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R Azaiez

Publications and source records attributed to R Azaiez.

13 recordsLinked to original sources
PubMed2006

Genetic differences between Tunisian camel and sheep strains of the cestode Echinococcus granulosus revealed by SSCP.

Ovine and dromedary Echinococcus granulosus isolates from Tunisia were identified as G1 and G6 strains based on polymorphism of the mitochondrial cytochrome C oxydase CO1. Single strand conformation polymorphism (SSCP) was used in order to examine the genetic variation within and between Tunisian G1 and G6 strains and to estimate the extent of selfing. The dromedary isolates are genetically distinct from sheep isolates (high value of genetic variation between populations: Fst= 0.46). No significant deficiency in heterozygotes was found in sheep isolates, whereas heterozygote deficiency (suggesting selfing) was found in a limited number of camel isolates.

Animals↗
PubMed2005

Molecular evidence of ovine (G1) and camel (G6) strains of Echinococcus granulosus in Tunisia and putative role of cattle in human contamination.

Three hundred and seventy-two cysts coming from 50 humans, 166 cattle, 153 sheep and 3 camels were collected in order to establish some epidemiological molecular information in Tunisia for the first time. The analysis by PCR-RFLP of ITS1 sequence showed that all the human, ovine and bovine cysts were due to the common sheep strain of Echinococcus granulosus. The sequencing of the CO1 gene of 37 isolates confirm the G1 genotype of this strain. For seven of these isolates, we found the mutation C56T which is present in the three principal intermediate hosts: human (three cysts), cattle (three cysts) and sheep (one cyst). With regard to the G1 genotype, we identified three other point mutations. The camel strain G6 is uniquely found in the three camels isolates and not in the other intermediate hosts analysed. The fertility of the bovine cyst represents 48% that means that this host is involved in a bovine-dog cycle and consequently represents a reservoir of sheep strain in Tunisia. Our results confirm the importance of the prophylaxis measures in order to disrupt the cycle of transmission sheep-dog in Tunisia. Nevertheless, the supervision of bovine infection should be reinforced because this intermediate host may constitute an important link with the human contamination.

Animals↗
PubMed2005

Anthroponotic cutaneous leishmaniasis in Tunisia: presence of Leishmania killicki outside its original focus of Tataouine.

The first three documented cases of anthroponotic cutaneous leishmaniasis due to Leishmania killicki are reported from locations outside the original focus of Tataouine in southeast Tunisia. Three strains were isolated from three patients from Gafsa, Sidi Bouzid and Seliana indicating an extension of this parasite's range towards the centre and the north of Tunisia.

Adolescent↗
PubMed2005

Usefulness of PCR in the diagnosis of cutaneous leishmaniasis in Tunisia.

We assessed the efficiency of a PCR method in establishing the diagnosis of cutaneous leishmaniasis (CL) in Tunisian patients. Four hundred and thirty specimens collected passively from patients with cutaneous ulcers suggestive of leishmaniasis attending health centres for diagnosis were included in the study. Dermal scrapings were analysed both by parasitological (examination of Giemsa-stained smears and in vitro cultivation) methods and by a genus-specific PCR detecting a fragment of the 18S rRNA gene. Microscopy revealed amastigotes in 245 samples (57.0%) and in vitro cultivation gave positive results in 88 cases (20.5%), whereas PCR detected Leishmania in 301 samples (70%). The sensitivities inferred from our results were 99.3%, 80.8% and 29% for PCR, microscopic examination and in vitro cultivation, respectively. The different forms of CL in this country are caused by three species of Leishmania and are treated with the same protocol. Of 303 well-documented cases in our study, 99% were probably caused by Leishmania major and 1% by Leishmania infantum. The lack of species-specific diagnosis is not known to affect treatment or prognosis in Tunisia. These data support the incorporation of PCR into diagnostic strategies for CL, particularly in Tunisia.

Animals↗
PubMed2004

Genetic relationships between sheep, cattle and human Echinococcus infection in Tunisia.

Allozyme variation at seven polymorphic loci (GPI, EST, MDH, MPI, DIA, PEP, PGM) was studied to examine genetic variation within and between sheep, cattle and human populations of Echinococcus granulosus in Tunisia. A high degree of genetic similarity was shown between the cysts of the three host origins. Nevertheless, whereas, the ovine and human samples were highly similar, the cattle samples were slightly different genetically. We conclude that humans are mostly infected by parasites originating from sheep liver. The intense deficiency in heterozygotes was partly artefactual (Wahlund effect) and partly due to self-fertilisation.

Adolescent↗
PubMed2003

Glutathione S-transferases (GSTT1 and GSTM1) gene deletions in Tunisians: susceptibility and prognostic implications in breast carcinoma.

