Leila Shokrzadeh - Academia.edu (original) (raw)

Papers by Leila Shokrzadeh

Digestive and Liver Disease, Sep 1, 2009

Background-The cag pathogenicity island (PAI), which can divide into two parts: cagI and cagII, i... more Background-The cag pathogenicity island (PAI), which can divide into two parts: cagI and cagII, is the most well-known virulence factor of Helicobacter pylori. Aims-We investigated the association between genetic variations within the cag PAI (cagA and cagE in the cagI and cagT in the cagII) and clinical outcomes in Iranian population. Subjects-A total of 231 patients including 182 patients with gastritis, 41 with peptic ulcer and 8 with gastric cancer. Methods-The presences of the cagA, cagE and cagT genes were measured by polymerase chain reaction and the results were compared with clinical outcomes and gastric histology. Results-The cagA, cagE and cagT genes were found in 154 (66.7%), 90 (39.0%) and 70 (30.3%) of clinical isolates. At least 144 (62.3%) strains possessed partially deleted cag PAI (e.g., 69 [29.9%] strains were cagA-positive, but cagE and cagT-negative). Conclusion-The simple gene as well as the combination of the genes in the cag PAI appeared not to be useful markers to predict H. pylori-related diseases in Iranian population. The genomic sequences of the cag PAI in Iranian strains might be considerably different from those in other geographic locations.

Gastroenterology Insights, May 28, 2012

Although Helicobacter pylori (H. pylori) infection has been known to be associated with several u... more Although Helicobacter pylori (H. pylori) infection has been known to be associated with several upper gastrointestinal disorders such as peptic ulcer and gastric cancer, the relationship between H. pylori infection and dyspeptic symptoms remains controversial. Furthermore, it is still not clear which factors are associated with H. pylori infection in the Iranian population. We investigated the prevalence of H. pylori infection in dyspeptic patients and factors associated with H. pylori infection in the Iranian population. In this cross-sectional study, 303 patients with dyspeptic symptoms underwent endoscopy. Clinical data and a questionnaire about gastrointestinal symptoms were collected from each patient. H. pylori status was evaluated by histological examination. Among the 303 patients, 263 (86.8%) were found to be positive for H. pylori. The prevalence of H. pylori infection decreased significantly with age. There was no difference in the prevalence of H. pylori infection between the patients with and those without a family history of gastroduodenal diseases. Among 250 patients with abdominal pain, 219 (87.6%) were infected with H. pylori. Among 211 patients with epigastric abdominal pain, 185 (87.7%) were infected with H. pylori. It was observed that belching was significantly associated with H. pylori infection (P = 0.03). Dyspepsia triggered by the consumption of tea was higher in H. pylori-positive patients than in H. pylori-negative patients (P=0.03). The prevalence of H. pylori infection in dyspeptic patients was quite high in Iran. Belching and dyspepsia triggered by tea consumption was related with H. pylori infection. Statistical analysis SPSS version 18 (SPSS, Chicago, IL, USA) was used for statistical analyses. Multivariate and univariate logistic regression was performed to investigate the relationship between H. pylori status and variables. P<0.05 was considered statistically sig

Japanese Journal of Infectious Diseases, Jul 28, 2008

During a study examining causes of diarrhea from May 2004 to May 2005, 808 stool specimens were c... more During a study examining causes of diarrhea from May 2004 to May 2005, 808 stool specimens were collected from patients with acute diarrhea in Tehran. Fecal samples were cultured and identified according to the standard biochemical methods. Molecular identification of enteropathogens was carried out by amplification of their virulence genes by polymerase chain reaction. A total of 369 (45.6%) bacterial pathogens were recovered from 808 patients as follows: Shigella spp., 155 (45.6%); diarrheagenic Escherichia coli 143 (38.8%); Salmonella spp., 51 (13.8%); and Campylobacter spp., 20 (5.4%). Most of the diarrheagenic E. coli were Shiga toxin-producing E. coli, with 64 (44.7%) isolates, followed by 47 (32.9%) enterotoxigenic E. coli isolates; among Shigella spp. isolates, 69 (44.5%) Shigella flexneri were predominant. The molecular diagnosis of enteropathogens yielded a more accurate characterization of the prevalence of diarrhea-causing bacterial strains in Iran. The present study revealed a high prevalence of Shigella and diarrheagenic E. coli as the predominant causes of bacterial diarrhea in this region of the world. These two types of bacteria should therefore be considered when designing preventive strategies for people living in Iran.

