Publications by authors named "Rachid Selmi"

14 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.
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http://dx.doi.org/10.3389/fvets.2021.676896DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8187766PMC
May 2021

First report on Bartonella henselae in dromedary camels (Camelus dromedarius).

Infect Genet Evol 2020 11 7;85:104496. Epub 2020 Aug 7.

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

Bartonellosis is one of the clinically underdiagnosed emerging bacterial diseases among domestic livestock, particularly in camels. Until now, the natural infection of camels with Bartonella species was not investigated in Tunisia. In the attempt of filling this gap in knowledge, a total of 412 dromedary camels (Camelus dromedarius) as well as 300 associated ticks (Hyalomma dromedarii (160; 53.4%), H. impeltatum (131; 43.6%) and H. excavatum (9; 3%) were screened for the presence of Bartonella spp. by PCR followed by a sequencing step through the amplification of the rpoB gene. Positive samples were then tested and further characterized by the combined use of the ftsZ and gltA genes. Fifteen camels (3.6%) were found to be positive to Bartonella spp. However, there was no evidence of Bartonella DNA in any of the analyzed ticks. Risk factors' analysis shows that camels derived from arid and semi-arid bioclimatic areas were more infected than those originated from desert area. Molecular characterization and phylogenetic analysis revealed the occurrence of novel B. henselae genotypes closely related to those isolated from humans, cats, and lions. By combining the characteristics of each single gene with those of concatenated sequences, we report here the first molecular detection of B. henselae in the dromedary camel suggesting a possible involvement of camelids as hosts or reservoirs in the transmission cycle of this emerging bacterium in arid and saharan areas.
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http://dx.doi.org/10.1016/j.meegid.2020.104496DOI Listing
November 2020

Seroprevalence and associated risk factors of Chlamydia abortus infection in ewes in Tunisia.

Comp Immunol Microbiol Infect Dis 2020 May 31;71:101500. Epub 2020 May 31.

Laboratory of Microbiology and Immunology, National School of Veterinary Medicine, Institution of Agricultural Research and Higher Education, University of Manouba, 2020 Sidi Thabet, Tunisia.

Enzootic abortion of ewes (EAE) caused by Chlamydia abortus is a disease of ruminants that results in serious economic losses in livestock industry. The zoonotic potential of the pathogen adds a public health concern on the efforts to control the disease. We report herein a cross-sectional study that was conducted during the lambing season (June and July) in Tunisia to estimate the seroprevalence of C. abortus infection in large sheep herds with abortion history. A total of 803 ewes were sampled and tested using indirect enzyme linked immunosorbent assay (iELISA). The overall apparent seroprevalence at herd and individual levels were 58 % (95 %CI = 39-74.5 %) and 6.6 % (95 %CI = 4.9-8.3 %), respectively. Significant risk factors investigated using univariate and multivariate analyses were history of infertility (OR = 5.7; 95 %CI = 3.05-10.66), the number of reproductive ewes (OR = 2.1; 95 %CI = 1.12-3.94), the control of new animals at introduction (OR = 4.35; 95 %CI = 2.46-7.68), the sharing of drinking water (OR = 2.18; 95 %CI = 1.22-3.9), the exchange of breeding males (OR = 2.56; 95 %CI = 1.003-6.54), the disposal of abortion materials without precaution (OR = 4.36; 95 %CI = 2.42-7.87), the lack of lambing barn (OR = 2.39; 95 %CI = 1.13-5.04), the non-application of hygienic post-abortion measures (OR = 10.35; 95 %CI = 5.28-20.26) and the manure management (OR = 11.35; 95 %CI = 3.26-39.48). To the best of our knowledge, this is the first sero-epidemiological survey conducted on an abortive disease in Tunisian ewes that investigated the risk factors of C. abortus infection.
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http://dx.doi.org/10.1016/j.cimid.2020.101500DOI Listing
May 2020

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

First serological evidence of the Rift Valley fever Phlebovirus in Tunisian camels.

Acta Trop 2020 Jul 20;207:105462. Epub 2020 Apr 20.

