Veterinary Parasitology: X最新文献

{"title":"<i>Haemaphysalis longicornis:</i> the life-cycle on dogs and cattle, with confirmation of its vector status for <i>Theileria orientalis</i> in Australia.","authors":"Dominique Marendy, Kim Baker, David Emery, Peter Rolls, Ralph Stutchbury","doi":"10.1016/j.vpoa.2019.100022","DOIUrl":"https://doi.org/10.1016/j.vpoa.2019.100022","url":null,"abstract":"<p><p>The intracellular protozoal parasite <i>Theileria orientalis</i> ikeda has rapidly spread across South-eastern Australia since 2006, causing deaths and production losses in cattle. The 3-host \"bush tick\" <i>Haemaphysalis longicornis</i> (Neumann) appears the principal biological vector in the endemic regions. To generate sufficient numbers of ticks to produce stabilate for infection to confirm vector competency and for acaricide trials, the optimal conditions and stage-specific intervals for the generational life-cycle of <i>H.longicornis</i> was defined on two dogs and two steers. To determine whether <i>H.longicornis</i> was a definitive host for <i>Theileria orientalis,</i> nymphal stages were fed on a steer infected with <i>T.orientalis</i> and moulted adults were permitted to feed for 3 days on an uninfected calf prior to harvest. Subsequent detection of infection after inoculation of four naïve calves with stabilate produced from ground-up adult ticks or dissected salivary glands confirmed <i>H.longicornis</i> as one final (definitive) host for <i>T.orientalis</i> in Australia.</p>","PeriodicalId":23537,"journal":{"name":"Veterinary Parasitology: X","volume":"3 ","pages":"100022"},"PeriodicalIF":0.0,"publicationDate":"2019-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7458380/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149017935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bovine anaplasmosis herd prevalence and management practices as risk-factors associated with herd disease status.","authors":"Mark R Spare, Gregg A Hanzlicek, Kotie L Wootten, Gary A Anderson, Dan U Thomson, Michael W Sanderson, Roman R Ganta, Kathryn E Reif, Ram K Raghavan","doi":"10.1016/j.vpoa.2019.100021","DOIUrl":"https://doi.org/10.1016/j.vpoa.2019.100021","url":null,"abstract":"<p><p>Bovine anaplasmosis is a hemolytic disease of cattle caused by <i>Anaplasma marginale</i> which can cause anemia, adult mortality, abortion, and performance reduction. The objectives of this study were to estimate herd-level infection prevalence of bovine anaplasmosis in Kansas cow-calf herds and assess management practices associated with herd infection status. Licensed Kansas veterinarians were randomly selected and provided clientele to generate randomly selected participant herds. Blood samples were collected from 10 mature cows during processing of 925 herds between October 1, 2016 and March 1, 2017. A management survey was completed by 780 herd-owners. Sample status was determined by competitive enzyme-linked immunosorbent assay (cELISA); operations indicating vaccination for anaplasmosis were tested with <i>A.marginale</i>-specific polymerase chain reaction (PCR). Survey data underwent logistic regression analysis for calculation of odds ratios and confidence intervals. The herd-level prevalence was 52.5 % of cow-calf herds. Prevalence ranged from 19.1 % of herds in Western Kansas to 87.3 % of herds in Eastern Kansas. Vaccinated herds were more likely (OR = 2.38; CI = 1.16-4.85; <i>p</i> =  0.02) to be positive compared to non-vaccinated herds, and herds that utilized insecticide ear-tags were more likely to be positive (OR = 1.9; CI = 1.42-2.55; <i>p</i> < 0.01) compared to herds which do not. Operations that prescribe-burned 21-50 % and >50 % of their pastures were more likely to be test positive, OR = 5.74 (CI = 3 .14-10.51; <i>p</i> < 0.01) and OR = 4.78 (CI = 2.33-10.17; <i>p</i> < 0.01), respectively, than operations that prescribe-burned <20 % of their pastures. In summary, anaplasmosis is present across Kansas beef herds at varied prevalence levels and selected management practices were found to be associated with herd infection status.