The American Journal of Gastroenterology, Sep 1, 2007

s S441 Diseases, Shaheed Beheshti University of Medical Science, Tehran, Islamic

Iranian Journal of Microbiology

Background and Objectives: The present study was to evaluate the microbial diversity inhabiting b... more Background and Objectives: The present study was to evaluate the microbial diversity inhabiting biodeteriorated precious manuscripts of the Holy Quran placed in one of the repositories of the Library of Astan Quds Razavi (AQR), and its relation to the air microbial diversity. Materials and Methods: Three non-invasive sampling methods, culture-based techniques, and molecular identification were used to investigate the microorganisms involved in deterioration. To investigate the air microbial quality and its role in the destruction of the repository objects, air samples were taken from six different points inside the repository. Biomodeling studies were designed to verify the impact of microbial isolates. Results: 14 fungal isolates were obtained from three deteriorated ancient Quran manuscripts. The most frequently isolated fungi from the different substrates were Aspergillus spp. and Penicillium spp. In the air, the prevalence across fungal gen- era was rather uniform. 30 species of...

Saudi Journal of Gastroenterology, 2011

Background/Aim: Helicobacter pylori is an important pathogen for gastroduodenal diseases. Infecti... more Background/Aim: Helicobacter pylori is an important pathogen for gastroduodenal diseases. Infection with H. pylori can be limited by regimens of multiple antimicrobial agents. However, antibiotic resistance is a leading cause of treatment failure. The aim of this study has been to determine the resistance patterns of H. pylori strains isolated from gastric biopsies of patients with dyspepsia by agar dilution method, in Tehran, Iran. Patients and Methods: H. pylori isolates from patients with gastrointestinal diseases were evaluated for susceptibility testing by agar dilution method. Susceptibility testing was performed to commonly used antibiotics including clarithromycin, tetracycline, amoxicillin, metronidazole and ciprofloxacin. Results: Among 92 patients with dyspepsia, H. pylori strains were isolated from 42 patients. Seventeen (40.5%) of the isolates were resistant to metronidazole (MICs ≥ 8 μg/l), whereas one isolate (2.4%) was resistant to amoxicillin (MICs ≤ 0. 5 μg/ml) and ciprofloxacin (MICs ≤ 1μg/ml). The resistance rates to other antibiotics in H. pylori isolates are recorded as follows: clarithromycin 6 (14.3 %), tetracycline 2 (4.8%). In 5 of 42 resistant cases, combined resistance was found. Conclusions: These data suggest that metronidazole should be used among Iranian patients in first-line therapy with caution, and ciprofloxacin in association with amoxicillin and a proton pump inhibitor is more recommended.

Iranian Journal of Medical Microbiology, 2007

Iranian Journal of Clinical Infectious Disease 2008;3(2):73-77 ... Iranian Journal of Clinical In... more Iranian Journal of Clinical Infectious Disease 2008;3(2):73-77 ... Iranian Journal of Clinical Infectious Diseases 2008;3(2):73-77 ©2008 IDTMRC, Infectious Diseases and Tropical Medicine Research Center ... Increase in prevalence of vancomycin resistant isolates of

