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Polycyclic aromatic hydrocarbons (PAHs), a class of organic pollutants, have been observed to exert deleterious effects on plant growth and various physiological processes. In this study, the effect of different concentrations of phenanthrene (0, 25, 50, 75, and 100 ppm) on growth parameters, photosynthetic pigments, some antioxidant enzymes, and some biochemical compounds of the maize plant were investigated. The experiments were conducted as pot cultures of plants under controlled conditions using a completely randomized design (CRD) with three replications for each treatment. Increasing phenanthrene concentration reduced all studied growth parameters and significantly increased photosynthetic pigment contents. Phenanthrene led to the increase in catalase, peroxidase, and superoxide dismutase activities in the roots but in shoots, only the peroxidase activity was increased. Moreover, higher phenanthrene concentrations were associated with elevated levels of malondialdehyde and hydrogen peroxide, coupled with a marked reduction in soluble sugar content in both shoot and root tissues (p<0.05). Also, increase in phenanthrene concentration in the shoots decreased the total phenol and flavonoid contents compared to anthocyanin. Phenanthrene treatment led to a significant reduction in the concentrations of lauric acid, meric acid, palmitic acid, and oleic acid in maize shoots. In conclusion, it seems that high concentrations of phenanthrene induce oxidative stress in the maize, and plants improve their enzymatic antioxidant system to moderate the stress condition. In addition, damage of cell membranes by phenanthrene leads to weakening of plants root system as well as disordering in water and nutrient uptake and finally reduction in the plant growth.
 

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Land use severely affects the carbon and nitrogen stock and the soil's physical, mechanical, hydraulic and chemical characteristics of the soil. This study aims to investigate the effect of land use type on some soil characteristics, including carbon stock (C_S), nitrogen stock (N_S), S-index, structural stability index (SSI), soil pore size distribution, soil shear strength (τ), internal friction angle (φ˚), shear cohesion (C), soil water characteristic curve (SWCC), relative field capacity (RFC), available water (AW), aeration porosity (AP) and effective porosity (P_e) in Shandiz city, Khorasan Razavi province (northeast Iran) was studied. For this purpose, 60 soil samples were taken from the surface layer (0-20 cm) in pasture and agricultural land uses. The results showed that S-Index, SSI, RFC, AW, P_e, C_s, and N_s in pasture land use were significantly higher than agricultural land use. The values of τ, C, and φ˚ in the pasture land use were significantly (p<0.01) less than the pasture land use. The relationship between soil organic carbon stock index and bulk density (r=-0.69), coarse fragments (r=-0.73), cohesion (r=-0.70), and internal friction angle (r=-0.52) were significant and negative. The amounts of carbon and nitrogen stock indices in pasture land use were 61.6 and 33.1 % greater than agricultural land use, respectively. Therefore, it can be concluded that as a result of land use change, the carbon and nitrogen stock, S-index, relative field capacity, structural stability index, available water, aeration porosity, effective porosity, and consequently, the soil quality decrease, and soil degradation increase in agricultural land use.
 

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In this research, closed-cell natural rubber foams were produced using a single-step compression molding. The effect of carbon black content on morphology, physical and mechanical properties of the foams were examined. Results showed that in this methodology, the foam density was independent of reinforcement percentage, which is a unique characteristic of single-step foams that contrasts with other previous observations. The study of curing behavior of foam compounds showed that the carbon black increasing from 0 to 30 phr increased the crosslink density (CLD) from 6.5 to 8.3*10^-5 mol/cm³, the cure rate from 16.1 to 23.2 (%/min) and the ultimate torque from 5.8 to 10.4 Nm, while, reduced curing time from 9.2 to 5.8 min. The scanning electron microscope (SEM) results showed that the reinforcement acted as a nucleation agent increasing the cell density from 8 N/cm³ to 140 N/cm³ and reducing the cell size from 579µm to 255µm. The increase of reinforcing content in the produced foams reduced the cells size and enhanced the properties of the rubber matrix. Accordingly, the modulus and hardness of the foams were increased by  0.8MPa and 40 shore A, respectively. Results of sound absorption and reflection showed that the rubber foam reflects the sound waves more than 90% and absorbs waves about 10%.

