Summary
The Schmallenberg virus (SBV) has recently emerged in Europe, causing losses to the domestic livestock. A retrospective analysis of serodata was conducted in France for estimating ...seroprevalence of SBV among six wildlife species from 2011–2012 to 2013–2014, that is during the three vector seasons after the emergence of the SBV in France. Our objective was to quantify the exposure of wildlife to SBV and the potential protective effect of elevation such as previously observed for bluetongue. We also compared the spatiotemporal trends between domestic and wild animals at the level of the departments. We tested 2050 sera using competitive ELISA tests. Individual and population risk factors were further tested using general linear models among 1934 individuals. All populations but one exhibited positive results, seroprevalence up to 30% being observed for all species. The average seroprevalence did not differ between species but ranged from 0 to 90% according to the area and period, due to the dynamic pattern of infection. Seroprevalence was on average higher in the lowlands compared to areas located up to 800 m. Nevertheless, seroprevalence above 50% occurred in areas located up to 1500 m. Thus, contrary to what had been observed for bluetongue during the late 2000s in the same areas, SBV could spread to high altitudes and infect all the studied species. The spatial spread of SBV in wildlife did not fully match with SBV outbreaks reported in the domestic livestock. The mismatch was most obvious in mountainous areas where outbreaks in wildlife occurred on average one year after the peak of congenital cases in livestock. These results suggest a much larger spread and vector capacity for SBV than for bluetongue virus in natural areas. Potential consequences for wildlife dynamics are discussed.
Toxoplasma gondii isolates have been classified into 3 genetic types. Little is known about genotypes of
T. gondii isolates in wild animals in Europe. In this report, genotypes of
T. gondii isolates ...from wildlife in France are described. Sera from wildlife were tested for antibodies to
T. gondii with the modified agglutination test, and the hearts from animals with titers superior or equal to 1:6 were bioassayed individually in mice.
T.gondii was isolated from 9 of 14 seropositive red foxes (
Vulpes vulpes), 12 of 33 roe deer (
Capreolus capreolus), 1 of 4 deer (
Cervus elaphus), 1 of 7 mouflons (
Ovis gmelini musimon) and 1 of 2 common mallards (
Anas platyrhynchos). No isolate was obtained by bioassay in mice of 1 fallow deer (
Dama dama) and of 3 European brown hares (
Lepus europaeus). Genotyping of the 24 isolates using PCR-RFLP and microsatellite markers indicated that all were type II and none of these
Toxoplasma isolates was virulent for mice.
The Scalloped wings (Scl) gene of the Australian sheep blowfly, Lucilia cuprina, is shown to be the homologue of the Drosophila melanogaster Notch gene by comparison at the DNA sequence and genetic ...levels. A L. cuprina genomic fragment, which shows strong identity with the Notch (N) gene at the molecular level, hybridizes to the location of the Scl gene on polytene chromosomes. The two genes are functionally homologous; the dominant and recessive Notch-like phenotypes produced by mutations in the Scl gene allow these alleles to be classed as N-like or Abruptex-like. The Scl gene is under investigation as a candidate for the fitness and asymmetry Modifier (M) of diazinon resistance. We show that M affects the penetrance of wing and bristle phenotypes associated with two Scl alleles in a manner consistent with the M being an allele of Scl. In addition, we report a phenotypic interaction between the diazinon-resistance mutation, Rop-1, and the same alleles of Scl. We propose that the product of Rop-1, an esterase, may be involved in cell adhesion in developmental processes involving the Scl gene product.
The mechanisms responsible for the fine tuning of development, where the wildtype phenotype is reproduced with high fidelity, are not well understood. The difficulty in approaching this problem is ...the identification of mutant phenotypes indicative of a defect in these fine-tuning control mechanisms. Evolutionary biologists have used asymmetry as a measure of developmental homeostasis. The rationale for this was that, since the same genome controls the development of the left and right sides of a bilaterally symmetrical organism, departures from symmetry can be used to measure genetic or environmental perturbations. This paper examines the relationship between asymmetry and resistance to organophosphorous insecticides in the Australian sheep blowfly, Lucilia cuprina. A resistance gene, Rop-1, which encodes a carboxylesterase enzyme, also confers a significant increase in asymmetry. Continued exposure of resistant populations to insecticide has selected a dominant suppressor of the asymmetry phenotype. Genetic evidence indicates that the modifier is the L. cuprina Notch homologue.
Wildlife reservoirs of infectious diseases raise major management issues. In Europe, brucellosis has been eradicated in domestic ruminants from most countries and wild ruminants have not been ...considered important reservoirs so far. However, a high prevalence of
infection has been recently identified in a French population of Alpine ibex (
), after the emergence of brucellosis was confirmed in a dairy cattle farm and two human cases. This situation raised the need to identify the factors driving the persistence of
infection at high prevalence levels in this ibex population. In the present paper, we studied the shedding pattern of
in ibex from Bargy Massif, French Alps. Bacteriological examinations (1-15 tissues/samples per individual) were performed on 88 seropositive, supposedly infected and euthanized individuals. Among them, 51 (58%) showed at least one positive culture, including 45 ibex with at least one
isolation from a urogenital sample or a lymph node in the pelvic area (active infection in organs in the pelvic area). Among these 45 ibex, 26 (30% of the total number of necropsied animals) showed at least one positive culture for a urogenital organ and were considered as being at risk of shedding the bacteria at the time of capture. We observed significant heterogeneity between sex-and-age classes: seropositive females were most at risk to excrete
before the age of 5 years, possibly corresponding to abortion during the first pregnancy following infection such as reported in the domestic ruminants. The high shedding potential observed in young females may have contributed to the self-sustained maintenance of infection in this population, whereas males are supposed to play a role of transmission between spatial units through venereal transmission during mating. This heterogeneity in the shedding potential of seropositive individuals should be considered in the future to better evaluate management scenarios in this system as well as in others.
