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Copyright of Bulletin de la Société de Pathologie Exotique is the property of John Libbey Eurotext Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Capparis spinosa is cultivated for several proprieties and the different parts of the plant (flower buds, fruits, leaf and seeds) have been employed in drugs, foods and cosmetics. This study aimed to explore the antioxidant potential effect and to assess the anthelmintic efficacy of an aqueous extract of Capparis spinosa. In vitro antioxidant activity of aqueous extracts from the fresh leaves and flower buds of C. spinosa was measured by determining free radical-scavenging activity against DPPH and ABTS radical cations. In vitro anthelmintic activities against eggs and adult worms of Haemonchus contortus from sheep were investigated in comparison to albendazole. DPPH and ABTS activities of both aqueous extracts increased in a dose dependent manner. The IC50 values of aqueous extracts from fresh leaves, flowers buds and ascorbic acid in the DPPH radical scavenging assay were 101.40; 70.40 and 57.56 µg/ml, respectively. The IC50 values of aqueous extracts fresh leaves, flowers buds and ascorbic acid in the ABTS radical scavenging assay were 110; 87.89 and 58.17 µg/ml, respectively. Both plant extracts showed ovicidal activity at all tested concentrations. The aqueous extract from flower buds (IC50 = 2.76 mg/ml) showed higher inhibitory effects (P < 0.05) than aqueous extract from leaves (IC50 = 8.54 mg/ml) in the egg hatching assay. The aqueous extract from flower buds inhibited more worms than the aqueous extract from leaves at all tested concentrations. After 6 h of exposure, the highest tested concentrations of aqueous extracts from flower buds and leaves induced 100 and 41.66% inhibition of motility, respectively. These results show for the first time that C. spinosa possesses in vitro anthelmintic properties which may be related to its high content of phenolic compounds such as flavonoids and tannins. [ABSTRACT FROM AUTHOR]

Purpose – The authors consider a system which is a part of a complex equipment (e.g. aircraft, automobile, medical equipment, production machine, etc.), and which consists of N independent series subsystems. The purpose of this paper is to determine simultaneously the system design (reliability) and its preventive maintenance (PM) replacements periodicity which minimize the total average cost per time unit over the equipment useful life, taking into account a minimum required reliability level between consecutive replacements. Design/methodology/approach – The problem is tackled in the context of reliability-based design (RBD) considering at the same time the burn-in of components, the warranty commitment and the maintenance strategy to be adopted. A mathematical model is developed to express the total average cost per time unit to be minimized under a reliability constraint. The total average cost includes the cost of acquiring and assembling components, the burn-in of each component, preventive and corrective replacements performed during the warranty and post-warranty periods. A numerical procedure is proposed to solve the problem. Findings – For any given set of input data including components reliability, their cost and the costs of their preventive and corrective replacements, the system design (reliability) and the periodicity of preventive replacement during the post-warranty period is obtained such as the system’s total average cost per time unit is minimized. The obtained results clearly indicate that a decrease in the number of PM actions to be performed during the post-warranty period increases the number of components to be added at each subsystem at the design stage. Research limitations/implications – Given that the objective function (cost rate function) to be minimized is non-linear and involves several integer variables, it has not been possible to derive the optimal solution. A numerical procedure based on a heuristic approach has been proposed to solve the problem finding a nearly optimal solution for a given set of input data. Practical implications – This paper offers to manufacturers a comprehensive approach to look for the most economical combination of the reliability level to be given to their products at the design stage, on one hand, and the PM policy to be adopted, on the other hand, given the offered warranty and service for the products and reliability requirements during the life cycle. Originality/value – While the RBD problem has been largely treated, most of the published works have focussed on the development or the improvement of solving techniques used to find the optimal configuration. In this paper the authors provide a more comprehensive approach that considers simultaneously RBD, the burn-in and warranty periods, along with the maintenance policy to be adopted. The authors also consider the context of products whose component failures cannot be rectified through repair actions. They can only be fixed by replacement. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin de la Société de Pathologie Exotique is the property of John Libbey Eurotext Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The authors presents a survey of gastrointestinal helminths of sheep on permanent pastures in the extreme north area of Tunisia. It was noted that the animals are under a rudimentary shelter and outdoor when it is warmer during cold season. The owner used self-medication with albendazole generics only on sheep with clinical symptoms, which suggests gastrointestinal helminthiasis with no knowledge of the drug activity. It was said that 45.5 and 52.8 percent of the parasitic population of tracer lambs were discovered in the abomasum and small intestine respectively.

