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    Salah Hammami

    Epizootic haemorrhagic disease virus (EHDV) was detected for the first time in Tunisia and in other Northern African countries in 2006. The objective of the present study was to investigate whether EHDV circulated in Tunisian livestock... more
    Epizootic haemorrhagic disease virus (EHDV) was detected for the first time in Tunisia and in other Northern African countries in 2006. The objective of the present study was to investigate whether EHDV circulated in Tunisian livestock before and after the officially-reported outbreak of 2006. Thus, serum samples from cattle and dromedaries collected in different time periods (before and after 2006) and from different regions of Tunisia were screened for the presence of EHDV antibodies. Serological investigations conducted on cattle and dromedary sera collected in 2000 and 2001 demonstrated no virus circulation on these dates. However, viral circulation was evidenced in 2012 and 2013, although no EHDV cases were officially reported in these years. Serum-neutralization assessed on few ELISA positive samples, confirmed the presence of antibodies against EHDV serotype 6, which was the serotype involved in the EHDV outbreak in the Maghreb region in 2006.
    Bluetongue virus serotype 3 has been detected in a sheep in the Western part of the island of Sicily (Italy). This area is 150 km away from the peninsula of Cap Bon (Tunisia), where recent activities included in the Bluetongue National... more
    Bluetongue virus serotype 3 has been detected in a sheep in the Western part of the island of Sicily (Italy). This area is 150 km away from the peninsula of Cap Bon (Tunisia), where recent activities included in the Bluetongue National Surveillance plan demonstrated the widespread circulation of the same BTV strain.
    Bluetongue virus (BTV) and Epizootic haemorrhagic disease virus (EHDV) are double-stranded RNA orbiviruses of the Reoviridae family. Bluetongue virus and EHDV infect domestic and wild ruminants and they are transmitted by biting midges of... more
    Bluetongue virus (BTV) and Epizootic haemorrhagic disease virus (EHDV) are double-stranded RNA orbiviruses of the Reoviridae family. Bluetongue virus and EHDV infect domestic and wild ruminants and they are transmitted by biting midges of the genus Culicoides (Diptera: Ceratopogonidae). Since 1999, BTV outbreaks have occurred in Tunisia and 4 serotypes, BTV2, BTV1, BTV4 and BTV3, were involved in 2000, 2006, 2009, and 2016, respectively. Epizootic haemorrhagic disease was detected for the rst time in Tunisia and in other Northern African countries in 2006. These incursions have caused considerable economic losses. Our study had the goal to describe diversity, distribution, and seasonal dynamics of Culicoides. Fourteen sampling sites were chosen throughout the country and 2-night trapping of midges was performed monthly from June 2006 to July 2008. A total of 11,582 Culicoides specimens were collected from 336 light traps, comprising 25 species, of which 7 were identi ed for the rst ...
    In 2006, epizootic haemorrhagic disease (EHD) outbreaks were recorded in the Maghreb (Tunisia, Morocco and Algeria) among cattle, resulting in severe repercussions on herds (oedema of the head, necrotic lesions of the oral mucosa,... more
    In 2006, epizootic haemorrhagic disease (EHD) outbreaks were recorded in the Maghreb (Tunisia, Morocco and Algeria) among cattle, resulting in severe repercussions on herds (oedema of the head, necrotic lesions of the oral mucosa, hyperthermia of the teats, accompanied by anorexia and respiratory distress) and economic losses. The present study gives new information on the molecular characterisation of the EHD virus (EHDV) that had circulated in Tunisia. Genome segments 2, 3, 6, 7 and 10 of EHDV, corresponding to the VP2, VP3, VP5, VP7 and NS3/NS3A proteins, respectively, were amplified from the blood of one animal by RT-PCR and sequenced. Nucleotide sequence comparisons of these five segments with sequences available in the GenBank demonstrated that an EHDV serotype 6 (EHDV-6) had been present in Tunisia in 2006. The possible origin of this strain is discussed.
