The correlation between biofilm formation capability and antibiotic resistance pattern in Pseudomonas aeruginosa

The infections caused by Pseudomonas aeruginosa are life-threatening, due to high intrinsic antimicrobial resistance of this microorganism. The integrons and biofilm formation of P. aeruginosa have a significant role in antibiotic resistance. Therefore, this study aimed to evaluate antibiotic resistance pattern in Pseudomonas aeruginosa isolates with biofilm formation ability. This cross-sectional study from January 2017 to December 2017 was conducted on 78 isolates (58 clinical and 20 environmental) of P. aeruginosa recovered from the 547 samples (439 of clinical and 108 of environmental samples). The isolates were identified by phenotypic and genotypic tests. Kirby-Bauer disk diffusion method was used for susceptibility testing. The prevalence of class 1, 2 and 3 Integrons, rhlA, and lasB genes were determined using Polymerase Chain Reaction (PCR). Biofilm formation was determined using the microtiter plate method. Data analyzed using Stata 14 software and Chi-Square test. The most prevalent resistance was observed against Ticarcillin/Clavulanic Acid (55). Generally, 56.4 of isolates were producers of strong biofilm in both environmental and clinical isolates. The prevalence of strong biofilm producers in clinical isolates was more than environmental. A significant correlation was observed between Int1, Int2, and rhlA genes with biofilm formation capability (P = 0.02). Regarding >50 of both environmental and clinical isolates were producers of strong biofilm and because the source of clinical isolates may be from the environment, the necessary hygiene measurements should be taken. No significant correlation was observed between lasB gene with biofilm formation capability. © 2019 Elsevier Inc

Survey of abundance and distribution of rocky shore Polychaeta from the Hormonz Island in Persian Gulf

Polychaeta are the most important benthic animals and consist of many species with a vital role in food web. We conducted a survey from summer 2005 to spring 2006 to complete the ecological studies of macrobenthos in rocky shores of the intertidal zone of the Hormouz Island. Three main regions were studied in the west, south and south-eastern parts and three transects were sampled in each region to test variation in Polychaeta distribution and abundance along the entire intertidal zone. At each one of the nine transects the shore was levelled and a general qualitative description was made, which also aided in the stratification of subsequent quantitative sampling. Samples were fixed in %4 formalin and transported to lab for analysis. Results showed presence of 10 genera of Polychaeta among which Nereis was the most abundant in the intertidal rocky shores. Our study also revealed seasonal and zonal distribution of Polychaeta in rocky shores of the area. Abundance of Polychaeta was markedly higher in summer compared to winter and in the upper zone compared with the mill-littoral zone. Results of Shannon and Simpson diversity indexes affirmed above conclusion

Interacting viscous ghost tachyon, K-essence and dilaton scalar field models of dark energy

We study the correspondence between the interacting viscous ghost dark energy model with the tachyon, K-essence and dilaton scalar field models in the framework of Einstein gravity. We consider a spatially non-flat FRW universe filled with interacting viscous ghost dark energy and dark matter. We reconstruct both the dynamics and potential of these scalar field models according to the evolutionary behavior of the interacting viscous ghost dark energy model, which can describe the accelerated expansion of the universe. Our numerical results show that the interaction and viscosity have opposite effects on the evolutionary properties of the ghost scalar filed models.Comment: 16 pages, 17 figure

Inhibitory Effects of Several Essential Oils towards Salmonella typhimurium, Salmonella paratyphi A and Salmonella paratyphi B

Plant essential oils are natural products extracted from plants and because of their antimicrobial properties can be used as natural additives in foods. They are also useful for decontamination of food-borne pathogens and can be a safe additive in foods. The antimicrobial activities of essential oils belonging to Saturiea hortensis, Thymus vulgaris, Mentha polegium, Cuminum cyminum, Lavandula officinalis and Mentha viridis L. (spearmint) were investigated at different concentrations (0.1, 0.3, 0.5, 1, 2, 5 and 10%v/v) against Salmonella typhimurium, Salmonella paratyphi A and Salmonella paratyphi B by using the agar well diffusion method. Essential oils showed inhibitory effect on Salmonella spp. in the agar well diffusion assay. In addition, the capability of essential oils for decontamination of minced row beef, ground beef, minced raw chicken and minced raw fish inoculated with Salmonella spp. at 0.1 and 0.5%v/v were assessed. Reduction of the Salmonella spp. population was observed following the inoculation of the cultures with 0.1 and 0.5%v/v essential oils

Essential Oil Variability of Superior Myrtle (Myrtus communis L.) Accessions Grown under Same Conditions

