Neospora caninum is a protozoan parasite of animals. Until 1988, it was misidentified as Toxoplasma gondii. Since its first recognition in dogs in 1984 and the description of the new genus and species Neospora caninum in 1988, neosporosis has emerged as a serious disease of cattle and dogs worldwide. Abortions and neonatal mortality are a major problem in livestock operations, and neosporosis is a major cause of abortion in cattle. Although antibodies to N. caninum have been reported, the parasite has not been detected in human tissues. Thus, the zoonotic potential is uncertain. This review is focused mainly on the epidemiology and control of neosporosis in cattle, but worldwide seroprevalences of N. caninum in animals and humans are tabulated. The role of wildlife in the life cycle of N. caninum and strategies for the control of neosporosis in cattle are discussed.

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Epidemiology and Control of Neosporosis and Neospora caninum

Coxiella burnetii is the agent of Q fever, or ``query fever,'' a zoonosis first described in Australia in 1937. Since this first description, knowledge about this pathogen and its associated infections has increased dramatically. We review here all the progress made over the last 20 years on this topic. C. burnetii is classically a strict intracellular, Gram-negative bacterium. However, a major step in the characterization of this pathogen was achieved by the establishment of its axenic culture. C. burnetii infects a wide range of animals, from arthropods to humans. The genetic determinants of virulence are now better known, thanks to the achievement of determining the genome sequences of several strains of this species and comparative genomic analyses. Q fever can be found worldwide, but the epidemiological features of this disease vary according to the geographic area considered, including situations where it is endemic or hyperendemic, and the occurrence of large epidemic outbreaks. In recent years, a major breakthrough in the understanding of the natural history of human infection with C. burnetii was the breaking of the old dichotomy between ``acute'' and ``chronic'' Q fever. The clinical presentation of C. burnetii infection depends on both the virulence of the infecting C. burnetii strain and specific risks factors in the infected patient. Moreover, no persistent infection can exist without a focus of infection. This paradigm change should allow better diagnosis and management of primary infection and long-term complications in patients with C. burnetii infection.

https://hal.archives-ouvertes.fr/hal-01496178/document

From Q Fever to Coxiella burnetii Infection: a Paradigm Change.

Neosporosis in animals--the last five years.

In the last few years, the detection of free radical damage and the body's defences against it have become increasingly important in clinical medicine as a complementary tool in the evaluation of metabolic status. The aim of this study was to evaluate, under field conditions, the anti-oxidant status of healthy cows during late pregnancy and lactation onset using two parameters: (1) plasma levels of malondialdehyde (MDA), a degradation product of lipid peroxidation, and (2) total antioxidant status (TAS). Results were compared with those obtained in another group of cows with lesser metabolic demands. We also investigated possible relationships between antioxidant status markers and other relevant blood parameters. Our results confirmed the characteristic metabolic changes associated with late pregnancy and early lactation. MDA and TAS provided an accurate reflection of the internal physiological status of the animal. The data indicated increased lipid peroxidation around parturition, but with wide individual variations that may be attributable not only to the physiological stage but also to unknown factors that will have to be further considered in future studies.

Oxidative status during late pregnancy and early lactation in dairy cows.

Low density lipoproteins extracted from hen egg yolk by an easy method: cryoprotective effect on frozen-thawed bull semen.

Bull semen in vitro fertility after cryopreservation using egg yolk LDL: a comparison with Optidyl®, a commercial egg yolk extender

Effect of the association of IGF-I, IGF-II, bFGF, TGF-β1, GM-CSF, and LIF on the development of bovine embryos produced in vitro

The success of artificial insemination with frozen semen implies the reduction of the deleterious effects on the cells induced by this technique. These effects can occur as early as during the first dilution in an extender, as well as at any step, during or after the freezing process. In this work, we have compared the modifications induced by Triladyl, low density lipoproteins (LDL) and Biociphos extenders, after dilution and cooling to 4 8C for 1, 4 and 24 h. Alterations in the cell structures were visualized by electron microscopy (EM). More than 80% of spermatozoa were injured after incubation for 4 h in Triladyl, while 3% and 47% were counted in LDL and Biociphos respectively. This latter extender was deleterious to cell membrane integrity after incubation for 4 h or longer. The ultrastructure of frozen spermatozoa was studied by EM of cryofixed-cryosubstituted samples obtained from regular 0.5 ml French straws frozen using our usual protocol. The main differences between samples concerned the size and appearance of the frozen extender veins, while very few cell defects were found to be added by the freezing process at any depth in the straws. After thawing, semen motility was twofold higher (P < 0.05) in Biociphos (64%) and LDL (61%) than in Triladyl (32%) and the cells were less altered in LDL. We concluded that the LDL extender offers a better protection for storage of frozen spermatozoa, and can probably also be used for the preservation of fresh semen for short periods.

/pdf/modifications-of-bull-spermatozoa-induced-by-three-extenders-59v5be2eiz.pdf

Modifications of bull spermatozoa induced by three extenders: Biociphos, low density lipoprotein and Triladyl, before, during and after freezing and thawing

Summary

The purpose of this study was to evaluate the exact age when the equine embryo reaches the uterus. The time of ovulation was determined by hourly ultrasound examinations starting 32 h after an injection of crude equine pituitary gonadotrophin or human chorionic gonadotrophin, or after the first of 4 injections of buserelin. Nonsurgical uterine flushings were carried out 144 h (Day 6), 156 h (Day 6.5) or 168 h (Day 7) after ovulation. Induction of ovulation was attempted in 101 oestrous cycles and 61 of 101 mares (60.4%) ovulated 32–44 h post injection. Sixty embryo collections were performed which yielded: 0/20 embryos at 144 h, 9/17 embryos (53%) at 156 h and 12/23 embryos (52%) at 168 h. The mean (± s.e.m.) diameter of the embryo was significantly greater (P < 0.01) at Day 7 (244 ± 15 μm) than at Day 6.5 (186 ± 9.1 μm), and variability in size was observed among embryos collected from the same mare after synchronous natural multiple ovulations.



These results suggest that; i) horse embryos enter the uterus between 144 and 156 h after ovulation, and ii) the time interval between ovulation and fertilisation in mares is inconsistent and/or embryonic development rate may differ between individual embryos.

Daniel Tainturier

Papers

Low density lipoproteins extracted from hen egg yolk by an easy method: cryoprotective effect on frozen-thawed bull semen.

Bull semen in vitro fertility after cryopreservation using egg yolk LDL: a comparison with Optidyl®, a commercial egg yolk extender

Effect of the association of IGF-I, IGF-II, bFGF, TGF-β1, GM-CSF, and LIF on the development of bovine embryos produced in vitro

Modifications of bull spermatozoa induced by three extenders: Biociphos, low density lipoprotein and Triladyl, before, during and after freezing and thawing

Success rates when attempting to nonsurgically collect equine embryos at 144, 156 or 168 hours after ovulation.