Evaluation of a novel real-time PCR test based on the ssrA gene for the identification of group B streptococci in vaginal swabs

<p>Abstract</p> <p>Background</p> <p>Despite the implementation of prevention guidelines, early-onset group B streptococci (GBS) disease remains a cause of neonatal morbidity and mortality worldwide. Strategies to identify women who are at risk of transmitting GBS to their infant and the administration of intrapartum antibiotics have greatly reduced the incidence of neonatal GBS disease. However, there is a requirement for a rapid diagnostic test for GBS that can be carried out in a labour ward setting especially for women whose GBS colonisation status is unknown at the time of delivery. We report the design and evaluation of a real-time PCR test (<it>RiboSEQ </it>GBS test) for the identification of GBS in vaginal swabs from pregnant women.</p> <p>Methods</p> <p>The qualitative real-time PCR <it>RiboSEQ </it>GBS test was designed based on the bacterial <it>ssrA </it>gene and incorporates a competitive internal standard control. The analytical sensitivity of the test was established using crude lysate extracted from serial dilutions of overnight GBS culture using the IDI Lysis kit. Specificity studies were performed using DNA prepared from a panel of GBS strains, related streptococci and other species found in the genital tract environment. The <it>RiboSEQ </it>GBS test was evaluated on 159 vaginal swabs from pregnant women and compared with the GeneOhm™ StrepB Assay and culture for the identification of GBS.</p> <p>Results</p> <p>The <it>RiboSEQ </it>GBS test is specific and has an analytical sensitivity of 1-10 cell equivalents. The <it>RiboSEQ </it>GBS test was 96.4% sensitive and 95.8% specific compared to "gold standard" culture for the identification of GBS in vaginal swabs from pregnant women. In this study, the <it>RiboSEQ </it>GBS test performed slightly better than the commercial BD GeneOhm™ StrepB Assay which gave a sensitivity of 94.6% and a specificity of 89.6% compared to culture.</p> <p>Conclusion</p> <p>The <it>RiboSEQ </it>GBS test is a valuable method for the rapid, sensitive and specific detection of GBS in pregnant women. This study also validates the <it>ssrA </it>gene as a suitable and versatile target for nucleic acid-based diagnostic tests for bacterial pathogens.</p

Membrane effects of sex hormones on growth plate chondrocytes

Understanding and studying the normal bone growth and development is causal. Bone and cartilage tissue provide in addition to their mechanical support, they provide a protection for vital organs such as heart, lung and brain. Longitudinal growth is regulated by the activity of chondrocytes in the epiphyseal growth plates of long bones. Many hormones and growth factors are involved in the regulation of this process. Among these, sex steroids are of crucial importance, especially during puberty. In long bones, endochondral bone formation occurs at the growth plate, a region of developing cartilage located between the epiphysis and the metaphysic. The process of endochondral ossification is regulated in part by sex steroid hormones. Androgens stimulate endochondral bone growth and elongation, while estrogen is known to suppress longitudinal bone growth and accelerate growth plate closure. Studies using rat costochondral growth plate chondrocytes as a model show that the effects of 17β-estradiol (E₂) on apoptosis are found in both male and female cells and the same mechanism is involved. In contrast, E₂ causes rapid activation of PKC in female cells but not in male cells. Dihydroxytestosterone (DHT) also has direct effects on growth plate chondrocytes, increasing matrix synthesis including sulfated glycosaminoglycan production, and enhancing cell maturation by increasing alkaline phosphatase enzymatic activity. Short stature and abnormally slow increase in height is one of the main reasons for referral to endocrinologist. Excessive growth and abnormally tall is also a problem, especially because it increase risk for the trunk abnormalities. Furthermore until now a few growth-promoting therapies are available for clinical use. Therefore future therapies for treating the growth disorders are essential. The overall goal of this project is to investigate the sexual-dimorphic effect of the sex steroid hormone in rat growth plate chondrocytes, the cellular signaling pathways mediating these actions, and their physiological role. The information gleaned from this study will provide new information about the role of sex steroid hormones in chondrogenesis and has implications in the development of new therapies for the treatment of bone fracture healing, and growth plate disorders. The central hypothesis was that sex steroid would play an important and sex-specific role in regulating chondrocytes as a main regulator of longitudinal bone growth.PhDCommittee Chair: Barbarab, Boyan; Committee Co-Chair: Schwartz, Zvi; Committee Member: Chernoff, Yury; Committee Member: Lobachev,Kirill; Committee Member: Wartell, Roge

Maternal and Neonatal Screening for Group B Streptococci by SCP B Gene Based PCR: A Preliminary Study

Objective: To detect the magnitude of group B streptococcal (GBS) colonization and disease among a sample of pregnant women and their infants in Egypt. Study Design: Prospective observational study. Participants: The study included 95 pregnant females, 35-37 weeks of gestational age, attending the antenatal outpatient clinic at AlFayom University Hospital between September 2006 and June 2007. All participants were screened with vaginorectal swabs by a conventional GBS PCR assay. Participants were grouped into group A (GBS present, 17 patients) and group B (GBS absent, 78 patients). Details with regard to labor and delivery were recorded and placental pathology was examined to detect histological chorioamnionitis. Ninety-five infant data were also recorded. All neonates of group A (17 out of 95 with known positive maternal GBS) underwent collection of simultaneous specimens from surface sites for PCR before their first bath and within four hours of birth. Results: GBS carriage rate in the study sample was 17.89%. Chorioamnionitis confirmed in three patients by placental pathology (one was in group A and two in group B) was statistically not significant. Twenty-two women had rupture of membranes (< 12 hours) before delivery (four from group A and 18 from group B) that was not statistically significant. There were three infants out of 17 in group A who had GBS colonized at one or more sites by PCR which was statistically significant. However, only one infant was admitted to neonatal intensive care unit (NICU) that was not statistically significant. Conclusion: Maternal GBS carriage is associated with a significant increase in neonatal infection rate but is not associated with an increase in neonatal intensive care admission. An accurate evaluation of colonization rate (using a larger sample) is desired to evaluate neonatal invasive disease and determine the cost effectiveness of PCR to select an appropriate preventive strategy in Egypt

Comparison of local and intra venous dexamethasone on post operative pain and recovery after caeseream section. A randomized controlled trial

Objective: To compare the effect of local infiltration and intravenous dexamethasone on postoperative pain and recovery after Cesarean Section (CS). Material and methods: A Prospective, randomized study conducted on 120 pregnant women attending the labor wards. All participants were scheduled for elective CS under spinal anaesthesia and were randomly divided into 3 equal groups. Group 1 received 16 mg Dexamethasone IV drip. Group II received 16 mg Dexamethasone subcutaneous injection around the caesarean section scar after skin closure and Group III received Placebo (500 cc saline infusion). All cases were followed up for 48 h for assessment of level of pain by using a 10-cm visual analog scale (VAS). Primary outcome parameters were VAS score and the need for additional analgesics. Other parameters were hemodynamic changes and occurrence of side effects or complications. Results: there was a highly statistically significant difference between placebo and local infiltration groups and between the placebo and IV groups regarding the needs for postoperative morphine. Comparing both interventional groups revealed statistically significant difference between local infiltration and IV groups regarding the needs for postoperative morphine. Conclusion: Local infiltration of dexamethasone is more effective than systemic administration to decrease postoperative pain with weaker antiemetic effect. NCT02784340