Veterinary parasitology teaching in eastern Australia

There are tendencies in universities globally to change undergraduate teaching in veterinary parasitology. To be able to give considered advice to universities, faculties, governmental bodies and professional societies about a discipline and to establish how particular changes may impact on the quality of a course, is the requirement to record and review its current status. The present paper contributes toward this objective by providing a snap-shot of the veterinary parasitology courses at the Universities of Melbourne, Sydney and Queensland in eastern Australia. It includes a description of the veterinary science curriculum in each institution, and provides an outline of its veterinary parasitology course, including objectives, topics covered, course delivery, student examination procedures and course evaluation. Student contact time in veterinary parasitology during the curriculum is currently higher in Melbourne (183 h) compared with Sydney and Queensland (106-110 h). In the teaching of parasitology, Melbourne adopts a taxonomic approach (in the pre-clinical period) followed by a combined disciplinary and problem-based approach in the clinical semesters, whereas both Sydney and Queensland focus more on presenting parasites on a host species-basis followed by a problem-based approach. (C) 2002 Elsevier Science B.V. All rights reserved.

Nanotechnology: meeting the future of Veterinary Parasitology Research

Abstract: The field of nanotechnology involves an array of different areas of expertize with the application of innovative products in Medicine, Engineering, and to a less extent to Veterinary Medicine. In our opinion, more research is needed, in special to Animal Parasitology, to develop state of the art products to solve old problems. Livestock, pets and wildlife may benefit from products in nanoscale, such as vaccines, target recombinant proteins, or new drug candidates. Thus, we want to give some food for thought to drive scientific programs into nanotechnology, creating a safer environment to animals and humans

World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines for evaluating the efficacy of acaricides against ticks (Ixodidae) on ruminants

These guidelines have been prepared to assist in the planning, conduct and interpretation of studies for the assessment of the efficacy of acaricides (excluding vaccines and other bio-control agents) against single and multi-host ticks (Ixodidae) on ruminants. Information is provided on the selection of animals, dose determination, dose confirmation and field studies, record keeping and result interpretation. The use of pen facilities is advocated for dose determination and confirmation studies for defining therapeutic and persistent efficacy. A minimum of two studies per tick species for which claims are sought is recommended for each dose determination and dose confirmation investigation. If dose confirmation studies demonstrate greater than 95% efficacy the sponsor may proceed to field studies, where a minimum of two studies per geographical location is preferred to confirm the therapeutic and persistent efficacy under field conditions. If dose confirmation studies demonstrate less than 95% efficacy then longer-term field studies can be conducted over two tick seasons with a minimum of two studies per geographical location. These studies can incorporate other control methods such as tick vaccines, to demonstrate stable long-term tick management. Specific advice is also given on conducting studies with paralysis ticks. These guidelines are also intended to assist investigators on how to conduct specific experiments, to provide specific information for registration authorities involved in the decision-making process, to assist in the approval and registration of new acaricides, and to facilitate the worldwide adoption of standard procedures. (c) 2005 Elsevier B.V. All rights reserved.

Ehrlichia canis in dogs attended in a veterinary hospital from Botucatu, Sao Paulo State, Brazil

This study investigated the etiology of canine ehrlichiosis and possible clinical and epidemiological data associated with the infection in 70 dogs suspect of ehrlichiosis attended at the Veterinary Hospital of the Sao Paulo State University in Botucatu city during 2001 and 2002. Dogs were evaluated by clinical-epidemiological and hematological data and molecular analysis by partial amplification and DNA sequencing of the ehrlichial dsb gene. E. canes DNA was amplified and sequenced in 28 (40.0%) dogs. Dogs younger than 12 months old showed significantly higher infection rates (65.0%; P < 0.05). Diarrhea, apathy, and anorexia were the major clinical signs observed in 55.2% (P = 0.05), 47.0% (P > 0.05), and 42.4% (P > 0.05) of the PCR-positive dogs, respectively. Twenty-five anemic (<5.5 x 10(6) RBC.mu L(-1)), and 8 leukopenic (<5.5 x 10(3) WBC.mu L(-1)) dogs were PCR-positive (P > 0.05). All 28 PCR-positive dogs showed thrombocytopenia (<175 x 10(3) platelets.mu L(-1)) and revealed statistical significance (P < 0.05). E. canis was the only Ehrlichia species found in dogs in the studied region, with higher infection rates in younger dogs, and statistically associated with thrombocytopenia.