</p>","PeriodicalId":23537,"journal":{"name":"Veterinary Parasitology: X","volume":"3 ","pages":"100021"},"PeriodicalIF":0.0,"publicationDate":"2019-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7458371/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149017969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of counting duration on quantitative fecal egg count test performance.","authors":"Megan Slusarewicz, Paul Slusarewicz, Martin K Nielsen","doi":"10.1016/j.vpoa.2019.100020","DOIUrl":"10.1016/j.vpoa.2019.100020","url":null,"abstract":"<p><p>Fecal egg counts are the primary diagnostic tools of equine parasitology and use of the McMaster test and its variants in clinical practice is widely recommended. Manual counting is, however, prone to various sources of human error. For example, in real-world situations analysts can be under significant pressure to process high numbers of samples in a limited time. This practice could affect test result quality, but yet no studies have determined whether this is the case. This study's purpose was to assess the effect of shortened counting duration (from either restricting counting time or counting only one grid of a slide) on McMaster test performance, and to compare the results to those of an automated test whose output is not subject to such limitations. Fifteen fecal samples from horses infected with strongylid parasites were divided equally into three groups based on high, medium and low levels of egg content (201-500, 501-1000 and 1001+ eggs/g). Slurries were produced from each sample and 10 subsamples of each were counted by both the McMaster and automated methods. McMaster slides were first counted at leisure, and then twice again with counting time being restricted to either one or two min. The effect of reducing sample processing time by counting only one grid of the McMaster slide was also assessed. Counting for one min significantly decreased manual egg counts by 50-60% relative to counts conducted at leisure (p < 0.001). While these decreases were somewhat ameliorated by counting for two min, the results were still approximately 10% lower than the at-leisure counts, a difference that was also statistically significant (p < 0.001). Furthermore, restricted counting duration also resulted in a significant decrease of approximately one-third in McMaster test precision, as assessed by the coefficients of variation (CoVs) of the 10 replicates of each sample, as did counting just a single grid of the McMaster slide. These differences effectively further improved the observed superior precision of the automated method compared to at-leisure manual McMaster counting, and the automated counts and their precision remained relatively unaffected following multiple analyses of the same processed samples. Taken together, these results indicate that analysists should carefully assess the possible effects on test performance of modifications to standard egg-counting procedures that are designed to account for real-world pressures, in order to achieve an optimal compromise between test accuracy and precision on one hand and practicality on the other.</p>","PeriodicalId":23537,"journal":{"name":"Veterinary Parasitology: X","volume":"2 ","pages":"100020"},"PeriodicalIF":0.0,"publicationDate":"2019-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7458370/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147782606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of <i>Haemonchus contortus</i> on sheep farms increases using an enhanced sampling protocol combined with PCR based diagnostics.","authors":"Johan Höglund, Safaa T Elmahalawy, Peter Halvarsson, Katarina Gustafsson","doi":"10.1016/j.vpoa.2019.100018","DOIUrl":"https://doi.org/10.1016/j.vpoa.2019.100018","url":null,"abstract":"<p><p>An enhanced sampling strategy for detection of gastrointestinal parasites of sheep based on faecal sampling covering approximately 10% of the animals in the flock was evaluated with focus on the major sheep pathogen <i>Haemonchus contortus.</i> We also compared traditional diagnostics based on faecal eggs counts (FEC) by microscopy with DNA detection on frozen faeces samples using a droplet digital (dd)PCR assay. The investigation was carried out in 2018 in 20 conventional and 19 organic sheep flocks in Sweden with between 70 and 250 production ewes. On 76 different sampling occasions a total of 810 individual faecal samples were collected. Samples were pooled in the laboratory into 270 triplets which were examined both by microscopy and a ddPCR assay. On most farms (95%) a minimum of three triplets were investigated, first from the ewes prior to turn-out and later from the lambs after they had been grazing for at least six weeks. Extra information about the <i>Haemonchus</i> status was provided on 48% of the 76 sampling occasions by including more triplets compared with the old sampling strategy applied in Sweden before 2015 based on two triplets per sampling occasion irrespective of flock size. At a farm level <i>H. contortus</i> was identified by microscopy in 22 (56%) of the 39 flocks and by ddPCR it was found in 28 (72%) flocks with the enhanced protocol. There was a substantial agreement between the two diagnostic tests (Cohens kappa = 0.70 ± 0.087). No significant differences in infection levels were observed between the two production systems (conventional and organic) irrespective of the diagnostic method used. However, samples from the ewes were more often <i>Haemonchus</i> positive than those from the lambs indicating that the level of parasite control was in general acceptable. Combined, our results show that <i>Haemonchus</i> infection is widespread throughout Sweden. In conclusion, we have validated a practical tool for sheep producers to assess <i>Haemonchus</i> infection with high precision.