Effect of gold nanoparticles on the expression of efflux pump mexA and mexB genes of Pseudomonas aeruginosa strains by Quantitative real-time PCR

Antibiotic-resistant Pseudomonas aeruginosa infections are usually difficult to treat, and there are limited antibiotics for treating them. Increased antibiotic resistance of this bacterium, especially in a multidrug form, has caused many problems for treatment. Nowadays, metal nanoparticles are considered as appropriate alternatives to antibiotics. The objective of the present study was to investigate the effect of gold nanoparticles on the expression of MexB and MexA genes in Pseudomonas aeruginosa isolates.Pseudomonas aeruginosa isolate was identified using biochemical tests and an API kit. The antibiotic sensitivitytest for different antibiotics was performed withthe Kirby-Bauer test according to the CLSI standard. The presence of MexB and MexA genes was assessed by PCR. The effect of gold nanoparticles was investigated by microdilution to evaluate the minimum inhibitory concentration, and the expression of MexB and MexA treated genes was done with silver nanoparticles by the Real-Time PCR method.40 Pseudomonas aeruginosa isolates were detected and identified. These isolates showed significant resistance to various antibiotics. All strains were carriers of MexB and MexA genes, and finally, in the expression of MexB and MexA genes,a significant decrease in the expression of these genes was observed in the samples treated with gold nanoparticles compared to non-treated samples.One of the mechanisms of antibacterial activity of gold nanoparticles is through reducing the expression of mexA and mexB genes and thus reducing the number of active efflux pumps at the cell surface

Distribution and Characteristics of Bacteria Isolated from Cystic Fibrosis Patients with Pulmonary Exacerbation

Background. Cystic fibrosis (CF) is an inherited recessive disorder characterized by recurrent and persistent pulmonary infections, resulting in lung function deterioration and early mortality. Methods. A cross-sectional study was conducted on the bacterial profile and antibiotic resistance pattern of 103 respiratory specimens from CF patients with signs of pulmonary exacerbation. Antibiotic susceptibility testing and biofilm formation of Staphylococcus aureus and Pseudomonas aeruginosa isolates were performed by the Kirby–Bauer disc diffusion method and microtiter plate assay, respectively. Molecular typing of S. aureus and P. aeruginosa isolates was carried out by spa typing and repetitive extragenic palindromic element PCR. Results. In a total of 129 isolates, the most prevalent organisms were S. aureus (55.3%) and P. aeruginosa (41.7%). Other less prevalent bacterial isolates include coagulase-negative staphylococci, Escherichia coli, klebsiella spp., Enterobacter spp., and Achromobacter xylosoxidans. The highest rate of resistance for S. aureus was observed to azithromycin and erythromycin (80%), ciprofloxacin (52.3%), clindamycin (44.6%) and tetracycline (43%). Twenty percent of S. aureus isolates were methicillin-resistant S. aureus (MRSA) and 47.6% were MDR S. aureus. For P. aeruginosa isolates the highest resistance was to cefepime (38.3%) and levofloxacin (33.3%) and 20% showed MDR phenotype. Conclusion. Our study demonstrated a significant decline in the prevalence of P. aeruginosa infections in comparison to previous studies. We found S. aureus to be more prevalent in younger patients, whereas mucoid P. aeruginosa showed a shift in prevalence toward older ages. Molecular typing methods showed great diversity between isolates

miRNA-21 expression analysis in 35 colorectal cancer

Background: Colorectal cancer is the third most common cancer in the world. Non-coding RNA especially miRNAs have important regulatory roles in cancer. miRNAs are small non coding RNA 21-23 nucleotides long which have different levels of expression between tumors and normal tissues. This study was designed to compare expression level of miRNA-21 between Iranian population colorectal cancer tissues and normal tissue. Methods: This case-control study has performed in medical genetics department of Tehran University of Medical Sciences from January to November 2013. We used 35 samples. The samples were isolated from tumor and adjacent normal tissues of colon. Thirty-five samples were divided into different groups according to cliniopathologic features including tumor size (>4 and 4 and <4 cm) and metastatic (+ and -), miRNA-21 over expressed in both groups, however the increase was not statistically significant. Conclusion: In this study, we found miR-21 over-expression in advanced stage in tu-moral tissue comparing with normal adjacent tissue. This means perhaps in the future it would be possible to use miRNA-21 as an informative prognostic biomarker to guide for better treatment strategies for colorectal cancer patients. Our findings also indicate that miRNA-21 is a promising new molecular target for designing novel therapeutic strategies to control colorectal cancer

The effect of ovalbumin on orthodontic induced root resorption

Background: This randomized trial was undertaken to investigate the effect of experimentally induced allergy on orthodontic induced root resorption. Materials and Methods: A total of 30 Wistar rats were divided randomly into test and control groups. Starting from the first 3 days, the rats in the test group were injected intra-peritoneally by 2 mg ovalbumin as allergen and 0.5 mg Alume as adjuvant. Afterward only allergen was injected once a week. The control group was injected by normal saline. After 21 days, Wistar immunoglobulin E was measured and peripheral matured eosinophil was counted. A total of 50 g nickel-titanium closed coil spring was ligated between right incisor and first molar. All animals were sacrificed after 14 days. The mesial root of the right and left first molar was dissected in a horizontal plane. The specimens were divided into four groups considering whether force and/or ovalbumin was applied or not. Root resorption was measured and compared among these groups. Repeated measures analysis of variance (ANOVA), and Bonferoni tests were used to analyze the data. The level of significance was determined at 0.05. Results: In general, the differences were insignificant (P > 0.05). As the only exception, the group in which both ovalbumin and force were applied had significantly more root resorption than the group in which neither force nor ovalbumin was applied (P < 0.001). Conclusion: Allergy may increase the susceptibility to root resorption. Application of light force, periodical monitoring of root resorption and control of allergy are advisable

