konrad; Vanrompay, Daisy

    2015-03-15

    Although Chlamydia (C.) psittaci infections are recognized as an important factor causing economic losses and impairing animal welfare in poultry production, the specific mechanisms leading to severe clinical outcomes are poorly understood. In the present study, we comparatively investigated pathology and host immune response, as well as systemic dissemination and expression of essential chlamydial genes in the course of experimental aerogeneous infection with C. psittaci and the closely related C. abortus, respectively, in specific pathogen-free chicks. Clinical signs appeared sooner and were more severe in the C. psittaci-infected group. Compared to C. abortus infection, more intense systemic dissemination of C. psittaci correlated with higher and faster infiltration of immune cells, as well as more macroscopic lesions and epithelial pathology, such as hyperplasia and erosion. In thoracic air sac tissue, mRNA expression of immunologically relevant factors, such as IFN-γ, IL-1β, IL-6, IL-17, IL-22, LITAF and iNOS was significantly stronger up-regulated in C. psittaci- than in C. abortus-infected birds between 3 and 14 days post-infection. Likewise, transcription rates of the chlamydial genes groEL, cpaf and ftsW were consistently higher in C. psittaci during the acute phase. These findings illustrate that the stronger replication of C. psittaci in its natural host also evoked a more intense immune response than in the case of C. abortus infection. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Regulatory T cell induction during Plasmodium chabaudi infection modifies the clinical course of experimental autoimmune encephalomyelitis.

    Directory of Open Access Journals (Sweden)

    Alessandro S Farias

    Full Text Available BACKGROUND: Experimental autoimmune encephalomyelitis (EAE is used as an animal model for human multiple sclerosis (MS, which is an inflammatory demyelinating autoimmune disease of the central nervous system characterized by activation of Th1 and/or Th17 cells. Human autoimmune diseases can be either exacerbated or suppressed by infectious agents. Recent studies have shown that regulatory T cells play a crucial role in the escape mechanism of Plasmodium spp. both in humans and in experimental models. These cells suppress the Th1 response against the parasite and prevent its elimination. Regulatory T cells have been largely associated with protection or amelioration in several autoimmune diseases, mainly by their capacity to suppress proinflammatory response. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we verified that CD4(+CD25(+ regulatory T cells (T regs generated during malaria infection (6 days after EAE induction interfere with the evolution of EAE. We observed a positive correlation between the reduction of EAE clinical symptoms and an increase of parasitemia levels. Suppression of the disease was also accompanied by a decrease in the expression of IL-17 and IFN-γ and increases in the expression of IL-10 and TGF-β1 relative to EAE control mice. The adoptive transfer of CD4(+CD25(+ cells from P. chabaudi-infected mice reduced the clinical evolution of EAE, confirming the role of these T regs. CONCLUSIONS/SIGNIFICANCE: These data corroborate previous findings showing that infections interfere with the prevalence and evolution of autoimmune diseases by inducing regulatory T cells, which regulate EAE in an apparently non-specific manner.

  13. Quantification of HTLV-I proviral load in experimentally infected rabbits

    Directory of Open Access Journals (Sweden)

    Kindt Thomas J

    2005-05-01

    Full Text Available Abstract Background Levels of proviral load in HTLV-1 infected patients correlate with clinical outcome and are reasonably prognostic. Adaptation of proviral load measurement techniques is examined here for use in an experimental rabbit model of HTLV-1 infection. Initial efforts sought to correlate proviral load with route and dose of inoculation and with clinical outcome in this model. These methods contribute to our continuing goal of using the model to test treatments that alleviate virus infection. Results A real-time PCR assay was used to measure proviral load in blood and tissue samples from a series of rabbits infected using HTLV-1 inocula prepared as either cell-free virus particles, infected cells or blood, or by naked DNA injection. Proviral loads from asymptomatically infected rabbits showed levels corresponding to those reported for human patients with clinically silent HTLV-1 infections. Proviral load was comparably increased in 50% of experimentally infected rabbits that developed either spontaneous benign or malignant tumors while infected. Similarly elevated provirus was found in organs of rabbits with experimentally induced acute leukemia/lymphoma-like disease. Levels of provirus in organs taken at necropsy varied widely suggesting that reservoirs of infections exist in non-lymphoid organs not traditionally thought to be targets for HTLV-1. Conclusion Proviral load measurement is a valuable enhancement to the rabbit model for HTLV-1 infection providing a metric to monitor clinical status of the infected animals as well as a means for the testing of treatment to combat infection. In some cases proviral load in blood did not reflect organ proviral levels, revealing a limitation of this method for monitoring health status of HTLV-1 infected individuals.

  14. Quantification of HTLV-I proviral load in experimentally infected rabbits

    Science.gov (United States)

    Zhao, Tong-Mao; Hague, Bishop; Caudell, David L; Simpson, R Mark; Kindt, Thomas J

    2005-01-01

    Background Levels of proviral load in HTLV-1 infected patients correlate with clinical outcome and are reasonably prognostic. Adaptation of proviral load measurement techniques is examined here for use in an experimental rabbit model of HTLV-1 infection. Initial efforts sought to correlate proviral load with route and dose of inoculation and with clinical outcome in this model. These methods contribute to our continuing goal of using the model to test treatments that alleviate virus infection. Results A real-time PCR assay was used to measure proviral load in blood and tissue samples from a series of rabbits infected using HTLV-1 inocula prepared as either cell-free virus particles, infected cells or blood, or by naked DNA injection. Proviral loads from asymptomatically infected rabbits showed levels corresponding to those reported for human patients with clinically silent HTLV-1 infections. Proviral load was comparably increased in 50% of experimentally infected rabbits that developed either spontaneous benign or malignant tumors while infected. Similarly elevated provirus was found in organs of rabbits with experimentally induced acute leukemia/lymphoma-like disease. Levels of provirus in organs taken at necropsy varied widely suggesting that reservoirs of infections exist in non-lymphoid organs not traditionally thought to be targets for HTLV-1. Conclusion Proviral load measurement is a valuable enhancement to the rabbit model for HTLV-1 infection providing a metric to monitor clinical status of the infected animals as well as a means for the testing of treatment to combat infection. In some cases proviral load in blood did not reflect organ proviral levels, revealing a limitation of this method for monitoring health status of HTLV-1 infected individuals. PMID:15910683

  15. Experimental treatment with sodium stibogluconate of hamsters infected with Leishmania (Leishmania) chagasi and Leishmania (Leishmania) amazonensis

    OpenAIRE

    Elizabeth M. de Figueiredo; Silva,Jaime Costa e; Brazil,Reginaldo P

    1999-01-01

    The present paper reports the experimental treatment of hamsters infected with Leishmania chagasi and Leishmania amazonensis with sodium stibogluconate (20mg/kg/day x 20 days). Only with L. chagasi did the treatment result in the complete elimination of parasites from the spleen. However, no parasitological cure was achieved in hamsters infected with L. amazonensis.O presente trabalho é um relato do tratamento experimental de hamsters infectado com Leishmania chagasi e Leishmania amazonensis ...

  16. Treatment of pigs experimentally infected with Mycoplasma hyopneumoniae, Pasteurella multocida, and Actinobacillus pleuropneumoniae with various antibiotics.

    Science.gov (United States)

    Stipkovits, L; Miller, D; Glavits, R; Fodor, L; Burch, D

    2001-10-01

    The authors have performed a comparative study of the efficacy of various in-feed medications for the treatment of 5- to 6-week-old specific pathogen-free (SPF) piglets experimentally infected on day 1 with Mycoplasma hyopneumoniae, on day 8 with Pasteurella multocida (serotype A), and on day 15 with Actinobacillus pleuropneumoniae (serotype 2). The treatment started on day 9 and continued for 12 consecutive days, then the piglets were euthanized for examination of macroscopic, histologic, and pathologic lesions and for the presence of mycoplasmas and bacteria in the lungs. Based on the results of clinical observations (respiratory signs, rectal temperature, body weight gain, and feed conversion efficiency), macroscopic and histologic lesions of the lungs, and microbiologic findings, the best results were obtained by treatment of pigs with Econor + chlortetracycline, followed by Tetramutin, Pulmotil, Cyfac, and lincomycin + chlortetracycline.

  17. Metabolomic profiling in cattle experimentally infected with Mycobacterium avium subsp. paratuberculosis.

    Directory of Open Access Journals (Sweden)

    Jeroen De Buck

    Full Text Available The sensitivity of current diagnostics for Johne's disease, a slow, progressing enteritis in ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP, is too low to reliably detect all infected animals in the subclinical stage. The objective was to identify individual metabolites or metabolite profiles that could be used as biomarkers of early MAP infection in ruminants. In a monthly follow-up for 17 months, calves infected at 2 weeks of age were compared with aged-matched controls. Sera from all animals were analyzed by 1H nuclear magnetic resonance spectrometry. Spectra were acquired, processed, and quantified for analysis. The concentration of many metabolites changed over time in all calves, but some metabolites only changed over time in either infected or non-infected groups and the change in others was impacted by the infection. Hierarchical multivariate statistical analysis achieved best separation between groups between 300 and 400 days after infection. Therefore, a cross-sectional comparison between 1-year-old calves experimentally infected at various ages with either a high- or a low-dose and age-matched non-infected controls was performed. Orthogonal Projection to Latent Structures Discriminant Analysis (OPLS DA yielded distinct separation of non-infected from infected cattle, regardless of dose and time (3, 6, 9 or 12 months after infection. Receiver Operating Curves demonstrated that constructed models were high quality. Increased isobutyrate in the infected cattle was the most important agreement between the longitudinal and cross-sectional analysis. In general, high- and low-dose cattle responded similarly to infection. Differences in acetone, citrate, glycerol and iso-butyrate concentrations indicated energy shortages and increased fat metabolism in infected cattle, whereas changes in urea and several amino acids (AA, including the branched chain AA, indicated increased protein turnover. In conclusion, metabolomics

  18. [Five steps to decreasing nosocomial infections in large immature premature infants: A quasi-experimental study].

    Science.gov (United States)

    García González, Ana; Leante Castellanos, José Luis; Fuentes Gutiérrez, Carmen; Lloreda García, José María; Fernández Fructuoso, José Ramón; Gómez Santos, Elisabet; García González, Verónica

    2017-07-01

    An evaluation is made of the impact of a series of five interventions on the incidence of hospital-related infections in a level iii neonatal unit. Quasi-experimental, pre-post intervention study, which included preterm infants weighing 1,500g at birth or delivered at <32 weeks gestation, admitted in the 12 months before and after the measures were implemented (January 2014). The measures consisted of: optimising hand washing, following a protocol for insertion and handling of central intravenous catheters, encouraging breastfeeding; applying a protocol for rational antibiotic use, and establishing a surveillance system for multi-resistant bacteria. The primary endpoint was to assess the incidence of hospital-acquired infections before and after implementing the interventions. Thirty-three matched patients were included in each period. There was an incidence of 8.7 and 2.7 hospital-related infections/1,000 hospital stay days in the pre- and post-intervention periods, respectively (P<.05). Additionally, patients in the treatment group showed a statistically-significant decrease in days on mechanical ventilation, use of blood products, and vasoactive drugs. The strategy, based on implementing five specific measures in a unit with a high rate of hospital-related infections, proved effective in reducing their incidence. This reduction could contribute to lowering the use of mechanical ventilation, blood products, and vasoactive drugs. Copyright © 2016 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  19. EXPERIMENTAL-INFECTION IN MICE WITH BACILLUS-LICHENIFORMIS

    DEFF Research Database (Denmark)

    Agerholm, J.S.; Jensen, H.E.; Jensen, N.E.

    1995-01-01

    The pathogenicity of Bacillus licheniformis was assessed in normal and immunodepressed BALB/c mice. The animals were challenged intravenously with 4 x 10(7) colony forming units of B, licheniformis (ATCC 14580) and both normal and immunodepressed mice were susceptible. However, the infection was ...... could be identified in tissue sections by immunostaining. Immunohistochemically, B, licheniformis was demonstrated in hepatic and pulmonic macrophages, and from some animals the bacteria were also reisolated....

  20. Food additives and Hymenolepis nana infection: an experimental study.

    Science.gov (United States)

    El-Nouby, Kholoud A; Hamouda, Hala E; Abd El Azeem, Mona A; El-Ebiary, Ahmad A

    2009-12-01

    The effect of sodium benzoate (SB) on the pathogenesis of Hymenolepis nana (H. nana) and its neurological manifestations was studied in the present work. One hundred and thirty five mice were classified into three groups. GI: received SB alone. GII: received SB before & after infection with H. nana and GIII: infected with H. nana. All groups were subjected to parasitological, histopathological, immunohistochemical and biochemical assays. The results revealed a significant decrease in IL-4 serum level with a significant increase in gamma amino butyric acid (GABA) and decrease in zinc brain levels in GI, while GII showed non significant increase in IL-4 level that resulted in a highly significant increase in the mean number of cysticercoids and adult worms with delayed expulsion as compared to GIII. This was reflected on histopathological and immunohistochemical changes in the brain. Also, there was a highly significant increase in GABA and decrease in zinc brain levels in GII to the degree that induced behavioral changes. This emphasizes the possible synergistic effect of SB on the neurological manifestations of H. nana and could, in part, explain the increased incidence of behavioral changes in children exposed to high doses of SB and unfortunately have H. nana infection.

  1. [Presence of autocomplementary RNA with viral specificity in cells infected with herpes virus].

    Science.gov (United States)

    Béchet, J M; Montagnier, L; Latarjet, R

    1975-01-13

    RNA from cells infected with Herpes simplex virus contain a higher percentage of double-stranded RNA than non-infected cells. This percentage increases three-fold upon self-annealing. The complementary RNA sequences were shown to be virus-specific by the following criteria: (1) high melting temperature than double-stranded RNA from non infected cells; (2) higher density in caesium sulphate; (3) specific hybridization with viral DNA.

  2. Use of Pathogen-Specific Antibody Biomarkers to Estimate Waterborne Infections in Population-Based Settings

    Science.gov (United States)

    Purpose of reviewThis review discusses the utility of pathogen-specific antibody biomarkers for improving estimates of the population burden of waterborne infections, assessing the fraction of infections that can be prevented by specific water treatments, and understanding transm...

  3. Alteration in the endogenous intestinal flora of swiss webster mice by experimental Angiostrongylus costaricensis infection

    Directory of Open Access Journals (Sweden)

    Vandack Nobre

    2004-11-01

    Full Text Available The association between worm infections and bacterial diseases has only recently been emphasized. This study examined the effect of experimental Angiostrongylus costaricensis infection on endogenous intestinal flora of Swiss Webster mice. Eight mice aging six weeks were selected for this experiment. Four were infected with A. costaricensis and the other four were used as controls. Twenty eight days after the worm infection, all mice in both groups were sacrificed and samples of the contents of the ileum and colon were obtained and cultured for aerobic and anaerobic bacteria. In the mice infected with A. costaricensis there was a significant increase in the number of bacteria of the endogenous intestinal flora, accompanied by a decrease in the number of Peptostreptococcus spp. This alteration in the intestinal flora of mice infected by the nematode may help to understand some bacterial infections described in humans.

  4. Coxsackievirus infections in pregnant women with a parallel experimental model infection showing possible effects on coarse of pregnancy

    Directory of Open Access Journals (Sweden)

    Borsanyiova M.

    2011-04-01

    Full Text Available Aim of our work was firstly to determine the prevalence of anti-coxsackievirus antibodies during pregnancy. 217 serum samples were tested for antibodies by virus neutralization test against coxsackieviruses (CV B1–B6, A7 and A9. The second aim was to investigate experimental transmission of virus to the fetus during pregnancy. Methods. Virus Neutralization Test, RT-PCR. Results. In the serological study, paired blood serum samples from 217 pregnant women were studied for antibodies against coxsackievirus serotypes (CVB1–CVB6, CVA7 and CVA9 in sera of pregnant women from selected areas of the Slovak Republic. Coxsackievirus B4 (CVB4 infection was most prevalent, followed by CVB3, CVA7, CVA9, CVB5, CVB2, CVB1 while coxsackievirus B6 (CVB6 was scarce. In 30 out of 217 cases (13.82 % current infection was recorded. In the experimental murine study, in the second week of gravidity we observed presence of enteroviral RNA in the placenta and the intestine of the dead fetuses of the mice. Conclusions. Anti-CV antibodies were prevalent in the pregnant mothers indicating circulation of these viruses in the population. Current infection was shown in 13.82 % of studied cases. Presence of virus RNA in the organs of the unborn fetuses in the experimental infection indicates the possibility of transfer of the coxsackievirus B4-E2 infection from mother to child during antenatal development

  5. Study of the pathogenic potential of Dientamoeba fragilis in experimentally infected mice

    Directory of Open Access Journals (Sweden)

    Eman K. El-Gayar

    2016-06-01

    Full Text Available Dientamoebafragilis (D. fragilis is a protozoan parasite whose pathogenic potential is still disputable. The aim of this study was to illustrate the pathogenicity of D. fragilis infection and to determine the infective dose for experimental mice infection. Three groups of mice (8/each were orally inoculated with in vitro cultured D. fragilis. The infected groups (G1- G3 received 103, 105 and 4 × 106 D. fragilis/0.5 ml culture, respectively. A control group (G4 only received parasite-free culture. Two weeks post-inoculation all mice were euthanized for histopathological examination. All mice of G3 (100% and three mice of G2 (37.5% were infected, and the results were confirmed by PCR and different staining methods. On the other hand, all mice from group G1 showed a completely negative result. Histopathological examination of the colon and caecum of the highly infected group G3 showed active colitis, with infiltration of mixed inflammatory cells such as eosinophils, neutrophils and lymphocytes within the lamina propria of the intestinal wall. The parasite was not invading the colonic mucosa. This study revealed that infection with D. fragilis is dose-dependent. Moreover, a dose of 105 D. fragilis/mouse or higher is necessary to infect mice through the oral route. In addition, this route of infection, although non-invasive, can induce severe inflammatory changes to the colonic and caecal mucosa in experimentally infected mice.

  6. Experimental Trypanosoma evansi infection in South American coati (Nasua nasua): hematological, biochemical and histopathological changes.

    Science.gov (United States)

    Herrera, H M; Alessi, A C; Marques, L C; Santana, A E; Aquino, L P C T; Menezes, R F; Moraes, M A V; Machado, R Z

    2002-03-01

    The course of an experimental Trypanosoma evansi infection in coatis (Nasua nasua, carnivora, Procyonidae) was followed for 262 days. Hematological analysis of the infected coatis revealed a marked decline in hemoglobin, packed-cell volume, and total erythrocyte count. An intense anemia followed the first wave of parasitemia and persisted until the end of the experimental period. Biochemical analysis showed increased serum levels of alanine aminotransferase and aspartate aminotransferase and decreased albumin. The main histopathological features consisted of myocarditis with the presence of degenerate cardiac fibers and meningoencephalitis. This study has shown that coatis infected with T. evansi develop a chronic disease.

  7. Brain infection following experimental Staphylococcus aureus sepsis in pigs

    DEFF Research Database (Denmark)

    Astrup, Lærke Boye; Iburg, Tine Moesgaard; Nielsen, Ole Lerberg

    2010-01-01

    Introduction: Sepsis is a major problem in humans and both the incidence and mortality is increasing. Multiple microabcesses can be found in the brain of septic patients. Staphylococcus aureus is one of the most common causes of sepsis and brain abscesses. S. aureus is also a frequent cause...... pigs were kept as controls. The pigs were euthanized in groups of four at either 6, 12, 24 or 48 h post infection. The brain was collected from all the animals and examined histologically. Results: All the inoculated pigs developed sepsis and 7 out of 12 animals had microabscesses in the prosencephalon...

  8. Experimental Infection of Cats and Dogs with West Nile Virus

    OpenAIRE

    Austgen, Laura E.; Bowen, Richard A.; Bunning, Michel L.; Davis, Brent S.; Mitchell, Carl J.; Chang, Gwong-Jen J.

    2004-01-01

    Domestic dogs and cats were infected by mosquito bite and evaluated as hosts for West Nile virus (WNV). Viremia of low magnitude and short duration developed in four dogs but they did not display signs of disease. Four cats became viremic, with peak titers ranging from 103.0 to 104.0 PFU/mL. Three of the cats showed mild, non-neurologic signs of disease. WNV was not isolated from saliva of either dogs or cats during the period of viremia. An additional group of four cats were exposed to WNV o...

  9. Immunodiagnosis of systemic aspergillosis. I. Antigenemia detected by radioimmunoassay in experimental infection. [/sup 125/I tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Weiner, M.H.; Coats-Stephen, M.

    1979-01-01

    Because systemic aspergillosis is difficult to diagnose ante mortem, a study to improve immunodiagnosis was undertaken in a rabbit model of disseminated infection. We found that the predominant humoral response of infected animals was directed against four Aspergillus antigens identified by crossed immunoelectrophoresis. One of these antigens, a cell-wall carbohydrate, was purified by gel-filtration chromatography and was used to develop a radiommunoassay. The sensitivity of this assay was increased by testing for serum-bound antigen as well as for free antigen. When the sensitivity of the RIA was evaluated in the animal model, antigenemia was detected in 78% of 51 rabbits with disseminated infection and ante mortem in 86% of 42 rabbits with lethal infection. By contrast, with immunoprecipitin analysis only eight of 51 rabbits were positive for antigen, and six of 51 rabbits were positive for Aspergillus antibody. The specificity of the RIA was also tested. Negative controls for antigen included sera from 76 normal rabbits and sera from 25 rabbits with systemic candidiasis. The Candida control group is pertinent because 48% of these rabbits had specific Candida antigenemia detected by a mannan RIA. This study demonstrates that Aspergillus antigenemia occurs during the course of experimental disseminated aspergillosis and illustrates the potential of an Aspergillus antigen RIA for sensitive, specific immunodiagnosis of human infections.

  10. Experimental infection of raccoons (Procyon lotor) with West Nile virus.

    Science.gov (United States)

    Root, J Jeffrey; Bentler, Kevin T; Nemeth, Nicole M; Gidlewski, Thomas; Spraker, Terry R; Franklin, Alan B

    2010-10-01

    To characterize the responses of raccoons to West Nile virus (WNV) infection, we subcutaneously exposed them to WNV. Moderately high viremia titers (≤ 10(4.6) plaque forming units [PFU]/mL of serum) were noted in select individuals; however, peak viremia titers were variable and viremia was detectable in some individuals as late as 10 days post-inoculation (DPI). In addition, fecal shedding was prolonged in some animals (e.g., between 6 and 13 DPI in one individual), with up to 10(5.0) PFU/fecal swab detected. West Nile virus was not detected in tissues collected on 10 or 16 DPI, and no histologic lesions attributable to WNV infection were observed. Overall, viremia profiles suggest that raccoons are unlikely to be important WNV amplifying hosts. However, this species may occasionally shed significant quantities of virus in feces. Considering their behavioral ecology, including repeated use of same-site latrines, high levels of fecal shedding could potentially lead to interspecies fecal-oral WNV transmission.

  11. Natural and experimental evidence of viscerotropic infection caused by Leishmania tropica from North Sinai, Egypt.

    Science.gov (United States)

    Doha, Said A; Shehata, Magdi G; Fahmy, Adel R; Samy, Abdallah M

    2014-08-01

    Cutaneous leishmaniasis (CL) is a neglected clinical form that is quite prevalent in Eastern North parts of the country in Sinai Peninsula. Leishmania tropica was identified by previous reports as the causative agent responsible for viscerotropic infections in-patients and experimental animals. Here, we reported the viscerotropic infections from naturally infected rodent Gerbillus pyramidum floweri collected from North-Sinai. Footpad and tail lesions, spleenomegaly, and malformed dark-colored spleen were the characteristic CL symptoms. The spleen of the rodent found positive to amastigote impression smear. ITS-1 DNA was sequenced and revealed 100% identity of the strain in the current study to the other L. tropica sequences identified from the patients with the suspected CL and inhabited the same study area. The current findings confirmed the susceptibility of gerbil to L. tropica, and raise the concerns for the role of rodents as accidental host suffering the infections. The susceptibility of wild and experimental rodents to the same L. tropica strain was also investigated; BALB/c and G. pyramidum were more susceptible to L. tropica (24.33 ± 4.37 and 25 ± 4.58 days post-infection, respectively). Similar viscerotropic pathologies were reported in experimental infection of only golden hamster (≈ 120 days post-infection), and G. p. floweri (≈ 160 days post-infection).

  12. Bovine mastitis caused by Listeria monocytogenes: characteristics of natural and experimental infections.

    Science.gov (United States)

    Bourry, A; Poutrel, B; Rocourt, J

    1995-08-01

    Experimental mastitis induced with a single intramammary injection of Listeria monocytogenes was compared with two naturally occurring cases. Four strains of L. monocytogenes, two of serotype 1/2a and two of serotype 4b were used for the experimental infections and two diametrically opposed quarters of four cows were inoculated with 300 cfu. Bacteriological examination and somatic cell counts of quarter foremilk samples were performed weekly for at least 6 months after challenge. All the inoculated quarters developed chronic subclinical mastitis with occasional clinical episodes. The results were similar to those observed in natural listeria mastitis. Four experimentally infected quarters were treated during lactation (gentamicin and cloxacillin) or at "drying-off" (cloxacillin), or at both times. Only one of four quarters was cured after treatment only at "drying-off". All experimental and naturally infected animals were slaughtered and bacteriological examination was performed on liver, spleen and supramammary, iliac and mesenteric lymph nodes. L. monocytogenes strains were isolated from the supramammary lymph nodes of two experimentally and two naturally infected cows and from an iliac lymph node from one of the naturally infected cows. The epidemiological data were supported by serotyping, lysotyping and DNA macro-restriction analysis. The experimental model of listeria mastitis mimics spontaneous cases and should be useful in further studies of listeria mastitis.

  13. Experimental Infection of the Skin in the Hamster Simulating Human Impetigo IV. Cellular Responses after Streptococcal and Staphylococcal Infections

    Science.gov (United States)

    Dajani, Adnan S.; Wannamaker, Lewis W.

    1972-01-01

    Various cellular responses to skin infections in an experimental animal model were explored. Total leukocyte counts varied after group A streptococcal infections, but a depression was commonly seen after M type 12 impetigo. Staphylococcus aureus infections resulted in moderate leukocytosis. A marked neutrophilia was universal with streptococcal or staphylococcal disease. A positive nitroblue tetrazolium (NBT) response appeared 24 hr after infection, reached a peak in 48 hr, and then declined. This occurred in the absence of extensive cellulitis or bacteremia. An increase in the percentage and absolute number of NBT-positive neutrophils occurred. M type 57 streptococcus produced a more strongly positive NBT test than did M type 12. Cell-free filtrates of a broth culture of M type 57 streptococcus produced NBT responses in hamsters comparable to the responses seen after injection of live organisms. These studies indicate the usefulness of this animal model to study various parameters of the NBT test. PMID:4117885

  14. Chlamydia trachomatis Infection in HIV-Infected Women: Need for Screening by a Sensitive and Specific Test

    Directory of Open Access Journals (Sweden)

    Sonali Bhattar

    2013-01-01

    Full Text Available Reproductive tract infection (RTIs/sexually transmitted infections (STIs are recognized as a major public health problem, particularly due to their relationship with HIV infection. Early detection and treatment of Chlamydia trachomatis infection (CTI among HIV-infected and HIV-uninfected women may impact heterosexual HIV transmission. A total of 120 participants were enrolled: 30 HIV seropositive women with symptoms of RTIs, 30 HIV seropositive women without symptoms of RTIs, 30 HIV seronegative women with symptoms of RTIs, and 30 HIV seronegative women without symptoms of RTIs. One endocervical swab was collected from all participants and CTI was detected by real-time PCR (COBAS TaqMan CT Test, v2.0. CTI was detected in 4 (6.67% HIV-infected women and in 1 (1.67% HIV-uninfected woman (OR 4.214; 95% CI 0.457–38.865. Vaginal discharge was present in almost half of HIV-infected and HIV-uninfected women; lower abdominal pain was present in 11 (18.3% of HIV-infected and in 9 (15% of HIV-uninfected women. This study showed that CTI is more prevalent among HIV-infected females as compared to HIV-uninfected females. As the use of real-time PCR is not feasible in most hospitals, efforts should be made to develop a simple, sensitive, and specific test to identify women with CTI for prevention of sequelae and HIV transmission.

  15. Towards the eradication of HPV infection through universal specific vaccination.

    Science.gov (United States)

    Crosignani, Piergiorgio; De Stefani, Antonella; Fara, Gaetano Maria; Isidori, Andrea M; Lenzi, Andrea; Liverani, Carlo Antonio; Lombardi, Alberto; Mennini, Francesco Saverio; Palu', Giorgio; Pecorelli, Sergio; Peracino, Andrea P; Signorelli, Carlo; Zuccotti, Gian Vincenzo

    2013-07-11

    The Human Papillomavirus (HPV) is generally recognized to be the direct cause of cervical cancer. The development of effective anti-HPV vaccines, included in the portfolio of recommended vaccinations for any given community, led to the consolidation in many countries of immunization programs to prevent HPV-related cervical cancers. In recent years, increasing evidence in epidemiology and molecular biology have supported the oncogenic role of HPV in the development of other neoplasm including condylomas and penile, anal, vulvar, vaginal, and oro-pharyngeal cancers. Men play a key role in the paradigm of HPV infection: both as patients and as part of the mechanisms of transmission. Data show they are affected almost as often as women. Moreover, no screening procedures for HPV-related disease prevention are applied in men, who fail to undergo routine medical testing by any medical specialist at all. They also do not benefit from government prevention strategies. A panel of experts convened to focus on scientific, medical, and economic studies, and on the achievements from health organizations' intervention programs on the matter. One of the goals was to discuss on the critical issues emerging from the ongoing global implementation of HPV vaccination. A second goal was to identify contributions which could overcome the barriers that impede or delay effective vaccination programs whose purpose is to eradicate the HPV infection both in women and men. The reviewed studies on the natural history of HPV infection and related diseases in women and men, the increasing experience of HPV vaccination in women, the analysis of clinical effectiveness vs economic efficacy of HPV vaccination, are even more supportive of the economic sustainability of vaccination programs both in women and men. Those achievements address increasing and needed attention to the issue of social equity in healthcare for both genders.

  16. Experimental infection of meadow voles (Microtus pennsylvanicus) with sheep scrapie

    Science.gov (United States)

    Carlson, CM; Schneider, Jay R.; Pedersen, Janice C.; Heisey, Dennis M.; Johnson, Christopher J.

    2015-01-01

    Meadow voles (Microtus pennsylvanicus) are permissive to chronic wasting disease (CWD) infection, but their susceptibility to other transmissible spongiform encephalopathies (TSEs) is poorly characterized. In this initial study, we intracerebrally challenged 6 meadow voles with 2 isolates of sheep scrapie. Three meadow voles acquired a TSE after the scrapie challenge and an extended incubation period. The glycoform profile of proteinase K-resistant prion protein (PrP(res)) in scrapie-sick voles remained similar to the sheep inocula, but differed from that of voles clinically affected by CWD. Vacuolization patterns and disease-associated prion protein (PrP(Sc)) deposition were generally similar in all scrapie-affected voles, except in the hippocampus, where PrP(Sc) staining varied markedly among the animals. Our results demonstrate that meadow voles can acquire a TSE after intracerebral scrapie challenge and that this species could therefore prove useful for characterizing scrapie isolates.

  17. Genetic Resistance to Scrapie Infection in Experimentally Challenged Goats

    Science.gov (United States)

    Lacroux, Caroline; Perrin-Chauvineau, Cécile; Corbière, Fabien; Aron, Naima; Aguilar-Calvo, Patricia; Torres, Juan Maria; Costes, Pierrette; Brémaud, Isabelle; Lugan, Séverine; Schelcher, François; Barillet, Francis

    2014-01-01

    In goats, several field studies have identified coding mutations of the gene encoding the prion protein (I/M142, N/D146, S/D146, R/Q211, and Q/K222) that are associated with a lower risk of developing classical scrapie. However, the data related to the levels of resistance to transmissible spongiform encephalopathies (TSEs) of these different PRNP gene mutations are still considered insufficient for developing large-scale genetic selection against scrapie in this species. In this study, we inoculated wild-type (WT) PRNP (I142R154R211Q222) goats and homozygous and/or heterozygous I/M142, R/H154, R/Q211, and Q/K222 goats with a goat natural scrapie isolate by either the oral or the intracerebral (i.c.) route. Our results indicate that the I/M142 PRNP polymorphism does not provide substantial resistance to scrapie infection following intracerebral or oral inoculation. They also demonstrate that H154, Q211, and K222 PRNP allele carriers are all resistant to scrapie infection following oral exposure. However, in comparison to WT animals, the H154 and Q211 allele carriers displayed only moderate increases in the incubation period following i.c. challenge. After i.c. challenge, heterozygous K222 and a small proportion of homozygous K222 goats also developed the disease, but with incubation periods that were 4 to 5 times longer than those in WT animals. These results support the contention that the K222 goat prion protein variant provides a strong but not absolutely protective effect against classical scrapie. PMID:24284317

  18. Evaluation of metaphylactic RNA interference to prevent equine herpesvirus type 1 infection in experimental herpesvirus myeloencephalopathy in horses.

    Science.gov (United States)

    Perkins, Gillian A; Van de Walle, Gerlinde R; Pusterla, Nicola; Erb, Hollis N; Osterrieder, Nikolaus

    2013-02-01

    To evaluate metaphylactic RNA interference to prevent equine herpesvirus type 1 (EHV-1) infection in experimental herpesvirus myeloencephalopathy in horses and to determine whether horses infected with a neuropathogenic strain of the virus that develop equine herpesvirus myeloencephalopathy (EHM) have differences in viremia. 13 seronegative horses. EHV-1 strain Ab4 was administered intranasally on day 0, and small interfering RNAs (siRNAs [EHV-1 specific siRNAs {n = 7} or an irrelevant siRNA {6}]) were administered intranasally 24 hours before and 12, 24, 36, and 48 hours after infection. Physical and neurologic examinations, nasal swab specimens, and blood samples were collected for virus isolation and quantitative PCR assay. Data from the study were combined with data from a previous study of 14 horses. No significant difference was detected in clinical variables, viremia, or detection of EHV-1 in nasal swab specimens of horses treated with the EHV-1 targeted siRNAs (sigB3-siOri2) versus controls. No significant differences in viremia were detected between horses that developed EHM and those that did not. Administration of siRNAs targeted against EHV-1 around the time of EHV-1 infection was not protective with this experimental design. Horses infected with the neuropathogenic EHV-1 strain Ab4 that developed EHM did not have a more pronounced viremia.

  19. Efficacy of domestic cooking inactivation of human hepatitis A virus in experimentally infected manila clams (Ruditapes philippinarum).

    Science.gov (United States)

    Pascoli, F; Pezzuto, A; Buratin, A; Piovesana, A; Fortin, A; Arcangeli, G; Toffan, A

    2016-10-01

    The aim of this work was to evaluate the efficacy of domestic cooking in inactivating Manila clams experimentally infected with human hepatitis A virus (HAV). Electronic temperature probes were positioned to measure the internal temperature of Manila clams during domestic cooking. Two batches were infected with 10(7) and 10(5) TCID50  ml(-1) of HAV. The infected whole-in-shell clams were divided into three replicates and cooked on a conventional stove both singularly and in group and removed from the pan at fixed intervals. Pools of three digestive glands were examined by virus isolation for three blind passages and cell culture supernatant tested with real-time PCR. Results showed that 2-min cooking by a traditional domestic method at a temperature close to 100°C, after the opening up of the valves of all the clams, can completely devitalize the HAV in high viral load-infected clams. This is the first study on inactivation of HAV in experimentally infected Manila clams subjected to domestic cooking. At present, labelling all lagoon products as 'requiring cooking before consumption' is highly recommended, but no specifications are given on how long and at what temperature they should be cooked. Considering the high commercial value of Manila clams, our results can provide both the producers and the consumer with useful indications on how to cook clams to prevent the risk of HAV foodborne illness. © 2016 The Society for Applied Microbiology.

  20. Trypanosoma cruzi-Trypanosoma rangeli co-infection ameliorates negative effects of single trypanosome infections in experimentally infected Rhodnius prolixus.

    Science.gov (United States)

    Peterson, Jennifer K; Graham, Andrea L; Elliott, Ryan J; Dobson, Andrew P; Triana Chávez, Omar

    2016-08-01

    Trypanosoma cruzi, causative agent of Chagas disease, co-infects its triatomine vector with its sister species Trypanosoma rangeli, which shares 60% of its antigens with T. cruzi. Additionally, T. rangeli has been observed to be pathogenic in some of its vector species. Although T. cruzi-T. rangeli co-infections are common, their effect on the vector has rarely been investigated. Therefore, we measured the fitness (survival and reproduction) of triatomine species Rhodnius prolixus infected with just T. cruzi, just T. rangeli, or both T. cruzi and T. rangeli. We found that survival (as estimated by survival probability and hazard ratios) was significantly different between treatments, with the T. cruzi treatment group having lower survival than the co-infected treatment. Reproduction and total fitness estimates in the T. cruzi and T. rangeli treatments were significantly lower than in the co-infected and control groups. The T. cruzi and T. rangeli treatment group fitness estimates were not significantly different from each other. Additionally, co-infected insects appeared to tolerate higher doses of parasites than insects with single-species infections. Our results suggest that T. cruzi-T. rangeli co-infection could ameliorate negative effects of single infections of either parasite on R. prolixus and potentially help it to tolerate higher parasite doses.

  1. Age-specificity of clinical dengue during primary and secondary infections.

    Directory of Open Access Journals (Sweden)

    Khoa T D Thai

    2011-06-01

    Full Text Available This study aims to estimate the age-specific risks of clinical dengue attack (i.e., the risk of symptomatic dengue among the total number of dengue virus (DENV infections during primary and secondary infections.We analyzed two pieces of epidemiological information in Binh Thuan province, southern Vietnam, i.e., age-specific seroprevalence and a community-wide longitudinal study of clinical dengue attack. The latter data set stratified febrile patients with DENV infection by age as well as infection parity. A simple modeling approach was employed to estimate the age-specific risks of clinical dengue attack during primary and secondary infections.Using the seroprevalence data, the force of infection was estimated to be 11.7% (95% confidence intervals (CI: 10.8-12.7 per year. Median age (and the 25-75 percentiles of dengue fever patients during primary and secondary infections were 12 (9-20 and 20 (14-31 years, respectively. The estimated age-specific risk of clinical dengue increases as a function of age for both primary and secondary infections; the estimated proportion of symptomatic patients among the total number of infected individuals was estimated to be <7% for those aged <10 years for both primary and secondary infections, but increased as patients become older, reaching to 8-11% by the age of 20 years.For both primary and secondary infections, higher age at DENV infection was shown to result in higher risk of clinical attack. Age as an important modulator of clinical dengue explains recent increase in dengue notifications in ageing countries in Southeast Asia, and moreover, poses a paradoxical problem of an increase in adult patients resulting from a decline in the force of infection, which may be caused by various factors including time-dependent variations in epidemiological, ecological and demographic dynamics.

  2. Histopathological study of experimental and natural infections by Trypanosoma cruzi in Didelphis marsupialis

    Directory of Open Access Journals (Sweden)

    João Carlos Araujo Carreira

    1996-10-01

    Full Text Available Didelphis marsupialis, the most important sylvatic reservoir of Trypanosoma cruzi, can also maintain in their anal scent glands the multiplicative forms only described in the intestinal tract of triatomine bugs. A study of 21 experimentally and 10 naturally infected opossums with T. cruzi was undertaken in order to establish the histopathological pattern under different conditions. Our results showed that the inflammation was predominantly lymphomacrophagic and more severe in the naturally infected animals but never as intense as those described in Chagas' disease or in other animal models. The parasitism in both groups was always mild with very scarce amastigote nests in the tissues. In the experimentally infected animals, the inflammation was directly related to the presence of amastigotes nests. Four 24 days-old animals, still in embryonic stage, showed multiple amastigotes nests and moderate inflammatory reactions, but even so they survived longer and presented less severe lesions than experimentally infected adult mice. Parasites were found in smooth, cardiac and/or predominantly striated muscles, as well as in nerve cells. Differing from the experimentally infected opossums parasitism in the naturally infected animals predominated in the heart, esophagus and stomach. Parasitism of the scent glands did not affect the histopathological pattern observed in extraglandular tissues.

  3. Genotyping of Trypanosoma cruzi DTUs and Trypanosoma rangeli genetic groups in experimentally infected Rhodnius prolixus by PCR-RFLP.

    Science.gov (United States)

    Sá, Amanda R N; Dias, Greicy B M; Kimoto, Karen Y; Steindel, Mário; Grisard, Edmundo C; Toledo, Max Jean O; Gomes, Mônica L

    2016-04-01

    The specific detection and genetic typing of trypanosomes that infect humans, mammalian reservoirs, and vectors is crucial for diagnosis and epidemiology. We utilized a PCR-RFLP assay that targeted subunit II of cytochrome oxidase and 24Sα-rDNA to simultaneously detect and discriminate six Trypanosoma cruzi discrete typing units (DTUs) and two genetic groups of Trypanosoma rangeli (KP1+/KP1-) in intestinal contents of experimentally infected Rhodnius prolixus. The PCR assays showed that in 23 of 29 (79.4%) mixed infections with the six T. cruzi DTUs and mixed infections with individual DTUs and/or groups KP1+ and KP1-, both parasites were successfully detected. In six mixed infections that involved TcIII, the TcI, TcII, TcV, and TcVI DTUs predominated to the detriment of TcIII, indicating the selection of genetic groups. Interactions between different genetic groups and vectors may lead to genetic selection over TcIII. The elimination of this DTU by the immune system of the vector appears unlikely because TcIII was present in other mixed infections (TcIII/TcIV and TcIII/KP1+). Both molecular markers used in this study were sensitive and specific, demonstrating their usefulness in a wide geographical area where distinct genotypes of these two species are sympatric. Although the cellular and molecular mechanisms that are involved in parasite-vector interactions are still poorly understood, our results indicate a dynamic selection toward specific T. cruzi DTUs in R. prolixus during mixed genotype infections. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. The specifities of the HPV-genital infections in males

    Directory of Open Access Journals (Sweden)

    Mihael Skerlev

    2010-08-01

    Full Text Available Anogenital infections caused by Human papillomavirus (HPV are the most frequently diagnosed sexually transmitted infections of viral origin and up to 150 HPV DNA types have been recognized so far. Anogenital warts (condylomata acuminata are the most common lesions presented in men, however, during the last decade the other HPV-associated exaggerated lesions such as condylomata plana, penile,scrotal, and anal intraepithelial neoplasias, as well as the penile, urine bladder and prostate cancer have been studied somewhat more extensively. The clinical variations might range from clinically invisible, asymptomatic lesions to the bizarre forms of giant condyloma of Buschke-Löwenstein type, including Bowenoid papulosis,Mb. Bowen, different kinds of eryhtroplasia both in men and women and a large spectrum of HPV-induced dermatovenereological entities in genital region including high-grade intraepithelial genital neoplasias, such as penile, anal, scrotal, vulvar, vaginal etc. (thus not only cervical, and, last but not least - the anogenital warts. A prophylactic vaccine that targets these types should thus substantially reduce the burden of HPV-associated clinical diseases. Ultimately, within the spectrum of therapeutic options for condylomata, no method is really superior to others; recurrences occurred in 30-70% of cases. We definitely need the HPV vaccination programme to eliminate one of the oldest and up to now unsolved problems of the mankind. Since HPV is transmitted by sexual intercourse, treatment of both partners is necessary in order to eliminate the virus from the population. Approaches to this include prophylactic vaccines such as quadrivalent HPV vaccine for both men and women

  5. Persistent immune responses in late infection and after treatment in experimental Schistosoma bovis infections in goats.

    Science.gov (United States)

    Sörén, K; Monrad, J; Johansen, M V; Lindberg, R

    2009-06-01

    This study explored host immune responses and their possible relationship to the anti-fecundity phenomenon in Schistosoma bovis-infected goats. The design comprised a primary infection with or without treatment at week (wk) 13, and with or without challenge at wk 36. Necropsy was performed at 36 or 52wk. Serum levels of anti-egg IgG, and anti-worm IgG and IgM, were measured by ELISA. In chronic infection, anti-worm antibodies stayed high, reflecting persisting worm burdens, whereas anti-egg IgG remained high despite minimized egg excretion. After treatment, anti-worm IgM and anti-egg IgG were minimized, but anti-worm IgG remained above the values of the uninfected controls. Histopathology showed lowered numbers of perioval granulomas in chronic infection and resolution of liver fibrosis with time, but intestinal lymphoplasmacytic perivasculitis and hepatic eosinophilic infiltrates were maintained at wk 52. Significant splenic plasmacytosis persisted after treatment. The results indicated that persistent immune responses, in chronically infected and in treated goats, may explain sustained worm fecundity depression at challenge infection.

  6. Gene Specific DNA Sensors for Diagnosis of Pathogenic Infections.

    Science.gov (United States)

    Datta, Manali; Desai, Dignya; Kumar, Ashok

    2017-06-01

    Gene specific DNA based sensors have potential applications for rapid and real time monitoring of hybridization signal with the target nucleic acid of pathogens. Different types of DNA based sensors and their applications have been studied for rapid and accurate detection of pathogens causing human diseases. These sensors are based on surface plasmon resonance, quantum-dots, molecular beacons, piezoelectric and electrochemical etc. Curbing epidemics at an early stage is one of the massive challenges in healthcare systems. Timely detection of the causative organism may provide a solution to restrain mortality caused by the disease. With the advent of interdisciplinary sciences, bioelectronics has emerged as an effective alternative for disease diagnostics. Gene specific DNA sensors present themselves as cost-effective, sensitive and specific platforms for detection of disease causing pathogens. The mini review explores different transducer based sensors and their potential in diagnosis of acute and chronic diseases.

  7. Natural and experimental oral infection of nonhuman primates by bovine spongiform encephalopathy agents.

    Science.gov (United States)

    Bons, N; Mestre-Frances, N; Belli, P; Cathala, F; Gajdusek, D C; Brown, P

    1999-03-30

    Experimental lemurs either were infected orally with the agent of bovine spongiform encephalopathy (BSE) or were maintained as uninfected control animals. Immunohistochemical examination for proteinase-resistant protein (prion protein or PrP) was performed on tissues from two infected but still asymptomatic lemurs, killed 5 months after infection, and from three uninfected control lemurs. Control tissues showed no staining, whereas PrP was detected in the infected animals in tonsil, gastrointestinal tract and associated lymphatic tissues, and spleen. In addition, PrP was detected in ventral and dorsal roots of the cervical spinal cord, and within the spinal cord PrP could be traced in nerve tracts as far as the cerebral cortex. Similar patterns of PrP immunoreactivity were seen in two symptomatic and 18 apparently healthy lemurs in three different French primate centers, all of which had been fed diets supplemented with a beef protein product manufactured by a British company that has since ceased to include beef in its veterinary nutritional products. This study of BSE-infected lemurs early in their incubation period extends previous pathogenesis studies of the distribution of infectivity and PrP in natural and experimental scrapie. The similarity of neuropathology and PrP immunostaining patterns in experimentally infected animals to those observed in both symptomatic and asymptomatic animals in primate centers suggests that BSE contamination of zoo animals may have been more widespread than is generally appreciated.

  8. Cysticercosis in experimentally and naturally infected pigs: parasitological and immunological diagnosis

    Directory of Open Access Journals (Sweden)

    Márcia R.M. da Silva

    2012-04-01

    Full Text Available Our objective was to evaluate the diagnosis of swine cysticercosis by examining "ante mortem" (inspection of the tongue, "post mortem" (inspection and detailed necropsy and ELISA for research in serum of antibodies (Ab-ELISA and antigens (Ag-ELISA. Seven (7 pigs were experimentally infected orally with eggs of Taenia solium and another 10 were naturally infected. In the pigs experimentally infected, inspection of the tongue was negative in all animals, in the routine inspection detailed necropsy and cysticercis were identified in all of them. In pigs with heavy natural infection, inspection of the tongue identified cysticerci in two (20%, while at inspection with necropsy the parasites were identified in large quantities in all animals. In ELISA for antibody search (Ab-ELISA TS-14 recombinant protein was used, and in search for antigen (Ag-ELISA a monoclonal antibody against this protein. In animals experimentally infected, blood was collected weekly for 140 days. The Ab-ELISA identified an increase in titers of antibody to cysticerci 21 days after infection, and at the end of the experimental period six animals (86% were positive to the test. The search for circulating antigens (Ag-ELISA was positive in two pigs 28 to 91 days after infection. All naturally infected pigs were positive for Ag-ELISA and Ab-ELISA. The search for antibodies and antigens by ELISA in serum from 30 pigs of a local farm and without history of cysticercosis was negative. Thus, the use of TS-14 antigen in ELISA test (Ab-ELISA can be useful for the diagnosis of cysticercosis in pigs with low infection.

  9. Temperature alters host genotype-specific susceptibility to chytrid infection

    NARCIS (Netherlands)

    Gsell, A.S.; De Senerpont Domis, L.N.; Van Donk, E.; Ibelings, B.W.

    2013-01-01

    The cost of parasitism often depends on environmental conditions and host identity. Therefore, variation in the biotic and abiotic environment can have repercussions on both, species-level host-parasite interaction patterns but also on host genotype-specific susceptibility to disease. We exposed

  10. Immunopathological assessments of human Blastocystis spp. in experimentally infected immunocompetent and immunosuppresed mice.

    Science.gov (United States)

    Abdel-Hafeez, Ekhlas H; Ahmad, Azza K; Abdelgelil, Noha H; Abdellatif, Manal Z M; Kamal, Amany M; Hassanin, Kamel M A; Abdel-Razik, Abdel-Razik H; Abdel-Raheem, Ehab M

    2016-05-01

    Blastocystis spp., one of the most common parasites colonizing the human intestine, is an extracellular, luminal protozoan with controversial pathogenesis. The host's immune response against Blastocystis spp. infection has also not been defined yet. Therefore, this research aimed to assess the potential pathogenicity of this parasite and its ability to modulate the immune response in experimental infected immunocompetent and immunosuppresed mice. These results demonstrated that the infected immunosuppressed mice were more affected than infected immunocompetent mice. Histopathological examination of the small intestine in the infected immunosuppressed mice showed that Blastocystis spp. infiltrated all the layers. Moreover, the epithelia showed exfoliation and inflammatory cell infiltration in submucosa compared to that of the infected immunocompetent mice. As well, examination of the large intestine of the infected immunosuppressed group showed severe goblet cell hyperplasia. Blastocystis spp. infiltrated all the large intestine layers compared to that of the infected immunocompetent group. Furthermore, there was a significant upregulation of the expression of proinflammatory cytokines: interleukin 12 (IL-12) and tumor necrosis factor alpha (TNF-α) in the infected immunosuppressed mice compared to that of the infected immunocompetent ones (p ≤ 0.004 and p ≤ 0.002, respectively). However, the expression of anti-inflammatory cytokines (IL-4 and IL-10) was significantly downregulated in the infected immunosuppressed group compared to that of the infected immunocompetent group one at 10 days postinfection (p ≤ 0.002 and p ≤ 0.001, respectively). The results of this study revealed that Blastocystis spp. affected the production of pro- and anti-inflammatory cytokines in both groups of mice compared to healthy normal (naive) group. Additionally, these data showed that there was a significant upregulation (p ≤ 0.005) of the locally

  11. Praziquantel treatment decreases Schistosoma mansoni genetic diversity in experimental infections.

    Directory of Open Access Journals (Sweden)

    Regina Coeli

    Full Text Available BACKGROUND: Schistosomiasis has a considerable impact on public health in many tropical and subtropical areas. In the new world, schistosomiasis is caused by the digenetic trematode Schistosoma mansoni. Chemotherapy is the main measure for controlling schistosomiasis, and the current drug of choice for treatment is praziquantel (PZQ. Although PZQ is efficient and safe, its repetitive large-scale use in endemic areas may lead to the selection of resistant strains. Isolates less susceptible to PZQ have been found in the field and selected for in the laboratory. The impact of selecting strains with a decreased susceptibility phenotype on disease dynamics and parasite population genetics is not fully understood. This study addresses the impact of PZQ pressure on the genetics of a laboratory population by analyzing frequency variations of polymorphic genetic markers. METHODOLOGY: Infected mice were treated with increasing PZQ doses until the highest dose of 3 × 300 mg/Kg was reached. The effect of PZQ treatment on the parasite population was assessed using five polymorphic microsatellite markers. Parasitological and genetic data were compared with those of the untreated control. After six parasite generations submitted to treatment, it was possible to obtain a S. mansoni population with decreased susceptibility to PZQ. In our experiments we also observed that female worms were more susceptible to PZQ than male worms. CONCLUSIONS: The selective pressure exerted by PZQ led to decreased genetic variability in S. mansoni and increased endogamy. The understanding of how S. mansoni populations respond to successive drug pressure has important implications on the appearance and maintenance of a PZQ resistance phenotype in endemic regions.

  12. Comparison of specificities of serum antibody responses of horses to clinical infections caused by Streptococcus equi or zooepidemicus.

    Science.gov (United States)

    Velineni, Sridhar; DeNegri, Rafaela; Artiushin, Sergey C; Timoney, John F

    2015-11-18

    Streptococcus zooepidemicus (Sz) and its clonal derivative Streptococcus equi (Se) share greater than 96% DNA identity and elicit immune responses to many shared proteins. Identification of proteins uniquely targeted by the immune response to each infection would have diagnostic value. The aim of the study was to compare serum antibody responses of horses infected by Se or Sz. Antibody levels were measured to panels of recombinant proteins of Sz and Se in sera of horses and ponies before and after experimental and naturally occurring invasive infections by these organisms. Antibody responses to an Se extract vaccine were also measured. Sera diluted 1:200 were assayed in triplicate using optimum concentrations of 9 and 14 immunoreactive proteins of Se and Sz, respectively. Bound IgG was detected using HRP-Protein G conjugate. Antibodies specific for SeM-N2, IdeE2, Se42.0 and Se75.3 (SEQ2190) were elicited by Se but not by Sz infection. Commercial Se extract vaccine did not elicit responses to IdeE2 or Se75.3. Sz infections resulted in significant (pScpC, SzP, MAP and streptokinase an indication these proteins are expressed during opportunistic invasions of the respiratory tract. FSR and HylC specific responses were unique to infections by Sz. The data indicate antibodies to IdeE2, Se75.3 and SeM-N2 may be used to distinguish infection by Se from that caused by the closely related Sz. Se infection, but not vaccination with Se extract elicits antibody to IdeE2 and Se75.3. Copyright © 2015. Published by Elsevier B.V.