Attenuated vaccines are an important means of controlling Theileria annulata infection of cattle. Production is by prolonged cultivation of macroschizont-infected cells. The mechanism of attenuation remains unclear. There are three general nonmutually exclusive possibilities: Selection of avirulent subpopulations, genome rearrangements and alterations in gene expression. Several groups, including ours, have provided evidence that the population structure usually tends to simplify during attenuation. Our data on the T. annulata (Ta) Ankara cell line show that attenuation is not necessarily accompanied by the population becoming clonal. We have been unable to detect large DNA rearrangements. Evidence for alterations in host and parasite gene expression during attenuation is available. With respect to the host we have shown that attenuation is accompanied by loss of expression of parasite induced matrix metalloproteinases (MMPs). However, in different lines different protease activities are involved. In the T. annulata Ode line we have shown that 8 activities (including MMP9) are downregulated and that this correlates with a loss of metastatic behaviour. This has previously been shown in vitro using reconstituted basement membrane (Matrigel) and is demonstrated in vivo using scid mice in this study. Thus part of the pathology, namely the ability to disseminate, mediated by host MMPs, is lost upon attenuation. Re-isolation experiments have shown that the reduction/loss of MMP is a stable transferable trait. A logical extension is that loss of MMP activity (and virulence in general) must be at the most fundamental level a genetic trait of the parasite. Evidence for loss of parasite gene expression is implied by the loss of the ability to differentiate into merozoites on attenuation. Specific evidence for loss of parasite gene expression has been obtained using differential RNA display. We view virulence as a multifactorial phenomenon involving interacting subpopulations of cells and attenuation is a threshold effect whereby the number of virulence factors is reduced below a critical level. On this basis there will be many different ways to achieve attenuation. [ABSTRACT FROM AUTHOR]

The article discusses a research study on evaluating the culture protocol of Theileria annulata using blood from experimentally infected cattle. Study subjects include two groups of 20 Holstein-Frisian bovines infected experimentally with Theileria annulata in lethal doses of 1.8 and 0.25 equivalent ticks of ground up tick supernates (GUTS). Monitoring of cell cultures were done through cytospin smears and then examined microcopically for T. annulata schizont infected cells were the Giemsa stained cells. Conclusions indicated the effectivity of the rapid protocol in terms of money and time savings. It notes performance of new technique in minutes with savings of 3.0 euros per sample as compared to conventional technique requiring up to three hours.

Toxoplasmosis is an important zoonosis caused by an obligate intracellular parasitic protozoan, Toxoplasma gondii. The disease is distributed worldwide and can affect all warm-blooded vertebrates, including humans. The present review aimed to collect, compile and summarize the data on the prevalence of T. gondii infection in humans and animals in the five North African countries (Morocco, Algeria, Tunisia, Libya and Egypt). Published data from national and international databases were used. Distribution patterns and risk factors for T. gondii infection are discussed, focusing on biotic and abiotic factors. This review is a comprehensive epidemiological analysis of T. gondii infection in North Africa and will therefore be a useful tool for researchers. It can also be used to propose or enhance appropriate national toxoplasmosis control programs.

In this study, the prevalence of piroplasms in sheep and goats was assessed with Giemsa-stained blood smear examination, PCR and nested PCR-restriction fragment length polymorphism (RFLP) to identify Babesia and Theileria species, respectively, in 338 small ruminants (172 sheep and 166 goats) from three sites in North-West Tunisia during the 2011 summer season. The overall infection prevalence of piroplasms in Giemsa-stained blood smears was 3.2% (11/338), with a parasitaemia ranging from 0.01 to 0.05%. PCR detected two species, namely Babesia ovis (in sheep and goats) and Theileria ovis (in sheep), with an overall prevalence of 16.3%. The molecular prevalence of B. ovis was significantly higher in sheep than in goats (17.4% and 9%, respectively, p = 0.034). The same trend was observed for T. ovis in sheep and goats (5.8% and 0%, respectively, p = 0.004). Comparison of the partial sequences of the 18S ssu rRNA gene revealed 100% similarity amongst Babesia from sheep and goats. The single Theileria sequence in this study showed 100% similarity to T. ovis. A high similarity with all the blasted genotypes was reported for Theileria and Babesia sequences. This is the first molecular detection of B. ovis and genetic characterisation of small ruminants’ piroplasms in Africa.

