41 research outputs found
Plant Diversity Patterns Along Altitudinal Gradient in Understory Communities of Darkesh Region, Bojnord, Iran
The ecotone region of Darkesh with an area of 22,500 hectares is located in the Irano-Turanian xeric-continental bioclimatic zone of Khorassan-Kopet Dagh. To investigate the plant diversity patterns of understory communities along three elevation classes of 1100-1600, 1600-2100, and 2100-2600 m, 187 plots were sampled randomly and abundance and cover of species were recorded using 4-m2 plots. Beta diversity and Hill indices were calculated by using R and PAST software. A total of 252 species were recorded including 31 perennial grasses. The most abundant grasses were Poa nemoralis, Poa bulbosa, Bromus sterilis, Brachypodium sylvaticum, and Dactylis glomerata subsp. glomerata. Poa nemoralis was an important dominant grass under Quercus community. From the standpoint of species richness, Hill indices were highest under woods stories along the elevation of 1100-1600 m. Understories of oak forest and alpine communities had almost the same indices and were in the second rank compared to woods communities. Based on the β diversity index, the wood understory had the highest indices followed by Quercus and alpine communities. By increasing the elevations, the diversity of understory communities also decreased
Comparision of Aqueous and Hydroalcoholic Extracts of Foeniculum Vulgare and Carum Copticum with Gentamicin on Escherichia Coli Strains: in Vitro Study
BACKGROUND AND OBJECTIVE: Due to bacterial resistance to antibiotics, new antibacterial agents is essential. In Persian medicine Fennel (Fuenoculum vulgare Mill.) and Ajwain (Carum copticum (L.) Benth. & Hook.f.) are recommended for the treatment of some infections. In this research, bacteriostatic and bactericidal effects of aqueous and hydroalcoholic extracts of fennel and Ajwain on E. coli were investigated.
METHODS: In an in-vitro study 30 clinical isolates of urine culture of children with urinary tract infection from Amirkola Pediatric Hospital in Babol and a standard sample were used. Antibacterial effects of 4 grouos including aqueous and hydroalcoholic extracts of fennel and Ajwain by measuring the diameter of the inhibition zone using disc diffusion (concentrations 16, 32, 64, 128, 256 and 512 mg/disc) and determination of Minimum Inhibitory Concentrations (MIC) and Minimum Bactericidal Concentration (MBC) with Microdilution method was compared with Gentamicin (30mg/disc) as a positive control
FINDINGS: There was no significant difference in inhibition zone with Gentamicin at concentrations of 64, 128, 256, and 512 mg/disc in standard and clinical samples. At concentrations of 16 and 32, Gentamicin was significantly better. The extract of 512 mg/disc (12.93±2.66) of hydroalcoholic extract of Carum copticum was significantly better than 256 mg/disc (9.53±1) (p=0.002). The MIC and MBC for standard samples were 4 and 8, respectively, and for clinical samples 3.83±2.36 and 5.8 mg / ml, respectively. Other extracts were not able to inhibit the growth of Escherichia coli.
CONCLUSION: The results showed that the Hydroalcoholic extract of Carum copticum has bacteriostatic and bactericidal effects on standard and clinical isolates of Escherichia coli
The Association of cagA, vacA, babA2, babB and oipA of Helicobacter pylori with Risk of Gastric Carcinoma Development
Background & Objective: Helicobacter pylori (H. pylori), carried by more than half of the world population, is a major cause of chronic duodenal and gastric ulcers, gastritis and carcinoma. Colonization and toxin production include major virulence traits of H. pylori. The aim of this study was to assess the existence of H. pylori and virulence factors among patients with risk of gastrointestinal carcinoma (GC) in an Iraqi population.
Materials & Methods: During May 2016- October 2020 in Babylon, Iraq, a total of 500 biopsy samples were obtained from gastric tissue of patients with GC, gastritis, duodenitis, duodenal ulcer and gastric ulcer and cultured onto the Brucella agar. H. pylori isolates were identified using conventional biochemical and molecular tests. Molecular identification was conducted by amplification of glmM gene using the polymerase chain reaction (PCR) technique. The adhesin (babA2, babB and oipA) and toxin (cagA and vacA) genes were also amplified using PCR technique.
