Publications by authors named "Hanène Belkahia"

17 Publications

  • Page 1 of 1

Zoonotic Species in Small Ruminant Ticks From Tunisia.

Front Vet Sci 2021 26;8:676896. Epub 2021 May 26.

Service de Microbiologie et Immunologie, Ecole Nationale de Médecine Vétérinaire, University of Manouba, Sidi Thabet, Tunisia.

Tick-borne rickettsioses present a significant public health threat among emerging tick-borne diseases. In Tunisia, little is known about tick-borne pathogens. Therefore, the aim of this study was to investigate the presence of species in small ruminant ticks from Tunisia. Adult ticks ( = 694) were collected from goats and sheep in northern Tunisia. Obtained ticks were identified as ( = 434) and sensu lato ( = 260). Selected ticks ( = 666) were screened for the presence of spp. by PCR targeting a partial sequence of the gene followed by sequence analysis. Rickettsial DNA was detected in 122 (18.3%) tested tick samples. The infection rates in and s.l. ticks were 23.4 and 9.5%, respectively. The overall prevalence of rickettsial DNA was markedly higher in ticks collected from goats (23.2%) compared to those infesting sheep (7.9%). The detection of rickettsial DNA was significantly higher in ticks from the governorate of Beja (39.0%) than those from the governorate of Bizerte (13.9%). Two additional genes, the outer membrane protein A gene () and the citrate synthase gene (), were also targeted for further characterization of the detected species. Genotyping and phylogenetic analysis based on partial sequences ( = 106) of the three different genes revealed that positive ticks are infected with different isolates of two Spotted Fever Group (SFG) , namely, and , closely related to those infecting camels and associated ticks from Tunisia, and humans and small ruminant ticks from neighboring countries like Italy, France, and Spain.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fvets.2021.676896DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8187766PMC
May 2021

Molecular phylogeny and genetic diversity based on msp1a, groEL and gltA genes of Anaplasma ovis Tunisian isolates compared to available worldwide isolates and strains.

Ticks Tick Borne Dis 2020 09 30;11(5):101447. Epub 2020 Apr 30.

Service de Microbiologie et Immunologie, Ecole Nationale de Médecine Vétérinaire, Université de La Manouba, 2020 Sidi Thabet, Tunisia. Electronic address:

Anaplasma ovis, the causative agent of ovine anaplasmosis in tropical and subtropical countries, is a tick-borne obligatory intraerythrocytic bacterium of sheep, goats and wild ruminants. In Tunisia, data about the molecular phylogeny and the genetic diversity of A. ovis isolates are limited to the analysis of msp4 and groEL genes. The aim of this study was to genetic characterize 40 A. ovis isolates infecting 28 goats, 10 sheep, one camel and one Rhipicephalus turanicus tick located in different geographic regions of Tunisia on the basis of 3 partial genes (gltA, groEL and msp1a). Sequence analysis revealed 6 and 17 different genotypes in the partial gltA and groEL genes, respectively. Phylogenetic analysis revealed, as expected for the groEL gene, that sequences from small ruminants and their infesting ticks clustered separately from those isolated from camels. The analysis of amino-acid Msp1a sequences identified 18 novel genotypes of Msp1a repeats from 20 A. ovis isolates. These Msp1a repeats were highly variable with 33-47 amino-acids, and the number of repeats is one for 19 isolates infecting 18 goats and one R. turanicus tick, and 4 for a single isolate found in one sheep. Phylogenetic trees based on Msp1a partial sequences revealed that the N-terminal region of Msp1a protein appear to be relatively more informative phylogeographically compared to other markers especially according to countries. The presented data give a more detailed knowledge regarding the molecular phylogeny and the genetic diversity of A. ovis isolates occurring in different animal species and their associated ticks in Tunisia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ttbdis.2020.101447DOI Listing
September 2020

Molecular epidemiology of Anaplasma spp. related to A. phagocytophilum in Mediterranean small ruminants.

Acta Trop 2020 Feb 29;202:105286. Epub 2019 Nov 29.

