Search

Fasciolosis is one of the most important parasitic diseases in ruminants in Algeria, of which the intermediate host is Galba truncatula (G. truncatula) snail. The current study aimed to investigate the prevalence of Fasciola sp. in naturally infected G. truncatula snails using multiplex PCR. Secondly, it was targeted toward examining the rate of growth, survival, and laying of the snails in experimental conditions during 6 weeks of rearing in three tanks. This study was conducted in two different regions of Algeria, namely El Tarf and Constantine. The investigated tanks 1, 2, and 3 consisted of 12 (size 3-4 mm), 30 (size 5-6 mm), and 30 (size 7-8 mm) snails, respectively. Fasciola sp. DNA was detected in 33.33% of G. truncatula snails (25% in Constantine and 42.85% in El Tarf). The total survival rates in the first, second, and third tanks were 50%, 43.3%, and 40%, respectively. The obtained results indicated that the growth rate of the snail depended on its initial size (the smaller the initial size, the higher the weekly growth rate). The total growth rates were 3, 1.7, and 1.1 mm in tanks 1, 2, and 3, respectively. The use of multiplex PCR indicated a relatively high level of infestation of the snails by Fasciola sp. Snails larger than 7 mm had the highest lay rate. Further studies are needed to investigate other snails that may be infested with Fasciola sp.

This study aimed to demonstrate the existence of a possible correlation between the level of liver fluke infection in cattle caused by Fasciola hepatica and the titers of anti-parasite antibodies in the blood. 113 blood samples were taken from non-dewormed pasture cattle in the communal slaughterhouse of the Jijel city in order to determine the serological titration of anti-fluke antibodies by the ELISA method. After slaughtering the animals studied, a count of parasites present in the inspected livers was carried out in order to assess the level of parasitic infection. The prevalence of bovine fasciolosis (due to Fasciola hepatica) based on counting the number of flukes in the inspected livers was around 61.06%, while the seroprevalence obtained is 55.75%. The sensitivity and specificity of the ELISA test used in this study were, respectively, 91.3% and 100%. A very strong correlation (r = 0.93 to p

This study aims to investigate, for the first time in Algeria, the effect of seasonal climatic changes on the hematological profile of Holstein dairy cows as an indicator for their physiological status assessment. The study was conducted between November 2018 and October 2019 and was performed on a lot of 14 dairy cows. Blood samples were collected quarterly during this study period. The data regarding seasonal changes in hematological parameters were not significant concerning red blood cell count (RBC), hemoglobin concentration (Hb) and mean corpuscular volume (MCV). However, variations were significant for hematocrit (HCT), mean corpuscular hemoglobin content (MCH), mean corpuscular hemoglobin concentration (MCHC) and blood platelets (PLT). The percentage of HCT was higher in autumn (27.99%) and spring (28.58%) compared to winter (26.52%) and summer (26.75%), (p

This study aims to investigate, for the first time in Algeria, the variations of hematological and ionic parameters of Holstein dairy cows according to the physiological stage, as an indicator of its health status. The survey was conducted between January and March 2020 and carried out on 4 lots of 15 dairy cows each. The analysis of blood parameters concerned: red blood cells (RBC), hematocrit (HCT), hemoglobin (HGB), mean corpuscular volume (MCV), mean corpuscular hemoglobin content (MCH), mean corpuscular hemoglobin concentration (MCHC), platelets (PLT), the white blood cells (WBC), lymphocytes (LYM), monocytes (MONO), neutrophils (NEU), eosinophils (EOS), basophils (BASO) and ionic parameters such as potassium (K), chlorine (Cl), calcium (Ca), phosphorus (P) and sodium (Na). The RBC level was lowest in the 2nd third of gestation (6.0 ± 0.8 x 106/µL) and in postpartum period (5.6 ± 0.8 x 106/µL), in comparison to the 1st third (6.6 ± 0.6 x 106 / µL) and 3rd third (dry period) of gestation (6.7 ± 0.5 x 106 / µL) (pst third of gestation compared to the other stages, (11.3 ± 2.2 x 103 / µL) versus (6.4 ± 4.1 x 103 / µL), (5.2 ± 1.3 x 103 / µL), and (8.0 ± 4.9 x 103 / µL) for the 2nd third, 3rd third of gestation, and postpartum, respectively (p

