Ali Bouattour
University of Tunis El Manar, Institut Pasteur de Tunis, Faculty Member
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%... more
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.
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Additional file 8: Figure S3. Sensitivity of PCR-HRM targeting 7SL RNA and HSP70 genes. Detection limit of PCR-HRM using 7SL RNA and HSP70 genes was determined using tenfold dilutions of DNA from each reference Leishmania isolate,... more
Additional file 8: Figure S3. Sensitivity of PCR-HRM targeting 7SL RNA and HSP70 genes. Detection limit of PCR-HRM using 7SL RNA and HSP70 genes was determined using tenfold dilutions of DNA from each reference Leishmania isolate, representing L. infantum (MHOM/TN/94/LV50), L. major (MHOM/TN/2011/EMPA10), and L. tropica (MHOM/IQ/65/L75). a. 7SL PCR-HRM using L. infantum DNA b. HSP70 PCR-HRM using L. infantum DNA. c. 7SL PCR-HRM using L. major DNA d. HSP70 PCR-HRM using L. major DNA. e. 7SL PCR-HRM using L. tropica DNA f. HSP70 PCR-HRM using L. tropica DNA. The right sections of the figures show the tested samples, which are color-coded according to the amplification result, red when positive and green when negative. In all panels, sample codes correspond to the following DNA amounts: A: 20 ng; B: 10 ng; C: 1 ng; D: 0.1 ng; E: 0.01 ng; F: 0.001 ng; G: 0.0001 ng; H: negative control (no DNA).
Crimean-Congo hemorrhagic fever virus (CCHFV, Nairoviridae family) and Rift Valley fever virus (RVFV, Phenuiviridae family) are zoonotic vector-borne pathogens with clinical relevance worldwide. Our study aimed to determine... more
Crimean-Congo hemorrhagic fever virus (CCHFV, Nairoviridae family) and Rift Valley fever virus (RVFV, Phenuiviridae family) are zoonotic vector-borne pathogens with clinical relevance worldwide. Our study aimed to determine seroprevalences of these viruses and potential risk factors among livestock (cattle, sheep, and goats) in Tunisia. Sera were tested for antibodies against CCHFV (n = 879) and RVFV (n = 699) using various enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence assays (IIFA). The overall seroprevalence of IgG antibodies was 8.6% (76/879) and 2.3% (16/699) against CCHFV and RVFV, respectively. For CCHF seropositivity bioclimatic zones and breed were potential risk factors for the three tested animal species; while the season was associated with cattle and sheep seropositivity, tick infestation was associated with cattle and goats seropositivity and age as a risk factor was only associated with cattle seropositivity. Age and season were significan...
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Background Discovered by Nicolle and Comte in 1908 in Tunisia, Leishmania infantum is an intracellular protozoan responsible for zoonotic canine leishmaniosis (CanL) and zoonotic human visceral leishmaniasis (HVL). It is endemic in... more
Background Discovered by Nicolle and Comte in 1908 in Tunisia, Leishmania infantum is an intracellular protozoan responsible for zoonotic canine leishmaniosis (CanL) and zoonotic human visceral leishmaniasis (HVL). It is endemic in several regions of the world, including Tunisia, with dogs considered as the main domestic reservoir. The geographic expansion of canine leishmaniosis (CanL) has been linked to global environmental changes that have affected the density and the distribution of its sand fly vectors. Methodology/Principal findings In this study, a cross-sectional epidemiological survey on CanL was carried out in 8 localities in 8 bioclimatic areas of Tunisia. Blood samples were taken from 317 dogs after clinical examination. Collected sera were tested by indirect fluorescent antibody test (IFAT; 1:80) for the presence of anti-Leishmania infantum antibodies. The overall seroprevalence was 58.3% (185/317). Among positive dogs, only 16.7% showed clinical signs suggestive of le...
