Selection of <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> TN627 as a new probiotic candidate based on <Emphasis Type="Italic">in vitro</Emphasis> functional properties

Nine lactobacilli previously selected for high antagonism against food borne bacterial pathogens were identified via 16S rRNA gene sequencing and screened for probiotic potential for use in poultry production. The lactobacilli were subjected to a subtractive in vitro analysis system using a certified probiotic as reference. This allowed for selection of a milk-derived Lactobacillus plantarum strain, termed TN627. This organic acid-producing bacterium was free of harmful enzymatic activity and sensitive to several antibiotics. It also showed good growth at pH 4 and in the presence of bile. L. plantarum TN627 also exhibited high efficacy of adhesion to chicken enterocytes, which correlated with detecting genes encoding the mucusbinding, adhesion-promoting proteins (Mub and MapA) and the adhesion-like factor EF-Tu, commonly involved in adherence of lactobacilli to mucosal surfaces. Taken together, our findings suggest that TN627 is a promising probiotic candidate with high potential for application as a supplement in the animal feed industry.     

Molecular Genotyping of <Emphasis Type="Italic">Candida parapsilosis</Emphasis> Species Complex

Background

The Candida parapsilosis complex species has emerged as an important cause of human disease. The molecular identification of C. parapsilosis isolates at the species level can be helpful for epidemiological studies and then for the establishment of appropriate therapies and prophylactic measures.

Methods

The present study was undertaken to analyze 13 short tandem repeat (STR) markers (7 minisatellites and 6 microsatellites) in a global set of 182 C. parapsilosis complex isolates from different origins including invasive and superficial clinical sites.

Results

Upon the analysis of 182 strains of C. parapsilosis complex species, 10–17 haplotypes were detected for each minisatellite marker. The combination of 7 minisatellite markers yielded 121 different genotypes with a 0.995 D value. Upon the analysis of 114 isolates (68 from invasive infections and 46 from superficial infections), 21–32 genotypes were detected for each microsatellite marker. The combination of all 13 markers yielded 96 different genotypes among 114 isolates with a high degree of discrimination (0.997 D value).The same multilocus genotype was shared by isolates recovered from some patients and from the hand of theirs correspondent healthcare worker. For another patient, the same multilocus genotype of C. metapsilosis was detected in blood and skin confirming that candidemia usually arises as an endogenous infection following prior colonization.

Conclusions

These STR markers are a valuable tool for the differentiation of C. parapsilosis complex strains, to support epidemiological investigations especially studies of strain relatedness and pathways of transmission.

     

Reuse of Textile Wastewater after Treatment with Isolated Bacteria from Oued Hamdoun River

Industrialization is a boon for developing countries such as Tunisia. However, textile effluents that are being discharged are environmental pollutants, extremely toxic to plants and other living organisms, including humans. The current study was conducted to determine the phytotoxic effect of textile effluents, collected near an industrial zone in the center of Tunisia (Ksar Helal), on the germination and various growth indices of durum wheat (Triticumaestivum L.). Results showed that textile effluent treatments reduced significantly the percentage of seed germination and slowed its kinetic as compared with control. Roots and leaves were also significantly reduced. The phytotoxicity was highly reduced from textile effluents after aerobic biotreatment with bacteria. It can be concluded that the biological treatment process of textile wastewater might serve as a fertilizer production that is able to improve the growth of plants. These results are encouraging in the context of developing a low-budget technology for the effective management of these effluents.     

Traumatismes fermés des bourses: stratégie de prise en charge

Introduction

Blunt scrotal trauma is increasingly frequent, but surgical exploration of these cases of trauma remains controversial. The objectives of this study were to assess the diagnostic value of clinical examination and ultrasound in testicular trauma and to analyse the complications of the various treatments proposed (surgical and medical treatments), in order to more clearly define the place of medical or surgical treatment in this form of trauma in young adults.

Patients and Methods

130 cases of blunt scrotal trauma were managed between 1993 and 2004. In the absence of clinical and ultrasound criteria of severity (haematocele, very large intratesticular haematoma, rupture of the tunica albuginea), medical treatment consisting of rest, anti-inflammatory drugs, and testicular support was instituted. Surgical exploration was performed when serious lesions of the testis were suspected. Scrotal ultrasound was performed in 68 patients and 46 of them underwent scrotal exploration. The sensitivity and specificity of scrotal ultrasound were determined by comparing radiological findings with definitive intraoperative findings. The immediate morbidity and long-term sequelae were analysed.

Results

The mean age of the patients was 24 years (range: 4 to 73 years). The clinical features were dominated by pain (73.8%) and scrotal swelling (89.2%). The sensitivity of testicular ultrasound was 34.7% for testicular rupture, 100% for testicular contusions, 33.3% for intratesticular hematoma and 76.9% for haematocele. Medical and surgical treatments were instituted in 29.2% and 70.7% of cases, respectively. With a mean follow-up of 8 months, chronic pain and testicular atrophy were observed in 18% and 5.5% of cases, respectively.