Caenorhabditis elegans as a model to screen plant extracts and compounds as natural anthelmintics for veterinary use

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Detection of IgG antibodies to Neospora caninum and Toxoplasma gondii in dogs examined in a veterinary hospital from Brazil

A total of 163 dogs with neuromuscular, respiratory and/or gastrointestinal disorders, was admitted at the Veterinary Hospital, Federal University of Uberlandia, Brazil, and submitted to serology for Toxoplasma gondii and Neospora caninum. Assays for T gondii included indirect haemagglutination (IHA), indirect fluorescent antibody (IFAT-Tg), immunoenzymatic (ELISA), and immunoblotting (IB-Tg). Assays for N, caninum included IFAT-Nc and immunoprecipitation (IP-Nc). Based on concordant results by three serological tests (IHA, IFAT-Tg and ELISA) for T gondii, and divergent results further confirmed by IB-Tg for reactivity to TgSAG1, the 163 sera were divided into two groups: 59 (36%) Tg-seropositive samples and 104 (64%) Tg-seronegative samples. Antibodies to Neospora were detected in 11 (6.7%) out of 163 analyzed dog sera, with 5 (3.1 %) samples reactive to both parasites (Tg+/Nc+), and 6 (3.7%) reactive only to Neospora (Tg-/Nc+). Antibodies only to T: gondii were found in 54 (33%) samples. Among the 11 Neospora-positive sera analyzed by IB-Tg, the five sera Tg+/Nc+ showed strong reactivity to Toxoplasma antigens, especially to TgSAG1 (p30). No reactivity was observed to TgSAG1 in the six samples Tg-/Nc+. By TP-Nc, two highly immunodominant antigens (29 and 35 kDa proteins) were recognized by all 11 IFAT-Nc positive sera. Our results suggest that the infection by N, caninum can be concomitantly present in dogs from this area, although less common, and therefore should be considered in the differential clinical diagnosis with T. gondii in dogs presenting neuromuscular, respiratory and/or gastrointestinal disorders. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Application of Cognitive Engineering Principles to the Redesign of a Dichotomous Identification Key for Parasitology

Dichotomous identification keys are used throughout biology for identification of plants, insects, and parasites. However, correct use of identification keys can be difficult as they are not usually intended for novice users who may not be familiar with the terminology used or with the morphology of the organism being identified. Therefore, we applied cognitive engineering principles to redesign a parasitology identification key for the Internet. We addressed issues of visual clutter and spatial distance by displaying a single question couplet at a time and by switching to the appropriate next couplet after the user made a choice. Our analysis of the original paper-based key versus the Web-based approach found that of 26 applicable cognitive engineering principles, the paper key did not meet 4 (15%) and partially met 11 (42%). In contrast, the redesigned key met 100% of 32 applicable cognitive engineering principles.

An outline of lectures on animal parasitology : course 44, first term of third year /

Mode of access: Internet.

The finding of Lutzomyia almerioi and Lutzomyia longipalpis naturally infected by Leishmania spp. in a cutaneous and canine visceral leishmaniases focus in Serra da Bodoquena, Brazil

To identify natural infections by Leishmania spp. in insect vectors of cutaneous and visceral leishmaniasis, we performed field studies in natural and anthropic environments in the Guaicurus Settlement (Bodoquena Range) of the Bonito municipality, Mato Grosso do Sul state, Brazil. From October 2002 to October 2003, a total of 1395 sandfly females were captured with Shannon and light traps and dissected in search of flagellates. The sample is composed of a total of 13 species, with Lutzomyia almerioi (59.9%) and Lutzomyia longipalpis (31.4%) predominant. Infections by flagellates were directly observed in three of the dissected of Lu. almerioi females (0.36%). To increase the sensitivity of detection, DNA extracted from pools of the 1220 dissected females (Lu. almerioi 808, Lu. longipalpis 399 and Nyssomyia whitmani 13) was subjected to small subunit rRNA-based polymerase chain reactions (SSU-PCR). DNA from Leishmania (L.) infantum chagasi was detected in at least 0.37% of Lu. almerioi females and in 0.25% of Lu. longipalpis females. The DNA of the Leishmania (Viannia) sp. was detected in 0.12% of Lu. almerioi and in 0.70% of Lu. longipalpis. Leishmania (L.) amazonensis was found in 1.25% of Lu. longipalpis. Mixed infections of L. (Leishmania) sp. and L. (Viannia) sp. were found in 0.50% of Lu. longipalpis. When considering that each positive pool contained at least a single infected specimen, we found a 1.23% rate of Leishmania spp. infection among the total population of dissected female sand flies as determined by PCR. This is the first report of natural infection by L. (L.) infantum chagasi and L. (Viannia) sp. in Lu. almerioi. It is also the first report of infection by L. (Viannia) sp. in Lu. longipalpis. The observation that Lu. longipalpis and Lu. almerioi are naturally infected by agents of both cutaneous and visceral leishmaniases suggests that these two species play a role in the transmission (continua) (continuação) of these diseases within the study area. Furthermore, the finding that Lu. longipalpis has been naturally infected by L. (L.) amazonensis and L. (Viannia) sp., and Lu. almerioi by L. (L.) infantum chagasi and L. (Viannia), suggests their participation as permissive vectors

