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Showing 2 results for Nayeri
In vitro Susceptibility Study of Salmonella typhimurium Mutant to Stress Factors
Ania Ahani Azari , Taghi Zahraei Salehi , Bahar Nayeri Fasaei ,
Volume 10, Issue 6 (Nov-Dec-2016 2016)
Abstract

ABSTRACT

        Background and Objective: In this study, we compared the susceptibility of Salmonella typhimurium phoP mutant and its parent to stress conditions that the pathogen may encounter in a host.

        Methods: For this purpose, we used the phoP deletion mutant constructed in our previous study. In order to test the in vitro susceptibility of the mutant to stress factors, the effect of acidic pH, heat, bile salts and polymyxin on growth of the mutant was examined. Then, minimum inhibitory concentration and minimum bactericidal concentration of bile salts and polymyxin were determined. Salmonella typhimurium 14028 was used as the parent strain.

         Results: The mutant was highly susceptible to bile salts and polymyxin in comparison with the parent strain, but no difference was observed in their susceptibility to acid and heat.

          Conclusion: This study confirms the role of the phoP in resistance of Salmonella to polymyxin and bile salts. Mutation in the phoP leads to susceptibility of the mutant to bile and cationic antimicrobial peptides.

         Keywords: In vitro, Mutant, Salmonella typhimurium, Disease Susceptibility.


Cerium interfering effect on iron intestinal absorption in rats using the Everted Gut Sac (EGS) method
Fereshteh Hematyar Tabatabaie , Ali Asghar Moshtaghie, Ali Asghar Rastegari, Hashem Nayeri,
Volume 18, Issue 2 (Mar-Apr 2024)
Abstract
Background: Certain trace elements, like cerium, have the potential to disrupt iron metabolism. This study explored the impact of cerium on intestinal iron absorption, focusing on the initial stage of iron metabolism. We employed the rat everted gut sac (EGS) segments to assess the interference caused by cerium. The primary objectives of this study were to examine the absorption of cerium in the intestines and to compare iron absorption in the presence and absence of cerium.
Methods: For the EGS experiment, segments of the rat's duodenum, ileum, or jejunum were promptly excised, cut into 5-6 cm segments, and rinsed with a physiological solution. These freshly prepared rat EGS segments were then incubated in Earle's medium containing iron (III) and/or cerium (III). We examined the impact of ascorbic acid, glucose, and different time intervals on the intestinal absorption of cerium and iron. Specifically, we investigated how glucose (5 mM) and ascorbic acid (2.8 mM) affected the absorption of cerium and iron at various concentrations (ranging from 0 to 200 mg/L). Additionally, we assessed the interfering effect of cerium on iron absorption.
Results: The results indicated that the maximum intestinal absorption of Fe (III) and Ce (III) occurred at a concentration of 200 mg/L. Furthermore, it was observed that their uptake increased following the reduction by ascorbic acid. The absorption of these elements also rose in the presence of glucose, suggesting energy-dependent transport. Additionally, a consistent cerium concentration was found to decrease iron absorption by 24.3% (P ≤ 0.05).
Conclusion: Based on the results, cerium likely reduces iron uptake by competing with iron. Cerium can also disrupt iron metabolism and lead to iron-related metabolic disorders. However, further studies at the molecular and intracellular levels are needed to gain a better understanding of this mechanism.
 
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