</p>","PeriodicalId":23537,"journal":{"name":"Veterinary Parasitology: X","volume":"2 ","pages":"100018"},"PeriodicalIF":0.0,"publicationDate":"2019-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7458376/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149017836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morada Nova sheep breed: Resistant or resilient to <i>Haemonchus contortus</i> infection?","authors":"João Henrique Barbosa Toscano, Isabella Barbosa Dos Santos, Marei Borsch von Haehling, Luciana Aparecida Giraldelo, Louyse Gabrielli Lopes, Matheus Henrique da Silva, Amanda Figueiredo, Sérgio Novita Esteves, Ana Carolina de Souza Chagas","doi":"10.1016/j.vpoa.2019.100019","DOIUrl":"10.1016/j.vpoa.2019.100019","url":null,"abstract":"<p><p>Morada Nova is a Brazilian hair sheep breed that is well adapted to the country's mainly tropical climate and has good potential for meat and leather production. This breed is reported to be resistant to <i>Haemonchus contortus</i> infection, a highly desired characteristic due to the large impact of this parasite on sheep farming. Therefore, the present study aimed to characterize 287 recently weaned Morada Nova lambs and 123 ewes in relation to their resistance against <i>H. contortus</i>. The animals were dewormed and 15 days later artificially infected with 4000 <i>H. contortus</i> L₃ (D0). They were individually monitored by periodic assessment of fecal egg count (FEC), packed cell volume (PCV), and live weight (LW). On D42, the sheep were again dewormed and submitted to a new parasitic challenge, following the same scheme. The animals of each category (lambs and ewes) were ranked according to individual mean FEC values, and classified as resistant (R, 20%), intermediate (I, 60%), or susceptible (S, 20%) to <i>H. contortus</i> infection. At weaning, high FEC were observed in all three phenotypes (P > 0.05). After the artificial infections, there was a significant difference (P < 0.05) among the three lamb phenotypes for the mean FEC (R < I < S), PCV (R > I > S), and LW (R = I > S). The infection levels (FEC) were negatively correlated with PCV (r = -0.66; P < 0.001), and LW (r = -0.30; P < 0.001). Despite this, the lambs were resilient, since more than 88% of these animals maintained the PCV above 24%, even when heavily infected. The importance of selective parasite control before weaning to reduce the negative impact on slaughter weight was evidenced, taking into account the high positive correlation between LW at weaning and final LW (r = 0.73; P < 0.001). The ewes, in turn, were strongly resistant to the parasite. Despite highly significant differences (P < 0.001) for mean FEC between phenotypes (R < I < S), 98% of the ewes maintained FEC below 4000 EPG. Their health was not affected, since PCV and LW did not differ between phenotypes, and these parameters were not significantly correlated with FEC (P > 0.05). With the phenotypic characterization performed here, it is possible to introduce procedures for parasite control in Morada Nova flocks, facilitating the target-selective treatment approach. The results of this study can also support improvement of meat production by the Morada Nova breed.</p>","PeriodicalId":23537,"journal":{"name":"Veterinary Parasitology: X","volume":"2 ","pages":"100019"},"PeriodicalIF":0.0,"publicationDate":"2019-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7458387/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147700044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large-scale serological screening of slaughter pigs for <i>Toxoplasma gondii</i> infections in The Netherlands during five years (2012-2016): Trends in seroprevalence over years, seasons, regions and farming systems.","authors":"Manon Swanenburg, Jose L Gonzales, Martijn Bouwknegt, Gert Jan Boender, Derk Oorburg, Lourens Heres, Henk J Wisselink","doi":"10.1016/j.vpoa.2019.100017","DOIUrl":"https://doi.org/10.1016/j.vpoa.2019.100017","url":null,"abstract":"<p><p><i>Toxoplasma gondii</i> is the causative agent of the parasitic disease toxoplasmosis, which is an important foodborne zoonosis. Eating