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

Rift Valley fever (RVF) is a mosquito-borne zoonosis that severely impacts livelihoods, national and international economies, and human health. Few studies have investigated the prevalence of this infection in Tunisian livestock. The present report aimed to update the epidemiological status and identify the risk factors associated with this RVF virus infection in the one-humped dromedary camel from arid areas. A total of 470 sera of apparently healthy camels (Camelus dromedarius) were collected from six governorates from southern and central Tunisia. Samples were tested by a competitive Enzyme Linked Immunosorbent Assay (ELISA). An overall, 162 camels (34%, 95%CI: 0.1-0.4) were seropositive to RVF virus antigen. Logistic regression model revealed three potential risk factors associated with the infection. A meaningful high seropositivity was observed among aged camels (>10 years-old) (40%) (P=0.001; OR=3.367). Besides, camels raised in small flocks particularly intended for meat production showed a high level of seropositivity (37%) (P=0.013; OR=13.173). Animals having close contact with other ruminants showed high seroprevalence (37%) (P=0.022; OR=10.919). This report indicated that Tunisian one-humped dromedaries were exposed to this virus and may contribute to its dissemination among farmers and other livestock. Furthers studies are urgently required to isolate and characterize this virus, evaluate the potential risk of human infection particularly in farmers, veterinarians and slaughterhouse workers and finally to program a serious strategy for RVF control.
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http://dx.doi.org/10.1016/j.actatropica.2020.105462DOI Listing
July 2020

Molecular epidemiology and phylogeny of spotted fever group Rickettsia in camels (Camelus dromedarius) and their infesting ticks from Tunisia.

Transbound Emerg Dis 2020 Mar 15;67(2):733-744. Epub 2019 Nov 15.

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

Rickettsia species are adapted to a wide range of specific animal hosts. Camels (Camelus dromedarius) have been identified as a carrier of various zoonotic pathogens and became a focus of growing public health interest. This study reported the occurrence of rickettsial infection in camels and infesting ticks from five Tunisian governorates. Based on ompB PCR, eight out of 293 camels (2.7%) were found to be infected with Rickettsia spp. Furthermore, 13 tick specimens of Hyalomma impeltatum (10.4%) and 9 of H. dromedarii (8.0%) harboured DNA of Rickettsia bacteria with an overall prevalence rate of 9.2% (22/237). Molecular prevalence of Rickettsia infection varied significantly according to tick infestation for camels and among tick genders. Five rickettsial species, showing a potential public health interest, were revealed by sequencing. Based on ompB partial sequences, five species were identified corresponding to R. aeschlimannii, R. monacensis, R. helvetica and R. massiliae in camels and to R. africae, R. aeschlimannii, R. monacensis and R. helvetica in ticks. Based on ompA typing, three species were revealed corresponding to R. africae and R. monacensis in camels and to R. africae, R. aeschlimannii and R. monacensis in ticks. This is the first report consolidating the hypothesis that camels may serve as potential hosts for Rickettsia spp. and Hyalomma spp. ticks as possible vectors in arid and Saharan areas of Tunisia. The present data highlight the importance of preventive measures and survey that must be implemented in camel herds in order to limit the spread of these vector-borne bacteria to animals and humans.
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http://dx.doi.org/10.1111/tbed.13392DOI Listing
March 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.
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http://dx.doi.org/10.1016/j.mcp.2019.101467DOI Listing
December 2019

Genetic diversity of groEL and msp4 sequences of Anaplasma ovis infecting camels from Tunisia.

Parasitol Int 2020 Feb 10;74:101980. Epub 2019 Sep 10.

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

To date, no information is available regarding the infection of camels (Camelus dromedarius) by Anaplasma ovis in North African region. Several animal species can be infected by A. ovis which further complicates its natural infection cycle. In this paper, we investigated the occurrence and the genetic diversity of A. ovis in camels and ticks collected from them in Tunisia and the risk factor analysis. Camel blood samples (n = 412) and tick (n = 300) samples, identified as Hyalomma dromedarii (n = 149, 49.6%), H. impeltatum (n = 142, 47.3%) and H. excavatum (n = 9, 3%), were analyzed by conventional PCR followed by the sequencing of msp4 and groEL genes. A. ovis DNA was identified in five camels (1.2%), but not in infesting ticks (0%). The microscopic examination revealed the specific infection of camel erythrocytes by Anaplasma inclusions. The msp4 and groEL typing confirmed the natural infection of camels by A. ovis and revealed two different msp4 genotypes earlier detected in Tunisian small ruminants and their infested ticks, and five different and novel groEL genetic variants forming a separately sub-cluster within A. ovis cluster. The occurrence of different A. ovis strains specific to camels associated with a low prevalence of this Anaplasma species in camels may enrich knowledge regarding the distribution and the transmission cycle of this bacterium in arid and Saharan areas of Tunisia.
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http://dx.doi.org/10.1016/j.parint.2019.101980DOI Listing
February 2020

Molecular detection and genetic characterization of the potentially pathogenic Coxiella burnetii and the endosymbiotic Candidatus Midichloria mitochondrii in ticks infesting camels (Camelus dromedarius) from Tunisia.