Conclusion

In the absence of signs of severity, medical treatment with regular surveillance remains justified. However, in the presence of doubtful clinical or ultrasound findings, surgical exploration must be performed as soon as possible     

A potential role of TNFR gene polymorphisms in autoimmune thyroid diseases in the Tunisian population

Autoimmune thyroid diseases (AITDs) including Graves disease (GD) and autoimmune hypothyroidism (AH) are associated with TNF genes polymorphisms. TNF molecules bind to TNFRI and TNFRII. No genetic association was reported between TNFR and AITDs. In this study, we have analysed two polymorphisms in TNFRI gene (TNFRI+36A/G SNP and a microsatellite (GT)₁₇ (GA)_n) and one polymorphism in TNFRII gene (TNFRII +676 T/G). All these polymorphisms were studied in a large Tunisian family with high prevalence of AITDs, and on a case-control sample of 91 GD patients and 165 controls. The present study was undertaken to investigate the genetic association of these polymorphisms with AITDs development. We reported the implication of TNFRIA3 allele in AITDs pathogenesis in familial and case control studies, respectively (χ² = 4.13, p = 0.042; χ² = 9.26, p_c = 0.005). In addition, Case-control study has revealed for the first time that TNFRII+676G allele was associated with GD (χ² = 11.53; p = 0.0007). Two TNFRI haplotypes were found to be associated with GD: TNFRI+36G-A8, TNFRI+36A-A3 (χ² = 88.07; p = 6.32 × 10⁻²¹, χ² = 16.78; p = 4.2 × 10⁻⁵, respectively). Our data showed that TNFRI polymorphisms have an important role in AITDs pathogenesis in both familial and case-control samples and that TNFRII was rather implicated in GD development in the Tunisian population.     

Trans-glycosylation capacity of a highly glycosylated multi-specific β-glucosidase from Fusarium solani

An extracellular β-glucosidase from Fusaruim solani cultivated on wheat bran was purified by only two chromatographic steps. The purified enzyme exhibited optimal temperature and pH at 60 °C and pH 5, respectively. The purified β-glucosidase behaves as a very large protein due to its high degree of glycosylation. More interestingly, the endoglycosidase H (Endo H) treatment led to 97.55% loss of its initial activity after 24 h of treatment. Besides, the addition of Tunicamycin (nucleoside antibiotic blocking the N-glycosylation first step) during the culture of the fungus affected seriously the glycosylation of the enzyme. Both treatments (endo H and Tunicamycin) strengthened the idea that the hyperglycosylation is involved in the β-glucosidase activity and thermostability. This enzyme was also shown to belong to class III of β-glucosidases (multi-specific) since it was able to act on either cellobiose, gentiobiose or sophorose which are disaccharide composed of two units of d-glucose connected by β1–4, β1–6 and β1–2 linkage, respectively. The β-glucosidase activity was strongly enhanced by ferrous ion (Fe²⁺) and high ionic strength (1 M KCl). The purified enzyme exhibited an efficient transglycosylation capacity allowing the synthesis of cellotriose and cellotetraose using cellobiose as donor.

     

Quantification of pralidoxime methylsulfate (Contrathion) in human urine by capillary zone electrophoresis

Pralidoxime methylsulfate (Contrathion) is widely used to treat organophosphate poisoning. For the first time, we developed a specific assay for urinary pralidoxime using capillary zone electrophoresis (CZE) in the following conditions: fused-silica capillary (length: 47 cm, internal diameter: 75 microm), electrolyte solution: 25 mM sodium borate (pH 9.1), voltage: 15 kV, temperature: 25 degrees C, injection time: 1 or 2s, on-line UV detection: 280 nm. Sample preparation did not require a deproteinization step (1:5 dilution in water). The method was linear between 0.125 and 2 mg mL-1 of pralidoxime (quantification limit: 0.10 mg mL-1). Coefficients of variation for intra- and inter-assay precision were below 10% for all three control levels (0.15-1.15 mg mL-1). This assay was successfully applied to urine specimens from organophosphate poisoned patients treated by Contrathion (n=10). This CZE method allows the measure of pralidoxime in urine within 15 min with excellent precision, selectivity, and sensitivity. It is simple (no pretreatment) and convenient, thus suitable for the monitoring of Contrathion therapy in organophosphate poisoned patients.     

Interaction of intermittent fasting on the cytotoxic effects of nickel in rats at puberty

This study has been undertaken with the aim of determining if intermittent fasting can be considered as a malnutrition that amplifies, according to numerous authors, the cytotoxic effects of environmental pollutants. We have used 200 male and female rats of 'Wistar' descent (BW approximately 180 g). These rats are distributed into two groups: some nourished daily (N) and others nourished one day over two (J) during a month. By the end of this month, each group is itself split into two subgroups, the first one receiving tap water as drinkable water (group NO and JO); the other one receiving the water enriched by the chloride of nickel at the rate of 100 mg NiCl2 per litre (groups NNi and JNi). Intermittent fasting goes on parallel to treatment during 2, 4, 10, 16, 30 and 60 days. For the exploration of the protein of stress (HSP) and of the metallothioneines (MT), the nickel is administered by injection at the rate of 4 mg NiCl2 per kg during 1 and 5 days. Our results show that the mineral seric and renal balance does not vary in conditions of intermittent fasting compared with conditions of normal nutrition. Our study show than that nickel induced a renal deficiency by decreasing the creatinemia and uraemia rate, which is confirmed by the histological study, and induced a decrease in the induction of the HSP73 and in the synthesis of the (MT). The association of nickel with intermittent fasting would inhibit these effects. In conclusion, intermittent fasting does not manifest itself as a malnutrition that amplifies the nickel's effects. Nevertheless, it seems that the calorific lack provoked by intermittent fasting is beneficial to the body by increasing its performances against the cytotoxic effects induced by nickel.