The prevalence of Fasciola hepatica infection in the snail Galba truncatula was studied for the first time in Algeria using Multiplex PCR. A total of 722 individuals were collected from 11 typical habitats (temporary ponds, road ditches and puddles) distributed in five localities of the El Tarf province, known for endemicity of fascioliasis. Snails were divided in 75 groups and DNA extraction was performed using Chelex® (Biorad, Nazareth Eke). Two primers were used, the first is specific for 124 bp DNA fragment of Fasciola sp and the second one represents the ITS-2 lymnaeids sequence (500-600 bp). The prevalence of the infection was estimated to be 46.66% for pools (35/75 were positive). The bursting out of the pools show that 75 snails were carriers of F. hepatica which gives an overall infection rate of about 10.74%. The results of snails infection according to their sizes showed significant differences in the studied size classes, thus snails of big sizes were the most infected. Based on these data, epidemiological implication of Multiplex PCR as a fully reliable technique to highlight high risks periods of fasciolosis will be of a great interest.

The zoonotic Onchocerca lupi and tick-transmitted filarioids of the genus Cercopithifilaria remain less well known due to the difficulties in accessing to skin samples as target tissues. Here, we proposed a molecular approach reliying on multiplex qPCR assays that allow the rapid identification of filarioids from canine blood, skin, and tick samples. This includes two newly developed duplex qPCR tests, the first one targeting filarial and C. grassii DNA (CanFil-C. grassii). and the second qPCR assay designed for the detection of Cercopithifilaria bainae and Cercopithifilaria sp. II DNAs (C. bainae-C.spII). The third one is a triplex TaqMan cox 1 assay targeting DNA of blood microfilariae (e.g., Dirofilaria immitis, Dirofilaria repens and Acanthocheilonema reconditum). The novel duplex qPCRs developed were validated in silico and by screening of known DNA collection. The qPCR assays were also used for screening the blood and tick samples of 72 dogs from Algeria. This allowed the identification of canine filariasis infection with 100% of specificity and 89.47% and 100% of sensitivity from naturally infected blood and tick samples, respectively. The prevalences of 26.39% for D. immitis and 5.56% for both D. repens and A. reconditum were reported in blood and tick samples. Cercopithifilaria DNAs were detected only in tick samples, with a prevalence of 4.17% and 5.56% for C. bainae and Cercopithifilaria sp. II, respectively. Co-infections were diagnosed in 6.94% and 13.89% of blood and tick samples, respectively. Whereas all samples were negative for C. grassii DNA. The use of engorged ticks instead of blood and skin samples could be an easier option for the surveillance of all canine filarioids herein investigated. The multiplex qPCR assays herein validated were shown to be useful in the detection of filarial co-infections by overcoming sequencing of positive samples.