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Treatment of organic leachate is one the most controversial topics around the world which led this study to assess the efficiency of the combined oxidation and adsorption treatment (COAT) process in the treatment of leachate by considering local experiments. The removal of effluent parameters (TDS, COD, BOD) was enhanced by oxidizing the GAC surface as a catalyst with NaOH before the process and by ozone within the procedure as well. Assessing the interacting effect of operating variables (i.e., ozone concentration, GAC density, reaction time and pH) provides valuable information for optimization. Response Surface Methodology (RSM) was employed. The optimized model’s circumstances are the reaction time of 30.77 min, ozone dosage of 141.29 mg/l, pH of 7.2, and the GAC density of 1.29 gr/cm³ with the predicted removal percentage of 51.63%,62.84% and 56.13% for TDS, COD and, BOD respectively.
 

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In this study, we investigated the effectiveness of both single and hybrid systems, incorporating UV photolysis and a Moving Bed Biofilm Reactor (MBBR), for treating synthetic wastewater contaminated with petroleum hydrocarbons. Petroleum hydrocarbons pose significant environmental threats due to their high toxicity, stability, accumulation potential, and resistance to biodegradation. In the hybrid system, the wastewater underwent chemical treatment first and then was introduced into the biological reactor. For the photolysis system, we explored the impacts of different concentrations and various radiation powers of UV-C lamps. Optimal conditions were determined to be a Chemical Oxygen Demand (COD) of 350 mg/L and a radiation power of 80 W. In the MBBR system, various concentrations were introduced into the reactor, achieving a maximum removal efficiency of 85% for an initial COD of 1000 mg/L over 72 hours with a 50% filling capacity. In the hybrid system, we achieved a remarkable hydrocarbon removal efficiency of 99% after 123 hours. Although the operational time of the hybrid system was relatively long, it demonstrated itself as a suitable treatment process compared to other conventional methods for removing these challenging, hard-to-biodegrade compounds.

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A 4 × 4 factorial design was conducted to quantify the optimumrncarbohydrate ⁄ lipid ratio to minimize the dietary protein level in growingrnbeluga, Huso huso (initial weight 891.9 ± 33.4 g, mean ± SD). Fish were fedrnwith sixteen experimental diets formulated to contain four protein levels (35,rn40, 45 and 50%) and four dietary carbohydrate ⁄ lipid ratios of 0.8, 1.1, 1.4,rnand 1.7 for 108 days. At the end of trial, there were no significant differencesrnin growth parameters among fish fed with 35, 40 and 45% protein levels. Nornsignificant difference in growth parameters and feed efficiency (FE) wasrnalso observed when dietary carbohydrate ⁄ lipid ratios decreased from 1.7 torn1.1 within the same energy level (P > 0.05). The highest carcass proteinrncontent was observed in fish fed 0.8 and 1.4 carbohydrate to lipid ratio (P

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Background: L-lysine is essential amino acid for human and animal nutrition. L-lysine is useful as medicament, chemical agent, food material (food industry) and feed additive (animal food). The industrial production of lysine has become an economically important industrial process. Several hundred thousands tones of L-lysine are produced annually worldwide, almost exclusively using Corynebacterium glutamicum. Study methods: To amplify LysA gene from C.glutamicum, two primers with NheI and HindIII restriction sites were designed. PCR was performed and PCR product was ligated with pTZ57R/T. Recombinant plasmid sequence was determined. LysA with sticky end was ligated with digested pET28a vector and ligation mixture was transformed in E.coli BL21(DE3). The recombinant plasmid was isolated with enzymatic digestion and sequencing. Results: LysA gene, a fragment with 1.3 kb, was cloned. PCR products and enzymatic digestion of extracted vectors with HindIII and NheI, sequencing and SDS-PAGE confirmed the authenticity of cloning. Recombinant bacterial colonies were investigated and confirmed by two methods (PCR and enzymatic digestion). Conclusion: In this study for the first time, the expression rate of Meso- diaminopimelate decarboxylase enzyme (EC 4.1.1.20) in this expression vector was investigated and was increased significantly.