  13. Natural and experimental West Nile virus infection in five raptor species.

    Science.gov (United States)

    Nemeth, Nicole; Gould, Daniel; Bowen, Richard; Komar, Nicholas

    2006-01-01

    We studied the effects of natural and/or experimental infections of West Nile virus (WNV) in five raptor species from July 2002 to March 2004, including American kestrels (Falco sparverius), golden eagles (Aquila chrysaetos), red-tailed hawks (Buteo jamaicensis), barn owls (Tyto alba), and great horned owls (Bubo virginianus). Birds were infected per mosquito bite, per os, or percutaneously by needle. Many experimentally infected birds developed mosquito-infectious levels of viremia (>10(5) WNV plaque forming units per ml serum) within 5 days postinoculation (DPI), and/ or shed virus per os or per cloaca. Infection of organs 15-27 days postinoculation was infrequently detected by virus isolation from spleen, kidney, skin, heart, brain, and eye in convalescent birds. Histopathologic findings varied among species and by method of infection. The most common histopathologic lesions were subacute myocarditis and encephalitis. Several birds had a more acute, severe disease condition represented by arteritis and associated with tissue degeneration and necrosis. This study demonstrates that raptor species vary in their response to WNV infection and that several modes of exposure (e.g., oral) may result in infection. Wildlife managers should recognize that, although many WNV infections are sublethal to raptors, subacute lesions could potentially reduce viability of populations. We recommend that raptor handlers consider raptors as a potential source of WNV contamination due to oral and cloacal shedding.

  14. Isolation of Trichophyton mentogrophytes var mentogrophytes from naturally infected laboratory albino rats: experimental infection and treatment in rabbits

    Directory of Open Access Journals (Sweden)

    N. A. Issa

    2009-01-01

    Full Text Available The present study demonstrated for the first time the occurrence of dermatophytosis in naturally infected rats and from asymptomatic and from breeding boxes of white rats kept in animal housing of college of Veterinary Medicine, University of Dohuk, Iraq. The prevalence rate of infection was (28%, clinically infected rats characterized by appearance of scaly ovoid type lesions with crusty edge and patch of hair loss mostly seen on the back, neck and face of the infected rats, itching was reported in some rats. Only one species of the trichophyton, T. mentogrophytes var mentogrophytes was isolated with growth rate (85.71% of samples collected from clinically infected rats, and (28.57% from asymptomatic and from breeding cages, the growth was observed within the 21 days at 25ºC on Sabouraud's Dextrose Agar. Lacto phenol cotton blue staining slides of T. mentogrophytes var mentogrophytes revealed both microconidia and macroconidia. Microconidia found in numerous numbers often in dense cluster which were hyaline, smooth walled and predominantly spherical to sub spherical in shape, varying numbers of chlamydoconidia. Spiral hyphae and smooth, thin walled clavate shaped multicelled macroconidia were also present. The study also dealt with experimental infection in rabbits with T. mentogrophytes var mentogrophytes and treated by two drugs, natural herbal preparation of acidic pomegranate (Punica granatum fruit and synthetic nystatine ointment. The complete recovery of lesions was recorded after 14 days and 21 days of topical application of a pomegranate and nystatine ointment for 5 successive days respectively.

  15. Use of Tc-rCRP as a target for lytic antibody titration after experimental Trypanosoma cruzi infection.

    Science.gov (United States)

    Marques, Tatiane; Silva, Gustavo Caetano; Henrique Paiva, Priscila Moraes; Nascentes, Gabriel Antônio Nogueira; Ramirez, Luis Eduardo; Norris, Karen; Meira, Wendell Sérgio Ferreira

    2018-01-01

    Experimental Chagas disease has been used as a model to identify several host/parasite interaction factors involved in immune responses to Trypanosoma cruzi infection. One of the factors inherent to this parasite is the complement regulatory protein (Tc-CRP), a major epitope that induces production of lytic antibodies during T. cruzi infections. Previous studies have evaluated the function of Tc-CRP as an antigenic marker via ELISAs, which demonstrated high sensitivity and specificity when compared to other methods. Therefore, this study aimed to assess and compare the levels of lytic antibodies induced by this protein following experimental infection using different T. cruzi strains. Our results demonstrated that infections induced by strains isolated from vectors resulted in subpatent parasitaemia and low reactivity, as assessed by Tc-rCRP ELISAs. On the other hand, mice inoculated with T. cruzi strains isolated from patients developed patent parasitaemia, and presented elevated lytic antibodies titres, as measured by Tc-rCRP ELISA. In addition, comparison between different mouse lineages demonstrated that Balb/c mice were more reactive than C57BL/6 mice in almost all types of infections, except those infected by the AQ-4 strain. Parasites from the Hel strain generated the greatest lytic antibody response in all evaluated models. Therefore, application of sensitive techniques for monitoring immune responses would enable us to establish growth curves for lytic antibodies during the course of the infection, and allow us to discriminate between T. cruzi strains that originate from different hosts. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Experimental Hendra virus infection of dogs: virus replication, shedding and potential for transmission.

    Science.gov (United States)

    Middleton, D J; Riddell, S; Klein, R; Arkinstall, R; Haining, J; Frazer, L; Mottley, C; Evans, R; Johnson, D; Pallister, J

    2017-01-01

    Characterisation of experimental Hendra virus (HeV) infection in dogs and assessment of associated transmission risk. Beagle dogs were exposed oronasally to Hendra virus/Australia/Horse/2008/Redlands or to blood collected from HeV-infected ferrets. Ferrets were exposed to oral fluids collected from dogs after canine exposure to HeV. Observations made and samples tested post-exposure were used to assess the clinical course and replication sites of HeV in dogs, the infectivity for ferrets of canine oral fluids and features of HeV infection in dogs following contact with infective blood. Dogs were reliably infected with HeV and were generally asymptomatic. HeV was re-isolated from the oral cavity and virus clearance was associated with development of virus neutralising antibody. Major sites of HeV replication in dogs were the tonsils, lower respiratory tract and associated lymph nodes. Virus replication was documented in canine kidney and spleen, confirming a viraemic phase for canine HeV infection and suggesting that urine may be a source of infectious virus. Infection was transmitted to ferrets via canine oral secretions, with copy numbers for the HeV N gene in canine oral swabs comparable to those reported for nasal swabs of experimentally infected horses. HeV is not highly pathogenic for dogs, but their oral secretions pose a potential transmission risk to people. The time-window for transmission risk is circumscribed and corresponds to the period of acute infection before establishment of an adaptive immune response. The likelihood of central nervous system involvement in canine HeV infection is unclear, as is any long-term consequence. © 2017 Australian Veterinary Association.

  17. Hematologic profile of hematophagous Desmodus rotundus bats before and after experimental infection with rabies virus

    Directory of Open Access Journals (Sweden)

    Marilene Fernandes de Almeida

    2014-06-01

    Full Text Available Introduction Hematophagous Desmodus rotundus bats play an important role in the rabies lifecycle. This study describes the hematological profile of these bats before and after experimental infection with rabies virus. Methods Cells counts were performed in a Neubauer chamber. Results The average values of erythrocytes and leucocytes counts in blood before experimental infections were 9.97 × 106mm3 and 4.80 × 103mm3, respectively. Neutrophils represented 69.9% of white blood cells and the lymphocytes represented 26.9%. Following the experimental infections, the average numbers of erythrocytes and leucocytes was 9.43 × 106mm3 and 3.98 × 103mm3, respectively. Neutrophils represented 40% of white blood cells and the lymphocytes represented 59%. Conclusions The hematological profile given in this study can serve as reference values for D. rotundus bats.

  18. Experimental infection with Escherichia coli 0149 : F4ac in weaned piglets

    DEFF Research Database (Denmark)

    Jensen, Gerda M.; Frydendahl, Kai; Svendsen, Ove

    2006-01-01

    The outcome of experimental intestinal infections with enterotoxigenic Escherichia coli (ETEC) is dependent on several factors. An important factor is adhesion of the challenge strain to the intestinal mucosa. The test for susceptibility towards ETEC adhesion has so far been made by an intestinal...... adhesion test made after slaughter of piglets. However, in an experimental infection study with the purpose to obtain diarrhoeic piglets, it would be an advantage to test for susceptibility prior to experimentation. The Mucin 4 gene on porcine chromosome 13 has been proposed as a candidate gene......-gastric intubated with 10(9) CFU of ETEC O149:F4ac and 23 age-matched piglets, both susceptible and resistant, were used as non-infected controls. Of susceptible piglets, challenged with ETEC 0149:F4ac, 74% had ETEC O149:F4ac-associated diarrhoea first day after first challenge, which were significantly higher...

  19. Age-specificity of clinical dengue during primary and secondary infections

    NARCIS (Netherlands)

    Thai, Khoa T. D.; Nishiura, Hiroshi; Hoang, Phuong Lan; Tran, Nga Thanh Thi; Phan, Giao Trong; Le, Hung Quoc; Tran, Binh Quang; Nguyen, Nam Van; de Vries, Peter J.

    2011-01-01

    This study aims to estimate the age-specific risks of clinical dengue attack (i.e., the risk of symptomatic dengue among the total number of dengue virus (DENV) infections) during primary and secondary infections. We analyzed two pieces of epidemiological information in Binh Thuan province, southern

  20. Specific serum antibody responses following a Toxoplasma gondii and Trichinella spiralis co-infection in swine

    NARCIS (Netherlands)

    Bokken, G.C.A.M.|info:eu-repo/dai/nl/304838578; van Eerden, E.; Opsteegh, M.|info:eu-repo/dai/nl/31149305X; Augustijn, M.|info:eu-repo/dai/nl/304836680; Graat, E.A.M.; Franssen, F.F.J.; Gorlich, K.; Buschtöns, S.; Tenter, A.M.; van der Giessen, J.W.B.; Bergwerff, A.A.|info:eu-repo/dai/nl/125023553; van Knapen, F.|info:eu-repo/dai/nl/070114749

    2012-01-01

    The aim of this study was to examine the dynamics of parasite specific antibody development in Trichinella spiralis and Toxoplasma gondii co-infections in pigs and to compare these with antibody dynamics in T. spiralis and T. gondii single infections. In this experiment, fifty-four pigs were divided

  1. Specific serum antibody responses following a Toxoplasma gondii and Trichinella spiralis co-infection in swine

    NARCIS (Netherlands)

    Bokken, G.; Eerden, van E.; Opsteegh, M.; Augustijn, M.; Graat, E.A.M.; Franssen, F.; Görlich, K.; Buschtöns, S.; Tenter, A.M.; Giessen, van der J.W.B.; Bergwerff, A.A.; Knapen, van F.

    2012-01-01

    The aim of this study was to examine the dynamics of parasite specific antibody development in Trichinella spiralis and Toxoplasma gondii co-infections in pigs and to compare these with antibody dynamics in T. spiralis and T. gondii single infections. In this experiment, fiftyfour pigs were divided

  2. Factors associated with type-specific persistence of high-risk human papillomavirus infection

    DEFF Research Database (Denmark)

    Stensen, Signe; Kjær, Susanne K; Jensen, Signe Marie

    2016-01-01

    Persistent genital infection with high-risk (HR) human papillomavirus (HPV) is a prerequisite for cervical cancer development. The aim of this study was to identify factors associated with type-specific persistence of HR HPV infections. From a population-based cohort of 40,399 women participating...

  3. Eimeria stiedai: Metabolism of lipids, proteins and glucose in experimentally infected rabbits, Oryctolagus cuniculus

    OpenAIRE

    Freitas, Fagner L. C.; Yamamoto, Beatriz L.; Freitas, Wagner L. C; Almeida, Katyane S; Machado, Rosangela Z. [UNESP; Machado, Célio R. [UNESP

    2010-01-01

    Rabbits were experimentally infected with sporulated Eimeria stiedai oocysts. A total of 50 white adult rabbits, New Zealand race, were distributed into two groups: Group A was infected with 1x10 4 sporulated Eimeria stiedai oocysts, while group B was inoculated with distilled water as a control. The animals generally displayed increased levels of total protein, globulin, total cholesterol, LDL-c and triacylglycerols; however, total levels of liver lipids and HDL-c decreased, and plasma gluco...

  4. Experimental Infection of Rabbits with Rabbit and Genotypes 1 and 4 Hepatitis E Viruses

    OpenAIRE

    Ma, H. X.; Zheng, L.; Liu, Y. B.; Zhao, C. Y.; Harrison, T. J.; Ma, Y. Y.; Sun, S. H.; Zhang, J. G.; Wang, Y. C.

    2010-01-01

    BACKGROUND: A recent study provided evidence that farmed rabbits in China harbor a novel hepatitis E virus (HEV) genotype. Although the rabbit HEV isolate had 77-79% nucleotide identity to the mammalian HEV genotypes 1 to 4, their genomic organization is very similar. Since rabbits are used widely experimentally, including as models of infection, we investigated whether they constitute an appropriate animal model for human HEV infection. METHODS: Forty-two SPF rabbits were divided randomly in...

  5. Cranberry juice and combinations of its organic acids are effective against experimental urinary tract infection

    DEFF Research Database (Denmark)

    Jensen, Heidi Dorthe; Struve, Carsten; Christensen, Søren Brøgger

    2017-01-01

    The antibacterial effect of cranberry juice and the organic acids therein on infection by uro28 pathogenic Escherichia coli was studied in an experimental mouse model of urinary tract infection (UTI). Reduced bacterial counts were found in the bladder (P ... juice. Commercially available cranberry juice cocktail also significantly reduced (P juice (P juice, were tested...... in combination and individually. The four organic acids also decreased bacterial levels in the bladder when administered together (P plus citric acid (P plus quinic acid (P

  6. Highly (H5N1 and low (H7N2 pathogenic avian influenza virus infection in falcons via nasochoanal route and ingestion of experimentally infected prey.

    Directory of Open Access Journals (Sweden)

    Kateri Bertran

    Full Text Available An experimental infection with highly pathogenic avian influenza (HPAI and low pathogenic avian influenza (LPAI viruses was carried out on falcons in order to examine the effects of these viruses in terms of pathogenesis, viral distribution in tissues and viral shedding. The distribution pattern of influenza virus receptors was also assessed. Captive-reared gyr-saker (Falco rusticolus x Falco cherrug hybrid falcons were challenged with a HPAI H5N1 virus (A/Great crested grebe/Basque Country/06.03249/2006 or a LPAI H7N2 virus (A/Anas plathyrhynchos/Spain/1877/2009, both via the nasochoanal route and by ingestion of previously infected specific pathogen free chicks. Infected falcons exhibited similar infection dynamics despite the different routes of exposure, demonstrating the effectiveness of in vivo feeding route. H5N1 infected falcons died, or were euthanized, between 5-7 days post-infection (dpi after showing acute severe neurological signs. Presence of viral antigen in several tissues was confirmed by immunohistochemistry and real time RT-PCR (RRT-PCR, which were generally associated with significant microscopical lesions, mostly in the brain. Neither clinical signs, nor histopathological findings were observed in any of the H7N2 LPAI infected falcons, although all of them had seroconverted by 11 dpi. Avian receptors were strongly present in the upper respiratory tract of the falcons, in accordance with the consistent oral viral shedding detected by RRT-PCR in both H5N1 HPAI and H7N2 LPAI infected falcons. The present study demonstrates that gyr-saker hybrid falcons are highly susceptible to H5N1 HPAI virus infection, as previously observed, and that they may play a major role in the spreading of both HPAI and LPAI viruses. For the first time in raptors, natural infection by feeding on infected prey was successfully reproduced. The use of avian prey species in falconry husbandry and wildlife rehabilitation facilities could put valuable birds

  7. Experimental infection of dogs with Leishmania and saliva as a model to study Canine Visceral Leishmaniasis.

    Directory of Open Access Journals (Sweden)

    Dirceu Joaquim Costa

    Full Text Available BACKGROUND: Canine Visceral Leishmaniasis (CVL is a zoonotic disease caused by Leishmania infantum, transmitted by the bite of Lutzomyia longipalpis sand flies. Dogs are the main domestic reservoir of the parasite. The establishment of an experimental model that partially reproduces natural infection in dogs is very important to test vaccine candidates, mainly regarding those that use salivary proteins from the vector and new therapeutical approaches. METHODOLOGY/PRINCIPAL FINDINGS: In this report, we describe an experimental infection in dogs, using intradermal injection of Leishmania infantum plus salivary gland homogenate (SGH of Lutzomyia longipalpis. Thirty-five dogs were infected with 1×10(7 parasites combined with five pairs of Lutzomyia longipalpis salivary glands and followed for 450 days after infection and clinical, immunological and parasitological parameters were evaluated. Two hundred and ten days after infection we observed that 31,4% of dogs did not display detectable levels of anti-Leishmania antibodies but all presented different numbers of parasites in the lymph nodes. Animals with a positive xenodiagnosis had at least 3,35×10(5 parasites in their lymph nodes. An increase of IFN-γ and IL-10 levels was detected during infection. Twenty two percent of dogs developed symptoms of CVL during infection. CONCLUSION: The infection model described here shows some degree of similarity when compared with naturally infected dogs opening new perspectives for the study of CVL using an experimental model that employs the combination of parasites and sand fly saliva both present during natural transmission.

  8. RNA-directed gene editing specifically eradicates latent and prevents new HIV-1 infection

    National Research Council Canada - National Science Library

    Wenhui Hu; Rafal Kaminski; Fan Yang; Yonggang Zhang; Laura Cosentino; Fang Li; Biao Luo; David Alvarez-Carbonell; Yoelvis Garcia-Mesa; Jonathan Karn; Xianming Mo; Kamel Khalili

    2014-01-01

    .... We identified highly specific targets within the HIV-1 LTR U3 region that were efficiently edited by Cas9/gRNA, inactivating viral gene expression and replication in latently infected microglial...

  9. Selective culling of high avidity antigen-specific CD4+ T cells after virulent Salmonella infection

    Science.gov (United States)

    Ertelt, James M; Johanns, Tanner M; Mysz, Margaret A; Nanton, Minelva R; Rowe, Jared H; Aguilera, Marijo N; Way, Sing Sing

    2011-01-01

    Typhoid fever is a persistent infection caused by host-adapted Salmonella strains adept at circumventing immune-mediated host defences. Given the importance of T cells in protection, the culling of activated CD4+ T cells after primary infection has been proposed as a potential immune evasion strategy used by this pathogen. We demonstrate that the purging of activated antigen-specific CD4+ T cells after virulent Salmonella infection requires SPI-2 encoded virulence determinants, and is not restricted only to cells with specificity to Salmonella-expressed antigens, but extends to CD4+ T cells primed to expand by co-infection with recombinant Listeria monocytogenes. Unexpectedly, however, the loss of activated CD4+ T cells during Salmonella infection demonstrated using a monoclonal population of adoptively transferred CD4+ T cells was not reproduced among the endogenous repertoire of antigen-specific CD4+ T cells identified with MHC class II tetramer. Analysis of T-cell receptor variable segment usage revealed the selective loss and reciprocal enrichment of defined CD4+ T-cell subsets after Salmonella co-infection that is associated with the purging of antigen-specific cells with the highest intensity of tetramer staining. Hence, virulent Salmonella triggers the selective culling of high avidity activated CD4+ T-cell subsets, which re-shapes the repertoire of antigen-specific T cells that persist later after infection. PMID:22044420

  10. Efficacy of different instrumentation techniques on reducing Enterococcus faecalis infection in experimentally infected root canals

    Directory of Open Access Journals (Sweden)

    Ebru Özsezer Demiryürek

    2014-03-01

    Conclusion: This study indicates that instruments with a greater taper play an important role in maximizing the effectiveness of mechanical preparation. However, since using mechanical instrumentation alone is insufficient to completely eliminate root canal infection, the use of complementary antibacterial compounds is necessary.

  11. Persistence of experimental Rocio virus infection in the golden hamster (Mesocricetus auratus

    Directory of Open Access Journals (Sweden)

    Daniele Freitas Henriques

    2012-08-01

    Full Text Available Rocio virus (ROCV is an encephalitic flavivirus endemic to Brazil. Experimental flavivirus infections have previously demonstrated a persistent infection and, in this study, we investigated the persistence of ROCV infection in golden hamsters (Mesocricetus auratus. The hamsters were infected intraperitoneally with 9.8 LD50/0.02 mL of ROCV and later anaesthetised and sacrificed at various time points over a 120-day period to collect of blood, urine and organ samples. The viral titres were quantified by real-time-polymerase chain reaction (qRT-PCR. The specimens were used to infect Vero cells and ROCV antigens in the cells were detected by immunefluorescence assay. The levels of antibodies were determined by the haemagglutination inhibition technique. A histopathological examination was performed on the tissues by staining with haematoxylin-eosin and detecting viral antigens by immunohistochemistry (IHC. ROCV induced a strong immune response and was pathogenic in hamsters through neuroinvasion. ROCV was recovered from Vero cells exposed to samples from the viscera, brain, blood, serum and urine and was detected by qRT-PCR in the brain, liver and blood for three months after infection. ROCV induced histopathological changes and the expression of viral antigens, which were detected by IHC in the liver, kidney, lung and brain up to four months after infection. These findings show that ROCV is pathogenic to golden hamsters and has the capacity to cause persistent infection in animals after intraperitoneal infection.

  12. Development of an experimental model of infected bone void in the ulna of rabbits

    Science.gov (United States)

    Lemos Azi, Matheus; Kfuri Junior, Mauricio; Martinez, Roberto; Salata, Luis Antonio; Paccola, Cleber Antonio Jansen

    2012-01-01

    Objective Develop a model that allowed the study of bone regeneration in infection conditions. Method A 15 mm defect was surgically created in the rabbit ulna and inoculated with 5x108 colony-forming units (CFU) of S. aureus. Surgical debridement was performed two weeks after and systemic gentamicin was administered for four weeks. Animals were followed up to 12 weeks to evaluate infection control and bone regeneration. Result Bone regeneration was inferior to 25% of the defect in radiological and histological analysis. Conclusion Infected bone defect of 15 mm in the rabbit ulna was unable to achieve full regeneration without further treatment. Level of Evidence V, Experimental Study. PMID:24453593

  13. Comparison of detection methods for Toxoplasma gondii in naturally and experimentally infected swine.

    Science.gov (United States)

    Hill, Dolores E; Chirukandoth, Sreekumar; Dubey, J P; Lunney, Joan K; Gamble, H Ray

    2006-10-10

    Results from recent serological surveys and epidemiological studies show that pigs raised in a variety of management systems can be carriers of the tissue cyst stage of Toxoplasma gondi. This parasite can be transmitted to humans through the consumption of improperly prepared pork, making detection and removal of infected swine carcasses from the food chain an important food safety issue. Several methods are available for detection of T. gondii infected swine, including serological assays, polymerase chain reaction, and animal bioassays. The aim of the present study was to compare the detection sensitivities of six of these commonly used methods for detection of T. gondii infection in tissues from naturally and experimentally infected pigs. The results indicate that a serum-based ELISA is the most sensitive method, of those tested, for detection of T. gondii infected swine.

  14. Natural and experimental infection of Caenorhabditis nematodes by novel viruses related to nodaviruses.

    Directory of Open Access Journals (Sweden)

    Marie-Anne Félix

    2011-01-01

    Full Text Available An ideal model system to study antiviral immunity and host-pathogen co-evolution would combine a genetically tractable small animal with a virus capable of naturally infecting the host organism. The use of C. elegans as a model to define host-viral interactions has been limited by the lack of viruses known to infect nematodes. From wild isolates of C. elegans and C. briggsae with unusual morphological phenotypes in intestinal cells, we identified two novel RNA viruses distantly related to known nodaviruses, one infecting specifically C. elegans (Orsay virus, the other C. briggsae (Santeuil virus. Bleaching of embryos cured infected cultures demonstrating that the viruses are neither stably integrated in the host genome nor transmitted vertically. 0.2 µm filtrates of the infected cultures could infect cured animals. Infected animals continuously maintained viral infection for 6 mo (∼50 generations, demonstrating that natural cycles of horizontal virus transmission were faithfully recapitulated in laboratory culture. In addition to infecting the natural C. elegans isolate, Orsay virus readily infected laboratory C. elegans mutants defective in RNAi and yielded higher levels of viral RNA and infection symptoms as compared to infection of the corresponding wild-type N2 strain. These results demonstrated a clear role for RNAi in the defense against this virus. Furthermore, different wild C. elegans isolates displayed differential susceptibility to infection by Orsay virus, thereby affording genetic approaches to defining antiviral loci. This discovery establishes a bona fide viral infection system to explore the natural ecology of nematodes, host-pathogen co-evolution, the evolution of small RNA responses, and innate antiviral mechanisms.

  15. Natural and experimental infection of Caenorhabditis nematodes by novel viruses related to nodaviruses.

    Science.gov (United States)

    Félix, Marie-Anne; Ashe, Alyson; Piffaretti, Joséphine; Wu, Guang; Nuez, Isabelle; Bélicard, Tony; Jiang, Yanfang; Zhao, Guoyan; Franz, Carl J; Goldstein, Leonard D; Sanroman, Mabel; Miska, Eric A; Wang, David

    2011-01-25

    An ideal model system to study antiviral immunity and host-pathogen co-evolution would combine a genetically tractable small animal with a virus capable of naturally infecting the host organism. The use of C. elegans as a model to define host-viral interactions has been limited by the lack of viruses known to infect nematodes. From wild isolates of C. elegans and C. briggsae with unusual morphological phenotypes in intestinal cells, we identified two novel RNA viruses distantly related to known nodaviruses, one infecting specifically C. elegans (Orsay virus), the other C. briggsae (Santeuil virus). Bleaching of embryos cured infected cultures demonstrating that the viruses are neither stably integrated in the host genome nor transmitted vertically. 0.2 µm filtrates of the infected cultures could infect cured animals. Infected animals continuously maintained viral infection for 6 mo (∼50 generations), demonstrating that natural cycles of horizontal virus transmission were faithfully recapitulated in laboratory culture. In addition to infecting the natural C. elegans isolate, Orsay virus readily infected laboratory C. elegans mutants defective in RNAi and yielded higher levels of viral RNA and infection symptoms as compared to infection of the corresponding wild-type N2 strain. These results demonstrated a clear role for RNAi in the defense against this virus. Furthermore, different wild C. elegans isolates displayed differential susceptibility to infection by Orsay virus, thereby affording genetic approaches to defining antiviral loci. This discovery establishes a bona fide viral infection system to explore the natural ecology of nematodes, host-pathogen co-evolution, the evolution of small RNA responses, and innate antiviral mechanisms.

  16. Qualitative evaluation of selective tests for detection of Neospora hughesi antibodies in serum and cerebrospinal fluid of experimentally infected horses.

    Science.gov (United States)

    Packham, Andrea E; Conrad, Patricia A; Wilson, W David; Jeanes, Lisa V; Sverlow, Karen W; Gardner, Ian A; Daft, Barbara M; Marsh, Antoinette E; Blagburn, Byron L; Ferraro, Gregory L; Barr, Bradd C

    2002-12-01

    Neospora hughesi is a newly recognized protozoan pathogen in horses that causes a myeloencephalitis similar to Sarcocystis neurona. There are no validated serologic tests using the gold standard sera that are currently available to detect specific N. hughesi antibodies and, thus, no tests available to detect antemortem exposure or estimate seroprevalence in the horse. The objectives of the present study were to establish a bank of gold standard equine sera through experimental infections with N. hughesi and to assess several serologic tests for the detection of related protozoan antibodies. Seven horses were inoculated with N. hughesi tachyzoites, and 7 horses received uninfected cell culture material. The horses were monitored, and blood and cerebrospinal fluid were collected repeatedly over a 4-mo period. With the sera, 4 different serologic techniques were evaluated. including a whole-parasite lysate enzyme-linked immunosorbent assay (ELISA), a recombinant protein ELISA, a modified direct agglutination test, and an indirect fluorescent antibody test. Qualitative and quantitative evaluation of the results showed that the N. hughesi indirect fluorescent antibody test (IFAT) consistently discriminated between experimentally infected and noninfected horses, using a cutoff of 1:640. Sera from 3 naturally infected horses had titers >1:640. Cerebrospinal fluid in all but I infected horse had very low N. hughesi IFAT titers (<1:160), starting at postinoculation day 30.

  17. Hematologic and IgG responses of heifers experimentally infected with the agent of epizootic bovine abortion.

    Science.gov (United States)

    Coker, Michelle R; Rauw, Wendy M; Nieto, Nathan C; Thain, David; Teglas, Mike B

    2012-09-01

    Epizootic bovine abortion (EBA) is a tick-transmitted abortive disease of beef cattle in the western United States. Infected cattle do not have clinical signs until abortion occurs, usually within the last trimester of gestation. There is little information on the hematologic response of the dam following infection. The purpose of this study was to determine if changes in blood leukocytes and serum IgG concentrations could be detected following experimental infection of pregnant heifers with the etiologic agent of EBA (aoEBA). Twelve Angus heifers were infected during gestation with the aoEBA using an inoculum prepared from the thymus of an infected fetus. Five pregnant heifer controls were given an inoculum prepared from the thymus of an aoEBA-negative calf. PCVs, total and differential leukocyte counts, and serum IgG concentrations were measured weekly following administration of the inocula until abortion or calving. Gross and microscopic examinations were performed on all aborted fetuses to confirm infection. Eleven of 12 heifers in the treatment group aborted, and significant findings were decreased lymphocyte counts at weeks 1 and 14 postinoculation and increased monocyte counts at week 4 compared with control animals. Serum IgG concentrations were significantly increased at weeks 6-8 and 11 in the treatment group. Leukogram changes are subtle in infected cattle. Future research efforts should be aimed at development of an antibody test specific for detection of previously infected animals, which could graze safely on EBA-endemic pastures. © 2012 American Society for Veterinary Clinical Pathology.

  18. Clinical pathology of experimental Schistosoma curassoni infections in sheep and goats.

    Science.gov (United States)

    Vercruysse, J; Fransen, J; Southgate, V R; Rollinson, D; Majeleine, W

    1988-05-01

    The clinical pathology of Schistosoma curassoni infection in sheep and goats was studied for 22 weeks following experimental infection with 7000 and 4000 cercariae, respectively. Excretion of eggs began at week 7 after infection: in goats the numbers increased to 30 to 50 eggs per gram faeces (epg) at weeks 8 to 18, followed by a reduction. In a pregnant goat, epg values increased markedly before and after parturition. The mean faecal egg counts in sheep were lower than in goats, increasing to a maximum level of 30 epg at weeks 16 and 17 after infection. Infected sheep maintained growth rates roughly comparable with controls, whereas infected goats failed to gain as much weight as the controls. Infected goats and sheep produced eosinophil counts of about 3 x 10(3) mm-3, five and eight weeks after infection, respectively. Sheep developed a progressive anaemia from week 11 after infection, in goats blood values remained within normal limits. Differences in serum protein concentration were observed between infected and uninfected goats about nine weeks after infection, but not in sheep. Increased total protein values, hyperglobulinaemia and lowered albumin to globulin ratios were features of infected goats. Serum glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, gamma-glutamyl transferase, total lactate dehydrogenase and bilirubin were not significantly changed. The mean recovery in sheep was 608 worms, in goats 428 worms, but the total tissue egg counts were higher in the latter. Of the total eggs deposited in the goats 92 per cent were found in the liver with 51.5 per cent in the ovine liver. The histopathological changes were studied.

  19. Diurnal fluctuations in nematode egg excretion in naturally and in experimentally infected chickens.

    Science.gov (United States)

    Wongrak, Kalyakorn; Gauly, Matthias; Daş, Gürbüz

    2015-03-15

    We investigated whether nematode egg excretion through feces of naturally or experimentally infected chickens follow certain patterns within a day, which may allow determining the most appropriate sampling time for the highest parasite egg concentration. Feces samples (n=864) from chickens (n=36) with naturally occurring mixed nematode infections (trials N1, N2) or with an experimental Ascaridia galli infection (E) were collected quantitatively every 4h for four consecutive days. Number of eggs per gram of feces (EPG) was determined, and accumulative egg output (AEO) at each sampling time as well as total number of eggs excreted within 24h (eggs per day, EPD) were then estimated. At the end of the collection period, the hens were necropsied and their worm burdens determined. Naturally infected hens harbored Heterakis gallinarum (100%), Capillaria spp. (95.7%) and A. galli (91.3%). The experimental A. galli infection produced patent infections in all the birds. In general, both fecal egg concentration (EPG) and the amount of feces increased (P0.05) between effects of sampling hours and days on EPG and AEO, suggesting the existence of repeatable diurnal fluctuations within each day. Although an association between climatic parameters (e.g., ambient temperature and relative humidity) and the nematode egg excretion was quantified, a causal relationship could not be demonstrated. We conclude that nematode egg excretion through chicken feces in both natural and experimental infections shows repeatable diurnal fluctuations, which may indicate adaptive strategies by nematodes and eventually favor parasite spread. Since analytic sensitivity of fecal egg counts suffers from low egg concentrations in feces, samples taken during the daytime have a higher diagnostic value. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Hepatitis C virus infection: Are there still specific problems with genotype 3?

    Science.gov (United States)

    Gondeau, Claire; Pageaux, Georges Philippe; Larrey, Dominique

    2015-01-01

    Hepatitis C virus (HCV) infection is one of the most common causes of chronic liver disease and the main indication for liver transplantation worldwide. As promising specific treatments have been introduced for genotype 1, clinicians and researchers are now focusing on patients infected by non-genotype 1 HCV, particularly genotype 3. Indeed, in the golden era of direct-acting antiviral drugs, genotype 3 infections are no longer considered as easy to treat and are associated with higher risk of developing severe liver injuries, such as cirrhosis and hepatocellular carcinoma. Moreover, HCV genotype 3 accounts for 40% of all HCV infections in Asia and is the most frequent genotype among HCV-positive injecting drug users in several countries. Here, we review recent data on HCV genotype 3 infection/treatment, including clinical aspects and the underlying genotype-specific molecular mechanisms. PMID:26576095

  1. Dynamic distribution and tissue tropism of classical swine fever virus in experimentally infected pigs

    Science.gov (United States)

    2011-01-01

    Background Classical swine fever (CSF), caused by the Classical swine fever virus (CSFV), is an Office International des Epizooties (OIE) notifiable disease. However, we are far from fully understand the distribution, tissue tropism, pathogenesis, replication and excretion of CSFV in pigs. In this report, we investigated the dynamic distribution and tissue tropism of the virus in internal organs of the experimentally infected pigs using real-time RT-PCR and immunohistochemistry (IHC). Results A relative quantification real-time PCR was established and used to detect the virus load in internal organs of the experimentally infected pigs. The study revealed that the virus was detected in all 21 of the internal organs and blood collected from pigs at day 1 to day 8 post infections, and had an increasing virus load from day 1 to day 8 post infections. However, there was irregular distribution virus load in most internal organs over the first 2 days post infection. Blood, lymphoid tissue, pancreas and ileum usually contain the highest viral loads, while heart, duodenum and brain show relatively low viral loads. Conclusions All the data suggest that CSFV had an increasing virus load from day 1 to day 8 post infections in experimentally infected pigs detected by real-time RT-PCR, which was in consistent with the result of the IHC staining. The data also show that CSFV was likely to reproduce in blood, lymphoid tissue, pancreas and the ileum, while unlikely to replicate in the heart, duodenum and brain. The results provide a foundation for further clarification of the pathogenic mechanism of CSFV in internal organs, and indicate that blood, lymphoid tissue, pancreas and ileum may be preferred sites of acute infection. PMID:21535885

  2. Potential Role of Carvedilol in the Cardiac Immune Response Induced by Experimental Infection with Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Aline Luciano Horta

    2017-01-01

    Full Text Available Trypanosoma cruzi causes a cardiac infection characterized by an inflammatory imbalance that could become the inciting factor of the illness. To this end, we evaluated the role of carvedilol, a beta-blocker with potential immunomodulatory properties, on the immune response in C57BL/6 mice infected with VL-10 strain of T. cruzi in the acute phase. Animals (n=40 were grouped: (i not infected, (ii infected, (iii infected + carvedilol, and (iv not infected + carvedilol. We analyzed parameters related to parasitemia, plasma levels of TNF, IL-10, and CCL2, and cardiac histopathology after the administration of carvedilol for 30 days. We did not observe differences in the maximum peaks of parasitemia in the day of their detection among the groups. The plasma TNF was elevated at 60 days of infection in mice treated or not with carvedilol. However, we observed a decreased CCL2 level and increased IL-10 levels in those infected animals treated with carvedilol, which impacted the reduction of the inflammatory infiltration in cardiac tissue. For this experimental model, carvedilol therapy was not able to alter the levels of circulating parasites but modulates the pattern of CCL2 and IL-10 mediators when the VL10 strain of T. cruzi was used in C57BL6 mice.

  3. Immunologic responses in corn snakes (Pantherophis guttatus) after experimentally induced infection with ferlaviruses.

    Science.gov (United States)

    Neul, Annkatrin; Schrödl, Wieland; Marschang, Rachel E; Bjick, Tina; Truyen, Uwe; von Buttlar, Heiner; Pees, Michael

    2017-04-01

    OBJECTIVE To measure immunologic responses of snakes after experimentally induced infection with ferlaviruses. ANIMALS 42 adult corn snakes (Pantherophis guttatus) of both sexes. PROCEDURES Snakes were inoculated intratracheally with genogroup A (n = 12), B (12), or C (12) ferlavirus (infected groups) or cell-culture supernatant (6; control group) on day 0. Three snakes from each infected group were euthanized on days 4, 16, 28, and 49, and 3 snakes from the control group were euthanized on day 49. Blood samples were collected from live snakes on days -6 (baseline), 4, 16, 28, and 49. Hematologic tests were performed and humoral responses assessed via hemagglutination-inhibition assays and ELISAs. Following euthanasia, gross pathological and histologic evaluations and virus detection were performed. RESULTS Severity of clinical signs of and immunologic responses to ferlavirus infection differed among snake groups. Hematologic values, particularly WBC and monocyte counts, increased between days 4 and 16 after infection. A humoral response was identified between days 16 and 28. Serum IgM concentrations increased from baseline earlier than IgY concentrations, but the IgY relative increase was higher at the end of the study. The hemagglutination-inhibition assay revealed that the strongest reactions in all infected groups were against the strain with which they had been infected. Snakes infected with genogroup A ferlavirus had the strongest immune response, whereas those infected with genogroup B had the weakest responses. CONCLUSIONS AND CLINICAL RELEVANCE Results of this experimental study suggested that the ferlavirus strain with the highest virulence induced the weakest immune response in snakes.

  4. Selective Infection of Antigen-Specific B Lymphocytes by Salmonella Mediates Bacterial Survival and Systemic Spreading of Infection

    Science.gov (United States)

    de Wit, Jelle; Martinoli, Chiara; Zagato, Elena; Janssen, Hans; Jorritsma, Tineke; Bar-Ephraïm, Yotam E.; Rescigno, Maria; Neefjes, Jacques; van Ham, S. Marieke

    2012-01-01

    Background The bacterial pathogen Salmonella causes worldwide disease. A major route of intestinal entry involves M cells, providing access to B cell-rich Peyer’s Patches. Primary human B cells phagocytose Salmonella typhimurium upon recognition by the specific surface Ig receptor (BCR). As it is unclear how Salmonella disseminates systemically, we studied whether Salmonella can use B cells as a transport device for spreading. Methodology/Principal Findings Human primary B cells or Ramos cell line were incubated with GFP-expressing Salmonella. Intracellular survival and escape was studied in vitro by live cell imaging, flow cytometry and flow imaging. HEL-specific B cells were transferred into C57BL/6 mice and HEL-expressing Salmonella spreading in vivo was analyzed investigating mesenteric lymph nodes, spleen and blood. After phagocytosis by B cells, Salmonella survives intracellularly in a non-replicative state which is actively maintained by the B cell. Salmonella is later excreted followed by reproductive infection of other cell types. Salmonella-specific B cells thus act both as a survival niche and a reservoir for reinfection. Adoptive transfer of antigen-specific B cells before oral infection of mice showed that these B cells mediate in vivo systemic spreading of Salmonella to spleen and blood. Conclusions/Significance This is a first example of a pathogenic bacterium that abuses the antigen-specific cells of the adaptive immune system for systemic spreading for dissemination of infection. PMID:23209805

  5. Experimental porcine rubulavirus (La Piedad-Michoacan virus) infection in pregnant gilts.

    Science.gov (United States)

    Hernández-Jáuregui, P; Ramírez Mendoza, H; Mercado García, C; Moreno-López, J; Kennedy, S

    2004-01-01

    Porcine rubulavirus (La Piedad-Michoacan virus) (PoRV-LPMV) is a member of the Paramyxoviridae family that causes encephalitis in young piglets and infertility in adult sows and boars. Infertility in sows naturally infected by PoRV-LPMV is characterized by an increased number of returns to oestrus, stillbirths and mummified fetuses. In this study, nine seronegative gilts were inoculated intranasally with the PAC-3 strain of PoRV-LPMV at week 6 or 10 of gestation. These animals were then killed at weeks 8 or 15 of gestation (seven gilts) or after natural parturition (two gilts). Four control gilts were mock-infected at gestation week 6 or 10 and killed between 2 and 4 weeks later. Gross lesions of focal congestion and haemorrhage were seen in the placenta and endometrium of one gilt infected at gestation week 6 and one infected at gestation week 10. PoRV-LPMV was isolated, at 2-6 weeks post-inoculation (pi), from lung, tonsils, ovary, placenta, uterus and lymph nodes of three of the gilts infected at gestation week 6 and at 2-3 weeks pi from lung, tonsil and ovary of two gilts infected at gestation week 10. Many of the fetuses of eight infected gilts were smaller than normal and had dermal ecchymoses. Dehydrated or mummified fetuses were present in six of the infected gilts but not in any control animal. PoRV-LPMV was isolated from brain, lung and liver of fetuses from two gilts infected at gestation week 6, and from two infected at gestation week 10. These results indicate that, after experimental infection, PoRV can replicate in tissues of seronegative pregnant gilts, cross the placenta, and cause fetal death and mummification.

  6. Schmallenberg virus detection in bovine semen after experimental infection of bulls.

    NARCIS (Netherlands)

    Poel, van der W.H.M.; Parlevliet, J.M.; Verstraten, E.R.A.M.; Kooi, E.A.; Hakze-van der Honing, van der R.W.; Stockhofe-Zurwieden, N.

    2014-01-01

    To study Schmallenberg virus (SBV) excretion in bovine semen after experimental infection, two bulls were inoculated subcutaneously with a SBV isolate (1 ml Vero cell culture 106 TCID50). After inoculation (at day 0), semen was collected daily from both animals for 21 days and samples were tested

  7. Pathology of Experimental Encephalitozoon cuniculi Infection in Immunocompetent and Immunosuppressed Mice in Iraq

    Directory of Open Access Journals (Sweden)

    Hafidh I. Al-Sadi

    2014-01-01

    Full Text Available This study was performed to evaluate pathology of experimental Encephalitozoon cuniculi (Iraqi isolate infection in normal and immunosuppressed mice. Pathological changes were not seen in negative control mice while secondary bacterial infections were noted in the lungs, kidneys, and heart of mice given dexamethasone. Typical E. cuniculi infection lesions were found in brain, livers, lungs, and kidneys of mice given 107  E. cuniculi spores/mouse orally. These lesions were in the form of nonsuppurative meningoencephalitis with vasculitis in brain, interstitial inflammation with infiltration of both lymphocytes and plasma cells in lung tissue, and nonsuppurative interstitial (focal and diffuse nephritis, presence of vacuole containing mature and immature spores in enterocytes within the tips of villi, and lymphoiod hyperplasia of the white pulp and vasculitis of the intratrabecular vessels. Mice that were given 107  E. cuniculi spores/mouse orally showed lesions similar to those observed in the previous group (vasculitis and granulomas but the lesions were more severe and widespread. In conclusion, this is the first report of experimental E. cuniculi infection induced by E. cuniculi isolated from a naturally infected rabbit in Iraq and that infection became more severe and widespread upon the administration of dexaethasone.

  8. Experimental Infection of Taenia saginata eggs in Bali Cattle: Distribution and Density of Cysticercus bovis

    Directory of Open Access Journals (Sweden)

    Nyoman Sadra Dharmawan

    2009-12-01

    Full Text Available The objective of this study was to observe the development, distribution, and infection density ofTaenia saginata metacestodes in Bali cattle. Three Bali cattle were experimentally infected with T. saginataeggs which were collected from taeniasis patients. The experimental animal was inoculated with : i1000,00 T. saginata; ii 500,000 eggs; and iii 1,000,000 eggs, respectivelly 100,000 (cattle 1, 500,000(cattle 2, and 1,000,000 (cattle 3 T. saginata eggs, respectively. To observe the development of cysticerci,all cattle were slaughtered at 24 weeks post infection. To observe their distribution and density, slicingwas done to the cattle?s tissues. The study results showed that cysts were found distributed to all muscletissues and some visceral organs such as heart, diaphragm, lungs, and kidney of the cattle infected with100,000 and 500,000 T. saginata eggs. Density of the cyst was in the range of 11 to 95 cysts per 100 gramsof tissue. The highest density was noted in the heart (58/100 grams and in diaphragm (55/100 grams.This study has confirmed that T. saginata eggs derived from taeniasis patient in Bali, if infected to Balicattle can develop and spread to all muscle tissues and some visceral organs. From this study it wasconcluded that it is necessary to include the heart in the meat inspection at slaughter house for possibilityof T. saginata cyst infection.$?

  9. Experimental infection of Artibeus intermedius with a vampire bat rabies virus.

    Science.gov (United States)

    Obregón-Morales, Cirani; Aguilar-Setién, Álvaro; Perea Martínez, Leonardo; Galvez-Romero, Guillermo; Martínez-Martínez, Flor Olivia; Aréchiga-Ceballos, Nidia

    2017-06-01

    Experimental infection of Artibeus intermedius, the great fruit-eating bat, was performed with vampire bat rabies isolates. Bats (n=35) were captured in the wild and quarantined prior to experimental infection. No rabies antibodies were detected by rapid fluorescent focus inhibition test (RFFIT) prior to infection. Three doses of rabies virus (RV) and three different routes of infection were used. One out of 35 bats died without showing any clinical signs at day 14 and was positive for rabies. None of the 34 other bats showed clinical signs for rabies, but high antibody titers were detected post-inoculation, suggesting either innate immune response to the vampire bat rabies virus or possible pre-exposure to RV and inoculation leading to a booster effect. Rabies virus was detected by hemi-nested RT-PCR (hnRT-PCR) in the brain (n=3), stomach (n=1) of bats that were negative by immunofluorescence and that survived rabies infection. The bat that died on day 14 was positive by hnRT-PCR on the brain, heart and liver. These results suggest that either previous non-lethal exposure to RV or natural low susceptibility to vampire bat viruses somehow protected Artibeus intermedius from clinical rabies infection leading to a marginal lethality effect on this bats species population in the wild. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Detection of Toxoplasma gondii DNA in sera samples of mice experimentally infected

    Directory of Open Access Journals (Sweden)

    H. Langoni

    2006-04-01

    Full Text Available Detection of Toxoplasma gondii (T. gondii DNA in blood can help to diagnose the disease in its acute phase; however, it must be considered that hemoglobin, present in blood, can inhibit polymerase activity, making impracticable the detection of DNA in samples. Mice were experimentally infected via oral route with ME49 and BTU2 strains cysts and RH strain tachyzoites; polymerase chain reaction was used to detect T. gondii DNA in mice sera 18, 24, 48, 96, and 192 hours post infection (PI. Toxoplama gondii DNA was detected in only one animal infected with BTU2 strain, genotype III (isolated from a dog with neurological signs 18 hours PI. The agent's DNA was not detected in any sample of the other experimental groups. New studies must be carried out to verify the technique sensitivity in researches on this agent's genetic material using sera samples of acute-phase toxoplasmosis patients, especially in cases of immunosuppression.

  11. Efficacy of toltrazuril against experimental infections with Eimeria labbeana and E. columbarum in racing pigeons.

    Science.gov (United States)

    Van Reeth, K; Vercruysse, J

    1993-01-01

    The efficacy of toltrazuril against heavy experimental Eimeria labbeana and E. columbarum infections in racing pigeons was investigated. Pigeons were treated with toltrazuril at a dose of 20 mg/kg body weight before, during, and after the pre-patent period. In pigeons treated during pre-patency (1-5 days postinoculation [PI]), a 99.9% reduction in oocyst output was observed at day 7 PI. Treatment during patency (6-7 days PI) resulted in an interruption of oocyst shedding within 3 to 4 days. Pigeons treated with toltrazuril up to 14 days before the experimental infection showed on average a reduction of more than 97% in the number of oocysts in individual fecal samples. Finally, at reinfection, the immune response of pigeons previously treated during pre-patency was not altered compared with the response of infected unmedicated controls.

  12. Rapid and widely disseminated acute phase protein response after experimental bacterial infection of pigs

    DEFF Research Database (Denmark)

    Skovgaard, Kerstin; Mortensen, Shila; Boye, Mette

    2009-01-01

    The acute phase protein response is a well-described generalized early host response to tissue injury, inflammation and infection, observed as pronounced changes in the concentrations of a number of circulating serum proteins. The biological function of this response and its interplay with other...... infection in pigs. The lung infection was established with the pig specific respiratory pathogen Actinobacillus pleuropneumoniae. Quantitative real-time PCR based expression analysis were performed on samples from liver, tracheobronchial lymph node, tonsils, spleen and on blood leukocytes, supplemented...... with measurements of interleukin-6 and selected acute phase proteins in serum. C-reactive protein and serum amyloid A were clearly induced 14-18 h after infection. Extrahepatic expression of acute phase proteins was found to be dramatically altered as a result of the lung infection with an extrahepatic acute phase...

  13. Experimental infection with the small intestinal trematode, Haplorchis pumilio, in young dogs

    DEFF Research Database (Denmark)

    Nissen, Sofie; Nguyen, Lan Anh Thi; Dalsgaard, Anders

    2013-01-01

    Fishborne zoonotic trematodes (FZT) are highly prevalent in Southeast Asia. Recent studies on the role of domestic animals in the transmission of FZT in Northern Vietnam found that dogs, mainly infected with Haplorchis pumilio, contributed widely to the transmission of FZT. On this background, we...... conducted an experimental infection with H. pumilio to elucidate population dynamics and host reactions in dogs. Eight household-reared dogs (3-6 months old), were each orally infected with 500 H. pumilio metacercariae obtained by artificial digestion of naturally infected fish. Another eight dogs were...... included as uninfected controls. Faecal examination for eggs was performed twice weekly using a sieving and sedimentation technique. Body temperature and weight of the dogs were measured as was total white blood cells, blood eosinophils and packed cell volume. Subsets of dogs were examined post...

  14. Induced expression of the antimicrobial peptide melittin inhibits experimental infection by Mycoplasma gallisepticum in chickens.

    Science.gov (United States)

    Lazarev, Vassili N; Stipkovits, Laszlo; Biro, Judit; Miklodi, Dora; Shkarupeta, Marina M; Titova, Galina A; Akopian, Tatiana A; Govorun, Vadim M

    2004-05-01

    The in vivo action of the antimicrobial peptide melittin, expressed from a recombinant plasmid vector, on chickens experimentally infected with Mycoplasma gallisepticum was studied. The plasmid vector pBI/mel2/rtTA includes the melittin gene under the control of an inducible tetracycline-dependent human cytomegalovirus promoter and the gene coding for the trans-activation protein rtTA. Aerosol administration of the vector, followed by infecting the chickens with M. gallisepticum 1226, is shown to inhibit development of infection. The inhibitory action was confirmed by a complex of clinical, pathomorphological, histological and serological studies, and also by comparing the M. gallisepticum reisolation frequency from the respiratory tract and internal organs. The data suggest that plasmid vectors expressing genes of antimicrobial peptides can be considered as potential agents for the prevention and treatment of mycoplasma infections in poultry farming.