undercooked meat of infected animals, including pigs, has been considered the major transmission route of <i>T. gondii</i> to humans. Therefore, it is urgent to develop and implement intervention measures in the pork meat chain to reduce risks of acquiring a <i>T. gondii</i> infection. Proposed measures for control of <i>T. gondii</i> in pigs include serological testing of pigs and audits of pig farms on risk factors for <i>T. gondii</i> infection. So far, these ideas have not been tested in practice. In order to generate knowledge about the epidemiology and seroprevalence of <i>T. gondii</i>, as a basis for developing a surveillance system, we studied the long term seroprevalence over years, farming systems and regions, and seasonal patterns of <i>T. gondii</i> seroprevalence in Dutch slaughter pigs. During a five year study period from 2012 to 2016, serum samples were routinely collected in five Dutch pig slaughterhouses. The sera were tested in an ELISA for the presence of antibodies against <i>Toxoplasma</i>. In total 226,340 serum samples were collected and tested during the study period. The observed seroprevalence varied over years, with the highest overall seroprevalence in 2014 (2.8%) and the lowest in 2016 (1.4%). A higher seroprevalence was observed in pigs from organic farms compared to pigs from conventional farms. The overall risk of infection was on average 2.63 times significantly (p < 0.001) higher for organically raised pigs than for conventionally raised pigs. A seasonal pattern in seroprevalence was observed: the results showed a dominant annual periodicity with a seroprevalence peak in winter around week 1 and a minimum seroprevalence in summer around week 27. To our knowledge, this is the first large scale study on the seroprevalence of <i>T. gondii</i> in slaughter pigs. In comparison to other European serological studies, the observed seroprevalence seems to be relatively low. However, care is needed when comparing the results with other studies because of differences in test setup, the number of samples and time period of sampling. The results can be used as a starting point for developing a surveillance system for <i>T. gondii</i>, and for implementation of intervention measures.</p>","PeriodicalId":23537,"journal":{"name":"Veterinary Parasitology: X","volume":"2 ","pages":"100017"},"PeriodicalIF":0.0,"publicationDate":"2019-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7458374/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149017898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retrospective analysis of vector-borne infections in dogs after travelling to endemic areas (2007-2018).","authors":"Ingo Schäfer, Maria Volkmann, Pamela Beelitz, Roswitha Merle, Elisabeth Müller, Barbara Kohn","doi":"10.1016/j.vpoa.2019.100015","DOIUrl":"https://doi.org/10.1016/j.vpoa.2019.100015","url":null,"abstract":"<p><p>Canine vector-borne infections gained in importance in Germany due to growing tourist traffic, the increased import of dogs from abroad and the changing of climatic conditions. The Mediterranean region and southeastern Europe are geographical areas where pathogens such as <i>Leishmania</i> (<i>L</i>.) <i>infantum</i>, <i>Hepatozoon</i> (<i>H.</i>) <i>canis</i>, <i>Ehrlichia</i> (<i>E.</i>) <i>canis</i>, <i>Anaplasma</i> (<i>A.</i>) <i>platys</i> and <i>Dirofilaria</i> (<i>D.</i>) spp. are endemic. Meanwhile, <i>Babesia</i> (<i>B.</i>) spp. and <i>A. phagocytophilum</i> are present in central and western Europe. The objective of this retrospective study was to evaluate whether dogs were exposed to a corresponding risk of infection when travelling to regions in the Mediterranean area and southeastern Europe, which are endemic for these pathogens. Medical records and laboratory test results of 303 dogs that travelled to 14 countries endemic for the mentioned canine vector-borne pathogens and that were presented to the Small Animal Clinic at Freie Universität Berlin between 2007 and 2018 were retrospectively reviewed. A total of 1174 test results from external laboratories were descriptively analysed including 525 test results of direct and 649 of indirect determination methods. Overall, 13% of the tested dogs (40/303) were positive for at least one pathogen. Concurrent infections with two pathogens were detected in 1% of the dogs (4/303). The positive results were: <i>E. canis</i> 8% (18/231 dogs; Polymerase chain reaction [PCR] 3/73, indirect immunofluorescence test [IFAT] 18/209 dogs), <i>L</i>. <i>infantum</i> 5% (14/260 dogs; PCR 5/80, IFAT or enzyme linked immunosorbent assay [ELISA] 11/251 dogs), <i>Babesia</i> spp. 5% (11/232 dogs; <i>Babesia</i> spp. PCR 3/127, <i>B. canis/vogeli</i> IFAT or ELISA 8/160, <i>B. gibsoni</i> IFAT 2/22), <i>Dirofilaria</i> spp. 1% (1/133 dogs; <i>D. immitis</i> antigen-ELISA 1/117, microfilariae PCR 0/16, Knott´s test 0/69 dogs). None of the dogs has been tested positive in a combined <i>Babesia</i> spp./<i>Hepatozoon</i> spp. PCR test (0/15 dogs) and for <i>H. canis</i> (0/17 dogs; PCR) or <i>A. platys</i> (0/11 dogs; PCR). There is a substantial risk for dogs travelling to areas endemic for vector-borne pathogens even with limited time of exposure to get infected. The data indicates the importance of owner education and prophylactic measurements against vector-borne infections in dogs travelling to endemic areas.