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  Background : Type 1 diabetes mellitus (T1DM) is an autoimmune disease characterized by selective destruction of pancreatic beta cells.   Methods: The study included 80 children, 20 of them have T1DM, 40 children were selected from first degree relatives to the same child and 20 healthy children serve as control. Body mass index (BMI) was calculated, random blood glucose and glycosylated hemoglobin A1c (GHbA1c) were measured. The following biochemical markers were measured in sera of all subjects by ELISA kits: Human insulin ,C-peptide, human islet cell antibody (ICA), insulin auto antibodies (IAA) and antiglutamic acid decarboxylase (anti-GAD) antibodies. Results : This study showed that diabetic children had high level of ICA (65%), IAA (55%), anti-GAD antibodies (50%) and decrease in C-peptide (60%). Whereas the relatives showed high level of anti-GAD antibodies (30%), IAA(25%), ICA(2.5) and decrease in C-peptide (30%). Anti-GAD antibodies were significantly higher among the relatives of the diabetics compared to the healthy controls. Conclusions : The strongest predictors of diabetes were C- peptide and islets cell antibodies, which had odd ratio 4.7 and 3.1, respectively. Autoantibodies could distinguish T1DM patients from healthy control subjects and they may also identify individuals at high risk during progression from pre-diabetes to overt disease.

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The melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is one of the most important pests of agricultural products in Iran. In this study, susceptibility of melon aphid that collected from seven regions (Yazd, Varamin, Mohammadshahr, Esfehan, Karaj, Hashtgerd and Ramsar) was compared to pirimicarb and malathion after 24 hours in 2009. Bioassay experiments on adults were carried out by using leaf dipping method on squash (Cucurbita pepo) leaf in different concentrations of insecticides in laboratory conditions (25 ± 0.2 ºC, 60 ± 5%, 16: 8 [L: D] h). Control treatment was dipped in distilled water. Each test was replicated three times. The results showed that LC₅₀ values of malathion for Ramsar, Karaj, Mohammadshahr, Hashtgerd, Varamin, Esfehan, and Yazd populations were 162.99, 159.19, 117.94, 79.96, 38.81, 36.32, and 20.25 ppm, respectively. Also, LC₅₀ values of pirimicarb for Yazd, Mohammadshahr, Kararj, Hashtgerd, Ramsar, Esfehan, and Varamin populations were 1414.16, 1359.34, 1057.62, 970.33, 881.87, 806.14, and 601.98 ppm, respectively. According to results, aphids of Varamin and Yazd populations had the most susceptibility to pirimicarb and malathion, respectively. Also, aphids of Yazd and Ramsar populations had the least susceptibility to pirimicarb and malathion, respectively. Regarding the fact that Yazd and Ramsar populations had the least susceptibility to pirimicarb and malathion, respectively, there is a possibility that melon aphids in these regions are susceptible to other organophosphate and carbamate (similar mode of action) pesticides. Therefore, in the pest management program, careful chemical control measures for melon aphid in these regions is recommended.  

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The current study is based on synthesis a low cost carbon aerogel with improved properties and thermal insulator approach. In this work cheap novolac resin are used as a raw material for producing polymer aerogel by ambient drying method; then the coal tar pitch is added to samples by immerging them in pitch solution. In next step novolac-pitch polymer aerogels is converted to carbon nano-structure aerogels by pyrolysis heat treatment at inert atmosphere. The results proved, nano-structured aerogels with predictable density will be achieved by this method; also by studying on microstructure and morphology of aerogels it founded these aerogels have high porosity, low density(about 0.1-0.4 g/cm3) and high specific surface area (about 600 m2/g). The charring pitch was a lot and using of it made improved thermal properties that resulted in at least 100s delay in increasing temperature in time-temperature history test; as a result a high performance thermal insulator achieved.

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The toxicity of imidacloprid and pirimicarb for all stages of the melon aphid, Aphis gossypii Glover, were investigated under laboratory conditions (25 ± 1 ^oC, 65 ± 5% R.H. and a photoperiod of 16:8 (L: D) h.) using a leaf dipping method. These pesticides were very toxic for first instar nymphs of A. gossypii with LC₅₀ values of 17 and 220.2 ppm for imidacloprid and pirimicarb, respectively. For other nymphal instars, values of 23.9 to 70.5 ppm and 308.8 to 781.7 ppm were recorded for imidacloprid and pirimicarb respectively. Their LC₅₀ values for adults were 90.1 and 983.1 ppm, respectively. Toxicity decreased with increasing age. Imidacloprid was more toxic than pirimicarb for all stages of development. The effect of applying sublethal concentrations of imidacloprid and pirimicarb was evaluated, also, using demographic toxicology. Longevity and population growth parameters, including intrinsic rate of increase (r_m), net reproductive rate (R₀), generation time (T_c) and finite rate of population increase (λ), were affected negatively by both insecticides. The r_m values for control, imidacloprid and pirimicarb exposed populations were 0.438, 0.150 and 0.335 female offspring per female per day, respectively. The doubling time (DT) also, was affected by imidacloprid. Overall, these results suggest that imidacloprid and pirimicarb can be effective against A. gossypii.  