Department of Veterinary Medicine, University of Sassari, Sassari, Italy; Mediterranean Center for Disease Control, University of Sassari, 07100 Sassari, Italy. Electronic address:

The genus Anaplasma currently comprises 6 bacterial species mostly pathogenic to animals and/or human, including the zoonotic species Anaplasma phagocytophilum, the causative agent of tick-borne fever (TBF) of ruminants, and of granulocytic anaplasmosis of horses, dogs and human. Recently, novel potentially non-pathogenic strains related to A. phagocytophilum have been identified in Japan, China, and Tunisia. This paper reports the identification, molecular typing, and evolutionary history of novel Anaplasma strains (A. phagocytophilum-like 1 and 2), related to but distinct from A. phagocytophilum in Mediterranean area of Europe and Africa. PCR-RFLP and phylogenetic analyses based on 16S rRNA provided evidence for the circulation of A. phagocytophilum-like 1 strains in Europe. Phylogeny based on groEL gene showed the inclusion of Sardinian and Tunisian A. phagocytophilum-like 1 strains in a unique clade distinct from, but related to that of Japanese strains. Results suggest that genetic diversity within the genus Anaplasma is much greater than expected and provide information useful for the development of specific and effective diagnostic and prophylactic tools.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.actatropica.2019.105286DOI Listing
February 2020

Computational selection of minimum length groESL operon required for Anaplasma species attribution and strain diversity analysis.

Mol Cell Probes 2019 12 25;48:101467. Epub 2019 Sep 25.

Service de Microbiologie et Immunologie, Ecole Nationale de Médecine Vétérinaire, Université de Manouba, 2020, Sidi Thabet, Tunisia. Electronic address:

Anaplasmosis is a tick-borne rickettsial disease caused by Anaplasma marginale, A. centrale, A. phagocytophilum, A. bovis, A. ovis and A. platys. Understanding the phylogenetic relations among these species is fundamental to perform an accurate identification and an informative intra-specific analysis. Heat shock groESL operon is frequently employed in phylogenetic analysis of Anaplasma species and, for the most cases, the use of partial sequences of this operon is randomly done without knowing the most appropriate regions to be used either in species attribution or in intra-specific diversity analysis. In this study, on the basis of all fully and nearly complete groESL sequences available in the GenBank, we firstly selected a minimum partial length sequence which allows species delineation and gives a similar topology to that found by analyzing the complete sequence. By using other in silico analyses, we obtained two minimal partial sequences that are the most interesting to describe intra-specific diversity within A. ovis and A. centrale. Our results raise concern on the use of randomly selected partial sequences of groESL operon employed for the detection and the characterization of Anaplasma species and provide additional background about minimum length groESL operon required for Anaplasma species attribution and strains diversity analysis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.mcp.2019.101467DOI Listing
December 2019

Molecular detection, genotyping and phylogeny of Anaplasma spp. in Rhipicephalus ticks from Tunisia.

Acta Trop 2019 Mar 21;191:38-49. Epub 2018 Dec 21.

Service de Microbiologie et Immunologie, Ecole Nationale de Médecine Vétérinaire, Univ. Manouba, 2020, Sidi Thabet, Tunisia. Electronic address:

In Tunisia, most of Anaplasma species and unclassified strains have been detected in several animals, but data on the occurrence of Anaplasma spp. in ticks are still lacking. In this study, we report the molecular evidence, genetic characterization and phylogeny of Anaplasma spp. in ticks collected from small ruminants. A total of 395 ticks (178 males and 179 females) were collected from sheep (n = 215) and goats (n = 180). Tick species were identified as 232 Rhipicephalus turanicus, 99 Rhipicephalus sanguineus sensu lato, 34 Rhipicephalus bursa and 30 Rhipicephalus annulatus. Overall infection rate of Anaplasma spp. was 5.6% (20/357 analyzed ticks). All positive ticks were collected from goats and found to be infected by A. ovis. R. turanicus is the most infected tick species by A. ovis (7.9%) followed by R. sanguineus s.l. (2.5%) with an absence of infection in R. bursa and R. annulatus. A. ovis prevalence rate varied significantly according to bioclimatic areas and geographic regions. GroEL typing and phylogenetic analysis revealed that these analyzed ticks are infected with various and novel strains of A. ovis. The use of PCR-RFLP method complemented with sequencing and phylogenetic analysis based on 16S rRNA gene confirm that one R. turanicus tick, positive to A. ovis, is co-infected with A. phagocytophilum-like 2 (0.3%). Specific A. phagocytophilum, A. phagocytophilum-like 1, A. marginale, A. centrale, A. bovis, and A. platys and related strains were not detected in any of the tested ticks. Present data expand knowledge about tick-borne bacteria present in ticks and further clarify the transmission cycles of these bacteria and their different elements in Tunisia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.actatropica.2018.12.034DOI Listing
March 2019

Genetic characterization of Anaplasma marginale strains from Tunisia using single and multiple gene typing reveals novel variants with an extensive genetic diversity.