The authors present an overview of canine leishmaniosis due to Leishmania infantum. This protozoan is transmitted by sandflies and the disease is frequently characterised by chronic evolution. Cutaneous and visceral clinical signs appear as the infection progresses. Lymph node enlargement, emaciation and skin lesions are the main signs observed in the classical forms of the disease. Control is difficult since infected dogs remain carriers for years and may relapse at any time. The mass screening of infected animals and their treatment or euthanasia represent the best way to reduce the prevalence of this disease in endemic regions. Further research is needed to improve the efficiency of the vaccines available to protect dogs against infection. This disease is zoonotic; in humans, clinical cases are reported mainly in elderly people, the young and those whose immune systems have been compromised.

The aim of the study was to evaluate the seroprevalence of Anaplasma phagocytophilum in dromedary (Camelus dromedarius). Sera of 226 healthy dromedaries from three regions of Tunisia (Sidi Bouzid, Bouficha and Douz) were tested by indirect immunofluorescence (IFA). The overall infection rate was estimated at 29.2%. The study of risk factors showed that region, age, gender, presence of ticks and types of breeding had no influence on the seroprevalence of A. phagocytophilum. This study indicates for the first time in Tunisia that dromedary may be involved in the natural cycle of A. phagocytophilum.

This cross-sectional study is the first to estimate the prevalence of cattle pediculosis in Tunisia. A total of 39 cattle farms in the region of Nabeul in north-east Tunisia were visited and lice were collected by intensively brushing 789 cattle. The prevalence was estimated to be 20.5% on the farms (8/39) and 4.7% in animals (37/789). Collected parasites were examined under a stereomicroscope and three lice species were identified: Bovicola bovis, Linognathus vituli and Haematopinus eurysternus. Thirty-two animals were infested with the chewing lice B. bovis (4%), three with H. eurysternus (0.4%) and two with L. vituli (0.2%). The infestation prevalence was higher in calves under eight months of age (21.6%)than in adults (0.8%). Decision-makers in animal health should consider this parasitic disease in their control and eradication programmes., (© World Organisation for Animal Health (OIE), 2013)

Ovine fasciolosis causes high morbidity and mortality rates, resulting in large economic losses to the sheep industry in northern Tunisia. The authors surveyed ovine fasciolosis (Fasciola hepatica infestation) in a Barbarine sheep flock in the humid region of Tunisia (Sejnane, Governorate of Bizerte) over two consecutive years, 2004 to 2005. To assess the dynamics of fluke infestation, a total of 36 tracer lambs were introduced into the flock successively, in groups of three, every two months, and their infestations were monitored by coproscopy and necropsy. Coproscopic analysis revealed high mean percentages of infestation of 60% and 65% for flock lambs and ewes, respectively. Similarly, a high percentage of infestations was recorded in the tracer lambs (more than 70%) post mortem. Significant fluctuations in infestation dynamics were observed in the tracer lambs, and three distinct infestation periods were identified: a period of very low, non-constant infestation risk during the warm period (from July to October); a high-risk period from March to June, and a third period with a variable but constant infestation risk (from November to February). Based on these results, the authors propose strategic flukicide treatments with triclabendazole, aimed at reducing mollusc infestation and subsequent pasture contamination by metacercariae, during two main periods: in September and in February, just before the reactivation of the molluscs from aestivation and hibernation, respectively.

An economic evaluation of various control programmes against Theileria annulata infection was conducted on a sample of 49 Tunisian dairy farms where clinical cases of tropical theileriosis had been recorded during the summer. Indicators of morbidity and the prevalence of infection, as well as production and demographic indicators (recorded in the present survey ortaken from secondary sources), were used to rank the potential costs and benefits of various control programmes for tropical theileriosis over a time horizon of 15 years. Three options were considered, i.e. vaccination with a local attenuated cell-line vaccine; partial barn upgrading, based on first roughcasting then smoothing all the walls of the animal premises (inner and outer surfaces); and applying acaricides to control the vector tick population on the cattle. The most important loss from this disease, representing between 22% and 38% of the overall losses, is the loss in milk yield from carriers of T. annulata. Upgrading barns produced the highest mean benefit-cost ratio (1.62 to 3.71), while the ratios for vaccination and acaricides ranged from 0.20 to 1.19 and 0.32 to 0.88, respectively. However, the benefit-cost ratio of vaccination increased (from 1.65 to 5.41), when the costs due to carrier state infection, which vaccination does not prevent, were ignored. Upgrading barns is a sustainable eradication policy against tropical theileriosis, based on a single investment, and is environmentally friendly. This control option should be encouraged by national Veterinary Authorities in regions where tropical theileriosis is transmitted by a domestic endophilic tick.