Tick saliva induces regulatory dendritic cells: MAP-kinases and Toll-like receptor-2 expression as potential targets

Ticks (Acari: Ixodidae) are bloodsucking ectoparasitic arthropods of human and veterinary medical importance. Tick saliva has been shown to contain a wide range of bioactive molecules with vasodilatory, antihemostatic, and immunomodulatory activities. We have previously demonstrated that saliva from Rhipicephalus sanguineus ticks inhibits the maturation of dendritic cells (DCs) stimulated with LPS. Here we examined the mechanism of this immune subversion, evaluating the effect of tick saliva on Toll-like receptor (TLR)-4 signalling pathway in bone marrow-derived DCs. We demonstrated that R. sanguineus tick saliva impairs maturation of DCs stimulated with LIPS, a TLR-4 ligand, leading to increased production of interleukin (IL)-10 and reduced synthesis of IL-12p70 and TNF-alpha. The immunomodulatory effect of the tick saliva on the production of pro-inflammatory cytokines by DCs stimulated with LPS was associated with the observation that tick saliva inhibits the activation of the ERK 1/2 and p38 MAP kinases. These effects were independent of the expression of TLR-4 on the surface of DCs. Additionally, saliva-treated DCs also presented a similar pattern of cytokine modulation in response to other TLR ligands. Since the recent literature reports that several parasites evade immune responses through TLR-2-mediated production of IL-10, we evaluated the effect of tick saliva on the percentage of TLR-2(+) DCs stimulated with the TLR-2 ligand lipoteicoic acid (LTA). The data showed that the population of DCs expressing TLR-2 was significantly increased in DCs treated with LTA plus saliva. In addition, tick saliva alone increased the expression of TLR-2 in a dose- and time-dependent manner. Our data suggest that tick saliva induces regulatory DCs, which secrete IL-10 and low levels of IL-12 and TNF-alpha when stimulated by TLR ligands. Such regulatory DCs are associated with expression of TLR-2 and inhibition of ERK and p38, which promotes the production of IL-10 and thus down-modulates the host`s immune response, possibly favouring susceptibility to tick infestations. (C) 2009 Elsevier B.V. All rights reserved.

Resistance of Santa Ines and crossbred ewes to naturally acquired gastrointestinal nematode infections

This trial was carried out in Piracicaba, Sao Paulo State. Brazil. to comparatively evaluate the degree of resistance to naturally acquired gastrointestinal nematode infections in sheep of the following genetic groups purebred Santa Ines (SI), SI crossbred with Dorper (DO x SI), lie de France (IF x SI), Suffolk (SU x SI), and Texel (TE < SI) Fifteen ewes from each group were raised indoors until 12 months of age. At this age, they were moved to pasture that was naturally contaminated by nematode infective larvae and were evaluated from December to May. 2007. Rainfall ranged from 267 mm in January to 37 mm in April Maximum and minimum mean temperatures ranged from 32 5 degrees C to 19 0 degrees C in March and from 25.9 degrees C to 12.8 degrees C in May. There was an increase in the mean number of eggs per gram of feces (EPG) after animals were placed on pasture with significant difference between the SI (80 EPG) and IF x SI (347 EPG) groups in January: and the DO x SI (386 EPG) and TE x SI (258 EPG) groups in May. The highest mean fecal egg count (FEC), 2073 EPG, was recorded for the TE x SI group in February. All groups showed a progressive reduction in body weight throughout the experiment of 12.0% (TE x SI) to 15.9% (SU x SI). In general. the animals with the highest FEC presented the lowest packed cell volumes (PCV): the highest correlation coefficient between FEC x PCV occurred in the SU x SI sheep in January (r = -0.70; P < 0.01). Similarly, there was an inverse relationship between FEC and blood eosinophil Values, with the highest correlation coefficient in the TE x SI sheep in February (r = -0.64; P < 0.05). Immunoglobulin G (IgG) levels against Haemonchus contortus antigens increased in all groups as a result of the exposure to parasites and remained relatively constant until the end of the study, with the exceptions of SU x SI and TE x SI, which showed a rise in IgG levels during the last sampling that coincided with a reduction in mean FEC. In conclusion. crossbreeding Santa Ines sheep with any of the breeds evaluated can result in a production increase and the maintenance of a satisfactory degree of infection resistance, especially against H. contortus and Trichostrongylus colubriformis. the major nematodes detected in this flock. (c) 2009 Elsevier B.V. All rights reserved.