    Research Interests:
    The safety of the SAG2 rabies virus, a highly attenuated mutant of the SAD strain intended to vaccinate dogs by the oral route, was evaluated in local Tunisian dogs and in five other local species likely to consume vaccine baits. These... more
    The safety of the SAG2 rabies virus, a highly attenuated mutant of the SAD strain intended to vaccinate dogs by the oral route, was evaluated in local Tunisian dogs and in five other local species likely to consume vaccine baits. These species were the domestic cat (Felis catus), the jackal (Canis aureus), the jerboa (Jaculus orientalis), the merion (Meriones sp.) and the gerbil (Gerbillus campestris). The vaccine was administered orally to 21 dogs, 11 cats and eight jackals and orally or intramuscularly to 62 wild rodents of the above-mentioned species. Seven dogs, one cat, five jackals all juvenile and with poor health status) and two rodents died for intercurrent causes. The others were observed for 60-180 days. No animal showed any rabies symptom. Seroneutralizing antibodies were observed in all experimental groups, only after vaccination, with the highest rate being observed in jackals and rodents. The rabies virus was detected in the oral cavity of three cats 6 h after oral in...
    Background Toxoplasma gondii is an intracellular protozoan parasite that infects a wide variety of warm-blooded hosts, including humans. Limited information about T. gondii infection in bats is available in China. The objective of the... more
    Background Toxoplasma gondii is an intracellular protozoan parasite that infects a wide variety of warm-blooded hosts, including humans. Limited information about T. gondii infection in bats is available in China. The objective of the present study was to determine prevalence and genetic characterization of T. gondii infection in bats in Jilin, Liaoning, Jiangxi and Guangdong provinces, China.MethodsDuring May 2005 to August 2013, bats were sampled from Jilin, Liaoning, Jiangxi, and Guangdong provinces, China, and liver tissues were collected for the detection of T. gondii by a nested PCR targeting the B1 gene. The positive samples were genotyped at 11 genetic markers (SAG1, 5¿-and 3¿-SAG2, alternative SAG2, SAG3, BTUB, GRA6, L358, PK1, c22-8, c29-2, and Apico) using multilocus polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).ResultsA total of 626 bats representing 10 species were examined for T. gondii infection, 38 (6.1%) were tested positive with by P...
    ABSTRACT Chlamydiosis is a significant cause of abortion in goats and sheep in Tunisia. A new commercially available ELISA (ELISA-Chlamydophila abortus, ELISA-C. abortus) for detecting antibodies against C. abortus was evaluated using... more
    ABSTRACT Chlamydiosis is a significant cause of abortion in goats and sheep in Tunisia. A new commercially available ELISA (ELISA-Chlamydophila abortus, ELISA-C. abortus) for detecting antibodies against C. abortus was evaluated using field sheep and goat serum samples. This ELISA is based on a recombinant antigen that expresses part of a protein from 80 to 90kDa family that is specific to C. abortus. Serum samples collected from 219 sheep and 53 goats flock presenting abortion problems were used in this study. To assess the sensitivity of this new serological test, it was compared with the complement fixation test (CFT) using ELISA-antigen (Elisa-ag) detection and/or isolation as reference technique. Only 61.1% of the sera gave concordant results in both ELISA-C. abortus and CFT, and results were non-concordant for 22.4% due to 16.5% of doubtful results on CFT. The concordance of ELISA-C. abortus and Elisa-ag result was 65% while that of the CFT with ELISA-antigen was only 45%. This study using field material demonstrated that ELISA-C. abortus is a suitable method for diagnosis of chlamydiosis in order to implement early prophylactic measures from the first cases of abortion, both to stop the spread of infection and to prevent associated economic loss.