Thirty-five nucleotide polymorphisms were found in a 21.5-kbp region including the Est6 locus among 42 isoallelic lines extracted from a single natural population of Drosophila melanogaster. The ...heterozygosity per nucleotide pair was estimated to be 0.010 overall, but was lower in sequences hybridizing to transcripts than in those not hybridizing to transcripts. Eleven of 36 pairwise comparisons among the nine most common polymorphisms showed significant gametic disequilibrium. Four of these polymorphisms were also significantly associated with the major EST6-F/EST6-S allozyme polymorphism. Significant disequilibrium was generally restricted to polymorphisms less than 1-2 kbp apart. Previously reported measures of EST6 activity in virgin adult females proved not to be significantly associated with any of the six most common nucleotide polymorphisms located in the Est6 coding region or the 1.5 kbp immediately 5'. However, the 11 haplotypes for five of these polymorphisms that lie in the 1.5-kbp 5' region could explain about half of the previously reported variation among the lines for both EST6 activity and the amount of EST6 protein in virgin adult males. One particular polymorphism, for a RsaI site 530 bp 5' of the initiation codon, could explain 21% of the male activity variation among lines. This site is embedded in a large palindrome and we suggest that sequences including or close to this site may be involved in the regulation of EST6 synthesis in the ejaculatory duct of the adult male
We report heritable threefold differences in both larval and pupal esterase 6 activity among 17 isoallelic lines of D. melanogaster extracted from a natural population. The activity differences in ...the two stages are only weakly correlated with each other or with previously determined values for esterase 6 activity in adults of these lines. The pre-adult activity variation is also unrelated to polymorphisms among the lines for six esterase 6 allozymes and six restriction sites in a region encompassing the esterase 6 coding DNA and the first kbp of 5' flanking DNA. However, two insertions, of 8.0 and 6.8 kbp, located about 1.4 kbp 5' of the esterase 6 coding region are associated with low activity in larvae and, to a lesser extent, in pupae, albeit not in adults. Restriction mapping reveals similarity between the 8.0 kbp insert and the 7.4 kbp retrotransposon 17.6. The differences in larval activity among lines are positively correlated with fitness as assessed from assays of pre-adult viability and development time but no significant associations between pupal esterase 6 activity and these measures are detected. Some effects of esterase 6 allozyme differences are also found for viability and development time but these effects could be explained by linkage disequilibrium between the 8.0 kbp insert and the EST6-9 allozyme.
Previous studies have shown that the esterase 6 (EST6) enzyme of D. melanogaster is mainly produced in the sperm ejaculatory duct of the adult male and comparisons of wild-type males with laboratory ...null mutants have suggested that the enzyme plays a role in reproductive fitness. In this study we have compared 18 field-derived lines each isoallelic for Est6 for differences in five components of male reproductive fitness. No consistent fitness differences were found among lines differing in respect of the two major allozyme classes EST6-F and EST6-S, despite other evidence that these two classes are not selectively equivalent in the field. However, differences in reproductive fitness were found among lines differing in the minor mobility variants that segregate within EST6-F and EST6-S. A failure to distinguish among these minor forms may explain the discrepancies in previous studies on the effects of the major EST6 allozymes on reproductive fitness. The most significant associations we have found between EST6 and reproductive fitness were due to variation in EST6 activity levels. Male EST6 activity levels were found to be positively correlated with their time to first mating, negatively correlated with the numbers of eggs laid and progeny produced by their mates, and negatively correlated with the frequency with which their mates remate. We conclude that some EST6 variants differ in components of male reproductive fitness operative in laboratory cultures. However, the evidence for fitness differences is stronger for variants affecting the amount, rather than the structure of the enzyme, and the direction of the differences varies between some of the fitness components tested.
Eighty percent of rural dispensaries are run by the government and 19% by voluntary organisations that charge for some services. After the re-legalisation of the private health sector in 1991, ...private dispensaries are also emerging in villages. Privatisation is among the health reform policies of the country. Moreover, cost-sharing will be introduced at public dispensaries soon. Perception of 320 patients in the Coast Region of Tanzania on services delivered by the three health sectors has been investigated. Results show that patients are generally satisfied with the services and they would go back to the same dispensaries for treatment. Polydrug prescription was common in all sectors, while lack of prescribed drugs was a main complaint among public dispensaries patients. Voluntary dispensaries patients were less satisfied with long waiting time and with staff that did not give them enough information about the treatment. Currently, health service in public dispensaries is free but cost-sharing will be introduced soon. Most of voluntary and private dispensaries patients stated that the fees for service were moderate. The paper discusses the need for monitoring the implementation of cost sharing in public dispensaries to ensure equity in access to services by rural patients.
PDF