International Journal of Antimicrobial Agents, 2007

Introduction: Cystic Fibrosis (CF) is a genetically inherited disease affecting around 1 in 3,000... more Introduction: Cystic Fibrosis (CF) is a genetically inherited disease affecting around 1 in 3,000 children and young adults in the UK. It is characterised by a progressive decline in pulmonary function, exacerbated by the acquisition of specific microorganisms , in particular Pseudomonas aeruginosa. To date, no cure is available and the life span of sufferers is directly influenced by the effectiveness of local infection control practices. However, at the present time, detection of cross-infection episodes is entirely dependent on the genotyping service provided off-site. Methods: Isolates of Ps. aeruginosa grown from CF patients were collected throughout 2005. An in-house molecular typing method using the Random Amplification of Polymorphic DNA (RAPD) technique was developed and genetic profiles of the isolates were analysed compared using BioNumerics v.4.0 computer software. Results: DNA extracts from 90 Ps. aeruginosa strains grown from 19 CF patients have been analysed using RAPD. Strains determined to be unique to a single patients by the Reference Laboratory clustered together, demonstrating >80% homology using RAPD. Transmissible strains known to be genotypically related, which were cultured from different patients, demonstrated a similar degree of homology. The advantage for infection control purposes is the rapid availability of results with on-site molecular screening. Conclusions: Initial data indicate that RAPD allows recognition of unique Ps. aeruginosa strains and allows discrimination between diverse strains, to a level which is adequate for routine screening purposes.

BMC Medical Genetics, 2013

Background: The incidence of Alzheimer's disease, particularly in developing countries, is expect... more Background: The incidence of Alzheimer's disease, particularly in developing countries, is expected to increase exponentially as the population ages. Continuing research in this area is essential in order to better understand this disease and develop strategies for treatment and prevention. Genome-wide association studies have identified several loci as genetic risk factors of AD aside from apolipoprotein E such as bridging integrator (BIN1), clusterin (CLU), ATP-binding cassette sub-family A member 7 (ABCA7), complement receptor 1 (CR1) and phosphatidylinositol binding clathrin assembly protein (PICALM). However genetic research in developing countries is often limited by lack of funding and expertise. This study therefore developed and validated a simple, cost effective polymerase chain reaction based technique to determine these single nucleotide polymorphisms. Methods: An allele-specific PCR method was developed to detect single nucleotide polymorphisms of BIN1 rs744373, CLU rs11136000, ABCA7 rs3764650, CR1 rs3818361 and PICALM rs3851179 in human DNA samples. Allelespecific primers were designed by using appropriate software to permit the PCR amplification only if the nucleotide at the 3'-end of the primer complemented the base at the wild-type or variant-type DNA sample. The primers were then searched for uniqueness using the Basic Local Alignment Search Tool search engine. Results: The assay was tested on a hundred samples and accurately detected the homozygous wild-type, homozygous variant-type and heterozygous of each SNP. Validation was by direct DNA sequencing. Conclusion: This method will enable researchers to carry out genetic polymorphism studies for genetic risk factors associated with late-onset Alzheimer's disease (BIN1, CLU, ABCA7, CR1 and PICALM) without the use of expensive instrumentation and reagents.

AFP was observed in cytoplasm of Bel 7402 cells; The results is also showed that FRET was generat... more AFP was observed in cytoplasm of Bel 7402 cells; The results is also showed that FRET was generated between FITC and TRITC which labeled PTEN and AFP respectively, and appeared the distance of fluorescent molecules was 6.7±1.5 Å; Treated with ATRA could enhance the expression of PTEN and decrease the phosphorylation of AKT after knockdown the expression of AFP. Conclusions: These data provide the first evidence that AFP has a property to interact with PTEN and inhibit the activity of PTEN, this is also the pivotal events that AFP activated the transduction of PI3K/AKT signal of hepatoma cells.

Polish Journal of Microbiology, 2010

The geographical variation in Helicobacter pylori genotypes is an observed phenomenon. Cytotoxin ... more The geographical variation in Helicobacter pylori genotypes is an observed phenomenon. Cytotoxin associated genes A (cagA) and E (cagE), and vacuolating cytotoxin (vacA) genotypes of H. pylori are associated with peptic ulcer disease (PUD). This study compared the distribution of these genotypes in Iranian and Afghani isolates and their association with clinical outcomes. H. pylori infected patients, as proven by positive culture, were recruited prospectively. A total of 70 patients, 55 Iranian (26 men and 29 women, mean age 48 +/- 18 years) and 15 Afghani immigrants (13 men and 2 women, mean age 34.8 +/- 11 years) living in Tehran, Iran were enrolled in this study. DNA was extracted from isolated H. pylori and polymerase chain reaction was carried out to determine the cagA and cagE status and vacA alleles. The number of gastric cancer, peptic ulcer and gastritis cases was 11, 23 and 36, respectively. The cagA positive isolates were more common in Iranian (67%) than Afghani isolates...