Microb Pathog 2019 Nov 6;136:103655. Epub 2019 Aug 6.

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

Tick-borne bacteria are considered to be emerging in camels, but data about their occurrence in Tunisian dromedaries and their infesting ticks remain scarce. In this study, 412 camel blood samples and 327 partially engorged ticks were collected and tested for the presence of Coxiella burnetii and/or related strains, and Rickettsiales bacteria. Coxiella burnetii was detected in 9 Hyalomma impeltatum and 3 H. dromedarii with an overall prevalence rate of 3.6% (12/327). Candidatus Midichloria mitochondrii DNA was identified in 16 H. impeltatum and 10 H. dromedarii with an overall prevalence rate of 8% (26/327). Six ticks (2%) were found to be co-infected with these two bacteria. No positive DNA camel blood sample was observed for both bacteria. Genotyping and phylogenetic analysis of obtained C. burnetii partial sequences based on the IS1111 and htpB genes revealed 99-100% similarity to the pathogenic C. burnetii strains isolated from humans, ruminants and ticks, and that were genetically distant to those isolated from all endosymbiotic related strains (Coxiella-like bacteria). The analysis of the rickettsial partial sequences of the 16S rRNA gene showed 100% similarity to Ca. M. mitochondrii strains infecting Ixodid ticks and dogs. This is the first time that C. burnetii and Ca. M. mitochondrii have been detected in ticks from Tunisia, which raises the possibility of the involvement of Hyalomma tick species in the active diffusion of these bacteria among camels, other domestic animals and humans.
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http://dx.doi.org/10.1016/j.micpath.2019.103655DOI Listing
November 2019

Improving specific detection and updating phylogenetic data related to Anaplasma platys-like strains infecting camels (Camelus dromedarius) and their ticks.

Ticks Tick Borne Dis 2019 10 12;10(6):101260. Epub 2019 Jul 12.

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

In camels and their infesting ectoparasites, specific detection of pathogenic Anaplasma platys and genetically related strains (A. platys-like strains) remains problematic. This requires sequencing of the hemi-nested PCR products specific to A. platys and related strains. In this study, a PCR/RFLP method, earlier developed for specific detection of A. platys-like strains in animal species other than camels, was adapted in order to subtype A. platys-like strains isolated from camels and their ticks and to differentiate them from pathogenic A. platys without going through a sequencing step. This approach was used for investigating the infections with A. platys and related strains in 412 Camelus dromedarius camels and 334 feeding ticks from five Tunisian governorates. Microscopic examination using Giemsa-stained blood smears was performed in order to specify which types of cells were infected. Ticks were identified as Hyalomma dromedarii (n = 164, 49%), H. impeltatum (n = 161, 48.3%) and H. excavatum (n = 9, 2.7%). A. platys was not detected in any of the tested camels or ticks. The overall prevalence of A. platys-like strains was 5.6% (23/412) in camels and microscopic examination of infected cells showed a tropism for neutrophil granulocytes. One tick identified as H. dromedarii out of 327 analyzed ticks was found to be infected with A. platys-like strains (0.3%). Alignment, identity comparison and phylogenetic analysis of the 16S rRNA partial sequences obtained in this study suggest that Tunisian dromedaries and feeding ticks are infected with different Anaplasma strains genetically related to A. platys. Sequence analysis and phylogenetic study based on the groEL gene confirm the RFLP results and show that camel strains formed a separate sub-cluster relatively close to A. platys-like strains infecting Tunisian cattle. This adapted RFLP assay allows fast and specific detection of pathogenic A. platys and A. platys-like strains in camels and infesting ticks and has the intrinsic potential of revealing co-infections with these two types of bacteria in the same sample, reducing the time and costs associated with cloning and sequencing during molecular diagnosis.
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http://dx.doi.org/10.1016/j.ttbdis.2019.07.004DOI Listing
October 2019

Various Inc-type plasmids and lineages of Escherichia coli and Klebsiella pneumoniae spreading blabla and mcr-1 genes in camels in Tunisia.

