Crystal size and shape distribution systematics of plagioclase and the determination of crystal residence times in the micromonzogabbros of Qisir Dagh, SE of Sabalan volcano (NW Iran)

The Qisir Dagh igneous complex occurs as a combination of volcanic and intrusive rocks to the south-east of the Sabalan volcano, north-western Iran. Micromonzogabbroic rocks in the region consist of plagioclase, alkaline feldspar and clinopyroxene as the major mineral phases and orthopyroxene, olivine, apatite and opaque minerals as the accessory minerals. Microgranular and microporphyritic textures are well developed in these rocks. Considering the importance of plagioclase in reconstructing magma cooling processes, the size and shape distribution and chemical composition of this mineral were investigated. Based on microscopic studies, it is shown that the 2-dimensional size average of plagioclase in the micromonzogabbros is 538 micrometers and its 3-dimensional shape varies between tabular to prolate. Crystal size distribution diagrams point to the presence of at least two populations of plagioclase, indicating the occurrence of magma mixing and/or fractional crystallization during magma cooling. The chemical composition of plagioclase shows a wide variation in abundances of Anorthite-Albite-Orthoclase (An = 0.31—64.58, Ab = 29.26—72.13, Or = 0.9—66.97), suggesting a complex process during the crystal growth. This is also supported by the formation of antiperthite lamellae, which formed as the result of alkali feldspar exsolution in plagioclase. The calculated residence time of magma in Qisir Dagh, based on 3D crystal size distribution data, and using growth rate G = 10—10 mm/s, varies between 457 and 685 years, which indicates a shallow depth (near surface) magma crystallization and subvolcanic nature of the studied samples

Synergistic effect of silver nanoparticles with streptomycin on the streptomycin-resistant Brucella abortus

زمینه و هدف: بروسلا (Brucella) عامل یک‌ بیماری‌ عفونی با درمان سخت‌ است‌ که با گسترش مقاومت دارویی و عود مجدد عفونت، پس از درمان روبروست. همچنین اثرات جانبی مصرف آنتی‏بیوتیک‏هایی که برای درمان به کار می‌روند بسیار بالاست. این مطالعه با هدف طراحی مسیری برای از بین بردن مقاومت دارویی و استفاده از دوز پایین تر آنتی‌بیوتیک‌ها برای درمان بروسلوز طراحی شده است. روش بررسی: در این مطالعه تجربی، بعد از سنتز نانو ذرات نقره به روش احیاء نیترات نقره، کشت بروسلا آبورتوس بیماری زا در انسان بر روی مولر هینتون آگار انجام و دیسک گزاری به روش کربی‏بائر (Kirby-Bauer) همراه با غلظت‌های متفاوت نانو ذره نقره انجام شد. اثر هم‏افزایی با استرپتومایسین نیز با آغشته کردن دیسک آنتی‏بیوتیک استرپتومایسین (10 میکروگرم) با بیشترین غلظت نانو ذره که اثر مهارکنندگی نداشت، صورت گرفت. یافته‌ها: نتایج بررسی اثر نانو ذره نقره بر روی بروسلا آبورتوس مقاوم به استرپتومایسین نشان داد که رقت‌های بالای 25 میلی مول به تنهایی موجب مهار رشد بروسلا آبورتوس می‌شوند. ارزیابی اثر هم افزایی نانو ذرات نقره به همراه آنتی‌بیوتیک استرپتومایسین نشان داد که پلیت های حاوی دیسک آنتی‌بیوتیک استرپتومایسین به همراه نانو ذرات نقره با رقت 50/12 میکرو‏مول سبب ایجاد هاله عدم رشد مطابق با موسئسه ایتانداردهای آزمایشگاهی و بالینی (CLSI=Clinical of laboratory standard institue) می‏شود. نتیجه گیری: نتایج این مطالعه نشان داد که نانو ذرات نقره به تنهایی رشد باکتری را کنترل می‏کنند. به نظر می‏رسد نانو ذرات نقره در کنار آنتی‌بیوتیک، مقاومت دارویی باکتری را از بین می‏برند. استفاده از نانو ذرات در کنار آنتی‌بیوتیک‌های رایج، ما را قادر خواهد ساخت تا از غلظت بسیار کمتر آنتی‏بیوتیک‏ها و نانو ذرات استفاده کنیم و اثرات سوء آن‌ها را کاهش دهیم

Rapid DNA extraction of bacterial genome using laundry detergents and assessment of the efficiency of DNA in downstream process using polymerase chain reaction