Japanese journal of infectious diseases, 2008

Mosaicism in vacA alleles with two distinct families of vacA signal sequences (s1 and s2) and two... more Mosaicism in vacA alleles with two distinct families of vacA signal sequences (s1 and s2) and two distinct families of middle region alleles (m1 and m2) has been reported. Research suggests that the vacA s1 genotype is closely associated with duodenal ulcer disease and with high cytotoxin production. The aims of this study were to evaluate the role of vacA genotyping with respect to gastric inflammation and injury, and clinical presentation in Iranian populations. Genomic DNA of biopsy specimens from patients with gastritis, peptic ulcer disease (PUD), or gastric cancer (GC) were characterized based on ureC (glmM), cagA, and vacA genotyping by using polymerase chain reaction. Of 167 patients including 33 with PUDs, 129 with non-ulcer dyspepsia (NUD), and 5 with GC, 96 (57.5%) cases were infected by Helicobacter pylori. Among these patients, H. pylori were isolated from 19 (57.7%) PUD patients, 74 (68.7%) NUD patients, and 3 (60%) GC patients. The cagA was detected in 76% of H. pylor...

Microbial Drug Resistance, 2006

Disks containing 120 g of gentamicin were used to detect high-level gentamicin-resistant phenotyp... more Disks containing 120 g of gentamicin were used to detect high-level gentamicin-resistant phenotype (HLGR) among isolates of Enterococcus faecalis (n ‫؍‬ 79) and E. faecium (n ‫؍‬ 35). These isolates were collected from three hospitals in Tehran during 2002-2004. The macrobroth dilution assay was then used to determine the minimum inhibitory concentration (MIC) of gentamicin. The susceptibility of isolates against amikacin, netilmicin, tobramycin, and kanamycin were also determined by Kirby-Bauer method. All isolates were subjected to polymerase chain reaction (PCR) assays targeting aminoglycoside modifying enzyme (AMEs) genes including aac(6)-aph(2؆), aph(2؆)-Ib, aph(2؆)-Ic, aph(2؆)-Ia, aph(2؆)-Id, aph(3)-IIIa, and ant(4)-Ia. Fifty-nine isolates (52%) showed HLGR phenotype. All isolates with HLGR phenotype and those showing 64 Ͻ MIC Ͻ 500 g/ml contained aac(6)-aph(2؆). The aph(3)-IIIa was found in 61% of the isolates with HLGR phenotypes and in 65% of isolates with MIC Ͻ 500. Coexistence of aac(6)-aph(2؆) and aph(3)-IIIa gene among HLGR isolates of E. faecalis and E. faecium were 60% and 65%, respectively. The gene aph(2؆)-Ic was amplified in two isolates of E. faecium. The results of PCR for aph(2؆)-Id, ant(4)-Ia and aph(2؆)-Ib genes were negative. The aac(6)-aph(2؆) was the most frequent gene encoding resistance to gentamicin and other aminoglycosides followed by aph(3)-IIIa. Isolates lacking these genes were susceptible to all aminoglyocosides tested in this study.

Journal of Gastroenterology and Hepatology, 2010

The 3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp... more The 3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; region of the cagA gene, the most well-known virulence factor of Helicobacter pylori, contains Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs. Four segments flanking the EPIYA motifs, EPIYA-A, -B, -C, or -D, were reported to play important roles in H. pylori-related gastroduodenal pathogenesis. The aim was to determine the roles of EPIYA segments in gastroduodenal pathogenesis in an Iranian population. A total of 92 cagA-positive Iranian strains isolated from dyspepsia patients with non-ulcer dyspepsia (n = 77), peptic ulcer (n = 11) and gastric cancer (n = 4) were studied. The EPIYA motif genotyping was determined by polymerase chain reaction and sequencing. A total of 86 (93.5%) strains had three copies of EPIYA (ABC type), three (3.3%) had four copies (ABCC type) and three (3.3%) had two copies (AB type). The alignment of the deduced protein sequences confirmed that there were no East Asian type EPIYA-D sequences (EPIYATIDFDEANQAG) in Iranian strains. When the prevalence of strains with multiple EPIYA-C segments in Iran was compared with previously published data, it was much lower than that in Colombia and Italy, but was higher than that of Iraq, and the patterns were parallel to the incidence of gastric cancer in these countries. The structure of the 3&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; region of the cagA gene in Iranian strains was Western type. Although we could not find differences between EPIYA types and clinical outcomes, low prevalence of strains with multiple EPIYA-C segments might be reasons for low incidence of gastric cancer in Iran.