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Projected global climate change may have a major influence on crop yield. The likely effects of climate change caused by increasing atmospheric carbon dioxide levels on rice yield in Iran were evaluated using a mechanistic growth model for rice, GSAC-rice, running under a climate change scenario predicted for a doubled-CO2 (2xCO2) atmosphere by the Geophysical Fluid Dynamics Laboratory (GFDL) General Circulation Model (GCM). Simulations were run for two locations with contrasting climates, one in the north (Rasht) and one in the south (Ahwaz) of Iran. GFDL predicted that as a result of doubling CO2 , temperature increases by 4.5 and 4.6 0C during the rice growing season in Rasht and Ahwaz, respectively. Changes in solar radiation are minor, but rainfall during the rice growing season decreases by 38.8% (102 mm) for Rasht and 68.2% (5.8 mm) for Ahwaz. It was predicted that doubling [CO2] alone increased rice yield by 30%, but that yield decreases by 3.7 and 11.6% for each degree centigrade rise in temperature in Rasht and Ahwaz, respectively. As a result of the combined effect of both doubling [CO2] and the climate change accompanying it (predicted with GFDL), 8% greater rice could be produced in Rasht, but irrigation needs would be increased dramatically by 57%. In Ahwaz (the south of Iran), rice production could be halved and might not even remain a viable option unless plant breeders are able to produce more heat tolerant rice cultivars. It was concluded that rice production in the north and south of the country would change dramatically.

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The ladybird beetle, Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae) is one of the most important natural enemies of the common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae). The effects of hexaflumuron and spirodiclofen were investigated on development and carbohydrates and total lipid contents of 4^th instar larvae of H. variegata. The insecticides had significant effects on the mortality of eggs, but no significant effects on mortality of larvae or pupae. Hexaflumuron significantly increased the length of development of eggs (2.89 days) and first instar larvae (3.28 days), but had no significant effects on other instars or pupae. Spirodiclofen had no significant effects on developmental stages of H. variegata. Glycogen content was significantly reduced by spirodiclofen (17.42 mg/g fresh body weight) and hexaflumuron (16.07 mg/g fresh body weight). Trehalose content in hexaflumuron (1.89 mg/g fresh body weight) and spirodiclofen-treated larvae (2.02 mg/g fresh body weight) was significantly lower than control (8.01 mg/g fresh body weight). Glucose content in spirodiclofen-treated larvae (0.96 mg/g fresh body weight) was significantly higher than in hexaflumuron-treated larvae (0.24 mg/g fresh body weight) and control (0.15 mg/g fresh body weight). Significant reduction in the amount of lipid was observed in spirodiclofen-treated larvae (5.29 mg/g fresh body weight), but not in hexaflumuron-treated larvae (7.11 mg/g fresh body weight). These results suggest that substantial physiological events in the life of larvae are affected in response to the action of the tested insecticides.  

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The enhancement of energy consumption and increasing demand for oil have led to using improve oil recovery methods. Chemical enhanced oil recovery methods are among the most widly used techniques. Generally, the effect of these methods has been less than the predicted amounts by the studies. One of the leading causes, could be due to the loss of chemicals by adsorption or precipitation of the surfactants on the rock surface. The mineralogy of the reservoir rocks is effective in determination of the interaction between the bulk of the fluid phase and rock surface. This effect will change in the surface charge of the adsorbent and wettability alteration of the rocks.
Research subject: In this study, the adsorption of AOT surfactant on the surface of a hydrophilic adsorbent of carbonate reservoir was investigated. For this purpose, after the preparation of rock and fluid samples, the adsorption of surfactant was investigated in concentrations below and above the CMC.
Research approach: Batch adsorption experiments were conducted to measure the amount of surfactant adsorption on the surface of carbonate rock. First different concenteration of AOT solutions and carbonate rock as adsorbent were combined. After 48h, the equilibrium concentrations were determined by using the calibration curve and. The amount of surfactant adsorption can be calculated by knowing the maqnitudes of  equilibrium and initial concentration of the surfactant.

