ANAPLASMA OVIS PDF

Katherine M. The development of Anaplasma ovis was studied in Dermacentor andersoni males transferred from infected to susceptible sheep. Laboratory-reared male D. The ticks were removed and held at room temperature in a humidity chamber for 6 d, after which they were allowed to feed on five susceptible sheep for 1, 3, 5, 7, or 9 d.

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Metrics details. Anaplasma ovis is a major cause of small ruminant anaplasmosis, a tick-borne disease mainly affecting small ruminants in tropical and subtropical regions of the world. Due to health and production problems in dairy goat flocks in Corsica, France, and the demonstration of A.

The aim of the survey was to determine the prevalence and geographical distribution of A. In addition, the genetic diversity of A. Blood and faecal samples were collected in 55 clinically healthy flocks 10 goats per flock for A. Ticks were collected, identified and processed for A.

A high prevalence of A. No relationship was found between A. Positive A. Sequence and phylogenetic analysis of these genes confirmed the detection of A. The strain COR1 was the most represented, corresponding to The results showed a relatively high genetic diversity of A. Bacteria of the genus Anaplasma Rickettsiales: Anaplasmataceae are obligate intracellular microorganisms including important human e. These pathogens are mainly transmitted by tick bites, though other modes of transmission have been reported such as hematophagous insect bites and exposure to blood-contaminated fomites [ 1 , 2 ].

Anaplasma ovis is distributed worldwide and is considered as the most frequent cause of small ruminant anaplasmosis but seems to be less pathogenic than other Anaplasma species, causing only subclinical infections with a low grade fever [ 3 ]. The bacterium may cause a persistent infection and, in some instances, clinical cases related to haemolytic anaemia may be seen with pallor and icterus, but without haemoglobinuria. The general clinical signs of A.

Outbreaks of acute disease are rare and occur mostly under major stress conditions e. Additionally, as for other Anaplasma spp. Genetic diversity of tick-borne bacteria resulting in novel strains can be associated with changes in pathogenicity, virulence, shift in host range, prevalence and enhancement of the transmission [ 7 , 8 , 9 , 10 , 11 ].

High genetic diversity of A. Assessment of genetic variability and strain diversity might therefore be crucial to understanding the epidemiology of anaplasmosis and to implementing control measures. The economic significance of A. However, subclinical disease and the natural resistance acquired by autochthonous A.

Several wild animal species can be infected by A. There are numerous reports of high A. Corsica is an island where small ruminant breeding represents an important economic activity.

Sheep and goat production is the third most important agricultural activity of the island [ 22 ]. In September , an outbreak of bluetongue virus genotype 1 BTV-1 was reported in sheep and goat in southern Corsica and the virus spread across the island in early [ 24 ].

Meanwhile, health and production problems were declared by several dairy goat farmers throughout the island during the spring of , including emaciation and a drop in or even drying up of milk production, problems that did not seem to be due to BTV1. The main results indicated high levels of GIN egg excretion and a high prevalence of A.

Due to the controversial clinical impact of A. Thus, the objectives of the present survey were first to determine the prevalence of A. Goat farms participating in the present survey were selected on a convenient basis according to geographical location to represent the breadth of the island.

Fifty-five breeders volunteered to participate in this study: 32 from Haute-Corse and 23 from Corse-du-Sud counties Fig. No particular health problems were reported in the selected flocks at the time of the survey. The field survey was performed between April and June This period of time was chosen as it fitted with the maximal level of tick infestation of ruminants in Corsica [ 25 ]. Ten goats were randomly selected from each of the 55 herds, corresponding to samples in total.

To minimize a possible influence of age on the final within-flock outcome, the age of sampled goats was between 2. Blood samples were collected from the jugular vein of goats in plain tubes containing EDTA. Individual faecal samples were collected from rectum.

Ticks were collected from each goat mainly around the perineum and udder. All ticks were identified under a dissecting microscope according to the keys provided in [ 26 ]. For each farm, an equal part of the 10 individual faeces 2 g per goat was mixed to give a pooled faecal sample [ 28 ].

The faecal egg count FEC of gastrointestinal nematode eggs expressed as eggs per gram of faeces, epg was assessed from the pooled sample with the McMaster technique according to Raynaud [ 29 ]. Results were expressed as positive or negative. Doubtful results were considered as negative. Primer properties were further analysed using OligoAnalyzer [ 34 ]. We attempted to amplify fragments of gltA and msp4 genes in the goat samples positive to A.