Canadian Journal of Microbiology, 2008

Infections with high levels of gentamicin-resistant (HLGR) isolates of Enterococcus faecalis are ... more Infections with high levels of gentamicin-resistant (HLGR) isolates of Enterococcus faecalis are common in Tehran hospitals. Genes encoding such resistance are transmissible by conjugation at high frequency. The purpose of this study was to determine the existence of Tn5281 and its flanking aminoglycoside modifying enzyme gene aac(6′)-aph(2″) among 102 HLGR isolates of E. faecalis cultured from patients at three hospitals in Tehran, Iran. These isolates were detected by disks containing 120 μg of gentamicin and made 65% of all E. faecalis during the study period. DNA was extracted from HLGR isolates and subjected to PCR assays targeting aac(6′)-aph(2″) and conjugative transposon Tn5281. The amplified aac(6′)-aph(2″) gene was labeled with digoxigenin and probed with Tn5281 amplicons in dot blot hybridization assays. The aac(6′)-aph(2″) gene was detected in 91%–92% (n = 93) of the HLGR isolates. All isolates containing aac(6′)-aph(2″) were positive in long-PCR targeting Tn5281 and the...

Background and Objective: Helicobacter pylori has several strains with different degrees of virul... more Background and Objective: Helicobacter pylori has several strains with different degrees of virulence. The aim of this study was to detect two major important virulence factors, cagA/vacA genotypes, and to determine correlations among different cagA/vacA genotypes and histological features of chronic gastritis in Iranian patients. Methods: In this cross-sectional study, gastric biopsy was taken from 166 patients with non-ulcer dyspepsia. The specimens were processed for DNA extraction and identification of glmM gene. The vacA subtypes and cagA gene were tested by PCR. Histopathological features were recorded and graded according to updated Sydney system. Results: 76.7% of the H.pylori strains were cagA gene positive. The proportions of vacA gene subtypes s1, s2, m1 and m2 in the 78 strains isolated were 70.5%, 29.5%, 37.2% and 62.8%, respectively. 83.3% of the vacA-positive strains had s1 allele. Twenty-six strains (33.3%) were positive for both cagA and m1 allele. Positive cagA status and vacA subtypes were not associated significantly with presence of neutrophil infiltration, intestinal metaplasia or H.pylori density. Only vacA s1 was significantly associated with more severe inflammation (P=0.02). The dominant genotype of H.pylori was vacA-positive s1/m2. CagA gene positivity rate was not closely associated with severity of the disease. Conclusion: H.pylori strains showing vacA s1 genotype were associated with more severe gastritis. These findings show that vacA genotyping may have clinical relevance in Iran.

Fungi are the most important agents of biodeterioration in museums, libraries, and repositories. ... more Fungi are the most important agents of biodeterioration in museums, libraries, and repositories. The objective of the present study was to evaluate the microbial diversity in biodeteriorated manuscripts located in a repository of the central library of Astan Quds Razavi and to estimate the fungal occurrence of the repository air. The sterile cotton swabs and nitrocellulose membranes were used for sampling the manuscripts, while the sedimentation method was used for the microbial sampling of air. To evaluate the biodeteriorative impacts of fungi, fungal spore's suspension inoculated on paper strips. 14 and 6 fungal isolates were collected from the three different deteriorated substrates and the repository air samples, respectively. Among the fungi isolates, Aspergillus sp. was isolated in high frequency (36%), followed by Penicillium sp. (21.5%) and Alternaria sp. (14%). Fungi species including P. chrysogenum, Cladosporium cladosporioides, Talaromyces diversus, and Aspergillus sp...