</p>","PeriodicalId":23537,"journal":{"name":"Veterinary Parasitology: X","volume":"2 ","pages":"100015"},"PeriodicalIF":0.0,"publicationDate":"2019-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7458389/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149018008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the pour-on administration of eprinomectin on milk yield and somatic cell counts in dairy ewes naturally infected with gastrointestinal nematodes.","authors":"K Arsenopoulos, A I Gelasakis, V Delistamatis, E Papadopoulos","doi":"10.1016/j.vpoa.2019.100016","DOIUrl":"https://doi.org/10.1016/j.vpoa.2019.100016","url":null,"abstract":"<p><p>The effect of pour-on eprinomectin administration on milk yield and somatic cell counts was studied in dairy ewes located on twelve farms in mainland Greece. On each farm, the selected ewes were randomly divided into three similar groups. Group 1 consisted of 10-15 untreated ewes (control group), Group 2 consisted of 10-13 ewes treated with a single dose of eprinomectin at Day 0 and Group 3 consisted of 6 ewes repeatedly treated with eprinomectin at Days 0, 42 and 70. Faecal egg counts and coprocultures were performed on Days 0, 7, 14, 28, 42, 56, 70, 84 and 98. The milk yield and somatic cell counts were measured. The topically administered eprinomectin was highly effective against gastrointestinal nematodes up to 42 days post treatment (94.1% and 99.7% for Groups 2 and 3, respectively). This beneficial effect was extended from Day 42 to 98, in ewes of Group 3. Ewes treated once or thrice presented an increase of daily milk yield by <i>ca.</i> 5% (50 mL/day) and 11% (105 mL/day), respectively, compared to untreated ewes. At the same frame, a significant decrease in somatic cell counts was observed in the eprinomectin treated ewes compared to the untreated ones. In conclusion, this study confirmed the high antiparasitic efficacy and the beneficial effect of pour-on eprinomectin on the milk yield and somatic cell counts in dairy ewes under semi-intensive management.</p>","PeriodicalId":23537,"journal":{"name":"Veterinary Parasitology: X","volume":"2 ","pages":"100016"},"PeriodicalIF":0.0,"publicationDate":"2019-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7458382/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149017892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Trypanosoma vivax</i> infection in sheep: Different patterns of virulence and pathogenicity associated with differentially expressed proteomes.","authors":"Roger Ramirez-Barrios, Armando Reyna-Bello, Omaira Parra, Robert Valeris, Lucinda Tavares-Marques, Jean-Paul Brizard, Edith Demettre, Martial Seveno, Alvaro Martinez-Moreno, Philippe Holzmuller","doi":"10.1016/j.vpoa.2019.100014","DOIUrl":"https://doi.org/10.1016/j.vpoa.2019.100014","url":null,"abstract":"<p><p>Cattle trypanosomosis caused by <i>Trypanosoma vivax</i> is a widely distributed disease in Africa and Latin America. It causes significant losses in the livestock industry and is characterized by fluctuating parasitemia, anemia, fever, lethargy, and weight loss. In this study we evaluated the virulence (capacity to multiply inside the host and to modulate the host response) and pathogenicity (ability to produce disease and/or mortality) patterns of two <i>T. vivax</i> strains (TvMT1 and TvLIEM176) in experimentally-infected sheep and determined the proteins differentially expressed in the proteomes of these two strains. Hematological and clinical parameters were monitored in experimentally-infected versus non-infected sheep for 60 days. All the infected animals developed discernable parasitemia at 3 days post-infection (dpi), and the first parasitemia peak was observed at 6 dpi. The maximum average value of parasitemia was 1.3 × 10⁷ (95% CI, 7.9 × 10⁵-2 × 10⁸) parasites/ml in TvLIEM176-infected animals, and 2.5 × 10⁶ (95% CI, 1.6 × 10⁵-4 × 10⁷) parasites/ml in TvMT1-infected ones. Anemia and clinical manifestations were more severe in the