    The dsRNA concentrated polyacrylamide gel electrophoresis (CPAGE) detected rotavirus directly from 19% of 77 stool specimens from diarrheic calves. A commercial enzyme-linked immunosorbent assay (ELISA) detected 25%, latex agglutination... more
    The dsRNA concentrated polyacrylamide gel electrophoresis (CPAGE) detected rotavirus directly from 19% of 77 stool specimens from diarrheic calves. A commercial enzyme-linked immunosorbent assay (ELISA) detected 25%, latex agglutination test, 23%, and polyacrylamide gel electrophoresis (PAGE), 19%. Establishing CPAGE as the “standard,” the commercial ELISA and the latex agglutination test both had higher sensitivity (84%) than PAGE (79%). However, PAGE produced the highest specificity (100%), followed by agglutination (88%) and ELISA (84%). The commercial ELISA had a slightly higher sensitivity than agglutination, PAGE, and CPAGE, but the ELISA specificity was generally lower. The latex agglutination test had a lower sensitivity than ELISA, but specificity was higher. Agglutination had similar negative predictive values (94%), compared with agglutination and PAGE, but had the lowest positive predictive value (a measure of accuracy) (70%). Agreement with CPAGE was highest for PAGE (9...
    The double-stranded (ds) RNA genome segment 4 of bluetongue virus (BTV) serotype 2 was cloned and used as a serogroup-specific complementary (c) DNA probe for BTV diagnosis. A cDNA representing a 60% copy of genome segment 4 of BTV-2... more
    The double-stranded (ds) RNA genome segment 4 of bluetongue virus (BTV) serotype 2 was cloned and used as a serogroup-specific complementary (c) DNA probe for BTV diagnosis. A cDNA representing a 60% copy of genome segment 4 of BTV-2 prototype was produced. The specificity of the cDNA probe was determined by hybridizing this probe to a northern blot of dsRNA (separated by polyacrylamide gel electrophoresis) of plaque-purified BTV-2 prototype. This cDNA probe was then used to hybridize to the RNA samples. Because the probe hybridized to all BTV samples but not to epizootic hemorrhagic disease virus samples, it appears to be a group-specific probe that could be used in BTV diagnosis.
    The protective effect of the lyophilised SAG2 oral vaccine bait DBL2, already demonstrated on laboratory dogs, needed to be verified on common Tunisian dogs. Seven Tunisian dogs consumed totally or partially one DBL2 bait containing... more
    The protective effect of the lyophilised SAG2 oral vaccine bait DBL2, already demonstrated on laboratory dogs, needed to be verified on common Tunisian dogs. Seven Tunisian dogs consumed totally or partially one DBL2 bait containing 10(8.3) TCID50 of the highly attenuated rabies vaccine strain, SAG2. Five of the seven vaccinated animals survived a challenge administered 33 days later with a Tunisian canine street rabies virus to which five of the six controls that were not vaccinated and had no specific antibodies succumbed. The partial or total consumption of a single DBL2 bait thus conferred a protective immune response similar to that observed in laboratory dogs to dogs of poor health status. The sero-antibody response was, however, weak: only two vaccinated dogs exhibited a significant neutralising antibody response after vaccination and before the challenge, and four after the challenge.
    West Nile virus (WNV) is an arthropod borne virus of public health importance. The virus is a member of the genus Flavivirus and belongs to the Japanese encephalitis virus (JEV) antigenic complex under the Flaviviridae family. The WNV is... more
    West Nile virus (WNV) is an arthropod borne virus of public health importance. The virus is a member of the genus Flavivirus and belongs to the Japanese encephalitis virus (JEV) antigenic complex under the Flaviviridae family. The WNV is continuously spreading across Tunisia especially in the coastal and Southern area of the country. The first human West Nile disease (WND) epidemic in Tunisia occurred in 1997, since then, the quantity and the extension of spillover effects increased constantly. However, the existing knowledge of factors triggering such events continues to be rather poor. The last epidemic WNV human meningitis and meningoencephalitis recorded in 2012, with 86 cases and 6 deaths, confirmed the failure of the current system in predicting new cases. This review, based on analysis of scientific papers published between 1970 and 2015, summarises the state of knowledge on WNV in Tunisia and highlights the existing knowledge and research gaps that need to be addressed.