  15. Lactation curve and milk quality of goats experimentally infected with Trypanosoma vivax.

    Science.gov (United States)

    Lopes, Francisco Canindé; de Paiva, Kaliane Alessandra Rodrigues; Coelho, Wesley Adson Costa; Nunes, Francisco Vítor Aires; da Silva, Jardel Bezerra; de Gouveia Mendes da Escóssia Pinheiro, Carolina; de Macêdo Praça, Layanne; Silva, Jean Berg Alves; Alves Freitas, Carlos Iberê; Batista, Jael Soares

    2016-08-01

    The present study aimed to evaluate the effects of Trypanosoma vivax infection on the shape of the lactation curve and the milk quality of dairy goats experimentally infected with T. vivax. In total, twenty Saanen goats, aged 26-30 months and the same number of calving (two calvings), were divided into two experimental groups: an infected group, consisting of ten goats intravenously infected with 0.5 ml of blood containing approximately 1.25 × 10(5) trypomastigotes of T. vivax and ten uninfected animals as the control group. Clinical tests and hematocrit, parasitemia, and serum biochemistry evaluations were performed on all of the goats. Milk production was measured daily for 152 days by hand milking the goats and weighing the milk. Every seven days, physiochemical analyses were performed to evaluate the milk. Wood's nonlinear model was used to analyze the lactation curve parameters. The infected goats had high levels of parasitemia and hyperthermia, significantly reduced hematocrit, serum total protein, albumin, and glucose levels and increased cholesterol and urea concentrations. Wood's model indicated that the milk production of goats in the infected group declined sharply over a short period of time and produced a flattened yield curve and significant difference (P physico-chemical properties of the milk, including the fat content, defatted dry extracts (DDE) and protein content, decreased significantly (P < 0.05) in the goats in the infected group compared with those in the control group. The T. vivax-infected goats showed reduction in milk production, persistence of lactation, and fat levels, the defatted dry extract (DDE) content, and protein, changing the quality of milk. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. An immunohistochemical study of Flexibacter psychrophilus infection in experimentally and naturally infected rainbow trout (Oncorhynchus mykiss) fry

    DEFF Research Database (Denmark)

    Evensen, O.; Lorenzen, Ellen

    1996-01-01

    An immunohistochemical method is described for the detection of Flexibacter psychrophilus in formalin-fixed, parafiin-wax-embedded fry of rainbow trout. Rabbit antiserum as well as rainbow trout hyperimmune serum were used in the study. The distribution and tissue localization of the bacterium...... and experimentally infected fry showed that there was a localization of bacteria in the monocyte-macrophage system, in skin lesions, and in the retina and the choroid gland of the eye. The dermal changes included superficial or deep ulcers extending to the subcutaneous tissue or the musculature accompanied...... polymorphonuclear) cells. F. psychrophilus infection in rainbow trout fry involves the monocyte-macrophage system extensively, and the concurrent localization of bacteria in the skin ulcers and retinal inflammation points to the probable involvement of the bacterium in the development of the lesions which...

  17. Infectivity of DWV associated to flower pollen: experimental evidence of a horizontal transmission route.

    Directory of Open Access Journals (Sweden)

    Maurizio Mazzei

    Full Text Available Deformed wing virus (DWV is a honeybee pathogen whose presence is generally associated with infestation of the colony by the mite Varroa destructor, leading to the onset of infections responsible for the collapse of the bee colony. DWV contaminates bee products such as royal jelly, bee-bread and honey stored within the infected hive. Outside the hive, DWV has been found in pollen loads collected directly from infected as well as uninfected forager bees. It has been shown that the introduction of virus-contaminated pollen into a DWV-free hive results in the production of virus-contaminated food, whose role in the development of infected bees from virus-free eggs has been experimentally demonstrated. The aim of this study was twofold: (i to ascertain the presence of DWV on pollen collected directly from flowers visited by honeybees and then quantify the viral load and (ii determine whether the virus associated with pollen is infective. The results of our investigation provide evidence that DWV is present on pollen sampled directly from visited flowers and that, following injection in individuals belonging to the pollinator species Apis mellifera, it is able to establish an active infection, as indicated by the presence of replicating virus in the head of the injected bees. We also provide the first indication that the pollinator species Osmia cornuta is susceptible to DWV infection.

  18. Identification of Wb123 as an Early and Specific Marker of Wuchereria bancrofti Infection

    Science.gov (United States)

    Kubofcik, Joseph; Fink, Doran L.; Nutman, Thomas B.

    2012-01-01

    Background The current antibody tests used for monitoring in lymphatic filariasis (LF) elimination programs suffer from poor specificity because of the considerable geographical overlap with other filarial infections such as Loa loa (Ll), Onchocerca volvulus (Ov), and Mansonella perstans (Mp). Methods Using bioinformatics to assemble into contigs 2048 expressed sequence tags (ESTs) from the L3 infective larvae of W. bancrofti (Wb), these were next assessed for homology to known proteins and nucleotides and to similar assemblies of L3 larval ESTs of B. malayi (Bm – n = 5068), Ov (n = 4166), and Ll (n = 3315). Nineteen potential L3- and Wb- and/or Bm-specific antigens were identified. Sixteen of the 19 antigens could be expressed as fusion proteins with Renilla luciferase (Ruc); these were used in a rapid Luciferase Immunopreciptation System (LIPS) assay. Results One of the 16 expressed antigens (Wb123) was both highly immunogenic and specific for Wb. Using Wb123-based IgG and IgG4 LIPS assays on well-defined sera from normal North Americans and those infected exclusively with intestinal helminths, we could detect all of the Wb-infected individuals (from diverse geographic regions) with 100% sensitivity and 100% specificity. Using sera from exclusively Ll-infected, Ov-infected Mp-infected or Bm-infected subjects as the negative comparator, the sensitivities were between 98–100% and the specificities ranged between 84–100% (for IgG anti-Wb123) and between 98–100% (for IgG4 anti-Wb123). Blinded assessments using panels of sera from various Wb-, Bm- or non-Wb helminth-infected subjects demonstrated equally high degrees of sensitivity and specificity. Significance We have identified a Wb-encoded antigen that can be used both as a rapid, high throughput tool to diagnose individual Wb infections and as a sensitive method for early detection of recrudescent infections in areas of control and for mapping new areas of Wb transmission. PMID:23236529

  19. Dietary cinnamaldehyde enhances acquisition of specific antibodies following helminth infection in pigs

    DEFF Research Database (Denmark)

    Williams, Andrew R.; Hansen, Tina V. A.; Krych, Lukasz

    2017-01-01

    Dietary phytonutrients such as cinnamaldehyde (CA) may contribute to immune function during pathogen infections, and CA has been reported to have positive effects on gut health when used as feed additive for livestock. Here, we investigated whether CA could enhance antibody production and specific...... immune responses during infection with an enteric pathogen. We examined the effect of dietary CA on plasma antibody levels in parasite-naïve pigs, and subsequently acquisition of humoral immune responses during infection with the parasitic nematode Ascaris suum. Parasite-naïve pigs fed diets supplemented......) and glucose transporter 2 (SLC2A2) in the jejunal mucosa of A.suum-infected pigs. Dietary CA induced only limited changes in the composition of the prokaryotic gut microbiota of A. suum-infected pigs, and in vitro experiments showed that CA did not directly induce proliferation or increase secretion of Ig...

  20. Prostate involvement during sexually transmitted infections as measured by prostate-specific antigen concentration.

    Science.gov (United States)

    Sutcliffe, S; Nevin, R L; Pakpahan, R; Elliott, D J; Cole, S R; De Marzo, A M; Gaydos, C A; Isaacs, W B; Nelson, W G; Sokoll, L J; Zenilman, J M; Cersovsky, S B; Platz, E A

    2011-08-23

    We investigated prostate involvement during sexually transmitted infections by measuring serum prostate-specific antigen (PSA) as a marker of prostate infection, inflammation, and/or cell damage in young, male US military members. We measured PSA before and during infection for 299 chlamydia, 112 gonorrhoea, and 59 non-chlamydial, non-gonococcal urethritis (NCNGU) cases, and 256 controls. Chlamydia and gonorrhoea, but not NCNGU, cases were more likely to have a large rise (40%) in PSA than controls (33.6%, 19.1%, and 8.2% vs 8.8%, P<0.0001, 0.021, and 0.92, respectively). Chlamydia and gonorrhoea may infect the prostate of some infected men.

  1. Diagnosis of enzootic pneumonia in Danish cattle: reverse transcription-polymerase chain reaction assay for detection of bovine respiratory syncytial virus in naturally and experimentally infected cattle

    DEFF Research Database (Denmark)

    Larsen, Lars Erik; Tjørnehøj, Kirsten; Viuff, B.

    1999-01-01

    A reverse transcription-polymerase chain reaction (RT-PCR) assay was developed for detection of bovine respiratory syncytial virus (BRSV) in lung tissue of naturally and experimentally infected cattle. Primers were selected from the gene coding the F fusion protein, which is relatively conserved...... among BRSV isolates. The RT-PCR assay was highly specific, it yielded positive reactions only when performed on BRSV-infected cell cultures or tissues. The detection limit of the RT-PCR assay was assessed as 5 TCID50. BRSV was detected in tissues of the respiratory tract and in the tracheobroncheal...... lymph node of calves euthanized 2-8 days after experimental infection with BRSV, whereas samples of other tissues and samples from mock-infected animals were negative at all time points. Examination of lung samples from 8 different regions of the lungs revealed that although the virus was most often...

  2. Dynamics of a Fractional Order HIV Infection Model with Specific Functional Response and Cure Rate

    Directory of Open Access Journals (Sweden)

    Adnane Boukhouima

    2017-01-01

    Full Text Available We propose a fractional order model in this paper to describe the dynamics of human immunodeficiency virus (HIV infection. In the model, the infection transmission process is modeled by a specific functional response. First, we show that the model is mathematically and biologically well posed. Second, the local and global stabilities of the equilibria are investigated. Finally, some numerical simulations are presented in order to illustrate our theoretical results.

  3. Viral respiratory infections in patients with chronic non-specific lung disease (CNSLD)

    OpenAIRE

    Roldaan, A.C.

    1981-01-01

    textabstractIt is a well known clinical phenomenon that patients suffering from bronchial obstructive disorders, usually covered by the term chronic non-specific lung disease (CNSLD) tend to react with exacerbations of their disease in the course of respiratory infections, especially if a viral or mycoplasmal agent is involved. However, there is no uniform opinion about the relative importance of viral respiratory infections in this respect, and much of the background of the features observed...

  4. First report of Dientamoeba fragilis infection explaining acute non-specific abdominal pain

    Directory of Open Access Journals (Sweden)

    E Vassalou

    2016-01-01

    Full Text Available Dientamoeba fragilis is now considered a potentially emerging gastrointestinal pathogen in both developing and developed countries. We first report an autochthonous case of D. fragilis infection in Greece. A 49-year-old female with acute non-specific abdominal pain required emergency surgical admission for active observation and repeated assessment. To the best of our knowledge, this is the first reported case of acute unexplained abdominal pain finally attributed to D. fragilis infection using microscopic and molecular methods.

  5. First report of Dientamoeba fragilis infection explaining acute non-specific abdominal pain.

    Science.gov (United States)

    Vassalou, E; Vassalos, C M; Spanakos, G; Fotopoulos, A; Dounias, G; Kalofolias, P; Vrioni, G; Tsakris, A

    2016-01-01

    Dientamoeba fragilis is now considered a potentially emerging gastrointestinal pathogen in both developing and developed countries. We first report an autochthonous case of D. fragilis infection in Greece. A 49-year-old female with acute non-specific abdominal pain required emergency surgical admission for active observation and repeated assessment. To the best of our knowledge, this is the first reported case of acute unexplained abdominal pain finally attributed to D. fragilis infection using microscopic and molecular methods.

  6. Imaging experimental infective endocarditis with indium-111-labeled blood cellular components

    Energy Technology Data Exchange (ETDEWEB)

    Riba, A.L.; Thakur, M.L.; Gottschalk, A.; Andriole, V.T.; Zaret, B.L.

    1979-02-01

    The capability of radionuclide imaging to detect experimental aortic valve infective endocarditis was assessed with indium-111 (/sup 111/In)-labeled blood cells. Sequential cardiac imaging and tissue distribution studies were obtained in 17 rabbits with infective endocarditis after administration of /sup 111/-In-platelets and in five after /sup 111/In-polymorphonuclear leukocytes. Forty-eight to 72 hours after platelet administration, in vivo imaging demonstrated abnormal /sup 111/In uptake in all animals in the region of the aortic valve in an anatomically distinct pattern. Images of the excised heart showed discrete cardiac uptake conforming to the in vivo image and gross pathological examination. /sup 111/In platelet uptake in vegetations from the 17 animals averaged 240 +- 41 times greater than that in normal myocardium and 99 +- 15 times greater uptake in blood. In contrast, /sup 111/In-leukocyte cardiac imaging showed no abnormal aortic valve uptake 24 hours after tracer administration and the lesion myocardium activity ratio was only 5 +- 2 (3 +- 1 for lesion/blood activity). Four normal rabbits demonstrated neither positive /sup 111/In platelet scintigraphs nor abnormal cardiac tissue uptake. Likewise, noncellular /sup 111/In was not concentrated to any significant extent in three animals with infective endocarditis.This study demonstrates that /sup 111/In platelet, but not leukocyte cardiac imaging, is a sensitive technique for detecting experimental infective endocarditis. The imaging data conform to the cellular pathology of the infective endocarditis vegetation.

  7. Imaging experimental infective endocarditis with indium-111-labeled blood cellular components. [Rabbits, aortic valve

    Energy Technology Data Exchange (ETDEWEB)

    Riba, A.L.; Thakur, M.L.; Gottschalk, A.; Andriole, V.T.; Zaret, B.L.

    1979-02-01

    The capability of radionuclide imaging to detect experimental aortic valve infective endocarditis was assessed with indium-111 (/sup 111/In)-labeled blood cells. Sequential cardiac imaging and tissue distribution studies were obtained in 17 rabbits with infective endocarditis after administration of /sup 111/In-platelets and in five after /sup 111/In-polymorphonuclear leukocytes. Forty-eight to 72 hours after platelet administration, in vivo imaging demonstrated abnormal /sup 111/In uptake in all animals in the region of the aortic valve in an anatomically distinct pattern. Images of the excised heart showed discrete cardiac uptake conforming to the in vivo image and gross pathological examination. /sup 111/In-platelet uptake in vegetations from the 17 animals averaged 240 +- 41 times greater than that in normal myocardium and 99 +- 15 times greater uptake in blood. In contrast, /sup 111/In-leukocyte cardiac imaging showed no abnormal aortic valve uptake 24 hours after tracer administration and the lesion myocardium activity ratio was only 5 +- 2 (3 +- 1 for lesion/blood activity). Four normal rabbits demonstrated neither positive /sup 111/In-platelet scintigraphs nor abnormal cardiac tissue uptake. Likewise, noncellular /sup 111/In was not concentrated to any significant extent in three animals with infective endocarditis. This study demonstrates that /sup 111/In-platelet, but not leukocyte cardiac imaging, is a sensitive technique for detecting experimental infective endocarditis. The imaging data conform to the cellular pathology of the infective endocarditis vegetation.

  8. Specific-Pathogen-Free Pigs as an Animal Model for Studying Chlamydia trachomatis Genital Infection

    OpenAIRE

    Vanrompay, Daisy; Hoang, Thi Q. T.; De Vos, Liselotte; Verminnen, Kristel; Harkinezhad, Taher; Chiers, Koen; Morré, Servaas A.; Cox, Eric

    2005-01-01

    The purpose of the present study was to evaluate pigs as a large-animal model for female genital infection with two Chlamydia trachomatis human serovar E strains. Sixteen-week-old specific-pathogen-free female pigs (gilts) were intravaginally infected with the trachoma type E reference strain Bour or the urogenital serovar E strain 468. Several conclusions can be drawn from our findings on the pathogenicity of a primary C. trachomatis genital infection in gilts. First of all, we demonstrated ...

  9. Metabolomic profiling of faecal extracts from Cryptosporidium parvum infection in experimental mouse models.

    Directory of Open Access Journals (Sweden)

    Josephine S Y Ng Hublin

    Full Text Available Cryptosporidiosis is a gastrointestinal disease in humans and animals caused by infection with the protozoan parasite Cryptosporidium. In healthy individuals, the disease manifests mainly as acute self-limiting diarrhoea, but may be chronic and life threatening for those with compromised immune systems. Control and treatment of the disease is challenged by the lack of sensitive diagnostic tools and broad-spectrum chemotherapy. Metabolomics, or metabolite profiling, is an emerging field of study, which enables characterisation of the end products of regulatory processes in a biological system. Analysis of changes in metabolite patterns reflects changes in biochemical regulation, production and control, and may contribute to understanding the effects of Cryptosporidium infection in the host environment. In the present study, metabolomic analysis of faecal samples from experimentally infected mice was carried out to assess metabolite profiles pertaining to the infection. Gas-chromatography mass spectrometry (GC-MS carried out on faecal samples from a group of C. parvum infected mice and a group of uninfected control mice detected a mean total of 220 compounds. Multivariate analyses showed distinct differences between the profiles of C. parvum infected mice and uninfected control mice,identifying a total of 40 compounds, or metabolites that contributed most to the variance between the two groups. These metabolites consisted of amino acids (n = 17, carbohydrates (n = 8, lipids (n = 7, organic acids (n = 3 and other various metabolites (n = 5, which showed significant differences in levels of metabolite abundance between the infected and uninfected mice groups (p < 0.05. The metabolites detected in this study as well as the differences in abundance between the C. parvum infected and the uninfected control mice, highlights the effects of the infection on intestinal permeability and the fate of the metabolites as a result of nutrient scavenging by the

  10. Schmallenberg virus infection in South American camelids: Field and experimental investigations.

    Science.gov (United States)

    Schulz, Claudia; Beer, Martin; Hoffmann, Bernd

    2015-11-18

    During the first epizootic wave of the novel, teratogenic Schmallenberg virus (SBV, Orthobunyavirus) in ruminants in Northern Europe, serological evidence of a previous SBV-infection demonstrated that South American camelids (SAC) are also susceptible to SBV. However, their potential role in SBV spread remains unknown. To investigate the prevalence and course of SBV-infection in SAC, a German field study and an animal trial with three llamas and three alpacas were conducted. From September 2012 to December 2013, 313 of 502 SAC (62.35%) were found SBV seropositive, but negative for SBV-RNA. The estimated between-district (94.23% of 52) and median within-district (71.43%) and herd (73.13%) SBV seroprevalence in German SAC was similar to the seroprevalence reported in cattle herds and sheep flocks at the time. An age of >1 year was found a statistically significant risk factor for SBV-infection, which could be explained by the spatio-temporal spread of SBV in Germany during the study period. No clinical signs or an increase of abortion and congenital malformation associated with SBV-infection in SAC were reported by the study participants. Similar to SBV-infected ruminants, SBV-RNAemia in experimentally SBV-infected SAC was detected for a short time between days 3 and 7 after infection (dpi), and seroconversion occurred between 9 and 21 dpi. Despite the similar virological and serological results, the lack of clinical signs and congenital malformation associated with SBV-infection suggests that SBV causes subclinical infection in SAC. However, their role as reservoirs in the spread of SBV has to be further investigated. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Persistence of viral RNA in the brain of experimentally infected mice with coxsackievirus B5

    OpenAIRE

    Sobotova Z.; Marosova L.; Badurova M.; Sojka M.; Borsanyiova M.; Stipalova D.; Bopegamage S.

    2011-01-01

    The aim of our study was to follow the persistence of viral RNA in selected organs of experimentally infected with coxsackievirus (CV) B5 strains from different sources such as a patient’s sample, an environmental sample and a prototype virus strain. Methods . CD-1 mice were infected with CVB5 strain Faulkner the prototype, CVB5 – isolate from treated sewage waste and isolate from patient’s stool sample both identified as CVB5. The viral RNA was detected by RT-PCR using enterovirus primers sp...

  12. Experimental infections with rifampicin-resistant Clostridium perfringens strains in broiler chickens using isolator facilities

    DEFF Research Database (Denmark)

    Pedersen, Karl; Bjerrum, Lotte; Nauerby, Birgitte

    2003-01-01

    Experimental infection studies were carried out on the ability of three Clostridium perfringens type A rifampicin-resistant strains to colonize the intestinal tract of broiler chickens kept in isolators from 1-day-old. Various doses of C. perfringens were given orally at 22 days, 9 days or at 1 day...... replaced by naturally occurring strains of C. perfringens in all groups but they persisted for considerably longer in chickens inoculated at 1-day-old or at 9 days than those at 22 days, indicating a possible resistance to colonization with increasing age. The findings emphasize the difficulties...... of establishing a reproducible model for infection with C. perfringens in broiler chickens....

  13. Cranberry juice and combinations of its organic acids are effective against experimental urinary tract infection

    DEFF Research Database (Denmark)

    Jensen, Heidi Dorthe; Struve, Carsten; Christensen, Søren Brøgger

    2017-01-01

    The antibacterial effect of cranberry juice and the organic acids therein on infection by uro28 pathogenic Escherichia coli was studied in an experimental mouse model of urinary tract infection (UTI). Reduced bacterial counts were found in the bladder (P ... juice. Commercially available cranberry juice cocktail also significantly reduced (P juice (P juice, were tested...... administered singly, did not have any effect in the UTI model. Apparently, the antibacterial effect of the organic acids from cranberry juice on UTI can be obtained by administering a combination of malic acid and either citric or quinic acid. This study show for the first time that cranberry juice reduce E...

  14. Experimental Infection of Snakes with Ophidiomyces ophiodiicola Causes Pathological Changes That Typify Snake Fungal Disease.

    Science.gov (United States)

    Lorch, Jeffrey M; Lankton, Julia; Werner, Katrien; Falendysz, Elizabeth A; McCurley, Kevin; Blehert, David S

    2015-11-17

    Snake fungal disease (SFD) is an emerging skin infection of wild snakes in eastern North America. The fungus Ophidiomyces ophiodiicola is frequently associated with the skin lesions that are characteristic of SFD, but a causal relationship between the fungus and the disease has not been established. We experimentally infected captive-bred corn snakes (Pantherophis guttatus) in the laboratory with pure cultures of O. ophiodiicola. All snakes in the infected group (n = 8) developed gross and microscopic lesions identical to those observed in wild snakes with SFD; snakes in the control group (n = 7) did not develop skin infections. Furthermore, the same strain of O. ophiodiicola used to inoculate snakes was recovered from lesions of all animals in the infected group, but no fungi were isolated from individuals in the control group. Monitoring progression of lesions throughout the experiment captured a range of presentations of SFD that have been described in wild snakes. The host response to the infection included marked recruitment of granulocytes to sites of fungal invasion, increased frequency of molting, and abnormal behaviors, such as anorexia and resting in conspicuous areas of enclosures. While these responses may help snakes to fight infection, they could also impact host fitness and may contribute to mortality in wild snakes with chronic O. ophiodiicola infection. This work provides a basis for understanding the pathogenicity of O. ophiodiicola and the ecology of SFD by using a model system that incorporates a host species that is easy to procure and maintain in the laboratory. Skin infections in snakes, referred to as snake fungal disease (SFD), have been reported with increasing frequency in wild snakes in the eastern United States. While most of these infections are associated with the fungus Ophidiomyces ophiodiicola, there has been no conclusive evidence to implicate this fungus as a primary pathogen. Furthermore, it is not understood why the

  15. The effectiveness of domestic cook on inactivation of murine norovirus in experimentally infected Manila clams (Ruditapes philippinarum).

    Science.gov (United States)

    Toffan, A; Brutti, A; De Pasquale, A; Cappellozza, E; Pascoli, F; Cigarini, M; Di Rocco, M; Terregino, C; Arcangeli, G

    2014-01-01

    The aim of this work was to evaluate the efficacy of domestic cooking in inactivating Manila clams experimentally infected with murine norovirus (MNV). A cooking pan was modified to enable electronic temperature probes to be positioned to record both flesh and environment temperature. Manila clams were infected with 10(4) TCID 50% ml(-1) of MNV. The infected whole-in-shell clams, divided into three replicates, were cooked on an electric stove, and groups of nine clams were removed from the pan at fixed intervals. Pools of three digestive glands were examined by virus isolation to ascertain residual viral load. Results showed that 10 min of cooking by a traditional domestic method at a temperature close to 100°C, for at least 2 min, can completely devitalize the MNV in infected clams. This is generally the time needed for the majority of valves to open up. At present, it is highly recommended to label all lagoon products as 'requiring cooking before consumption', but no specifications are given on how long and at what temperature they should be cooked. Our results can provide the consumer with useful indications on how to cook clams to prevent any risk of foodborne illness. © 2013 The Society for Applied Microbiology.

  16. Characterization of the porcine transferrin gene (TF) and its association with disease severity following an experimental Actinobacillus pleuropneumoniae infection.

    Science.gov (United States)

    Daniłowicz, E; Martinez-Arias, R; Dolf, G; Singh, M; Probst, I; Tümmler, B; Höltig, D; Waldmann, K-H; Gerlach, G-F; Stanke, F; Leeb, T

    2010-08-01

    Transferrin (TF)-mediated provision of iron is essential for a productive infection by many bacterial pathogens, and iron-depletion of TF is a first line defence against bacterial infections. Therefore, the transferrin (TF) gene can be considered a candidate gene for disease resistance. We obtained the complete DNA sequence of the porcine TF gene, which spans 40 kb and contains 17 exons. We identified polymorphisms on a panel of 10 different pig breeds. Comparative intra- and interbreed sequence analysis revealed 62 polymorphisms in the TF gene including one microsatellite. Ten polymorphisms were located in the coding sequence of the TF gene. Four SNPs (c.902A>T, c.980G>A, c.1417A>G, c.1810A>C) were predicted to cause amino acid exchanges (p.Lys301Ile, p.Arg327Lys, p.Lys473Glu, p.Asn604His). We performed association analyses using six selected TF markers and 116 pigs experimentally infected with Actinobacillus pleuropneumoniae serotype 7. The analysis showed breed-specific TF allele frequencies. In German Landrace, we found evidence for a possible association of the severity of A. pleuropneumoniae infection with TF genotypes.

  17. Studies on vertical transmission of Trichinella spiralis in experimentally infected guinea pigs (Cavia porcellus).

    Science.gov (United States)

    Riva, Eliana; Fiel, Cesar; Bernat, Gisele; Muchiut, Sebastián; Steffan, Pedro

    2017-08-01

    An experimental study to enhance knowledge on the capability of Trichenella spiralis to pass from guinea pigs to progeny at different periods of pregnancy or lactation was performed. For this purpose, 18 female adult guinea pigs were inoculated with 100 or 1000 T. spiralis muscle larvae (ML) during early, late gestation and during lactation period. The presence of T. spiralis (ML) in mothers and newborns was studied through enzymatic digestion from muscle samples. ML were observed in 9 of 42 newborn guinea pigs and levels of infection were significantly higher when infections of mothers were done during late gestation (p = 0.0046) with the high infective dose (p = 0.0043). T. spiralis ML were not recovered from any of the newborns from mothers infected in the lactation period. Ten out of 18 infected mothers presented larvae 1 in their mammary glands. Muscle samples from the tongue and the masseter showed the highest larval burdens. These observations confirm previous reports on that ML of T. spiralis are capable to pass through placental tissues to reach and encyst in striated muscle groups of newborn guinea pigs. This study may also reinforce the importance of preventive programs to control trichinellosis in those endemic areas where pregnant women would have high risk of infection.

  18. Expression of circulating leucocytes before, during and after myiasis by Dermatobia hominis in experimentally infected rats.

    Science.gov (United States)

    Gonçalves, Jomara M; Pereira, Mônica C T; Evangelista, Luciene G; Leite, Antônio C R

    2007-01-01

    Expression of circulating white blood cells was investigated in rats (Rattus norvegicus) experimentally infected with larvae of Dermatobia hominis, the human bot fly. Leucocytes were counted prior to infection (control group) as well as at 6, 10, 15, 20 and 28 days post-infection (dpi) and at 7, 15, 30 and 60 days post-larval emergence (dple). Total leucocyte numbers did not differ markedly among the groups. Significant differences were registered when values from control and animals harboring each larval stage of D. hominis were compared; with crescent rank: L1-, L2-, control and L3-infected groups. Leucocyte numbers were significantly higher in the control, 15, 20 or 28 dpi groups than in the 6 dpi animals. Higher counts were observed in control, L2- or L3-infected rats than L1-infected animals. Neutrophils, eosinophils and both large and small lymphocytes were also counted and analyzed. Basophils and monocytes were insufficient in number to permit statistical studies. These results stimulate the continuity of the studies about the host-parasite relationship in the dermatobiosis.

  19. The effect of salinity on experimental infections of a Hematodinium sp. in blue crabs, Callinectes sapidus.

    Science.gov (United States)

    Coffey, Anna H; Li, Caiwen; Shields, Jeffrey D

    2012-06-01

    The parasitic dinoflagellate Hematodinium sp. parasitizes blue crabs along the Atlantic seaboard of the United States. Infections in blue crabs have only been reported from waters where salinity is >11 practical salinity units (psu). Blue crabs maintain a hyperosmotic internal concentration at low salinities (0-5 psu), roughly comparable to 24 psu, and should be capable of maintaining an infection in low-salinity waters even if Hematodinium spp. cells are intolerant of low salinities. We tested this notion by observing the effect of low salinity on the progression of disease in crabs experimentally infected with the parasite. Blue crabs were acclimated to 5 psu or 30 psu salinity treatments. They were inoculated with Hematodinium sp. and necropsied 3, 7, 10, and 15 days post-inoculation. The low-salinity treatment did not have an effect on the proliferation of Hematodinium sp. infections in blue crabs; moreover, a greater proportion of infections in crabs in the low-salinity treatment developed dinospore stages than did those in the high-salinity treatment, indicating that salinity may affect the development of the parasite. However, dinospores from in vitro cultures rapidly became inactive when held in salinities <15 psu. Our experiments indicate that Hematodinium spp. can develop in blue crabs at low salinities, but that the parasite is incapable of transmission in this environment, which explains the lack of natural infections in crabs at low salinities.

  20. Destructive arthritis in a patient with chikungunya virus infection with persistent specific IgM antibodies

    Directory of Open Access Journals (Sweden)

    Receveur Marie-Catherine

    2009-12-01

    Full Text Available Abstract Background Chikungunya fever is an emerging arboviral disease characterized by an algo-eruptive syndrome, inflammatory polyarthralgias, or tenosynovitis that can last for months to years. Up to now, the pathophysiology of the chronic stage is poorly understood. Case presentation We report the first case of CHIKV infection with chronic associated rheumatism in a patient who developed progressive erosive arthritis with expression of inflammatory mediators and persistence of specific IgM antibodies over 24 months following infection. Conclusions Understanding the specific features of chikungunya virus as well as how the virus interacts with its host are essential for the prevention, treatment or cure of chikungunya disease.

  1. Experimental canine leishmaniasis: evolution of infection following re-challenge with Leishmania infantum.

    Science.gov (United States)

    Santos-Gomes, Gabriela M; Capela, Maria José Riça; Ramada, João; Campino, Lenea

    2003-07-01

    The aim of the study was to assess the clinical, parasitological and immunological effect of a second inoculation of amastigotes in dogs previously inoculated with Leishmania infantum. Three dogs primarily inoculated with amastigotes (Group I) and four with cultured virulent stationary phase promastigotes (Group II) were afterwards re-inoculated with 2x10(9) amastigotes per kg. Three other groups of dogs were used as controls: Group III was infected only once with amastigotes, Group IV only once with promastigotes and Group V was non infected. The animals were followed up by clinical and parasitological examinations, hematological and serum protein analysis, anti-leishmanial antibody levels and proliferative assays of specific peripheral blood mononuclear cells over a period up to 50 months. Parasites were isolated from lymph node of three animals during primary amastigote infection and in five animals (Group I and II) after re-challenge. Group I dogs presented a strong increase of the humoral immune response while Group II animals displayed no significant or significantly low antileishmanial antibodies titres, after re-challenge. The detection, only after challenge, of positive specific lymphoproliferation in two animals of Group II that had the longest primary infection interval (more than 26 months), indicates the requirement of a long time interval to obtain specific lymphocyte sensitization. A previous exposure to virulent cultured L. infantum promastigotes seems to confer some degree of resistance against an amastigote infection.

  2. Specific dietary oligosaccharides increase Th1 responses in a mouse respiratory syncytial virus infection model.

    Science.gov (United States)

    Schijf, Marcel A; Kruijsen, Debby; Bastiaans, Jacqueline; Coenjaerts, Frank E J; Garssen, Johan; van Bleek, Grada M; van't Land, Belinda

    2012-11-01

    Breast feeding reduces the risk of developing severe respiratory syncytial virus (RSV) infections in infants. In addition to maternal antibodies, other immune-modulating factors in human milk contribute to this protection. Specific dietary prebiotic oligosaccharides, similar to oligosaccharides present in human milk, were evaluated in a C57BL/6 mouse RSV infection model. During primary RSV infection, increased numbers of RSV-specific CD4(+) T cells producing gamma interferon (IFN-γ) were found in the lungs at days 8 to 10 postinfection in mice receiving diet containing short-chain galactooligosacharides, long-chain fructooligosaccharides, and pectin-derived acidic oligosaccharides (termed scGOS/lcFOS/pAOS). In a Th2-skewed formalin-inactivated (FI)-RSV vaccination model, the prebiotic diet reduced RSV-specific Th2 cytokine (interleukin-4 [IL-4], IL-5, and IL-13)-producing CD4(+) T cells in the lung and the magnitude of airway eosinophilia at day 4 and 6 after infection. This was accompanied by a decreased influx of inflammatory dendritic cells (CD11b(+)/CD11c(+)) and increased numbers of IFN-γ-producing CD4(+) and CD8(+) T cells at day 8 after viral challenge. These findings suggest that specific dietary oligosaccharides can influence trafficking and/or effector functions of innate immune, CD4(+), and CD8(+) T cell subsets in the lungs of RSV-infected mice. In our models, scGOS/lcFOS/pAOS had no effect on weight but increased viral clearance in FI-RSV-vaccinated mice 8 days after infection. The increased systemic Th1 responses potentiated by scGOS/lcFOS/pAOS might contribute to an accelerated Th1/Th2 shift of the neonatal immune system, which might favor protective immunity against viral infections with a high attack rate in early infancy, such as RSV.

  3. Exploring the limitations of pathophysiological indicators used for targeted selective treatment in sheep experimentally infected with Haemonchus contortus.

    Science.gov (United States)

    Chylinski, C; Cortet, J; Neveu, C; Cabaret, J

    2015-01-15

    Identifying which sheep to treat as part of a Targeted Selective Treatment approach to gastro-intestinal nematode control relies entirely on the efficacy of the indicators. Indicators such as FAMACHA© (anaemia), DISCO (diarrhea) and reductions in weight gains were designed specifically to reflect those sheep experiencing symptomatic consequences of infection. Using the gastro-intestinal nematode Haemonchus contortus as a model species, this study explored the utility and sensitivity of these indicators under controlled experimental conditions on 63 adult sheep. The potential effect of sheep with different H. contortus resistance phenotypes on indicator efficacy was compared in three different phenotypes, i.e. high (Blackbelly females), medium (Blackbelly rams) and low resistance (Romane rams). The potential effect of the H. contortus isolate on indicator efficacy was also explored by using four different isolates, with varying anthelmintic resistance capacities, to infect the sheep. We limited the study to the first month of infection to evaluate the interest of these indicators as an early predictive means for controlling infection. The pathophysiological indicators FAMACHA© and DISCO do not reflect infection intensity based on Faecal Egg Counts, nor do reductions in weight gains. FAMACHA© was however a good indicator of anaemia with strong correlations to haematocrit. There was little agreement among the three indicators to identify the same animals in need of treatment and even combining them did not increase their predictive value of infection intensity or relative host damage from infection. The indicator sensitivity was influenced by the H. contortus isolate and sheep resistance phenotype in which they were tested. One isolate was poorly infective but induced high levels of anaemia (FAMACHA©) and diarrhea (DISCO) compared to the three others. The FAMACHA© and DISCO had higher values in the sheep group with a medium resistance phenotype (Blackbelly rams

  4. Much Pain, Little Gain? Paradigm-Specific Models and Methods in Experimental Psychology.

    Science.gov (United States)

    Meiser, Thorsten

    2011-03-01

    Paradigm-oriented research strategies in experimental psychology have strengths and limitations. On the one hand, experimental paradigms play a crucial epistemic and heuristic role in basic psychological research. On the other hand, empirical research is often limited to the observed effects in a certain paradigm, and theoretical models are frequently tied to the particular features of the given paradigm. A paradigm-driven research strategy therefore jeopardizes the pursuit of research questions and theoretical models that go beyond a specific paradigm. As one example of a more integrative approach, recent research on illusory and spurious correlations has attempted to overcome the limitations of paradigm-specific models in the context of biased contingency perception and social stereotyping. Last but not least, the use of statistical models for the analysis of elementary cognitive functions is a means toward a more integrative terminology and theoretical perspective across different experimental paradigms and research domains. © The Author(s) 2011.

  5. Clinico-biochemical responses of dogs to experimental infection with Babesia canis

    Directory of Open Access Journals (Sweden)

    M. Konto

    2014-03-01

    Full Text Available Aim: A study on the clinical and biochemical parameters of Nigerian dogs experimentally infected with Babesia canis was conducted. Materials and Methods: A total of ten naive dogs of both sex and aged between 6 months to 1 year, were used for the study. They were divided into two groups of five each- A (control and B (infected. Dogs in group B were infected with 1ml of Babesia canis positive infectious inoculum, while those in group A were left as uninfected control. Following infection, clinical and biochemical responses were analyzed in group B and compared with those in group A. Results: Clinical signs were observed on the infected dogs 2 days post infection, which included fever (100%, increase in pulse (80%, tachycardia (60% and inappetence (100%; followed by anorexia (40% and lethargy (100% on day 3; on the fourth day, pallor of the mucous membrane of the mouth and eye (100% and emaciation (100%; on day five, muscle tremor (20% and respiratory distress (20%; on day six, nervousness (20%, drooling salivation (20% and haemoglobinuria (80; on day seven, mucoid ocular discharge (40%; followed by the death of one dog on day 8 post infection. Other clinical signs recorded between days 1-14 post infection were ascites, edematous swelling of the whole body and hair erection. The biochemical changes showed that there was a significant (p < 0.05 rise in alkaline phosphatase (ALP values in infected dogs (58.50±1.4 compared with the control group (51.67±1.6. Also, there was a significant rise (p < 0.05 in the alanine amino transferase (ALT values of infected group (15.70±1. 8 compared with the control values (8.27±2.0. However, the mean values for creatinine of infected group (78.10±1.2 was significantly lower (p < 0.05 than that of the control (91.73±1.3. Similarly, the glucose levels for infected group (3.80±2.3 were significantly (p < 0.05 lower than that of control (5.35±2.1. Conclusion: It can be concluded that the disease runs an acute

  6. Survival of Highly Pathogenic Avian Influenza H5N1 Virus in Tissues Derived from Experimentally Infected Chickens.

    Science.gov (United States)

    Yamamoto, Yu; Nakamura, Kikuyasu; Mase, Masaji

    2017-08-15

    Eurasian lineage highly pathogenic avian influenza (HPAI) H5N1 virus has been a severe threat to the poultry industry since its emergence in 1996. The carcass or tissues derived from infected birds may present the risk of the virus spreading to humans, animals, and the surrounding environment. In this study, we investigated the survival of the virus in feather, muscle, and liver tissues collected from six chickens (Gallus gallus) experimentally infected with HPAI H5N1 virus. The tissues were stored at +4°C or +20°C, and viral isolation was performed at different times for 360 days. The maximum periods for viral survival were observed in samples stored at +4°C in all tissue types and were 240 days in feather tissues, 160 days in muscle, and 20 days in liver. The viral infectivity at +20°C was maintained for a maximum of 30 days in the feather tissues, 20 days in muscle, and 3 days in liver. The viral inactivation rates partly overlapped in the feather and muscle tissues at the two temperatures. The virus was inactivated rapidly in the liver. Our experimental results indicate that the tissue type and temperature can greatly influence the survival of HPAI H5N1 virus in the tissues of infected chickens.IMPORTANCE Highly pathogenic avian influenza virus of the H5N1 subtype can cause massive losses of poultry, and people need to handle a large number of chicken carcasses contaminated with the virus at outbreak sites. This study evaluated how long the virus can keep its infectivity in the three types of tissues derived from chickens infected with the virus. Our experimental results indicate that the virus can survive in tissues for a specific period of time depending on the tissue type and temperature. Our results are valuable for better understanding of viral ecology in the environment and for reducing the risk of the virus spreading via bird tissues contaminated with the virus. Copyright © 2017 American Society for Microbiology.

  7. Experimental Infection of Pig-Tailed Macaques (Macaca nemestrina) with Mycoplasma genitalium

    Science.gov (United States)

    Wood, Gwendolyn E.; Patton, Dorothy L.; Cummings, Peter K.; Iverson-Cabral, Stefanie L.

    2016-01-01

    ABSTRACT Mycoplasma genitalium is an underappreciated cause of human reproductive tract disease, characterized by persistent, often asymptomatic, infection. Building on our previous experiments using a single female pig-tailed macaque as a model for M. genitalium infection (G. E. Wood, S. L. Iverson-Cabral, D. L. Patton, P. K. Cummings, Y. T. Cosgrove Sweeney, and P. A. Totten, Infect Immun 81:2938–2951, 2013, https://doi.org/10.1128/IAI.01322-12), we cervically inoculated eight additional animals, two of which were simultaneously inoculated in salpingeal tissue autotransplanted into abdominal pockets. Viable M. genitalium persisted in the lower genital tract for 8 weeks in three animals, 4 weeks in two, and 1 week in one; two primates resisted infection. In both animals inoculated in salpingeal pockets, viable M. genitalium was recovered for 2 weeks. Recovery of viable M. genitalium from lower genital tract specimens was improved by diluting the specimen in broth and by Vero cell coculture. Ascension to upper reproductive tract tissues was not detected, even among three persistently infected animals. M. genitalium-specific serum antibodies targeting the immunodominant MgpB and MgpC proteins appeared within 1 week in three animals inoculated both cervically and in salpingeal pockets and in one of three persistently infected animals inoculated only in the cervix. M. genitalium-specific IgG, but not IgA, was detected in cervical secretions of serum antibody-positive animals, predominantly against MgpB and MgpC, but was insufficient to clear M. genitalium lower tract infection. Our findings further support female pig-tailed macaques as a model of M. genitalium infection, persistence, and immune evasion. PMID:27872239

  8. Marginal vitamin A deficiency in pigs experimentally infected with Trichuris suis

    DEFF Research Database (Denmark)

    Pedersen, S; Saeed, I; Jensen, S K

    2001-01-01

    The development of an experimental model for marginal vitamin A deficiency in humans is of major interest, enabling the elucidation of possible interactions with helminth infections. We established a useful experimental model for human vitamin A deficiency in young pigs; deficiency was induced...... through a depletion method encompassing both sow and offspring. We report on a 2 x 2 study in which 18-week-old vitamin A deficient pigs and vitamin A sufficient littermates were infected with both of the intestinal nematodes Trichuris suis and Ascaris suum and followed for 14 weeks through 32 weeks...... of age. Forty-nine pigs were followed with respect to bodyweight, liver biopsies and blood samples for retinol concentration and faecal samples for parasite eggs and worms. Liver and serum concentrations of vitamin A were significantly diminished in the vitamin A deficient (VAD) group as compared...

  9. Anatomopathological study in BALB/c mice brains experimentally infected with Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Marcos Gontijo da Silva

    Full Text Available Toxoplasmosis is one of the most important diseases of the nervous central system, leading to severe symptoms and, many times, irreversible sequelae. This work demonstrated the main anatomopathological lesions caused by Toxoplasma gondii in brains from experimentally infected BALB/c mice. We analyzed 51 cases of mice that developed toxoplasmosis after experimental infection by intraperitoneal inoculation of blood, amniotic liquid and cerebrospinal fluid from fetuses, newly born children and pregnant women with clinical and laboratory signals of toxoplasmosis. In all experiments where we detected the parasite in mice we also detected pathological lesions in the animal brains with great polymorphism between experiments. Edema was the most found lesion in all cases. Besides, it was possible to demonstrate the inflammatory process in 82.4% of cases and necrosis in 64.7% of cases, in agreement with the literature that describes severe neurological damage in its hosts.

  10. Experimental infection of snakes with Ophidiomyces ophiodiicola causes pathological changes that typify snake fungal disease

    Science.gov (United States)

    Lorch, Jeffrey M.; Lankton, Julia S.; Werner, Katrien; Falendysz, Elizabeth A.; McCurley, Kevin; Blehert, David S.

    2015-01-01

    Snake fungal disease (SFD) is an emerging skin infection of wild snakes in eastern North America. The fungus Ophidiomyces ophiodiicola is frequently associated with the skin lesions that are characteristic of SFD, but a causal relationship between the fungus and the disease has not been established. We experimentally infected captive-bred corn snakes (Pantherophis guttatus) in the laboratory with pure cultures of O. ophiodiicola. All snakes in the infected group (n = 8) developed gross and microscopic lesions identical to those observed in wild snakes with SFD; snakes in the control group (n = 7) did not develop skin infections. Furthermore, the same strain of O. ophiodiicola used to inoculate snakes was recovered from lesions of all animals in the infected group, but no fungi were isolated from individuals in the control group. Monitoring progression of lesions throughout the experiment captured a range of presentations of SFD that have been described in wild snakes. The host response to the infection included marked recruitment of granulocytes to sites of fungal invasion, increased frequency of molting, and abnormal behaviors, such as anorexia and resting in conspicuous areas of enclosures. While these responses may help snakes to fight infection, they could also impact host fitness and may contribute to mortality in wild snakes with chronic O. ophiodiicola infection. This work provides a basis for understanding the pathogenicity of O. ophiodiicola and the ecology of SFD by using a model system that incorporates a host species that is easy to procure and maintain in the laboratory.

  11. Metabolic and histopathological profile of Rattus norvegicus (Wistar) experimentally infected by Angiostrongylus cantonensis (Chen, 1935).

    Science.gov (United States)

    Garcia, Juberlan Silva; Lúcio, Camila dos Santos; Bonfim, Tatiane Cristina dos Santos; Junior, Arnaldo Maldonado; Tunholi, Victor Menezes; Tunholi-Alves, Vinícius Menezes; Mota, Esther Maria; Simões, Raquel de Oliveira; Santana, André Campos; Hooper, Cleber; Pinheiro, Jairo; Bóia, Marcio Neves

    2014-02-01

    Eosinophilic meningitis is a disease characterized by increased eosinophils in the cerebrospinal fluid (CSF), which is the most commonly caused by invasion of the central nervous system by helminths, as occurs in Angiostrongylus cantonensis infections. The rodent Rattus norvegicus is the definitive natural host and humans act as accidental hosts and can become infected by eating raw or undercooked snails or food contaminated with infective L3 larvae. Recently in Brazil there have been four cases of eosinophilic meningitis due to ingestion of infected Achatina fulica. To evaluate biochemical and histopathological changes caused by this parasite, R. norvegicus were experimentally infected with 100 L3 larvae of A. cantonensis. After the anesthetic procedure, serum from the rodents was collected from the inferior vena cava for evaluation of the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALKP), gamma-glutamyl transferase (GGT), total protein and its fractions. During the necropsy, the liver was collected and weighed. Then a 1-g fragment was extracted from the major lobe to quantify the hepatic glycogen and fragment remainder was taken from the same lobe and fixed in Milloning's formalin for histopathological examination. Additionally, helminths were collected from the brain and lungs of the rodents. The activities of AST, ALT, ALKP and GGT in the serum and hepatic glycogen increased in response to infection, while the levels of globulin and total protein increased only in the eighth week of infection and there was a reduction in the levels of serum glucose. Albumin and bilirubin concentrations remained stable during the experiment. Infection with A. cantonensis caused metabolic and histopathological changes in the rodents. This study can contribute to a better understanding of the relationship between A. cantonensis and R. norvegicus. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Excretion of (3H)prednisolone in clinically normal and experimentally infected bovine udders

    Energy Technology Data Exchange (ETDEWEB)

    Geleta, J.N.; Shimoda, W.; Mercer, H.D.

    1984-08-01

    The excretion rate of (3H)prednisolone from clinically normal and experimentally infected udders of 10 lactating cows was studied. Each quarter of 6 cows was injected with a single dose of (3H)prednisolone mixed with non-radioactive prednisolone equivalent to 10 mg in 10 ml of peanut oil base. Each of the remaining 4 cows was given 40 mg of nonradioactive prednisolone and (3H)prednisolone in 60% ethanol IV. Control and postadministration samples of blood, milk, and urine were examined for radioactivity. The effects of (3H)prednisolone were evaluated in the same cows, first in clinically normal udders, then 2 weeks later in udders experimentally infected with Streptococcus agalactiae. Absorption and elimination of prednisolone were the same before and after induced infection. Within 3 hours after intramammary injection, 95% of the labeled prednisolone was absorbed systemically, less than 5% of this dose was recovered in milk, and 29% was excreted in urine. After IV injection of (3H)prednisolone, less than 0.2% of the total radioactivity was recovered in milk and less than 46% was excreted in urine. Clinical mastitis induced by S agalactiae was moderate. Circulating blood leukocytes and somatic cells in the milk of normal cows remained essentially unchanged. The leukocyte response to induced infection was rapid in blood and milk. Large numbers of leukocytes were noticed in the milk and a severe leukopenia occurred. Prednisolone treatment did not alter the number of somatic cells in milk or reduce the inflammatory response of experimentally infected cows.

  13. Excretion of [3H]prednisolone in clinically normal and experimentally infected bovine udders.

    Science.gov (United States)

    Geleta, J N; Shimoda, W; Mercer, H D

    1984-08-01

    The excretion rate of [3H]prednisolone from clinically normal and experimentally infected udders of 10 lactating cows was studied. Each quarter of 6 cows was injected with a single dose of [3H]prednisolone mixed with non-radioactive prednisolone equivalent to 10 mg in 10 ml of peanut oil base. Each of the remaining 4 cows was given 40 mg of nonradioactive prednisolone and [3H]prednisolone in 60% ethanol IV. Control and postadministration samples of blood, milk, and urine were examined for radioactivity. The effects of [3H]prednisolone were evaluated in the same cows, first in clinically normal udders, then 2 weeks later in udders experimentally infected with Streptococcus agalactiae. Absorption and elimination of prednisolone were the same before and after induced infection. Within 3 hours after intramammary injection, 95% of the labeled prednisolone was absorbed systemically, less than 5% of this dose was recovered in milk, and 29% was excreted in urine. After IV injection of [3H]prednisolone, less than 0.2% of the total radioactivity was recovered in milk and less than 46% was excreted in urine. Clinical mastitis induced by S agalactiae was moderate. Circulating blood leukocytes and somatic cells in the milk of normal cows remained essentially unchanged. The leukocyte response to induced infection was rapid in blood and milk. Large numbers of leukocytes were noticed in the milk and a severe leukopenia occurred. Prednisolone treatment did not alter the number of somatic cells in milk or reduce the inflammatory response of experimentally infected cows.

  14. Tissue-specific interferon alpha subtype response to SIV infection in brain, spleen, and lung.

    Science.gov (United States)

    Zaritsky, Luna Alammar; Dery, Alicia; Leong, Wan Yee; Gama, Lucio; Clements, Janice E

    2013-01-01

    Interferon alpha (IFNalpha) is a type I interferon that plays a major role in host defense. There are 13 different IFNalpha genes in humans, but much of the work concerning their role in viral defense has been limited to studying either subtype 2 or pan IFNalpha due to the inability to distinguish between highly similar genetic and amino acid sequences. Because of recent advances in molecular and biochemical techniques, it is possible to study the regulation of individual subtypes. It has been reported that HIV/SIV infection results in impaired IFNalpha responses in certain tissues. Using a pigtailed macaque SIV model, we examined the subtype response during acute infection in 3 tissues that are known to be infected with HIV/SIV, but whose IFNalpha subtype response has not been extensively studied: the brain, spleen, and lung. We found that the expression and regulation of specific subtypes occur in a tissue-specific manner. There was more limited IFNalpha subtype expression in the lung and brain, where predominantly macrophages are infected compared to the spleen, which contains both infected CD4+ lymphocytes and macrophages. Understanding the IFNalpha subtype response in tissues known to be infected with HIV/SIV can help tailor adjunctive treatment regimens to highly active antiretroviral therapy.

  15. Population dynamics of the minute intestinal trematode Haplorchis pumilio following experimental infection of young dogs

    DEFF Research Database (Denmark)

    Nissen, Sofie; Nguyen, Lan Anh; Thamsborg, Stig Milan

    2011-01-01

    to have the highest intensity of infection and contribute the most to the contamination of the environment with FZT eggs in the Nam Dinh province - a highly endemic area for FZTs. Given the free roaming and fish-eating behaviour of many dogs in rural Vietnam controlling the infection in dogs represents......Fishborne zoonotic trematodes (FZT) are highly prevalent in Southeast Asia. Recent studies on domestic animal’s role in the transmission of FZT in Northern Vietnam found that the most prevalent FZT was Haplorchis pumilio. The importance of dogs, cats and pigs was assessed, and dogs were found...... a major challenge. In particular knowledge is needed on the importance of the dog as reservoir to make evidence-based recommendations for control of FZT. On this background, we conducted an experimental infection in dogs with H. pumilio to elucidate population dynamics and host reactions. Eight household...

  16. Nutritional Status Driving Infection by Trypanosoma cruzi: Lessons from Experimental Animals

    Directory of Open Access Journals (Sweden)

    Guilherme Malafaia

    2011-01-01

    Full Text Available This paper reviews the scientific knowledge about protein-energy and micronutrient malnutrition in the context of Chagas disease, especially in experimental models. The search of articles was conducted using the electronic databases of SciELO (Scientific Electronic Library Online, PubMed and MEDLINE published between 1960 and March 2010. It was possible to verify that nutritional deficiencies (protein-energy malnutrition and micronutrient malnutrition exert a direct effect on the infection by T. cruzi. However, little is known about the immunological mechanisms involved in the relationship “nutritional deficiencies and infection by T. cruzi”. A hundred years after the discovery of Chagas disease many aspects of this illness still require clarification, including the effects of nutritional deficiencies on immune and pathological mechanisms of T. cruzi infection.

  17. Therapy of the experimental infection by Strongyloides venezuelensis in rats with injectable ivermectin or levamizole

    Directory of Open Access Journals (Sweden)

    Rubens Campos

    1989-02-01

    Full Text Available For the therapy of human strongyloidiasis, are necessary effective drugs to eliminate both larvae and adult worm parasitism, which may also be used by parenteral route, to obviate the particular conditions presented by many patients. A study based on the experimental infection by Strongyloides venezuelensis in rats was done, administering injectable ivermectin or levamizole. Both drugs were shown to be active, when used in single doses of 0.2 to 0.5 mg/kg of ivermectin, or 26 mg/kg for levamizole. Ivermectin was slightly more effective as far as larval stage of the infection is concerned, and the same happened for levamisole for the adult worm stage. Promising perspectives are visualized to improve the therapy of patients with serious disseminated infection by Strongyloides stercoralis.