Immunological responses and cytokine gene expression analysis to Cooperia punctata infections in resistant and susceptible Nelore cattle

Cellular and humoral immune response, as well as cytokine gene expression, was assessed in Nelore cattle with different degrees of resistance to Cooperia punctata natural infection. One hundred cattle (male, weaned, 11-12 months old), kept together on pasture, were evaluated. Faecal and blood samples were collected for parasitological and immunological assays. Based on nematode faecal egg counts (FEC) and worm burden, the seven most resistant and the eight most susceptible animals were selected. Tissue samples of the small intestine were collected for histological quantification of inflammatory cells and analysis of cytokine gene expression (IL-2, IL-4, IL-8, IL-1 2p35, IL-13, TNF-alpha, IFN-gamma, MCP-1, MCP-2, and MUC- 1) using real-time RT-PCR. Mucus samples were also collected for IgA levels determination. Serum IgG1 mean levels against C. punctata antigens were higher in the resistant group, but significant differences between groups were only observed 14 days after the beginning of the experiment against infective larvae (1-3) and 14 and 84 days against adult antigens. The resistant group also presented higher IgA levels against C. punctata (L3 and adult) antigens with significant difference 14 days after the beginning of the trial (P < 0.05). In the small-intestine mucosa, levels of IgA anti-L3 and anti-adult C. punctata were higher in the resistant group, compared with the susceptible group (P < 0.05). Gene expression of both T(H)2 cytokines (IL-4 and IL-13) in the resistant group and T(H)1 cytokines (IL-2, IL-1 2p35, IFN-gamma and MCP-1) in the susceptible group was up-regulated. Such results suggested that immune response to C. punctata was probably mediated by TH2 cytokines in the resistant group and by T(H)1 cytokines in the susceptible group. (C) 2008 Elsevier B.V. All rights reserved.

mRNA profile of Nellore calves after primary infection with Haemonchus placei

Haemonchus parasites are responsible for many losses in animal production. However, few studies are available, especially of zebu cattle. In this study, we investigated mRNA differences of immune response genes in naive Nellore calves infected with Haemonchus placei, relating these differences to patterns of cellular infiltrate. Calves were infected with 15,000 H. placei 13 larvae and after 7 days lymph node and abomasum tissues were collected. IL-2, IL-4, IL-8, IL-12, IL-13, IFN-gamma, MCP-1, lysozyme, pepsinogen and TNF-alpha genes were evaluated by qPCR. Mast cells, eosinophils and globular leukocytes were counted by abomasum histology. In the infected group, IL-4, IL-13 and TNF-alpha were up-regulated in the abomasal lymph node. In the abomasum, IL-13 increased and TNF-alpha was down-regulated (p < 0.05). No differences were detected for mast cells and eosinophil counts in abomasal tissue (p > 0.05). We conclude that for this infection time, there was Th2 polarization but that cellular infiltrate in abomasal tissue takes longer to develop. (C) 2010 Elsevier B.V. All rights reserved.

Zinc supplementation increases resistance to experimental infection by Trypanosoma cruzi

It is well recognized that zinc is an essential trace element for all organisms, influencing growth and affecting the development and integrity of the immune system. It is also well known that the protective response against Trypanosoma cruzi depends on both innate and acquired immunity and for the control of the parasite load and host survival, the participation of special cells such natural killer (NK), T and B lymphocytes and macrophages are required. So the aims of this study were to evaluate the effects of zinc supplementation on the host`s immune response infected with T cruzi. Our data point in the direction that zinc supplementation triggered enhanced thymocyte and splenocyte proliferation as compared to unsupplied group of animals. It is also important to emphasize that interleukin-12 (IL-12) participates in the resistance to several intracellular pathogens including T cruzi. Our findings demonstrate an enhanced production of IL-12 during the acute phase of infection in zinc-supplied groups. So we conclude that zinc supplementation leads to an effective host`s immune response by up-modulating the host`s immune response, thus contributing in the reduction of blood parasites and the harmful pathogenic effects of the experimental Chagas` disease. (c) 2008 Elsevier B.V. All rights reserved.