Results: Among 500 biopsy samples, 269 (110 from males and 159 from female patients) H. pylori isolates were identified. The age range of patients was 14-69 years (mean age=47.34±7.23). The babA2 and babB genes were detected in 59.47% and 59.10% of isolates, respectively. Notably, babA2 was observed in 89% of GC and 64% of DN strains being significantly more associated with GC and DN (<0.0001 and 0.028, respectively). Furthermore, babB-positive strains were significantly (0.042) more associated with PG. The rate of cagA and vacA was 44.60% and 48.32%, respectively. The cagA was detected in 64.73% of GC, and 100% of PG and DN strains with a significant association. We detected the oipA in 58.36% of strains which was significantly associated with GC (74%, P=0.0001), PG (88%, p<0.0001) and DN (84%, p<0.0001) as compared to oipA-negative strains.
Conclusion: The existence of H. pylori babA2, cagA and oipA virulence genes was associated with GC, DN and PG. As these genes play a crucial role in the development of gastric carcinoma, accurate control measure toward hindering the colonization of pathogenic strains is essential
Effects of Integration on the Cost Reduction in Distribution Network Design for Perishable Products
Perishable products, which include medical and pharmaceutical items as well as food products, are quite common in commerce and industries. Developing efficient network designs for storage and distribution of perishable products plays a prominent role in the cost and quality of these products. This paper aims to investigate and analyze the impact of applying an integrated approach for network design of perishable products. For this purpose, the problem has been formulated as a mixed integer nonlinear mathematical model that integrates inventory control and facility location decisions. To solve the integrated model, a memetic algorithm (MA) is developed in this study. For verification of the proposed algorithm, its results are compared with the results of an adapted Lagrangian relaxation heuristic algorithm from the literature. Moreover, sensitivity analysis of the main parameters of the model is conducted to compare the results of the integrated approach with a decoupled method. The results show that as the products become more perishable, application of an integrated method becomes more reasonable in comparison with the decoupled one
Antimicrobial resistance, virulence genes and genetic relatedness of Salmonella enterica serotype Enteritidis isolates recovered from human gastroenteritis in Tehran, Iran.
OBJECTIVES:
Salmonella enterica serotype Enteritidis is a major serotype associated with human salmonellosis. The main objective of this study was to determine the antibiotic susceptibility patterns and the presence of virulence-associated genes among S. Enteritidis strains isolated from patients with gastroenteritis in Tehran, Iran.
METHODS:
Over a period of 14 months (May 2015 to July 2016), 44 S. Enteritidis isolates recovered from clinical sources were characterised for antimicrobial susceptibility and virulence genes. Possible genetic relatedness among the strains was also assessed using pulsed-field gel electrophoresis (PFGE).
RESULTS:
Salmonella Enteritidis isolates showed high rates of resistance to ciprofloxacin (90.9%) and nalidixic acid (77.3%). Of the 44 S. Enteritidis isolates, 30 (68.2%) were resistant to three or more antibiotics. Twenty-two different antimicrobial resistance patterns were detected among the isolates. The most frequent resistance type was antibiotype 14 (resistance to ciprofloxacin, cefuroxime and nalidixic acid), occurring in 8 (18.2%) of the isolates. Notably, all of the isolates carried invA, sefA, sipA and sopE2 virulence genes. Furthermore, 17 virulence profiles were observed among the strains. The most common virulence profile was VP1 (n=17; 38.6%), harbouring all of the virulence genes. Two distinct PFGE patterns were observed among 44S. Enteritidis isolates. There was no association between virulence profiles or antibiotypes and PFGE clusters.
CONCLUSIONS:
Overall, this study provides valuable information on the virulence gene content, antibiotic resistance and genetic diversity of S. Enteritidis isolated from human sources in Iran.
Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.
KEYWORDS:
Antimicrobial resistance; Gastroenteritis; PFGE; Salmonella enterica serotype Enteritidis; Virulence gene
Design and construction of triplet atmospheric cold plasma jet for sterilization
In this paper, construction of triplet atmospheric plasma jet using argon, air, oxygen and nitrogen gases is reported. Bactericidal effect of the plasma jet is also investigated. To that end, longitudinal geometric configuration for the electrodes was chosen because it would increase the jet length. Electrical characteristics, jet length dependencies on the applied voltage and gas flow rate were decided, experimentally. Relative concentrations of chemical reactive species such as ozone, atomic oxygen, NOx compounds and hydroxyl were measured using optical emission spectroscopy. It was seen that atomic oxygen and ozone concentrations with triplet plasma jet are more than the concentration of single plasma jet. Triplet plasma jet was also used for sterilization of solid and liquid surfaces to disinfect gram-negative and gram-positive Escherichia coli and Streptococcus pyogenes bacteria. The results verified the effectiveness of the triplet plasma jet for killing bacteria