[Contribution of the genetic fingerprintings compared to grouping ABO/Rhesus technique in the expertise of filiation]. / Apport des empreintes génétiques par rapport à la technique de groupage ABO/Rhésus dans l'expertise de filiation.

Paternity is based on biological analyzes that have drastically developed during the past 20 years. According to scientific developments, paternity testing was based on red blood groups studies, the analysis of red cell enzymes and plasma proteins polymorphisms, the typing of the HLA antigens, and the DNA polymorphism in its various forms. This study aims at comparing two analyses: red blood groups and DNA polymorphism. The performance of each test is analyzed in this report, based on a study of 142 cases. Indeed, the numbers of case of paternity exclusion are respectively 6 and 45 by the classic method and the genetic one. Thanks to studies based on the gene amplification of microsatellites, the efficiency of this reference technique has been proved, however, the classic one makes it possible in the cases of exclusion to lead to a certain decision without recourse to other systems. Of these facts, beyond the most efficient biological analysis, it is very important to think about paternity testing as a process in which biological tests are only one step.

Detection of icaA and icaD loci by polymerase chain reaction and biofilm formation by Staphylococcus epidermidis isolated from dialysate and needles in a dialysis unit.

Staphylococcus epidermidis, a coagulase-negative staphylococcus, is a major cause of infections associated with indwelling medical devices. Certain strains produce slime and form biofilm on polymer surfaces, where their pathogenicity is associated with biofilm formation. In this report, we investigated the presence or absence of the intercellular adhesion icaA and icaD genes by polymerase chain reaction, and phenotypic biofilm production was examined by qualitative Congo red agar (CRA) assay. A total of 32 strains of S. epidermidis were identified from dialysates and needles 4h after the initiation of dialysis. Qualitative biofilm production revealed that 16 (50%) strains produced slime on CRA plates. Among the 23 strains positive for the ica operon, 15 were biofilm positive on CRA, eight were biofilm negative, and one was icaA and icaD negative but produced slime. These results show that the ability of S. epidermidis to produce slime is not associated with the presence of icaA and icaD genes.

[Prevalence and characterization of uropathogenic Escherichia coli producing cytotoxic necrotizing factor type 1 (CNF1) in the center of Tunisia]. / Prévalence et caractérisation des Escherichia coli uropathogènes producteurs de facteur cytotoxique nécrosant type 1 (CNF1) dans le centre de la Tunisie.

During a three-year survey of the prevalence in central Tunisia of Escherichia coli producing CNF1 toxin (NTEC), 716 samples have been investigated by PCR for cnf1 gene. All samples were isolated from urine of adult and children patients presenting significant bacteriuria (> 10(5) colony-forming units/mL), independently of the severity of the clinical presentation; 328 strains were found harboring cnf1 gene, they were distributed into three clinical categories: 219 (66.76%) from patients with symptomatic bacteriuria, 76 (23.17%) from patients with uncomplicated cystitis and 33 (10.06%) from patients with acute pyelonephritis and complicated urinary tract infections. 98.78% (324) of CNF1 strains presented hemolytic activity. All 328 CNF1 strains harbored both sfa and pap genes and expressed MRHA activity. They belonged to 16 different serotypes. The most common serotypes, in order of frequency, were O6 (25.91%), O4 (17.98%), O2 (12.5%), O75 (9.14%), O78 (8.35%), and O83 (3.65%). Two strains (0.6%) were O168; a serotype shown to be associated to CNF2 producing bovine strains. The frequency of uropathogenic CNF1 strains in center Tunisia was about 45.81% and increased from 26.08% in 1998 to 58.16% in 2000. We showed that E. coli producing cytotoxic necrotizing factor (CNF1) was implicated in urinary tract infections in center Tunisia but no difference was shown between strains isolated from patients with complicated or uncomplicated urinary tract infections. The presence of CNF1 toxin with various associated virulence factors seemed to increase the risk for severe forms of urinary tract infections.

[The estimation of fibrinogen by kinetic immunonephalometry]. / Dosage du fibrinogène par immunonéphélométrie cinétique.

A new immunonephelometric micromethod for the estimation of fibrinogen is described. The reaction, linear between 0.30 g/l and 11 g/l requires only 5 microliters of plasma. The precision and sensitivity of the method are satisfactory. Comparisons with the chronometric technique of Clauss and with the Mancini immunodiffusion technique were made.

[Telomeres and telomerase as targeted therapies in cancer treatment]. / Télomères et télomérase comme cibles thérapeutiques dans le traitement du cancer.

Advances in chromosome dynamics have increased our understanding of the significant role of telomeres and telomerase in cancer. Telomerase is expressed in almost all cancer cells but is inactive in most normal somatic cells. Therefore, telomerase is an important target for the design of therapeutic agents that might have minimal side effects. Herein, we evaluate current approaches to telomerase/telomere-targeted therapy, discuss the benefits and disadvantages, and speculate on the future direction of telomerase inhibitors as cancer therapeutics.

Multiplex PCR detection of the antibiotic resistance genes in Staphylococcus aureus strains isolated from auricular infections.

Thirty-five Staphylococcus aureus strains from auricular infections were isolated. The identification of strains was confirmed by Api ID 32 Staph strips, the antibiotic susceptibility test was performed using ATB Staph kit. PCR assay was used to detect the oxacillin resistance gene (mecA) and the erythromycin genes (ermA, ermB, ermC, msrA and mef). The susceptibility profile of all strains revealed a low resistance level to oxacillin and erythromycin. The PCR results show that 60 % of the strains are mecA positive. The frequency of erythromycin genes was: ermA (+) 22.8 %, ermB (+) 45.7, ermC (+) 17.1, msrA (+) 28.6. The mef gene was not detected in any strain. No correlations between genotypic and phenotypic methods for the determination of oxacillin and erythromycin resistance was found. However, multiplex PCR technique was shown to be a fast, practical and economic technique for the detection of methicillin-and erythromycin-resistant staphylococci.

Alpha 1 antitrypsin polymorphism in the Tunisian population with special reference to pulmonary disease.

OBJECTIVES: The study investigated alpha 1 antitrypsin (AAT) gene polymorphism in the Tunisian population. We aimed to analyze the correlation between Pi polymorphism and the risk of developing chronic obstructive pulmonary disease (COPD). PATIENTS AND METHODS: We focused our study on two samples originating from the Tunisian centre: 318 healthy controls and 90 patients suffering from COPD. Data analysis was investigated by AAT level quantification, serum isoelectric focusing (IEF) and RFLP-PCR performed with PiS and PiZ allele specific primers. RESULTS: We calculated PiM1, PiM2, PiM3, PiS and PiZ allele frequencies in patients and controls. The difference in allele frequencies is significant only for the PiM2 allele (P=0.00378). In COPD patients, we note the presence of PiZ allele. This allele mainly observed in European populations, is rare in sub-Saharian populations and not described in North Africa. CONCLUSION: PiZ allele is found in COPD sample and never in Tunisian controls. However, no significant difference in PiZ allele frequency between patients and controls can be concluded. PiM2 allele, which is considered as "normal" variant can be associated with COPD risk.