Genomic DNA extraction from bacterial cells involves processes normally performed in most biological laboratories. Therefore, various methods have been offered, manually and kit, but these methods may be time consuming and costly. In this paper, genomic DNA extraction of Pseudomonas aeruginosa was investigated using some laundry detergent brands available in Iran. Afterwards, efficiency of the detergents was compared with manually standard methods and kits. To evaluate the efficiency of the genomic DNA in the processes in which DNA is used as a template, the polymerase chain reaction (PCR) tests and enzyme digestion of PCR product were used. The results show that the detergents could be used to extract genomic DNA. Among the brands studied, five-enzyme Taj and three-enzyme Saftlan had the best performance compared to standard methods.Key words: Bacterial genome, DNA extraction, laundry powder, detergent

Biofilm formation in clinical isolates of nosocomial Acinetobacter baumannii and its relationship with multidrug resistance

AbstractObjectiveTo check biofilm formation by Acinetobacter baumannii (A. baumannii) clinical isolates and show their susceptibility to different antibiotics and investigate a possible link between establishment of biofilm and multidrug resistance.MethodsThis study was performed on clinical samples collected from patients with nosocomial infections in three hospitals of Tehran. Samples were initially screened by culture and biochemical tests for the presence of different species of Acinetobacter. Identifications were further confirmed by PCR assays. Their susceptibilities to 11 antibiotics of different classes were determined by disc diffusion method according to Clinical and Laboratory Standards Institute guidelines. The ability to produce biofilm was investigated using methods: culture on Congo red agar, microtiter plate, and test tube method.ResultsFrom the overall clinical samples, 156 specimens were confirmed to contain A. baumannii. The bacteria were highly resistant to most antibiotics except polymyxin B. Of these isolates, 10.26% were able to produce biofilms as shown on Congo red agar. However, the percentage of bacteria with positive biofilm in test tube, standard microtiter plate, and modified microtiter plate assays were 48.72%, 66.66%, and 73.72%, respectively. At least 92% of the biofilm forming isolates were multidrug resistant.ConclusionsSince most of the multidrug resistant strains produce biofilm, it seems necessary to provide continuous monitoring and determination of antibiotic susceptibility of clinical A. baumannii. This would help to select the most appropriate antibiotic for treatment

Prevalence of Mycoplasma genitalium and Mycoplasma hominis isolates among Women with Cervicitis Referred to Karaj Health Care Centers

Background and Objectives: Mycoplasma is a genus of bacteria often found in the normal flora of the mouth, respiratory system and urogenital tract; but potentially pathogenic species also exist which can cause serious respiratory and genital diseases in human including postpartum fever, pelvic inflammatory infections, and pyelonephritis. The aim of this study was to evaluate the prevalence of Mycoplasma genitalium and Mycoplasma hominis in women who referred to the health centers in Karaj and investigate the susceptibility of M. genitalium strains against Fluoroquinolone antibiotics.Materials & Methods: Endocervical swabs were taken from 200 women with cervicitis. Nucleic Acid Amplification Tests (NAATs) were performed for detecting Mgpa gene in M. genitalium and RNH gene in M. hominis. Mutations in parC and gyrA genes, as well as antibiotic resistance, were studied in positive samples of M. genitalium.Results: 9 M. genitalium and 11 M. hominis positive samples were found among samples obtained from women with cervicitis. Positive samples of M.genitalium were examined for isolating the parC and gyrA genes. Six sequences of these genes were analyzed by MEGA5 software. Mutation in parC gene was observed in one sequence which %16 shows resistance.Conclusion: M. hominis and M. genitalium were detected in 5.5% and 4.5% of samples, respectively. Our findings showed a relatively medium prevalence of M. hominis and M. genitalium in women with cervicitis in Alborz province. The sequencing results of gyrA and parC genes in this study represent the occurrence of mutations which drive fluoroquinolones resistance. Therefore, further studies are necessary in this area and to overcome this problem irregular prescribing limited and antibiotic sensitivity patterns in treatment to be considered

Evaluation of the Antibacterial and Wound Healing Properties of a Burn Ointment Containing Curcumin, Honey, and Potassium Aluminium

Burn wounds can severely trouble the health system and life quality of patients. The present study aimed to analyze the synergistic healing properties of curcumin, honey, and potassium alum substances merged in a newly-devised burn ointment on second-degree burn wounds in rats. The MIC and MBC tests on 200 clinical isolates of Pseudomonas aeruginous are compared to imipenem in vitro. Their killing time and cytotoxicity are also studied using a standard isolate of P. aeruginous, fibroblast stem cells (FSC) and mouse embryonic fibroblasts (MEF). Furthermore, histopathological and histomorphological assessments are conducted on 150 male Wistar rats whitin four experimental groups to evaluate the efficiency of the prepared burn ointment. We found a significant wound healing in both macroscopical observations and microscopical evaluations. Both curcumin and honey show strong antimicrobial effects with no cytotoxicity. Also, the histopathological results present a considerable and comparable wound re-epithelization in the a group of rats treated with both honey and curcumin after 7 days. The burn ointment containing curcumin, honey, and potassium alum show considerable efficacy in accelerating the healing of experimentally-induced burn wounds in animals. Th novel onement product is propose as a powerful alternative for the topical treatment of burn injuries