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The toxicity of thiamethoxam and pirimicarb on Diaeretiella rapae (Mc'Intosh) as a parasitoid of Lipaphis erysimi (Kaltenbach), exposed to residues on glass vials, was investigated under laboratory conditions at 23 ± 2 °C, 70 ± 5% RH and 16:8 h (L: D). Moreover, in order to find the negative impacts of both insecticides on the efficiency of D. rapae, the functional response of the exposed parasitoids were assessed. The newly emerged parasitoids were exposed to LC₂₅ of the insecticides and distilled water as control. Host densities of 2, 4, 6, 8, 16, 32 and 64 were placed on canola seedlings in a transparent cylindrical container and were offered to the treated parasitoids. Type of functional response was determined by means of logistic regression method and the parameters, attack rate (a) and handling time (T_h) were calculated by nonlinear regression model using SAS software. The parasitoid exhibited type II functional response in all experiments. Attack rates in control, pirimicarb and thiamethoxam were 0.057 ± 0.01,0.059 ± 0.013 and 0.040 ± 0.01 h^-1, and handling times were 1.097 ± 0.1, 1.86 ± 0.02, 2.81 ± 0.296 h, respectively. Maximum rates of parasitism (T/T_h) were estimated 21.87, 12.9, 8.53 aphids, respectively. These observations suggest that pirimicarb with less harmful effects is the preferred candidate for controlling the mustard aphid.

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Background: Escherichia coli (E. coli) strains are among predominant agents causing nosocomial and community acquired infections. The majority of strains encode numerous virulence factors including fimbrial adhesions, secretory proteins and toxins, siderophores, and capsule. This study aimed to investigate the prevalence rate of virulence encoding genes and carbapenem resistance-encoding genes among imipenem-resistant E. coli isolates collected from patients hospitalized in Tehran, Iran.
Materials and Methods: In this cross-sectional study (April 2015-December 2017), 50 non-duplicated carbapenem-resistant E. coli isolates were collected from clinical specimens (stool, urine, blood, and wound) of hospitalized patients in three hospitals in Tehran, Iran. The antibiotic susceptibility profile was determined against 15 antibiotics on Mueller Hinton Agar (MHA) as per CLSI guidelines version 2016. The PCR was used to detect virulence and antibiotic resistance encoding genes.
Results: From a total of 50 carbapenem-resistant E. coli isolates, the highest resistance rate was observed to ceftazidime (100%), tetracycline (88%), amoxicillin (100%), sulfonamide (60%), and the least resistance rate was observed against amikacin (14%), gentamicin (22%), and fosfomycin (0%). The genes mediating resistance were as follows: beta-lactams OXA-48 (8%), IMP (16%), VIM (0%), NDM-1 (0%),  fosA3 (0%), quinolones (qnrA 48%), and colistin mcr-1(0%). Furthermore, the prevalence rates of of fimA, hlyA, cnf1, vat, pic, crl, and papH were 88, 36, 28, 10, 12, 54, and 88%, respectively.
Conclusion: In this study, all imipenem-resistant E. coli isolates were susceptible to fosfomycin, and all were  fosA3 negative. Among carbapenemase genes, IMP and OXA-48 type enzymes associated with higher MIC levels (8 to 32 µg.mL^-1) were detected. In this study, data suggest the role of these carbapenemases in resistance to carbapenems. Furthermore, the presence of multiple drug resistant strains encoding adhesive and secretory virulence factors is a concern for the infections treatment. 

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Adequate calcium ( Ca ) intake during the crucial growing years maximizes peak bone mass and thus delays the onset of osteoporosis later in life. In addition, Ca plays a protective role against essential hypertension and colorectal cancer. Dairy products, a naturally rich Ca source, are the major source of Ca in our diet. However many people avoid consuming milk, because of economical problems and who are lactose intolerant. For these people, Cafortified nondairy foods can be a significant source of Ca. A number of foods, including bread, staple food, can be fortified with Ca. In this study, formulation and production of fortified Barbari bread with different Ca sources was investigated. In order to, different kind of Barbari breads were prepared with flour fortified with two food-grade inorganic Ca sources such as Ca carbonate and Ca sulfate. Ca was added to flour at two levels: 500 and 1000 mg/ 100 g of flour. one bread was also prepared using ordinary flour. Results of Farinograph and Extensograph tests indicated strength of dough. Results of Farinograph test indicated that the percent of absorbed water, dough development time, dough stability and valorimeter value will increase by adding Ca, while the degree of dough softening in 10 and 20 minates, will reduce. Also atomic absorption spectrophotometry test showed that retaining of Ca in breads was significant ( P< 0.01).CaCO3 and CaSO4 are preffered sources of Ca for the fortification of cereal-based foods as they had no adverse affect on bread quality but CaCO3 is higher in Ca than CaSO4. It is also less expensive. For these reasons, Ca carbonate is a preffered Ca source for fortifying bread.

