Evaluation of an immunochromatographic assay for rapid identification of Mycobacterium tuberculosis complex in clinical isolates

Identification of Mycobacterium tuberculosis complex (MTC) remains slow. Over the years, several new technologies have been proposed to accelerate and simplify the detection of MTC. In this context, we evaluated an immunochromatographic assay (ICA) (BIO-LINE SD Ag MPT64 TB) for rapid identification of MTC, based on detection of a specific MPT64 antigen of MTC. We have tested it on i) mycobacterial cultures: 210 MTC strains and 28 nontuberculous mycobacteria; ii) M. bovis bacille Calmette-Guérin strain SSI (Statens Serum Institut, Denmark); and iii) 22 microorganisms other than mycobacteria, isolated from cultures. We concluded that this kit has an excellent specificity (100%) and sensitivity (99%) from isolated cultures. The ICA (BIO-LINE SD Ag MPT64 TB) allows excellent MTC identification from clinical isolates. It is a rapid, simple, and inexpensive test, and has a definite contribution in the rapid laboratory diagnosis of tuberculosis.     

Allele frequencies and population data for 17 Y-STR loci (The AmpFlSTR® Y-filer™) in Casablanca resident population

Allele frequencies and population data for 17 Y-STR loci included in the AmpFlSTR? Y-filer? PCR amplification kit (Applied Biosystems, Foster City, USA), that permit the simultaneous amplification of all the markers included in the actually used European "extended haplotype", DYS19, DYS189I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385I/II, DYS438, DYS439 and also DYS437, DYS448, DYS456, DYS458, DYS635 and Y GATA H4, were obtained from a sample of 166 healthy unrelated males resident in Casablanca (from Morocco). A total of 166 haplotypes were identified, of which 142 were unique. The overall haplotype diversity for the 17 Y-STR loci reached 0.9974, and a discrimination capacity was 0.855. We report some non-standard situations, including duplications and microvariant alleles.     

Infection par le virus de la chorioméningite lymphocytaire et fœtopathies

Objective

Lymphocytic choriomeningitis virus (LCMV), a rodent-borne arenavirus, is an uncommonly recognized cause of severe congenital viral infection. The incidence of this infection during pregnancy is still unknown. Our study aimed to evaluate LCMV infection frequency in pregnancy with fetal neurological abnormalities of unknown etiology.

Material and methods

Samples obtained during three years from 160 pregnant women were retrospectively analysed: 155 maternal sera, 150 amniotic fluids (AF) and 12 fetal sera (FS). Congenital neurological anomalies were diagnosed but TORCH and culture investigations were negatives. Serological analysis was performed with L929 cells infected with the Armstrong strain of LCMV. IgG and IgM antibodies against CMLV were researched by immunofluorescence assay using these infected cells. Interferon alpha was also assayed for AF and FS.

Results

No positive serology was found in any of the 317 samples investigated even when interferon alpha was detected.

Conclusion

This result confirms the rarity of LCMV infection in France. Nevertheless, at the light of the recent literature, this teratogenic pathogen should be considered in pregnancy with unexplained congenital malformation, especially after rodent exposure.     

Séroépidémiologie de la rubéole, de la varicelle et des infections par le cytomégalovirus et le parvovirus B19 chez les femmes enceintes dans la région de Sousse, Tunisie

The aim of the study is to evaluate seroprevalence of rubella virus (RV), cytomegalovirus (CMV), varicella zoster virus (VZV), and parvovirus B19 (PB19) in 404 Tunisian pregnant women, and to determine reliability of maternal past history of eruption. Sociodemographic characteristics, risk factors, and past history of eruption were collected through a questionnaire. Serologic tests were performed using enzyme immunoassays. Risk factors were analyzed using univariate and multivariate logistic regression models. Seroprevalences were 79.7% for rubella, 96.3% for CMV, 80.9% for VZV, and 76.2% for PB19. In multivariate analysis, the number of persons per room (> 2) in the house during childhood was associated with CMV infection (P = 0.004), irregular professional husband's activity was correlated with VZV infection (P = 0.04), and an age of more than 30 years was associated with PB19 infection (P = 0.02). History of rubella, varicella, and PB19 infection was unknown for, respectively, 55.8%, 20%, and 100% of women. False history of rubella and varicella were found for 7.4% and 15% of women, respectively. The positive and negative predictive values (PPV and NPV) of rubella history were, respectively, 92.6% and 17.2%, and were, respectively, 84.9% and 20.9% for varicella history. Susceptibility to RV, VZV, and PB19 infection remains high in pregnancy in our population. Preventive strategies against congenital rubella must be reinforced. Vaccination against VZV should be considered in seronegative women. Systemic CMV screening is not warranted in our country where high immunity is acquired probably in childhood. Since maternal history of eruption is not reliable, we recommend serologic testing to determine immune status of women.     