    L’élevage des petits ruminants est touché par plusieurs pathologies infectieuses cutanées. Ainsi, la clavelée et l’ecthyma contagieux représentent deux maladies virales importantes à étudier de part leur allure enzootique et la perte... more
    L’élevage des petits ruminants est touché par plusieurs pathologies infectieuses cutanées. Ainsi, la clavelée et l’ecthyma contagieux représentent deux maladies virales importantes à étudier de part leur allure enzootique et la perte économique qu’elles entraînent. L’objectif de ce travail a été l’isolement en Tunisie de souches virales responsables de ces deux pathologies cutanées et leur caractérisation par l’application et la comparaison de méthodes de diagnostic. La microscopie électronique a été utilisée pour une étude morphologique externe et interne des différentes souches isolées sur culture cellulaire. L’identification par PCR a concerné le gène de la thymidine kinase (TK), le gène de l’analogue du récepteur des chimiokines (CXCR-2) et le gène de la protéine P42K présente chez les Parapoxvirus. L’identification moléculaire très sensible et très spécifique des souches de Capripoxvirus a été complétée par une analyse phylogénétique.
    The genus Capripoxvirus within the family Poxviridae comprises three closely related viruses, namely goat pox, sheep pox and lumpy skin disease viruses. This nomenclature is based on the animal species from which the virus was first... more
    The genus Capripoxvirus within the family Poxviridae comprises three closely related viruses, namely goat pox, sheep pox and lumpy skin disease viruses. This nomenclature is based on the animal species from which the virus was first isolated, respectively, goat, sheep and cattle. Since capripoxviruses are serologically identical, their specific identification relies exclusively on the use of molecular tools. We describe here the suitability of the G-protein-coupled chemokine receptor (GPCR) gene for use in host-range grouping of capripoxviruses. The analysis of 58 capripoxviruses showed three tight genetic clusters consisting of goat pox, sheep pox and lumpy skin disease viruses. However, a few discrepancies exist with the classical virus–host origin nomenclature: a virus isolated from sheep is grouped in the goat poxvirus clade and vice versa. Intra-group diversity was further observed for the goat pox and lumpy skin disease virus isolates. Despite the presence of nine vaccine stra...
    La fièvre catarrhale du mouton a été déclarée en Tunisie en décembre 1999. D’autres cas de fièvre catarrhale du mouton ont également été répertoriés dans d’autres pays du bassin méditerranéen. L’objectif de cette étude a été, dans un... more
    La fièvre catarrhale du mouton a été déclarée en Tunisie en décembre 1999. D’autres cas de fièvre catarrhale du mouton ont également été répertoriés dans d’autres pays du bassin méditerranéen. L’objectif de cette étude a été, dans un premier temps, de caractériser les isolats viraux provenant de cette épizootie ayant sévi de décembre 1999 à mars 2000 et, dans un second temps, de déterminer l’origine du virus par phylogénie moléculaire. Pour se faire, les segments génomiques 2, 7 et 10 correspondant respectivement aux protéines VP2, VP7 et NS3/NS3A ont été amplifiés par PCR et séquencés. Des comparaison de séquences de ces différents segments génomiques issus des isolements viraux tunisiens ont pu êtres faits avec la souche virale sauvage et vaccinale corse ainsi que d’autres souches virales de fièvre catarrhale du mouton déjà publiées sur GenBank. Les résultats présentés sous forme d’arbres phylogénétiques et de tableaux de comparaisons de séquences nucléotidiques permettent de posi...
    A total of 118 sera were collected during 2016 from two groups of dromedaries from Kebili and Medenine governorates in the south of Tunisia. The aim of this study was to provide the first serological investigation of four emerging... more
    A total of 118 sera were collected during 2016 from two groups of dromedaries from Kebili and Medenine governorates in the south of Tunisia. The aim of this study was to provide the first serological investigation of four emerging vector-borne diseases in two groups of dromedaries in Tunisia. Sera were tested by ELISA and serum neutralisation test to identify West Nile virus (WNV), bluetongue virus (BTV), epizootic haemorrhagic disease virus (EHDV) and Rift Valley fever virus (RVFV). In the first group, the seroprevalence for BTV was 4.6%, while in the second group, it was 25.8% for WNV and 9.7% for BTV. Only serotype 1 was detected for BTV in the two groups. No evidence for circulation of RVF and EHD viruses was revealed. Results indicated that dromedaries can be infected with BTV and WNV, suggesting that this species might play a significant role in the epizootiology of these viral diseases in Tunisia and neighbouring countries.