  18. Type-specific cervico-vaginal human papillomavirus infection increases risk of HIV acquisition independent of other sexually transmitted infections.

    Directory of Open Access Journals (Sweden)

    Karen K Smith-McCune

    2010-04-01

    Full Text Available Sexually transmitted infections (STIs such as herpes simplex virus (HSV-2 are associated with an increased risk of HIV infection. Human papillomavirus (HPV is a common STI, but little is know about its role in HIV transmission. The objective of this study was to determine whether cervico-vaginal HPV infection increases the risk of HIV acquisition in women independent of other common STIs.This prospective cohort study followed 2040 HIV-negative Zimbabwean women (average age 27 years, range 18-49 years for a median of 21 months. Participants were tested quarterly for 29 HPV types (with L1 PCR primers and HIV (antibody testing on blood samples with DNA or RNA PCR confirmation. HIV incidence was 2.7 per 100 woman-years. Baseline HPV prevalence was 24.5%, and the most prevalent HPV types were 58 (5.0%, 16 (4.7%, 70 (2.4%, and 18 (2.3%. In separate regression models adjusting for baseline variables (including age, high risk partner, positive test for STIs, positive HSV-2 serology and condom use, HIV acquisition was associated with having baseline prevalent infection with HPV 58 (aHR 2.13; 95% CI 1.09-4.15 or HPV 70 (aHR 2.68; 95% CI 1.08-6.66. In separate regression models adjusting for both baseline variables and time-dependent variables (including HSV-2 status, incident STIs, new sexual partner and condom use, HIV acquisition was associated with concurrent infection with any non-oncogenic HPV type (aHR 1.70; 95% CI 1.02-2.85, any oncogenic HPV type (aHR 1.96; 95% CI 1.16-3.30, HPV 31 (aHR 4.25; 95% CI 1.81-9.97 or HPV 70 (aHR 3.30; 95% CI 1.50-7.20. Detection of any oncogenic HPV type within the previous 6 months was an independent predictor of HIV acquisition, regardless of whether HPV status at the HIV acquisition visit was included (aHR 1.95; 95% CI 1.19-3.21 or excluded (aHR 1.96; 95% CI 1.02-2.85 from the analysis.Cervico-vaginal HPV infection was associated with an increased risk of HIV acquisition in women, and specific HPV types were

  19. The Healing Effect of Licorice on Pseudomonas aeruginosa Infected Burn Wounds in Experimental Rat Model

    OpenAIRE

    Tanideh, Nader; Rokhsari, Pedram; Mehrabani, Davood; Mohammadi Samani, Soleiman; Sabet Sarvestani, Fatemeh; Ashraf, Mohammad Javad; Koohi Hosseinabadi, Omid; Shamsian, Shahram; AHMADI, Nasrollah

    2014-01-01

    BACKGROUND Burn is still one of the most devastating injuries in emergency medicine while improvements in wound healing knowledge and technology have resulted into development of new dressings. This study was undertaken to evaluate the healing effect of licorice in Pseudomonas aeruginosa infected burn wounds of experimental rat model. METHODS One hundred and twenty female Sprague-Dawley rats were randomly allocated to 4 equal groups. Group A received silver sulfadiazine ointment, Group B rece...

  20. Effect of resinous extract from Commiphora swynnertonii (Burrt) on experimental coccidial infection in chickens.

    Science.gov (United States)

    Bakari, Gaymary G; Max, Robert A; Mdegela, Robinson H; Phiri, Elliot C J; Mtambo, Mkumbukwa M A

    2013-02-01

    A crude resinous extract from Commiphora swynnertonii was tested against an experimental coccidial infection in local chickens. A total of 80 growing chickens were randomly assigned into five groups, which received different treatments. Chickens in G1 were not infected with coccidian oocysts and therefore served as a negative control. All chickens in G2, G3, G4 and G5 were infected through oral administration of coccidian oocysts suspension at a dosed rate of 1.5 × 10(4) Eimeria spp. oocysts per bird. Starting from day 3 post-infection (p.i), chickens in different groups were treated for 7 consecutive days as follows: G1 and G2 (positive control) received 5 ml of normal saline as placebo, G3 and G4 were given the extract at 400 and 800 mg/kg bodyweight whereas G5 received anticoccidial drug. Clinical signs, bodyweights, oocysts counts and mortality rates were observed regularly. Results showed that oral administration of the resinous extract to chickens with coccidiosis significantly reduced mortality rate from 94 to 25 % and oocysts counts from 1.03 × 10(5) to 6.55 × 10(3) oocysts/g faeces (p < 0.05). Also a body condition score chart indicated less severe clinical signs of the disease in the groups which received the extract. Mean daily body weights were slightly reduced by the administration of the extract but this effect disappeared by day 7 p.i. These findings clearly indicate that resinous extract from C. swynnertonii has significant anticoccidial effect against experimental Eimeria spp. infection in chickens. A larger field trial to validate the use of the extract in chickens naturally infected with Eimeria spp. is required.

  1. Semen variables of sheep (Ovis aries) experimentally infected with Toxoplasma gondii.

    Science.gov (United States)

    Lopes, W D Z; Costa, A J; Souza, F A; Rodrigues, J D F; Costa, G H N; Soares, V E; Silva, G S

    2009-04-01

    The influence of Toxoplasma gondii on semen variables and sperm morphology of sheep was evaluated in eight reproductive males distributed into three experimental groups: GI, three sheep inoculated with 2.0x10(5) of P strain oocytes; GII, three sheep infected with 1.0x10(6) of RH strain tachyzoites and; GIII two control sheep. Clinical (rectal temperature, cardiac and respiratory frequencies), parasite and serology exams (IIF) were realized. Sperm variables (volume, motility, vigor and concentration) and semen morphology for each sheep were also evaluated. Thus, semen and blood collections were assessed on post-inoculation days (PIDs)-1,3,5,7,11,14 and weekly thereafter up to PID 70. Clinical alterations were observed (hypothermia and anorexia) in infected sheep from groups GI and GII. Parasitic outbreaks were detected in five sheep. All the infected sheep produced antibodies against T. gondii from PID 5 onwards, reaching a peak of 4096 and 8192 for group GI and GII sheep, respectively. Differences (P<0.05) were observed regarding the ejaculate volume between the inoculated groups (oocytes and tachyzoites) and control. Even though experimental toxoplasmic infection resulted in clinical symptomology in the inoculated sheep, the minimal alterations in sperm pathologies could not be directly attributed to T. gondii.

  2. Protein profile of lambs experimentally infected with Haemonchus contortus and supplemented with selenium and copper.

    Science.gov (United States)

    Fausto, Guilherme Costa; Pivoto, Felipe Lamberti; Costa, Márcio Machado; dos Anjos Lopes, Sônia Terezinha; França, Raqueli Teresinha; Molento, Marcelo Beltrão; Minervino, Antonio Humberto Hamad; da Rocha, João Batista Teixeira; Leal, Marta Lizandra do Rêgo

    2014-08-05

    Gastrointestinal nematodes cause significant economic losses in the sheep industry, with frequent reports of anthelmintic resistance. Therefore, alternative methods to control these parasites are necessary. Thus, the aim of the present study was to assess the effect of treatment with selenium and copper on the protein profile of sheep that were experimentally infected with Haemonchus contortus. Twenty-eight lambs were experimentally infected with H. contortus and divided into four experimental groups as follow: G1--untreated animals; G2--treated with sodium selenite; G3--treated with copper; G4--treated with sodium selenite and copper. The serum protein, body weight and egg count per gram of feces (EPG) were assessed at the baseline and after 20, 40, 60 and 80 days. The parasite burden was assessed 80 days after the beginning of the experiment. Higher levels of total protein and gamma globulin were observed in the lambs treated with sodium selenite and copper on D80. Copper acted as a growth promoter. The copper-supplemented groups exhibited higher daily and total weight gain. The association of selenium and copper altered the protein profile of sheep. Copper and selenium supplementation reduced EPG and worm burden at the end of the experiment. To the best of our knowledge, this is the first study to demonstrate the positive effect of the combined parenteral supplementation of Se and Cu on H. contortus infection. This injectable supplementation could be used as an auxiliary method to control H. contortus in sheep.

  3. Adoptive transfer of EBV specific CD8+ T cell clones can transiently control EBV infection in humanized mice

    National Research Council Canada - National Science Library

    Antsiferova, Olga; Müller, Anne; Rämer, Patrick C; Chijioke, Obinna; Chatterjee, Bithi; Raykova, Ana; Planas, Raquel; Sospedra, Mireia; Shumilov, Anatoliy; Tsai, Ming-Han; Delecluse, Henri-Jacques; Münz, Christian

    2014-01-01

    Epstein Barr virus (EBV) infection expands CD8+ T cells specific for lytic antigens to high frequencies during symptomatic primary infection, and maintains these at significant numbers during persistence...

  4. Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection

    DEFF Research Database (Denmark)

    Brock, I; Weldingh, K; Leyten, EM

    2004-01-01

    Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection.Brock I, Weldingh K, Leyten EM, Arend SM, Ravn P, Andersen P. Department of Infectious Disease Immunology, Statens Serum Institute, Artillerivej 5, DK-2300 Copenhagen S, Denmark. The currently used...... method for immunological detection of tuberculosis infection, the tuberculin skin test, has low specificity. Antigens specific for Mycobacterium tuberculosis to replace purified protein derivative are therefore urgently needed. We have performed a rigorous assessment of the diagnostic potential of four...... recently identified antigens (Rv2653, Rv2654, Rv3873, and Rv3878) from genomic regions that are lacking from the Mycobacterium bovis bacillus Calmette-Guerin (BCG) vaccine strains as well as from the most common nontuberculous mycobacteria. The fine specificity of potential epitopes in these molecules...

  5. Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection

    DEFF Research Database (Denmark)

    Brock, I; Weldingh, K; Leyten, EM

    2004-01-01

    Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection.Brock I, Weldingh K, Leyten EM, Arend SM, Ravn P, Andersen P. Department of Infectious Disease Immunology, Statens Serum Institute, Artillerivej 5, DK-2300 Copenhagen S, Denmark. The currently used...... method for immunological detection of tuberculosis infection, the tuberculin skin test, has low specificity. Antigens specific for Mycobacterium tuberculosis to replace purified protein derivative are therefore urgently needed. We have performed a rigorous assessment of the diagnostic potential of four...... selected and combined the specific peptide stretches from the four proteins not recognized by M. bovis BCG-vaccinated individuals. These peptide stretches were tested with peripheral blood mononuclear cells obtained from patients with microscopy- or culture-confirmed tuberculosis and from healthy M. bovis...

  6. Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection

    DEFF Research Database (Denmark)

    Brock, I; Weldingh, K; Leyten, EM

    2004-01-01

    recently identified antigens (Rv2653, Rv2654, Rv3873, and Rv3878) from genomic regions that are lacking from the Mycobacterium bovis bacillus Calmette-Guerin (BCG) vaccine strains as well as from the most common nontuberculous mycobacteria. The fine specificity of potential epitopes in these molecules......Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection.Brock I, Weldingh K, Leyten EM, Arend SM, Ravn P, Andersen P. Department of Infectious Disease Immunology, Statens Serum Institute, Artillerivej 5, DK-2300 Copenhagen S, Denmark. The currently used...... method for immunological detection of tuberculosis infection, the tuberculin skin test, has low specificity. Antigens specific for Mycobacterium tuberculosis to replace purified protein derivative are therefore urgently needed. We have performed a rigorous assessment of the diagnostic potential of four...

  7. Virus-Specific Cytotoxic T Lymphocytes in Human Immunodeficiency Virus Type 1-Infected Chimpanzees

    OpenAIRE

    Santra, Sampa; Fultz, Patricia N.; Letvin, Norman L.

    1999-01-01

    Chimpanzees have been important in studies of human immunodeficiency virus type 1 (HIV-1) pathogenesis and in evaluation of HIV-1 candidate vaccines. However, little information is available about HIV-1-specific cytotoxic T lymphocytes (CTL) in these animals. In the present study, in vitro stimulation of peripheral blood mononuclear cells (PBMC) from infected chimpanzees with HIV-1 Gag peptides was shown to be a sensitive, reproducible method of expanding HIV-1-specific CD8+ effector CTL. Of ...

  8. Prolonged activation of virus-specific CD8+T cells after acute B19 infection.

    Directory of Open Access Journals (Sweden)

    Adiba Isa

    2005-12-01

    Full Text Available Human parvovirus B19 (B19 is a ubiquitous and clinically significant pathogen, causing erythema infectiosum, arthropathy, transient aplastic crisis, and intrauterine fetal death. The phenotype of CD8+ T cells in acute B19 infection has not been studied previously.The number and phenotype of B19-specific CD8+ T cell responses during and after acute adult infection was studied using HLA-peptide multimeric complexes. Surprisingly, these responses increased in magnitude over the first year post-infection despite resolution of clinical symptoms and control of viraemia, with T cell populations specific for individual epitopes comprising up to 4% of CD8+ T cells. B19-specific T cells developed and maintained an activated CD38+ phenotype, with strong expression of perforin and CD57 and downregulation of CD28 and CD27. These cells possessed strong effector function and intact proliferative capacity. Individuals tested many years after infection exhibited lower frequencies of B19-specific cytotoxic T lymphocytes, typically 0.05%-0.5% of CD8+ T cells, which were perforin, CD38, and CCR7 low.This is the first example to our knowledge of an "acute" human viral infection inducing a persistent activated CD8+ T cell response. The likely explanation--analogous to that for cytomegalovirus infection--is that this persistent response is due to low-level antigen exposure. CD8+ T cells may contribute to the long-term control of this significant pathogen and should be considered during vaccine development.

  9. Prolonged activation of virus-specific CD8+T cells after acute B19 infection.

    Directory of Open Access Journals (Sweden)

    2005-12-01

    Full Text Available BACKGROUND: Human parvovirus B19 (B19 is a ubiquitous and clinically significant pathogen, causing erythema infectiosum, arthropathy, transient aplastic crisis, and intrauterine fetal death. The phenotype of CD8+ T cells in acute B19 infection has not been studied previously. METHODS AND FINDINGS: The number and phenotype of B19-specific CD8+ T cell responses during and after acute adult infection was studied using HLA-peptide multimeric complexes. Surprisingly, these responses increased in magnitude over the first year post-infection despite resolution of clinical symptoms and control of viraemia, with T cell populations specific for individual epitopes comprising up to 4% of CD8+ T cells. B19-specific T cells developed and maintained an activated CD38+ phenotype, with strong expression of perforin and CD57 and downregulation of CD28 and CD27. These cells possessed strong effector function and intact proliferative capacity. Individuals tested many years after infection exhibited lower frequencies of B19-specific cytotoxic T lymphocytes, typically 0.05%-0.5% of CD8+ T cells, which were perforin, CD38, and CCR7 low. CONCLUSION: This is the first example to our knowledge of an "acute" human viral infection inducing a persistent activated CD8+ T cell response. The likely explanation--analogous to that for cytomegalovirus infection--is that this persistent response is due to low-level antigen exposure. CD8+ T cells may contribute to the long-term control of this significant pathogen and should be considered during vaccine development.

  10. Specific immunoglobulin measurements related to exposure and resistance to Schistosoma mansoni infection in Sudanese canal cleaners

    DEFF Research Database (Denmark)

    Satti, M.Z.; Lind, Peter; Vennervald, B.J.

    1996-01-01

    was used to detect specific IgE and IgG subclasses in response to whole worm antigen (WWH) and soluble egg antigen (SEA) before and 3 months after praziquantel treatment in the groups of canal cleaners and before and 1 year after treatment in normally exposed adults. When intensity of infection...

  11. Immuno PET/MR imaging allows specific detection of Aspergillus fumigatus lung infection in vivo

    DEFF Research Database (Denmark)

    Rolle, Anna-Maria; Hasenberg, Mike; Thornton, Christopher R.

    2016-01-01

    a novel probe for noninvasive detection of A. fumigatus lung infection based on antibody-guided positron emission tomography and magnetic resonance (immunoPET/MR) imaging.Administration of a [64Cu]DOTA-labeled A. fumigatus-specific monoclonal antibody (mAb), JF5, to neutrophil-depleted A. fumigatus...

  12. Limited Specificity in the Injury and Infection Priming against Bacteria in Aedes aegypti Mosquitoes

    Science.gov (United States)

    Vargas, Valeria; Moreno-García, Miguel; Duarte-Elguea, Erika; Lanz-Mendoza, Humberto

    2016-01-01

    Injury and infection priming has been observed in several insect groups, reported as host immune protection against contact with a pathogen caused by a previous infection with the same. However, the specific response against a pathogen has not been demonstrated in all insect species. Investigating the specific priming response in insects is important because their immune strategies probably reflect particular selective pressures exerted by different pathogens. Here, we determined whether previous infection of Aedes aegypti would enhance survival and/or lead to greater and specific AMP expression after a second exposure to the same or a distinct bacterium. Mosquitoes previously immunized with a low dose of Escherichia coli, but not Staphylococcus aureus, showed increased survival. Although the host protection herein demonstrated was not specific, each bacterium elicited differential AMP expression. These results can be explained by the susceptible-primed-infected (SPI) epidemiological model, which poses that in the evolution of memory-like responses (priming), a pivotal role is played by pathogen virulence, associated host damage, and the host capacity of pathogen recognition. PMID:27446016

  13. Effects of atmospheric ammonia on young pigs experimentally infected with Ascaris suum

    Energy Technology Data Exchange (ETDEWEB)

    Drummond, J.G.; Curtis, S.E.; Simon, J.; Norton, H.W.

    1981-06-01

    Effects of atmospheric ammonia at 69.4 mg/m3 (100 ppm) on productive performance and respiratory tract health of young pigs (starting body weight averaged 7.5 kg) experimentally infected with Ascaris suum (50,000 embryonated ova administered by gavage when pigs were 5 weeks of age) were studied in 5 trials of 4 weeks each (when pigs were 5 to 9 weeks of age). Effects of atmospheric-ammonia exposure and ascarid infection on growth were additive. Compared with controls, percentage reductions in average daily gain were 32%, 28%, and 61% for ammonia-exposed, ascarid-infected, and combined ammonia plus ascarid groups, respectively. Ammonia exposure or ascarid infection alone depressed feed disappearance by 18%. Effects of the 2 factors were additive, resulting in a 35% reduction in feed disappearance. Pigs exposed to the combined factors had an average gain/feed ratio of 0.518, which was less than that of control pigs (0.546), but was greater than that of pigs exposed to atmospheric ammonia (0.489) or pigs infected with ascarids (0.501) alone. Liver scarring, due to larval migration, was not affected by ammonia exposure. Larval migration through the respiratory tract was not confirmed histopathologically in pigs killed 4 weeks after inoculation. A supplementary experiment was conducted which demonstrated that residual evidence of previous pulmonary larval migration was present 2 weeks after inoculation.

  14. Mucosal Immune Responses of Mice Experimentally Infected with Pygidiopsis summa (Trematoda: Heterophyidae)

    Science.gov (United States)

    Chai, Jong-Yil; Park, Young-Jin; Park, Jae-Hwan; Jung, Bong-Kwang

    2014-01-01

    Mucosal immune responses against Pygidiopsis summa (Trematoda: Heterophyidae) infection were studied in ICR mice. Experimental groups consisted of group 1 (uninfected controls), group 2 (infection with 200 metacercariae), and group 3 (immunosuppression with Depo-Medrol and infection with 200 metacercariae). Worms were recovered in the small intestine at days 1, 3, 5, and 7 post-infection (PI). Intestinal intraepithelial lymphocytes (IEL), mast cells, and goblet cells were counted in intestinal tissue sections stained with Giemsa, astra-blue, and periodic acid-Schiff, respectively. Mucosal IgA levels were measured by ELISA. Expulsion of P. summa from the mouse intestine began to occur from days 3-5 PI which sustained until day 7 PI. The worm expulsion was positively correlated with proliferation of IEL, mast cells, goblet cells, and increase of IgA, although in the case of mast cells significant increase was seen only at day 7 PI. Immunosuppression suppressed all these immune effectors and inhibited worm reduction in the intestine until day 7 PI. The results suggested that various immune effectors which include IEL, goblet cells, mast cells, and IgA play roles in regulating the intestinal mucosal immunity of ICR mice against P. summa infection. PMID:24623878

  15. Galectin-3: A Friend but Not a Foe during Trypanosoma cruzi Experimental Infection

    Directory of Open Access Journals (Sweden)

    Aline A. da Silva

    2017-11-01

    Full Text Available Trypanosoma cruzi interacts with host cells, including cardiomyocytes, and induces the production of cytokines, chemokines, metalloproteinases, and glycan-binding proteins. Among the glycan-binding proteins is Galectin-3 (Gal-3, which is upregulated after T. cruzi infection. Gal-3 is a member of the lectin family with affinity for β-galactose containing molecules; it can be found in both the nucleus and the cytoplasm and can be either membrane-associated or secreted. This lectin is involved in several immunoregulatory and parasite infection process. Here, we explored the consequences of Gal-3 deficiency during acute and chronic T. cruzi experimental infection. Our results demonstrated that lack of Gal-3 enhanced in vitro replication of intracellular parasites, increased in vivo systemic parasitaemia, and reduced leukocyte recruitment. Moreover, we observed decreased secretion of pro-inflammatory cytokines in spleen and heart of infected Gal-3 knockout mice. Lack of Gal-3 also led to elevated mast cell recruitment and fibrosis of heart tissue. In conclusion, galectin-3 expression plays a pivotal role in controlling T. cruzi infection, preventing heart damage and fibrosis.

  16. Cardiac plexus of dogs experimentally infected with Trypanosoma cruzi: inflammatory lesions and quantitative studies

    Directory of Open Access Journals (Sweden)

    Marcelo V. Caliari

    1995-03-01

    Full Text Available Qualitative and quantitative aspects of the superficial and profound cardiac plexus of dogs experimentally infected with Be-62 and Be-78 strains of Trypanosoma cruzi were studied. Animals were autopsied in the acute phase of infection. The inflammatory process, lesions and number of parasites were more intense and frequent in animals infected with the Be-78 strain than in those infected with Be-62. Despite this, no statistically significant differences could be found between the number of neuron bodies in the ganglia of infected and control dogs.Foi realizado estudo qualitativo e quantitativo dos plexos cardíacos superficiais e profundos em cães inoculados com o Trypanosoma cruzi das cepas Be-62 e Be-78 e sacrificados na fase aguda. O processo inflamatório, as lesões e o parasitismo dos plexos foram mais intensos e frequentes nos animais inoculados com a cepa Be-78 do que naqueles inoculados com a cepa Be- 62. Apesar deste fato, não foi verificada diferença estatisticamente significativa entre o número de corpos de neurônio por gânglio dos animais chagásicos e os controles.

  17. Testing sex ratio theory with the malaria parasite Plasmodium mexicanum in natural and experimental infections.

    Science.gov (United States)

    Neal, Allison T; Schall, Jos J

    2014-04-01

    The malaria parasite (Plasmodium) life history accords well with the assumptions of local mate competition (LMC) of sex ratio theory. Within a single meal of the blood-feeding vector, sexually dimorphic gametocyte cells produce gametes (females produce one, males several) that mate and undergo sexual recombination. The theory posits several factors drive the Plasmodium sex ratio: male fecundity (gametes/male gametocyte), number and relative abundance of parasite clones, and gametocyte density. We measured these traits for the lizard malaria parasite, Plasmodium mexicanum, with a large sample of natural infections and infections from experiments that manipulated clonal diversity. Sex ratio in single-clone infections was slightly female-biased, but matched predictions of theory for this low-fecundity species. Sex ratio was less female-biased in clonally diverse infections as predicted by LMC for the experimental, but not natural infections. Gametocyte density was not positively related to sex ratio. These results are explained by the P. mexicanum life history of naturally low clonal diversity and high gametocyte production. This is the first study of a natural malaria system that examines all traits relevant to LMC in individual vertebrate hosts and suggests a striking example of sex ratio theory having significance for human public health. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  18. Virus-specific cytotoxic T cells in chronic active Epstein-Barr virus infection.

    Science.gov (United States)

    Shibayama, Haruna; Imadome, Ken-Ichi; Onozawa, Erika; Tsuzura, Akiho; Miura, Osamu; Koyama, Takatoshi; Arai, Ayako

    2017-01-01

    Chronic active Epstein-Barr virus infection (CAEBV) is a disease characterized by clonally proliferating and activated EBV-infected T or NK cells accompanied by chronic inflammation and T- or NK-cell neoplasms. However, the mechanism for developing CAEBV has not been clarified to date. Because the decreased number or inactivation of EBV-specific cytotoxic T lymphocytes (CTLs) resulted in the development of EBV-positive B-cell neoplasms, we investigated the number of CTLs in CAEBV patients using the tetrameric complexes of HLA-restricted EBV-specific peptides. Among the seven patients examined, EBV-specific CTLs were detected in the peripheral blood mononuclear cells (PBMCs) of four cases but were not detected in three cases. The ratio of EBV-specific CTLs in PBMCs tended to be higher in the patients with active disease than in those with inactive disease. In two patients in whom EBV-specific CTLs had not been detected, CTLs appeared after the eradication of EBV-infected T cells by allogeneic bone marrow transplantation. These results suggested that the failure of CTLs had a role in developing CAEBV, although the induction number and function of EBV-specific CTLs might vary in each patient.

  19. Linear Multiepitope (Glyco)peptides for Type-Specific Serology of Herpes Simplex Virus (HSV) Infections.

    Science.gov (United States)

    Risinger, Christian; Sørensen, Kasper K; Jensen, Knud J; Olofsson, Sigvard; Bergström, Tomas; Blixt, Ola

    2017-05-12

    Detection of type-specific antibodies is an important and essential part of accurate diagnosis, even in silent carriers of herpes simplex virus (HSV)-1 (oral) and HSV-2 (genital) infections. Serologic assays that identify HSV-1 and HSV-2 type-specific antibodies have been commercially available for more than a decade but often face problems related to cross-reactivity and similar issues. Attempts to identify type-specific peptide epitopes for use in serology for both HSV-1 and HSV-2 have been limited. We recently demonstrated epitope mapping of envelope glycoprotein G2 and identified a type-specific glycopeptide epitope that broadly recognized HSV-2 infected individuals. In the present work we have performed a comprehensive glycopeptide synthesis and microarray epitope mapping of 14 envelope proteins from HSV-1 and HSV-2, namely, gB, gC, gD, gE, gG, gH, and gI, using sera from HSV-1- and HSV-2-infected individuals and control sera. Several unique type-specific peptide epitopes with high sensitivity were identified and synthesized as one large linear multiepitope sequence using microwave-assisted solid-phase (glyco)peptide synthesis. Microarray validation with clinically defined HSV and Varicella Zoster (VZV) sera confirmed excellent cumulative specificities and sensitivities.

  20. Clinico-pathological studies in cattle experimentally infected with Taenia saginata eggs : research communication

    Directory of Open Access Journals (Sweden)

    A. Oryan

    1998-07-01

    Full Text Available Calves 1-2 months old were experimentally infected with eggs of Taenia saginata and clinical and haematological deviations, development and distribution of cysticerci and pathological changes were recorded. The calves infected with 5 000, 10 000 or 50 000 eggs showed an increase in pulse and respiratory rates. The animals that received 50 000 eggs had significantly increased pulse (p<0.05 and respiratory rates (p<0.005. The symptoms were more severe in young, 30-day-old calves infected with 50 000 eggs. Haemoglobin concentration, haematocrit values and red blood cell count decreased, but white blood cell count increased slightly. Lymphocytes and eosinophils also increased up to 88%and 14% (p<0.05, respectively. Most of the cysticerci were not fully formed 1 month post-infection, but at 2 months the cysts were fully mature and at 4 months, some cysts had degenerated. There was no uniformpattern of distribution of cysticerci in the body of infected calves, but the most commonly affected sites were masseter and heart muscles, followed by diaphragm, tongue and other skeletal muscles. The maximum concentration of 8-14 cysticerci per 10 g of tissue was recorded in masseter muscles and heart. The affected parts revealed tissue reactions that included pressure atrophy, necrosis and fibrosis. Microscopically, the lesions comprised infiltration with lymphocytes, plasma cells, eosinophils and macrophages, fibrosis, necrosis and calcification. The tissue reaction was severe in calves infected with 50 000 eggs. The severity of clinical signs, haematological and pathological changes depended mostly on the age of the animals and dose of infection.

  1. Experimental Infection of Rabbits with Rabbit and Genotypes 1 and 4 Hepatitis E Viruses

    Science.gov (United States)

    Ma, Hongxia; Zheng, Lin; Liu, Yunbo; Zhao, Chenyan; Harrison, Tim J.; Ma, Yuyuan; Sun, Shuhua; Zhang, Jingang; Wang, Youchun

    2010-01-01

    Background A recent study provided evidence that farmed rabbits in China harbor a novel hepatitis E virus (HEV) genotype. Although the rabbit HEV isolate had 77–79% nucleotide identity to the mammalian HEV genotypes 1 to 4, their genomic organization is very similar. Since rabbits are used widely experimentally, including as models of infection, we investigated whether they constitute an appropriate animal model for human HEV infection. Methods Forty-two SPF rabbits were divided randomly into eleven groups and inoculated with six different isolates of rabbit HEV, two different doses of a second-passage rabbit HEV, and with genotype 1 and 4 HEV. Sera and feces were collected weekly after inoculation. HEV antigen, RNA, antibody and alanine aminotransferase in sera and HEV RNA in feces were detected. The liver samples were collected during necropsy subject to histopathological examination. Findings Rabbits inoculated with rabbit HEV became infected with HEV, with viremia, fecal virus shedding and high serum levels of viral antigens, and developed hepatitis, with elevation of the liver enzyme, ALT. The severity of disease corresponded to the infectious dose (genome equivalents), with the most severe hepatic disease caused by strain GDC54-18. However, only two of nine rabbits infected with HEV genotype 4, and none infected with genotype 1, developed hepatitis although six of nine rabbits inoculated with the genotype 1 HEV and in all rabbits inoculated with the genotype 4 HEV seroconverted to be positive for anti-HEV IgG antibody by 14 weeks post-inoculation. Conclusions These data indicate that rabbits are an appropriate model for rabbit HEV infection but are not likely to be useful for the study of human HEV. The rabbit HEV infection of rabbits may provide an appropriate parallel animal model to study HEV pathogenesis. PMID:20161794

  2. Experimental infection of rabbits with rabbit and genotypes 1 and 4 hepatitis E viruses.

    Science.gov (United States)

    Ma, Hongxia; Zheng, Lin; Liu, Yunbo; Zhao, Chenyan; Harrison, Tim J; Ma, Yuyuan; Sun, Shuhua; Zhang, Jingang; Wang, Youchun

    2010-02-11

    A recent study provided evidence that farmed rabbits in China harbor a novel hepatitis E virus (HEV) genotype. Although the rabbit HEV isolate had 77-79% nucleotide identity to the mammalian HEV genotypes 1 to 4, their genomic organization is very similar. Since rabbits are used widely experimentally, including as models of infection, we investigated whether they constitute an appropriate animal model for human HEV infection. Forty-two SPF rabbits were divided randomly into eleven groups and inoculated with six different isolates of rabbit HEV, two different doses of a second-passage rabbit HEV, and with genotype 1 and 4 HEV. Sera and feces were collected weekly after inoculation. HEV antigen, RNA, antibody and alanine aminotransferase in sera and HEV RNA in feces were detected. The liver samples were collected during necropsy subject to histopathological examination. Rabbits inoculated with rabbit HEV became infected with HEV, with viremia, fecal virus shedding and high serum levels of viral antigens, and developed hepatitis, with elevation of the liver enzyme, ALT. The severity of disease corresponded to the infectious dose (genome equivalents), with the most severe hepatic disease caused by strain GDC54-18. However, only two of nine rabbits infected with HEV genotype 4, and none infected with genotype 1, developed hepatitis although six of nine rabbits inoculated with the genotype 1 HEV and in all rabbits inoculated with the genotype 4 HEV seroconverted to be positive for anti-HEV IgG antibody by 14 weeks post-inoculation. These data indicate that rabbits are an appropriate model for rabbit HEV infection but are not likely to be useful for the study of human HEV. The rabbit HEV infection of rabbits may provide an appropriate parallel animal model to study HEV pathogenesis.

  3. Experimental infection of rabbits with rabbit and genotypes 1 and 4 hepatitis E viruses.

    Directory of Open Access Journals (Sweden)

    Hongxia Ma

    Full Text Available BACKGROUND: A recent study provided evidence that farmed rabbits in China harbor a novel hepatitis E virus (HEV genotype. Although the rabbit HEV isolate had 77-79% nucleotide identity to the mammalian HEV genotypes 1 to 4, their genomic organization is very similar. Since rabbits are used widely experimentally, including as models of infection, we investigated whether they constitute an appropriate animal model for human HEV infection. METHODS: Forty-two SPF rabbits were divided randomly into eleven groups and inoculated with six different isolates of rabbit HEV, two different doses of a second-passage rabbit HEV, and with genotype 1 and 4 HEV. Sera and feces were collected weekly after inoculation. HEV antigen, RNA, antibody and alanine aminotransferase in sera and HEV RNA in feces were detected. The liver samples were collected during necropsy subject to histopathological examination. FINDINGS: Rabbits inoculated with rabbit HEV became infected with HEV, with viremia, fecal virus shedding and high serum levels of viral antigens, and developed hepatitis, with elevation of the liver enzyme, ALT. The severity of disease corresponded to the infectious dose (genome equivalents, with the most severe hepatic disease caused by strain GDC54-18. However, only two of nine rabbits infected with HEV genotype 4, and none infected with genotype 1, developed hepatitis although six of nine rabbits inoculated with the genotype 1 HEV and in all rabbits inoculated with the genotype 4 HEV seroconverted to be positive for anti-HEV IgG antibody by 14 weeks post-inoculation. CONCLUSIONS: These data indicate that rabbits are an appropriate model for rabbit HEV infection but are not likely to be useful for the study of human HEV. The rabbit HEV infection of rabbits may provide an appropriate parallel animal model to study HEV pathogenesis.

  4. Acute phase response elicited by experimental bovine diarrhea virus (BVDV) infection is associated with decreased vitamin D and E status of vitamin-replete preruminant calves.

    Science.gov (United States)

    Nonnecke, B J; McGill, J L; Ridpath, J F; Sacco, R E; Lippolis, J D; Reinhardt, T A

    2014-09-01

    Studies in young animals have shown an association between vitamin deficiencies and increased risk of infectious disease; however, there is a paucity of information regarding the effect of acute infection on the vitamin status of the vitamin-replete neonate. To characterize the effects of acute infection on vitamin D and E status of the neonate, 6 vitamin-replete preruminant Holstein bull calves were experimentally infected with bovine viral diarrhea virus (BVDV; strain BVDV2-1373). Six mock-inoculated calves served as controls. Sustained pyrexia, leukopenia, and asynchronous increases in serum haptoglobin and serum amyloid A characterized the response of calves to infection with BVDV. Infection was also associated with increased serum IFN-γ, IL-2, and IL-6 concentrations. During the last 8 d of the 14-d postinoculation period, serum 25-hydroxyvitamin D and α-tocopherol concentrations in infected calves decreased by 51 and 82%, respectively. The observed inverse association between vitamin D and E status and serum amyloid A in infected calves suggests that the infection-induced acute phase response contributed to the reduced vitamin status of these animals. Additional studies are necessary to determine if the negative effect of infection on status are unique to this specific infection model or is representative of preruminant calf's response to acute infection. Studies are also needed to characterize mechanisms underlying infection-related changes in vitamin D and E status and to determine whether additional vitamin D or E supplementation during an acute infection diminishes disease severity and duration in the young animal. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  5. Different infective forms trigger distinct immune response in experimental Chagas disease.

    Directory of Open Access Journals (Sweden)

    Paula Melo de Abreu Vieira

    Full Text Available Although metacyclic and blood trypomastigotes are completely functional in relation to parasite-host interaction and/or target cell invasion, they differ in the molecules present on the surface. Thus, aspects related to the variability that the forms of T. cruzi interacts with host cells may lead to fundamental implications on the immune response against this parasite and, consequently, the clinical evolution of Chagas disease. We have shown that BT infected mice presented higher levels of parasitemia during all the acute phase of infection. Moreover, the infection with either MT or BT forms resulted in increased levels of total leukocytes, monocytes and lymphocytes, specifically later for MT and earlier for BT. The infection with BT forms presented earlier production of proinflammatory cytokine TNF-α and later of IFN-γ by both T cells subpopulations. This event was accompanied by an early cardiac inflammation with an exacerbation of this process at the end of the acute phase. On the other hand, infection with MT forms result in an early production of IFN-γ, with subsequent control in the production of this cytokine by IL-10, which provided to these animals an immunomodulatory profile in the end of the acute phase. These results are in agreement with what was found for cardiac inflammation where animals infected with MT forms showed intense cardiac inflammation later at infection, with a decrease in the same at the end of this phase. In summary, our findings emphasize the importance of taking into account the inoculums source of T. cruzi, since vectorial or transfusional routes of T. cruzi infection may trigger distinct parasite-host interactions during the acute phase that may influence relevant biological aspects of chronic Chagas disease.

  6. Different Infective Forms Trigger Distinct Immune Response in Experimental Chagas Disease

    Science.gov (United States)

    Vieira, Paula Melo de Abreu; Francisco, Amanda Fortes; Machado, Evandro Marques de Meneses; Nogueira, Nívia Carolina; Fonseca, Kátia da Silva; Reis, Alexandre Barbosa; Teixeira-Carvalho, Andrea; Martins-Filho, Olindo Assis; Tafuri, Washington Luiz; Carneiro, Cláudia Martins

    2012-01-01

    Although metacyclic and blood trypomastigotes are completely functional in relation to parasite-host interaction and/or target cell invasion, they differ in the molecules present on the surface. Thus, aspects related to the variability that the forms of T. cruzi interacts with host cells may lead to fundamental implications on the immune response against this parasite and, consequently, the clinical evolution of Chagas disease. We have shown that BT infected mice presented higher levels of parasitemia during all the acute phase of infection. Moreover, the infection with either MT or BT forms resulted in increased levels of total leukocytes, monocytes and lymphocytes, specifically later for MT and earlier for BT. The infection with BT forms presented earlier production of proinflammatory cytokine TNF-α and later of IFN-γ by both T cells subpopulations. This event was accompanied by an early cardiac inflammation with an exacerbation of this process at the end of the acute phase. On the other hand, infection with MT forms result in an early production of IFN-γ, with subsequent control in the production of this cytokine by IL-10, which provided to these animals an immunomodulatory profile in the end of the acute phase. These results are in agreement with what was found for cardiac inflammation where animals infected with MT forms showed intense cardiac inflammation later at infection, with a decrease in the same at the end of this phase. In summary, our findings emphasize the importance of taking into account the inoculums source of T. cruzi, since vectorial or transfusional routes of T. cruzi infection may trigger distinct parasite-host interactions during the acute phase that may influence relevant biological aspects of chronic Chagas disease. PMID:22412949

  7. Antibiotic embedded absorbable prosthesis for prevention of surgical mesh infection: experimental study in rats.

    Science.gov (United States)

    Suárez-Grau, J M; Morales-Conde, S; González Galán, V; Martín Cartes, J A; Docobo Durantez, F; Padillo Ruiz, F J

    2015-04-01

    Ventral hernias are a common problem in a general surgery and hernioplasty is an integral part of a general surgeon's practice. The use of prosthetic material has drastically reduced the risk of recurrence, but has introduced additional potential complications such as surgical wound infections, adhesion formation, graft rejection, etc. The development of a wound infection in a hernia that is repaired with a prosthetic material is a grave complication, often requiring removal of the prosthesis. This experimental study examined efficacy of completely absorbable, hydrophilic, PGA-TMC (polyglycolic acid-trimethylene carbonate) prosthesis impregnated with antibiotic for reduction of infectious complications. Antibiotic-impregnated PGA-TMC prostheses were placed intraperitoneally in 90 Wistar white rats that were randomized and distributed into four groups. Group 0 (23 rats): there were placed PGA-TMC prosthesis without antibiotic impregnation (control group). Group 1 (25 rats): meshes were placed and infected later with 1 × 10(8) UFC of S. aureus/1 ml/2 cm(2) (Staphylococcus aureus ATCC 6538 American Type Culture Collection, Rockville, MD). Group 2 (21 rats): cefazolin-impregnated prostheses were placed (1 g × 100 ml, at the rate of 1 ml/cm(2) of prosthesis) and were subsequently infected with the same bacterial inoculate. Group 3 (21 rats): cefazolin-impregnated prostheses with double quantity of cefazolin and infected. A week later these animals were killed and specimens were extracted for bacterial quantification and histological studies. Evident decrease of bacterial colonization was observed in series 2 and 3 [the ones impregnated with cefazolin, in comparison with the group 1 (infected without previous antibiotic impregnation)] with statistically significant results (p prosthesis when placing it in contact with intraabdominal viscera. However, cefazolin impregnation of the mesh has reduced an adhesion formation, mostly when the infection reached a

  8. Chicken line-dependent mortality after experimental infection with three type IIxIII recombinant Toxoplasma gondii clones.

    Science.gov (United States)

    Schares, G; Herrmann, D C; Maksimov, P; Matzkeit, B; Conraths, F J; Moré, G; Preisinger, R; Weigend, S

    2017-09-01

    Three genetically different clones of Toxoplasma gondii, also different in mouse virulence, were studied by experimental infection in chickens. For the experiments, four chicken lines were used, which differed in phylogenetic origin and performance level: two white egg layer lines, one with high laying performance (WLA), one with low (R11) and two brown layer lines, also displaying high (BLA) and low (L68) egg number. Chickens were intraperitoneally infected with three different T. gondii isolates representing type IIxIII recombinant clones, i.e. showing both, type II- and type III-specific alleles. These clones (K119/2 2C10, B136/1 B6H6, K119/2 A7) had exhibited virulence differences in a mouse model. In chickens, a significantly higher mortality was observed in white layer lines, but not in brown layer lines, suggesting that differences in the phylogenetic background may influence the susceptibility of chickens for toxoplasmosis. In addition, antibody (IgY) levels varied in surviving chickens at 31 days post infection. While low to intermediate antibody levels were observed in white layers, intermediate to high levels were measured in brown layers. Infection with a T. gondii clone showing low chicken virulence resulted in higher antibody levels in all chicken lines compared to infection with T. gondii clones of intermediate or high chicken virulence. This was in agreement with the parasite load as determined by real-time PCR. Overall, results show that progeny resulting from natural sexual recombination of T. gondii clonal lineages, may differ in their virulence for mice and chickens. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Specific-pathogen-free pigs as an animal model for studying Chlamydia trachomatis genital infection.

    Science.gov (United States)

    Vanrompay, Daisy; Hoang, Thi Q T; De Vos, Liselotte; Verminnen, Kristel; Harkinezhad, Taher; Chiers, Koen; Morré, Servaas A; Cox, Eric

    2005-12-01

    The purpose of the present study was to evaluate pigs as a large-animal model for female genital infection with two Chlamydia trachomatis human serovar E strains. Sixteen-week-old specific-pathogen-free female pigs (gilts) were intravaginally infected with the trachoma type E reference strain Bour or the urogenital serovar E strain 468. Several conclusions can be drawn from our findings on the pathogenicity of a primary C. trachomatis genital infection in gilts. First of all, we demonstrated that the serovar E strains Bour and 468 could ascend in the genital tract of gilts. The serovar E strains could replicate in the superficial columnar cervical epithelium and in the superficial epithelial layer of the uterus, which are known to be the specific target sites for a C. trachomatis genital infection in women. Second, inflammation and pathology occurred at the replication sites. Third, the organisms could trigger a humoral immune response, as demonstrated by the presence of immunoglobulin M (IgM), IgG, and IgA in both serum and genital secretion samples. Our findings imply that the pig model might be useful for studying the pathology, pathogenesis, and immune response to a C. trachomatis infection of the genital system.

  10. Histological assessment of granulomas in natural and experimental Schistosoma mansoni infections using whole slide imaging.

    Directory of Open Access Journals (Sweden)

    Kátia B Amaral

    Full Text Available The pathology of schistosomiasis mansoni, a neglected tropical disease of great clinical and socioeconomic importance, results from the parasite eggs that become trapped in host tissues, particularly in the liver and intestines. Continuous antigenic stimulation from these eggs leads to recruitment of inflammatory cells to the sites of infection with formation of periovular granulomas. These complex structures have variable size and composition and are the most striking histopathological feature of schistosomiasis mansoni. However, evaluation of granulomas by conventional microscopy methods is time-consuming and limited, especially in large-scale studies. Here, we used high resolution Whole Slide Imaging (WSI, which allows fast scanning of entire histological slides, and multiple morphometric evaluations, to assess the granulomatous response elicited in target organs (liver, small and large intestines of two models of schistosomiasis mansoni. One of the advantages of WSI, also termed virtual microscopy, is that it generates images that simultaneously offer high resolution and a wide field of observation. By using a model of natural (Nectomys squamipes, a wild reservoir captured from endemic areas in Brazil and experimental (Swiss mouse infection with Schistosoma mansoni, we provided the first detailed WSI characterization of granulomas and other pathological aspects. WSI and quantitative analyses enabled a fast and reliable assessment of the number, evolutional types, frequency and areas of granulomas and inflammatory infiltrates and revealed that target organs are differentially impacted by inflammatory responses in the natural and experimental infections. Remarkably, high-resolution analysis of individual eosinophils, key cells elicited by this helminthic infection, showed a great difference in eosinophil numbers between the two infections. Moreover, features such as the intestinal egg path and confluent granulomas were uncovered. Thus, WSI may

  11. Efficiency of the oral, intramuscular and subcutaneous routes for the experimental infection of hamster and sheep with Schistosoma bovis.

    Science.gov (United States)

    Oleaga, Ana; Ramajo, Vicente

    2004-09-20

    The percutaneous administration of cercariae is the usual method for experimental infections with Schistosoma bovis. These procedures are laborious and have important inconveniences when working with a large number of animals, especially if they are ruminants. In the present study, the efficiency of the oral, intramuscular and subcutaneous routes are evaluated by comparison with the percutaneous route in experimental infections with S. bovis. The infections developed in hamsters and sheep were evaluated taking as a basis the parasite burden, the concentrations of eggs in tissues and the levels of anti-Schistosoma antibodies. The oral infection failed in both hamsters and sheep. The administration of the cercariae by the intramuscular route was effective in sheep, developing infections of intensity similar to that of the infections acquired percutaneously. In hamsters, on the contrary, although all the animals developed the infection, they were very little intense. The injection of the cercariae by the subcutaneous route induces acceptable infections in hamsters and can also be an alternative route to percutaneous exposure. The levels of the anti-Schistosoma bovis antibodies detected in hamster and sheep were proportional to the number of worms present, which shows that the humoral response is a good indicator of the intensity of the infections. It can be concluded that the intramuscular route is a good alternative to the percutaneous route for experimental infections of sheep with S. bovis. Likewise, the subcutaneous route can also substitute, with some advantages, the percutaneous infections in hamsters.

  12. Optimised chronic infection models demonstrate that siderophore 'cheating' in Pseudomonas aeruginosa is context specific.

    Science.gov (United States)

    Harrison, Freya; McNally, Alan; da Silva, Ana C; Heeb, Stephan; Diggle, Stephen P

    2017-11-01

    The potential for siderophore mutants of Pseudomonas aeruginosa to attenuate virulence during infection, and the possibility of exploiting this for clinical ends, have attracted much discussion. This has largely been based on the results of in vitro experiments conducted in iron-limited growth medium, in which siderophore mutants act as social 'cheats:' increasing in frequency at the expense of the wild type to result in low-productivity, low-virulence populations dominated by mutants. We show that insights from in vitro experiments cannot necessarily be transferred to infection contexts. First, most published experiments use an undefined siderophore mutant. Whole-genome sequencing of this strain revealed a range of mutations affecting phenotypes other than siderophore production. Second, iron-limited medium provides a very different environment from that encountered in chronic infections. We conducted cheating assays using defined siderophore deletion mutants, in conditions designed to model infected fluids and tissue in cystic fibrosis lung infection and non-healing wounds. Depending on the environment, siderophore loss led to cheating, simple fitness defects, or no fitness effect at all. Our results show that it is crucial to develop defined in vitro models in order to predict whether siderophores are social, cheatable and suitable for clinical exploitation in specific infection contexts.

  13. Optimised chronic infection models demonstrate that siderophore ‘cheating’ in Pseudomonas aeruginosa is context specific

    Science.gov (United States)

    Harrison, Freya; McNally, Alan; da Silva, Ana C; Heeb, Stephan; Diggle, Stephen P

    2017-01-01

    The potential for siderophore mutants of Pseudomonas aeruginosa to attenuate virulence during infection, and the possibility of exploiting this for clinical ends, have attracted much discussion. This has largely been based on the results of in vitro experiments conducted in iron-limited growth medium, in which siderophore mutants act as social ‘cheats:’ increasing in frequency at the expense of the wild type to result in low-productivity, low-virulence populations dominated by mutants. We show that insights from in vitro experiments cannot necessarily be transferred to infection contexts. First, most published experiments use an undefined siderophore mutant. Whole-genome sequencing of this strain revealed a range of mutations affecting phenotypes other than siderophore production. Second, iron-limited medium provides a very different environment from that encountered in chronic infections. We conducted cheating assays using defined siderophore deletion mutants, in conditions designed to model infected fluids and tissue in cystic fibrosis lung infection and non-healing wounds. Depending on the environment, siderophore loss led to cheating, simple fitness defects, or no fitness effect at all. Our results show that it is crucial to develop defined in vitro models in order to predict whether siderophores are social, cheatable and suitable for clinical exploitation in specific infection contexts. PMID:28696423

  14. Potential evidence for biotype-specific chemokine profile following BVDV infection of bovine macrophages.

    Science.gov (United States)

    Burr, Stephen; Thomas, Carole; Brownlie, Joe; Offord, Victoria; Coffey, Tracey J; Werling, Dirk

    2012-11-15

    Chemokines play a key role in initiating the innate and subsequently adaptive immune response by recruiting immune cells to the site of an infection. Monocytes/macrophages (MØ) are part of the first line of defence against invading pathogens, and have been shown to release a variety of chemokines in response to infection. Here, we reveal the early transcriptional response of MØ to infection with cytopathogenic (cp) and non-cytopathogenic (ncp) bovine viral diarrhoea strains (BVDV). We demonstrate up-regulation of several key chemokines of the CCL and CXCL families in MØ exposed to cpBVDV, but not ncpBVDV. In contrast, infection of MØ with ncpBVDV led to down-regulation of chemokine mRNA expression compared to uninfected cells. Data suggest that ncpBVDV can shut down production of several key chemokines that play crucial roles in the immune response to infection. This study helps to further our understanding of the pathogenesis of BVDV infection, highlighting biotype-specific cellular responses. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Leptospira interrogans stably infects zebrafish embryos, altering phagocyte behavior and homing to specific tissues.

    Directory of Open Access Journals (Sweden)

    J Muse Davis

    2009-06-01

    Full Text Available Leptospirosis is an extremely widespread zoonotic infection with outcomes ranging from subclinical infection to fatal Weil's syndrome. Despite the global impact of the disease, key aspects of its pathogenesis remain unclear. To examine in detail the earliest steps in the host response to leptospires, we used fluorescently labelled Leptospira interrogans serovar Copenhageni to infect 30 hour post fertilization zebrafish embryos by either the caudal vein or hindbrain ventricle. These embryos have functional innate immunity but have not yet developed an adaptive immune system. Furthermore, they are optically transparent, allowing direct visualization of host-pathogen interactions from the moment of infection. We observed rapid uptake of leptospires by phagocytes, followed by persistent, intracellular infection over the first 48 hours. Phagocytosis of leptospires occasionally resulted in formation of large cellular vesicles consistent with apoptotic bodies. By 24 hours, clusters of infected phagocytes were accumulating lateral to the dorsal artery, presumably in early hematopoietic tissue. Our observations suggest that phagocytosis may be a key defense mechanism in the early stages of leptospirosis, and that phagocytic cells play roles in immunopathogenesis and likely in the dissemination of leptospires to specific target tissues.

  16. Correlation of serotype-specific dengue virus infection with clinical manifestations.

    Directory of Open Access Journals (Sweden)

    Eric S Halsey

    Full Text Available Disease caused by the dengue virus (DENV is a significant cause of morbidity throughout the world. Although prior research has focused on the association of specific DENV serotypes (DENV-1, DENV-2, DENV-3, and DENV-4 with the development of severe outcomes such as dengue hemorrhagic fever and dengue shock syndrome, relatively little work has correlated other clinical manifestations with a particular DENV serotype. The goal of this study was to estimate and compare the prevalence of non-hemorrhagic clinical manifestations of DENV infection by serotype.Between the years 2005-2010, individuals with febrile disease from Peru, Bolivia, Ecuador, and Paraguay were enrolled in an outpatient passive surveillance study. Detailed information regarding clinical signs and symptoms, as well as demographic information, was collected. DENV infection was confirmed in patient sera with polyclonal antibodies in a culture-based immunofluorescence assay, and the infecting serotype was determined by serotype-specific monoclonal antibodies. Differences in the prevalence of individual and organ-system manifestations were compared across DENV serotypes. One thousand seven hundred and sixteen individuals were identified as being infected with DENV-1 (39.8%, DENV-2 (4.3%, DENV-3 (41.5%, or DENV-4 (14.4%. When all four DENV serotypes were compared with each other, individuals infected with DENV-3 had a higher prevalence of musculoskeletal and gastrointestinal manifestations, and individuals infected with DENV-4 had a higher prevalence of respiratory and cutaneous manifestations.Specific clinical manifestations, as well as groups of clinical manifestations, are often overrepresented by an individual DENV serotype.