Mosaic trisomy 16 in a fetus: the complex relationship between phenotype and genetic mechanisms

OBJECTIVES: This study was undertaken to discuss the workup of trisomy 16 pregnancies. STUDY DESIGN: This case study reports the prenatal detection and postnatal confirmation of mosaic trisomy 16, associated with uniparental disomy (UPD) 16, in a 34-year-old woman who showed elevated maternal serum alpha-fetoprotein and beta-HCG at a gestational age (GA) of 15.5 weeks. RESULTS: Amniotic fluid (AF) karyotyping at different GAs revealed various levels of trisomy 16 mosaicism (0 to level III). UPD studies at 21 weeks of gestation revealed maternal heterodisomy 16. Serial fetal ultrasonography showed fetal abnormalities: intrauterine growth restriction (IUGR), dilated digestive tract, and gallbladder agenesis. Postmortem examination confirmed the prenatal findings and revealed additional anomalies, such as hypoplastic cerebellum with abnormal gyration of the vermis. CONCLUSIONS: Workup following prenatal detection of trisomy 16 mosaicism in chorionic villi must include AF karyotyping and serial ultrasound examination of the fetus in order to approach postnatal developmental prognosis.     

Increased levels of soluble HLA‐G molecules in Tunisian patients with chronic hepatitis B infection

Hepatitis B virus (HBV) infection is a global health problem. The mechanisms of immune tolerance in HBV infection are still unclear. The host immune response plays a critical role in determining the outcome of HBV infection. Human leucocyte antigen‐G (HLA‐G) is involved in immunotolerogenic process and infectious diseases. This study aimed to explore the implication of soluble HLA‐G (sHLA‐G) and its isoforms in HBV infection. Total sHLA‐G (including shedding HLA‐G1 and HLA‐G5) was analysed by ELISA in 95 chronic HBV patients, 83 spontaneously resolvers and 100 healthy controls (HC). To explore the presence of sHLA‐G dimers, we performed an immunoprecipitation and a Western blot analysis on positive samples for sHLA‐G in ELISA. The serum levels of sHLA‐G were significantly increased in patients with chronic HBV patients compared to spontaneously resolvers and HC (P<.0001). Interestingly, we found an increased level of sHLA‐G1 in chronic HBV patients than in spontaneously resolvers and HC (P<.001). In addition, the expression of HLA‐G5 seems to be higher in the sera of chronic HBV patients than spontaneously resolvers (P=.026). The analysis of HLA‐G dimers showed the presence of homodimers in 93% of chronic HBV patients, 67% in spontaneously resolvers and 60% in HC. These results provide evidence that sHLA‐G may have a crucial role in the outcome of HBV infection and could be proposed as a biomarker for infection outcome. Based on its tolerogenic function, HLA‐G might be considered as a new promising immunotherapeutic approach to treat the chronic infection with HBV.     

Cholestasis caused by a choledochal botryoid rhabdomyosarcoma in a 22-month-old boy

Botrioid rhabdomyosarcoma of the extrahepatic bile ducts is a rare cause of jaundice in children. It has a very poor prognosis and is rarely diagnosed preoperatively. We report a choledochal botrioid rhabdomyosarcoma in a 22-month-old boy who developed an obstructive jaundice. Radiographic explorations suggested cystic lymphangioma. The gallbladder, the cystic duct, the common bile duct and the pancreatic head were resected. The diagnosis was made on pathological examination; adjuvant chemotherapy followed. The patient was disease free 20 months following treatment.     

Evaluation of the Radiation-Protective Properties of Bi (Pb)–Sr–Ca–Cu–O Ceramic Prepared at Different Temperatures with Silver Inclusion

The influences of the sintering process and AgNO₃ addition on the phase formation and radiation shielding characteristics of Bi_1.6Pb_0.4Sr₂Ca₂Cu₃O₁₀ were studied. Three ceramics (code: C0, C1, and C2) were prepared as follows: C0 was obtained after calcination and only one sintering step, C1 was obtained after calcination and two sintering cycles, and C2 was prepared after the addition of AgNO₃ at the beginning of the final sintering stage. C2 displayed the maximum volume fraction of the Bi-2223 phase (76.4 vol%), the greatest crystallite size, and high density. The linear mass attenuation coefficient (µ) has been simulated using the Monte Carlo simulation. The µ values are high at 15 keV (257.2 cm⁻¹ for C0, 417.57 cm⁻¹ for C1, and 421.16 cm⁻¹ for C2), and these values dropped and became 72.58, 117.83 and 133.19 cm⁻¹ at 30 keV. The µ value for the ceramics after sintering is much higher than the ceramic before sintering. In addition, the µ value for C2 is higher than that of C1, suggesting that the AgNO₃ improves the radiation attenuation performance for the fabricated ceramics. It was demonstrated that the sintering and AgNO₃ addition have a considerable influence on the ceramic thickness required to attenuate the radiation.