Tropical theileriosis, caused by the tick-transmitted protozoan Theileria annulata, is a major disease of cattle in many regions of the developing world. Development and deployment of current and novel control strategies should take into account the potential diversity of parasite populations and therefore it is important that the nature and basis for this genetic variation is investigated and quantified. The recently completed genome sequence of T. annulata provided an opportunity to develop a panel of genetic markers for population studies. Bioinformatic screening of the genome sequence identified micro- and mini-satellite loci, which were PCR amplified from a series of diverse parasite stocks in order to characterise their polymorphism and determine their species-specificity. A panel of 10 polymorphic markers was then selected for population genetic studies and used to genotype both cloned and uncloned isolates maintained as cell lines of T. annulata isolated from different countries. Uncloned isolates comprised a multiplicity of genotypes, while cloned isolates showed evidence of a single haploid genome. Population genetic analysis revealed a high level of genotypic diversity both between and within countries, as measured by the number of distinct multilocus genotypes. Based on measures of genetic differentiation (F(ST) and Nei's genetic distance), the parasite populations are geographically sub-structured and these measurements positively correlate with geographical distance. To investigate whether genetic exchange occurs at random and the populations are panmictic, the level of linkage disequilibrium was measured using the index of association across all loci. Linkage disequilibrium was observed when isolates from all countries were treated as a single population but when the isolates from Tunisia were analysed separately, linkage equilibrium was observed.

Epidemiological, clinical and parasitological data concerning canine leishmaniasis were collected in two Tunisian populations of dogs, different in breed and life style: 23 rural dogs and 26 dogs of European breeds. All were symptomatic and lived in the north of Tunisia where human visceral and cutaneous leishmaniasis caused by Leishmania infantum are endemic. Leishmaniasis has been confirmed in all dogs by serology or/and by parasitic identification. Significant differences concerning age and symptoms suggest a higher susceptibility to infection in European imported breeds. In fact individuals of this population were significantly younger; 81% were less than 5 years old whereas 57% of the autochthonous rural dogs were more than 5 years old with 31% of them being older than 9 (p = 0.014). In spite of their young age, 75% of imported breeds presented an affection of their general state with more frequent cutaneous symptoms than the rural dogs (96% versus 69%, p = 0.02). Isoenzyme typing of 31 strains, obtained from the two populations, from different sites (blood, lymph nodes, spleen) has only identified the zymodeme Leishmania infantum MON-1. This stresses the need of more investigations to determine reservoirs of the other enzymatic variants identified in humans in Tunisia and Mediterranean basin.

The Indirect Fluorescent Antibody Test (IFAT) remains so far the most commonly used test for sero-epidemiological investigations on tropical theileriosis (infection of cattle with Theileria annulata). The present studies evaluated the ability of both IFAT with schizont antigen (schizont IFAT) and blood smears to detect infected animals just after the theileriosis season. This evaluation was performed on a group of 89 calves of known infection status for T. annulata at first disease season, from farms with endemic stability for tropical theileriosis. An additional retrospective group of 84 cattle free of infection was also used for the estimation of the specificity of the schizont IFAT. The sensitivity and the specificity of schizont IFAT were 88.9% (64/72) and 97% (98/101), respectively. Blood smears showed a lower sensitivity of 63.9% (46/72). The agreement between the two detection techniques and the infection status of the animals, evaluated by the Kappa coefficient, was 0.85 and 0.64 for IFAT and blood smears, respectively.

Several species of piroplasms of livestock are present in Tunisia; some of them are of high veterinary importance. This paper reviews the species already reported in Tunisia on the basis of clinical observations, parasitological routine diagnostic and serological surveys, as well as those considered as potentially present according to epidemiological argumentations. The genus Theileria includes four species reported in Tunisia: T. annulata, T. buffeli, T. ovis, and T. equi. The ovine malignant theileriosis agent, T. lestoquardi, appears to be absent in Tunisia. Five species belonging to the genus Babesia were reported in the country, namely B. hovis, B. bigemina, B. divergens, B. caballi, and B. ovis. Furthermore, two more species, B. major and B. motasi, are potentially present in zones where their vectors of the genus Haemaphysalis occur.