  17. Correlation of serotype-specific dengue virus infection with clinical manifestations.

    Science.gov (United States)

    Halsey, Eric S; Marks, Morgan A; Gotuzzo, Eduardo; Fiestas, Victor; Suarez, Luis; Vargas, Jorge; Aguayo, Nicolas; Madrid, Cesar; Vimos, Carlos; Kochel, Tadeusz J; Laguna-Torres, V Alberto

    2012-01-01

    Disease caused by the dengue virus (DENV) is a significant cause of morbidity throughout the world. Although prior research has focused on the association of specific DENV serotypes (DENV-1, DENV-2, DENV-3, and DENV-4) with the development of severe outcomes such as dengue hemorrhagic fever and dengue shock syndrome, relatively little work has correlated other clinical manifestations with a particular DENV serotype. The goal of this study was to estimate and compare the prevalence of non-hemorrhagic clinical manifestations of DENV infection by serotype. Between the years 2005-2010, individuals with febrile disease from Peru, Bolivia, Ecuador, and Paraguay were enrolled in an outpatient passive surveillance study. Detailed information regarding clinical signs and symptoms, as well as demographic information, was collected. DENV infection was confirmed in patient sera with polyclonal antibodies in a culture-based immunofluorescence assay, and the infecting serotype was determined by serotype-specific monoclonal antibodies. Differences in the prevalence of individual and organ-system manifestations were compared across DENV serotypes. One thousand seven hundred and sixteen individuals were identified as being infected with DENV-1 (39.8%), DENV-2 (4.3%), DENV-3 (41.5%), or DENV-4 (14.4%). When all four DENV serotypes were compared with each other, individuals infected with DENV-3 had a higher prevalence of musculoskeletal and gastrointestinal manifestations, and individuals infected with DENV-4 had a higher prevalence of respiratory and cutaneous manifestations. Specific clinical manifestations, as well as groups of clinical manifestations, are often overrepresented by an individual DENV serotype.

  18. Correlation of Serotype-Specific Dengue Virus Infection with Clinical Manifestations

    Science.gov (United States)

    Halsey, Eric S.; Marks, Morgan A.; Gotuzzo, Eduardo; Fiestas, Victor; Suarez, Luis; Vargas, Jorge; Aguayo, Nicolas; Madrid, Cesar; Vimos, Carlos; Kochel, Tadeusz J.; Laguna-Torres, V. Alberto

    2012-01-01

    Background Disease caused by the dengue virus (DENV) is a significant cause of morbidity throughout the world. Although prior research has focused on the association of specific DENV serotypes (DENV-1, DENV-2, DENV-3, and DENV-4) with the development of severe outcomes such as dengue hemorrhagic fever and dengue shock syndrome, relatively little work has correlated other clinical manifestations with a particular DENV serotype. The goal of this study was to estimate and compare the prevalence of non-hemorrhagic clinical manifestations of DENV infection by serotype. Methodology and Principal Findings Between the years 2005–2010, individuals with febrile disease from Peru, Bolivia, Ecuador, and Paraguay were enrolled in an outpatient passive surveillance study. Detailed information regarding clinical signs and symptoms, as well as demographic information, was collected. DENV infection was confirmed in patient sera with polyclonal antibodies in a culture-based immunofluorescence assay, and the infecting serotype was determined by serotype-specific monoclonal antibodies. Differences in the prevalence of individual and organ-system manifestations were compared across DENV serotypes. One thousand seven hundred and sixteen individuals were identified as being infected with DENV-1 (39.8%), DENV-2 (4.3%), DENV-3 (41.5%), or DENV-4 (14.4%). When all four DENV serotypes were compared with each other, individuals infected with DENV-3 had a higher prevalence of musculoskeletal and gastrointestinal manifestations, and individuals infected with DENV-4 had a higher prevalence of respiratory and cutaneous manifestations. Conclusions/Significance Specific clinical manifestations, as well as groups of clinical manifestations, are often overrepresented by an individual DENV serotype. PMID:22563516

  19. Molecular evolution of GB virus B hepatitis virus during acute resolving and persistent infections in experimentally infected tamarins

    DEFF Research Database (Denmark)

    Takikawa, Shingo; Engle, Ronald E; Faulk, Kristina N

    2010-01-01

    GB virus B (GBV-B) causes acute hepatitis in experimentally infected tamarins. We compared evolutionary features in acute resolving and persistent GBV-B infection. We detected no evidence of evolution in four animals with clearance during weeks 9-12, whereas three animals with clearance during......(-3) substitutions per site year(-1) during weeks 1-52 and 53-104, respectively. Thus, there was a significant decrease in evolution over time, as found for hepatitis C virus. The rate of non-synonymous substitution per non-synonymous site compared with that of synonymous substitution per synonymous site decreased...... weeks 13-26 had several substitutions in their polyprotein sequence. A single tamarin had long-term GBV-B viraemia; analysis of virus recovered at weeks 2, 5, 12, 20, 26, 52 and 104 demonstrated that mutations accumulated over time. Overall, the amino acid substitution rate was 3.5x10(-3) and 1.1x10...

  20. Experimental Ascaris suum infection in the pig: worm population kinetics following single inoculations with three doses of infective eggs.

    Science.gov (United States)

    Roepstorff, A; Eriksen, L; Slotved, H C; Nansen, P

    1997-10-01

    To study population kinetics during primary Ascaris suum infections, 3 groups of 52 pigs each were inoculated with 100, 1000, or 10,000 infective eggs. In all groups, the majority of larvae was found in the liver on day 3 post inoculation (p.i.) and in the lungs on day 7 p.i. Liver white spots, caused by migrating larvae, were most numerous at day 7 p.i., whereafter they gradually healed, and only low numbers of granulation-tissue type white spots and lymphonodular white spots persisted at days 21-56 p.i. Independent of dose level, 47-58% of the inoculated eggs were recovered as larvae in the small intestine on day 10 p.i., but most larvae were eliminated at days 17-21 p.i. This elimination started earlier and removed a higher percentage of the worms with increasing inoculation dose, resulting in small strongly aggregated worm populations by day 28 p.i. (k of the negative binomial distribution was low: 0.2-0.4) without significant differences between groups. Thus, overdispersion, which is a characteristic of both porcine and human ascarosis, is found here under experimental conditions where aggregation factors like host behaviour, transmission rate, host status etc have been partly or totally controlled.

  1. Calculator for the correction of the experimental specific migration for comparison with the legislative limit

    DEFF Research Database (Denmark)

    Petersen, Jens Højslev; Hoekstra, Eddo J.

    The EURL-NRL-FCM Taskforce on the Fourth Amendment of the Plastic Directive 2002/72/EC developed a calculator for the correction of the test results for comparison with the specific migration limit (SML). The calculator calculates the maximum acceptable specific migration under the given experime......The EURL-NRL-FCM Taskforce on the Fourth Amendment of the Plastic Directive 2002/72/EC developed a calculator for the correction of the test results for comparison with the specific migration limit (SML). The calculator calculates the maximum acceptable specific migration under the given...... experimental conditions in food or food stimulant and indicates whether the test result is in compliance with the legislation. This calculator includes the Fat Reduction Factor, the simulant D Reduction Factor and the factor of the difference in surface-to-volume ratio between test and real food contact....

  2. Distribution of sialic acid receptors and influenza A virus of avian and swine origin in experimentally infected pigs

    Directory of Open Access Journals (Sweden)

    Viuff Birgitte M

    2011-09-01

    Full Text Available Abstract Background Pigs are considered susceptible to influenza A virus infections from different host origins because earlier studies have shown that they have receptors for both avian (sialic acid-alpha-2,3-terminal saccharides (SA-alpha-2,3 and swine/human (SA-alpha-2,6 influenza viruses in the upper respiratory tract. Furthermore, experimental and natural infections in pigs have been reported with influenza A virus from avian and human sources. Methods This study investigated the receptor distribution in the entire respiratory tract of pigs using specific lectins Maackia Amurensis (MAA I, and II, and Sambucus Nigra (SNA. Furthermore, the predilection sites of swine influenza virus (SIV subtypes H1N1 and H1N2 as well as avian influenza virus (AIV subtype H4N6 were investigated in the respiratory tract of experimentally infected pigs using immunohistochemical methods. Results SIV antigen was widely distributed in bronchi, but was also present in epithelial cells of the nose, trachea, bronchioles, and alveolar type I and II epithelial cells in severely affected animals. AIV was found in the lower respiratory tract, especially in alveolar type II epithelial cells and occasionally in bronchiolar epithelial cells. SA-alpha-2,6 was the predominant receptor in all areas of the respiratory tract with an average of 80-100% lining at the epithelial cells. On the contrary, the SA-alpha-2,3 was not present (0% at epithelial cells of nose, trachea, and most bronchi, but was found in small amounts in bronchioles, and in alveoli reaching an average of 20-40% at the epithelial cells. Interestingly, the receptor expression of both SA-alpha-2,3 and 2,6 was markedly diminished in influenza infected areas compared to non-infected areas. Conclusions A difference in predilection sites between SIV and AIV virus was found, and this difference was in accordance with the distribution of the SA-alpha-2,6 and SA-alpha-2,3 receptor, respectively. The results indicated

  3. Fasciola hepatica: comparative metacercarial productions in experimentally-infected Galba truncatula and Pseudosuccinea columella

    Directory of Open Access Journals (Sweden)

    Vignoles Philippe

    2015-01-01

    Full Text Available As large numbers of metacercariae of Fasciola hepatica are necessary for research, experimental infections of Galba truncatula and Pseudosuccinea columella with this digenean were carried out to determine the better intermediate host for metacercarial production and, consequently, the most profitable snail for decreasing the cost price of these larvae. Pre-adult snails (4 mm in shell height originating from two populations per lymnaeid species were individually exposed to two or five miracidia, raised at 23 °C and followed for cercarial shedding up to their death. Compared to values noted in G. truncatula, the survival of P. columella on day 30 post-exposure was significantly greater, while the prevalence of F. hepatica infection was significantly lower. In the four P. columella groups, metacercarial production was significantly greater than that noted in the four groups of G. truncatula (347–453 per cercariae-shedding snail versus 163–275, respectively. Apart from one population of G. truncatula, the use of five miracidia per snail at exposure significantly increased the prevalence of F. hepatica in P. columella and the other population of G. truncatula, whereas it did not have any clear effect on the mean number of metacercariae. The use of P. columella for experimental infections with F. hepatica resulted in significantly higher metacercarial production than that noted with G. truncatula, in spite of a lower prevalence for the former lymnaeid. This finding allows for a significant decrease in the cost price of these larvae for commercial production.

  4. Buparvaquone is active against Neospora caninum in vitro and in experimentally infected mice

    Directory of Open Access Journals (Sweden)

    Joachim Müller

    2015-04-01

    Full Text Available The naphthoquinone buparvaquone is currently the only drug used against theileriosis. Here, the effects of buparvaquone were investigated in vitro and in an experimental mouse model for Neospora caninum infection. In 4-day proliferation assays, buparvaquone efficiently inhibited N. caninum tachyzoite replication (IC50 = 4.9 nM; IC100 = 100 nM. However, in the long term tachyzoites adapted and resumed proliferation in the presence of 100 nM buparvaquone after 20 days of cultivation. Parasiticidal activity was noted after 9 days of culture in 0.5 µM or 6 days in 1 µM buparvaquone. TEM of N. caninum infected fibroblasts treated with 1 µM buparvaquone showed that the drug acted rather slowly, and ultrastructural changes were evident only after 3–5 days of treatment, including severe alterations in the parasite cytoplasm, changes in the composition of the parasitophorous vacuole matrix and a diminished integrity of the vacuole membrane. Treatment of N. caninum infected mice with buparvaquone (100 mg/kg either by intraperitoneal injection or gavage prevented neosporosis symptoms in 4 out of 6 mice in the intraperitoneally treated group, and in 6 out of 7 mice in the group receiving oral treatment. In the corresponding controls, all 6 mice injected intraperitoneally with corn oil alone died of acute neosporosis, and 4 out of 6 mice died in the orally treated control group. Assessment of infection intensities in the treatment groups showed that, compared to the drug treated groups, the controls showed a significantly higher parasite load in the lungs while cerebral parasite load was higher in the buparvaquone-treated groups. Thus, although buparvaquone did not eliminate the parasites infecting the CNS, the drug represents an interesting lead with the potential to eliminate, or at least diminish, fetal infection during pregnancy.

  5. An experimental ovine Theileriosis: The effect of Theileria lestoquardi infection on cardiovascular system in sheep.

    Science.gov (United States)

    Yaghfoori, Saeed; Razmi, Gholam Reza; Mohri, Mehrdad; Razavizadeh, Ali Reza Taghavi; Movassaghi, Ahmad Reza

    2016-09-01

    The malignant ovine theileriosis is caused by Theileria lestoquardi, which is highly pathogenic in sheep. Theileriosis involves different organs in ruminants, but the effect of the disease on the cardiovascular system is unclear. To understand the pathogenesis of T. lestoquardi on the cardiovascular system, Baluchi breed sheep were infected with the mentioned parasite by releasing unfed adults of Hyalomma anatolicum anatolicum, which were infected with T. lestoquardi. The infected sheep were clinically examined on days 0, 2, 5, 7, 10, 12, 14, 17, and 21, and the blood samples were collected for biochemical parameters measurement. At termination of the experiment, the infected sheep were euthanized and pathological examinations of heart tissue were conducted. During experimental infection of sheep with T. lestoquardi, activities of cardiac troponin I (cTnI), lactate dehydrogenase, and aspartate aminotransferase, were significantly increased (P˂0.05), while a conspicuous decrease (P˂0.05) was observed in creatine phosphokinase activities. Alterations made in biochemical factors almost coincided with the presence of piroplasm in the blood and schizont in lymph nodes. Maximum and minimum of parasitemia in the sheep stood between 3.3% and 0.28%, respectively. In addition, electrocardiography revealed sinus tachycardia, sinus arrhythmia, sino-atrial block and ST-elevation, atrial premature beat, and alteration in QRS and in T waves' amplitude. Heart histopathological examination showed hyperemia, infiltration of mononuclear inflammatory cells into interstitial tissue, endocarditis, and focal necrosis of cardiac muscle cells. In addition, in one of the sheep, definite occurrence of infarction was observed. The results indicate that T. lestoquardi infection has devastating pathological impacts on the cardiovascular system of sheep. Furthermore, measurement of the cTnI amount is a useful biochemical factor for diagnosis and for better understanding of the severity and

  6. Buparvaquone is active against Neospora caninum in vitro and in experimentally infected mice

    Science.gov (United States)

    Müller, Joachim; Aguado-Martinez, Adriana; Manser, Vera; Balmer, Vreni; Winzer, Pablo; Ritler, Dominic; Hostettler, Isabel; Arranz-Solís, David; Ortega-Mora, Luis; Hemphill, Andrew

    2015-01-01

    The naphthoquinone buparvaquone is currently the only drug used against theileriosis. Here, the effects of buparvaquone were investigated in vitro and in an experimental mouse model for Neospora caninum infection. In 4-day proliferation assays, buparvaquone efficiently inhibited N. caninum tachyzoite replication (IC50 = 4.9 nM; IC100 = 100 nM). However, in the long term tachyzoites adapted and resumed proliferation in the presence of 100 nM buparvaquone after 20 days of cultivation. Parasiticidal activity was noted after 9 days of culture in 0.5 µM or 6 days in 1 µM buparvaquone. TEM of N. caninum infected fibroblasts treated with 1 µM buparvaquone showed that the drug acted rather slowly, and ultrastructural changes were evident only after 3–5 days of treatment, including severe alterations in the parasite cytoplasm, changes in the composition of the parasitophorous vacuole matrix and a diminished integrity of the vacuole membrane. Treatment of N. caninum infected mice with buparvaquone (100 mg/kg) either by intraperitoneal injection or gavage prevented neosporosis symptoms in 4 out of 6 mice in the intraperitoneally treated group, and in 6 out of 7 mice in the group receiving oral treatment. In the corresponding controls, all 6 mice injected intraperitoneally with corn oil alone died of acute neosporosis, and 4 out of 6 mice died in the orally treated control group. Assessment of infection intensities in the treatment groups showed that, compared to the drug treated groups, the controls showed a significantly higher parasite load in the lungs while cerebral parasite load was higher in the buparvaquone-treated groups. Thus, although buparvaquone did not eliminate the parasites infecting the CNS, the drug represents an interesting lead with the potential to eliminate, or at least diminish, fetal infection during pregnancy. PMID:25941626

  7. Experimental infection of rabbits with bovine viral diarrhoea virus by a natural route of exposure

    Science.gov (United States)

    2014-01-01

    Bovine viral diarrhoea virus (BVDV) is an important pathogen of cattle that can naturally infect a wide range of even-toed ungulates. Non-bovine hosts may represent reservoirs for the virus that have the potential to hamper BVDV eradication programs usually focused on cattle. Rabbits are very abundant in countries such as the United Kingdom or Australia and are often living on or near livestock pastures. Earlier reports indicated that rabbits can propagate BVDV upon intravenous exposure and that natural infection of rabbits with BVDV may occur but experimental proof of infection of rabbits by a natural route is lacking. Therefore, New Zealand White rabbits were exposed to a Scottish BVDV field strain intravenously, oro-nasally and by contaminating their hay with virus. None of the animals showed any clinical signs. However, the lymphoid organs from animals sacrificed at day five after exposure showed histological changes typical of transient infection with pestivirus. Most organ samples and some buffy coat samples were virus positive at day five but saliva samples remained negative. Development of antibodies was observed in all intravenously challenged animals, in all of the nebulised group and in four of six animals exposed to contaminated hay. To our knowledge this is the first report of BVDV propagation in a species other than ruminants or pigs after exposure to the virus by a natural route. However, to assess the role of rabbits as a potential reservoir for BVDV it remains to be determined whether persistent infection caused by intra-uterine infection is possible and whether BVDV is circulating in wild rabbit populations. PMID:24690167

  8. Pathophysiological variability of different genotypes of human Blastocystis hominis Egyptian isolates in experimentally infected rats.

    Science.gov (United States)

    Hussein, Eman M; Hussein, Abdalla M; Eida, Mohamed M; Atwa, Maha M

    2008-04-01

    The genotyping of Blastocystis hominis clinical isolates obtained from 28 gastrointestinal symptomatic patients and 16 asymptomatic individuals were identified by polymerase chain reaction using sequenced-tagged site (STS) primers. Then, pathophysiological variability between different B. hominis genotypes was evaluated in experimentally infected rats. Only four B. hominis subtypes (1, 2, 3, and 4) were detected (18.2%, 9.1%, 54.5%, and 18.2%, respectively) in human isolates. In symptomatic isolates, subtypes 1, 3, and 4 were detected in 8 (28.6%), 16 (57.1%), and 4 (14.3%) patients, respectively. In asymptomatic isolates, subtypes 2, 3, and 4 were identified in 4 (25%), 8 (50%), and 4 (25%), respectively. Subtype 3 was the commonest in humans. Different degrees of pathological changes were found among infected rats by symptomatic subtypes compared with asymptomatic subtypes. The moderate and severe degrees of pathological changes were found only in symptomatic subtypes infected rats while mild degree was found only in asymptomatic subtypes infected rats. Only subtype 1 induced mortality rate with 25% among infected rats. On evaluation of the intestinal cell permeability in the Ussing chamber, a prominent increase in short circuit current (DeltaIsc) was found in symptomatic subtype 1 compared to symptomatic subtypes 3 and 4 infected rats. Minimal effects were found in the asymptomatic and control groups. The results proved that subtype 1 was clinically and statistically highly relevant to the pathogenicity of B. hominis while subtype 2 was irrelevant. Also, the results suggest the presence of pathogenic and nonpathogenic strains among subtypes 3 and 4.

  9. Pathology, clinical signs, and tissue distribution of Toxoplasma gondii in experimentally infected reindeer (Rangifer tarandus

    Directory of Open Access Journals (Sweden)

    Émilie Bouchard

    2017-12-01

    Full Text Available Toxoplasma gondii is a zoonotic parasite found in vertebrates worldwide for which felids serve as definitive hosts. Despite low densities of felids in northern Canada, Inuit people in some regions show unexpectedly high levels of exposure, possibly through handling and consumption of Arctic wildlife. Free-ranging caribou (Rangifer tarandus are widely harvested for food across the Canadian North, show evidence of seroexposure to T. gondii, and are currently declining in numbers throughout the Arctic. We experimentally infected three captive reindeer (conspecific with caribou with 1000, 5000 or 10,000 oocysts of T. gondii via stomach intubation to assess clinical signs of infection, pathology, and tissue distribution. An unexposed reindeer served as a negative control. Signs of stress, aggression, and depression were noted for the first two weeks following infection. By 4 weeks post infection, all infected reindeer were positive on a modified agglutination test at the highest titer tested (1:200 for antibodies to T. gondii. At 20 weeks post infection, no gross abnormalities were observed on necropsy. Following histopathology and immunohistochemistry, tissue cysts were visualized in the reindeer given the highest and lowest dose of oocysts. Focal pleuritis and alveolitis were associated with respiratory problems in reindeer given the middle dose. DNA of T. gondii was detected following traditional DNA extraction and conventional PCR on 25 mg samples from 17/33 muscles and organs, and by magnetic capture DNA extraction from 100 g samples from all 26 tissues examined. This research demonstrated that reindeer/caribou can serve as intermediate hosts for T. gondii, and that the parasite may be associated with health effects in wildlife. The presence of T. gondii in all tissues tested, many of which are commonly consumed raw, smoked, or dried in northern communities, suggests that caribou may serve as a source of human exposure to T

  10. Infectious mononucleosis, other infections and prostate-specific antigen concentration as a marker of prostate involvement during infection.

    Science.gov (United States)

    Sutcliffe, Siobhan; Nevin, Remington L; Pakpahan, Ratna; Elliott, Debra J; Langston, Marvin E; De Marzo, Angelo M; Gaydos, Charlotte A; Isaacs, William B; Nelson, William G; Sokoll, Lori J; Walsh, Patrick C; Zenilman, Jonathan M; Cersovsky, Steven B; Platz, Elizabeth A

    2016-05-01

    Although Epstein-Barr virus has been detected in prostate tissue, no associations have been observed with prostate cancer in the few studies conducted to date. One possible reason for these null findings may be use of cumulative exposure measures that do not inform the timing of infection, i.e., childhood versus adolescence/early adulthood when infection is more likely to manifest as infectious mononucleosis (IM). We sought to determine the influence of young adult-onset IM on the prostate by measuring prostate-specific antigen (PSA) as a marker of prostate inflammation/damage among U.S. military members. We defined IM cases as men diagnosed with IM from 1998 to 2003 (n = 55) and controls as men without an IM diagnosis (n = 255). We selected two archived serum specimens for each participant, the first collected after diagnosis for cases and one randomly selected from 1998 to 2003 for controls (index), as well as the preceding specimen (preindex). PSA was measured in each specimen. To explore the specificity of our findings for prostate as opposed to systemic inflammation, we performed a post hoc comparison of other infectious disease cases without genitourinary involvement (n = 90) and controls (n = 220). We found that IM cases were more likely to have a large PSA rise than controls (≥ 20 ng/mL: 19.7% versus 8.8%, p = 0.027; ≥ 40% rise: 25.7% versus 9.4%, p = 0.0021), as were other infectious disease cases (25.7% versus 14.0%, p = 0.020; 27.7% versus 18.0%, p = 0.092). These findings suggest that, in addition to rising because of prostate infection, PSA may also rise because of systemic inflammation, which could have implications for PSA interpretation in older men. © 2015 UICC.

  11. Shared Immune and Repair Markers During Experimental Toxoplasma Chronic Brain Infection and Schizophrenia.

    Science.gov (United States)

    Tomasik, Jakub; Schultz, Tracey L; Kluge, Wolfgang; Yolken, Robert H; Bahn, Sabine; Carruthers, Vern B

    2016-03-01

    Chronic neurologic infection with Toxoplasma gondii is relatively common in humans and is one of the strongest known risk factors for schizophrenia. Nevertheless, the exact neuropathological mechanisms linking T gondii infection and schizophrenia remain unclear. Here we utilize a mouse model of chronic T gondii infection to identify protein biomarkers that are altered in serum and brain samples at 2 time points during chronic infection. Furthermore, we compare the identified biomarkers to those differing between "postmortem" brain samples from 35 schizophrenia patients and 33 healthy controls. Our findings suggest that T gondii infection causes substantial and widespread immune activation indicative of neural damage and reactive tissue repair in the animal model that partly overlaps with changes observed in the brains of schizophrenia patients. The overlapping changes include increases in C-reactive protein (CRP), interleukin-1 beta (IL-1β), interferon gamma (IFNγ), plasminogen activator inhibitor 1 (PAI-1), tissue inhibitor of metalloproteinases 1 (TIMP-1), and vascular cell adhesion molecule 1 (VCAM-1). Potential roles of these factors in the pathogenesis of schizophrenia and toxoplasmosis are discussed. Identifying a defined set of markers shared within the pathophysiological landscape of these diseases could be a key step towards understanding their specific contributions to pathogenesis. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  12. Experimental infection and detection of necrotizing hepatopancreatitis bacterium in the American lobster Homarus americanus.

    Science.gov (United States)

    Avila-Villa, Luz A; Gollas-Galván, Teresa; Martínez-Porchas, Marcel; Mendoza-Cano, Fernando; Hernández-López, Jorge

    2012-01-01

    Necrotizing hepatopancreatitis bacterium (NHPB) is an obligated intracellular bacteria causing severe hepatopancreatic damages and mass mortalities in penaeid shrimp. The worldwide distribution of penaeid shrimp as alien species threatens the life cycle of other crustacean species. The aim of the experiment was to evaluate the possibility of experimentally infecting the American lobster (Homarus americanus) with NHPB extracted from shrimp hepatopancreas. Homogenates from infected shrimp were fed by force to lobsters. Other group of lobsters was fed with homogenates of NHPB-free hepatopancreas. After the 15th day from initial inoculation, the presence of NHPB was detected by polymerase chain reaction in feces and hepatopancreas from lobsters inoculated with infected homogenates. Necrotized spots were observed in the surface of lobster hepatopancreas. In contrast, lobsters fed on NHPB-free homogenates resulted negative for NHPB. Evidence suggests the plasticity of NHPB which can infect crustacean from different species and inhabiting diverse latitudes. Considering the results, the American lobster could be a good candidate to maintain available NHPB in vivo.

  13. Experimental Infection and Detection of Necrotizing Hepatopancreatitis Bacterium in the American Lobster Homarus americanus

    Directory of Open Access Journals (Sweden)

    Luz A. Avila-Villa

    2012-01-01

    Full Text Available Necrotizing hepatopancreatitis bacterium (NHPB is an obligated intracellular bacteria causing severe hepatopancreatic damages and mass mortalities in penaeid shrimp. The worldwide distribution of penaeid shrimp as alien species threatens the life cycle of other crustacean species. The aim of the experiment was to evaluate the possibility of experimentally infecting the American lobster (Homarus americanus with NHPB extracted from shrimp hepatopancreas. Homogenates from infected shrimp were fed by force to lobsters. Other group of lobsters was fed with homogenates of NHPB-free hepatopancreas. After the 15th day from initial inoculation, the presence of NHPB was detected by polymerase chain reaction in feces and hepatopancreas from lobsters inoculated with infected homogenates. Necrotized spots were observed in the surface of lobster hepatopancreas. In contrast, lobsters fed on NHPB-free homogenates resulted negative for NHPB. Evidence suggests the plasticity of NHPB which can infect crustacean from different species and inhabiting diverse latitudes. Considering the results, the American lobster could be a good candidate to maintain available NHPB in vivo.

  14. Determination of IgG avidity in BALB/c mice experimentally infected with Toxocara canis.

    Science.gov (United States)

    Schoenardie, Elizandra Roselaine; Scaini, Carlos James; Avila, Luciana Farias da Costa de; Sperotto, Rita Leal; Borsuk, Sibele; Felicetti, Cristine Dias Pires; Pepe, Michele; Berne, Maria Elisabeth Aires

    2014-01-01

    Toxocariasis is a zoonotic disease in that IgM titers can remain high for long periods making difficult to determine the stage of the disease. The aim of this study is to investigate the applicability of indirect ELISA, associated with urea, to discriminate between the acute and chronic toxocariasis. IgG avidity was evaluated in 25 BALB/c mice experimentally infected with 1000 Toxocara canis eggs. Blood samples were collected, and sera treated with 6 M urea and assayed by ELISA every two weeks. The percent IgG avidity was determined using the mean absorbance of sera treated with urea, divided by the mean absorbance of untreated sera. In the first 15 days post-inoculation, was observed a low percentage, between 7.25 and 27.5%, IgG avidity, characteristic of an acute infection. After 60 days of infection, all the mice showed between 31.4 and 58% IgG avidity, indicating a chronic infection.

  15. Experimental Leishmania major infection suppresses HIV-1 DNA vaccine induced cellular immune response.

    Science.gov (United States)

    Robinson, Tara M; Nelson, Robin; Artis, David; Scott, Phillip; Boyer, Jean D

    2004-01-01

    The AIDS epidemic in the developing world represents a major global crisis and an effective vaccine is imperative. However, many parasites are common in developing countries and can result in a state of chronic immune activation that is polarized towards a Th2 profile and which can potentially impair responses to vaccines or other infectious challenges. In this study we demonstrate that experimental Leishmania major infection of BALB/c mice inhibits responses to a DNA-based HIV-1 gag vaccine. L. major infection in BALB/c results in a polarized Th2 immune response. In this study naïve BALB/c mice immunized with the HIV-1 gag DNA vaccine mounted a cellular immune response against the vaccine antigen, HIV-1 gag. CD8+ T lymphocytes were able to respond in vitro to HIV-1 gag stimulation and secrete interferon (IFN)-gamma. However, L. major-infected, vaccinated BALB/c mice had a significantly reduced number of IFN-gamma-producing CD8+ T cells following in vitro stimulation with gag antigen. These data suggest that parasitic infection, which results in a Th2 profile, reduces the efficacy of DNA vaccines that are designed to induce antiviral CD8+ T cell responses. Copyright 2004 S. Karger AG, Basel

  16. Allergy skin test responses during experimental infection with respiratory syncytial virus.

    Science.gov (United States)

    Skoner, David P; Gentile, Deborah A; Angelini, Betty; Doyle, William J

    2006-06-01

    Allergy skin testing is one of the most frequently performed physician office procedures. Many factors can affect the results of those tests, including the well-defined suppressive effect of systemic antihistamines. False-positive allergen skin test results are known to occur; however, contributing factors are not well understood. To determine whether a viral upper respiratory tract infection affects allergy skin test responsiveness. We performed skin tests with histamine and a panel of geographically relevant inhalant allergens on 16 adults before and 3, 6, and 21 days after experimental exposure to respiratory syncytial virus (RSV), a virus that causes signs and symptoms of a cold. The RSV exposure, with and without documented infection, caused increased wheal and flare areas to histamine and allergen and de novo positive allergen test responses in individuals with no measurable responses at baseline. These were noted as late as 21 days after RSV exposure and may be consistent with mediation by up-regulated neurogenic inflammation during RSV infection. These results may have implications for explaining the cause of such well-known complications of RSV infection as otitis media, bronchiolitis, and asthmatic exacerbation.

  17. The Effect of Marshallagia marshalli on Serum Gastrin Concentrations in Experimentally Infected Lambs.

    Science.gov (United States)

    Moradpour, Nona; Borji, Hassan; Razmi, Gholamreza; Maleki, Mohsen; Kazemi, Hossein

    2016-08-01

    :  Because there appeared to be no data available on serum gastrin concentrations in animals infected with Marshallagia marshalli, and considering the high prevalence of this parasite in livestock throughout many countries, we decided to perform research in the field using experimental infection. After surgical implantation of abomasal cannula into 10 male Baluchi sheep, each animal was orally infected with 5,000 M. marshalli larvae. Serum gastrin concentrations and abomasal pH were measured with a human ELISA kit and a PHM LE438 standard pH electrode, respectively. According to the results obtained from the study, serum gastrin increased after 14 and 21 days post-infection (dpi), while abomasal pH increased after 7 dpi and reached a maximal value 16 dpi. The increase in serum gastrin concentration was revealed 6 days after elevation in abomasal pH, which could be the result of reduced acid secretion. Generally, the present study pointed out that a limited number of M. marshalli could increase serum gastrin concentrations.

  18. Efficacy of clorsulon for the treatment of experimentally induced infections of Fasciola hepatica in goats.

    Science.gov (United States)

    Sundlof, S F; Bliss, E L; Greiner, E C; Tran, T Q; Wertenberger, M A

    1991-01-01

    A dose titration study was undertaken to determine the efficacy of clorsulon against the adult stage of Fasciola hepatica in goats. Thirty-nine goats were experimentally infected with metacercariae of F hepatica. At 14 weeks after infection, each goat was assigned randomly to 1 of 5 groups. Goats in groups 1 to 4 received a single oral administration of clorsulon at dosages of 3.5, 7, 11, and 15 mg/kg of body weight, respectively. The fifth group of goats (control group) was infected with F hepatica, but were not treated with clorsulon. Postmortem examination of goats at 3 weeks after treatment revealed mean reductions in numbers of flukes of 83, 98, 99, and 100% for groups 1 to 4, respectively. Mean percentage of reduction in eggs following treatment of groups was 82, 98, 100, and 100%, respectively. The clinical effects of clorsulon in 24 goats that were not infected with F hepatica were studied. Goats in groups 1 to 3 received a single oral administration of clorsulon at dosages of 7, 21, and 35 mg/kg, respectively, every other day for a total of 3 doses/goat. Group-4 goats (control group) received a vehicle placebo. Goats in group 3 were subject to postmortem examination at 14 days after dosing. Abnormal signs or lesions that could be attributed to clorsulon were not found in any goat.

  19. Effect of wide spectrum anti-helminthic drugs upon Schistosoma mansoni experimentally infected mice

    Directory of Open Access Journals (Sweden)

    PANCERA Christiane Finardi

    1997-01-01

    Full Text Available Mebendazole, albendazole, levamisole and thiabendazole are well known as active drugs against several nematode species, and against cestodes as well, when the first two drugs are considered. None of the drugs have proven activity, however, against trematodes. We tested the effect of these drugs on the fecal shedding of schistosome eggs and the recovering of adult schistosomes, after portal perfusion in Schistosoma mansoni experimentally infected mice. Balb/c mice infected with 80 S. mansoni cercariae were divided into three groups, each in turn subdivided into four other groups, for each tested drug. The first group was treated with each one of the studied drugs 25 days after S. mansoni infection; the second group was submitted to treatment with each one of the drugs 60 days after infection. Finally, the third group, considered as control, received no treatment. No effect upon fecal shedding of S. mansoni eggs and recovering of schistosomes after portal perfusion was observed when mice were treated with either mebendazole or albendazole. Mice treated with either levamisole or thiabendazole, on the other hand, showed a significant reduction in the recovering of adult schistosomes after portal perfusion, mainly when both drugs were given during the schistosomula evolution period, i.e., 25 days after cercariae penetration, probably due to unspecific immunomodulation

  20. Aspects of resistance to experimental infection with Trypanosoma cruzi; Aspectos da resistencia a infecao experimental com Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Viviane Liotti

    2010-07-01

    Chagas disease, a zoonosis caused by the protozoan Trypanosoma cruzi, has a wide distribution in Latin America and extends from the southern part of the United States to Argentina. A number of 10 million of infected people is estimated and another 25 million exposed to the risk. Although discovered over a century, Chagas disease is still a serious infection that causes great socioeconomic impact, with no effective treatment at the chronic phase and in which, a lack of scientific knowledge can be observed. The main goal of this work was that obtaining and using consomic strain of mice, the resistance could be investigated. Consomic strains were produced by programmed mating, in which the animals were monitored with DNA polymorphic markers, and one of his chromosomes was replaced by his homologue from another strain. As parental, were used, the inbred strains C57BL/6/J Unib with resistant phenotype (donor) and as receiver, the A/JUnib strain, that has a susceptible phenotype. These models were used to produce five consomic strains: for the chromosomes 7 (CSs7), 11 (CSs11), 14 (CSs14), 17 (CSs17) and 19 (CSs19), described by Passos et al. (2003) as important in controlling infection caused by the Y strain of T. cruzi. In experimental testing, the consomics were inoculated intraperitoneally at doses of 10{sup 1}, 10{sup 2}, 10{sup 3} and 10{sup 4} using as control, animals from both parental lines. In all consomics, resistance was higher than that observed in the susceptible parental. In a second protocol, the consomics were mated with scheduled associations and the progenies were challenged with inocula employing increasing doses of trypomastigotes. The resistance observed in this group was also higher than that observed in the parental with susceptible phenotype. The observed results demonstrate that the use of the consomic strains that were produced order to assess the contribution of each chromosome in the resistance, as well as the effects of association between

  1. Experimental Investigation on the Specific Heat of Carbonized Phenolic Resin-Based Ablative Materials

    Science.gov (United States)

    Zhao, Te; Ye, Hong; Zhang, Lisong; Cai, Qilin

    2017-10-01

    As typical phenolic resin-based ablative materials, the high silica/phenolic and carbon/phenolic composites are widely used in aerospace field. The specific heat of the carbonized ablators after ablation is an important thermophysical parameter in the process of heat transfer, but it is rarely reported. In this investigation, the carbonized samples of the high silica/phenolic and carbon/phenolic were obtained through carbonization experiments, and the specific heat of the carbonized samples was determined by a 3D DSC from 150 °C to 970 °C. Structural and compositional characterizations were performed to determine the mass fractions of the fiber and the carbonized product of phenolic which are the two constituents of the carbonized samples, while the specific heat of each constituent was also measured by 3D DSC. The masses of the carbonized samples were reduced when heated to a high temperature in the specific heat measurements, due to the thermal degradation of the carbonized product of phenolic resin in the carbonized samples. The raw experimental specific heat of the two carbonized samples and the carbonized product of phenolic resin was modified according to the quality changes of the carbonized samples presented by TGA results. Based on the mass fraction and the specific heat of each constituent, a weighted average method was adopted to obtain the calculated results of the carbonized samples. Due to the unconsolidated property of the fiber samples which impacts the reliability of the DSC measurement, there is a certain deviation between the experimental and calculated results of the carbonized samples. Considering the similarity of composition and structure, the data of quartz glass and graphite were used to substitute the specific heat of the high silica fiber and carbon fiber, respectively, resulting in better agreements with the experimental ones. Furthermore, the accurate specific heat of the high silica fiber and carbon fiber bundles was obtained by

  2. Prevalence of specific IGM due to toxoplasma, rubella, CMV and c.trachomatis infections during pregnancy

    Directory of Open Access Journals (Sweden)

    Yasodhara P

    2001-01-01

    Full Text Available One hundred and seventy five apparently normal asymptomatic pregnant women were studied prospectively and 247 women with different complications of pregnancy were screened at the time of delivery for infections like Chlamydia trachomatis, Toxoplasma, Rubella and cytomegalovirus (CMV. One hundred and forty two women with normal outcome of pregnancy served as controls. Specific IgM due to these agents were determined in the sera using commercial diagnostic kits. Results of the study showed that chlamydial infection was the most prevalent (29.8% followed by Toxoplasmosis (13.1, Rubella (6.5% and CMV (5.8%. Adverse outcome was seen among those seropositive for Chlamydia, Toxoplasmosis and Rubella. CMV showed no association with adverse outcome of pregnancy. Since Chlamydia and Toxoplasmosis are amenable to treatment with antibiotics, screening for these infections and appropriate treatment would improve outcome of pregnancy.

  3. Humans with chimpanzee-like major histocompatibility complex-specificities control HIV-1 infection

    DEFF Research Database (Denmark)

    Hoof, Ilka; Kesmir, Can; Lund, Ole

    2008-01-01

    Background: Major histocompatibility complex (MHC) class I molecules allow immune surveillance by presenting a snapshot of the intracellular state of a cell to circulating cytotoxic T lymphocytes. The MHC class I alleles of an HIV-1 infected individual strongly influence the level of viremia...... and the progression rate to AIDS. Chimpanzees control HIV-1 viral replication and develop a chronic infection without progressing to AIDS. A similar course of disease is observed in human long-term non-progressors. Objective: To investigate if long-term non-progressors and chimpanzees have functional similarities...... in their MHC class I repertoire. Methods: We compared the specificity of groups of human MHC molecules associated with different levels of viremia in HIV-1 infected individuals with those of chimpanzee. Results and conclusion: We demonstrate that human MHC with control of HIV-1 viral load share binding motifs...

  4. High-Dose Borna Disease Virus Infection Induces a Nucleoprotein-Specific Cytotoxic T-Lymphocyte Response and Prevention of Immunopathology†

    Science.gov (United States)

    Furrer, Esther; Bilzer, Thomas; Stitz, Lothar; Planz, Oliver

    2001-01-01

    Experimental Borna disease virus (BDV) infection of rats and natural infection of horses and sheep leads to severe central nervous system disease based on immunopathological pathways. The virus replicates slowly, and the cellular immune response results in immunopathology. CD8+ T cells exert effector cell functions, and their activity results in the destruction of virus-infected cells. Previously, Oldach and colleagues (D. Oldach, M. C. Zink, J. M. Pyper, S. Herzog, R. Rott, O. Narayan, and J. E. Clements, Virology 206:426–434, 1995) have reported protection against Borna disease after inoculation of high-dose cell-adapted BDV. Here we show that the outcome of the infection, i.e., immunopathology versus protection, is simply dependent on the amount of virus used for infection. High-dose BDV (106 FFU) triggers an early virus-specific reaction of the immune system, as demonstrated by strong cellular and humoral responses. In particular, the early presence and function of nucleoprotein-specific CD8+ T cells could be demonstrated in the brain. We present evidence that in a noncytolytic and usually persistent virus infection, high-dose input virus mediates early control of the pathogen due to an efficient induction of an antiviral immune mechanism. From these data, we conclude that immune reactivity, in particular the cytotoxic T-cell response, determines whether the virus is controlled with prevention of the ensuing immunopathological disease or whether a persistent infection is established. PMID:11689651

  5. Platelet parameters in children with upper urinary tract infection: is there a specific response?

    Science.gov (United States)

    Catal, F; Bavbek, N; Bayrak, O; Uz, E; Isik, B; Karabel, M; Degirmencioglu, H; Mete, E; Akcay, A

    2008-01-01

    Although complete blood count is routinely ordered in most upper urinary tract infections (UTI), and information regarding the patient's platelet indices is made available without added cost, the relationship between platelet count and mean platelet volume (MPV) and specific platelet responses to different infectious agents has not been extensively characterized in UTI. The objectives of this study were to examine platelet counts and platelet indices in children with culture-proven upper UTI to determine if there are organism-specific platelet responses. A retrospective analysis of data from all pediatric urine samples processed at Fatih University Medical School microbiology laboratory was undertaken for a period of two years (January 1, 2005, to December 31, 2006). Of the 200 patients with positive urine cultures, 146 (73%) were infected with gram-negative bacteria and 54 (27%) grew gram-positive bacteria. The platelet count during the episode of upper UTI and the incidence of thrombocytosis was significantly higher with the gram-positive infections than with the gram-negative infections or controls (p < 0.05). A statistically significant higher MPV was detected in the subjects with upper UTI (p < 0.05). Also, our data showed a statistically significant increase in MPV with gram-positive infections compared with the other groups (p < 0.05). In conclusion, based on the importance of the hemostatic component in the pathophysiology of infections, our findings of platelet count and MPV and predictivity of the type of the organism would suggest the usefulness of the routine measurements in children with upper UTI.

  6. Experimental therapeutic studies of Solanum aculeastrum Dunal. on Leishmania major infection in BALB/c mice.

    Science.gov (United States)

    Laban, Linet T; Anjili, Christopher O; Mutiso, Joshua M; Ingonga, Johnstone; Kiige, Samuel G; Ngedzo, Mgala M; Gicheru, Michael M

    2015-01-01

    Solanum acueastrum Dunal. has been shown to have some chemotherapeutic value. Leaf and berry water and methanol compounds of S. acueastrum were evaluated for possible antileishmanial activity In vivo on BALB/c mice and in vitro against Leishmania major promastigotes, amastigotes and vero cells. Dry S. aculeastrum berry and leaf material were extracted in methanol and water. L. major parasites were exposed to different concentrations of S. aculeastrum fruit and leaf compounds and the IC50 on the promastigotes, percentage of infection rate of macrophages by amastigotes and the toxicological effect on vero cells were determined. BALB/c mice were infected subcutaneously with 1×10(6) promastigotes and kept for four weeks to allow for disease establishment. Infected mice were treated with fruit and leaf methanolic and water compounds, amphotericin B (AmB), and sterile phosphate buffered saline (PBS). Fruit methanol compound was most effective in inhibiting the growth of promastigotes with IC5078.62 μg/ml. Fruit water compound showed the best activity in inhibiting infection of macrophages by amastigotes. Fruit methanol compound was more toxic at Ld50=8.06 mg/ml to vero cells than amphotericin B. Analysis of variance computation indicated statistically significant difference in lesion sizes between experimental and control mice groups (P=0.0001). Splenic impression smears ANOVA indicated a highly significant difference in parasitic numbers between the experimental and the control groups (P=0.0001). The results demonstrate that compounds from S. aculeastrum have potential anti-leishmanial activities and the medicinal use of the plant poses considerable toxicity against dividing vero cells.

  7. Experimental infection of South American camelids with bluetongue virus serotype 8.

    Science.gov (United States)

    Schulz, Claudia; Eschbaumer, Michael; Rudolf, Miriam; König, Patricia; Keller, Markus; Bauer, Christian; Gauly, Matthias; Grevelding, Christoph G; Beer, Martin; Hoffmann, Bernd

    2012-01-27

    Bluetongue (BT) is an infectious, non-contagious disease of wild and domestic ruminants. It is caused by bluetongue virus (BTV) and transmitted by Culicoides biting midges. Since 1998, BT has been emerging throughout Europe, threatening not only the naïve ruminant population. Historically, South American camelids (SAC) were considered to be resistant to BT disease. However, recent fatalities related to BTV in captive SAC have raised questions about their role in BTV epidemiology. Data on the susceptibility of SAC to experimental infection with BTV serotype 8 (BTV-8) were collected in an animal experiment. Three alpacas (Vicugna pacos) and three llamas (Lama glama) were experimentally infected with BTV-8. They displayed very mild clinical signs. Seroconversion was first measured 6-8 days after infection (dpi) by ELISA, and neutralising antibodies appeared 10-13 dpi. BTV-8 RNA levels in blood were very low, and quickly cleared after seroconversion. However, spleens collected post-mortem were still positive for BTV RNA, over 71 days after the last detection in blood samples. Virus isolation was only possible from blood samples of two alpacas by inoculation of highly sensitive interferon alpha/beta receptor-deficient (IFNAR(-/-)) mice. An in vitro experiment demonstrated that significantly lower amounts of BTV-8 adsorb to SAC blood cells than to bovine blood cells. Although this experiment showed that SAC are generally susceptible to a BTV-8 infection, it indicates that these species play a negligible role in BTV epidemiology. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Immuno-pathological studies on broiler chicken experimentally infected with Escherichia coli and supplemented with neem (Azadirachta indica leaf extract

    Directory of Open Access Journals (Sweden)

    Vikash Sharma

    2016-07-01

    Full Text Available Aim: The present study was conducted to evaluate the effects of neem leaf extract (NLE supplementation on immunological response and pathology of different lymphoid organs in experimentally Escherichia coli challenged broiler chickens. Materials and Methods: For this study, we procured 192-day-old broiler chicks from local hatchery and divided them into Groups A and Group B containing 96 birds each on the first day. Chicks of Group A were supplemented with 10% NLE in water, whereas chicks of Group B were not supplemented with NLE throughout the experiment. At 7th day of age, chicks of Group A were divided into A1 and A2 and Group B into B1 and B2 with 54 and 42 chicks, respectively, and chicks of Groups A1 and B1 were injected with E. coli O78 at 107 colony-forming units/0.5 ml intraperitoneally. Six chicks from each group were sacrificed at 0, 2, 4, 7, 14, 21, and 28 days post infection; blood was collected and thorough post-mortem examination was conducted. Tissue pieces of spleen and bursa of Fabricius were collected in 10% buffered formalin for histopathological examination. Serum was separated for immunological studies. Result: E. coli specific antibody titer was significantly higher in Group A1 in comparison to Group B1. Delayed-type hypersensitivity response against 2,4 dinirochlorobenzene (DNCB antigen was significantly higher in Group A1 as compared to Group B1. Pathological studies revealed that E. coli infection caused depletion of lymphocytes in bursa of Fabricius and spleen. Severity of lesions in Group A1 was significantly lower in comparison to Group B1. Conclusion: 10% NLE supplementation enhanced the humoral as well as cellular immune responses attributed to its immunomodulatory property in experimentally E. coli infected broiler chicken.

  9. Comparison of Abortion and Infection after Experimental Challenge of Pregnant Bison and Cattle with Brucella abortus Strain 2308▿

    Science.gov (United States)

    Olsen, S. C.; Johnson, C.

    2011-01-01

    A comparative study was conducted using data from naive bison (n = 45) and cattle (n = 46) from 8 and 6 studies, respectively, in which a standardized Brucella abortus strain 2308 experimental challenge was administered during midgestation. The incidence of abortion, fetal infection, uterine or mammary infection, or infection in maternal tissues after experimental challenge was greater (P abort, the time between experimental challenge and abortion was shorter (P abortion did not differ (P > 0.05) between cattle and bison. The results of our study suggest that naive bison and cattle have similarities and differences after experimental exposure to a virulent B. abortus strain. Although our data suggest that bison may be more susceptible to infection with Brucella, some pathogenic characteristics of brucellosis were similar between bison and cattle. PMID:21976222

  10. INVOLVEMENT OF BACTERICIDAL FACTORS FROM THROMBIN-STIMULATED PLATELETS IN CLEARANCE OF ADHERENT VIRIDANS STREPTOCOCCI IN EXPERIMENTAL INFECTIVE ENDOCARDITIS

    NARCIS (Netherlands)

    VANDERWERFF, J; ZAAT, SAJ; JOLDERSMA, W; HESS, J

    Platelets activated with thrombin release bactericidal factors. We studied the role of the susceptibility of viridans streptococci to these bactericidal factors in the development of infective endocarditis (IE). By using the experimental endocarditis rabbit model, the initial adherence and the

  11. Epidemiology of pathogen-specific respiratory infections among three US populations.

    Directory of Open Access Journals (Sweden)

    Jennifer M Radin

    Full Text Available Diagnostic tests for respiratory infections can be costly and time-consuming. Improved characterization of specific respiratory pathogens by identifying frequent signs, symptoms and demographic characteristics, along with improving our understanding of coinfection rates and seasonality, may improve treatment and prevention measures.Febrile respiratory illness (FRI and severe acute respiratory infection (SARI surveillance was conducted from October 2011 through March 2013 among three US populations: civilians near the US-Mexico border, Department of Defense (DoD beneficiaries, and military recruits. Clinical and demographic questionnaire data and respiratory swabs were collected from participants, tested by PCR for nine different respiratory pathogens and summarized. Age stratified characteristics of civilians positive for influenza and recruits positive for rhinovirus were compared to other and no/unknown pathogen. Seasonality and coinfection rates were also described.A total of 1444 patients met the FRI or SARI case definition and were enrolled in this study. Influenza signs and symptoms varied across age groups of civilians. Recruits with rhinovirus had higher percentages of pneumonia, cough, shortness of breath, congestion, cough, less fever and longer time to seeking care and were more likely to be male compared to those in the no/unknown pathogen group. Coinfections were found in 6% of all FRI/SARI cases tested and were most frequently seen among children and with rhinovirus infections. Clear seasonal trends were identified for influenza, rhinovirus, and respiratory syncytial virus.The age-stratified clinical characteristics associated with influenza suggest that age-specific case definitions may improve influenza surveillance and identification. Improving identification of rhinoviruses, the most frequent respiratory infection among recruits, may be useful for separating out contagious individuals, especially when larger outbreaks occur

  12. Envelope-specific antibodies and antibody-derived molecules for treating and curing HIV infection

    Science.gov (United States)

    Ferrari, Guido; Haynes, Barton F.; Koenig, Scott; Nordstrom, Jeffrey L.; Margolis, David M.; Tomaras, Georgia D.

    2017-01-01

    HIV-1 is a retrovirus that integrates into host chromatin and can remain transcriptionally quiescent in a pool of immune cells. This characteristic enables HIV-1 to evade both host immune responses and antiretroviral drugs, leading to persistent infection. Upon reactivation of proviral gene expression, HIV-1 envelope (HIV-1 Env) glycoproteins are expressed on the cell surface, transforming latently infected cells into targets for HIV-1 Env-specific monoclonal antibodies (mAbs), which can engage immune effector cells to kill productively infected CD4+ T cells and thus limit the spread of progeny virus. Recent innovations in antibody engineering have resulted in novel immunotherapeutics such as bispecific dual-affinity re-targeting (DART) molecules and other bi- and trispecific antibody designs that can recognize HIV-1 Env and recruit cytotoxic effector cells to kill CD4+ T cells latently infected with HIV‑1. Here, we review these immunotherapies, which are designed with the goal of curing HIV-1 infection. PMID:27725635

  13. Antigen-Specific IP-10 Release Is a Sensitive Biomarker of Mycobacterium bovis Infection in Cattle.

    Directory of Open Access Journals (Sweden)

    Sven D C Parsons

    Full Text Available The most widely used ante-mortem diagnostic tests for tuberculosis in cattle are the tuberculin skin test and the interferon-gamma (IFN-γ release assay, both of which measure cell-mediated immune responses to Mycobacterium bovis infection. However, limitations in the performance of these tests results in a failure to identify all infected animals. In attempting to increase the range of diagnostic tests for tuberculosis, measurement of the cytokine IP-10 in antigen-stimulated blood has previously been shown to improve the detection of M. tuberculosis and M. bovis infection, in humans and African buffaloes (Syncerus caffer, respectively. In the present study, 60 cattle were identified by the single intradermal comparative tuberculin test as tuberculosis reactors (n = 24 or non-reactors (n = 36 and the release of IFN-γ and IP-10 in antigen-stimulated whole blood from these animals was measured using bovine specific ELISAs. There was a strong correlation between IP-10 and IFN-γ production in these samples. Moreover, measurement of the differential release of IP-10 in response to stimulation with M. bovis purified protein derivative (PPD and M. avium PPD distinguished between reactor and non-reactor cattle with a sensitivity of 100% (95% CI, 86%-100% and a specificity of 97% (95% CI, 85%-100%. These results suggest that IP-10 might prove valuable as a diagnostic biomarker of M. bovis infection in cattle.