Myrtle (Myrtus communis L., Myrtaceae) has numerous applications in pharmacology, food technology, and cosmetic industry. The current research aimed at measuring variations in the leaf essential oil (EO) compositions of 14 superior myrtle accessions originating in natural habitats of south Iran. The plants were grown under greenhouse conditions. Fresh leaf samples were harvested in June 2021. Based on dry matter, the extractable amount of EO in the accessions ranged from 0.42% (BN2) to 2.6% (BN5). According to GC/MS analysis, the major compounds in the EO were α-pinene (2.35–53.09%), linalyl acetate (0–45.3%), caryophyllene oxide (0.97–21.8%), germacrene D (0–19.19%), α-humulene (0–18.97%), 1,8-cineole (0–18.0%), limonene (0–17.4%), and p-cymene (0–13.2%). These myrtle accessions were classified into four groups, including I: caryophyllene oxide/germacrene D/α-humulene/methyl eugenol chemotype; II: α-pinene/p-cymene/α-humulene and (E)-β-caryophyllene; III: α-pinene/1,8-cineole, and linalool; IV: linalyl acetate/γ-terpinene/1,8, cineole/limonene. These classifications were established by considering the main EO components using hierarchical cluster analysis (HCA) and principal component analysis (PCA). In summary, this study provided new insights into available opportunities of selecting suitable genotypes for commercial cultivation purposes and planning breeding programs in the future

Earthquake risk assessment using an integrated Fuzzy Analytic Hierarchy Process with Artificial Neural Networks based on GIS: A case study of Sanandaj in Iran

Earthquakes are natural phenomena, which induce natural hazard that seriously threatens urban areas, despite significant advances in retrofitting urban buildings and enhancing the knowledge and ability of experts in natural disaster control. Iran is one of the most seismically active countries in the world. The purpose of this study was to evaluate and analyze the extent of earthquake vulnerability in relation to demographic, environmental, and physical criteria. An earthquake risk assessment (ERA) map was created by using a Fuzzy-Analytic Hierarchy Process coupled with an Artificial Neural Networks (FAHP-ANN) model generating five vulnerability classes. Combining the application of a FAHP-ANN with a geographic information system (GIS) enabled to assign weights to the layers of the earthquake vulnerability criteria. The model was applied to Sanandaj City in Iran, located in the seismically active Sanandaj-Sirjan zone which is frequently affected by devastating earthquakes. The Multilayer Perceptron (MLP) model was implemented in the IDRISI software and 250 points were validated for grades 0 and 1. The validation process revealed that the proposed model can produce an earthquake probability map with an accuracy of 95%. A comparison of the results attained by using a FAHP, AHP and MLP model shows that the hybrid FAHP-ANN model proved flexible and reliable when generating the ERA map. The FAHP-ANN model accurately identified the highest earthquake vulnerability in densely populated areas with dilapidated building infrastructure. The findings of this study are useful for decision makers with a scientific basis to develop earthquake risk management strategies

The generalized second law of gravitational thermodynamics on the apparent horizon in f(R)-gravity

We investigate the generalized second law (GSL) of thermodynamics in the framework of $f(R)$-gravity. We consider a FRW universe filled only with ordinary matter enclosed by the dynamical apparent horizon with the Hawking temperature. For a viable modified gravity model as $f(R)=R-\alpha/R+\beta R^{2}$, we examine the validity of the GSL during the early inflation and late acceleration eras. Our results show that for the selected $f(R)$-gravity model minimally coupled with matter, the GSL in the early inflation epoch is satisfied only for the special range of the equation of state parameter of the matter. But in the late acceleration regime, the GSL is always respected.Comment: 10 pages, accepted by Europhys. Lett. 201

Interacting entropy-corrected new agegraphic dark energy in Brans-Dicke cosmology

Motivated by a recent work of one of us [1], we extend it by using quantum (or entropy) corrected new agegraphic dark energy in the Brans-Dicke cosmology. The correction terms are motivated from the loop quantum gravity which is one of the competitive theories of quantum gravity. Taking the non-flat background spacetime along with the conformal age of the universe as the length scale, we derive the dynamical equation of state of dark energy and the deceleration parameter. An important consequence of this study is the phantom divide scenario with entropy-corrected new agegraphic dark energy. Moreover, we assume a system of dark matter, radiation and dark energy, while the later interacts only with dark matter. We obtain some essential expressions related with dark energy dynamics. The cosmic coincidence problem is also resolved in our model.Comment: 16 pages, no figure, accepted for publication in Gen. Relativ. Gra

Reconstructing interacting new agegraphic polytropic gas model in non-flat FRW universe

We study the correspondence between the interacting new agegraphic dark energy and the polytropic gas model of dark energy in the non-flat FRW universe. This correspondence allows to reconstruct the potential and the dynamics for the scalar field of the polytropic model, which describe accelerated expansion of the universe.Comment: 9 page