No tick sample was selected for sequencing. Amplicons were deposited on 1. If in addition to the band of the expected size, several bands were observed, the band of the expected size was excised from the gel and purified using GeneJET Gel Extraction Kit Thermo Scientific. The and samples positive for gltA and msp4 were sent for sequencing and and sequences, respectively, were obtained. For msp4 , homologous sequences of different species belonging to the genus Anaplasma were retrieved from GenBank as follows: A.

Sequences were translated into proteins using the ExPASy translate tool [ 35 ]. For strain analysis, msp4 nucleotide and MSP4 protein sequences belonging to A. The maximum likelihood method, implemented in MEGA, was used to obtain the best tree topologies. Reliability of internal branches was assessed using the bootstrapping method with bootstrap replicates [ 39 ].

Within-flock prevalence was calculated as the ratio of positive animals on sampled animals in a given flock. Alpha was set at 0. A principal components analysis PCA was performed with R Studio [ 41 ] using the following matrix: the rows were the 55 flocks and columns were the corresponding values for A. The variables were represented on the principal plane.

The nearer the variables were located to the correlation circle, the better they were represented in the plane. The relative position of the variables on the plane corresponded to either a positive near variables , a negative variables diagonally opposed on the plane , or no association variables at a right angle.

The 55 dairy goat flocks were distributed on the whole area of the island, except for the central mountain chain, at a mean altitude of m range: 19— m Fig. At the individual level, the mean haematocrit was The individual seroprevalence of PTB was 9. Pooled faecal egg counts in the flocks ranged between 0— epg with an average of epg. The individual prevalence of A. The A. Similar associations were observed for flock prevalence with altitude and breeds. Anaplasma ovis prevalence in 55 goat flocks of Corsica.

The prevalence of A. Furthermore, no significant correlation was seen at flock level between within-flock prevalence of A. Results of the principal components analysis using A. However, a close association was found between GIN and anaemia particularly on the 1st axis. Principal components analysis to test relation between Anaplasma ovis infection, anaemia and other health indicators.

Relationships between number of A. Principal components analysis PCA variables are located on the main plane defined by the 1st and 2nd axis and circle of correlation. Ticks were found in the whole area of the survey. Zero to 27 ticks were observed from each goat and at least one tick was recorded on a goat in No significant relationship was observed between A.

Anaplasma ovis DNA was detected in Tick positive samples were not selected for sequencing. From the positive goat samples, we attempted to amplify fragments of gltA and msp4 genes for further sequence and phylogenetic analysis. Using the primers shown in Table 1 for a qualitative PCR assay, Among these positive samples, 86 From the gltA- positive and msp4- positive samples, Species classification based on real-time and qualitative PCR assays was confirmed by sequencing.

All amplified gltA sequences formed a unique clade with an A. Similar results were obtained when msp4 sequences were used to build the phylogenetic tree. All amplified msp4 sequences clustered with the A. Phylogenetic analysis of Anaplasma ovis gltA and msp4 nucleotide sequences identified in Corsica. Maximum likelihood phylogenetic trees were inferred using gltA and msp4 nucleotide sequences of A.

All gltA and msp4 nucleotide sequences of Corsica formed a unique clade with A. The clades containing A. Reliability of internal branches was assessed using the bootstrapping method replicates.

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Anaplasma ovis

Metrics details. Anaplasma ovis is a major cause of small ruminant anaplasmosis, a tick-borne disease mainly affecting small ruminants in tropical and subtropical regions of the world. Due to health and production problems in dairy goat flocks in Corsica, France, and the demonstration of A. The aim of the survey was to determine the prevalence and geographical distribution of A. In addition, the genetic diversity of A. Blood and faecal samples were collected in 55 clinically healthy flocks 10 goats per flock for A. Ticks were collected, identified and processed for A.

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To the Editor: Anaplasmosis is a disease caused by bacteria of the genus Anaplasma. Anaplasma spp. We report infection of a human with a strain of Anaplasma sp. Physical examination showed hepatosplenomegaly and an enlarged lymph node. Initial laboratory examinations showed moderate anemia hemoglobin Blood samples were obtained from the patient at the time of admission and 7 days and 3 months later.

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The genus Anaplasma is made up of organisms characterized by small genomes that are undergoing reductive evolution. Anaplasma ovis , one of the seven recognized species in this genus, is an understudied pathogen of sheep and other ruminants. This tick-borne agent is thought to induce only mild clinical disease; however, small deficits may add to larger economic impacts due to the wide geographic distribution of this pathogen. In this report we present the first complete genome sequence for A. The metabolic potential is similar to other Anaplasma species. Anaplasma ovis has a small repertoire of surface proteins and transporters. Several novel genes are identified.

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