Polysemy Comprehension in Persian-Speaking Children

This paper aims to study 7 to 12-year-old Persian-speaking children’s comprehension of polysemy through semantics. The research method is descriptive-analytic, and two kinds of methodology in data collection such as documentary resources and fieldwork have been applied. For collecting data, each of the six elementary school grades course books ‘Farsi’ (2018) has been studied and all polysemous words within each of these course books have been extracted. Accordingly, to evaluate polysemy comprehension in children, a multiple-choice test containing two questions was prepared for each grade and asked 25 participants to answer in each grade and each gender from among elementary schools in Tehran. In each grade, 100 answers were received and based on the number of correct answers children’s polysemy comprehension was evaluated. These tests were administered under school authorities’ control and children had to answer in 15 minutes. The results show that most children found the polysemous words without problem only within a context and in relation to the collocated words. Also, children can comprehend the exact meaning of polysemous words based on the encyclopedic viewpoint of meaning which is rooted in human social and physical experience. Moreover, children based on their background knowledge differentiate between multiple meanings of polysemous words

Evaluation of polymyxin b susceptibility profile and detection of drug resistance genes among Acinetobacter baumannii clinical isolates in tehran, iran during 2015-2016

Acinetobacter baumannii is an important opportunistic pathogen, responsible for approximately 10 of all gram-negative nosocomial infection. The aim of this study was to determine aminoglycoside and quinolone resistance genes and their antimicrobial susceptibility profile in the clinically A. baumannii. In this cross-sectional study, a total of 100 nonduplicative A. baumannii isolates were collected from different clinical samples. Antimicrobial susceptibility test was performed by disk diffusion method. QnrA, anrB, qnrS, aac(3)-IIa, and aac(6')-Ib genes were identified using PCR method. The results of antibiotic susceptibility test showed that polymyxin B was the most effective antimicrobial against A. baumannii. 97, 95 and 82 of isolates were resistant to cefepime, ceftriaxone, and amikacin, respectively. The molecular distribution of aac(3)-IIa, aac(6')-Ib, and qnrA genes were 45, 50, and 50 of isolates, respectively. However, qnrB and qnrS genes could not be detected in any strain. This study showed that polymyxin B was the best drug against A. baumannii clinical isolates. This data is also valid for polymyxin E (colistin), which is mostly used in clinics. There is a high level of resistance genes among clinical A. baumannii isolates. This high prevalence rate highlights the necessity for the development of rapid diagnostic assays and continuous monitoring of antibiotic resistance. © 2018, Mediterranean Journal of Hematology and Infectious Diseases

Molecular typing of Brucella species isolated from humans and animals using polymerase chain reaction-restriction fragment length polymorphism technique

Background: Brucellosis is a zoonotic disease that causes major economic and public health problems. It is one of the most important diseases in humans and domestic animals. Hence, the exact identification of Brucella spp. is important for strategies of treatment and control. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) is one of the molecular techniques characterized by amplification of deoxyribonucleic acid (DNA) sequence and restriction enzyme digestion. Objectives: This study aimed at identifying genetic polymorphisms of omp2a genes among 90 Brucella isolated from humans and animals, using the PCR-RFLP method. Methods: Ninety Brucella spp. isolated from humans and animals in two different regions of Iran were used in this study. Biochemical tests and the Brucella omp2a (1100 bp) gene-PCR was used for identification of Brucella isolates. Polymerase Chain Reaction products were digested by restriction endonuclease enzyme pstI and gene sequencing analysis was carried out for molecular typing of Brucella strains. Therefore, genetic relatedness was revealed by a dendrogram. Results: Analysis of the 90 Brucella strains by biochemical tests, PCR, and PCR-RFLP methods with PstI enzyme and omp2a sequencing showed four unique RFLP Profiles (P1-P4). Seventy-nine (87.8) of the Brucella isolates belonged to B. melitensis strain 20236. From 30 animal isolates, nine (30) belonged to B. melitensis biovare1 and two (6.6) to B. abortus strain. According to the RFLP dendrogram, group 1 and 2 had higher genetic relatedness similarity. Conclusions: The results showed B. melitensis strain 20236 was the predominant strain among human and animal Brucella isolates. Likewise, according to dendrogram results, the PCR-RFLP technique was not able to separate human and animal species of B. melitensis from B. abortus. © 2018, Archives of Clinical Infectious Diseases