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Table S2. Classification of proteins identified in the salivary glands of Hyalomma dromedarii males. Description of additional files. Accession: protein ID in the database. %coverage: percentage Coverage_ The percentage of all the amino... more
Table S2. Classification of proteins identified in the salivary glands of Hyalomma dromedarii males. Description of additional files. Accession: protein ID in the database. %coverage: percentage Coverage_ The percentage of all the amino acids in the protein sequence that were covered by identified peptides detected in the sample. -10logP: the P-value is converted to -10log10 (P-value). In PEAKS, this value is denoted by -10lgP as lg is the ISO reserved notation for log10. By this conversion, a more significant match will have a higher -10lgP value. Additionally, a P-value of 1% is equivalent to -10lgP of 20. #Peptides: number of peptides identified following LC-MS/MS analysis for a single protein. #Unique: Unique peptides_peptides with the same amino acid sequence but different charges or with different modifications are grouped together and counted only once. Avg.Mass: the average mass of a single protein obtained by summing the average atomic masses of the constituent elements. De...
Results of the relationship between percentage of autogeny of Cx. pipiens forms and the type of breeding site, based on a Generalized Linear Model with Poisson distribution. (PDF 313Â kb)
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Relationship between the different types of habitat and breeding site and the proportion of Cx. pipiens based on a Generalized Linear Model (GLM) with Poisson distribution. (PDF 98Â kb)
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Relationship between the bioclimatic region and the proportion of Cx. pipiens forms based on a Generalized Linear Model (GLM) with Poisson distribution. (PDF 98Â kb)
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Additional file 1. Presence of Aedes aegypti and Aedes albopictus and case data of Dengue, chikungunya and yellow fever in the EMR.
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Distribution of Bartonella species by bioclimatic zones, site, flea species and animal host and partial sequencing analysis of gltA gene and the ITS region. (PDF 23 kb)
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Table S2. Housekeeping class transcripts and their annotations. (XLSX 775 kb)
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Table S1. Annotated transcripts of H. dromedarii salivary glands. (XLSX 17611 kb)
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Hemostatic disorders are caused either by platelet-related dysfunctions, defective blood coagulation, or by a combination of both, leading to an increased susceptibility to cardiovascular diseases (CVD) and other related illnesses. The... more
Hemostatic disorders are caused either by platelet-related dysfunctions, defective blood coagulation, or by a combination of both, leading to an increased susceptibility to cardiovascular diseases (CVD) and other related illnesses. The unique specificity of anticoagulants from hematophagous arthropods, such as ticks, suggests that tick saliva holds great promise for discovering new treatments for these life-threatening diseases. In this study, we combined in silico and in vitro analyses to characterize the first recombinant serpin, herein called Dromaserpin, from the sialotranscriptome of the Hyalomma dromedarii tick. Our in silico data described Dromaserpin as a secreted protein of ~43 kDa with high similarities to previously characterized inhibitory serpins. The recombinant protein (rDromaserpin) was obtained as a well-structured monomer, which was tested using global blood coagulation and platelet aggregation assays. With this approach, we confirmed rDromaserpin anticoagulant act...
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Small wild mammals are an important element in the emergence and transmission of vector-borne pathogens (VBPs). Among these species, hedgehogs have been found to be a reservoir of VBPs and host of arthropod vectors. Surveillance of VBPs... more
Small wild mammals are an important element in the emergence and transmission of vector-borne pathogens (VBPs). Among these species, hedgehogs have been found to be a reservoir of VBPs and host of arthropod vectors. Surveillance of VBPs in wildlife and their arthropods are crucial in a one health context. We conducted an exploratory study to screen Atelerix algirus hedgehogs and their infesting ticks and fleas for VBPs using a high throughput microfluidic real-time PCR system. Tested biopsies from hedgehogs were found to be naturally infected by Theileria youngi, Hepatozoon sp., Ehrlichia ewingii, Coxiella burnetii, and Candidatus Ehrlichia shimanensis. Similarly, Haemaphysalis erinacei and Rhipicephalus sanguineus tick species were infected by Ehrlichia ewingii, Rickettsia spp., Rickettsia massiliae, Borrelia sp., Coxiella burnetii, Rickettsia lusitaniae and Anaplasma sp. Archaeopsylla erinacei fleas were infected by Rickettsia asembonensis, Coxiella burnetii, and Rickettsia massil...