Glutathione S-transferase Theta1 and Mu1 (GSTT1 and GSTM1) are involved in the metabolism and detoxification of a wide range of potential environmental carcinogens. Conversely, they contribute to tumour cell survival by detoxification of numerous products induced by cancer therapy. The authors designed a large study to investigate the susceptibility and prognostic implications of the GSTT1 and GSTM1 gene deletions in breast carcinoma. The authors used the polymerase chain reaction to characterise the variation of the GSTT1 and GSTM1 genes in 309 unrelated Tunisian patients with breast carcinoma and 242 healthy control subjects. Associations of the clinic-pathologic parameters and the genetic markers with the rates of the breast carcinoma specific overall survival (OVS) and the disease-free survival (DFS) were assessed using univariate and multivariate analyses. A significant association was found between gene deletion of GSTT1 and the risk of early onset of breast carcinoma (OR=1.60, P=0.02). The lack of GSTT1 gene deletion was significantly associated with poor clinical response to chemotherapy (OR=2.29, P=0.03). This association was significantly higher in patients with axillary's lymph node-negative breast carcinoma (OR=12.60, P=0.005). The null-GSTT1 genotype showed a significant association with increased DFS in this selected population of patients. This association was even higher in patients carrying both null-GSTT1 and -GSTM1 genotypes. The gene deletion of GSTs may predict not only the early onset of breast carcinoma but also the clinical response to chemotherapy and the recurrence-free survival for patients with lymph node-negative breast carcinoma.

Adult↗
PubMed2001

[Visceral leishmaniasis in immunocompetent children: diagnostic and epidemiologic value of peripheral leishmania blood culture].

Utilisation of new diagnosis means and particularly non invasive oues in visceral leishmaniasis can be very valuable for the biologist, the clinician as well as the patient. In this, detection of leishmania in peripheral blood, well know for VIH patients, has been applied to 37 immunocompetent tunisan children suffering from kala azar that has been shown through direct examination of bone marrow. Observed results show that culture on NNN peripheral blood medium was positive in 25 cases (67.57%). On the other side, detection of leishmania through concomitant culture of blood and marrow bone for 24 children with visceral leishmaniasis match the results in 75% of the cases. Detection of leishmania by mean of blood culture for immunocompetent children is a diagnosis mean of visceral leishmaniasis and has also an epidemiologic utility by isoenzymatic characterization of isolated leishmania strains.

Animals↗
PubMed2000

[Infantile visceral leishmaniasis from Leishmania infantum MON-24: a reality in Tunisia].

The authors report the first documented observation of infantile visceral leishmaniasis due to Leishmania infantum MON-24 zymodeme in Tunisia. This zymodeme was isolated from a non-immunodepressed two-year-old child, with visceral leishmaniasis, originating from Zaghouan, in northern Tunisia. This case shows that beside L. infantum MON-1 and MON-80, L. infantum MON-24, the usual parasite of cutaneous leishmaniasis, there exists also a causative agent of visceral leishmaniasis in our country.

Animals↗
PubMed1993

Isolation and characterization of a repetitive DNA sequence from Leishmania infantum: development of a visceral leishmaniasis polymerase chain reaction.

To construct a DNA probe specific for protozoa that cause visceral leishmaniasis, we cloned Pst I fragments of Leishmania infantum genomic DNA into a Bluescript II SK vector. A clone of 4.3 kb that contained a highly repetitive sequence was isolated and cut with three restriction enzymes: Hae III, Rsa I, and Sau 3A. After a new molecular cloning step, we isolated and sequenced a 140-basepair (bp) fragment. Two oligonucleotides were synthesized to be used as primers for a polymerase chain reaction. Using this probe, we detected an amount of DNA equivalent to one promastigote of L. infantum. This probe showed a high specificity; all protozoa tested that cause visceral leishmaniasis and L. major (one of the causative agents of Old World cutaneous leishmaniasis) showed a 100-bp amplified sequence, whereas other Leishmania strains showed a signal of a different size or else no signal. Moreover, no amplified sequence was obtained with other pathogenic parasites tested (Trypanosoma brucei, T. cruzi, Plasmodium falciparum, Pneumocystis carinii, and Toxoplasma gondii).

Animals↗
PubMedDate not supplied

Visceral leishmaniasis in Tunisia: result of the isoenzymatic characterization of 65 Leishmania infantum strains.

The isoenzymatic characterization of 65 Tunisian strains of Leishmania, isolated from human cases of visceral leishmaniasis between June 1998 and August 2001, revealed the existence of 3 zymodemes of the L. infantum complex: MON-1 the most common (93.8%), followed by MON-24 (3.1%) and MON-80 (3.1%). 72% of the strains were obtained from children under the age of 5 years. The majority of the studied strains originated from 8 provinces of northern Tunisia, particularly the province of Zaghouan.

Animals↗