    Among the 301 dogs vaccinated against rabies in a suburban area of Tunis, 165 were sero-surveyed for 13 months. One month after vaccination, 65% of the dogs less than 1 year of age and 76-84% of the older dogs had significant antibody... more
    Among the 301 dogs vaccinated against rabies in a suburban area of Tunis, 165 were sero-surveyed for 13 months. One month after vaccination, 65% of the dogs less than 1 year of age and 76-84% of the older dogs had significant antibody titers. One month after annual revaccination, these percentages ranged between 92% and 100%. Puppies (less than 3 months old) responded to vaccination with no significant interference by passive maternal immunity. Based on these percentages, a 93% rate of protection may be expected for vaccinated dogs. This study confirms that all dogs (even those less than 3 months of age) must be vaccinated during mass campaigns. The expected protection conferred by locally produced potent vaccines reaches 79-99% based on the age of the dogs. The alleged relative inability of local dogs to respond to vaccination cannot explain the partial success of rabies control in Tunisia.
    We evaluated a dog owner, participation-based, bait delivery system for the oral immunization of dogs against rabies. In a field study in a semirural area of northern Tunisia, dog owners were asked to come to temporary bait delivery... more
    We evaluated a dog owner, participation-based, bait delivery system for the oral immunization of dogs against rabies. In a field study in a semirural area of northern Tunisia, dog owners were asked to come to temporary bait delivery sites. A total of 314 baits were given to 178 dog owners in four sites. The experimental baits used consisted of a freeze-dried core unit containing sulfadimethoxine (SDM) as a biological marker and an aromatized paraffin envelope. No vaccine was used. Preliminary tests had shown that by using a rapid commercial card test, positive SDM serum levels were detected in more than 95% of dogs up to two days after bait ingestion. During the two days following bait delivery, we visited more than 95% of all households in the study area and took blood samples from as many owned dogs as possible. Unconsumed baits were recovered and human contacts with the bait matrix were recorded. The campaign required 7.6 person-min per bait and 13.5 person-min per dog owner for ...
    ... 2 Amelie Chadeyras,1 Elexpeter Aba Adulugba,3 Geneviève Libeau,1 * Salah Hammami,2 Adama Diallo4 and Emmanuel Albina1. ... specific attenuated or low-virulence capripoxvirus isolates to protect all three host species from capripox... more
    ... 2 Amelie Chadeyras,1 Elexpeter Aba Adulugba,3 Geneviève Libeau,1 * Salah Hammami,2 Adama Diallo4 and Emmanuel Albina1. ... specific attenuated or low-virulence capripoxvirus isolates to protect all three host species from capripox infection (Kitching, Hammond and Black ...
    The quality of animal products could be assessed based on certain intrinsic and extrinsic characteristics. It is nevertheless better reflected by consumers' perception, which, although different from the real and objective quality,... more
    The quality of animal products could be assessed based on certain intrinsic and extrinsic characteristics. It is nevertheless better reflected by consumers' perception, which, although different from the real and objective quality, determines the purchase of the product. Current trends following food illness outbreaks indicate that consumers are becoming more concerned about hygiene and quality. Based on this assertion this
    Viruses belonging to the Nodaviridae family cause disease worldwide among a large number of species of marine fish, and have been described in all continents. In the present study, a total of 69 farmed Tunisian sea bass (Dicentrarchus... more
    Viruses belonging to the Nodaviridae family cause disease worldwide among a large number of species of marine fish, and have been described in all continents. In the present study, a total of 69 farmed Tunisian sea bass (Dicentrarchus labrax) and 24 sea bream (Sparus aurata) samples were tested monthly for the detection of betanodavirus. The virus was identified in both species using indirect immunofluorescence assays (IFAT) and RT-PCR. In addition sequence analysis of part of the coat protein gene indicated that both species were infected by highly related, but distinct, strains belonging to the RGNNV genotype. The sequence of the coat protein gene of several strains was identical but up to 9 different sequences were detected in a single farm. In addition, viral sequences obtained from fish that were held at lower temperature (<20 degrees C) were distinct from the rest of the sequences.