Leishmaniasis is among the world’s most neglected diseases. Dogs are the main reservoirs/hosts of Leishmania infantum, causative agent of both canine and human visceral leishmaniosis. Canine leishmaniasis (CanL) represents a public health problem as one of the most prevalent zoonotic diseases worldwide. Current therapeutics present drawbacks; thus, there is a need for more effective, safer, and cheaper drugs. The aim of this study was to evaluate and to compare the efficacy of oral administration of artesunate or meglumine antimoniate/allopurinol in dogs with clinical leishmaniasis. Forty-two dogs with naturally occurring clinical leishmaniasis were included in this open-label, simple randomized positive-control clinical field trial with 6 months of follow-up. Dogs received meglumine antimoniate 100 mg/kg/day and allopurinol 30 mg/kg/day for 28 days (control group, n = 26) or artesunate 25 mg/kg/day for 6 days (test group, n = 16). The animals were evaluated for their clinical evolution, parasite load (by qPCR) and humoral response at different time points: 0, 30, 90, and 180 days after treatment. Data analyses showed a significant improvement in both groups in clinical scores, parasitemia and antibody titers after treatment. Compared to the control group, the artesunate group showed significantly lower clinical score (P = 0.0001), lower parasitemia (P = 0.0001) and antibody titers after 6 months of follow-up. Compared to baseline values, a rapid, significant reduction (P < 0.012) in antibody levels, 2.28- versus 3.04-fold for the control versus artesunate groups, respectively, was observed 30 days after treatment. Antibody levels continued to decrease further in the artesunate group, where 58% of cases became seronegative at the 6-month follow-up. All qPCR-positive dogs were negative after treatment with artesunate, while 14.3% remained positive with the appearance of two new cases in the control group. Artesunate was well tolerated, and no side effects were recorded. Treatment failures were similar in both groups with 27.27% (6/22), including 18.18% (4/22) mortality in the control group, versus 26.66% (4/15), including 13.33% (2/15) mortality in the artesunate group. This is the first report showing the potential of artesunate in the treatment of dogs with clinical leishmaniasis. Artesunate showed higher efficacy than the current first-line treatment for CanL without any adverse effects. It could be a good alternative chemotherapy for CanL, and may be considered for further studies in human leishmaniases. Further clinical trials are needed to confirm these findings, to determine if there are relapses after treatment and if dogs remain infective to sandflies, to define the ideal therapeutic dosage and duration of treatment with artesunate., Author summary Canine leishmaniasis (CanL) is a fatal, zoonotic vector-borne disease caused by Leishmania infantum, a common pathogen for both humans and dogs. Most CanL therapeutics are toxic, expensive, or ineffective. Artemisinin and derivatives have recently demonstrated potent antileishmanial activity in vitro and in experimental models. In this study, dogs with clinical leishmaniasis were randomly included in one of the treatment groups: meglumine antimoniate/allopurinol (control) or artesunate (alternative). Dogs were followed up for 6 months for their clinical score, parasitemia and Leishmania antibody levels. Both groups showed improved clinical scores, parasitemia and antibody titers after treatment. After six months of follow-up, treatment success was very similar in both groups, and 72.73% (16/22) of the controls versus 73.34% (11/15) in the artesunate group had clinical improvement. All dogs initially seropositive by PCR became negative after artesunate treatment, while 14.3% remained positive with the appearance of new cases in the control group. Antibody titers decreased rapidly (from day 30) from baseline especially in the artesunate group, where 58% of the dogs converted to seronegative after 6 months. Artesunate could be a good alternative for treatment of leishmaniasis. Additional clinical trials are needed to obtain more data on this drug.

International audience; Dogs are competent reservoirs/hosts of several protozoan pathogens transmitted by blood-feeding arthropods. Throughout their long history of domestication, they have served as a link for the exchange of parasites among livestock, wildlife, and humans and therefore remain an important source of emerging and re-emerging diseases. In Algeria, while canine leishmaniosis (CanL) is well known to be endemic, no data are available on other vector-borne protozoans. Here, we investigate the occurrence and diversity of trypanosomes, piroplasms and Hepatozoon spp. and update the epidemiological status of CanL in dogs from Kabylia, northern Algeria. A total of 227 dogs from three regions of Kabylia were enrolled, including 77 dogs with clinical signs. Dogs were clinically examined and were tested for L. infantum antibodies using a Rapid Immuno-Migration (RIM™) and a quantitative indirect Immunofluorescence Antibody Test (IFAT). PCR screening and sequencing were performed for vector-borne protozoa. Sixty two percent (141/227) of dogs presented at least one infection, whereas 26% (59/227) were co-infected. L. infantum antibodies were detected in 35.7% (81/227) of dogs including 88.7% (68/77) of sick dogs. Molecular investigation revealed prevalence of: 6.6% (15/227), 13.2% (30/227), 41% (93/227) for Trypanosoma spp., B. vogeli and H. canis, respectively. T. evansi (3.1%) and potential new subspecies of T. congolense had been identified. Dog''s clinical status correlates positively with L. infantum antibody titers and the presence of co-infections. Susceptibility to CanL varied according to the dog's aptitude and guard dogs were more infected (51%) (P-value = .001). B. vogeli infection was more frequent in juveniles than adults (32% vs 9%, P-value < .001) and in females than males (21% vs 10%, P-value = .02). To the authors' knowledge, this is the first report on vector-borne protozoa infected dogs in Algeria. Current results are important not only for animal health, but also to avoid serious public health and livestock problems.

Transplantations of Omphiscola glabra from granite to marl, or vice versa, between farms known for cases of fasciolosis have shown differences in the maximum shell height of adult snails. To determine whether these differences were due to parasitism, soil geology, or a combination of both factors, four snail populations living on marl or granite were investigated over 12 months to specify the characteristics of egg-laying in spring, and to follow the shell growth of both snail generations. In both types of habitats, the number of egg-masses per adult snail and their size significantly decreased during the 7 weeks of snail egg-laying. During this period, each adult snail on marl laid a mean of 6.4 masses and 93.3 eggs. On granite, the mean values were 5.7 masses and 69.1 eggs, respectively. Two annual generations, the first in spring and the other in autumn, were noted in these habitats. The maximum shell height of adults was different: a mean of 19.8 and 20.5 mm on marl compared with 17.2 and 18.2 mm on granite. Soil geology thus plays a role in the egg-laying and shell growth of O. glabra .