There is increasing evidence that immune mechanisms are involved in the pathogenesis of many parasitic infections, including infections with the tick-borne protozoan Theileria annulata. The initial stages of tropical theileriosis are characterised by the induction of a non-specific lymphoproliferation by schizont-infected cells which is believed to disrupt antigen recognition and interfere with protective immune responses. This study examined the possibility that cattle do not always succumb to infection because macrophages suppress this non-specific lymphoproliferation. The results provide evidence that lymphoproliferation in cattle may be controlled by two types of suppressor macrophages. The first type occurs in infected cattle and acts via a feedback loop well documented in other parasitic infections. This loop involves macrophages, apparently activated by high levels of gamma interferon produced by proliferating lymphocytes, which suppress lymphocyte proliferation via a prostaglandin-mediated pathway. The properties of a suppressor activity seen in immunised and challenged animals suggested that cattle also possess a type of novel suppressor macrophage recently described in filarial infections. This second type of suppressor macrophage does not seem to act via prostaglandin; its activity appeared to be linked to a suppressor epitope on the sporozoite antigen SPAG-1. Differences in the nature of the schizont-infected cells of the Friesian and Sahiwal calves used in one section of this work, in the in vitro and in vivo lymphoproliferative responses of the two groups of calves and in the behaviour of their suppressor macrophages suggested several reasons why the outcome of Theileria infections differed in the two cattle breeds. This study has extended our knowledge of the pluripotential activities of macrophages in T. annulata infections to include immunosuppression as well as anti-parasite responses and confirmed the view that the outcome of infection with T. annulata, as with many parasitic infections, depends upon the final balance of the protective and pathological properties of the immune system.

Ticks (Ixodidae) play a significant role as vectors of pathogens of domestic animals in Tunisia. The major losses caused by ticks are related to transmission of protozoan parasites. These include agents of tropical theileriosis and babesiosis in ruminants. Since 1991, we conducted research studies on tick population of livestock in Tunisia. This overview reports a synthesis on tick distribution, their biology and their role as vectors of pathogens in domestic animals, particularly cattle. During the whole period of the study about 15,000 tick specimens were collected from different zones of the country. A total of 14 species were identified. Hyalomma detritum detritum was the most abundant and important (vector of Theileria annulata) species infesting cattle. Hyalomma dromedarii and Hyalomma impeltatum were collected on domestic ruminants in the arid and desertic zones. Hyalomma marginatum marginatum and Hyalomma anatolicum excavatum were widespread and found on livestock hosts. Ixodes ricinus, vector of Babesia divergens and Borrelia burgdorferi sl, colonises mainly the humid zone. Boophilus annulatus and Rhipicephalus bursa infesting cattle, sheep and goats were found in the sub-humid and semi-arid zones. Haemaphysalis sulcata and Hae. punctata were collected in humid and sub-humid zones on cattle and sheep. Rhipicephalus turanicus were collected in different regions, on different animal species. Rhipicephalus sanguineus, tick of dogs, were often collected on livestock. Only few specimens of Hyalomma marginatum rufipes and Hyalomma franchinii were collected.

In Tunisia, tropical theileriosis (Theileria annulata infection of cattle) is one of the major diseases affecting cattle in the summer. Each year about 2,500 clinical cases are recorded in the country, mainly in pure-bred animals. An attempt was made in the North of Tunisia to estimate the direct cost related to clinical cases of TT. In the endemic regions, three states of endemicity were described according to cattle age categories at highest disease risk: (i) endemic stability, (ii) low endemic instability, (iii) high endemic instability. The characterisation of these endemic situations, which are conditioned by the levels of the vector tick population and the quantitative aspects of the infection in ticks, are highly relevant for the development of a live attenuated cell line vaccine against TT targeting the cattle population at disease risk in Tunisia. A research programme was set up to develop the attenuation of four local parasite stocks. Two cell lines infected with two distinct T. annulata stocks were tested in the field on pure-bred animals of different age groups from regions with high disease incidence. The vaccination with each of the two cell lines showed a high efficacy. However significant differences in vaccine reactions rates were observed between the two attenuated cell lines emphasising the importance of achieving an optimal balance between protection and vaccine tolerance particularly in pure-bred lactating cows.