    The efficacy of Chlamydophila abortus vaccine strain 1B in protecting against two selected Chlamydophila pecorum strains, isolated from an aborted goat (M14) in Morocco and a ewe (AB10) in France, was investigated in a mouse model, by... more
    The efficacy of Chlamydophila abortus vaccine strain 1B in protecting against two selected Chlamydophila pecorum strains, isolated from an aborted goat (M14) in Morocco and a ewe (AB10) in France, was investigated in a mouse model, by comparing the reduction in number of bacteria in the placentas of vaccinated mice challenged intraperitoneally at 11 days of pregnancy with the reference C. abortus (AB7) and C. pecorum (M14, or AB10) strains, to those of unvaccinated mice. Vaccine 1B was shown to provide effective protection against the field strains of C. pecorum, since it significantly reduced the placental Chlamydophila colonisation. The two C. pecorum strains were not sufficiently abortifacient in mice to use reduction in abortion as a criterion of protection.
    Two bait delivery systems for the oral immunization of dogs against rabies were tested in small scale field trials in a semi-rural area in Tunisia: bait delivery to owned dogs during door to door visits of households (door to door... more
    Two bait delivery systems for the oral immunization of dogs against rabies were tested in small scale field trials in a semi-rural area in Tunisia: bait delivery to owned dogs during door to door visits of households (door to door baiting) and distribution of baits on transect lines (transect line baiting). A prototype bait (DBL2) configured for industrial production and containing either sulfadimethoxine (SDM) as a systemic marker or Rhodamine B as a topical marker was used. The overall proportion of dogs which took a bait and presented topical marker staining after door to door baiting was 59.1%. The total time and costs spent per bait accepting dog averaged 34 person minutes and US$4, respectively. Unconsummated baits were readily recovered. No unprotected human contacts with baits were recorded. Door to door baiting is a very specific but time-consuming method that enables a safe administration of vaccine baits to owned dogs. For transect line baiting, baits were distributed at a density of ca 3000 baits per km2 along double transect lines. Baits were recovered after 20 h. According to the proportion of SDM positive serum samples, 24.1% of owned dogs in the baiting area had consumed baits. Of all owned and ownerless dogs, presumably free-roaming during transect line baiting, > 40% had consumed baits. The total time and costs spent per bait accepting dog averaged 48 person minutes and ca US$20, respectively. The household census revealed 32 direct human contacts with the bait matrix which corresponds to 1.4% of inhabitants. Placing baits on transect lines gives the possibility to vaccinate dogs not accessible by vaccination systems which base on dog owner participation. However, the method is not specific, less safe than other systems, not easily accepted by the human population, and costly.
    Integrons are important genetic elements implicated in acquisition and expression of antimicrobial resistance genes. Gene cassettes of class 1 integrons may be differently expressed depending on the Pc promoter variant. Thirty-four... more
    Integrons are important genetic elements implicated in acquisition and expression of antimicrobial resistance genes. Gene cassettes of class 1 integrons may be differently expressed depending on the Pc promoter variant. Thirty-four Escherichia coli isolates (carrying 38 class 1 integrons), recovered from poultry meat in previous studies in Tunisia and selected by their specific traits, were further characterized in this study. Integron promoter variants and the pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) of isolates were determined. Three types of promoter variants were identified among the 38 class 1 integrons (PcW, PcH1, and PcS); the weak promoters were the most predominant. A high clonal diversity of the E. coli strains was demonstrated by PFGE or by MLST. Fifteen PFGE profiles were detected among 19 integron-positive isolates of phylogroup B2, and 12 different sequence types were identified by MLST among the remaining 15 isolates (ST48, ST88, ST101, ST117, ST155, ST189, ST351, ST359, ST410, ST641, ST665, and one new ST). These data reflect that the presence of integrons in these isolates is not due to the clonal dispersion but to dissemination of genetic structures carrying integrons in different clones. To the best of our knowledge, this is the first report examining the gene cassette promoter variants in class 1 integrons of E. coli isolates from poultry meat origin. The predominance of promoters implicated in weak expression/high excision activity of gene cassette arrays is of interest because they could theoretically enhance the capacity of integrons to adapt to antibiotic pressure.