Elevation-dependent intensification of fire danger in the western United States

Studies have identified elevation-dependent warming trends, but investigations of such trends in fire danger are absent in the literature. Here, we demonstrate that while there have been widespread increases in fire danger across the mountainous western US from 1979 to 2020, trends were most acute at high-elevation regions above 3000 m. The greatest increase in the number of days conducive to large fires occurred at 2500-3000 m, adding 63 critical fire danger days between 1979 and 2020. This includes 22 critical fire danger days occurring outside the warm season (May-September). Furthermore, our findings indicate increased elevational synchronization of fire danger in western US mountains, which can facilitate increased geographic opportunities for ignitions and fire spread that further complicate fire management operations. We hypothesize that several physical mechanisms underpinned the observed trends, including elevationally disparate impacts of earlier snowmelt, intensified land-atmosphere feedbacks, irrigation, and aerosols, in addition to widespread warming/drying

Elevation-dependent intensification of fire danger in the western United States

Elevation-dependent warming trends have been previously identified, but its effect on fire danger is still unclear. Here the authors show that there has been widespread increases in fire danger across the mountainous western US from 1979 to 2020 with most acute trends at high-elevation regions above 3000 m

Academic Performance, Sleep Disorders and Their Association in Middle School Students in Iran

Background: Although sleep disorders are common problems among families and they affect the learning, memory processes and academic performance of children, there is no evaluation of these disorders in Iran. The aim of this study was to assess the prevalence of sleep disorders and its association with academic performance of school age children.Materials and Methods: A cross-sectional study was conducted on 1,100 middle school students of Isfahan city of Iran during 2012-2013. Multi-stage random cluster sampling method was performed and five girl’s schools and five boy’s schools were selected. The data gathered with a validated questionnaire to evaluate the academic performance and sleep disorders.Results: The mean duration of nocturnal sleep was 8.38±1.17 which was significantly higher in the group with excellent academic performance (8.86±1.18 hours), than the other two groups (8.14±1.17 hours for average academic performance and 7.90±1.15 hours for poor academic performance). Academic performance was significantly associated with age, gender, parental occupation, nocturnal sleep time, sleep latency and sleep disorders (

Comprehensive assessment of respiratory complications in patients with common variable immunodeficiency

[Background] Common variable immunodeficiency (CVID) is a heterogeneous group of disorders, characterized by recurrent upper and lower respiratory tract infections and some noninfectious clinical complications.[Objective] To provide a detailed evaluation of respiratory presentations and complications in a cohort of Iranian patients with CVID.[Methods] A retrospective cohort study was conducted on 245 CVID patients who were recorded in the Iranian primary immunodeficiency disorders registry network. Respiratory manifestations were evaluated by reviewing clinical hospital records, immunologic findings, pulmonary function tests (PFT), and high-resolution computed tomography (HRCT) scans.[Results] Most of the patients (n = 208, 85.2%) had experienced at least 1 episode of acute respiratory manifestation, and pneumonia was observed in 31.6 % (n = 77) of cases as a first disease manifestation. During the follow-up, pneumonia, sinusitis, and otitis media were documented in 166 (68.6%), 125 (51.2%), and 103 (42.6%) cases, respectively. Abnormal PFT measurements were documented in 53.8% of patients. Among these patients, 21.5% showed restrictive changes, whereas 18.4% of patients showed an obstructive pattern. Bronchiectasis was the most frequent radiological finding, confirmed in 27.2% of patients. Patients with bronchiectasis were older at the time of immunodeficiency diagnosis (P < .001) and had longer diagnosis delay (P < .001) when compared with patients without bronchiectasis.[Conclusion] This study highlights the importance of monitoring the respiratory tract system even in asymptomatic patients. Pulmonary function tests and CT scans are the most commonly used techniques aiming to identify these patients early, aiming to reduce the rate of long-term respiratory complications.Funding Sources: This research was supported by the Tehran University of Medical Sciences, Tehran, Iran (grant no. 35741)

LPS-Responsive Beige-Like Anchor Gene Mutation Associated With Possible Bronchiolitis Obliterans Organizing Pneumonia Associated With Hypogammaglobulinemia and Normal IgM Phenotype and Low Number of B Cells

LPS-Responsive Beige-like Anchor (LRBA) deficiency is a disease which has recently been described in a group of patients with common variable immunodeficiency (CVID) in association with autoimmunity and/or inflammatory bowel disease (IBD)-like phenotype. We here describe a 10-year-old boy who experienced recurrent infections, mainly in the respiratory system, associated with thrombocytopenia and anemia. Immunological workup showed low numbers of B cells and low IgG, but normal IgM levels. In spite of therapeutic doses of antibiotics, antivirals, and antifungal agents, in addition to immunoglobulin replacement therapy, he developed disseminated involvement of both lungs with peripheral nodules; transbronchial lung biopsy revealed possible bronchiolitis obliterans organizing pneumonia (BOOP). Combined homozygosity mapping and exome sequencing identified a homozygous LRBA mutation in this patient (p.Asp248Glufs*2). Such clinical and immunological findings have not been described to date and illustrate the broad and variable clinical phenotype of human LRBA deficiency