The present work deals with the study of nanocomposites based on polystyrene (PS)/low-density polyethylene (LDPE) blend and an organophilic clay (Bentone 38 (B38)). Different PS/LDPE/B38 mixtures were prepared via melt intercalation process using a two-roll mixer and a single-screw extruder. Analysis of the nanocomposites by means of X-ray diffraction showed that the characteristic peak of the clay appears only at 3% wt. content, indicating an intercalated structure of PS/LDPE/3% B38 nanocomposite. The mechanical properties of the nanocomposites reflected the effect of the addition of the filler as well as the state of interfacial adhesion between the polymer blend matrix and the filler. The incorporation of the clay into PS/LDPE blend resulted in a relative increase (particularly at 0.5% wt.) of the stress at break and microhardness owing to the interfacial interactions developed between the PS/LDPE matrix and the clay and between the two blend phases. This is in good agreement with PS/LDPE/B38 nanocompo...

Fatigue failure caused by stress concentrations in tubular welded joints is observed in off shore platforms subjected to cyclic loading in corrosive marine environments. In some junctions, the stress concentration can induce a stress thirty times the nominal stress, and increase the risk of fatigue failure in tubular joints. Therefore, it is necessary to accurately assess the intensity of the stress concentrations to effectively deal with the problem of fatigue damage and lead to reliable tubular joints. This work aims to study the stress distribution and location of the "hot" spots in a Twelded tubular structure subjected to a combined loading of tension and bending (in-plane bending, out of plane bending and traction) to better simulate the actual loading.

Experimental infections of two South American lymnaeids (Lymnaea neotropica and L. viatrix var. ventricosa) with Paramphistomum daubneyi were carried out to determine if these snail species could sustain larval development of this digenean and, if so, to specify their potential for cercarial production. A French population of Galba truncatula infected and raised according to the same protocol served as controls. In both experiments, prevalence of P. daubneyi infections in snails did not significantly differ from each other. In snail groups evaluated for cercarial shedding (first experiment), a significantly lower number of shed cercariae was noted for L. neotropica, while those from G. truncatula and L. v. ventricosa did not differ significantly from each other. Dissection of infected snails at day 65 post-exposure at 20°C (second experiment) found significantly lower burdens of P. daubneyi rediae and cercariae in the bodies of L. neotropica than in those of G. truncatula and L. v. ventricosa. Compared to total cercarial production observed in dissected snails, the percentage of cercariae which exited from snails was 75.6% for G. truncatula, 21.6% for L. neotropica, and 91.4% for L. v. ventricosa. This last species seems to be a good candidate for metacercarial production of P. daubneyi., Des infestations expérimentales de deux limnées sud-américaines (Lymnaea neotropica et L. viatrix var. ventricosa) avec Paramphistomum daubneyi ont été réalisées pour déterminer si ces espèces peuvent assurer le développement larvaire de ce Digène et, dans l’affirmative, pour préciser leur potentiel dans la production cercarienne. Les témoins sont constitués par une population française de Galba truncatula infestée et élevée selon le même protocole. Dans les deux expériences, les prévalences de l’infestation par P. daubneyi chez les mollusques sont proches les unes des autres. Chez les groupes suivis pour les émissions cercariennes (première expérience), le nombre de cercaires émises est significativement plus faible chez L. neotropica, tandis que les chiffres notés chez G. truncatula et L. v. ventricosa ne présentent pas de différence significative. Si les mollusques infestés sont disséqués au 65ème jour post-exposition à 20 °C (seconde expérience), les charges rédienne et cercarienne trouvées dans le corps des L. neotropica sont significativement plus faibles que celles notées chez G. truncatula et L. v. ventricosa. Par rapport à la production cercarienne totale chez les mollusques disséqués, le pourcentage de cercaires qui sont émises est de 75,6 % chez G. truncatula, 21,6 % chez L. neotropica et de 91,4 % chez L. v. ventricosa. Cette dernière espèce semble être un bon candidat pour la production métacercarienne de P. daubneyi., Centro de Diagnóstico e Investigaciones Veterinarias