  14. Natural Schistosoma mansoni infection in Nectomys squamipes: histopathological and morphometric analysis in comparison to experimentally infected N. squamipes and C3H/He mice

    Directory of Open Access Journals (Sweden)

    Michele Costa-Silva

    2002-10-01

    Full Text Available Histopathologic and morphometric (area, perimeter, major and minor diameters analysis of hepatic granulomas isolated from twelve naturally infected Nectomys squamipes were compared to four experimentally infected ones and six C3H/He mice. Liver paraffin sections were stained for cells and extracellular matrix. Both groups of N. squamipes presented peculiar granulomas consisting predominantly of large macrophages, full of schistosome pigment, characterizing an exudative-macrophage granuloma type, smaller than the equivalent granuloma type in mouse. Naturally infected animals exhibited granulomas in different stages of development, including large number of involutional types. Morphometric analysis showed that all measurements were smaller in naturally infected animals than in other groups. The results demonstrated that both N. squamipes groups reproduced, with small variations, the hepatic granuloma aspects already described in cricetidium (Calomys callosus, showing a genetic tendency to set up strong macrophage responses and small granulomas. Unexpectedly, natural infection did not engender distinguished histopathological characteristics distinct from those derived from experimental single infection, showing changes predominantly secondary to the duration of infection. It appears that the variability of the inocula (and the number of infections? interfere more with the quantity than with the quality of the pathological changes, denoting some morpho-functional determinism in the response to schistosomal infection dependent on the animal species.

  15. Comparative efficacy of tulathromycin and tildipirosin for the treatment of experimental Mycoplasma bovis infection in calves

    OpenAIRE

    Bartram, David J.; Moyaert, Hilde; Vanimisetti, Bindu H.; Ramage, Clifford P.; Reddick, David; Stegemann, Michael R

    2016-01-01

    Abstract The objective of this negative controlled, blinded, randomised, parallel group study was to compare the efficacy of two injectable macrolide antimicrobials, tulathromycin and tildipirosin, administered by single subcutaneous injection at dose rates of 2.5 and 4.0 mg kg−1 bodyweight, respectively, in the treatment of an experimentally induced Mycoplasma bovis infection in calves. A total of 238 M. bovis‐negative calves were challenged on three consecutive days with M. bovis by endobro...

  16. Recovery of Dengue Viruses from Tissues of Experimentally Infected Rhesus Monkeys

    Science.gov (United States)

    Marchette, Nyven J.; Halstead, Scott B.; Nash, Donald R.; Stenhouse, Andrew C.

    1972-01-01

    A tissue explant culture technique for the recovery of dengue virus from experimentally infected monkey tissue is described and compared with tissue culture assay of tissue triturates and co-cultivation of trypsinized cells in cell cultures. The most efficient technique was one in which minced tissue was explanted in co-culture with dengue virus-susceptible LLC-MK2 monkey kidney cells. This technique shows promise of being useful for detection of virus in autopsy material from fatal dengue hemorrhagic fever cases. PMID:4627963

  17. The pathology of experimental Schistosoma curassoni infections in mice and hamsters.

    Science.gov (United States)

    Vercruysse, J; Fransen, J; Southgate, V R; Rollinson, D

    1986-11-01

    The histopathology of experimental Schistosoma curassoni infections in white mice and hamsters was studied. In mice, hepatic lesions were severe with characteristic extensive perilobular fibrosis and large perilobular granulomas throughout the parenchyma. Only a few granulomas were detected in the lung, small intestine, and rectum of mice. In hamsters, lesions in the liver were limited. Few granulomas were found but the giant cell reaction was pronounced. Lesions in the lung and small intestine were minimal. Many subserosal and submucosal epithelioid cell granulomas were in the colon and rectum of hamsters. Parasites were not detected in the bladder of either mice or hamsters.

  18. Site-specific gene expression analysis of implant-near cells in a soft tissue infection model - Application of laser microdissection to study biomaterial-associated infection.

    Science.gov (United States)

    Svensson, Sara; Trobos, Margarita; Omar, Omar; Thomsen, Peter

    2017-08-01

    Analysis of the implant-tissue interface is important for an understanding of the cellular response to biomaterials with different surface characteristics. However, inaccessibility to the site has restricted the detailed evaluation of the tissue surrounding the implant. Laser microdissection enables the isolation of specific cells and tissues for subsequent DNA, RNA, or protein analysis. The present experimental study employed laser microdissection to analyze tissue-specific differences in gene expression in cells around infected or control titanium implants 72 h after subcutaneous implantation in a rat model. Three different tissue zones located 0-800 μm away from the implant-tissue interface were analyzed. Implant sites challenged with a dose of 106  CFU Staphylococcus epidermidis demonstrated higher gene expression of selected markers for inflammation (TNF-α, IL-6), cell recruitment (MCP-1, IL-8, IL-8 R), infection (TLR2), and tissue remodeling (MMP-9) compared with control implants. Furthermore, the gene expression analysis of the three extracted tissue zones revealed marked spatial differences, depending on the distance to the implant. Control implants continuously induced higher cell gene expression in the implant-tissue interface compared with cells 200-800 μm away from the implant, whereas the sites inoculated with S. epidermidis resulted in high gene expression further away from the implant as well. In conclusion, this study demonstrates that laser microdissection is an interesting tool, revealing both gene- and site-specific gene expression patterns in the implant-tissue interface. The technique provides an opportunity for detailed molecular dissection of the biological events related to the implant but occurring at different distances from the implant. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2210-2217, 2017. © 2017 Wiley Periodicals, Inc.

  19. EXPERIMENTAL INFECTION BY Trypanosoma vivax IN GOATS INFECÇÃO EXPERIMENTAL EM CAPRINOS COM Trypanosoma vivax

    Directory of Open Access Journals (Sweden)

    Francisco David Nascimento Sousa

    2008-10-01

    Full Text Available

    Four goats were infected intravenously with 1.0 mL of cattle blood containing about 1.25 x 105 Trypanosoma vivax derived from spontaneous outbreak in cattle at Catolé do Rocha city, Paraíba, Brazil. Other four goats were used as controls. Parasitemia and body temperature were determined daily for 40 days. Animals were weighted each 7 days, and blood samples for blood cells counts were collected each 5 days. It was obtained a sample of liquor from each animal before death; cerebrospinal fluid samples were submitted to biochemical and cytological evaluations, density determination and parasite detection. A positive correlation was found between body temperature and parasitemia in infected animals. These animals presented anemia, leukopenia, hypoglycemia, decreased serum levels of total proteins and cholesterol, and nervous symptoms. Examination of cerebrospinal fluid resulted in decrease of glucose levels and increase in lactate dehydrogenase, cell counts and presence of the parasite. At necropsy it was found pale carcass, generalized infartation of lymphonodes, pulmonary edema, and liquid accumulation of pericardium. Histological changes were characterized by interstitial pneumonia, miocarditis, cardiac fibrosis, meningitis, and encephalitis. All observed changes confirm patogenicity of T. vivax.

    KEY WORDS: Experimental infection, trypanosomiasis, patogenicity.

    Quatro caprinos foram infectados experimentalmente por via intravenosa com 1,0 ml de sangue contendo aproximadamente 1,25 x 105 tripanossomas/ml, utilizando-se um isolado de Trypanosoma vivax de bovinos infectados naturalmente no município de Catolé do Rocha, Paraíba. A parasitemia e a temperatura foram determinadas diariamente durante quarenta dias. A cada cinco dias realizaram-se coletas de sangue para hemograma e análise bioquímica sérica. Antes do

  20. Longevity and composition of cellular immune responses following experimental Plasmodium falciparum malaria infection in humans.

    Directory of Open Access Journals (Sweden)

    Anne C Teirlinck

    2011-12-01

    Full Text Available Cellular responses to Plasmodium falciparum parasites, in particular interferon-gamma (IFNγ production, play an important role in anti-malarial immunity. However, clinical immunity to malaria develops slowly amongst naturally exposed populations, the dynamics of cellular responses in relation to exposure are difficult to study and data about the persistence of such responses are controversial. Here we assess the longevity and composition of cellular immune responses following experimental malaria infection in human volunteers. We conducted a longitudinal study of cellular immunological responses to sporozoites (PfSpz and asexual blood-stage (PfRBC malaria parasites in naïve human volunteers undergoing single (n = 5 or multiple (n = 10 experimental P. falciparum infections under highly controlled conditions. IFNγ and interleukin-2 (IL-2 responses following in vitro re-stimulation were measured by flow-cytometry prior to, during and more than one year post infection. We show that cellular responses to both PfSpz and PfRBC are induced and remain almost undiminished up to 14 months after even a single malaria episode. Remarkably, not only 'adaptive' but also 'innate' lymphocyte subsets contribute to the increased IFNγ response, including αβT cells, γδT cells and NK cells. Furthermore, results from depletion and autologous recombination experiments of lymphocyte subsets suggest that immunological memory for PfRBC is carried within both the αβT cells and γδT compartments. Indeed, the majority of cytokine producing T lymphocytes express an CD45RO(+ CD62L(- effector memory (EM phenotype both early and late post infection. Finally, we demonstrate that malaria infection induces and maintains polyfunctional (IFNγ(+IL-2(+ EM responses against both PfRBC and PfSpz, previously found to be associated with protection. These data demonstrate that cellular responses can be readily induced and are long-lived following infection with P

  1. Establishment of macrocyclic lactone resistant Dirofilaria immitis isolates in experimentally infected laboratory dogs.

    Science.gov (United States)

    Pulaski, Cassan N; Malone, John B; Bourguinat, Catherine; Prichard, Roger; Geary, Timothy; Ward, Danielle; Klei, Thomas R; Guidry, Tal; Smith, George 'Bud'; Delcambre, Brooke; Bova, Jonathan; Pepping, Jenny; Carmichael, James; Schenker, Rudolf; Pariaut, Romain

    2014-11-07

    Strains of Dirofilaria immitis suspected of lack of efficacy (LOE) to macrocyclic lactone (ML) preventive drugs have been increasingly reported in dogs by practicing veterinarians since 2005 in the Lower Mississippi Delta region. If proven, and not controlled in the early stages, the emergence of ML drug resistance threatens to become a widespread problem in the US that may limit the effectiveness of current preventive drug treatment methods. To validate practice reports, a statewide survey of Louisiana veterinarians was done to define the extent of the problem and identify focal 'hotspots' of reported ML LOEs using Geographic Information Systems (GIS) methods. The present study then utilized microfilariae (Mf) from two canine field cases from different state locations that fit criteria for a high index of suspicion of LOE against heartworms by ML drugs. Blood containing Mf from the canine field cases was used to infect and produce L3 in Aedes aegypti for experimental infection of two groups of dogs, each of which contained two laboratory dogs, one treated with prophylactic ivermectin (12 μg/kg) monthly for 6 months at twice the label dose (6 μg/kg), and one untreated control. Both treated and untreated dogs from Group I and Group II developed patent D. immitis infections by 218 DPI and 189 DPI, respectively, as evidenced by a positive occult heartworm antigen test and microfilaremia by the Knott's test. Mf counts gradually increased post-patency in test and control dogs. Infective larvae raised from microfilariae from the treated Group I dog were used to successfully establish a second generation isolate, confirming heritability of resistance in the face of a monthly ivermectin challenge dose of 24 μg/kg, given monthly for 3 months. These experimental infection studies provide in vivo evidence of the existence of ML drug resistance in dogs infected by D. immitis L3 from suspect field LOE cases in the Lower Mississippi Delta. Results encourage further work on

  2. Pulmonary responses to pathogen-specific antigens in latent Mycobacterium tuberculosis infection.

    Science.gov (United States)

    Jarvela, Jessica R; Tuscano, Lori; Lee, Hung; Silver, Richard F

    2016-01-01

    In this study, we used ELISPOT to quantify frequencies of bronchoalveolar lavage (BAL) and peripheral blood T cells capable of producing IFNγ in response to PPD, antigen 85B, and Mtb-specific antigens CFP-10 and ESAT-6 in individuals with latent tuberculosis infection (LTBI) and Mtb-naïve controls. Compared to peripheral blood, BAL cells of LTBI subjects displayed significant enrichment for T cells responding to PPD, antigen 85B, and CFP-10, but not to ESAT-6. Baseline BAL cells of LTBI subjects displayed significant production of Mig (CXCL9) in response to PPD, antigen 85B, and CFP-10 as well. These findings suggest that enrichment for Mtb-specific T cells within BAL is not unique to active pulmonary tuberculosis and may, to the contrary, contribute to protection from re-infection in Mtb immune individuals. Published by Elsevier Ltd.

  3. Comparison of abortion and infection after experimental challenge of pregnant bison and cattle with Brucella abortus strain 2308

    Science.gov (United States)

    A comparative study was conducted using data from naive bison (n=45) and cattle (n=46) from 8 and 6 studies, respectively, in which a standardized Brucella abortus strain 2308 experimental challenge was administered. The incidence of abortion, fetal infection, uterine or mammary infection, or infec...

  4. Differences in intermittent and continuous fecal shedding patterns between natural and experimental Mycobacterium avium subspecies paratuberculosis infections in cattle

    Science.gov (United States)

    The objective of this paper is to study shedding patterns of cows infected with Mycobacterium avium subsp. paratuberculosis (MAP). While multiple single farm studies of MAP dynamics were reported, there is not large-scale meta-analysis of both natural and experimental infections. Large difference...

  5. Experimental infection of highly pathogenic avian influenza virus H5N1 in black-headed gulls (Chroicocephalus ridibundus)

    NARCIS (Netherlands)

    A. Ramis (Antonio); G. van Amerongen (Geert); M.W.G. van de Bildt (Marco); L.M.E. Leijten (Lonneke); R. Vanderstichel (R.); A.D.M.E. Osterhaus (Albert); T. Kuiken (Thijs)

    2014-01-01

    textabstractHistorically, highly pathogenic avian influenza viruses (HPAIV) rarely resulted in infection or clinical disease in wild birds. However, since 2002, disease and mortality from natural HPAIV H5N1 infection have been observed in wild birds including gulls. We performed an experimental

  6. Diagnosis of the strongyloid nematode Strongyloides venezuelensis in experimentally infected rats.

    Science.gov (United States)

    Marques, P D; Malta, F M; Meisel, D M C L; Corral, M A; Pinho, J R; Costa-Cruz, J M; Chieffi, P P; Gryschek, R C B; Paula, F M

    2016-07-01

    Strongyloides venezuelensis is an intestinal nematode of rats, frequently used as a model for studying human and animal strongyloidiasis. In the present study, we evaluated parasitological, serological and molecular methods for the diagnosis of experimental S. venezuelensis in rats, Rattus norvegicus. Blood and faecal samples were collected and analysed up to 60 days post infection (pi) with adult worm recovery occurring from 5 to 45 days pi. Using an enzyme-linked immunosorbent assay (ELISA), serum levels of IgG antibodies increased up to 28 days pi, thereafter decreasing by day 60 pi. Polymerase chain reaction (PCR) assays detected S. venezuelensis DNA in faecal samples of rats from 5 to 21 days pi. The present study therefore represents the first step towards improving the diagnosis of experimental strongyloidiasis.

  7. Experimental Infection of Rhodnius prolixus (Hemiptera, Triatominae with Mycobacterium leprae Indicates Potential for Leprosy Transmission.

    Directory of Open Access Journals (Sweden)

    Arthur da Silva Neumann

    Full Text Available Leprosy is a chronic dermato-neurological disease caused by infection with Mycobacterium leprae. In 2013 almost 200,000 new cases of leprosy were detected around the world. Since the first symptoms take from years to decades to appear, the total number of asymptomatic patients is impossible to predict. Although leprosy is one of the oldest records of human disease, the mechanisms involved with its transmission and epidemiology are still not completely understood. In the present work, we experimentally investigated the hypothesis that the mosquitoes Aedes aegypti and Culex quinquefasciatus and the hemiptera Rhodnius prolixus act as leprosy vectors. By means of real-time PCR quantification of M. leprae 16SrRNA, we found that M. leprae remained viable inside the digestive tract of Rhodnius prolixus for 20 days after oral infection. In contrast, in the gut of both mosquito species tested, we were not able to detect M. leprae RNA after a similar period of time. Inside the kissing bug Rhodnius prolixus digestive tract, M. leprae was initially restricted to the anterior midgut, but gradually moved towards the hindgut, in a time course reminiscent of the life cycle of Trypanosoma cruzi, a well-known pathogen transmitted by this insect. The maintenance of M. leprae infectivity inside the digestive tract of this kissing bug is further supported by successful mice footpad inoculation with feces collected 20 days after infection. We conclude that Rhodnius prolixus defecate infective M. leprae, justifying the evaluation of the presence of M. leprae among sylvatic and domestic kissing bugs in countries endemic for leprosy.

  8. Experimental Infection of Rhodnius prolixus (Hemiptera, Triatominae) with Mycobacterium leprae Indicates Potential for Leprosy Transmission.

    Science.gov (United States)

    Neumann, Arthur da Silva; Dias, Felipe de Almeida; Ferreira, Jéssica da Silva; Fontes, Amanda Nogueira Brum; Rosa, Patricia Sammarco; Macedo, Rafael Enrique; Oliveira, José Henrique; Teixeira, Raquel Lima de Figueiredo; Pessolani, Maria Cristina Vidal; Moraes, Milton Ozório; Suffys, Philip Noel; Oliveira, Pedro L; Sorgine, Marcos Henrique Ferreira; Lara, Flavio Alves

    2016-01-01

    Leprosy is a chronic dermato-neurological disease caused by infection with Mycobacterium leprae. In 2013 almost 200,000 new cases of leprosy were detected around the world. Since the first symptoms take from years to decades to appear, the total number of asymptomatic patients is impossible to predict. Although leprosy is one of the oldest records of human disease, the mechanisms involved with its transmission and epidemiology are still not completely understood. In the present work, we experimentally investigated the hypothesis that the mosquitoes Aedes aegypti and Culex quinquefasciatus and the hemiptera Rhodnius prolixus act as leprosy vectors. By means of real-time PCR quantification of M. leprae 16SrRNA, we found that M. leprae remained viable inside the digestive tract of Rhodnius prolixus for 20 days after oral infection. In contrast, in the gut of both mosquito species tested, we were not able to detect M. leprae RNA after a similar period of time. Inside the kissing bug Rhodnius prolixus digestive tract, M. leprae was initially restricted to the anterior midgut, but gradually moved towards the hindgut, in a time course reminiscent of the life cycle of Trypanosoma cruzi, a well-known pathogen transmitted by this insect. The maintenance of M. leprae infectivity inside the digestive tract of this kissing bug is further supported by successful mice footpad inoculation with feces collected 20 days after infection. We conclude that Rhodnius prolixus defecate infective M. leprae, justifying the evaluation of the presence of M. leprae among sylvatic and domestic kissing bugs in countries endemic for leprosy.

  9. Experimental infection of Aphanomyces invadans and susceptibility in seven species of tropical fish

    Directory of Open Access Journals (Sweden)

    Seyedeh F. Afzali

    2015-09-01

    Full Text Available Aim: Epizootic ulcerative syndrome (EUS causes by aquatic oomycete fungus, Aphanomyces invadans is a dangerous fish disease of a wide range of fresh and brackish water, wild and farmed fish throughout the world. The objective of the present study was to determine the susceptibility of a number of tropical fish species to the EUS and compare the severity of infection between experimental groups. Materials and Methods: Snakehead, Channa striata (Bloch, 1793; snakeskin gourami, Trichopodus pectoralis (Regan, 1910; koi carp, Cyprinus carpio (Linnaeus, 1758; broadhead catfish, Clarias macrocephalus (Günther, 1864; goldfish, Carassius auratus (Linnaeus, 1758; climbing perch, Anabas testudineus (Bloch, 1792; and Nile tilapia, Oreochromis niloticus (Linnaeus, 1758 were challenged by intramuscular injection using zoospores of Aphanomyces invadans (NJM9701. The infected fish skins and muscles were examined for EUS histopathological characteristics, and the results on the severity of lesions and mortality were analyzed using SPSS program. Results: All zoospore-injected fish were shown to be susceptible to the EUS infection except Nile tilapia. Although, the general histopathological pattern was similar in the zoospore-injected group, but there were some variation in granulomatous reaction, that is the presence or absence of giant cells, and time of mortality were detected. The result of statistical analysis showed that there was a significant difference between species, (c2=145.11 and p<0.01. Conclusion: Gourami, koi carp, and catfish were demonstrated to be highly susceptible while goldfish and climbing perch were found to be moderately susceptible to the EUS infection. These findings suggested that the cellular response of fish to mycotic infection and granulomatous reaction varied in different fish species, which could not be an indicator of susceptibility or resistant to the EUS itself, although it was shown that the granulation rate and the level of

  10. Foot-and-Mouth Disease in Red Deer - Experimental Infection and Test Methods Performance.

    Science.gov (United States)

    Kittelberger, R; Nfon, C; Swekla, K; Zhang, Z; Hole, K; Bittner, H; Salo, T; Goolia, M; Embury-Hyatt, C; Bueno, R; Hannah, M; Swainsbury, R; O'Sullivan, C; Spence, R; Clough, R; McFadden, A; Rawdon, T; Alexandersen, S

    2017-02-01

    The aim of this study was to evaluate a number of foot-and-mouth disease (FMD) test methods for use in red deer. Ten animals were intranasally inoculated with the FMD virus (FMDV) O UKG 11/2001, monitored for clinical signs, and samples taken regularly (blood, serum, oral swabs, nasal swabs, probang samples and lesion swabs, if present) over a 4-week period. Only one animal, deer 1103, developed clinical signs (lesions under the tongue and at the coronary band of the right hind hoof). It tested positive by 3D and IRES real-time reverse transcription polymerase chain reaction (rRT-PCR) in various swabs, lesion materials and serum. In a non-structural protein (NSP) in-house ELISA (NSP-ELISA-IH), one commercial ELISA (NSP-ELISA-PR) and a commercial antibody NSP pen side test, only deer 1103 showed positive results from day post-inoculation (dpi) 14 onwards. Two other NSP-ELISAs detected anti-NSP serum antibodies with lower sensitivity. It also showed rising antibody levels in the virus neutralization test (VNT), the in-house SPO-ELISA-IH and the commercial SPO-ELISA-PR at dpi 9, and in another two commercial SPO-ELISAs at dpi 12 (SPO-ELISA-IV) and dpi 19 (SPO-ELISA-IZ), respectively. Six of the red deer that had been rRT-PCR and antibody negative were re-inoculated intramuscularly with the same O-serotype FMDV at dpi 14. None of these animals became rRT-PCR or NSP-ELISA positive, but all six animals became positive in the VNT, the in-house SPO-ELISA-IH and the commercial SPO-ELISA-PR. Two other commercial SPO-ELISAs were less sensitive or failed to detect animals as positive. The rRT-PCRs and the four most sensitive commercial ELISAs that had been used for the experimentally inoculated deer were further evaluated for diagnostic specificity (DSP) using 950 serum samples and 200 nasal swabs from non-infected animals. DSPs were 100% for the rRT-PCRs and between 99.8 and 100% for the ELISAs. © 2015 The Authors. Transboundary and Emerging Diseases Published by Blackwell

  11. Investigation of four {sup 99m}Tc-labeled bacteriophages for infection-specific imaging

    Energy Technology Data Exchange (ETDEWEB)

    Rusckowski, Mary [Division of Nuclear Medicine, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655-0243 (United States)], E-mail: mary.rusckowski@umassmed.edu; Gupta, Suresh; Liu Guozheng; Dou Shuping; Hnatowich, Donald J. [Division of Nuclear Medicine, Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655-0243 (United States)

    2008-05-15

    Introduction: This study investigated radiolabeled bacteriophages for specific detection of infection through gamma imaging. Previously, a {sup 99m}Tc-labeled M13 phage demonstrated specific binding for its host Escherichia coli in vitro and in mice through imaging. Methods: This study was extended to phages P22, E79, VD-13 and phage 60. Each was radiolabeled with {sup 99m}Tc using the chelator MAG{sub 3}, and were evaluated for binding to host and non-host bacteria in vitro and in a mouse infection model. Results: In vitro, each {sup 99m}Tc-phage bound to its host at least 4-fold higher than to non-host bacteria. For example, {sup 99m}Tc-E79 showed 10- to 20-fold greater binding to host Pseudomonas aeruginosa compared to non-host Escherichia coli and Salmonella enterica, and {sup 99m}Tc-phage 60 showed 20-fold greater binding to host Klebsiella pneumoniae over non-hosts. Mice received host or non-host bacteria in one thigh, and 3 h later, the {sup 99m}Tc-phages were administered intravenously. After a further 3 h, the tissues were counted. Liver accumulation was highest for {sup 99m}Tc-E79, averaging 39% compared to an average of 13% for the other {sup 99m}Tc-phages. Animals infected with host bacteria showed infected thigh/normal thigh ratios of 14.2 for {sup 99m}Tc-E79, 2.9 for {sup 99m}Tc-P22, 3.5 for {sup 99m}Tc-VD-13 and 2.1 for {sup 99m}Tc-phage 60. Conclusions: Although specific host binding was observed in vitro for each of these four {sup 99m}Tc-phages, only {sup 99m}Tc-E79 showed specificity for its host in an in vivo model.

  12. Experimental evaluation and design of unfilled and concrete-filled FRP composite piles : Task 4A : design specifications.

    Science.gov (United States)

    2015-08-01

    The overall goal of this project is the experimental evaluation and design of unfilled and concrete-filled FRP composite piles for load-bearing in bridges. This report covers Task 4A, Design Specifications. : Structural design specifications are base...

  13. Indirect diagnostic tests for the detection of subclinical mastitis in dairy goats experimentally infected with Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Rodolfo de Moraes Peixoto

    2016-07-01

    Full Text Available ABSTRACT: The aim of the present study was to assess two diagnostic techniques (California mastitis test (CMT and the somatic cell count (SCC that can diagnose mastitis in dairy goats. Experimental infection was conducted using 20 mammary glands, a strain of Staphylococcus aureus, an infectious dose of 1.2x108CFU mL-1 and a volume of 1mL per mammary gland. The CMT and the SCC were used to detect subclinical mastitis. Bacterial culture (BC was performed immediately after milk collection and was used as the gold standard. Four experimental time points were established (0, 24, 48 and 72 hours post-inoculation. Analysis of the ROC curve confirmed that the best combination of sensitivity and specificity were obtained with a cutoff point of 405.5, 6030.0 and 729.5x103 cells mL-1, respectively at M1, M2 and M3. Furthermore, considering the drop in sensitivity throughout the experimental time points, the use of serial bacterial cultures are recommended, particularly in herds with a high prevalence of S. aureus.

  14. Experimental infection of hamsters with avian paramyxovirus serotypes 1 to 9

    Directory of Open Access Journals (Sweden)

    Samuel Arthur S

    2011-02-01

    Full Text Available Abstract Avian paramyxoviruses (APMVs are frequently isolated from domestic and wild birds throughout the world and are separated into nine serotypes (APMV-1 to -9. Only in the case of APMV-1, the infection of non-avian species has been investigated. The APMVs presently are being considered as human vaccine vectors. In this study, we evaluated the replication and pathogenicity of all nine APMV serotypes in hamsters. The hamsters were inoculated intranasally with each virus and monitored for clinical disease, pathology, histopathology, virus replication, and seroconversion. On the basis of one or more of these criteria, each of the APMV serotypes was found to replicate in hamsters. The APMVs produced mild or inapparent clinical signs in hamsters except for APMV-9, which produced moderate disease. Gross lesions were observed over the pulmonary surface of hamsters infected with APMV-2 & -3, which showed petechial and ecchymotic hemorrhages, respectively. Replication of all of the APMVs except APMV-5 was confirmed in the nasal turbinates and lungs, indicating a tropism for the respiratory tract. Histologically, the infection resulted in lung lesions consistent with bronchointerstitial pneumonia of varying severity and nasal turbinates with blunting or loss of cilia of the epithelium lining the nasal septa. The majority of APMV-infected hamsters exhibited transient histological lesions that self resolved by 14 days post infection (dpi. All of the hamsters infected with the APMVs produced serotype-specific HI or neutralizing antibodies, confirming virus replication. Taken together, these results demonstrate that all nine known APMV serotypes are capable of replicating in hamsters with minimal disease and pathology.

  15. Reduced Treponema pallidum–Specific Opsonic Antibody Activity in HIV-Infected Patients With Syphilis

    Science.gov (United States)

    Marra, Christina M.; Tantalo, Lauren C.; Sahi, Sharon K.; Dunaway, Shelia B.; Lukehart, Sheila A.

    2016-01-01

    Background. Human immunodeficiency virus (HIV)–infected individuals may have poorer serological responses to syphilis treatment and may be more likely to experience neurosyphilis. Treponema pallidum is cleared from sites of infection by opsonization, ingestion, and killing by macrophages. Methods. Serum samples from 235 individuals with syphilis were tested for T. pallidum–specific opsonic activity. Blood T. pallidum concentrations were determined by real-time polymerase chain reaction amplification of the tp0574 gene, and T. pallidum was detected in cerebrospinal fluid (CSF) by reverse-transcriptase polymerase chain reaction of 16S ribosomal RNA. Results. Opsonic activity was higher with higher serum rapid plasma reagin titers (P pallidum was detectable, those with the highest opsonic activity had lower blood T. pallidum concentrations. In multivariable analyses, there was not a significant relationship between opsonic activity and detection of T. pallidum in CSF or CSF-VDRL reactivity. Conclusions. Serum T. pallidum–specific opsonic activity is significantly lower in HIV-infected individuals. Impaired T. pallidum–specific immune responses could contribute to differences in the course of disease or treatment response. PMID:26655298

  16. Reduced Treponema pallidum-Specific Opsonic Antibody Activity in HIV-Infected Patients With Syphilis.

    Science.gov (United States)

    Marra, Christina M; Tantalo, Lauren C; Sahi, Sharon K; Dunaway, Shelia B; Lukehart, Sheila A

    2016-04-15

    Human immunodeficiency virus (HIV)-infected individuals may have poorer serological responses to syphilis treatment and may be more likely to experience neurosyphilis. Treponema pallidum is cleared from sites of infection by opsonization, ingestion, and killing by macrophages. Serum samples from 235 individuals with syphilis were tested for T. pallidum-specific opsonic activity. Blood T. pallidum concentrations were determined by real-time polymerase chain reaction amplification of the tp0574 gene, and T. pallidum was detected in cerebrospinal fluid (CSF) by reverse-transcriptase polymerase chain reaction of 16S ribosomal RNA. Opsonic activity was higher with higher serum rapid plasma reagin titers (P pallidum was detectable, those with the highest opsonic activity had lower blood T. pallidum concentrations. In multivariable analyses, there was not a significant relationship between opsonic activity and detection of T. pallidum in CSF or CSF-VDRL reactivity. Serum T. pallidum-specific opsonic activity is significantly lower in HIV-infected individuals. Impaired T. pallidum-specific immune responses could contribute to differences in the course of disease or treatment response. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  17. Experimental infection and transmission of Leishmania by Lutzomyia cruzi (Diptera: Psychodidae: Aspects of the ecology of parasite-vector interactions.

    Directory of Open Access Journals (Sweden)

    Everton Falcão de Oliveira

    2017-02-01

    Full Text Available Several parameters should be addressed before incriminating a vector for Leishmania transmission. Those may include its ability to become infected by the same Leishmania species found in humans, the degree of attractiveness for reservoirs and humans and capacity to sustain parasite infection under laboratory conditions. This study evaluated the vectorial capacity of Lutzomyia cruzi for Leishmania infantum and gathered information on its ability to harbor L. amazonensis. Laboratory-reared Lu. cruzi were infected experimentally by feeding them on dogs infected naturally with L. infantum and hamsters infected with L. amazonensis. Sand fly attractiveness to dogs and humans was determined using wild caught insects. The expected daily survival of infected Lu. cruzi, the duration of the gonotrophic cycle, and the extrinsic incubation period were also investigated for both parasites. Vector competence was investigated for both Leishmania species. The mean proportion of female sand flies that fed on hosts was 0.40. For L. infantum and L. amazonensis, Lu. cruzi had experimental infection rates of 10.55% and 41.56%, respectively. The extrinsic incubation period was 3 days for both Leishmania species, regardless of the host. Survival expectancy of females infected with L. infantum and L. amazonensis after completing the gonotrophic cycle was 1.32 and 0.43, respectively. There was no association between L. infantum infection and sand fly longevity, but L. amazonensis-infected flies had significantly greater survival probabilities. Furthermore, egg-laying was significantly detrimental to survival. Lu. cruzi was found to be highly attracted to both dogs and humans. After a bloodmeal on experimentally infected hosts, both parasites were able to survive and develop late-stage infections in Lu. cruzi. However, transmission was demonstrated only for L. amazonensis-infected sand flies. In conclusion, Lu. cruzi fulfilled several of the requirements of vectorial

  18. HIV-1 Infection Is Associated with Depletion and Functional Impairment ofMycobacterium tuberculosis-Specific CD4 T Cells in Individuals with Latent Tuberculosis Infection.

    Science.gov (United States)

    Day, Cheryl L; Abrahams, Deborah A; Harris, Levelle D; van Rooyen, Michele; Stone, Lynnett; de Kock, Marwou; Hanekom, Willem A

    2017-09-15

    Coinfection with HIV is the single greatest risk factor for reactivation of latent Mycobacterium tuberculosis infection (LTBI) and progression to active tuberculosis disease. HIV-associated dysregulation of adaptive immunity by depletion of CD4 Th cells most likely contributes to loss of immune control of LTBI in HIV-infected individuals, although the precise mechanisms whereby HIV infection impedes successful T cell-mediated control of M. tuberculosis have not been well defined. To further delineate mechanisms whereby HIV impairs protective immunity to M. tuberculosis , we evaluated the frequency, phenotype, and functional capacity of M. tuberculosis -specific CD4 T cells in HIV-infected and HIV-uninfected adults with LTBI. HIV infection was associated with a lower total frequency of cytokine-producing M. tuberculosis -specific CD4 T cells, and preferential depletion of a discrete subset of M. tuberculosis -specific IFN-γ + IL-2 - TNF-α + CD4 T cells. M. tuberculosis -specific CD4 T cells in HIV-infected individuals expressed significantly higher levels of Ki67, compared with HIV-uninfected individuals, thus indicating recent activation and turnover of these cells in vivo. The ex vivo proliferative capacity of M. tuberculosis -specific CD4 T cells was markedly impaired in HIV-infected individuals, compared with HIV-uninfected individuals. Moreover, HIV infection was associated with increased M. tuberculosis Ag-induced CD4 T cell death ex vivo, indicating a possible mechanism contributing to impaired proliferative capacity of M. tuberculosis -specific CD4 T cells in HIV-infected individuals. These data provide new insights into the parameters of M. tuberculosis -specific CD4 T cell immunity that are impaired in HIV-infected individuals with LTBI, which may contribute to their increased risk of developing active tuberculosis disease. Copyright © 2017 by The American Association of Immunologists, Inc.

  19. The nutritional status affects the complete blood count of goats experimentally infected with Haemonchus contortus.

    Science.gov (United States)

    Cériac, S; Jayles, C; Arquet, R; Feuillet, D; Félicité, Y; Archimède, H; Bambou, J-C

    2017-11-09

    Gastrointestinal nematode (GIN) remains the most important pathogenic constraint of small ruminant production worldwide. The improvement of the host immune response against GIN though breeding for improved animal resistance, vaccination and nutritional supplementation appear as very promising methods. The objective of this study was to investigate the effect of four nutritional status differing in protein and energy levels (Hay: 5.1 MJ/Kg of dry matter (DM) and 7.6% of crude protein (CP), Ban: 8.3 MJ/Kg of DM and 7.5% of CP, Soy: 7.6 MJ/Kg of DM and 17.3% of CP, BS: 12.7 MJ/Kg of DM and 7.4% of CP) on the haematological disturbances due to Haemonchus contortus infection in Creole kid goats. No significant effect of the nutritional status was observed for faecal egg count (FEC) but the experimental infection induced haematological disturbances whose intensity and lengthening were dependent on the nutritional status. A transient marked regenerative macrocytic hypochromic anaemia as revealed by a decrease of packed cell volume (PCV), red blood cells (RBC) and hemoglobin and an increase of reticulocytes was observed in all infected groups except Hay. In this latter, the anaemia settled until the end of the experiment. Furthermore, H. contortus induced a thrombocytopenia significantly more pronounced in the group under the lowest nutritional status in term of protein (Hay and Ban). A principal component analysis revealed that the variables that discriminated the nutritional status were the average daily gain (ADG) and the PCV, considered as measures of the level of resilience to H. contortus infection. Moreover, the variables that discriminated infected and non-infected animals were mostly related to the biology of RBC (i.e. size and hemoglobin content) and they were correlated with FEC. The severity and the lengthening of the regenerative anaemia and the thrombocytopenia induced by H. contortus have been affected by the nutritional status. The protein enriched

  20. Evaluation of animal performance, feed intake, and economic losses in sheep experimentally infected with Trypanosoma vivax

    Directory of Open Access Journals (Sweden)

    Parmênedes Dias de Brito

    2017-06-01

    Full Text Available Trypanosoma vivax is a protozoan originating from the African continent, which, although it has not yet been able to complete its biological cycle in South America, due to the absence of the tsetse fly, can still cause death in ruminants. The objective of this study was to verify the effects of T. vivax on the measurements and indices in sheep that characterize animal performance, as well as on economic losses in meat animals. Twenty intact adult male sheep were used for this study, all of approximately the same ages and weights, reared in confinement, and subjected to the same management and diet, which was balanced and supplemented with adequate minerals. The animals were divided into two groups: the control group (CG and the infected group (IG, which was inoculated intravenously with 1.3 x 105 trypomastigotes of T. vivax. Feed intake was verified daily, whereas the feed conversion (FC, feed efficiency index (FEI, and weight gain were obtained weekly. Total weight gain (TWG was determined after 70 days post-infection. The economic loss was calculated by subtracting the value obtained (IG from the expected value (CG, and the difference was expressed as a percentage. A randomized block design was used to isolate the effect of the initial weight. The means were compared by the Student “t” test at 5%. Of the 10 infected animals, one died from the parasitism, yielding a rate much lower than that observed in natural outbreaks. The groups presented similar feed intakes throughout the experimental period; however, the TWG of the infected group was significantly lower (50.7% than that of the CG. Similarly, the daily weight gain (DWG, feed conversion (FC, and feed efficiency index (FEI of the IG were significantly lower than those of the CG. In addition, the worst rates of FC and FEI coincided with parasitemia peaks and recurrences, probably due to immunological demand and tissue repair. The abdominal circumference of the infected animals was

  1. Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection

    DEFF Research Database (Denmark)

    Brock, I; Weldingh, K; Leyten, EM

    2004-01-01

    BCG-vaccinated controls. The combination of the most promising stretches from this analysis showed a sensitivity level (57%) comparable to the level found with the two well-known M. tuberculosis-specific proteins ESAT-6 and CFP-10 (75 and 66%, respectively). The combination of ESAT-6, CFP-10...... method for immunological detection of tuberculosis infection, the tuberculin skin test, has low specificity. Antigens specific for Mycobacterium tuberculosis to replace purified protein derivative are therefore urgently needed. We have performed a rigorous assessment of the diagnostic potential of four...... selected and combined the specific peptide stretches from the four proteins not recognized by M. bovis BCG-vaccinated individuals. These peptide stretches were tested with peripheral blood mononuclear cells obtained from patients with microscopy- or culture-confirmed tuberculosis and from healthy M. bovis...

  2. Specific dysregulation of IFNγ production by natural killer cells confers susceptibility to viral infection.

    Directory of Open Access Journals (Sweden)

    Nassima Fodil

    2014-12-01

    Full Text Available Natural Killer (NK cells contribute to the control of viral infection by directly killing target cells and mediating cytokine release. In C57BL/6 mice, the Ly49H activating NK cell receptor plays a key role in early resistance to mouse cytomegalovirus (MCMV infection through specific recognition of the MCMV-encoded MHC class I-like molecule m157 expressed on infected cells. Here we show that transgenic expression of Ly49H failed to provide protection against MCMV infection in the naturally susceptible A/J mouse strain. Characterization of Ly49H(+ NK cells from Ly49h-A transgenic animals showed that they were able to mount a robust cytotoxic response and proliferate to high numbers during the course of infection. However, compared to NK cells from C57BL/6 mice, we observed an intrinsic defect in their ability to produce IFNγ when challenged by either m157-expressing target cells, exogenous cytokines or chemical stimulants. This effect was limited to NK cells as T cells from C57BL/6 and Ly49h-A mice produced comparable cytokine levels. Using a panel of recombinant congenic strains derived from A/J and C57BL/6 progenitors, we mapped the genetic basis of defective IFNγ production to a single 6.6 Mb genetic interval overlapping the Ifng gene on chromosome 10. Inspection of the genetic interval failed to reveal molecular differences between A/J and several mouse strains showing normal IFNγ production. The chromosome 10 locus is independent of MAPK signalling or decreased mRNA stability and linked to MCMV susceptibility. This study highlights the existence of a previously uncovered NK cell-specific cis-regulatory mechanism of Ifnγ transcript expression potentially relevant to NK cell function in health and disease.

  3. Experimental Infection of Swine by Isospora suis Biester 1934 for Species Confirmation

    Directory of Open Access Journals (Sweden)

    Silvia Maria Oliveira Sayd

    1998-11-01

    Full Text Available A survey of Isospora suis performed in 177 faecal samples from 30 swine farms detected thin wall type I. suis oocysts in seven samples. This type of oocyst measuring 23.9 by 20.7 mm had a retracted thin wall similar to that of the genus Sarcocystis. This type of oocysts, isolated from four different faecal samples, was inoculated in four-five-days-old piglets free of contamination in order to verify the life cycle and pathogenicity of the species. The pigs were kept in individual metal cages and fed with cow milk. Daily faecal collections and examinations were performed until the 21st day after infection. MacMaster and Sheather' s methods were used for oocyst counting and identification. Infected piglets produced yellowish-pasty diarrhoea with slight dehydration. The prepatent and patent periods were respectively from 6 to 9 and 3 to 10 days after infection. Oocyst elimination was interrupted on the 10th and 11th days after infection with biphasic cycles. Thin and thick wall oocysts were detected in the same faecal samples. Thin walls were not observed in unsporulated oocysts. The observations suggest that this type of oocysts could appear in specific strains which occur in the later stages of their development. These oocysts seem to be responsible for clinical and pathogenic signs of neonatal isosporosis in pigs.

  4. Toxoplasma gondii infection specifically increases the levels of key host microRNAs.

    Directory of Open Access Journals (Sweden)

    Gusti M Zeiner

    2010-01-01

    Full Text Available The apicomplexan parasite Toxoplasma gondii can infect and replicate in virtually any nucleated cell in many species of warm-blooded animals; thus, it has evolved the ability to exploit well-conserved biological processes common to its diverse hosts. Here we have investigated whether Toxoplasma modulates the levels of host microRNAs (miRNAs during infection.Using microarray profiling and a combination of conventional molecular approaches we report that Toxoplasma specifically modulates the expression of important host microRNAs during infection. We show that both the primary transcripts for miR-17 approximately 92 and miR-106b approximately 25 and the pivotal miRNAs that are derived from miR-17 approximately 92 display increased abundance in Toxoplasma-infected primary human cells; a Toxoplasma-dependent up-regulation of the miR-17 approximately 92 promoter is at least partly responsible for this increase. The abundance of mature miR-17 family members, which are derived from these two miRNA clusters, remains unchanged in host cells infected with the closely related apicomplexan Neospora caninum; thus, the Toxoplasma-induced increase in their abundance is a highly directed process rather than a general host response to infection.Altered levels of miR-17 approximately 92 and miR-106b approximately 25 are known to play crucial roles in mammalian cell regulation and have been implicated in numerous hyperproliferative diseases although the mechanisms driving their altered expression are unknown. Hence, in addition to the implications of these findings on the host-pathogen interaction, Toxoplasma may represent a powerful probe for understanding the normal mechanisms that regulate the levels of key host miRNAs.

  5. Comparison between experimental and predicted specific absorption rate of functionalized iron oxide nanoparticle suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Yuan [Mechanical, Aerospace and Nuclear Engineering Department Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Tasciuc, Diana-Andra Borca, E-mail: borcad@rpi.edu [Mechanical, Aerospace and Nuclear Engineering Department Rensselaer Polytechnic Institute, Troy, NY 12180 (United States)

    2011-10-15

    Radio-frequency heated magnetic nanoaparticle suspensions have potential applications in cancer hyperthermia. To optimize these systems for hyperthermia applications it is important to be able to predict how their heat generation or specific absorption rate (SAR) is influenced by various factors, including nanoparticle coating or functionalization and aggregation. However, at present it is unclear how well-existing models predict experimental SAR results. Direct comparisons between predicted and measured SAR are scarce, despite an abundance of works reporting on heat generation rate of various magnetic nanoparticles suspensions. The main objective of this paper is to experimentally assess the validity of current models for SAR and extract information on the effects of coating and aggregation on heat generation rate. In this context, AC susceptibility and magnetization of suspensions of uncoated particles, as well as particles with aminosilane and carboxymethyl-dextran functionalizations, were measured. These properties were then used to predict the heat generation rate in alternating magnetic field starting from first principles, which was then compared to measured SAR. It was found that experimental SAR agrees relatively well with predictions (by a factor of two) when using experimental susceptibility values for the SAR calculation. However, for uncoated and amine-functionalized particles poor agreement (more than an order of magnitude difference) was found when the experimental susceptibility was substituted with predictions based on the Debye model. This apparent discrepancy is attributed to dipolar interactions between nanoparticles within aggregates in these samples, which enhances the imaginary part of the susceptibility and, consequently, the SAR values. The results also suggest that the thermal resistance effect of the coating has little influence on the SAR. - Highlights: > Thermal resistance of nanoparticle coating has little impact on heat dissipation

  6. Pelacakan Secara Imunohistokimiawi Antigen Virus pada Ayam yang Diinfeksi dengan Virus Penyakit Tetelo (IMMUNOHISTOCHEMICAL DETECTION OF VIRAL ANTIGEN IN TISSUE OF CHICKENS EXPERIMENTALLY INFECTED WITH NEWCASTLE DISEASE VIRUS

    Directory of Open Access Journals (Sweden)

    Anak Agung Ayu Mirah Adi

    2013-07-01

    Full Text Available In order to study the distribution of Newcastle disease virus (NDV following infection, chickenswere experimentally infected with visceretropic velogenic NDV isolate. Monoclonal antibodies (mAbsagainst the NDV LaSota vaccine strain were then produced to detect viral antigen in the infectedorgans. The mAbs were firstly tested for their specificity by enzyme linked immunosorbent assay(ELISA using NDV and normal allantoic fluids as antigens. Eight mAbs specific against NDVwere isolated and two mAbs were used for immunodetection of NDV antigen in chicken’s tissues.By immunohistochemistry labeled streptavidin-biotin (LSAB staining NDV–antigen was detectedin paraffin embedded tissues of NDV-infected chickens. NDV antigen was not detected in noninfected chickens. In the infected chickens, high intensity of NDV antigen was detected in thelymphoid tissues, lung and intestine. The NDV antigen with a lesser intensity was detected in thebrain, trachea, liver and myocardium. This study shows that although viscerotropic velogenicNDV isolate can infect almost all organs, the main target of infection are lung, intestine andlymphoids tissues

  7. Peste des Petits Ruminants Virus Tissue Tropism and Pathogenesis in Sheep and Goats following Experimental Infection

    Science.gov (United States)

    Truong, Thang; Boshra, Hani; Embury-Hyatt, Carissa; Nfon, Charles; Gerdts, Volker; Tikoo, Suresh; Babiuk, Lorne A.; Kara, Pravesh; Chetty, Thireshni; Mather, Arshad; Wallace, David B.; Babiuk, Shawn

    2014-01-01

    Peste des petits ruminants (PPR) is a viral disease which primarily affects small ruminants, causing significant economic losses for the livestock industry in developing countries. It is endemic in Saharan and sub-Saharan Africa, the Middle East and the Indian sub-continent. The primary hosts for peste des petits ruminants virus (PPRV) are goats and sheep; however recent models studying the pathology, disease progression and viremia of PPRV have focused primarily on goat models. This study evaluates the tissue tropism and pathogenesis of PPR following experimental infection of sheep and goats using a quantitative time-course study. Upon infection with a virulent strain of PPRV, both sheep and goats developed clinical signs and lesions typical of PPR, although sheep displayed milder clinical disease compared to goats. Tissue tropism of PPRV was evaluated by real-time RT-PCR and immunohistochemistry. Lymph nodes, lymphoid tissue and digestive tract organs were the predominant sites of virus replication. The results presented in this study provide models for the comparative evaluation of PPRV pathogenesis and tissue tropism in both sheep and goats. These models are suitable for the establishment of experimental parameters necessary for the evaluation of vaccines, as well as further studies into PPRV-host interactions. PMID:24498032

  8. Technetium-99m stannous pyrophosphate imaging of experimental infective endocarditis. [Rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Riba, A.L.; Downs, J.; Thakur, M.L.; Gottschalk, A.; Andriole, V.T.; Zaret, B.L.

    1978-07-01

    Technetium-99m stannous pyrophosphate (/sup 99m/Tc-PYP) cardiac scintigraphy was performed in 15 rabbits with experimental Streptococcus sanguis aortic-valve infective endocarditis. The animals were imaged five to seven days after the administration of bacteria, and in each case abnormal accumulation of the tracer was visualized in the region of the aortic valve. Three types of cardiac scintigraphic patterns were demonstrated: focal, multifocal, and extensive, each correlating well with the anatomical extent of the lesion as defined by gross pathology. Tissue distribution studies demonstrated a 30 +- 5.3 (mean +- SEM) fold excess of radionuclide uptake in the infective endocarditis lesion compared with that of normal myocardium. Imaging of excised hearts from four animals showed an excellent correlation with in vivo imaging as well as gross pathology. Five animals with nonbacterial thrombotic aortic valve endocarditis demonstrated similar scintigraphic and tissue distribution results. In contrast, four normal animals failed to demonstrate abnormal /sup 99m/Tc-PYP cardiac scintigrams or tissue uptake. This study demonstrates that /sup 99m/Tc-PYP cardiac scintigraphy is a sensitive technique to detect experimental aortic valve endocarditis.

  9. Proteomic analysis of Ascaridia galli. Identification of immunoreactive proteins in naturally and experimentally infected hens.

    Science.gov (United States)

    González-Miguel, Javier; Marcos-Atxutegi, Cristina; de Castello, Roberta Bottari; Carpani, Sara; Morchón, Rodrigo; Simón, Fernando

    2013-09-23

    Ascaridia galli, intestinal parasite of domestic fowl, is responsible of economic losses in avian exploitations. However, molecular mechanisms that govern avian ascaridiasis remain largely unknown. The aim of the present work was to identify proteins of A. galli recognized by the immune system of naturally and experimentally infected hens, using two-dimensional electrophoresis (2-DE) and mass spectrometry (MS). Sixteen immunoreactive proteins of A. galli were identified. These proteins are mainly related to different metabolic processes, cell motility and binding activities. The timing evolution of this recognition pattern was studied using serum samples from experimentally infected hens, allowing us to observe an early recognition of many of these antigens. Many of them were isoforms from lipid and plasminogen-binding proteins. Moreover, plasminogen-binding activity has been related in other parasites with the facilitation of intra-organic migration, which represents an important fact in avian ascaridiasis. This work represents the first proteomic study of A. galli and could contribute to explain some aspects of parasite/host relationships of avian ascaridiasis. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Toxoplasma Co-infection Prevents Th2 Differentiation and Leads to a Helminth-Specific Th1 Response

    Directory of Open Access Journals (Sweden)

    Norus Ahmed

    2017-07-01

    Full Text Available Nematode infections, in particular gastrointestinal nematodes, are widespread and co-infections with other parasites and pathogens are frequently encountered in humans and animals. To decipher the immunological effects of a widespread protozoan infection on the anti-helminth immune response we studied a co-infection with the enteric nematode Heligmosomoides polygyrus in mice previously infected with Toxoplasma gondii. Protective immune responses against nematodes are dependent on parasite-specific Th2 responses associated with IL-4, IL-5, IL-13, IgE, and IgG1 antibodies. In contrast, Toxoplasma gondii infection elicits a strong and protective Th1 immune response characterized by IFN-γ, IL-12, and IgG2a antibodies. Co-infected animals displayed significantly higher worm fecundity although worm burden remained unchanged. In line with this, the Th2 response to H. polygyrus in co-infected animals showed a profound reduction of IL-4, IL-5, IL-13, and GATA-3 expressing T cells. Co-infection also resulted in the lack of eosinophilia and reduced expression of the Th2 effector molecule RELM-β in intestinal tissue. In contrast, the Th1 response to the protozoan parasite was not diminished and parasitemia of T. gondii was unaffected by concurrent helminth infection. Importantly, H. polygyrus specific restimulation of splenocytes revealed H. polygyrus-reactive CD4+ T cells that produce a significant amount of IFN-γ in co-infected animals. This was not observed in animals infected with the nematode alone. Increased levels of H. polygyrus-specific IgG2a antibodies in co-infected mice mirrored this finding. This study suggests that polarization rather than priming of naive CD4+ T cells is disturbed in mice previously infected with T. gondii. In conclusion, a previous T. gondii infection limits a helminth-specific Th2 immune response while promoting a shift toward a Th1-type immune response.