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A paucity of studies is available on haemoparasites in dogs in Tunisia. In this study, we used molecular techniques (PCR/sequencing) to detect and characterize haemoprotozoa in sick dogs from Tunisia. A total of 99 dogs displaying such... more
A paucity of studies is available on haemoparasites in dogs in Tunisia. In this study, we used molecular techniques (PCR/sequencing) to detect and characterize haemoprotozoa in sick dogs from Tunisia. A total of 99 dogs displaying such clinical symptoms as fever, anorexia, and depression were presented for treatment to the hospital of the Veterinary School of Sidi Thabet (Tunisia). Among dogs screened by PCR, five (5%) proved to be infected with a hemoprotozoa species. An analysis of all the sequences that were obtained enabled us to identify two species of Protozoa: Babesia vogeli (in three dogs) and Hepatozoon canis (in two other dogs). This is the first time that an infection of dogs by Hepatozoon canis in Tunisia has been reported. Veterinary practitioners should be aware that these two haemoparasites can infect dogs and should include them in any differential diagnosis of clinical illnesses with manifestations compatible with tick-borne diseases.
Research Interests: Veterinary Medicine, Biology, Medicine, Babesia, Canis, and 3 moreBabesiosis, Hepatozoon, and Babesia canis
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Research Interests: Entomology, Medical Microbiology, Medical and Veterinary Entomology, Biology, Capacity Building, and 15 moreMedical Entomology, Medicine, DNA Barcoding, Biological Sciences, Mediterranean Sea, Genus, Mosquito Control, Molecular systematics and taxonomy, Mosquito Ecology, Fen Bilimleri, Larva, Intraspecific Competition, Culicidae taxonomy, desease vector, and Medical and Health Sciences
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%... more
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...
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Research Interests: Biology, Virology, Medicine, Multidisciplinary, Disease susceptibility, and 15 moreNorth Africa, Female, Animals, Old World, Culex, PLoS one, Experimental Infection, Emerging disease, Rift Valley Fever, Species Specificity, Culex pipiens, Rift Valley fever virus, Outbreak, Insect Vectors, and West Nile
SUMMARYDescriptions of Babesia occultans have previously been restricted to sub-Saharan Africa. Here, we report the finding, for the first time, of this low or non-pathogenic bovine Babesia species in Tunisia, northern Africa. B.... more
SUMMARYDescriptions of Babesia occultans have previously been restricted to sub-Saharan Africa. Here, we report the finding, for the first time, of this low or non-pathogenic bovine Babesia species in Tunisia, northern Africa. B. occultans DNA was detected by molecular methods in Hyalomma marginatum unfed ticks collected in 3 bioclimatic regions of Tunisia. The near-full-length 18S rRNA gene was sequenced and compared with related sequences retrieved from GenBank. Phylogenetic analysis indicated that other sequences deposited as Babesia sp. could also correspond to B. occultans, suggesting that this species may have a wide distribution in Mediterranean and Asiatic regions, and not only in sub-Saharan Africa as previously described. A B. occultans-specific Reverse Line Blot (RLB) oligonucleotide probe was designed for future epidemiological studies that would help to clarify this possibility.