Ticks Tick Borne Dis 2018 07 12;9(5):1275-1285. Epub 2018 May 12.

Service de Microbiologie et d'Immunologie, Ecole Nationale de Médecine Vétérinaire, Université de La Manouba, 2020 Sidi Thabet, Tunisie. Electronic address:

Anaplasma marginale, which is responsible for bovine anaplasmosis in tropical and subtropical regions, is a tick-borne obligatory intraerythrocytic bacterium of cattle and wild ruminants. In Tunisia, information about the genetic diversity and the phylogeny of A. marginale strains are limited to the msp4 gene analysis. The purpose of this study is to investigate A. marginale isolates infecting 16 cattle located in different bioclimatic areas of northern Tunisia with single gene analysis and multilocus sequence typing methods on the basis of seven partial genes (dnaA, ftsZ, groEL, lipA, secY, recA and sucB). The single gene analysis confirmed the presence of different and novel heterogenic A. marginale strains infecting cattle from the north of Tunisia. The concatenated sequence analysis showed a phylogeographical resolution at the global level and that most of the Tunisian sequence types (STs) formed a separate cluster from a South African isolate and from all New World isolates and strains. By combining the characteristics of each single locus with those of the multi-loci scheme, these results provide a more detailed understanding on the diversity and the evolution of Tunisian A. marginale strains.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ttbdis.2018.05.008DOI Listing
July 2018

Anaplasma spp. in North Africa: A review on molecular epidemiology, associated risk factors and genetic characteristics.

Ticks Tick Borne Dis 2018 03 3;9(3):543-555. Epub 2018 Feb 3.

Service de Microbiologie et d'Immunologie, Ecole Nationale de Médecine Vétérinaire, Université de La Manouba, Sidi Thabet, Tunisia.

The genus Anaplasma belonging to the Anaplasmataceae family (order Rickettsiales) comprises obligate intracellular Gram-negative bacteria of veterinary and public health importance. Six species and five types of strains genetically related are currently assigned to the genus Anaplasma including Anaplasma marginale, A. centrale, A. bovis, A. phagocytophilum, A. ovis and A. platys as classified species, and "A. capra", A. odocolei sp. nov., A. phagocytophilum-like 1 (Anaplasma sp.-Japan), A. phagocytophilum-like 2 (Anaplasma sp.-China) and A. platys-like (also named Candidatus Anaplasma camelii) as unclassified strains. Most of these Anaplasma species and strains have been molecularly identified in several animal and/or tick species in the north of Africa. The aim of this review is to summarize the current knowledge about molecular epidemiology, associated risk factors and genetic diversity of Anaplasma species and related strains infecting animals and/or their incriminated tick vectors in North Africa. All these data should be considered when establishing of common management and control programs for anaplasmosis infecting humans and different animal species in North African countries.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ttbdis.2018.01.003DOI Listing
March 2018

Spatio-temporal variations and genetic diversity of Anaplasma spp. in cattle from the North of Tunisia.

Vet Microbiol 2017 Sep 7;208:223-230. Epub 2017 Aug 7.

Service de Microbiologie et Immunologie, Ecole Nationale de Médecine Vétérinaire, Université de La Manouba, 2020 Sidi Thabet, Tunisie. Electronic address:

In cattle, anaplasmosis is a tick-borne rickettsial disease caused by Anaplasma marginale, A. centrale, A. phagocytophilum, and A. bovis. To date, no information concerning the seasonal dynamics of single and/or mixed infections by different Anaplasma species in bovines are available in Tunisia. In this work, a total of 1035 blood bovine samples were collected in spring (n=367), summer (n=248), autumn (n=244) and winter (n=176) from five different governorates belonging to three bioclimatic zones from the North of Tunisia. Molecular survey of A. marginale, A. centrale and A. bovis in cattle showed that average prevalence rates were 4.7% (minimum 4.1% in autumn and maximum 5.6% in summer), 7% (minimum 3.9% in winter and maximum 10.7% in autumn) and 4.9% (minimum 2.7% in spring and maximum 7.3% in summer), respectively. A. phagocytophilum was not detected in all investigated cattle. Seasonal variations of Anaplasma spp. infection and co-infection rates in overall and/or according to each bioclimatic area were recorded. Molecular characterization of A. marginale msp4 gene indicated a high sequence homology of revealed strains with A. marginale sequences from African countries. Alignment of 16S rRNA A. centrale sequences showed that Tunisian strains were identical to the vaccine strain from several sub-Saharan African and European countries. The comparison of the 16S rRNA sequences of A. bovis variants showed a perfect homology between Tunisian variants isolated from cattle, goats and sheep. These present data are essential to estimate the risk of bovine anaplasmosis in order to develop integrated control policies against multi-species pathogen communities, infecting humans and different animal species, in the country.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetmic.2017.08.004DOI Listing
September 2017

Seasonal dynamics, spatial distribution and genetic analysis of Anaplasma species infecting small ruminants from Northern Tunisia.

Infect Genet Evol 2017 10 17;54:66-73. Epub 2017 Jun 17.

Service de Microbiologie et Immunologie, Ecole Nationale de Médecine Vétérinaire, Université de La Manouba, 2020 Sidi Thabet, Tunisia. Electronic address:

To date, there have been no reports on seasonal variations of Anaplasma spp. in South Mediterranean small ruminants. In this longitudinal field study, single and mixed Anaplasma spp. infections in small ruminants from five different governorates belonging to three bioclimatic zones from the North of Tunisia were evaluated according to seasons. A total of 1685 blood small ruminant samples were collected in spring (355 sheep and 241 goats), summer (249 sheep and 202 goats), autumn (236 sheep and 186 goats) and winter (132 sheep and 84 goats). Molecular survey of A. ovis and A. bovis showed that average prevalence rates were 35.6% (minimum 30.7% in spring and maximum 43.6% in autumn) and 7.4% (minimum 0.9% in spring and maximum 18.1% in summer), respectively, in sheep, and 46% (minimum 21.7% in summer and maximum 65.5% in winter) and 10.1% (minimum 2.2% in autumn and maximum 23.8% in summer), respectively, in goats. A. phagocytophilum was not detected in all investigated animals. The infection profiles of A. ovis and A. bovis show that anaplasmosis caused by A. ovis is endemic in small ruminants from all investigated bioclimatic areas during the four seasons but conversely, A. bovis infection is highly intensified only in the summer. A. ovis and A. bovis infections were validated by sequencing. The comparison of the 16S rRNA sequences of A. bovis variants showed 100% identity between Tunisian variants isolated from goats, sheep and cattle. The analysis of A. ovis msp4 sequences revealed two different genetic variants previously described in Italy. This is the first survey outlining seasonal dynamics of Anaplasma spp. infections in Tunisian small ruminants. This situation should to be taken into account if anaplasmosis control programs in these domesticated animals are envisaged.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.meegid.2017.06.016DOI Listing
October 2017

Anaplasma platys-like strains in ruminants from Tunisia.

Infect Genet Evol 2017 04 24;49:226-233. Epub 2017 Jan 24.

Laboratoire de Microbiologie, Ecole Nationale de Médecine Vétérinaire, Institution de la Recherche et de l'Enseignement Supérieur Agricoles, Université de La Manouba, Sidi Thabet, Tunisia. Electronic address:

Molecular diagnosis of Anaplasma platys and related strains (A. platys-like) in carnivores and ruminants is challenging due to co-infections with cross-reacting strains, and require post-amplification sequencing of the hemi-nested PCR products traditionally generated by targeting the groEL gene. In this study, a Restriction Enzyme Fragment Length Polymorphism (RFLP) assay coupled to hemi-nested groEL PCR was developed to discriminate among A. platys and genetically related strains. This novel approach was used for investigating A. platys-like infection in 963 domesticated ruminants (241 goats, 355 sheep, and 367 cattle) from 22 delegations located in North Tunisia. Overall prevalence rates of A. platys-like were 22.8, 11, and 3.5% in goats, sheep, and cattle, respectively. Alignment, identity comparison, and phylogenetic analysis of the groEL sequence variants obtained in this study confirmed RFLP data suggesting that Tunisian ruminants are infected by novel unclassified Anaplasma strains genetically related to A. platys. Compared to sequencing, RFLP assay allows fast detection of A. platys and A. platys-like pathogens in the same sample and has a potential value especially when screening ticks, cats and ruminants, which can be a common host for these two bacteria. This newly developed molecular technique would provide valuable molecular tool for epidemiological studies related to A. platys as well as remove concern over specificity of serological and molecular methods routinely used to identify diverse Anaplasma strains and species in wild and domestic ruminants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.meegid.2017.01.023DOI Listing
April 2017