J Glob Antimicrob Resist 2019 12 14;19:280-283. Epub 2019 May 14.

Unité Antibiorésistance et Virulence Bactériennes, Université de Lyon - ANSES Site de Lyon, Lyon, France. Electronic address:

Objectives: Resistance to extended-spectrum cephalosporins, fluoroquinolones and colistin is under constant scrutiny in food-producing animals worldwide. However, little is known about camels, which provide milk and meat for human consumption, and are attractions for tourists to ride in arid regions. This study assessed the role of camels as potential reservoirs of these resistance determinants.

Methods: Faecal swabs were collected from 232 camels in Tunisia between April 2016 and July 2018. Enterobacteriaceae were detected on MacConkey agar and extended-spectrum β-lactamase (ESBL)-producers on the same medium supplemented with cefotaxime. Antimicrobial resistance was assessed by disc diffusion, and ESBL-producing isolates were further characterised by phylogrouping (for Escherichia coli, E. coli) and multilocus sequence typing. Genetic support of the bla and mcr-1 genes was identified by plasmid-typing and Southern blot.

Results: E. coli were identified in 163 of 232 (70.3%) and Klebsiella pneumoniae (K. pneumoniae) in 16 of 232 (6.9%) of the dominant flora. Three E. coli and one K. pneumoniae (1.3% and 0.4%, respectively) were found on cefotaxime-enriched media. One K. pneumoniae and one E. coli from a tourist farm harboured the bla gene on an IncY plasmid, while the two E. coli from the butchery sector displayed the bla gene on an IncI1 plasmid and colocalisation of the bla and mcr-1 genes on an IncHI2 plasmid.

Conclusions: This study reported ESBL-producing Enterobacteriaceae in Tunisian camels from both tourist and meat-producing sectors. This was the first description of the mcr-1 gene in a meat-producing camel. Although not alarming, this context needs specific attention to avoid camels becoming a bigger reservoir for multidrug-resistant Enterobacteriaceae.
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http://dx.doi.org/10.1016/j.jgar.2019.05.007DOI 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.
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http://dx.doi.org/10.1016/j.actatropica.2018.12.034DOI Listing
March 2019

Coxiella burnetii in Tunisian dromedary camels (Camelus dromedarius): Seroprevalence, associated risk factors and seasonal dynamics.

Acta Trop 2018 Dec 13;188:234-239. Epub 2018 Sep 13.

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

Q fever, caused by Coxiella burnetii, is a zoonotic disease responsible of abortion in ruminants. Few studies have investigated the prevalence of this infection in camels (Camelus dromedarius). The present report aimed to highlight the epidemiological status and identify the risk factors associated with C. burnetii infection in one-humped dromedary that is the most productive livestock species in arid areas. A total of 534 sera of healthy camels were collected in eight governorates from southern and central Tunisia. Samples were tested by an indirect Enzyme linked Immunosorbent Assay (ELISA). Results were analyzed using the Chi-square test and logistic regression. Overall, 237 camels (44%, 95%CI: 0.40-0.49) were seropositive to C. burnetii. Statistical analysis pointed out four potential risk factors associated with infection. A meaningful high seropositivity was observed in female camels with a previous history of abortion (70%) (OR = 4.186, 95%CI: 2.05-8.51). Seroprevalence was higher in aged camels (>10 years-old) (48%) (OR = 2.91, 95%CI: 1.37-6.17). Besides, camels, intended for meat production from small herds showed a high level of infection (52%) (OR = 2.43, 95%CI: 1.3-4.5). Coxiellosis evolved in dromedary herds throughout the year, however infection was significantly important in autumn (60%) (OR = 4.13, 95%CI: 1.86-9.17) and winter (56%) (OR = 5.52, 95%CI: 2.50-12.16). Bioclimatic stage, gender, tick infestation and contact with other ruminants were not risk factors in camel's infection by C. burnetii. Our reports confirm that Tunisian one-humped dromedaries had been exposed to this bacterium and could contribute to its dissemination among farmers and other livestock animals. Furthers studies are required to evaluate the prevalence of Q fever among people professionally exposed like farmers, veterinarians and slaughterhouse workers.
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http://dx.doi.org/10.1016/j.actatropica.2018.09.008DOI Listing
December 2018

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