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Background Anaplasma phagocytophilum , the causative agent of granulocytic anaplasmosis, affects several species of wild and domesticated mammals, including horses. We used direct and indirect methods to compare and evaluate exposure to... more
Background Anaplasma phagocytophilum , the causative agent of granulocytic anaplasmosis, affects several species of wild and domesticated mammals, including horses. We used direct and indirect methods to compare and evaluate exposure to A. phagocytophilum in horses in northern Tunisia. Methods Serum from 60 horses was tested by IFA for antibodies to A. phagocytophilum , and whole blood was tested for A. phagocytophilum 16S rRNA gene using a nested-PCR. To examine the risk of A. phagocytophilum transmission, 154 ticks that had been collected from horses were examined for the presence of A. phagocytophilum by nested-PCR targeting 16S rRNA gene. Results This is the first time that A. phagocytophilum has been detected in horses in Tunisia, with an overall seroprevalence of 40/60 (67%). Six of the seroreactive samples (10%) had an IFA titer of 1:80, 14 (23%) of 1:160, 8 (13%) of 1:320 and 12 (20%) a titer 1 ≥ 640. The seroprevalence revealed no significant regional and sex differences. I...
Research Interests: Veterinary Medicine, Medical Microbiology, Biology, Medicine, Ticks, and 14 moreTunisia, Female, Animals, Male, Polymerase Chain Reaction, Horses, Public health systems and services research, Anaplasmosis, Ehrlichiosis, Seroprevalence, Ribosomal DNA, Anaplasma Phagocytophilum, Molecular Sequence Data, and Titer
A broad-range 16S rRNA gene PCR assay followed by partial sequencing of the 16S rRNA gene was used for the detection of members of the family Anaplasmataceae in ticks in North Africa. A total of 418 questing Ixodes ricinus ticks collected... more
A broad-range 16S rRNA gene PCR assay followed by partial sequencing of the 16S rRNA gene was used for the detection of members of the family Anaplasmataceae in ticks in North Africa. A total of 418 questing Ixodes ricinus ticks collected in Tunisia and Morocco, as well as 188 Rhipicephalus ticks from dogs and 52 Hyalomma ticks from bovines in Tunisia, were included in this study. Of 324 adult I. ricinus ticks, 16.3% were positive for Ehrlichia spp., whereas only 3.4 and 2.8% of nymphs and larvae, respectively, were positive. A large heterogeneity was observed in the nucleotide sequences. Partial sequences identical to that of the agent of human granulocytic ehrlichiosis (HGE) were detected in I. ricinus and Hyalomma detritum , whereas partial sequences identical to that of Anaplasma platys were detected in Rhipicephalus sanguineus . However, variants of Anaplasma , provisionally designated Anaplasma- like, were predominant in the I. ricinus tick population in Maghreb. Otherwise, tw...
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Ticks ( n = 663) and fleas ( n = 470) collected from domestic animals from southeastern Tunisia were screened for Rickettsia infection using reverse line blot assay. Evidence of spotted fever group Rickettsia was obtained. We detected... more
Ticks ( n = 663) and fleas ( n = 470) collected from domestic animals from southeastern Tunisia were screened for Rickettsia infection using reverse line blot assay. Evidence of spotted fever group Rickettsia was obtained. We detected Rickettsia felis in fleas, Rickettsia massiliae Bar 29 and the Rickettsia conorii Israeli spotted fever strain in ticks, and Rickettsia conorii subsp. conorii and Rickettsia spp. in both arthropods. The sensitivity of the adopted technique allowed the identification of a new association between fleas and R. conorii subsp. conorii species. The presence of these vector-borne Rickettsia infections should be considered when diagnosing this disease in humans in Tunisia.
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Tick-borne relapsing fever (TBRF) is caused by Borrelia species transmitted to humans by infected Ornithodoros sp. ticks. The disease has been rarely described in North Africa, and in Tunisia the local transmission of TBRF seems to have... more
Tick-borne relapsing fever (TBRF) is caused by Borrelia species transmitted to humans by infected Ornithodoros sp. ticks. The disease has been rarely described in North Africa, and in Tunisia the local transmission of TBRF seems to have disappeared or is undiagnosed. A longitudinal study was conducted in 14 sites located in four different bioclimatic zones of Tunisia to assess both the distribution of Ornithodoros sp. and their infection rate with the relapsing fever Borrelia sp. Three polymerase chain reaction methods targeting the 16S rRNA, the intergenic spacer, and the fla (flagellin) genes were used and phylogenetic analyses were carried out. Three hundred and fifty-eight specimens of Ornithodoros were collected: O. erraticus (previously termed ‘‘small variety’’) (n 190) and O. normandi (n 168). Borrelia crocidurae DNA was detected in 15.1 % of O. erraticus (small variety) (24 out of the 159 randomly selected for testing) collected in rodent burrows situated in the arid and Sah...