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Ongoing climate change has been a major global challenge since the 1880s. Sequestration of carbon(C) in rangelands ecosystems could provide a net carbon sink to offset increases in atmospheric C in global scale. This research is aimed at estimating the above-ground biomass carbon sequestration potential in Iran. For this purpose, total rangelands area and productivity data were extracted from the annual reports of Agriculture Statistical Pocketbook (2006-2013) of the country. Then productivity data was used to calculate above-ground C storage per province. The maximum and minimum rangeland areas were observed in Sistan and Baluchestan and Mazandaran (Nowshahr) Provinces, respectively. Maximum above-ground biomass C storage was about 1.07 Mg Cha^-1y^-1 in Fars Province. The minimum amount occurred in Qom province with only 0.023Mg C ha^-1 y^-1. In summary, mean carbon CO₂fixation was about 0.25 Mg C ha^-1 y^-1in Iran’s rangelands from 2003 to 2013. Considering the total rangeland area(≈ 84.8 million hectare) and productivity of Iran, 11770.011 Gg C y^-1 carbon is stored in above-ground biomass annually providing at least 5885 Gg organic C sequestration potential.

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Aims: Klebsiella pneumoniae is a Gram-negative opportunistic pathogen. The carbapenems are effective therapeutic choice for the treatment of Klebsiella pneumonia infections. Carbapenemases are a group of enzymes capable of hydrolyzing carbapenems. This study was to introduce phenotypic and genotypic methods to identify the carbapenemase-producing isolates of Klebsiella pneumoniae.
Materials & Methods: this study was to introduce phenotypic and genotypic methods to identify the carbapenemase-producing isolates of Klebsiella pneumoniae. The Modified Hodge Test (MHT) was performed to determine the susceptibility of isolates to antibiotics. The final products of PCR were electrophoresed on agarose gel.
Findings: The highest rate of resistance were observed for piperacillin (84%) and the lowest for ertapenem (50%). The majority of MHT positive isolates was from urine (64.7%), while abdominal and cerebrospinal fluids (0%) were the lowest. In addition, the ICU wards with 47 (69.1%) and the emergency units with 4 (5.9%) samples, had the most and the least frequent cases, respectively. MHT was positive in 68 K. pneumoniae isolates, but none of them were positive for blaKPC gene.
Conclusion: The blaKPC gene has low prevalence in the Isfahan City, Iran.

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Aims: Infections by extended-spectrum beta-lactamase (ESBL) and carbapenemase-producing Enterobacteriaceae (CPE) are increasing problems in pediatrics and are usually associated with higher hospital costs and mortality rates. The aims of this study were the statistical investigation of the worldwide prevalence and risk factors of ESBL and CPE family members among pediatric population.
Instruments and Methods: From October 1, 1995 to July 27, 2017, some keywords including “ESBLs”, “carbapenemase”, “pediatrics”, “children”, and “risk factor” were searched in the searching databases such as Google Scholar, Embase, Scopus, PubMed, and Web of Science among original research articles. The univariate and multivariate analysis of the collected data was performed by Graph Pad Prism 6.1 software.
Findings: The mean percentage of ESBL production was 20.23±22.31 and the mean percentage of CPE was 1.81±2.77. E. coli (n=991) and K. pneumonia (n=627) were the predominant ESBL-producers. Nephrology (n=5005) and NICU (n=1805) were predominant hospital wards. ESBL-PE had significantly higher prevalence in the infants unit (OR=0.9832, 95% CI=12.271-19.519; p<0.001). Moreover, ICU ward was a significant and independent risk factor for CPE acquisition (OR=0.849, 95% CI=2.211-5.415; p=0.0035). ESBL-PE and CPE were significantly isolated from blood samples (OR=0.9276, 95% CI=1.508-2.433, p<0.0001) and fecal specimens (OR=0.968, 95% CI=2.829-5.133, p<0.0001), respectively.
Conclusion: Most of risk factors between ESBL-PE and CPE are similar including previous hospitalization and prolonged use of antibiotics, cephalosporins, and previous colonization. Other possible potential risk factors that should be considered include presence of catheters and travel history. Detection of risk factors provides useful information for formulation of infection control policy.