Molecular typing and diagnosis of Anaplasma spp. closely related to Anaplasma phagocytophilum in ruminants from Tunisia.

Ticks Tick Borne Dis 2017 03 16;8(3):412-422. Epub 2017 Jan 16.

Laboratoire de Microbiologie, Ecole Nationale de Médecine Vétérinaire, Institution de la Recherche et de l'Enseignement Supérieur Agricoles, Université de La Manouba, Sidi Thabet, Tunisia. Electronic address:

Accurate diagnosis of animal and zoonotic diseases, such as granulocytic anaplasmosis, is crucial to estimate risk during control programs. In this study, 16S rRNA nested PCR and RFLP assay were combined to investigate the presence of Anaplasma phagocytophilum and genetically related strains (namely A. phagocytophilum-like 1 and 2) in 936 Tunisian ruminants. By using this method, A. phagocytophilum was not detected in any of the tested animals, while A. phagocytophilum-like 1 and A. phagocytophilum-like 2 were detected at variable prevalence rates in sheep, goats and cattle at coinfection rates respectively of 3.9, 2.5 and 0.5%. Sequence analysis validated RFLP data, and confirmed the co-occurrence of two potentially novel species closely related to A. phagocytophilum in Tunisian ruminants. Phylogeny indicated the presence of genetic variants shared by different ruminant species for each type of A. phagocytophilum-like strains. Results raise concern on the use and interpretation of indirect and direct tests traditionally employed for detecting pathogenic A. phagocytophilum strains in ruminants and in other vertebrates' species, and provide additional background to improve classification of bacterial species closely related to A. phagocytophilum, and to reconstruct their evolutionary history.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ttbdis.2017.01.005DOI Listing
March 2017

First molecular evidence of [i]Borrelia burgdorferi[/i] sensu lato in goats, sheep, cattle and camels in Tunisia.

Ann Agric Environ Med 2016 Sep;23(3):442-7

Laboratoire de Microbiologie, Ecole Nationale de Médecine Vétérinaire, Université de La Manouba, Tunisia.

Borrelia burgdorferi sensu lato (s.l.) are tick-transmitted spirochaetes of veterinary and human importance. Molecular epidemiology data on ruminants are still lacking in most countries of the world. Therefore, the aim of this study was to estimate the rate of B. burgdorferi s.l. infection in ruminants from Tunisia. A total of 1,021 ruminants (303 goats, 260 sheep, 232 cattle and 226 camels) from different bioclimatic areas in Tunisia were investigated for the presence of B. burgdorferi s.l. DNA in blood by real time PCR. Prevalence rates were 30.4% (92/303) in goats, 6.2% (16/260) in sheep, 1.3% (3/232) in cattle, and 1.8% (4/226) in camels. Only tick species belonging to Rhipicephalus and Hyalomma genera were found on the investigated animals. In small ruminants, the prevalence of B. burgdorferi s.l. varied significantly according to localities and farms. Goats located in humid areas were statistically more infected than those located in sub-humid areas. Prevalence rates varied significantly according to age and breed in sheep, and age and tick infestation in goats. This study provides the first insight into the presence of B. burgdorferi s.l. DNA in ruminants in Tunisia, and demonstrates that host species such as goats and sheep may play an important role in natural Lyme disease cycles in this country.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5604/12321966.1219184DOI Listing
September 2016

Detection of novel strains genetically related to Anaplasma platys in Tunisian one-humped camels (Camelus dromedarius).

J Infect Dev Ctries 2015 Oct 29;9(10):1117-25. Epub 2015 Oct 29.

Ecole Nationale de Médecine Vétérinaire, Institution de la Recherche et de l'Enseignement Supérieur Agricoles, Université de La Manouba, 2020 Sidi Thabet, Tunisia.

