19 research outputs found
Collagenase Activity In Prevotella Bivius Isolated From Patients With Premature Rupture Of Membranes
Bacterial vaginosis (BV) has been considered to be the most prevalent
infection found in sexually active women. BV is thought to play an
important role in the premature rupture of membranes (PROM) and preterm
birth. Preterm delivery accounts for a substantial percentage of low
birth weight infants and perinatal mortality and morbidity. Bacteroides
and Prevotella species have been isolated from the amniochorion of
women with preterm birth and PROM. Women with >104 /mL Prevotella
bivius (formerly Bacteroides bivius ) have a 60-100% higher rate of
preterm delivery. The purpose of this study was to determine wether
some strains of Prevotella species isolated from PROM and BV patients
produce proteases especially collagenase enzymes which faciliate the
rupture of membranes leading to preterm birth. Vaginal specimens have
been obtained from 120 women with BV and premature rupture of membrane
in 30-44 weeks gestational age. Twenty anaerobic coccobacilli
consisting of Bacteroides fragilis , black pigmented Bacteroides and
Prevotella bivius were isolated and identified. The isolates were
examined for protease activity, using porcine skine gelatin and casein
as substrates by Martleys method. Elastase and collagenase activity
were detected using elastin, guinea pig skin collagen, bovine achilles
tendon collagen, FALGPA and GP,VPK as substrates by Levenson method.
Collagenase and elastase activity was detected in 90 and 100% of
isolates. Gelatinase and caseinase activity was detected in 40 and 50 %
of isolates. Collagenase produced by Prevotella bivia isolates was
purified by ammonium sulphate precipitation, gel filtration and ion
exchange chromatography. The collagenase was cleaved from the synthetic
collagen substrate FALGPA, and GP, VPK substrates. The activity of the
enzyme was inhibited by EDTA, Antipain and PMSF. This study suggests
that proteases produced by Prevotella bivia may be involved in the
pathogenesis of premature rupture of membrane. PROM before 37 weeks has
been reported to be significantly higher among patients with
Bacteroides and Prevotella colonisation of the genital tract. The
amniochorion consists of collagen and elastin which convey physical
integrity to the placenta. Collagenase and elastase released into the
genital tract may promote connective tissue destruction in the cervix
and chorioamnion membranes
High Prevalence of Helicobacter pylori hopQ II Genotype Isolated from Iranian Patients with Gastroduodenal Disorders
Helicobacter pylori plays an important role in the pathogenesis of chronic gastritis, peptic ulceration, and noncardia gastric cancer. Several putative virulence factors for H. pylori have been identified including vacA, babA, and iceA. HopQ is one of the outer membrane proteins involved in bacterial adherence to gastric mucosa and has been suggested to also play a role in the virulence of H. pylori. Due to the substantial geographic differences in the prevalence of H. pylori virulence factors reported, the main purpose of the current study was to investigate the association between different H. pylori virulence hopQ alleles (types I and II) and patients with gastroduodenal disorders. The presence of H. pylori and hopQ alleles in gastric biopsy specimens was identified by specific PCR assays. H. pylori type II hopQ was found to be significantly associated with gastric cancer patients (odds ratio: 3.47, 95% CI: 1.56–5.89). Information about the prevalence of H. pylori hopQ type II can be used for determining the high-risk diseases type which is actually colonized by H. pylori hopQ type II positive strains. The presence of H. pylori hopQ type II should be investigated in different geographical regions as confirmatory findings may provide a definite biomarker attributed to the pathogenesis of certain severe digestive diseases
First case of Helicobacter pyloriinfection resistant to seven antibiotics in Iran
Treatment of Helicobacter pylori infection with common antibiotics is typically recommended for several digestive conditions, including peptic ulcers. However, reports of resistant H. pylori isolates are increasing, and unfortunately, these do not respond to currently available therapeutic regimens. We report the case of a 31-year-old woman with two peptic ulcers in the duodenal antrum. An H. pylori strain was isolated, and tested for antibiotic resistance using agar dilution and disk diffusion. The isolated strain was found to be resistant to all seven antibiotics that were tested. Therefore, constant monitoring for antibiotic resistance should be performed prior to initiating antibiotic therapy
Detection of Viable But Non-Culturable State of Escherichia coli O157:H7 Using Reverse Transcription PCR
Background and Aims: Many bacteria including Escherichia coli may enter into a viable but non-culturable (VBNC) state under unfavorable stresses, which are unable to be detected by culture-based methods. In this study, the use of Reverse Transcription PCR (RT-PCR) for detection of VBNC state of E. coli O157:H7 was investigated.
Materials and Methods: Escherichia. coli O157:H7 was inoculated in distilled water and 30 percent salt water at room temperature. The cultivability of bacteria was determined using routine culture and colony counting on MacConkey agar. The RT-PCR of 16S rRNA gene involved direct extraction and purification of RNA, DNase I treatment for removing DNA contamination, cDNA synthesis and electrophoresis of PCR products of cDNA was used to detect viable E. coli O157:H7 under studied treatments and was compared with the results of RT-PCR of 16S rRNA gene of heat- killed bacteria.
Results: The cultivability of bacteria was maintained during the study period in distilled water; however, the use of 30percent NaCl caused the bacteria to be non-cultivable on day 4. The RT-PCR of 16S rRNA showed the positive expression of this gene in cultivable and non-cultivable bacteria during the study period, whereas heat-killed bacteria were negative for this gene, which indicated the efficacy of RT-PCR of 16S rRNA in differentiation of alive from dead bacteria.
Conclusions: Escherichia coli O157:H7 entered into the VBNC under 30 percent NaCl which can be associated with serious human health problems. RT-PCR can be used to detect bacteria in the VBNC state
Helicobacter pylori hrgA, A Novel Discriminatory Biomarker for Duodenal Ulcer Patients
Background: Helicobacter pylori is a major human gastric for various gastro duodenal diseases.A number of putative virulence factors such as dupA, homB, tnpA have been described. To date,none were found to be significantly associated with specific H. pylori-related diseases (e.g. gastric cancer and duodenal ulcer).
Methods: the primary aim of this study was to test the H. pylori hrgA genotype isolated from 253 Iranian symptomatic patients to investigate possible association with clinical outcomes. The positive culture results were confirmed by glmM (genetic control for H. pylori) PCR assay.
Results: The results showed hrgA gene was detected in 44/253 strains (17.3%). Prevalence of the hrgA gene was relatively high in strains isolated from duodenal ulcer patients (P=0.0063; Odd ratio: 3.54; CI 95%: 1.42-8.77).
Conclusions: In contrast our findings showed that the prevalence of hrgA in our control group (gastritis patients) was 22.7% (P>0.05). Conclusively, hrgA gene is a good candidate as a discriminatory biomarker for patients with duodenal ulce
[Milli Reasürans Sanat Galerisi tarafından düzenlenen Avni Arbaş resim sergisine ait davetiye]
Taha Toros Arşivi, Dosya No: 46-Avni Arbaş. Not: Sergi, 5 Mayıs - 6 Haziran 1998 tarihleri arasında düzenlenmiştir.Unutma İstanbul projesi İstanbul Kalkınma Ajansı'nın 2016 yılı "Yenilikçi ve Yaratıcı İstanbul Mali Destek Programı" kapsamında desteklenmiştir. Proje No: TR10/16/YNY/010