  11. Key metalloproteinases are expressed by specific cell types in experimental autoimmune encephalomyelitis

    DEFF Research Database (Denmark)

    Toft-Hansen, Henrik; Nuttall, Robert K; Edwards, Dylan R

    2004-01-01

    animal model, experimental autoimmune encephalomyelitis (EAE). We used real-time RT-PCR to profile the expression of all 22 known mouse MMPs, seven ADAMs, and all four known TIMPs in spinal cord from SJL/J mice and mice with adoptively transferred myelin basic protein (MBP)-specific EAE. A significant...... and >3-fold alteration in expression was observed for MMP-8, MMP-10, MMP-12, ADAM-12, and TIMP-1, which were up-regulated, and for MMP-15, which was down-regulated. Expression levels correlated with disease course, with all but ADAM-12 returning toward control levels in remission. To examine potential...

  12. Dynamics of Pathological and Virological Findings During Experimental Calpox Virus Infection of Common Marmosets (Callithrix jacchus

    Directory of Open Access Journals (Sweden)

    Anne Schmitt

    2017-11-01

    Full Text Available Experimental intranasal infection of marmosets (Callithrix jacchus with calpox virus results in fatal disease. Route and dose used for viral inoculation of the test animals mimics the natural transmission of smallpox, thus representing a suitable model to study pathogenesis and to evaluate new vaccines against orthopoxvirus infection. However, the pathogenic mechanisms leading to death are still unclear. Therefore, our study aimed at investigating the kinetics of pathological alterations to clarify the pathogenesis in calpox virus infection. Following intranasal inoculation with two different viral doses, common marmosets were sacrificed on days 3, 5, 7, 10 and 12 post inoculation. Collected tissue was screened using histopathology, immunohistochemistry, transmission electron microscopy, and virological assays. Our data suggest that primary replication took place in nasal and bronchial epithelia followed by secondary replication in submandibular lymph nodes and spleen. Parallel to viremia at day 7, virus was detectable in many organs, mainly located in epithelial cells and macrophages, as well as in endothelial cells. Based on the onset of clinical signs, the histological and ultrastructural lesions and the immunohistochemical distribution pattern of the virus, the incubation period was defined to last 11 days, which resembles human smallpox. In conclusion, the data indicate that the calpox model is highly suitable for studying orthopoxvirus-induced disease.

  13. Experimental intraocular infection of exotic cockerels with field strain of velogenic Newcastle disease virus in Nigeria

    Directory of Open Access Journals (Sweden)

    Samaila Jonathan Badau

    2015-12-01

    Full Text Available Experimental intraocular (conjunctival infection of exotic cockerels with a new field strain of viscerotropic velogenic Newcastle Disease Virus (NDV was conducted to explore the concurrence of some pathological changes with humoral immune responses. After the NDV infection of 4-week-old cockerels, pathologic changes and antibody responses were observed. The clinical signs observed after the artificial inoculation included inappetence, depression, diarrhea, dyspnea, wing and leg paralysis, torticollis and weight loss. Morbidity due to the NDV was 100%, but mortality was 80% by day 18-21 post-infection. Early hyperthermia followed by terminal hypothermia, decreased packed cell volume (PCV, and 231.4 folds peak-antibody response were observed. Necrotic and/or inflammatory lesions were present in the proventriculus, intestine, liver, spleen, kidney and brain. Neurologic and digestive tract perturbations occurred in 10% and 85% of cases, respectively. The disease consistently caused stunted growth, decreased PCV, and necro-inflammatroy lesions concurrent with antibody response, suggesting probable involvement of immune-mediated mechanisms and cell membrane desialylation by viral neuraminidase in the pathogenesis.

  14. Lack of viable parasites in cured 'Parma Ham' (PDO), following experimental Toxoplasma gondii infection of pigs.

    Science.gov (United States)

    Genchi, Marco; Vismarra, Alice; Mangia, Carlo; Faccini, Silvia; Vicari, Nadia; Rigamonti, Sara; Prati, Paola; Marino, Anna Maria; Kramer, Laura; Fabbi, Massimo

    2017-09-01

    Twelve Large White pigs were experimentally infected with 1000 Toxoplasma gondii oocysts/each. Serology was carried out at different time points post infection (p.i.) and animals were slaughtered at four months p.i. One of two thighs was examined for T. gondii infection status by PCR and bioassay in mice. The other thigh was processed for Parma ham production. Four thighs were examined after twelve months of curing, four after fourteen months and four were examined after sixteen months. Cured hams were analyzed by PCR, bioassay and in-vitro cultivation on Vero cells followed by real-time PCR. Pigs seroconverted from day 21 p.i. Bioassays were positive for all fresh thighs, but negative for cured hams. PCR was positive for parasite DNA from most thighs both at slaughter and post curing, but parasite growth was not observed following in vitro cultivation and real-time PCR. Results indicate that the curing process of Parma Ham (PDO), when carried out according to the Parma Ham consortium regulations, can inactivate T. gondii tissue cysts. Results would suggest that food-borne transmission of T. gondii to consumers from Parma ham can be excluded. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Efficacy of toltrazuril and ponazuril against experimental Neospora caninum infection in mice.

    Science.gov (United States)

    Gottstein, B; Eperon, S; Dai, W J; Cannas, A; Hemphill, A; Greif, G

    2001-01-01

    Neosporosis is a disease affecting predominantly fetal development in cattle and dog hosts; and it may cause neuromuscular disfunction in infected newborn calves and pups. Predispositions--including, e.g. transient immunosuppression during pregnancy--may result in an increased dissemination of the parasite within the host or its offspring. Chemotherapeutic treatment of neosporosis may be an issue, provided that an appropriate drug is made available. In this respect, we describe the use of a mouse model for the evaluation of toltrazuril and ponazuril medication as a means of preventing parasite dissemination and subsequent formation of cerebral lesions. Toltrazuril- and ponazuril-treated mice were experimentally infected intraperitoneally (i.p.) with 2 x 10(6) Neospora caninum tachyzoites. The infection was monitored at three levels: clinically, by assessing symptoms, histologically, by assessing the occurrence of cerebral lesions and parasites by immunohistochemistry, and on the molecular level, by detection of parasite DNA using PCR. Chemotherapy using either toltrazuril or ponazuril, both applied in a drinking-water formulation (20 mg toltrazuril or ponazuril kg(-1) body weight day(-1)) completely prevented the formation of cerebral lesions in all treated animals, as assessed by immunohistochemistry. PCR analyses of these treated animals showed that DNA-detectability was reduced by 91% and 90% upon toltrazuril and ponazuril medication, respectively.

  16. Genetic Vaccination against Experimental Infection with Myotropic Parasite Strains of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Adriano Fernando Araújo

    2014-01-01

    Full Text Available In earlier studies, we reported that a heterologous prime-boost regimen using recombinant plasmid DNA followed by replication-defective adenovirus vector, both containing Trypanosoma cruzi genes encoding trans-sialidase (TS and amastigote surface protein (ASP 2, provided protective immunity against experimental infection with a reticulotropic strain of this human protozoan parasite. Herein, we tested the outcome of genetic vaccination of F1 (CB10XBALB/c mice challenged with myotropic parasite strains (Brazil and Colombian. Initially, we determined that the coadministration during priming of a DNA plasmid containing the murine IL-12 gene improved the immune response and was essential for protective immunity elicited by the heterologous prime-boost regimen in susceptible male mice against acute lethal infections with these parasites. The prophylactic or therapeutic vaccination of resistant female mice led to a drastic reduction in the number of inflammatory infiltrates in cardiac and skeletal muscles during the chronic phase of infection with either strain. Analysis of the electrocardiographic parameters showed that prophylactic vaccination reduced the frequencies of sinus arrhythmia and atrioventricular block. Our results confirmed that prophylactic vaccination using the TS and ASP-2 genes benefits the host against acute and chronic pathologies caused by T. cruzi and should be further evaluated for the development of a veterinary or human vaccine against Chagas disease.

  17. Antischistosomal activity of hederacochiside C against Schistosoma japonicum harbored in experimentally infected animals.

    Science.gov (United States)

    Kang, Nai-Xin; Zhu, Yuan-Jian; Zhao, Jian-Ping; Zhu, Wei-Feng; Liu, Yan-Li; Xu, Qiong-Ming; Zhuge, Hong-Xiang; Khan, Ikhlas A; Yang, Shi-Lin

    2017-04-01

    The present study was undertaken to investigate whether hederacochiside C (HSC) possesses antischistosomal effects and anti-inflammatory response activities in Schistosoma japonicum-infected mice. Different concentrations of HSC were administrated to the mice infected by schistosomula or adult worm by intravenous injection twice a day for five consecutive days. The total worm burden, female worm burden, and the egg burden in liver of mice treated with 400 mg/kg HSC were fewer than those in non-treated ones. Murine immune responses following HSC treatment were investigated using enzyme-linked immunosorbent assays (ELISA). Our results indicated that 200 mg/kg HSC could reduce the expression of IgG, tumor necrosis factor (TNF)-α, interleukin (IL)-4 and IL-17 in comparison to infected group, exhibiting best immunomodulatory effects. In addition, scanning electron microscopical examination revealed that male worms treated with HSC lost their normal surface architecture since its surface showed extensive swelling, erosion, and peeling in tegumental regions. Remarkable amelioration was noticed in histopathological investigations, and 200 mg/kg HSC treatment could reduce the size of granulomatous inflammatory infiltrations in the liver which was reflected in nearly normalization of liver architecture. These results suggested that HSC had potential antischistosomal activity and provided a basis for subsequent experimental.

  18. Immunity to Lutzomyia whitmani Saliva Protects against Experimental Leishmania braziliensis Infection.

    Science.gov (United States)

    Gomes, Regis; Cavalcanti, Katrine; Teixeira, Clarissa; Carvalho, Augusto M; Mattos, Paulo S; Cristal, Juqueline R; Muniz, Aline C; Miranda, José Carlos; de Oliveira, Camila I; Barral, Aldina

    2016-11-01

    Previous works showed that immunization with saliva from Lutzomyia intermedia, a vector of Leishmania braziliensis, does not protect against experimental infection. However, L. braziliensis is also transmitted by Lutzomyia whitmani, a sand fly species closely related to Lu. intermedia. Herein we describe the immune response following immunization with Lu. whitmani saliva and the outcome of this response after L. braziliensis infection. BALB/c mice immunized with Lu. whitmani saliva developed robust humoral and cellular immune responses, the latter characterized by an intense cellular infiltrate and production of IFN-γ and IL-10, by both CD4+ and CD8+ cells. Mice immunized as above and challenged with L. braziliensis plus Lu. whitmani saliva displayed significantly smaller lesions and parasite load at the challenge site. This protection was associated with a higher (p<0.05) IFN-γ production in response to SLA stimulation. Long-term persisting immunity was also detected in mice immunized with Lu. whitmani saliva. Furthermore, individuals residing in an endemic area for cutaneous leishmaniasis (CL) presented antibody responses to Lu. whitmani saliva. However CL patients, with active lesions, displayed a lower humoral response to Lu. whitmani saliva compared to individuals with subclinical Leishmania infection. Pre-exposure to Lu. whitmani saliva induces protection against L. braziliensis in a murine model. We also show that Lu. whitmani salivary proteins are immunogenic in naturally exposed individuals. Our results reinforce the importance of investigating the immunomodulatory effect of saliva from different species of closely related sand flies.

  19. Experimental West Nile Virus Infection in Rabbits: An Alternative Model for Studying Induction of Disease and Virus Control

    Directory of Open Access Journals (Sweden)

    Willy W. Suen

    2015-07-01

    Full Text Available The economic impact of non-lethal human and equine West Nile virus (WNV disease is substantial, since it is the most common presentation of the infection. Experimental infection with virulent WNV strains in the mouse and hamster models frequently results in severe neural infection and moderate to high mortality, both of which are not representative features of most human and equine infections. We have established a rabbit model for investigating pathogenesis and immune response of non-lethal WNV infection. Two species of rabbits, New Zealand White (Oryctolagus cuniculus and North American cottontail (Sylvilagus sp., were experimentally infected with virulent WNV and Murray Valley encephalitis virus strains. Infected rabbits exhibited a consistently resistant phenotype, with evidence of low viremia, minimal-absent neural infection, mild-moderate neuropathology, and the lack of mortality, even though productive virus replication occurred in the draining lymph node. The kinetics of anti-WNV neutralizing antibody response was comparable to that commonly seen in infected horses and humans. This may be explained by the early IFNα/β and/or γ response evident in the draining popliteal lymph node. Given this similarity to the human and equine disease, immunocompetent rabbits are, therefore, a valuable animal model for investigating various aspects of non-lethal WNV infections.

  20. Experimental West Nile Virus Infection in Rabbits: An Alternative Model for Studying Induction of Disease and Virus Control

    Science.gov (United States)

    Suen, Willy W.; Uddin, Muhammad J.; Wang, Wenqi; Brown, Vienna; Adney, Danielle R.; Broad, Nicole; Prow, Natalie A.; Bowen, Richard A.; Hall, Roy A.; Bielefeldt-Ohmann, Helle

    2015-01-01

    The economic impact of non-lethal human and equine West Nile virus (WNV) disease is substantial, since it is the most common presentation of the infection. Experimental infection with virulent WNV strains in the mouse and hamster models frequently results in severe neural infection and moderate to high mortality, both of which are not representative features of most human and equine infections. We have established a rabbit model for investigating pathogenesis and immune response of non-lethal WNV infection. Two species of rabbits, New Zealand White (Oryctolagus cuniculus) and North American cottontail (Sylvilagus sp.), were experimentally infected with virulent WNV and Murray Valley encephalitis virus strains. Infected rabbits exhibited a consistently resistant phenotype, with evidence of low viremia, minimal-absent neural infection, mild-moderate neuropathology, and the lack of mortality, even though productive virus replication occurred in the draining lymph node. The kinetics of anti-WNV neutralizing antibody response was comparable to that commonly seen in infected horses and humans. This may be explained by the early IFNα/β and/or γ response evident in the draining popliteal lymph node. Given this similarity to the human and equine disease, immunocompetent rabbits are, therefore, a valuable animal model for investigating various aspects of non-lethal WNV infections. PMID:26184326

  1. Is Salvage of Recently Infected Breast Implant After Breast Augmentation or Reconstruction Possible? An Experimental Study.

    Science.gov (United States)

    Castus, P; Heymans, O; Melin, P; Renwart, L; Henrist, C; Hayton, E; Mordon, S; Leclère, F M

    2018-01-23

    The reinsertion of an infected implant when peri-prosthetic infection occurs early after breast augmentation or breast reconstruction remains controversial. In this experimental study, the authors tried to remove bacteria, and their biofilm, from the colonized surface of breast prostheses, without damaging their integrity. A total of 112 shell samples of silicone breast prostheses, smooth (SPSS) and textured (TPSS), were colonized by S. epidermidis (SE) or S. aureus (SA) strains, all able to produce biofilms. After 15 days, all the samples were removed from the contaminated culture broth and constituted 4 groups of 20 contaminated samples: SPSS/SE (group I), SPSS/SA (group II), TPSS/SE (group III), TPSS/SE (group IV). In another group-group SEM-, 16 colonized samples were used for documentation with scanning electron microscopy (SEM). The remaining 16 samples were used to test the limits of detection of the sterility test. All samples of groups I-IV and 8 samples of group SEM were « washed » with a smooth brush in a povidone-iodine bath and rinsed with saline solution. A subset of the washed samples was sent for SEM and the others were immersed in sterile broth and were incubated at 35 °C for 3 weeks (groups I-IV). Fifteen days after contamination, all the samples in groups I-IV were colonized. In the SEM group, SEM images attested to the presence of bacteria in biofilm attached to the shells. After cleaning, SEM did not reveal any bacteria and there was no visible alteration in the outer structure of the shell. Sterility tests performed after decontamination in groups I-IV remained negative for all the samples. Breast prostheses recently contaminated with Staphylococci, frequently involved in peri-prosthetic breast implant infection and capable of producing biofilms, can be efficiently decontaminated by the procedure used in this study. Our decontamination procedure did not alter the surface structure of the prostheses. This decontamination procedure

  2. Biochemical studies in experimentally Escherichia coli infected broiler chicken supplemented with neem (Azadirachta indica leaf extract

    Directory of Open Access Journals (Sweden)

    Vikash Sharma

    2015-11-01

    Full Text Available Aim: An experimental study was conducted on 192-day-old broiler chicks for evaluating the effect of 10% neem leaf extract (NLE supplementationon biochemical parameters in chickens experimentally infected with Escherichia coli O78 at 107 CFU/0.5 ml at 7 days of age. Materials and Methods: The 192-day-old broiler chicks were procured. These chicks were divided into two groups (A and B containing 96 birds each on the 1st day. Diet of all the chicks of Group A was supplemented with 10%NLE in water, whereas chicks of Group B were given feed and water devoid of NLE supplementation throughout the experiment. After rearing for 1 week, chicks of both the groups (A and B were again divided into two subgroups (Group A into A1 and A2 and Group B into B1 and B2 of 54 and 42 birds, respectively. At the age of 7 days all the chicks of groups A1 and B1 were injected with E. coli O78 at 107 CFU/0.5 ml intraperitoneally. Blood samples were collected from six chicks from each group at day 0, 2, 4, 7, 14, 21, 28 days post-infection and serum was separated for biochemical studies. Results: There was a significant increase in serum alanine transaminase (ALT, aspartate transaminase (AST, lactate dehydrogenase (LDH activities, globulin concentration and a decrease in total protein (TP, albumin concentrations, and alkaline phosphatase (ALP activity in both the infected groups. However, the changes in biochemical values, i.e., ALT, AST, LDH, ALP, TP, albumin, and globulin wereof lower magnitude in NLE supplemented group suggesting hepatoprotective and cardioprotective effect of NLE. Conclusions: Fromthe present study, it is reasonable to conclude that significant increase in the value of ALT, AST, LDH, globulin, and significant decrease in the value of ALP, TP, and albumin was of lower magnitude in supplemented infected group (A1 as compared to non-supplemented infected group (B1 suggesting hepatoprotective and cardioprotective effect of NLE.

  3. Airway inflammation and illness severity in response to experimental rhinovirus infection in asthma.

    Science.gov (United States)

    Zhu, Jie; Message, Simon D; Qiu, Yusheng; Mallia, Patrick; Kebadze, Tatiana; Contoli, Marco; Ward, Christine K; Barnathan, Elliot S; Mascelli, Mary Ann; Kon, Onn M; Papi, Alberto; Stanciu, Luminita A; Jeffery, Peter K; Johnston, Sebastian L

    2014-06-01

    The nature of bronchial mucosal inflammation and its physiologic and clinical significance in rhinovirus-induced asthma exacerbations is unclear. We investigated bronchial mucosal inflammatory response and its association with physiologic and clinical outcomes in an experimental model of rhinovirus-induced asthma exacerbations. We used immunohistochemistry methods to detect phenotypes of inflammatory cells infiltrating the bronchial mucosa before and after experimental rhinovirus infection in 10 subjects with asthma and 15 normal subjects. Compared with baseline, rhinovirus infection significantly increased the number of epithelial (P = .005) and subepithelial (P = .017) neutrophils in subjects with asthma only and subepithelial CD68+ macrophages in both subjects with asthma (P = .009) and normal subjects (P = .018) but more so in those with asthma (P = .021). Numbers of CD45+, CD68+, and CD20+ cells; neutrophils; and eosinophils at day 4 postinfection were positively associated with virus load (r = 0.50-0.72, P = .016-0.03). At acute infection in subjects with asthma, CD4+ cells correlated with chest symptom scores (r = 0.69, P = .029), the fall in the 10% fall in FEV1 (PC10) correlated with neutrophils (r = -0.89, P = .029), the PC10 correlated inversely with CD4+ (r = -0.67, P = .023) and CD8+ cells (r = -0.65, P = .03), the 20% fall in FEV1 was inversely associated with CD20+ cells (r = -0.65, P = .03), and higher epithelial CD8+ cell counts were significantly associated with a greater maximum fall in FEV1 (r = -0.72, P = .03), whereas higher subepithelial mast cell counts were significantly associated with a lower maximum percent fall in peak expiratory flow (r = 0.8, P = .024). In subjects with asthma, rhinovirus infection induces bronchial mucosal neutrophilia and more severe monocyte/macrophage infiltration than in normal subjects. Airway neutrophils, eosinophils, and T and B lymphocytes during infection are related to virus load and physiologic and

  4. Experimental Hyalohyphomycosis by Purpureocillium lilacinum: Outcome of the Infection in C57BL/6 Murine Models

    Directory of Open Access Journals (Sweden)

    Danielly C. M. de Sequeira

    2017-08-01

    Full Text Available Purpureocillium lilacinum is a filamentous, hyaline fungus considered an emerging pathogen in humans. The aim of our study was to evaluate the outcome of hyalohyphomycosis in C57BL/6 murine models inoculated with two clinical P. lilacinum isolates (S1 and S2. Each isolate was inoculated in mice randomly distributed in immunocompetent (CPT and immunosuppressed (SPS groups. Mice were evaluated at day 7, 21, and 45 after inoculation for histopathological analysis, recovery of fungal cells, and immunological studies. Histological analysis showed scarce conidia-like structures in lung tissue from CPT mice and a lot of fungal cells in SPS mice inoculated with S2 compared to mice inoculated with S1. The maximum recovery of fungal cells was seen in CPT mice inoculated with both isolates at day 7, but with mean significantly higher in those inoculated with S2 isolate. Phenotypical characterization of T cells showed TCD8+ lymphocytes predominance over TCD4+ in immunosuppressed mice infected and control groups. We also observed higher percentages of the central and effector memory/effector phenotype in CPT mice infected with S2 strain, especially in TCD8+ in the initial period of infection. Regulatory T cells showed higher percentages in immunosuppressed, predominantly after the acute phase. Our results showed that the P. lilacinum is a fungus capable to cause damages in competent and immunosuppressed experimental hosts. Furthermore, S2 isolate seems to cause more damage to the experimental host and it was possible to identify different cellular subsets involved in the mice immune response.

  5. Histopathological, immunohistochemical, and molecular study of BHV-5 infection in the central nervous system of experimentally infected calves

    Directory of Open Access Journals (Sweden)

    Didier Q. Cagnini

    2015-04-01

    Full Text Available Bovine meningoencephalitis caused by BHV-5, a double-stranded DNA enveloped virus that belongs to the family Herpesviridae and subfamily Alphaherpesvirinae, is an important differential diagnosis of central nervous diseases. The aim of this study was to describe the histological changes in the central nervous system of calves experimentally infected with BHV-5 and compare these changes with the PCR and IHC results. Formalin-fixed paraffin-embedded central nervous system samples from calves previously inoculated with BHV-5 were microscopically evaluated and tested using IHC and PCR. All the animals presented with nonsuppurative meningoencephalitis. From 18 evaluated areas of each calf, 32.41% and 35.19% were positive by IHC and PCR, respectively. The telencephalon presented more accentuated lesions and positive areas in the PCR than other encephalic areas and was the best sampling area for diagnostic purposes. Positive areas in the IHC and PCR were more injured than IHC and PCR negative areas. The animal with neurological signs showed more PCR- and IHC-positive areas than the other animals.

  6. Infecção experimental por Trypanosoma vivax em ovinos Experimental infection by Trypanosoma vivax in sheep

    Directory of Open Access Journals (Sweden)

    Jael Soares Batista

    2006-03-01

    Full Text Available O presente estudo teve por objetivo avaliar as alterações clínicas, hematológicas e patológicas em ovinos infectados experimentalmente com Trypanosoma vivax, utilizando-se um isolado proveniente de bovinos infectados naturalmente no município de Catolé do Rocha, Paraíba. Quatro ovinos da raça Santa Inês foram infectados por via intravenosa com 1ml de sangue contendo 1,85x10(5 tripomastigotas de T. vivax e outros quatro ovinos foram destinados ao grupo controle. A parasitemia e a temperatura foram determinadas diariamente durante 30 dias após a infecção (dpi e quinzenalmente dos 31 aos 90 dias. A cada 15 dias os animais foram pesados e realizados coletas de sangue para hemograma. Um ovino morreu aos 75 dpi, os demais animais do grupo infectado e do grupo controle foram sacrificados 90 dias após o início do experimento. T. vivax foi evidenciado a partir do 4º dpi em todos os ovinos infectados. A parasitemia foi constante até os 15 dias e irregular entre os 16 e 30 dias. Após o 30º dia não foram observados parasitas no sangue. Foi observada correlação linear positiva entre temperatura retal e parasitemia [Y=0,027x + 38,515; R²=0,9444 (PThis paper has the objective to report clinical signs, hematologic changes, and macroscopic and microscopic alterations in sheep infected experimentally with Trypanosoma vivax, isolated from an outbreak in cattle in the semiarid region of the state of Paraíba, northeastern Brazil. Four Santa Inês sheep were inoculated intravenously with 1ml of blood containing 1.85x10(5 trypomastigotes. Other 4 sheep were used as control. The presence of trypanosomes in the blood and the temperature were recorded daily during the first 30 days and fortnightly from day 31 to day 90 after infection. Also fortnightly, the sheep were weighed and blood samples were obtained for hematological analysis. One inoculated sheep died 75 days after inoculation. The other 3 inoculated and the 4 control sheep were killed 90

  7. Species-specific immunity induced by infection with Entamoeba histolytica and Entamoeba moshkovskii in mice.

    Science.gov (United States)

    Shimokawa, Chikako; Culleton, Richard; Imai, Takashi; Suzue, Kazutomo; Hirai, Makoto; Taniguchi, Tomoyo; Kobayashi, Seiki; Hisaeda, Hajime; Hamano, Shinjiro

    2013-01-01

    Entamoeba histolytica, the parasitic amoeba responsible for amoebiasis, causes approximately 100,000 deaths every year. There is currently no vaccine against this parasite. We have previously shown that intracecal inoculation of E. histolytica trophozoites leads to chronic and non-healing cecitis in mice. Entamoeba moshkovskii, a closely related amoeba, also causes diarrhea and other intestinal disorders in this model. Here, we investigated the effect of infection followed by drug-cure of these species on the induction of immunity against homologous or heterologous species challenge. Mice were infected with E. histolytica or E. moshkovskii and treated with metronidazole 14 days later. Re-challenge with E. histolytica or E. moshkovskii was conducted seven or 28 days following confirmation of the clearance of amoebae, and the degree of protection compared to non-exposed control mice was evaluated. We show that primary infection with these amoebae induces a species-specific immune response which protects against challenge with the homologous, but not a heterologous species. These findings pave the way, therefore, for the identification of novel amoebae antigens that may become the targets of vaccines and provide a useful platform to investigate host protective immunity to Entamoeba infections.

  8. Sensitivity and specificity of parallel or serial serological testing for detection of canine Leishmania infection

    Directory of Open Access Journals (Sweden)

    Mauro Maciel de Arruda

    2016-01-01

    Full Text Available In Brazil, human and canine visceral leishmaniasis (CVL caused byLeishmania infantum has undergone urbanisation since 1980, constituting a public health problem, and serological tests are tools of choice for identifying infected dogs. Until recently, the Brazilian zoonoses control program recommended enzyme-linked immunosorbent assays (ELISA and indirect immunofluorescence assays (IFA as the screening and confirmatory methods, respectively, for the detection of canine infection. The purpose of this study was to estimate the accuracy of ELISA and IFA in parallel or serial combinations. The reference standard comprised the results of direct visualisation of parasites in histological sections, immunohistochemical test, or isolation of the parasite in culture. Samples from 98 cases and 1,327 noncases were included. Individually, both tests presented sensitivity of 91.8% and 90.8%, and specificity of 83.4 and 53.4%, for the ELISA and IFA, respectively. When tests were used in parallel combination, sensitivity attained 99.2%, while specificity dropped to 44.8%. When used in serial combination (ELISA followed by IFA, decreased sensitivity (83.3% and increased specificity (92.5% were observed. Serial testing approach improved specificity with moderate loss in sensitivity. This strategy could partially fulfill the needs of public health and dog owners for a more accurate diagnosis of CVL.

  9. The Plasmodium falciparum-specific human memory B cell compartment expands gradually with repeated malaria infections.

    Directory of Open Access Journals (Sweden)

    Greta E Weiss

    2010-05-01

    Full Text Available Immunity to Plasmodium falciparum (Pf malaria is only acquired after years of repeated infections and wanes rapidly without ongoing parasite exposure. Antibodies are central to malaria immunity, yet little is known about the B-cell biology that underlies the inefficient acquisition of Pf-specific humoral immunity. This year-long prospective study in Mali of 185 individuals aged 2 to 25 years shows that Pf-specific memory B-cells and antibodies are acquired gradually in a stepwise fashion over years of repeated Pf exposure. Both Pf-specific memory B cells and antibody titers increased after acute malaria and then, after six months of decreased Pf exposure, contracted to a point slightly higher than pre-infection levels. This inefficient, stepwise expansion of both the Pf-specific memory B-cell and long-lived antibody compartments depends on Pf exposure rather than age, based on the comparator response to tetanus vaccination that was efficient and stable. These observations lend new insights into the cellular basis of the delayed acquisition of malaria immunity.

  10. Plasma and tissue pharmacokinetics of marbofloxacin in experimentally infected chickens with Mycoplasma gallisepticum and Escherichia coli.

    Science.gov (United States)

    Ding, H; Wang, L; Shen, X; Gu, X; Zeng, D; Zeng, Z

    2013-10-01

    The plasma and tissue pharmacokinetics of marbofloxacin in chickens experimentally infected with Mycoplasma gallisepticum and Escherichia coli were studied. Marbofloxacin was given to 66 infected chickens by oral administration at a dosage of 5 mg/kg b.w., once a day for three days. Plasma, brain, kidney, liver, lung, muscle and trachea were collected and marbofloxacin concentrations were analyzed by a high performance liquid chromatography method. In the infected chickens, maximal marbofloxacin concentrations in plasma, brain, kidney, liver, lung, muscle and trachea were 1.84, 1.33, 7.35, 5.61, 3.12, 2.98, and 4.51 g/mL (g); the elimination half-lives of marbofloxacin were 6.8, 2.74, 9.31, 8.45, 9.55, 11.53 and 5.46 h for plasma, brain, kidney, liver, lung, muscle and trachea, respectively. AUC were calculated to be 9.68, 8.04, 45.1, 27.03, 20.56, 19.47, and 32.68 μg/mL (g) for plasma, brain, kidney, liver, lung, muscle and trachea, respectively. Marbofloxacin concentration in tissues except for brain exceeded marbofloxacin concentration in plasma, with AUC(tissue) /AUC(plasma) ranging from 2.01 to 4.66 and Peak(tissue) /Peak(plasma) ranging from 1.62 to 3.99. The results showed that a marbofloxacin dosage of 5 mg/kg administered orally at 24 h intervals may provide successful treatment of chicken with MG and E. coli infection. © 2013 John Wiley & Sons Ltd.

  11. Restricted expression of Borna disease virus glycoprotein in brains of experimentally infected Lewis rats.

    Science.gov (United States)

    Werner-Keiss, N; Garten, W; Richt, J A; Porombka, D; Algermissen, D; Herzog, S; Baumgärtner, W; Herden, C

    2008-12-01

    Borna disease virus (BDV) induces a persistent infection in the central nervous system (CNS) accompanied by a non-purulent meningoencephalitis. BDV-infection of Lewis rats provides an important model to investigate basic principles of neurotropism, viral persistence and resulting dysfunctions. To date, the in vivo strategies of BDV to persist in the CNS are not fully understood. Viral glycoproteins are main targets of the antiviral defence implicating a controlled expression in case of persistent infections. Therefore, we analysed the expression profiles of the BDV-glycoprotein (BDV-GP) and corresponding BDV-intron II RNA in experimentally infected rat brains, focusing on their spatio-temporal occurrence, regional, cellular and intracellular locations. This was carried out by immunohistochemistry and in situ hybridization. The expression pattern of the most abundantly expressed BDV-nucleoprotein (BDV-N) served as a reference. BDV-N mRNA was detected preferentially in the cytoplasm of neurones, whereas BDV-intron II mRNA was found predominantly in the nucleus of brain cells. The genomic RNA was restricted to the nucleus. Expression of BDV-GP was significantly lower than BDV-N expression and mainly limited to cerebral cortex, hippocampus, amygdala and thalamus. BDV-GP was restricted to larger neurones; BDV-N occurred also in astrocytes, oligodendrocytes and ependymal cells. The expression profiles of BDV-GP, BDV-N and their mRNAs are significantly different, indicating that BDV-GP expression is regulated in vivo. This might be achieved by restricted nuclear export and/or maturation of BDV-intron II mRNA or limited translation as a viral mechanism to escape from the immune response and enable persistence in the CNS.

  12. Sensitivities, Specificities, and Predictive Values of Microbiological Culture Techniques for the Diagnosis of Prosthetic Joint Infection

    Directory of Open Access Journals (Sweden)

    Robert W. Jordan

    2014-01-01

    Full Text Available Background. Identifying the microorganism in a prosthetic joint infection is the key to appropriately targeting antimicrobial treatment. Despite the availability of various techniques, no single test is considered the definitive gold standard. Aim. Our aim was to determine the sensitivity, specificity, and positive/negative predictive values for a variety of culture techniques. Methods. We performed a retrospective case series of 219 patients undergoing revision surgery of their hip or knee replacement between May 2004 and February 2013. The patients were classified as either infected or noninfected according to criteria set out by the Musculoskeletal Infection Society. The number and type of samples taken intraoperatively varied between cases but included tissue samples and fluid sent in either blood culture vials or sterile containers. Results. The highest sensitivity was found with blood culture vials (0.85 compared to fluid in sterile containers (0.26 and tissues samples (0.32. Blood culture vials also had a better specificity and positive and negative predictive values profile. Conclusion. We conclude that, of the techniques studied, fluid in blood culture vials had the best profile for the correct identification of microorganisms and advocate its use.

  13. Sensitivities, Specificities, and Predictive Values of Microbiological Culture Techniques for the Diagnosis of Prosthetic Joint Infection

    Science.gov (United States)

    Jordan, Robert W.; Smith, Nicholas A.; Sprowson, Andrew P.

    2014-01-01

    Background. Identifying the microorganism in a prosthetic joint infection is the key to appropriately targeting antimicrobial treatment. Despite the availability of various techniques, no single test is considered the definitive gold standard. Aim. Our aim was to determine the sensitivity, specificity, and positive/negative predictive values for a variety of culture techniques. Methods. We performed a retrospective case series of 219 patients undergoing revision surgery of their hip or knee replacement between May 2004 and February 2013. The patients were classified as either infected or noninfected according to criteria set out by the Musculoskeletal Infection Society. The number and type of samples taken intraoperatively varied between cases but included tissue samples and fluid sent in either blood culture vials or sterile containers. Results. The highest sensitivity was found with blood culture vials (0.85) compared to fluid in sterile containers (0.26) and tissues samples (0.32). Blood culture vials also had a better specificity and positive and negative predictive values profile. Conclusion. We conclude that, of the techniques studied, fluid in blood culture vials had the best profile for the correct identification of microorganisms and advocate its use. PMID:24963476

  14. Latex protein extracts from Calotropis procera with immunomodulatory properties protect against experimental infections with Listeria monocytogenes.

    Science.gov (United States)

    Nascimento, Danielle Cristina de Oliveira; Ralph, Maria Taciana; Batista, Jacqueline Ellen Camelo; Silva, Diogo Manoel Farias; Gomes-Filho, Manoel Adrião; Alencar, Nylane Maria; Leal, Nilma Cintra; Ramos, Márcio Viana; Lima-Filho, Jose Vitor

    2016-06-15

    The latex from the medicinal plant Calotropis procera is often used in folk medicine against infectious and inflammatory diseases. In this study, we investigate a protein fraction with immunomodulatory properties, named LPPI, against experimental infections, in vitro and in vivo, with a virulent strain of Listeria monocytogenes. LPPI was exposed to cultured macrophages or Swiss mice and then challenged with L. monocytogenes. Peritoneal macrophages were obtained from Swiss mice, and cultured in 96-well microplates. Soluble latex proteins (LP) were subjected to fractionation by ion-exchange chromatography. The major peak (LPPI) was added into wells at 10 or 100µg/ml. Albumin (100µg/ml) was used for comparison between protein treatments. After incubation for 1h at 5% CO2/ 37°C, the supernatant was discarded and 0.2ml of L. monocytogenes overnight culture was added in the wells. Following 4h and 24h infection, the cytokine mRNA expression was evaluated as well as the number of intracellular colony forming units. Swiss mice (n=16) were injected intraperitoneally (i.p.) with LPPI (5 and 10mg/kg) while the control mice received albumin (10mg/kg) or LP (10mg/kg). After 24h, all animal groups were challenged with L. monocytogenes (10(6) CFU/ ml), also by i.p. route. LPPI was not toxic to uninfected macrophages (pMØ) and significantly increased mRNA expression of TNF-α, IL-6, IL-1β and iNOS. Following infection, cell viability was reduced by 50% in albumin-treated pMØ (control); but only 17% in pMØ treated with LPPI at 100µg/ml. In this case, LPPI increased expression of TNF-α and IL-6 whereas the number of bacterial colony-forming units was reduced 100-fold in comparison to control groups. Swiss mice pretreated with LPPI showed dose-dependent survival rates that reached 80%, while mice that received albumin died 1-3 days after infection. After 24h infection, leukocyte migration to the infectious foci was high in LPPI-treated mice whereas the number of viable

  15. Induction of Gag-Specific CD4 T Cell Responses during Acute HIV Infection Is Associated with Improved Viral Control

    Science.gov (United States)

    Schieffer, Miriam; Jessen, Heiko K.; Oster, Alexander F.; Pissani, Franco; Soghoian, Damien Z.; Lu, Richard; Jessen, Arne B.; Zedlack, Carmen; Schultz, Bruce T.; Davis, Isaiah; Ranasinghe, Srinika; Rosenberg, Eric S.; Alter, Galit; Schumann, Ralf R.

    2014-01-01

    ABSTRACT Effector CD4 T cell responses have been shown to be critically involved in the containment and clearance of viral pathogens. However, their involvement in the pathogenesis of HIV infection is less clear, given their additional role as preferred viral targets. We previously demonstrated that the presence of HIV-specific CD4 T cell responses is somewhat associated with HIV control and that specific CD4 T cell functions, such as direct cytolytic activity, can contribute to control of HIV viremia. However, little is known about how the induction of HIV-specific CD4 T cell responses during acute HIV infection influences disease progression and whether responses induced during the early phase of infection are preferentially depleted. We therefore longitudinally assessed, in a cohort of 55 acutely HIV-infected individuals, HIV-specific CD4 T cell responses from acute to chronic infection. Interestingly, we found that the breadth, magnitude, and protein dominance of HIV-specific CD4 T cell responses remained remarkably stable over time. Moreover, we found that the epitopes targeted at a high frequency in acute HIV infection were recognized at the same frequency by HIV-specific CD4 T cells in chronic HIV infection. Interestingly the induction of Gag-specific CD4 T cell responses in acute HIV infection was significantly inversely correlated with viral set point in chronic HIV infection (R = −0.5; P = 0.03), while the cumulative contribution of Env-specific CD4 T cell responses showed the reverse effect. Moreover, individuals with HIV-specific CD4 T cell responses dominantly targeting Gag over Env in acute HIV infection remained off antiretroviral therapy significantly longer (P = 0.03; log rank). Thus, our data suggest that the induction of HIV-specific CD4 T cell responses during acute HIV infection is beneficial overall and does not fuel disease progression. IMPORTANCE CD4 T cells are critical for the clearance and control of viral infections. However, HIV

  16. Molecular characterisation of the early response in pigs to experimental infection with Actinobacillus pleuropneumoniae using cDNA microarrays

    DEFF Research Database (Denmark)

    Hedegaard, Jakob; Skovgaard, Kerstin; Mortensen, Shila

    2007-01-01

    of this study was hence to characterise the transcriptional response, measured by using cDNA microarrays, in pigs 24 hours after experimental inoculation with A. pleuropneumoniae. Methods: Microarray analyses were conducted to reveal genes being differentially expressed in inflamed versus non-inflamed lung......-infected animals and 130 genes differed in expression in tracheobronchial lymph node tissue from infected versus non-infected animals. Among these genes, several have previously been described to be part of a general host response to infections encoding immune response related proteins. In inflamed lung tissue...

  17. Influence of etoposide and cyclophosphamide on the efficacy of cloxacillin and erythromycin in an experimental staphylococcal infection.

    Science.gov (United States)

    Calame, W; van der Waals, R; Mattie, H; van Furth, R

    1989-01-01

    The effect of monocytopenia and granulocytopenia on the outgrowth of Staphylococcus aureus as well as on antibiotic efficacy was studied in an experimental thigh infection in mice. Pretreatment with etoposide reduced monocyte numbers in blood to 14% and those of granulocytes to 54% at the time of infection. Monocytopenia did not affect the proliferation of bacteria in the infected thigh or the reduction of bacterial numbers after treatment with cloxacillin or erythromycin. Pretreatment with cyclophosphamide reduced monocyte numbers to 15% and granulocyte numbers to 3%. This resulted in a marked increase in the number of bacteria at the site of infection and a decrease in the efficacy of antibiotic treatment. PMID:2764550

  18. EXPERIMENTAL CHALLENGE STUDY OF FV3-LIKE RANAVIRUS INFECTION IN PREVIOUSLY FV3-LIKE RANAVIRUS INFECTED EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA) TO ASSESS INFECTION AND SURVIVAL.

    Science.gov (United States)

    Hausmann, Jennifer C; Wack, Allison N; Allender, Matthew C; Cranfield, Mike R; Murphy, Kevin J; Barrett, Kevin; Romero, Jennell L; Wellehan, James F X; Blum, Stella A; Zink, M Christine; Bronson, Ellen

    2015-12-01

    The Maryland Zoo in Baltimore experienced an outbreak of Frog virus-3 (FV3)-like ranavirus during the summer of 2011, during which 14 of 27 (52%) of its captive eastern box turtles (Terrapene carolina carolina) survived. To assess survival, immunity, and viral shedding, an experimental challenge study was performed in which the surviving, previously infected turtles were reinfected with the outbreak strain of FV3-like ranavirus. Seven turtles were inoculated with virus intramuscularly and four control turtles received saline intramuscularly. The turtles were monitored for 8 wk with blood and oral swabs collected for quantitative polymerase chain reaction (qPCR). During that time, one of seven (14%) inoculated turtles and none of the controls (0%) died; there was no significant difference in survival. Clinical signs of the inoculated turtles, except for the turtle that died, were mild compared to the original outbreak. Quantitative PCR for FV3-like ranavirus on blood and oral swabs was positive for all inoculated turtles and negative for all controls. The turtle that died had intracytoplasmic inclusion bodies in multiple organs. Three inoculated and two control turtles were euthanized at the end of the study. No inclusion bodies were present in any of the organs. Quantitative PCR detected FV3-like ranavirus in the spleen of a control turtle, which suggested persistence of the virus. The surviving five turtles were qPCR-negative for FV3-like ranavirus from blood and oral swabs after brumation. Quantitative PCR for Terrapene herpesvirus 1 found no association between ranavirus infection and herpesvirus loads. In conclusion, previously infected eastern box turtles can be reinfected with the same strain of FV3-like ranavirus and show mild to no clinical signs but can shed the virus from the oral cavity.

  19. Characteristics and specificity of acquired immunologic memory to Mycobacterium tuberculosis infection

    Energy Technology Data Exchange (ETDEWEB)

    Orme, I.M.

    1988-05-15

    The results herein show that mice infected with Mycobacterium tuberculosis and then exposed to a protracted course of isoniazid chemotherapy possess a heightened state of acquired resistance to subsequent challenge with the homologous organism. Our results provide the first evidence, moreover, that this resistance is mediated by a long-lived, cyclophosphamide- and irradiation-resistant L3T4+ Lyt-2- lymphocyte capable of giving rise to an accelerated re-emergence of resistance in the animal upon rechallenge. Evidence is also provided to show that triggering of this memory-immune T cell population in the re-challenged host was associated with the rapid emergence of non-specific resistance to secondary bacterial infection; however, the accelerated emergence of this population was only observed if the challenge inoculum consisted of the living organism. The relevance of this latter finding to strategies for vaccine development is discussed.

  20. Sex-specific immunization for sexually transmitted infections such as human papillomavirus: insights from mathematical models.

    Directory of Open Access Journals (Sweden)

    Johannes A Bogaards

    2011-12-01

    Full Text Available BACKGROUND: Sex-specific differences regarding the transmissibility and the course of infection are the rule rather than the exception in the epidemiology of sexually transmitted infections (STIs. Human papillomavirus (HPV provides an example: disease outcomes differ between men and women, as does the potential for transmission to the opposite sex. HPV vaccination of preadolescent girls was recently introduced in many countries, and inclusion of boys in the vaccination programs is being discussed. Here, we address the question of whether vaccinating females only, males only, or both sexes is the most effective strategy to reduce the population prevalence of an STI like HPV. METHODS AND FINDINGS: We use a range of two-sex transmission models with varying detail to identify general criteria for allocating a prophylactic vaccine between both sexes. The most effective reduction in the population prevalence of infection is always achieved by single-sex vaccination; vaccinating the sex with the highest prevaccine prevalence is the preferred strategy in most circumstances. Exceptions arise only when the higher prevaccine prevalence is due to a substantially lower rate of natural immunity, or when natural immunity is lifelong, and a prolonged duration of infectiousness coincides with increased transmissibility. Predictions from simple models were confirmed in simulations based on an elaborate HPV transmission model. Our analysis suggests that relatively inefficient genital transmission from males to females might render male vaccination more effective in reducing overall infection levels. However, most existing HPV vaccination programs have achieved sufficient coverage to continue with female-only vaccination. CONCLUSIONS: Increasing vaccine uptake among preadolescent girls is more effective in reducing HPV infection than including boys in existing vaccination programs. As a rule, directing prophylactic immunization at the sex with the highest

  1. High-Sensitivity Monoclonal Antibodies Specific for Homoserine Lactones Protect Mice from Lethal Pseudomonas aeruginosa Infections

    Science.gov (United States)

    Downham, Christina; Broadbent, Ian; Charlton, Keith; Porter, Andrew J.

    2014-01-01

    A number of bacteria, including pathogens like Pseudomonas aeruginosa, utilize homoserine lactones (HSLs) as quorum sensing (QS) signaling compounds and engage in cell-to-cell communication to coordinate their behavior. Blocking this bacterial communication may be an attractive strategy for infection control as QS takes a central role in P. aeruginosa biology. In this study, immunomodulation of HSL molecules by monoclonal antibodies (MAbs) was used as a novel approach to prevent P. aeruginosa infections and as tools to detect HSLs in bodily fluids as a possible first clue to an undiagnosed Gram-negative infection. Using sheep immunization and recombinant antibody technology, a panel of sheep-mouse chimeric MAbs were generated which recognized HSL compounds with high sensitivity (nanomolar range) and cross-reactivity. These MAbs retained their nanomolar sensitivity in complex matrices and were able to recognize HSLs in P. aeruginosa cultures grown in the presence of urine. In a nematode slow-killing assay, HSL MAbs significantly increased the survival of worms fed on the antibiotic-resistant strain PA058. The therapeutic benefit of these MAbs was further studied using a mouse model of Pseudomonas infection in which groups of mice treated with HSL-2 and HSL-4 MAbs survived, 7 days after pathogen challenge, in significantly greater numbers (83 and 67%, respectively) compared with the control groups. This body of work has provided early proof-of-concept data to demonstrate the potential of HSL-specific, monoclonal antibodies as theranostic clinical leads suitable for the diagnosis, prevention, and treatment of life-threatening bacterial infections. PMID:24185854

  2. Hematological and cerebrospinal fluid changes in cattle naturally and experimentally infected with the bovine herpesvirus 5

    Directory of Open Access Journals (Sweden)

    Júlio Augusto Naylor Lisbôa

    2009-11-01

    Full Text Available Bovine herpesvirus 5 (BoHV-5 meningoencephalitis is one of the main causes of mortality by encephalopathy in Brazilian cattle herds. However, the neurological signs observed are common to several encephalopathies and do not contribute decisively to a diagnosis. In order to verify hematological and cerebrospinal fluid (CSF changes, blood and CSF samples from naturally and experimentally infected bovines were evaluated. In natural cases (n=17, the samples were collected only once, and in experimental cases (n=7, the samples were sequentially obtained throughout disease progression. While routine methods were used to examine the samples, BoHV-5 infection was confirmed by a PCR assay. Blood analyses did not reveal any consistent hematological alterations and the leukogram results occasionally showed increases in leukocyte and segmented neutrophil. Hyperfibrinogenemia was noted in all experimentally infected calves and in half of the natural cases. Pleocytosis with mononuclear cells was a remarkable finding in CSF collected from both groups of animals and was present even in experimentally infected calves that remained asymptomatic. Therefore, CSF evaluation can be used as an auxiliary method in ante-mortem BoHV-5 diagnosis.A meningoencefalite determinada pelo herpesvírus bovino 5 (BoHV-5 é considerada uma das principais causas de mortalidade por encefalopatia em bovinos no Brasil. O diagnóstico clínico da infecção é difícil de ser realizado pois os sinais neurológicos ocasionados pela infecção com o BoHV-5 são comuns aos observados em encefalopatias bovinas de diferentes etiologias. Com o objetivo de determinar as alterações hematológicas e do líquido cefalorraquidiano, foram avaliadas amostras de sangue total e líquor colhidas de animais infectados tanto naturalmente quanto experimentalmente. Nos casos naturais da doença (n=17, as amostras foram coletadas apenas uma vez. Nos casos de infecção experimental (n=7, as amostras foram

  3. Necator americanus and helminth co-infections: further down-modulation of hookworm-specific type 1 immune responses.

    Directory of Open Access Journals (Sweden)

    Stefan Michael Geiger

    2011-09-01

    Full Text Available Helminth co-infection in humans is common in tropical regions of the world where transmission of soil-transmitted helminths such as Ascaris lumbricoides, Trichuris trichiura, and the hookworms Necator americanus and Ancylostoma duodenale as well as other helminths such as Schistosoma mansoni often occur simultaneously.We investigated whether co-infection with another helminth(s altered the human immune response to crude antigen extracts from either different stages of N. americanus infection (infective third stage or adult or different crude antigen extract preparations (adult somatic and adult excretory/secretory. Using these antigens, we compared the cellular and humoral immune responses of individuals mono-infected with hookworm (N. americanus and individuals co-infected with hookworm and other helminth infections, namely co-infection with either A. lumbricoides, Schistosoma mansoni, or both. Immunological variables were compared between hookworm infection group (mono- versus co-infected by bootstrap, and principal component analysis (PCA was used as a data reduction method.Contrary to several animal studies of helminth co-infection, we found that co-infected individuals had a further downmodulated Th1 cytokine response (e.g., reduced INF-γ, accompanied by a significant increase in the hookworm-specific humoral immune response (e.g. higher levels of IgE or IgG4 to crude antigen extracts compared with mono- infected individuals. Neither of these changes was associated with a reduction of hookworm infection intensity in helminth co-infected individuals. From the standpoint of hookworm vaccine development, these results are relevant; i.e., the specific immune response to hookworm vaccine antigens might be altered by infection with another helminth.

  4. Effect of photodynamic therapy (PDT) on Enterococcus faecalis biofilm in experimental primary and secondary endodontic infections.

    Science.gov (United States)

    Tennert, Christian; Feldmann, Katharina; Haamann, Edwina; Al-Ahmad, Ali; Follo, Marie; Wrbas, Karl-Thomas; Hellwig, Elmar; Altenburger, Markus J

    2014-11-04

    To determine the antibacterial effect of photodynamic Therapy on Enterococcus faecalis (E. faecalis) biofilms in experimentally infected human root canals in primary infections and endodontic retreatments. One hundred and sixty single-rooted extracted teeth with one root canal were prepared using ProTaper instruments. Seventy specimens were left without root canal filling and autoclaved. The root canals of another 70 specimens were filled with Thermafil and AH Plus and the root canal fillings were removed after 24 hours using ProTaper D files and plasma sterilized. The specimens were infected with a clinical isolate of E. faecalis for 72 hours. Samples were taken using sterile paper points to determine the presence of E. faecalis in the root canals. The specimens were randomly divided into groups according to their treatment with 20 teeth each and a control. In the PDT group the teeth were treated using PDT, consisting of the photosensitizer toluidine blue and the PDT light source at 635 nm. In the NaOCl (sodium hypochlorite) group the root canals were rinsed with 10 mL of 3% NaOCl. In the NaOCl-PDT group the root canals were rinsed with 10 mL of 3% of sodium hypochlorite and then treated with PDT. Samples were taken after treatments using sterile paper points. Additionally, remaining root canal filling material was recovered from the root canal walls. Survival fractions of the samples were calculated by counting colony-forming units. A one-way analysis of variance (ANOVA) was applied to the data to assess the effect of different treatment techniques. Antimicrobial treatment of root canals caused a significant reduction of bacterial load in all groups. NaOCl irrigation eliminated E. faecalis most effectively. PDT alone was less effective compared to NaOCl irrigation and the combination of NaOCl irrigation and PDT. CFU levels recovered from the filling material after NaOCl irrigation of the root canals were 10fold higher compared to PDT and the combination of Na

  5. Nosocomial infections in a Dutch neonatal intensive care unit: surveillance study with definitions for infection specifically adapted for neonates

    NARCIS (Netherlands)

    van der Zwet, W. C.; Kaiser, A. M.; van Elburg, R. M.; Berkhof, J.; Fetter, W. P. F.; Parlevliet, G. A.; Vandenbroucke-Grauls, C. M. J. E.