Introduction: Little information is currently available regarding the presence of Anaplasma species in North African dromedaries. To fill this gap in knowledge, the prevalence, risk factors, and genetic diversity of Anaplasma species were investigated in Tunisian dromedary camels.

Methodology: A total of 226 camels from three different bioclimatic areas were sampled and tested for the presence of Anaplasma species by quantitative polymerase chain reaction (qPCR) and nested polymerase chain reaction (nPCR) assays. Detected Anaplasma strains were characterized by 16S rRNA sequence analysis.

Results: Overall infection rate of Anaplasma spp. was 17.7%, and was significantly higher in females. Notably, A. marginale, A. centrale, A. bovis, and A. phagocytophilum were not detected. Animals were severely infested by three tick species belonging to the genus Hyalomma (H. dromedarii, H. impeltatum, and H. excavatum). Alignment, similarity comparison, and phylogenetic analysis of the 16S rRNA sequence variants obtained in this study suggest that Tunisian dromedaries are infected by more than one novel Anaplasma strain genetically related to A. platys.

Conclusions: This study reports the presence of novel Anaplasma sp. strains genetically related to A. platys in dromedaries from various bioclimatic areas of Tunisia. Findings raise new concerns about the specificity of the direct and indirect diagnostic tests routinely used to detect different Anaplasma species in ruminants and provide useful molecular information to elucidate the evolutionary history of bacterial species related to A. platys.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3855/jidc.6950DOI Listing
October 2015

Molecular Survey of Anaplasma Species in Small Ruminants Reveals the Presence of Novel Strains Closely Related to A. phagocytophilum in Tunisia.

Vector Borne Zoonotic Dis 2015 Oct 22;15(10):580-90. Epub 2015 Sep 22.

1 Laboratoire de Microbiologie, Ecole Nationale de Médecine Vétérinaire, Université de La Manouba , Sidi Thabet, Tunisia .

A survey of Anaplasma species in small ruminants is still lacking in North African countries. In this study, the presence of A. phagocytophilum, A. phagocytophilum-related species, and A. ovis was investigated in a total of 563 healthy small ruminants (303 goats and 260 sheep), from 25 randomly selected flocks sampled in Tunisia. Anaplasma spp. and A. ovis overall infection rates were 95.0% and 93.8% in sheep and 69.6% and 65.3% in goats, respectively. A. phagocytophilum was not detected in any of tested animals. A total of 20 sheep (7.7%) and 144 goats (47.5%) were infected by Anaplasma strains genetically related to A. phagocytophilum. Both in sheep and goats A. ovis prevalence was higher in adults (≥2 years) than in young (<2 years) subjects (p = 0.001 and 0.002 for goats and sheep, respectively). In sheep, A. ovis prevalence was higher in ewes with respect to rams (p = 0.010). The A. ovis infection rate was significantly lower in goats of the local breed (p = 0.049) and it was higher in goats infested by ticks than in not infested animals (p = 0.005). Genetic analysis of the msp4 gene of A. ovis indicated the presence of strains shared by Tunisian sheep and goats. Sequence analysis and phylogenetic studies on the basis of the 16S rRNA gene provided evidence for the circulation of at least two different potentially novel species genetically related to A. phagocytophilum in Tunisian small ruminants. These findings cause concern about specificity of serological tests used for detection of A. phagocytophilum in ruminants and provide additional information for elucidating pathogenesis and molecular epidemiology of A. phagocytophilum and related species.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/vbz.2015.1796DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4593892PMC
October 2015

First molecular survey and novel genetic variants' identification of Anaplasma marginale, A. centrale and A. bovis in cattle from Tunisia.

Infect Genet Evol 2015 Aug 24;34:361-71. Epub 2015 Jun 24.

