Veterinary Research Institute of Tunisia

Tunis, Tunisia

Veterinary Research Institute of Tunisia

Tunis, Tunisia
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Ben Salem R.,Veterinary Research Institute of Tunisia | Ben Salem R.,University of Carthage | Abbassi M.S.,Veterinary Research Institute of Tunisia | Abbassi M.S.,University of Carthage | And 10 more authors.
Journal of Infection and Public Health | Year: 2017

This study focused on 77 isolates of Salmonella enterica serotype Enteritidis collected during 2009 to 2013 from healthy and sick chickens and environmental farm samples in Tunisia. Resistance to 14 antimicrobials and the encoding genes were analyzed. 66, 26, 6.5, 3.9 and 1.3% were pan-susceptible or showed resistance to nalidixic acid (Asp87 to Tyr and Asp87 to Asn substitutions in GyrA), ampicillin (bla TEM-1-like and bla SHV), sulfonamides (sul1and sul3) and streptomycin (strB), respectively. A single isolate with intermediate susceptibility to ciprofloxacin was positive for qnrB, whereas qnrA, qnrS or aac(6')-Ib-cr were not detected. The virulotype of the isolates was established by testing ten virulence genes. The orgA, ssaQ, mgtC, siiD, sopB genes, located on Salmonella pathogenicity islands, and spvC of the serotype-specific virulence plasmid, were common to all isolates. In contrast, the prophage-associated sopE-1, sodC1 and gipA genes and the fimbrial bcfC gene were variably represented. All isolates except one contained the virulence plasmid, which appeared either alone or together with one or more additional plasmids. One isolate carried a single plasmid of ca. 90Kb which may be derived from the virulence plasmid (60Kb). Overall, seven resistotypes, six virulotypes and six plasmid profiles were identified. XbaI-PFGE revealed four related pulsotypes (X1-X4), with 80% of the isolates sharing the X1 pattern. The latter isolates exhibited different resistance, virulence and plasmid profiles, suggesting that mobile genetic elements, particularly prophages and plasmids, are of central importance for the evolution and adaptation of S. Enteritidis circulating in chicken farms in Tunisia. © 2017 The Authors.


Ibrahim C.,Tunis el Manar University | Hammami S.,Manouba University | Mejri S.,Veterinary Research Institute of Tunisia | Pothier P.,University Hospital of Dijon
Microbial Pathogenesis | Year: 2017

Enteric viruses are released in important quantities into the environment where they can persist for a very long time. At very low doses, they can cause human gastroenteritis, and are responsible for a substantial number of waterborne diseases. The aims of this study were multiple: firstly, to study the circulation of Aichi viruses (AiV) in wastewater sampled at the scale of a pilot wastewater treatment plant; secondly, to evaluate the performance of two wastewater treatment procedures, as natural oxidizing lagoons and rotating Biodisks, concerning the AiV removal; and finally, to determine the different type of AiV genotype found during this study. Hence, the pilot wastewater treatment plant is principally irrigated by the wastewater of three neighbouring clinics. Wastewater samples were collected during 2011 from the two lines of biological treatment procedures. AiV detection in wastewater were achieved using the Reverse Transcription Polymerase Chain Reaction (RT-PCR) technique, and the identification of AiV genotype was realized by the direct sequencing of PCR products. The result revealed that AiV strains were identified in 50% (n = 51) of the wastewater samples. A significant increase of the AiV detection frequency was registered from upstream to downstream of the five ponds constituting the natural oxidizing lagoon process, and at the exit of the rotating Biodisks procedure. All detected AiV strains showed the highest nucleotide sequence identity to genotype B that has been recently observed in patients in Asia. This finding represented the first Tunisian survey that revealed and mentioned the first detection of AiV genotype B in sewage and by the same argued for a noticeable resistance or survival of this type of virus in the two lines of treatment considered. © 2017 Elsevier Ltd