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The present study aimed to update the list of Aedes mosquito species occurring in Tunisia and to test the vector competence of Aedes (Ochlerotatus) caspius (Pallas) and Ae. (Ochlerotatus) detritus (Haliday), the locally most abundant and... more
The present study aimed to update the list of Aedes mosquito species occurring in Tunisia and to test the vector competence of Aedes (Ochlerotatus) caspius (Pallas) and Ae. (Ochlerotatus) detritus (Haliday), the locally most abundant and widespread species, to transmit Zika virus (ZIKV). In 2017–2018, mosquito larvae were collected from 39 different larval habitats in seven bioclimatic zones of Tunisia. The salinity and pH of each breeding site were measured. The survey revealed the presence of 10 Aedes species in Tunisia: Ae. (Stegomyia) albopictus (Skuse), Ae. (Ochlerotatus) berlandi (Séguy), Ae. caspius, Ae. detritus, Ae. (Finlaya) echinus (Edwards), Ae. (Finlaya) geniculatus (Olivier), Ae. (Acartomyia) mariae (Sergent and Sergent), Ae. (Ochlerotatus) pulcritarsis (Rondani), Ae. (Aedimorphus) vexans (Meigen), and Ae. (Fredwardsius) vittatus (Bigot). Of these 10 species, Ae. caspius and Ae. detritus were the most abundant in Tunisia. Aedes detritus and Ae. caspius larvae were rear...
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Aedes albopictus (Skuse) is a widespread invasive mosquito vector species with a distribution including tropical and temperate climates; its range is still expanding. Aedes albopictus populations were recently detected in Morocco and... more
Aedes albopictus (Skuse) is a widespread invasive mosquito vector species with a distribution including tropical and temperate climates; its range is still expanding. Aedes albopictus populations were recently detected in Morocco and Algeria, the countries neighboring Tunisia, but never in Tunisia. In 2018, we initiated an intensive field study using BG-Sentinel Traps, ovitraps, larval surveys, and citizens’ reports to determine whether Ae. albopictus populations exist in Tunisia. In October 2018, we collected adults and larval stages of Ae. albopictus in Carthage, Amilcar, and La Marsa, less than 20 km, northeast of Tunis, the Tunisian capital. These Ae. albopictus larvae were primarily collected from Phoenician funeral urns at the archeological site of Carthage. This is, to our knowledge, the first detection of Ae. albopictus in Tunisia.
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Hard ticks are hematophagous ectoparasites characterized by their long-term feeding. The saliva that they secrete during their blood meal is their crucial weapon against host-defense systems including hemostasis, inflammation and... more
Hard ticks are hematophagous ectoparasites characterized by their long-term feeding. The saliva that they secrete during their blood meal is their crucial weapon against host-defense systems including hemostasis, inflammation and immunity. The anti-hemostatic, anti-inflammatory and immune-modulatory activities carried out by tick saliva molecules warrant their pharmacological investigation. The Hyalomma dromedarii Koch, 1844 tick is a common parasite of camels and probably the best adapted to deserts of all hard ticks. Like other hard ticks, the salivary glands of this tick may provide a rich source of many compounds whose biological activities interact directly with host system pathways. Female H. dromedarii ticks feed longer than males, thereby taking in more blood. To investigate the differences in feeding behavior as reflected in salivary compounds, we performed de novo assembly and annotation of H. dromedarii sialotranscriptome paying particular attention to variations in gende...