Laboratoire de Microbiologie, Ecole Nationale de Médecine Vétérinaire, Institution de la Recherche et de l'Enseignement Supérieur Agricoles, Université de La Manouba, 2020 Sidi Thabet, Tunisia. Electronic address:

Few data are available about the presence and distribution of Anaplasma species in cattle in North African countries. In this study prevalence, co-infections, risk factors and genetic diversity of Anaplasma species were evaluated in bovines from Northern Tunisia. A total of 232 cattle from 36 randomly selected farms in three Tunisian localities were investigated for the presence of Anaplasma species in blood by Real-time PCR and/or nested PCR. Overall infection rates of Anaplasma spp., Anaplasma marginale, Anaplasma centrale and Anaplasma bovis were 34.9%, 25.4%, 15.1%, and 3.9%, respectively. Anaplasma phagocytophilum was not detected in cattle. The most common co-infection pattern was an association of A. marginale and A. centrale (11.2%). Five cattle (2.1%) all reared in the sub-humid bioclimatic area, were co-infected by the three Anaplasma species. Molecular prevalence of Anaplasma infection varied significantly according to locality, bioclimatic area, tick infestation and type of breeding. Animals of the Holstein breed were less infected by A. marginale and A. centrale than other breeds. Genetic analysis of A. marginale msp4 gene indicated a high sequence diversity of Tunisian strains, suggesting a multiple introduction of infected cattle from different origins. Phylogenetic studies based on the 16S rRNA gene showed that the most prevalent A. centrale strains were closely related to the A. centrale vaccine strain. Moreover, all A. bovis variants clustered with other A. bovis sequences obtained from domestic and wild ruminant strains. This is the first molecular investigation on Anaplasma species in Tunisian cattle providing pivotal background for designing epidemiological studies and to develop control strategies in the country.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.meegid.2015.06.017DOI Listing
August 2015

First molecular survey of Anaplasma bovis in small ruminants from Tunisia.

Vet Microbiol 2015 Sep 28;179(3-4):322-6. Epub 2015 May 28.

Laboratoire de Microbiologie, Ecole Nationale de Médecine Vétérinaire, Université de La Manouba, 2020 Sidi Thabet, Tunisia. Electronic address:

To date, no information is available regarding the presence of Anaplasma bovis in the South Mediterranean area. In this study, prevalence, risk factors, and genetic diversity of A. bovis were assessed in small ruminants. A total of 563 healthy small ruminants (260 sheep and 303 goats), from 25 randomly selected flocks located in 5 localities from two bioclimatic areas in Tunisia, were investigated for the detection of A. bovis in blood by nested polymerase chain reaction (nPCR) assay. The overall infection rates of A. bovis were 42.7 and 23.8% in sheep and goats, respectively. Goats located in a sub-humid area were statistically more infected than those located in a humid area. A. bovis prevalence rate varied significantly according to sheep and goat flocks, and to the sheep breed. Infection with A. bovis was validated by sequencing. Sequence analysis based on the 16S rRNA gene showed that A. bovis from Tunisian goats and sheep clustered with other strain sequences detected from wild and domestic animals and published in GenBank. This study gives the first insight of presence of A. bovis DNA in small ruminants in Tunisia and suggests that these animal species may be playing an important role in the bovine anaplasmosis natural cycle caused by A. bovis in the South Mediterranean ecosystem.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetmic.2015.05.022DOI Listing
September 2015

Seroprevalence of Anaplasma phagocytophilum in well maintained horses from northern Tunisia.

Trop Biomed 2014 Sep;31(3):432-40

Laboratoire de Microbiologie, Ecole Nationale de Médecine Vétérinaire, Université de la Manouba, 2020 Sidi Thabet, Tunisia.

The aim of the present study was to determine the seroprevalence of Anaplasma phagocytophilum in 343 well maintained horses belonging to 11 horse stables located in northern Tunisia with indirect immunofluorescence test. Overall, 16.3% (56/343) of tested animals were positive. Anti-A. phagocytophilum antibodies were present in horses located in all studied governorates except the governorate of Ben Arous. Nine horse stables out of 11 contained positive animals, the seroprevalence of each one varied from nought to 50%. Seroprevalence varied according to gender, breed and type of activity, contrary to age. Seroprevalence was higher in females than males (21.4 and 9.5% respectively). Similarly, seropositive animals belonging to the English thoroughbred breed was significantly higher (30.2%) than other breeds. According to the utilization of horses, the highest positivity rate (21.1%) was observed in brood mares. Our results demonstrate that A. phagocytophilum infection is widespread in well maintained horses from northern Tunisia, so equine granulocytic anaplasmosis should be suspected by veterinarians in front of suggestive clinical signs like fever, ataxia and reluctance to move.
View Article and Find Full Text PDF

Download full-text PDF

Source
September 2014