    2005-01-01

    The incidence of nosocomial infection in neonatal intensive care units (NICUs) is high compared with other wards. However, no definitions for hospital-acquired infection are available for NICUs. The aim of this study was to measure the incidence of such infections and to identify risk factors in the

  6. Pathology and viral antigen distribution following experimental infection of sheep and goats with capripoxvirus.

    Science.gov (United States)

    Embury-Hyatt, C; Babiuk, S; Manning, L; Ganske, S; Bowden, T R; Boyle, D B; Copps, J

    2012-01-01

    Current understanding of capripoxvirus pathogenesis is limited since there have been no detailed studies examining cell tropism at well-defined intervals following infection. We undertook time-course studies in sheep and goats following inoculation of sheeppox or goatpox viruses in their respective homologous hosts, and examined tissues by light microscopy. A monoclonal antibody generated to a sheeppox virus core protein was used for immunohistochemical detection of viral antigen in tissue sections. Lesions and virus antigen were observed consistently in the skin, lung and lymph nodes. Antigen was detected at 6 and 8 days post inoculation for skin and lung, respectively, within cells which appeared to be of monocyte/macrophage lineage. In sheep skin capripoxvirus immunoreactivity was detected within previously unreported large multinucleated cells. In the lung, double immunolabelling detected the simultaneous expression of capripoxvirus antigen and cytokeratin indicating the presence of virus within pneumocytes. Lung double immunolabelling also detected the expression of capripoxvirus antigen in CD68(+) cells, confirming the presence of viral antigen within macrophages. Based on early detection of infected macrophages, dissemination of virus within the host and localization to tissues likely occurred through cells of the monocyte/macrophage lineage. Histological findings revealed similarities with both monkeypox and smallpox, thus capripoxvirus infection in sheep and goats may represent useful models with which to study strategies for poxvirus-specific virus vaccine concepts and therapeutics. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  7. [Study on hepatocyte apoptosis of domestic pigs experimentally infected with Taenia asiatica and Taenia saginata].

    Science.gov (United States)

    Mou, Rong; Bao, Huai-En; Zhang, Ke; Wu, Jia-Hong; Lang, Shu-Yuan

    2012-10-30

    To investigate apoptosis in liver tissue of the domestic pigs infected with eggs of Taenia asiatica and Taenia saginata. The adult worms of T. asiatica and T. saginata were collected and identified from the taeniasis patients in Dunyun and Congjiang districts, Guizhou province. Eggs were collected from gravid proglottids and prepared by washing and centrifugation. Nineteen 20-day hybrid domestic pigs (Duroc-Yorkshire-Landrace strain) were randomly divided into T. asiatica group (6 pigs), T. saginata group (8 pigs) and control group (5 pigs). Each animal of experimental groups was infected with 1.5 x 10(5) eggs by stomach injection. On day 15, 32, 46 and 74 after infection, animals were sacrificed and liver samples were collected for further experiments. The liver tissues were sliced for glass slides and prepared for ultrathin sections. The apoptosis of hepatocytes was identified by terminal deoxynucleotidyl transferase-mediated dUTP nick and labeling. The morphological features of liver tissue were observed under transmission electron microscope. The infection rate of two experiment groups reached 100%. Better developed cysticerci were found in liver of T. asiatica group than that of T. saginata group, but the liver pathological changes caused by cysticerci were similar. On day 15 and 32 after infection, hydropic degeneration, obvious vacuolization and some balloon-like degeneration were found in hepatocytes, and focal hepatic necrosis was observed. On day 46, spotty necrosis occurred in some local liver tissues. On day 74, main damages were granulomatous reactions surrounding cysticercus and focal liver fibrosis. On day 46, apoptosis index in T. asiatica group [(15.07 +/- 3.42)6%] and T. saginata group [(17.13 +/- 1.62)5%] was considerably higher than that in the control [(9.53 +/- 1.06)%] (P saginata group [(34.20 +/- 0.73)%] was higher than that in the control [(13.60 +/- 2.26)%] (P saginata group was significantly higher than that of T. asiatica group (P

  8. Age related differences in dynamics of specific memory B cell populations after clinical pertussis infection.

    Directory of Open Access Journals (Sweden)

    Inonge van Twillert

    Full Text Available For a better understanding of the maintenance of immune mechanisms to Bordetella pertussis (Bp in relation to age, we investigated the dynamic range of specific B cell responses in various age-groups at different time points after a laboratory confirmed pertussis infection. Blood samples were obtained in a Dutch cross sectional observational study from symptomatic pertussis cases. Lymphocyte subpopulations were phenotyped by flowcytometry before and after culture. Memory B (Bmem cells were differentiated into IgG antibody secreting cells (ASC by polyclonal stimulation and detected by an ELISPOT assay specific for pertussis antigens pertussis toxin (Ptx, filamentous haemagglutinin (FHA and pertactin (Prn. Bp antigen specific IgG concentrations in plasma were determined using multiplex technology. The majority of subjects having experienced a clinical pertussis episode demonstrated high levels of both Bp specific IgG and Bmem cell levels within the first 6 weeks after diagnosis. Significantly lower levels were observed thereafter. Waning of cellular and humoral immunity to maintenance levels occurred within 9 months after antigen encounter. Age was found to determine the maximum but not base-line frequencies of Bmem cell populations; higher levels of Bmem cells specific for Ptx and FHA were reached in adults and (pre- elderly compared to under-fours and schoolchildren in the first 6 weeks after Bp exposure, whereas not in later phases. This age effect was less obvious for specific IgG levels. Nonetheless, subjects' levels of specific Bmem cells and specific IgG were weakly correlated. This is the first study to show that both age and closeness to last Bp encounter impacts the size of Bp specific Bmem cell and plasma IgG levels.

  9. Using experimental de-worming to measure the immunological and pathological impacts of lungworm infection in cane toads

    Directory of Open Access Journals (Sweden)

    Patrick B. Finnerty

    2017-12-01

    Full Text Available The immunological and pathological consequences of parasite infection can be more rigorously assessed from experimental manipulation than from correlational studies of natural infections. We used anthelmintic treatment to experimentally decrease intensities of lungworm infection in captive and free-ranging wild cane toads to assess parasite impacts on host immune responses. First, we administered the anthelmintic drug Ivermectin to both infected and uninfected toads, to distinguish drug effects per se from the impacts of killing lungworms. Worms began dying and decomposing <48 h after injection. The only immunological variables that were affected by anthelmintic treatment were bactericidal capacity of the blood which increased in parasitized toads (presumably triggered by decomposing worms in the lungs, and the phagocytic capacity of blood (which increased in both infected and uninfected toads; the latter effect presumably was caused by the injection of Ivermectin per se rather than removal of parasites. Second, we looked at correlates of variation in the infection intensity induced by de-worming (in both captive and free-ranging toads over an eight-week period. Heavier lungworm infection was associated with increased phagocytic ability of the host's blood, and a reduction in the host's liver mass (and hence, energy stores. Experimental de-worming thus revealed pathological and immunological costs of the presence of lungworms, and of their removal by anthelmintic injection. Keywords: Rhinella marina, Bufo marinus, Host, Parasite, Nematode

  10. Chikungunya Virus Infection and Acute Elevation of Serum Prostate-Specific Antigen

    Directory of Open Access Journals (Sweden)

    William Derval Aiken

    2015-01-01

    Full Text Available A man with prostate cancer on a regime of active surveillance had a laboratory-confirmed acute Chikungunya virus infection. The patient experienced a sudden increase in serum Prostate-Specific Antigen (PSA during the acute illness that caused him anxiety and confounded interpretation of the PSA test. Six weeks after the onset of Chikungunya Fever symptoms, the elevated serum PSA returned to baseline. The association of Chikungunya Fever and elevated serum PSA may result in misinterpretation of the PSA test, triggering unnecessary prostate biopsy or other management errors.

  11. Radioimmunoimaging of subacute infective endocarditis using a technetium-99m monoclonal granulocyte-specific antibody

    Energy Technology Data Exchange (ETDEWEB)

    Munz, D.L.; Sandrock, D.; Emrich, D. (Goettingen Univ. (Germany). Abt. fuer Nuklearmedizin); Morguet, A.J.; Heim, A.; Sold, G.; Figulla, H.R.; Kreuzer, H. (Goettingen Univ. (Germany). Abt. fuer Kardiologie und Pulmonologie)

    1991-12-01

    Immunoscintigraphy with a technetium-99m murine monoclonal IgG{sub 1} antibody directed against non-specific cross-reacting antigen (NCA-95) and carcinoembryonic antigen was performed with 20 patients with suspected subacute infective endocarditis (SIE) and 6 controls with suspected inflammatory/infectious disease elsewhere in the body. Immunoscintigraphy and echocardiography localised SIE in 11 of 15 patients in whom the disease could be confirmed. In 4 patients with validated SIE, the immunoscan was abnormal, and the echocardiogram was normal. In another 4 patients, the result was exactly the opposite. These findings suggest that the combination of immunoscintigraphy and echocardiography improves diagnostic efficacy in patients with suspected SIE. (orig.).

  12. Infective endocarditis: the specific features of its course, the criteria for diagnosis, differential diagnosis (part II

    Directory of Open Access Journals (Sweden)

    B S Belov

    2008-01-01

    Full Text Available Infective endocarditis (IE is today characterized by polyetiology due to a wide range of pathogens. The paper describes the specific features of the clinical picture of the disease in relation to the etiological agent, which have, in some cases, a crucial role in the choice of empiric antibiotic therapy. Significant clinical polymorphism, obscure symptoms, and monosyndromic onset as guises all enhance the importance of the differential diagnosis of IE, at its early stages in particular. Basic approaches to differentiating IE from the diseases in which differentially diagnostic problems arise to the utmost are outlined.

  13. Limits of variation, specific infectivity, and genome packaging of massively recoded poliovirus genomes

    Science.gov (United States)

    Song, Yutong; Liu, Ying; Mugavero, JoAnn; Shen, Sam H.; Ward, Charles B.; Asare, Emmanuel; Jiang, Ping; Paul, Aniko V.; Mueller, Steffen; Wimmer, Eckard

    2017-01-01

    Computer design and chemical synthesis generated viable variants of poliovirus type 1 (PV1), whose ORF (6,189 nucleotides) carried up to 1,297 “Max” mutations (excess of overrepresented synonymous codon pairs) or up to 2,104 “SD” mutations (randomly scrambled synonymous codons). “Min” variants (excess of underrepresented synonymous codon pairs) are nonviable except for P2Min, a variant temperature-sensitive at 33 and 39.5 °C. Compared with WT PV1, P2Min displayed a vastly reduced specific infectivity (si) (WT, 1 PFU/118 particles vs. P2Min, 1 PFU/35,000 particles), a phenotype that will be discussed broadly. Si of haploid PV presents cellular infectivity of a single genotype. We performed a comprehensive analysis of sequence and structures of the PV genome to determine if evolutionary conserved cis-acting packaging signal(s) were preserved after recoding. We showed that conserved synonymous sites and/or local secondary structures that might play a role in determining packaging specificity do not survive codon pair recoding. This makes it unlikely that numerous “cryptic, sequence-degenerate, dispersed RNA packaging signals mapping along the entire viral genome” [Patel N, et al. (2017) Nat Microbiol 2:17098] play the critical role in poliovirus packaging specificity. Considering all available evidence, we propose a two-step assembly strategy for +ssRNA viruses: step I, acquisition of packaging specificity, either (a) by specific recognition between capsid protein(s) and replication proteins (poliovirus), or (b) by the high affinity interaction of a single RNA packaging signal (PS) with capsid protein(s) (most +ssRNA viruses so far studied); step II, cocondensation of genome/capsid precursors in which an array of hairpin structures plays a role in virion formation. PMID:28973853

  14. Delayed protection by ESAT-6–specific effector CD4+ T cells after airborne M. tuberculosis infection

    Science.gov (United States)

    Gallegos, Alena M.; Pamer, Eric G.; Glickman, Michael S.

    2008-01-01

    Mycobacterium tuberculosis infection induces complex CD4 T cell responses that include T helper type 1 (Th1) cells and regulatory T cells. Although Th1 cells control infection, they are unable to fully eliminate M. tuberculosis, suggesting that Th1-mediated immunity is restrained from its full sterilizing potential. Investigation into T cell–mediated defense is hindered by difficulties in expanding M. tuberculosis–specific T cells. To circumvent this problem, we cloned CD4+ T cells from M. tuberculosis–infected B6 mice and generated transgenic mice expressing a T cell receptor specific for the immunodominant antigen early secreted antigenic target 6 (ESAT-6). Adoptively transferred naive ESAT-6–specific CD4+ T cells are activated in pulmonary lymph nodes between 7 and 10 d after aerosol infection and undergo robust expansion before trafficking to the lung. Adoptive transfer of activated ESAT-6–specific Th1 cells into naive recipients before aerosol M. tuberculosis infection dramatically enhances resistance, resulting in 100-fold fewer bacteria in infected lungs. However, despite large numbers of Th1 cells in the lungs of mice at the time of M. tuberculosis challenge, protection was not manifested until after 7 d following infection. Our results demonstrate that pathogen-specific Th1 cells can provide protection against inhaled M. tuberculosis, but only after the first week of infection. PMID:18779346

  15. Experimental infection of the bat tick Carios fonsecai (Acari: Ixodidae with the rabies virus

    Directory of Open Access Journals (Sweden)

    Silvana Regina Favoretto

    2013-12-01

    Full Text Available Introduction This study assessed the viability of the rabies virus in the argasid tick Carios fonsecai following experimental infection. Methods The mouse inoculation test (MIT, fluorescent antibody test (FAT and polymerase chain reaction (PCR were used. The rabies virus was administered to ticks via the intra-coelomic route, and the ticks were sacrificed at different time points. Results The inoculated ticks were negative for rabies according to the MIT. Ticks macerated with rabies virus were positive according to the MIT and FAT. All of the tick lots tested by PCR were positive. Conclusions The rabies virus became unviable shortly after its inoculation into tick bodies. Ticks are not likely to play an important role in the epidemiology of rabies.

  16. Infectious Diseases in Wild Animals in Utah VI. Experimental Infection of Birds with Rickettsia rickettsii

    Science.gov (United States)

    Lundgren, D. L.; Thorpe, B. D.; Haskell, C. D.

    1966-01-01

    Lundgren, D. L. (University of Utah, Salt Lake City), B. D. Thorpe, and C. D. Haskell. Infectious diseases in wild animals in Utah. VI. Experimental infection of birds with Rickettsia rickettsii. J. Bacteriol. 91:963–966. 1966.—Chickens, pigeons, pheasants, sparrow hawks, red-tailed hawks, ravens, magpies, and a marsh hawk were inoculated with Rickettsia rickettsii, the etiological agent of Rocky Mountain spotted fever. The development and persistence of complement-fixing (CF) antibodies and rickettsemias were tested for in these birds. Rickettsiae were recovered from the blood of a number of birds up to the 16th day after inoculation, whereas only the pigeon was found to develop high CF antibody titers. It was concluded that certain species of birds have the potential of contributing to the dissemination of R. rickettsii in nature, and that the CF test is generally unsuitable for serological diagnosis of this organism in birds. PMID:4956338

  17. [Experimental infection of fattening swine with rotavirus: study of local immunity using coproantibodies].

    Science.gov (United States)

    Bernard, S; Groom, J; Lantier, I

    1984-01-01

    Fattened pigs were experimentally infected with porcine rotavirus (OSU strain). Viral antigens found in the faeces were analysed over a period of two months (ELISA method). We have found no correlation between virus excretion and the clinical manifestation of disease. The local immunity has been analysed in the faeces by the coproantibodies antirotavirus. The different classes of antibody, G, M, A and immune complexes have been determined using the ELISA method. The level of IgA antibodies was higher (10 fold) than IgG and IgM, and the timing of the appearance of these antibodies antivirus was also different. No correlation was found between local immunity and virus excretion in the faeces.

  18. Experimental caprine neosporosis: the influence of gestational stage on the outcome of infection.

    Science.gov (United States)

    Porto, Wagnner José Nascimento; Regidor-Cerrillo, Javier; Kim, Pomy de Cássia Peixoto; Benavides, Julio; Silva, Ana Clécia dos Santos; Horcajo, Pilar; Oliveira, Andrea Alice da Fonseca; Ferre, Ignacio; Mota, Rinaldo Aparecido; Ortega-Mora, Luis Miguel

    2016-02-11

    Here, we assessed outcome of experimental infection by Neospora caninum in goats intravenously inoculated with 10(6) tachyzoites of the Nc-Spain7 isolate at 40 (G1), 90 (G2) and 120 (G3) days of gestation. Infected goats had fever between 5 and 9 days post inoculation (dpi); all were seropositive at the time of abortion/birth. Foetal death occurred in G1 from 10 to 21 dpi (n = 7) and in G2 from 27 to 35 dpi (n = 4). Goats in G2 also had seropositive stillbirth (n = 1) and healthy kids (n = 2). G3 goats (n = 7) had 3 seropositive and 3 seronegative weak kids, and 2 seronegative healthy kids. Parasite DNA detection in placentomes was 100% in G2, 85.7% in G3 and in G1 was detected only in placentomes from the goats with foetal losses from 17 dpi (100%). Parasites were detected in foetal/kid brain (>85.7%) and liver (≥ 50%) of G2 and G3, and in G1 after 17 dpi (100%). The highest parasite loads were detected in the placentomes of G1 from 17 dpi and G2, and in foetal tissues of G1 from 17 dpi and G3. Multifocal necrotic lesions were observed in the placentas of the three groups, but they were larger and more frequent in G1 and G2. Similar lesions were observed in foetal tissues, but they were more frequent in G3. These findings suggest that, as observed in cattle and sheep, the clinical consequences of N. caninum in pregnant goats are dependent in part on the time of gestation when animals were infected.

  19. Human rhinovirus in experimental infection after peroral Lactobacillus rhamnosus GG consumption, a pilot study.

    Science.gov (United States)

    Tapiovaara, Laura; Kumpu, Minna; Mäkivuokko, Harri; Waris, Matti; Korpela, Riitta; Pitkäranta, Anne; Winther, Birgit

    2016-08-01

    Data has emerged on possible beneficial effects of probiotics in respiratory tract viral infections, but it is unclear if the promising positive effects evidenced are due to a reduced viral load during infections. The aims of this work were to investigate the effect of peroral probiotic Lactobacillus rhamnosus GG (American Type Culture Collection [ATCC], Accession No. 53103) consumption on human rhinovirus (HRV) load in nasopharyngeal lavage samples in experimental HRV infection, and to correlate viral load to clinical symptoms. Intranasal HRV A39 inoculation was performed on 59 adults, who had consumed juice enriched with live or heat-inactivated L. rhamnosus GG or control juice for 3 weeks prior to inoculation in a randomized, controlled, pilot trial setting. Nasopharyngeal lavage samples and symptom data were analyzed on day 0 before inoculation, and on days 2 and 5. Samples were subjected to quantitative HRV detection by polymerase chain reaction (PCR). Before inoculation 9 of 59 (15%) samples presented with another HRV strain than the studied A39. There was a tendency toward the lowest HRV loads in the L. rhamnosus GG groups and the highest in placebo group (log10 copies/mL, 95% confidence interval [CI], 6.20 [5.18 to 7.40] in live, 6.30 [4.91 to 7.08] in inactivated L. rhamnosus GG, and 7.25 [5.81 to 7.52] in placebo group, p = 0.57 in day 2) in the wild-type excluded population. The HRV load positively correlated with the symptom scores on days 2 and 5 (correlation coefficient 0.61 [p GG when compared to placebo. HRV load positively correlated with the total symptom scores. © 2016 ARS-AAOA, LLC.

  20. Respiratory and neurological disease in rabbits experimentally infected with equid herpesvirus 1.

    Science.gov (United States)

    Kanitz, Fábio A; Cargnelutti, Juliana F; Anziliero, Deniz; Gonçalves, Kelley V; Masuda, Eduardo K; Weiblen, Rudi; Flores, Eduardo F

    2015-10-01

    Equid herpesvirus type 1 (EHV-1) is an important pathogen of horses worldwide, associated with respiratory, reproductive and/or neurological disease. A mouse model for EHV-1 infection has been established but fails to reproduce some important aspects of the viral pathogenesis. Then, we investigated the susceptibility of rabbits to EHV-1 aiming at proposing this species as an alternative model for EHV-1 infection. Weanling rabbits inoculated intranasal with EHV-1 Kentucky D (10(7) TCID50/animal) shed virus in nasal secretions up to day 8-10 post-inoculation (pi), presented viremia up to day 14 pi and seroconverted to EHV-1 (virus neutralizing titers 4 to 64). Most rabbits (75%) developed respiratory disease, characterized by serous to hemorrhagic nasal discharge and mild to severe dyspnea. Some animals (20%) presented neurological signs as circling, bruxism and opisthotonus. Six animals died during acute disease (days 3-6); infectious virus and/or viral DNA were detected in the lungs, trigeminal ganglia (TG), olfactory bulbs (OBs) and cerebral cortex/brain (CC). Histological examination showed necrohemorrhagic, multifocal to coalescent bronchointerstitial pneumonia and diffuse alveolar edema. In two rabbits euthanized at day 50 pi, latent EHV-1 DNA was detected in the OBs. Dexamethasone administration at day 50 pi resulted in virus reactivation, demonstrated by virus shedding, viremia, clinical signs, and increase in VN titers and/or by detection of virus DNA in lungs, OBs, TGs and/or CC. These results demonstrate that rabbits are susceptible to EHV-1 infection and develop respiratory and neurological signs upon experimental inoculation. Thus, rabbits may be used to study selected aspects of EHV-1 biology and pathogenesis, extending and complementing the mouse model. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Experimental infection of Balb/c nude mice with Hepatitis E virus

    Directory of Open Access Journals (Sweden)

    Zhu Jianguo

    2009-06-01

    Full Text Available Abstract Background Several animal species can reportedly act as reservoirs for Hepatitis E virus (HEV, a zoonotic pathogen. HEV and antibody to the virus have been detected in a variety of animals including rodents. Pig and rat models for HEV have been established for HEV, but a nude mouse has not yet been developed. Methods Balb/c nude mice were inoculated with swine HEV, both orally and via intravenous injection to insure infection. Negative control and experimental contact-exposed groups of mice were also included in the study. The liver, spleen, kidney, jejunum, ileum, cecum and colon of each mouse from all three groups were collected for reverse transcription nested polymerase chain reaction (RT-nPCR detection, indirect immunofluorescence observation and histopathologic examination. The sera from nude mice were tested for anti-HEV IgG by enzyme linked immunosorbent assay (ELISA. Activities of liver enzymes, including alanine aminotransferase (ALT, aspartate aminotransferase (AST and alkaline phosphatase (ALP, as well as total bilirubin (TBIL were also measured in the sera of the nude mice. Results HEV antigens and HEV RNA were detected in liver, spleen, kidney, jejunum, ileum and colon both by indirect immunofluorescence and by RT-nPCR in all of the inoculated and in one of the contact-exposed nude mice. Histopathological changes were observed in the liver and spleen of these mice. Infected mice showed increased levels of AST, ALP, and anti-HEV IgG in sera. The livers of contact-exposed mice showed obvious histopathological damage. Conclusion Nude mice could be readily infected by HEV isolated from pigs. The nude mouse may therefore be a useful animal model for studying the pathogenesis of HEV.

  2. The efficacy of antihelminthic compound; Clorsulon against experimental Schistosoma mansoni infection.

    Science.gov (United States)

    Mossallam, Shereen F; Ali, Safia M; El Zawawy, Lobna A; Said, Doaa E

    2007-04-01

    The efficacy of Clorsulon (CLS) against experimental schistosomiasis mansoni, using Praziquantel (PZQ) as a therapeutic control was evaluated. Swiss Albino mice were divided into infected non-treated control, PZQ-treated group given a single dose of 500 mg/kg four weeks post infection (PI), and infected mice treated with single, double, and triple doses of 5 mg/kg CLS per dose, one week apart starting from the 4th week PI. All animals were perfused for adults count. Parts of livers and intestines were examined for granulomata number and sizes. Pathological changes in hepatic parenchyma by H&E and Masson trichrome stains were also examined. Results revealed that a single treatment with PZQ caused a significant percentage reduction (%R) of worm load (92.68%), mean egg count in liver and intestine (91.20 & 94.01% respectively), and mean size of liver granulomata was reduced (92.06%). Regarding CLS, the worm burden was reduced proportionally with number of doses given; 87.80, 96.34 & 97.56% in single, double and triple exposures successively. Egg count in liver was decreased by 85.90, 97.01 & 96.23% respectively in treated mice. Number of intestinal granulomata was decreased by 85.28, 94.24 & 95.49% in a similar way. Size of hepatic granulomata was decreased by 89.02, 94.51 & 95.05% by 1, 2 & 3 doses consecutively. All parameters reflected non significant difference between 2 & 3 dose of CLS. The results were critically discussed.

  3. Plant essential oils against Aeromonas hydrophila: in vitro activity and their use in experimentally infected fish.

    Science.gov (United States)

    Sutili, F J; Silva, L de Lima; Gressler, L T; Gressler, L T; Battisti, E K; Heinzmann, B M; de Vargas, A C; Baldisserotto, B

    2015-07-01

    The aims of this study were to investigate the in vitro antibacterial activity of the essential oils (EOs) of Hesperozygis ringens (HREO), popularly known as 'espanta-pulga' and two different species of basil, Ocimum gratissimum (OGEO) and Ocimum americanum (OAEO), as well as, the potential of these products to be used in silver catfish (Rhamdia quelen) infected with Aeromonas hydrophila. OGEO and HREO showed better antibacterial activity in vitro. Subinhibitory concentrations of all EOs inhibited haemolysis caused by Aer. hydrophila in fish erythrocytes (100% reduction for OAEO at 100 μg ml(-1) and more than 90% for HREO and OGEO at 150 μg ml(-1) ). However, OAEO and HREO showed the best survival results (75 and 70% respectively) after their use as treatment (therapeutic baths-1 h daily/5 days) in silver catfish experimentally infected with Aer. hydrophila. A second in vivo assay using healthy fish was conducted to verify the potential of the EOs (preventive baths-1 h daily/5 days) to promote fish survival. Fish exposed to HREO and OAEO and their diluent (ethanol) showed significant lower haematocrit values and higher complement system activity compared to control. Plasma cortisol level was significantly higher in the groups exposed to both EOs. There was no significant difference in survival of silver catfish challenged with Aer. hydrophila after preventive baths with HREO, OAEO and control group. All tested EOs showed in vitro antibacterial properties against Aer. hydrophila and HREO and OAEO showed potential to be used in the treatment of infected fish. These products can be used in aquaculture as therapeutic and prophylactic agents against fish pathogens, with antimicrobial and/or immunostimulant properties. © 2015 The Society for Applied Microbiology.

  4. An explorative study to assess the efficacy of Toltrazuril-sulfone (Ponazuril in calves experimentally infected with Neospora caninum

    Directory of Open Access Journals (Sweden)

    Greif Gisela

    2002-10-01

    Full Text Available Abstract Background Neospora caninum is an important cause of infectious abortion and stillbirth in cattle world-wide. Infection is common and may frequently be passed from mother to calf (vertical transmission with no signs of disease. Based on our previous observation that N. caninum-infection can be efficiently controlled with Toltrazuril-sulfone (Ponazuril in experimentally infected mice, we addressed the question if efficacy could also be obtained in experimentally infected calves. Material and Methods The study included 19 calves and represents an initial explorative approach to document a basic effectiveness at first. Fifteen animals received each 2 x 108N. caninum trophozoites, half of the dose being injected intravenously and the other half subcutaneously. Efficacy of treatment was assessed using molecular detection of parasite DNA with PCR and pathological alterations by immunohistochemistry in different organs of the animals. Assessment included also clinical, serological and pathophysiological parameters. Results In those calves medicated with ponazuril (one, or six consecutive days, respectively, starting one day after infection, a complete abrogation of the parasite detectability was obtained in the brain and other organs, while 50% of non-treated calves became PCR-positive in brain and muscles. Clinically, ponazuril chemotherapy of infected calves – in comparison to non-treated infected animals – reduced symptoms (fever, but no differences were observed between treated and non-treated animals with regard to serum enzymes and metabolites. Efficacy of a six-day treament was also reflected by significantly lower anti-Neospora antibody concentrations developed after infection, when compared to non-treated animals. Conclusion Based on our findings in this initially explorative approach that indicate a basic effectiveness of ponazuril against experimental N. caninum infection in calves, we plan to follow our chemotherapeutical

  5. An explorative study to assess the efficacy of toltrazuril-sulfone (ponazuril) in calves experimentally infected with Neospora caninum.

    Science.gov (United States)

    Kritzner, Sandra; Sager, Heinz; Blum, Jürg; Krebber, Ralph; Greif, Gisela; Gottstein, Bruno

    2002-10-18

    Neospora caninum is an important cause of infectious abortion and stillbirth in cattle world-wide. Infection is common and may frequently be passed from mother to calf (vertical transmission) with no signs of disease. Based on our previous observation that N. caninum-infection can be efficiently controlled with toltrazuril-sulfone (ponazuril) in experimentally infected mice, we addressed the question if efficacy could also be obtained in experimentally infected calves. The study included 19 calves and represents an initial explorative approach to document a basic effectiveness at first. Fifteen animals received each 2 x 10(8) N. caninum trophozoites, half of the dose being injected intravenously and the other half subcutaneously. Efficacy of treatment was assessed using molecular detection of parasite DNA with PCR and pathological alterations by immunohistochemistry in different organs of the animals. Assessment included also clinical, serological and pathophysiological parameters. In those calves medicated with ponazuril (one, or six consecutive days, respectively, starting one day after infection), a complete abrogation of the parasite detectability was obtained in the brain and other organs, while 50% of non-treated calves became PCR-positive in brain and muscles. Clinically, ponazuril chemotherapy of infected calves--in comparison to non-treated infected animals--reduced symptoms (fever), but no differences were observed between treated and non-treated animals with regard to serum enzymes and metabolites. Efficacy of a six-day treatment was also reflected by significantly lower anti-Neospora antibody concentrations developed after infection, when compared to non-treated animals. Based on our findings in this initially explorative approach that indicate a basic effectiveness of ponazuril against experimental N. caninum infection in calves, we plan to follow our chemotherapeutical intervention strategy to control bovine neosporosis with a subsequent more

  6. Gastrointestinal trichostrongylosis can predispose ewes to clinical mastitis after experimental mammary infection.

    Science.gov (United States)

    Mavrogianni, V S; Papadopoulos, E; Gougoulis, D A; Gallidis, E; Ptochos, S; Fragkou, I A; Orfanou, D C; Fthenakis, G C

    2017-10-15

    Objective was to study, in an experimental model, the possible role of gastrointestinal nematode infection in predisposing ewes to mastitis during the lactation period. Twenty-four ewes (A or B [n=12]), free from nematode and trematode helminths, were used. Group A animals received 5000 third-stage larvae of a trichostrongylid helminth cocktail and group B ewes were unparasitised controls. Animals in group A developed gastrointestinal trichostrongylosis confirmed by >500epg in faecal samples; mean epg of group B ewes were mastitis; no ewe in group B developed clinical mastitis, but only subclinical (12 ewes) (P=0.002). M. haemolytica was isolated from 132/132 and 121/132 udder samples from group A or B, respectively (Pmastitis than in others which did not (0.709 and 0.162 versus 0.662 and 0.136, respectively; Pmastitis (in group A or B), inducible-lymphoid-follicles were observed in the teat, which were not observed in ewes with clinical disease. Total pathology scores summed over all days were 127 and 73 for group A or B ewes, respectively (maximum possible 192; Pmastitis. It is concluded that, in view of bacterial challenge, gastrointestinal trichostrongylosis and particularly Teladorsagia infection, might lead to clinical mastitis, through various pathogenetic pathways. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. An experimental Helicobacter suis infection causes gastritis and reduced daily weight gain in pigs.

    Science.gov (United States)

    De Bruyne, Ellen; Flahou, Bram; Chiers, Koen; Meyns, Tom; Kumar, Smitha; Vermoote, Miet; Pasmans, Frank; Millet, Sam; Dewulf, Jeroen; Haesebrouck, Freddy; Ducatelle, Richard

    2012-12-07

    Helicobacter suis is a zoonotically important bacterium, that has been associated with gastritis and ulcerative lesions of the pars oesophagea of the stomach in pigs. Its exact role in these pathologies, however, still remains controversial. Therefore, a total of 29 medicated early weaned piglets were inoculated intragastrically or orally, with a total of 2 × 10(9) viable H. suis bacteria and the effect on gastric pathology and weight gain was determined. Twenty-three medicated early weaned piglets were inoculated with a sterile culture medium and used as sham-inoculated controls. The animals were euthanized between 28 and 42 days after inoculation. Infected animals showed a more severe gastritis compared to the control group. There was also a significant reduction of approximately 60 g per day (10%) in weight gain in H. suis inoculated animals compared to the sham-inoculated control animals. In conclusion, this study demonstrates for the first time that a pure in vitro culture of H. suis not only causes gastritis but also a marked decrease of the daily weight gain in experimentally infected pigs. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Experimental Oral Herpes Simplex Virus-1 (HSV-1 Co-infection in Simian Immunodeficiency Virus (SIV-Infected Rhesus Macaques

    Directory of Open Access Journals (Sweden)

    Meropi Aravantinou

    2017-12-01

    Full Text Available Herpes simplex virus 1 and 2 (HSV-1/2 similarly initiate infection in mucosal epithelia and establish lifelong neuronal latency. Anogenital HSV-2 infection augments the risk for sexual human immunodeficiency virus (HIV transmission and is associated with higher HIV viral loads. However, whether oral HSV-1 infection contributes to oral HIV susceptibility, viremia, or oral complications of HIV infection is unknown. Appropriate non-human primate (NHP models would facilitate this investigation, yet there are no published studies of HSV-1/SIV co-infection in NHPs. Thus, we performed a pilot study for an oral HSV-1 infection model in SIV-infected rhesus macaques to describe the feasibility of the modeling and resultant immunological changes. Three SIV-infected, clinically healthy macaques became HSV-1-infected by inoculation with 4 × 108 pfu HSV-1 McKrae on buccal, tongue, gingiva, and tonsils after gentle abrasion. HSV-1 DNA was shed in oral swabs for up to 21 days, and shedding recurred in association with intra-oral lesions after periods of no shedding during 56 days of follow up. HSV-1 DNA was detected in explant cultures of trigeminal ganglia collected at euthanasia on day 56. In the macaque with lowest baseline SIV viremia, SIV plasma RNA increased following HSV-1 infection. One macaque exhibited an acute pro-inflammatory response, and all three animals experienced T cell activation and mobilization in blood. However, T cell and antibody responses to HSV-1 were low and atypical. Through rigorous assessesments, this study finds that the virulent HSV-1 strain McKrae resulted in a low level HSV-1 infection that elicited modest immune responses and transiently modulated SIV infection.

  9. Laboratory experimental infection of sheep to Ornithobilharzia turkestanicum and its confirmation using post-mortem examination and histopathology

    Directory of Open Access Journals (Sweden)

    gholamreza karimi

    2014-11-01

    Full Text Available Ornithobilharzia turkestanicum from genus Ornithobilharzia genus and family Schistosomatidae is an important agent of parasitological infection in sheep. This parasite has been reported from Russia, China, Turkestan (Kazakhstan, Kyrgyzstan, Turkmenistan and Uzbekistan, Pakistan, Iraq, Turkey and Iran. Parasitological infection due to this agent could be one of the important factors of decreasing the production rate of livestock in Iran. The purpose of this study, was to experimentally infect sheep with this parasite and confirm the infection by post-mortem examination and Histopathology which was done successfully. Twenty five sheep were used in the study of which 10 sheep were experimentally infected by Ornithobilharzia turkestanikum using subcutaneous injection and 10 sheep by skin contact method and the other 5 sheep were kept as control. Result of post-mortem and Histopathology during a one year period confirmed that all of sheep were infected and adult worm, were seen in their mesentery. Mean number of cercaria used for inducing the infection was 6425 and 462 adult worms were collected post-mortem. There was no significant relationship between the number of cercaria and adult worms collected. Male sheep were more infected than female.

  10. Major histocompatibility complex-controlled protective influences on experimental autoimmune encephalomyelitis are peptide specific

    DEFF Research Database (Denmark)

    Issazadeh-Navikas, Shohreh; Kjellén, P; Olsson, T

    1997-01-01

    The myelin basic protein (MBP) peptide 63-88-induced experimental autoimmune encephalomyelitis (EAE) and its associated T cell cytokine profile are influenced by the rat major histocompatibility complex (MHC). There is an allele-specific protective influence of the MHC class I region, whereas...... the MHC class II region display either disease-protective or -promoting effects. To investigate if the MHC-associated protection is dependent on certain combinations of MBP peptide and MHC molecules, we have now used another peptide (MBP 89-101). A broader and different set of rat MHC alleles were......-101 peptide, except in LEW.1N (RT1 pi) rats which were relatively resistant. Only this strain responded with additional Th2-like and transforming growth factor-beta responses to the peptide in vitro. In vivo depletion of CD8+ cells aggravated the disease in this strain. We conclude that both MHC...

  11. Experimental thermal conductivity, thermal diffusivity, and specific heat values for mixtures of nitrogen, oxygen, and argon

    Science.gov (United States)

    Perkins, R. A.; Cieszkiewicz, M. T.

    1991-01-01

    Experimental measurements of thermal conductivity and thermal diffusivity obtained with a transient hot-wire apparatus are reported for three mixtures of nitrogen, oxygen, and argon. Values of the specific heat, Cp, are calculated from these measured values and the density calculated with an equation of state. The measurements were made at temperatures between 65 and 303 K with pressures between 0.1 and 70 MPa. The data cover the vapor, liquid, and supercritical gas phases for the three mixtures. The total reported points are 1066 for the air mixture (78.11 percent nitrogen, 20.97 percent oxygen, and 0.92 percent argon), 1058 for the 50 percent nitrogen, 50 percent oxygen mixture, and 864 for the 25 percent nitrogen, 75 oxygen mixture. Empirical thermal conductivity correlations are provided for the three mixtures.

  12. Rituximab therapy reduces organ-specific T cell responses and ameliorates experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Monson, Nancy L; Cravens, Petra; Hussain, Rehana; Harp, Christopher T; Cummings, Matthew; de Pilar Martin, Maria; Ben, Li-Hong; Do, Julie; Lyons, Jeri-Anne; Lovette-Racke, Amy; Cross, Anne H; Racke, Michael K; Stüve, Olaf; Shlomchik, Mark; Eagar, Todd N

    2011-02-16

    Recent clinical trials have established B cell depletion by the anti-CD20 chimeric antibody Rituximab as a beneficial therapy for patients with relapsing-remitting multiple sclerosis (MS). The impact of Rituximab on T cell responses remains largely unexplored. In the experimental autoimmune encephalomyelitis (EAE) model of MS in mice that express human CD20, Rituximab administration rapidly depleted peripheral B cells and strongly reduced EAE severity. B cell depletion was also associated with diminished Delayed Type Hypersensitivity (DTH) and a reduction in T cell proliferation and IL-17 production during recall immune response experiments. While Rituximab is not considered a broad immunosuppressant, our results indicate a role for B cells as a therapeutic cellular target in regulating encephalitogenic T cell responses in specific tissues.

  13. Rituximab therapy reduces organ-specific T cell responses and ameliorates experimental autoimmune encephalomyelitis.

    Directory of Open Access Journals (Sweden)

    Nancy L Monson

    Full Text Available Recent clinical trials have established B cell depletion by the anti-CD20 chimeric antibody Rituximab as a beneficial therapy for patients with relapsing-remitting multiple sclerosis (MS. The impact of Rituximab on T cell responses remains largely unexplored. In the experimental autoimmune encephalomyelitis (EAE model of MS in mice that express human CD20, Rituximab administration rapidly depleted peripheral B cells and strongly reduced EAE severity. B cell depletion was also associated with diminished Delayed Type Hypersensitivity (DTH and a reduction in T cell proliferation and IL-17 production during recall immune response experiments. While Rituximab is not considered a broad immunosuppressant, our results indicate a role for B cells as a therapeutic cellular target in regulating encephalitogenic T cell responses in specific tissues.

  14. Epitope-Specific Tolerance Modes Differentially Specify Susceptibility to Proteolipid Protein-Induced Experimental Autoimmune Encephalomyelitis

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2017-11-01

    Full Text Available Immunization with myelin components can elicit experimental autoimmune encephalomyelitis (EAE. EAE susceptibility varies between mouse strains, depending on the antigen employed. BL/6 mice are largely resistant to EAE induction with proteolipid protein (PLP, probably a reflection of antigen-specific tolerance. However, the extent and mechanism(s of tolerance to PLP remain unclear. Here, we identified three PLP epitopes in PLP-deficient BL/6 mice. PLP-sufficient mice did not respond against two of these, whereas tolerance was “leaky” for an epitope with weak predicted MHCII binding, and only this epitope was encephalitogenic. In TCR transgenic mice, the “EAE-susceptibility-associated” epitope was “ignored” by specific CD4 T cells, whereas the “resistance-associated” epitope induced clonal deletion and Treg induction in the thymus. Central tolerance was autoimmune regulator dependent and required expression and presentation of PLP by thymic epithelial cells (TECs. TEC-specific ablation of PLP revealed that peripheral tolerance, mediated by dendritic cells through recessive tolerance mechanisms (deletion and anergy, could largely compensate for a lack of central tolerance. However, adoptive EAE was exacerbated in mice lacking PLP in TECs, pointing toward a non-redundant role of the thymus in dominant tolerance to PLP. Our findings reveal multiple layers of tolerance to a central nervous system autoantigen that vary among epitopes and thereby specify disease susceptibility. Understanding how different modalities of tolerance apply to distinct T cell epitopes of a target in autoimmunity has implications for antigen-specific strategies to therapeutically interfere with unwanted immune reactions against self.

  15. SPECIFIC AGGLUTINATION OF TREPONEMA PALLIDUM BY SERA FROM RABBITS AND HUMAN BEINGS WITH TREPONEMAL INFECTIONS

    Science.gov (United States)

    Hardy, Paul H.; Nell, E. Ellen

    1955-01-01

    A method has been described for the preparation of Treponema pallidum suspensions that are suitable for specific agglutination studies and can be stored at 4°C. for months without loss of agglutinability. Such suspensions have been shown to react with two distinct antibodies in the serum of syphilitic animals and man: Wassermann antibody and a specific treponeme agglutinin. It has been demonstrated that the agglutination of treponemes by specific treponeme agglutinin is enhanced by heat treatment or aging of the suspension, and inhibited by a divalent cation, probably Ca++, normally present in serum. This inhibition has been overcome by the use of a chelating agent, ethylene-diamine tetracetate. These findings have been utilized to devise a simple agglutination test for the diagnosis of treponeme infections that is very sensitive and highly specific. This test has been carried out with 430 human sera, and a comparison has been made of the results of the agglutination, treponemal immobilization, and standard serological tests on these sera. The agglutination test appears to have a specificity comparable to the treponemal immobilization test and considerably greater than the standard serological tests. PMID:14354107

  16. Attributing the Human Disease Burden of Foodborne Infections to Specific Sources

    DEFF Research Database (Denmark)

    Pires, Sara Monteiro; Evers, Eric E.; Van Pely, Wilfrid

    2009-01-01

    Foodborne diseases are an important cause of human illness worldwide. Humans acquire these infections from a variety of sources and routes of transmission. Many efforts have been made in the last decades to prevent and control foodborne diseases, particularly foodborne zoonoses. However......, information on the impact of these interventions is limited. To identify and prioritize successful food safety interventions, it is important to attribute the burden of human illness to the specific sources. Defining scientific concepts and harmonizing terminology for ‘‘source attribution’’ is essential...... for understanding and improving attribution methodologies and for sharing knowledge within the scientific community. We propose harmonized nomenclature, and describe the various approaches for human illness source attribution and their usefulness to address specific public health questions....

  17. Lipid and glucose metabolism of broilers (Gallus gallus domesticus experimentally infected with Eimeria acervulina Tyzzer, 1929 oocysts

    Directory of Open Access Journals (Sweden)

    FLC Freitas

    2008-09-01

    Full Text Available Lipid and glucose metabolism of 76 ten-day-old Cobb male broilers, experimentally infected with Eimeria acervulina, was studied for 30 days. Birds were distributed in 2 groups: one infected with 1x10(6 E. acervulina sporulated oocysts, and the other inoculated with distilled water. Pathological e biochemical liver changes were assessed, as well as plasma glucose concentrations and total cholesterol, HDL, LDL, VLDL, fatty-acid, and triglyceride levels in the serum. The infected broilers presented hypoglycemia associated with a reduction in liver glycogen. In addition, these birds developed fatty liver, and there were changes in all lipid classes in the serum. Lipid and glucose metabolism was dramatically changed in broilers experimentally infected with 1x10(6 E. acervulina oocysts.

  18. Acute phase response in two consecutive experimentally induced E. coli intramammary infections in dairy cows

    Directory of Open Access Journals (Sweden)

    Saatsi Johanna

    2008-06-01

    Full Text Available Abstract Background Acute phase proteins haptoglobin (Hp, serum amyloid A (SAA and lipopolysaccharide binding protein (LBP have suggested to be suitable inflammatory markers for bovine mastitis. The aim of the study was to investigate acute phase markers along with clinical parameters in two consecutive intramammary challenges with Escherichia coli and to evaluate the possible carry-over effect when same animals are used in an experimental model. Methods Mastitis was induced with a dose of 1500 cfu of E. coli in one quarter of six cows and inoculation repeated in another quarter after an interval of 14 days. Concentrations of acute phase proteins haptoglobin (Hp, serum amyloid A (SAA and lipopolysaccharide binding protein (LBP were determined in serum and milk. Results In both challenges all cows became infected and developed clinical mastitis within 12 hours of inoculation. Clinical disease and acute phase response was generally milder in the second challenge. Concentrations of SAA in milk started to increase 12 hours after inoculation and peaked at 60 hours after the first challenge and at 44 hours after the second challenge. Concentrations of SAA in serum increased more slowly and peaked at the same times as in milk; concentrations in serum were about one third of those in milk. Hp started to increase in milk similarly and peaked at 36–44 hours. In serum, the concentration of Hp peaked at 60–68 hours and was twice as high as in milk. LBP concentrations in milk and serum started to increase after 12 hours and peaked at 36 hours, being higher in milk. The concentrations of acute phase proteins in serum and milk in the E. coli infection model were much higher than those recorded in experiments using Gram-positive pathogens, indicating the severe inflammation induced by E. coli. Conclusion Acute phase proteins would be useful parameters as mastitis indicators and to assess the severity of mastitis. If repeated experimental intramammary

  19. Time course of gene expression profiling in the liver of experimental mice infected with Echinococcus multilocularis.

    Directory of Open Access Journals (Sweden)

    Renyong Lin

    Full Text Available BACKGROUND: Alveolar echinococcosis (AE is a severe chronic parasitic disease which behaves like a slow-growing liver cancer. Clinical observations suggest that the parasite, Echinococcus multilocularis (E. multilocularis influences liver homeostasis and hepatic cell metabolism. However, this has never been analyzed during the time course of infection in the common model of secondary echinococcosis in experimental mice. METHODOLOGY/PRINCIPAL FINDINGS: Gene expression profiles were assessed using DNA microarray analysis, 1, 2, 3 and 6 months after injection of E. multilocularis metacestode in the liver of susceptible mice. Data were collected at different time points to monitor the dynamic behavior of gene expression. 557 differentially expressed genes were identified at one or more time points, including 351 up-regulated and 228 down-regulated genes. Time-course analysis indicated, at the initial stage of E. multilocularis infection (month 1-2, that most of up-regulated pathways were related to immune processes and cell trafficking such as chemokine-, mitogen-activated protein kinase (MAPK signaling, and down-regulated pathways were related to xenobiotic metabolism; at the middle stage (month 3, MAPK signaling pathway was maintained and peroxisome proliferator-activated receptor (PPAR signaling pathway emerged; at the late stage (month 6, most of up-regulated pathways were related to PPAR signaling pathway, complement and coagulation cascades, while down-regulated pathways were related to metabolism of xenobiotics by cytochrome P450. Quantitative RT-PCR analysis of a random selection of 19 genes confirmed the reliability of the microarray data. Immunohistochemistry analysis showed that proliferating cell nuclear antigen (PCNA was increased in the liver of E. multilocularis infected mice from 2 months to 6 months. CONCLUSIONS: E. multilocularis metacestode definitely exerts a deep influence on liver homeostasis, by modifying a number of gene

  20. Seasonality and circadian variation of microfilaremia in dogs experimentally infected with Dirofilaria immitis.

    Science.gov (United States)

    Lovis, Léonore; Grandjean, Mélanie; Overney, Laurence; Seewald, Wolfgang; Sager, Heinz

    2017-08-30

    Periodicity, the cyclical rise and fall in microfilaria (mff) numbers in the peripheral blood over time, is observed in many filarial infections. It is correlated with the necessity for these larval stages to be ingested by the blood feeding vector before they can be transmitted to a new vertebrate host. Microfilariae of the dog heartworm Dirofilaria immitis have been described to show periodicity, but the circadian pattern does not seem to be consistent. Most publications describe the lowest mff-concentrations in the peripheral blood in the early morning, while the highest counts occurred either in the afternoon, in the late evening or shortly after midnight. Sixteen dogs were experimentally infected with D. immitis isolates originating from Italy (one isolate, 14 dogs), and the USA (two isolates, one dog each). The dogs were housed indoors with a natural light source (windows) and heating that prevented temperature-drops below 20°C during winter. When patency was reached, blood samples were collected at weekly and monthly intervals over a period of up to 3 years, and at given hours of the day (morning, noon, evening) for the duration of one year in order to determine seasonal, as well as daily variations of microfilaremia. Despite the fact that the dogs were kept indoors, there was an apparent seasonality of the D. immitis-microfilaremia, with peaks in summer and 5-49-times lower counts in winter. This difference was statistically significant and the ratio remained constant over the years, regardless of the fact that the mff-counts increased from the first to the second year of patency. Since the temperature was kept constantly in a range between 20 to 26°C (with some single outliners in both directions) the climatic conditions may not explain this observation. Therefore, day length may be the most obvious reason for the seasonality in the given study set-up. Interestingly, the Italian D. immitis-isolate lost seasonality after three passages of experimental

  1. Reversibility of cardiac fibrosis in mice chronically infected with Trypanosoma cruzi, under specific chemotherapy

    Directory of Open Access Journals (Sweden)

    Sonia G. Andrade

    1991-06-01

    Full Text Available This investigation was performed to verify the effect of specific chemotherapy (Benznidazole or MK-346 on the inflammatory and fibrotic cardiac alterations in mice chronically infected with the strains 21 SF (Type II and Colombian (Type III of Trypanosoma cruzi. To obtain chronically infected mice, two groups of 100 Swiss mice each, were infected with either the 21 SF or the Colombian strain (2x 10 [raised to the power of] 4 and 5x 10 [raised to the power of] 4 blood forms respectively. The rate of morality in the acute phase was of 80% for both groups. Twenty surviving mice chronically infected with the 21 SF strain and 20 with the Colombian strain were then divided in treated and untreated groups. Excluding those that died during the course of treatment, 14 mice chronically infected with the 21 SF strain and 15 with the Colombian strain were evaluated in the present study. Chemotherapy was performed with Benznidazole (N-benzil-2-nitro-1-imidazolacetamide in the dose of 100mg/k.b.w/day, for 60 days, or with the MK-436(3(1-methyl-5 nitroimidazol-2-yl in two daily doses of 250 mg/k.b.w, for 20 days. Parasitological cure tests were performed (xenodiagnosis, haemoculture, subinovulation of the blood into newborn mice, and serological indirect immunofluorescence test. The treated and untreated mice as well as intact controls were killed at different periods after treatment and the heart were submitted to histopathological study with hematoxilineosin and picrosirius staining; ultrastructural study; collagen immunotyping, fibronectin and laminin identification by immunofluorescence tests. Results: the untreated controls either infected with 21 SF or Colombian strain, showed inflammatory and fibrotic alterations that were mild to moderate with the 21 SF strain and intense with the Colombian strain. Redpicrosirius staining showed bundles of collagen in the interstitial space and around cardiac fibers. Increased deposits of mitritial components and

  2. Infecções experimentaes na Leishmaniose visceral americana Experimental infections in american visceral leishmaniasis

    Directory of Open Access Journals (Sweden)

    Aristides Marques da Cunha

    1938-01-01

    sôro-agglutinação, conforme mostramos em trabalho anterior, não permite a separação das especies do genero Leishmania, pois todas ellas, quando recentemente isoladas, possuem identica constituição antigenica, que se modifica depois, pela conservação longo tempo em cultura. É esse facto, que deu logar ás conclusões contradictorias a que chegaram os autores que se ocuparam do assumpto bem como os primeiros resultados que obtivemos. Deante de todos esses factos, nos julgamos autorizados a concluir como já fizemos anteriormente, que o agente da Leishmaniose visceral americana é identico á Leishmania infantum. Ao terminar, queremos deixar consignados nossos agradecimentos ao Dr. E. chagas, por ter posto a nossa disposição as culturas de Leishmania por elle isoladas, tornando possivel deste modo, a execução do presente trabalho.With cultures isolated from cases of american visceral leishmaniasis we succeeded in obtaining experimental infections in hamsters (Cricetus cricetus, rhesus monkeys (Macaca mullata and dogs. Hamsters were infected with strains obtained from man and dogs, the intraperitoneal way having been always employed. When cultures recently isolated are used, infection is obtained practically in 100% of the animals inoculated. The first negative results obtained by us may be explained by the use of cultures isolated some time before (about 7 months 0 and which had lost already their virulence. In some cases external lesions are observed represented by alterations of the skin and swelling of the paws. The skin lesions are observed on the ventral surface and consist in depilation, erythema and exudation. The skin thus affected shows to be extremely friable, rupturing at the movements of the animal when hold. On post-mortem examination, besides the lesions pointed out, the animals present enlargement of the spleen. The parasites are very numerous in the spleen, liver, bone marrow, etc. The changed skin shows considerable hypertrophy of the

  3. Cell-specific type I IFN signatures in autoimmunity and viral infection: what makes the difference?

    Directory of Open Access Journals (Sweden)