Main Cattle Helminthosis: Epidemiological Investigation at Two Slaughters in the Area of El Tarf Algeria. From July 2010 to December 2011, an epidemiological survey on the main cattle helminthosis was conducted and involved a total of 821 cattle slaughtered at the abattoirs of Ain El Assel and Bouteldja. The results indicate that fasciolosis, hydatidosis and oesophagostomosis dominate with prevalences of 52.4%, 30.9% and 31.3% respectively. Coexist with these pathologies: paramphistomosis, haemonchosis, dictyocaulosis and monieziosis with prevalences of 19.2%, 17%, 15.4% and 11.1% respectively. Overall, the intensity of these parasitic entities is low. The origin of cattle does not affect significantly the prevalence of these pathologies (p≥ 0.05). However it is noted that Ain El Assel and Bouteldja are the most affected areas. Females and cattle over 5 years are the most infested, except for oesophagostomosis where young males (1-3 years) seem the most infested. In addition, all entities are observed throughout the year except for haemonchosis and monieziosis which disappear in December, dictyocaulosis which is absent in January and paramphistomosis which is not observed in January and February.

Parasitological investigations on ruminal paramphistomosis were carried out in 2033 cattle over a 14-month period in three Algerian slaughterhouses to determine the prevalence and intensity of this disease. The prevalence of infection varied from different slaughterhouses (1.2% at El Khroub, 7.5% at Ferdjioua and 12.1% at Jijel). The worm burden was significantly higher in cattle from El Khroub than for those slaughtered in the other two sites (a mean of 984.1 parasites compared with 87.5 and 140.7 at Jijel and Ferdjioua, respectively). No significant correlation between prevalence, intensity of infection and age of cattle was noted. Overall, females were significantly more infected than males, whereas the sex of animals was independent of worm burdens recovered in slaughtered cattle. The climatic conditions of provinces in which the slaughterhouses were located (a more temperate climate for Jijel and semiarid conditions for the other two provinces) may partly explain variations noted in prevalence and intensity of infection. The present results will contribute to our understanding of the epidemiology of Paramphistomum daubneyi infections in north-eastern Algeria.

A retrospective study on differentLymnaea glabrasamples collected from central France between 1993 and 2010 was carried out to determine the prevalence of natural co-infections withCalicophoron daubneyiandFasciola hepatica, and to specify the composition of redial burdens. Experimental infections ofL. glabraperformed during the same period of time were also analysed to study metacercarial production of each digenean in co-infected snails. Controls were naturally or experimentally co-infectedGalba truncatula. In natural co-infections, prevalence was 0.7% inL. glabra(186/25,128) and 0.4% inG. truncatula(137/31,345). Low redial burdens were found in these snails, withF. hepaticarediae significantly more numerous inL. glabrathan inG. truncatula(7.5 per snail instead of 5.2). In contrast, the total numbers ofC. daubneyirediae in both lymnaeids were close to each other (4.3 and 3.0 rediae, respectively). In experimentally co-infected groups, prevalence was greater inG. truncatulathan in the other lymnaeid (6.3% instead of 3.0%). Significantly shorter patent periods and lower metacercarial production for each digenean were noted inL. glabrathan inG. truncatula.However, in both lymnaeids, the two types of cercariae were released during the same shedding waves and several peaks during the patent period were synchronous. In spite of a greater shell height forL. glabra, metacercarial production of both digeneans in co-infected snails was lower than that inG. truncatula, thus indicating a still incomplete adaptation between these FrenchL. glabraand both parasites.

Colloque avec actes et comité de lecture. Internationale.; International audience; Le comportement tribologique, du pion en matériau paramagnétique (aluminium), glissant sur un disque tournant en matériau ferromagnétique (acier XC48), en présence du champ magnétique alternatif extérieurement appliqué, avec passage du courant électrique continu ont été étudié. Les essais ont été réalisés sur un tribomètre, type pion-disque. En effet, la caractérisation structurale des surfaces en contact, des oxydes et des débris d'usure, par diffraction des rayons X (angle θ -2 θ), a montré l'effet marqué du champ magnétique sur l'activation de la surface de contact du pion en matériau non ferromagnétique. L'absence du champ magnétique engendre un changement du mode d'usure, et on assiste à une transition du mode doux (usure par oxydation) à un mode abrasif sévère.