Characterization of Tunisian Mycobacterium tuberculosis rifampin-resistant clinical isolates

Analysis of the gene encoding the beta-subunit of Mycobacterium tuberculosis RNA polymerase (rpoB) has demonstrated a small region that harbors the mutations most frequently associated with rifampin resistance. In this study, we determined the occurrence of rifampin resistance in 544 Tunisian clinical M. tuberculosis strains isolated in a university hospital between 2004 and 2006 by using the standard-proportion agar method, the INNO-LiPA Rif.TB assay, and DNA sequencing.     

The Role of Dietary Intake in Type 2 Diabetes Mellitus: Importance of Macro and Micronutrients in Glucose Homeostasis

The prevalence of Type 2 diabetes (T2D) is increasing worldwide. Genetics and lifestyle, especially diet, are contributing factors. Analyses of macro- and micronutrient intake across global populations may help to explain their impact on glucose homeostasis and disease development. To this end, 420 Tunisians were enrolled in a prospective cross-sectional study of daily food consumption. Various data were collected and blood samples were drawn for biochemical assay. A 24-h recall questionnaire was obtained from participants to evaluate dietary intake. Statistical analyses were conducted using Nutrilog and R software. Biochemical analyses stratified the studied population (n = 371) into three groups: diabetics (n = 106), prediabetics (n = 192) and controls (n = 73); 49 subjects were excluded. Our results showed that Tunisians had hypercaloric diets high in carbohydrates and fat with variability in the levels of some vitamins and minerals, including riboflavin and niacin, that were statistically different among groups. The lower intake of vitamin D was associated with a greater risk of T2D. Higher vitamin A and sodium intake were associated with poor glucose homeostasis, although protein intake may improve it. In perspective, nutrigenomic studies can provide insight into problematic diets and poor eating habits and offer opportunities to analyze the effects of behavioral changes that can mitigate T2D development and progression.     

Combined Effects of the C161T and Pro12Ala PPARγ2 Gene Variants with Insulin Resistance on Metabolic Syndrome: A Case–Control Study of a Central Tunisian Population

We investigated the synergism between variants at the PPARγ locus (C161T and Pro12Ala polymorphisms) with insulin resistance on metabolic syndrome (MS). Five hundred twenty-two subjects were investigated for biochemical and anthropometric measurements. The diagnosis of MS was based on the IDF definition (2009). The HOMA 2 was used to determine HOMA-β, HOMA-S, and HOMA-IR from FPG and FPI concentrations. PCR-RFLP was performed for DNA genotyping. We showed that carriers of the Pro/Pro had a significantly higher FPG, FPI, and HOMA-IR. In addition, Pro/Pro subjects also display reduced HOMA-β and HOMA-S together compared to X/Ala (Pro/Ala and Ala/Ala) subjects. Furthermore, subjects with C/C have a significantly lower FPG, FPI, and HOMA-IR and higher HOMA-S compared to X/T (C/T and T/T) subjects. The C/C genotype carriers with an Ala allele group had significantly reduced FPG, FPI, HOMA-IR, and TG and elevated HOMA-S and HOMA-β than the different genotype combinations. We suggest that the haplotype composed of the C/C genotype carriers with an Ala allele of PPARγ2 group enhances susceptibility to the MS in a central Tunisian population.     

Étude de l’auto-immunité chez des patients tunisiens adultes atteints de maladie cœliaque : résultats d’une étude prospective comparative

Aim

To determine the frequency of autoantibodies in patients with celiac disease and identify factors associated with the higher prevalence of autoimmunity in these patients.

Materials and methods

We conducted a prospective study involving 50 adult patients with celiac disease and 50 healthy controls. We systematically searched for the presence of the following autoantibodies: antinuclear, anti-smooth muscle, anti-keratin, anti-islet-cell, anti-DNA, rheumatoid factor, thyroid peroxydase, thyroglobulin and glutamate decarboxylase.

Results

At least one autoantibody was detected in 88% of the patients and 54% of controls (p = 0.0001). In patients with celiac disease, we found a higher prevalence of the following antibodies: antinuclear (44 vs 16%; p = 0.002), anti-ENA (22 vs 2%; p = 0.01), rheumatoid factor (42 vs 15%; p = 0.008) and anti-islet-cell (12 vs 0%; p = 0.01). Factors associated with the presence of anti-thyroid antibodies were older age (37.3 ± 5.7 vs 30.3 ± 9.3 years; p = 0.005) and the lack of IgA anti-gliadin antibodies (37 vs 76%; p = 0.04). Factors associated with the presence of islet-cell antibodies were younger age (22.5 ± 5.7 vs 30.3 ± 9.3 years; p = 0.005) and male gender (67 vs 14%; p = 0.01).

Conclusion

Autoimmunity is frequent in celiac disease. Autoantibodies should be useful in screening for several autoimmune diseases, particularly thyroid disorders and diabetes.