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The systematics of the genera and subgenera within the soft tick family Argasidae is not adequately resolved. Different classification schemes, reflecting diverse schools of scientific thought that elevated or downgraded groups to genera... more
The systematics of the genera and subgenera within the soft tick family Argasidae is not adequately resolved. Different classification schemes, reflecting diverse schools of scientific thought that elevated or downgraded groups to genera or subgenera, have been proposed. In the most recent classification scheme, Argas and Ornithodoros are paraphyletic and the placement of various subgenera remains uncertain because molecular data are lacking. Thus, reclassification of the Argasidae is required. This will enable an understanding of soft tick systematics within an evolutionary context. This study addressed that knowledge gap using mitochondrial genome and nuclear (18S and 28S ribosomal RNA) sequence data for representatives of the subgenera Alectorobius, Argas, Chiropterargas, Ogadenus, Ornamentum, Ornithodoros, Navis (subgen. nov.), Pavlovskyella, Persicargas, Proknekalia, Reticulinasus and Secretargas, from the Afrotropical, Nearctic and Palearctic regions. Hard tick species (Ixodidae) and a new representative of Nuttalliella namaqua (Nuttalliellidae), were also sequenced with a total of 83 whole mitochondrial genomes, 18S rRNA and 28S rRNA genes generated. The study confirmed the utility of next-generation sequencing to retrieve systematic markers. Paraphyly of Argas and Ornithodoros was resolved by systematic analysis and a new species list is proposed. This corresponds broadly with the morphological cladistic analysis of Klompen and Oliver (1993). Estimation of divergence times using molecular dating allowed dissection of phylogeographic patterns for argasid evolution. The discovery of cryptic species in the subgenera Chiropterargas, Ogadenus and Ornithodoros, suggests that cryptic speciation is common within the Argasidae. Cryptic speciation has implications for past biological studies of soft ticks. These are discussed in particular for the Ornithodoros (Ornithodoros) moubata and Ornithodoros (Ornithodoros) savignyi groups.
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Aedes-borne diseases as dengue, zika, chikungunya and yellow fever are an emerging problem worldwide, being transmitted by Aedes aegypti and Aedes albopictus. Lack of up to date information about the distribution of Aedes species hampers... more
Aedes-borne diseases as dengue, zika, chikungunya and yellow fever are an emerging problem worldwide, being transmitted by Aedes aegypti and Aedes albopictus. Lack of up to date information about the distribution of Aedes species hampers surveillance and control. Global databases have been compiled but these did not capture data in the WHO Eastern Mediterranean Region (EMR), and any models built using these datasets fail to identify highly suitable areas where one or both species may occur. The first objective of this study was therefore to update the existing Ae. aegypti (Linnaeus, 1762) and Ae. albopictus (Skuse, 1895) compendia and the second objective was to generate species distribution models targeted to the EMR. A final objective was to engage the WHO points of contacts within the region to provide feedback and hence validate all model outputs. The Ae. aegypti and Ae. albopictus compendia provided by Kraemer et al. (Sci Data 2:150035, 2015; Dryad Digit Repos, 2015) were used ...
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Hard ticks (Acari: Ixodidae) are blood-sucking ectoparasites characterized by the extended period of their attachment to their host. To access their bloodmeal, ticks secrete saliva containing a range of molecules that target the... more
Hard ticks (Acari: Ixodidae) are blood-sucking ectoparasites characterized by the extended period of their attachment to their host. To access their bloodmeal, ticks secrete saliva containing a range of molecules that target the host's inflammation, immune system, and hemostatic components. Some of these molecules reportedly possess antiangiogenic and antitumor properties. The present study describes our investigation, the first of its kind, of the antiangiogenic and antitumoral effects of the Hyalomma dromedarii Koch, 1844 (Acari: Ixodidae), salivary gland extract (SGE), which inhibited the adhesion and migration of Human Umbilical Vein Endothelial Cells (HUVECs) in a dose-dependent manner, as well as angiogenesis in the Chick Chorioallantoic Membrane model. Interestingly, H. dromedarii SGE exerted an antiproliferative effect on U87 glioblastoma cells and inhibited their adhesion and migration to fibrinogen. These results open up new possibilities for characterizing and developing new molecules involved in the key steps of tumor progression.