animals infected by TvMT1 strain than in those infected by TvLIEM176. In the proteomic analysis, a total of 29 proteins were identified, of which 14 exhibited significant differences in their expression levels between strains. Proteins with higher expression in TvLIEM176 were: alpha tubulin, beta tubulin, arginine kinase, glucose-regulated protein 78, paraflagellar protein 3, and T-complex protein 1 subunit theta. Proteins with higher expression in TvMT1 were: chaperonin HSP60, T-complex protein 1 subunit alpha, heat shock protein 70, pyruvate kinase, glycerol kinase, inosine-5'-monophosphate dehydrogenase, 73 kDa paraflagellar rod protein, and vacuolar ATP synthase. There was a difference in the virulence and pathogenicity between the <i>T. vivax</i> strains: TvLIEM176 showed high virulence and moderate pathogenicity, whereas TvMT1 showed low virulence and high pathogenicity. The proteins identified in this study are discussed for their potential involvement in strains' virulence and pathogenicity, to be further defined as biomarkers of severity in <i>T. vivax</i> infections.</p>","PeriodicalId":23537,"journal":{"name":"Veterinary Parasitology: X","volume":"2 ","pages":"100014"},"PeriodicalIF":0.0,"publicationDate":"2019-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7458391/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149017542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence of <i>Strongylus vulgaris</i> in horses after ten years of prescription usage of anthelmintics in Sweden.","authors":"Eva Tydén, Heidi Larsen Enemark, Mikael Andersson Franko, Johan Höglund, Eva Osterman-Lind","doi":"10.1016/j.vpoa.2019.100013","DOIUrl":"https://doi.org/10.1016/j.vpoa.2019.100013","url":null,"abstract":"<p><p><i>Strongylus vulgaris</i> is considered the most pathogenic nematode parasite of the horse. Frequent deworming programs since the 1970s have reduced the prevalence of <i>S. vulgaris</i> to low levels, but to the price of widespread benzimidazole resistance in the small strongyles (cyathostominae) and ivermectin resistance especially in the equine roundworm <i>Parascaris</i> spp. To slow down the progression of anthelmintic resistance in Sweden, horse anthelmintics were made prescription only medicine in 2007 and selective therapy principles were introduced. This means that only individuals with high egg excretion or clinical signs of helminth infection were treated instead of blanket treatment of all horses on a farm. The aims of this study were to investigate the prevalence and risk factors associated with <i>S. vulgaris</i> infection in Sweden ten years after the introduction of a selective therapy regime. A total of 529 faecal samples from 106 farms were collected during March to June in 2016 and 2017. A web-based questionnaire was used to collect information about deworming routines. Strongyle faecal egg counts (FEC) were performed by McMaster and presence of <i>S. vulgaris</i> was demonstrated with a specific PCR on individual larval cultures. Results were analysed by mixed logistic (<i>S. vulgaris</i> prevalence) or linear (FEC) regression models, where farm was included as random factor. The overall prevalence of <i>S. vulgaris</i> at individual and farm levels was 28% and 61%, respectively. We observed a 2.9 increased odds risk of <i>S. vulgaris</i> infection on farms that based their treatment on strongyle FEC only as compared to farms that complemented strongyle FECs with larval cultures or dewormed regularly, 1-4 times per year, without prior diagnosis. We found no association between the prevalence of <i>S. vulgaris</i> and strongyle FEC level, horse age, geographical region or signs of colic. The prevalence of <i>S. vulgaris</i> was 25% in horses shedding ≤150 eggs per gram. Thus horses with low strongyle FECs that are left untreated could be an important source of <i>S. vulgaris</i> infection. This may be an important reason for the approximately three-fold increase in <i>S. vulgaris</i> prevalence since 1999 in Sweden. However, our combined results indicate that selective therapy based on a combination of strongyle FECs and larval cultivation was not associated with an increased risk of <i>S. vulgaris</i> infection. Still, <i>S. vulgaris</i> needs to be monitored continuously and should be taken into careful consideration when the treatment frequency is reduced.</p>","PeriodicalId":23537,"journal":{"name":"Veterinary Parasitology: X","volume":"2 ","pages":"100013"},"PeriodicalIF":0.0,"publicationDate":"2019-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7458386/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149018024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}