Haddad-Boubaker S.,Veterinary Research Institute of Tunisia | Fakhfakh E.,Veterinary Research Institute of Tunisia | Megdich A.,Veterinary Research Institute of Tunisia | Ben Chehida N.,Veterinary Research Institute of Tunisia
Fish Pathology | Year: 2013

Lymphocystis disease virus (LCDV) causes a self-limiting disease in fish. However, recently, LCD outbreaks have increased, causing significant mortalities. In this study, we report the occurrence of two disease outbreaks in reared gilt-head sea bream Sparus aurata in the Tunisian coast. Presence of LCDV in diseased fish was confirmed by virus isolation using BF-2 cells and PCR amplification targeting the polymerase gene. Amino acid sequence analysis of the major capsid protein suggested that the LCDV strain was identical to nine strains previously isolated from the Mediterranean, Red Sea and South Atlantic coasts of Europe. These strains might have been disseminated through recent international trade.


Ben Salem R.,Veterinary Research Institute of Tunisia | Ben Salem R.,University of Carthage | Abbassi M.S.,Veterinary Research Institute of Tunisia | Garcia V.,University of Oviedo | And 3 more authors.
Zoonoses and Public Health | Year: 2016

Salmonella enterica subsp. enterica serovar Eppendorf, with antigenic formula 1,4,12,[27]:d:1,5, is an infrequent serovar. However, 14% (20 of 142) of the isolates recovered during June-July 2012 in chicken farms in Tunisia belonged to S. Eppendorf. These isolates were analysed for resistance and virulence profiles. None of them were susceptible to all antimicrobials tested, while 70%, 60%, 50%, 50%, 20% and 5% were resistant to sulphonamides (sul1, sul2 and sul3), streptomycin (aadA1-like), trimethoprim (dfrA1-like), nalidixic acid (GyrA Asp87→Asn and not identified), gentamicin (not identified) and ampicillin (blaTEM-1-like). About 30% of the isolates showed decreased susceptibility to ciprofloxacin and carried the qnrB gene 65% of the isolates were multidrug resistant and contained class 1 integrons with sul1 or sul3 in the 3' conserved segment. The orgA, ssaQ, mgtC, siiD and sopB virulence genes located on SPI1 to SPI5 and the fimbrial bcfC gene were present in all isolates; the sopE1 and sodC1 carried by prophages were variably detected; however, the prophage gipA gene and the spvC gene of serovar-specific virulence plasmids were absent. Altogether, ten resistance and three virulence profiles were identified. Typing of the isolates with XbaI- and BlnI-PFGE supports a close relationship, although they appear to be evolving under selective pressure probably caused by antimicrobial use in chicken husbandry. As far as we know, this is the first study investigating the molecular bases of antimicrobial drug resistance, the virulence gene content and the PFGE profiles of S. Eppendorf. The epidemiological surveillance of this serovar would be necessary to evaluate its possible impact on human health, particularly in Tunisia and other African countries where it was already reported. © 2016 Blackwell Verlag GmbH.


PubMed | Manouba University, Veterinary Research Institute of Tunisia and University of Oviedo
Type: Journal Article | Journal: Zoonoses and public health | Year: 2016

Salmonella enterica subsp. enterica serovar Eppendorf, with antigenic formula 1,4,12,[27]:d:1,5, is an infrequent serovar. However, 14% (20 of 142) of the isolates recovered during June-July 2012 in chicken farms in Tunisia belonged to S. Eppendorf. These isolates were analysed for resistance and virulence profiles. None of them were susceptible to all antimicrobials tested, while 70%, 60%, 50%, 50%, 20% and 5% were resistant to sulphonamides (sul1, sul2 and sul3), streptomycin (aadA1-like), trimethoprim (dfrA1-like), nalidixic acid (GyrA Asp87 Asn and not identified), gentamicin (not identified) and ampicillin (blaTEM -1-like). About 30% of the isolates showed decreased susceptibility to ciprofloxacin and carried the qnrB gene; 65% of the isolates were multidrug resistant and contained class 1 integrons with sul1 or sul3 in the 3 conserved segment. The orgA, ssaQ, mgtC, siiD and sopB virulence genes located on SPI1 to SPI5 and the fimbrial bcfC gene were present in all isolates; the sopE1 and sodC1 carried by prophages were variably detected; however, the prophage gipA gene and the spvC gene of serovar-specific virulence plasmids were absent. Altogether, ten resistance and three virulence profiles were identified. Typing of the isolates with XbaI- and BlnI-PFGE supports a close relationship, although they appear to be evolving under selective pressure probably caused by antimicrobial use in chicken husbandry. As far as we know, this is the first study investigating the molecular bases of antimicrobial drug resistance, the virulence gene content and the PFGE profiles of S. Eppendorf. The epidemiological surveillance of this serovar would be necessary to evaluate its possible impact on human health, particularly in Tunisia and other African countries where it was already reported.