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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... more
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.
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Research Interests: Genetics, Molecular Epidemiology, Tunisia, Sheep, Animals, and 5 moreGoats, Anaplasma, SHEEP DISEASES, Anaplasmosis, and Seasons
Arboviruses, viruses transmitted by arthropods such as mosquitoes, ticks, sandflies, and fleas are a significant threat to public health because of their epidemic and zoonotic potential. The geographical distribution of mosquito-borne... more
Arboviruses, viruses transmitted by arthropods such as mosquitoes, ticks, sandflies, and fleas are a significant threat to public health because of their epidemic and zoonotic potential. The geographical distribution of mosquito-borne diseases such as West Nile (WN), Rift Valley fever (RVF), Dengue, Chikungunya, and Zika has expanded over the last decades. Countries of the Mediterranean and Black Sea regions are not spared. Outbreaks of WN are repeatedly reported in the Mediterranean basin. Human cases of RVF were reported at the southern borders of the Maghreb region. For this reason, establishing the basis for the research to understand the potential for the future emergence of these and other arboviruses and their expansion into new geographic areas became a public health priority. In this context, the European network "MediLabSecure" gathering laboratories in 19 non-EU countries from the Mediterranean and Black Sea regions seeks to improve the surveillance (of animals,...
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... more
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 ...
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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... more
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 s...
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Diagnosis of rickettsioses had largely benefited from the development of molecular techniques. Unfortunately, in Tunisia, despite the large number of rickettsial cases registered every year, the Rickettsia species remain unidentified. In... more
Diagnosis of rickettsioses had largely benefited from the development of molecular techniques. Unfortunately, in Tunisia, despite the large number of rickettsial cases registered every year, the Rickettsia species remain unidentified. In this study, we aimed to detect the Rickettsia species in clinical samples using molecular tests. A study was established to analyze skin biopsies, cutaneous swabs, and cerebrospinal fluid samples taken from clinically suspected patients to have rickettsial infection. Two molecular techniques were used to detect Rickettsia DNA: quantitative real time PCR (qPCR) and reverse line blot test (RLB). An analysis of the RLB hybridization assay results revealed the presence of Rickettsia DNA in skin biopsies (40.6%) and swabs (46.7%). Rickettsia conorii was the most prevalent identified species among tested samples. Other species of interest include Rickettsia typhi and Rickettsia massiliae. Using qPCR positivity rates in skin biopsies was 63.7% against 80% in swabs. R. conorii was the most frequently detected species, followed by R. typhi. The agreement between the two techniques was 68.6% (kappa=0.33). Molecular tests, especially using specific probes qPCR, allow for a rapid, better and confident diagnosis in clinical practice. They improve the survey of Mediterranean spotted fever which is considered to be the most important rickettsial infection in humans in Tunisia.
Research Interests:
Physiological and molecular characteristics of natural populations of Culex pipiens Linnaeus, 1758 (Diptera: Culicidae) were investigated to elucidate how this species is potentially involved in the transmission of West Nile virus in... more
Physiological and molecular characteristics of natural populations of Culex pipiens Linnaeus, 1758 (Diptera: Culicidae) were investigated to elucidate how this species is potentially involved in the transmission of West Nile virus in Tunisia. A total of 215 Cx. pipiens females from 11 breeding habitats were analysed in the laboratory to estimate autogeny and stenogamy rates. They were tested individually for the locus CQ11 to distinguish between the two Cx. pipiens forms, pipiens and molestus. All tested Cx. pipiens populations were stenogamous. Females from underground breeding sites were all autogeneous, whereas females from above-ground habitats were mostly anautogeneous. Of all the females tested, 59.7% were identified as pipiens, 22.4% as molestus, and 17.9% as hybrid pipiens/molestus. Furthermore, both Cx. pipiens forms and their hybrids were found to co-occur in sympatry in all sites. The results of this study represent the first evidence that both Cx. pipiens forms and their...