Ben Kahla I.,Veterinary Research Institute of Tunisia | Ben Kahla I.,Microbiology and Immunology Laboratory | Boschiroli M.L.,Bacterial Zoonoses Unit Animal Health Laboratory French Agency for Food | Souissi F.,Veterinary Research Institute of Tunisia | And 4 more authors.
African Health Sciences | Year: 2011

Background: Consumption of raw milk and unpasteurized dairy products is common in Tunisia where bovine tuberculosis remains enzootic. We herein investigated the frequency of M. bovis isolation from raw milk. Methods: Three hundred and six milk samples collected from 102 infected cows in different Tunisian regions were analysed. M. bovis isolates were further characterized by spoligotyping and variable number tandem repeat typing. Results: A total of five (4.9%) M. bovis strains exhibiting three different genotypes were isolated. Conclusion: This study demonstrates that consumers of raw milk or derivatives in Tunisia are at high risk of zoonotic infection with M. bovis.


Haddad-Boubaker S.,Veterinary Research Institute of Tunisia | Boughdir W.,National Agronomic Institute of Tunisia | Sghaier S.,Veterinary Research Institute of Tunisia | Souissi J.B.,National Agronomic Institute of Tunisia | And 5 more authors.
Fish Pathology | Year: 2014

In this study, we report outbreak of viral nervous necrosis (VNN) in wild Epinephelus species, which are of an endangered fish group, in different Tunisian coastal areas in 2012. Seven fish of E. marginatus and E. costae caught at dead or moribund condition were investigated. Betanodavirus was detected in the brain and retinal tissues of all fish by RT-PCR and at high infective titers (106.0-8.8 TCID50/g) in five of seven fish. Sequence and phylogenic analyses of the viral genes revealed that the viruses belonged to RGNNV genotype and were closely related to some previously reported Mediterranean betanodavirus strains, suggesting virus exchanges among different fish populations in the Mediterranean Sea.


Thabet S.,Veterinary Research Institute of Tunisia | Souissi N.,Veterinary Research Institute of Tunisia
Molecular Biology Reports | Year: 2016

The mycobacterial insertion sequence IS6110 proved crucial in deciphering tuberculosis (TB) transmission dynamics. This sequence was also shown to play an important role in the pathogenicity (transmission ability and/or virulence) of Mycobacterium tuberculosis, the main causative agent of TB in humans. In this study, we explored the usefulness of IS6110 and its potential as a phylogenetic/typing marker. We also analyzed the genetic polymorphism and evolutionary trends (selective pressure) of its transposase-encoding open reading frames (ORFs), A and B, using the maximum likelihood method. Both ORFs evolved chronologically through random single nucleotide polymorphisms. They were subjected to strict purifying selection more tight on orfA, with no evidence of significant recombination events. OrfA proved to have a crucial role in regulating the transpositional process. Several analyses showed that IS6110 acquisition antedated the emergence of the Mycobacterium tuberculosis complex. This original copy of IS6110 element was functionally optimal. In conclusion, this study not only demonstrated the usefulness of IS6110 in terms of phylogenetic and typing purposes and its transpositional mechanism, but also informed the scientific community on its evolutionary history. © 2016 Springer Science+Business Media Dordrecht

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