عنوان

ارزیابی خواص ضدمیکروبی آب فعال شده با پلاسمای غیرحرارتی هوا بر اشریشیا کلی و استافیلوکوکوس اورئوس

شماره

پ۲۵۷۵۴

زبان متن نوشتاري يا گفتاري و مانند آن

per

عنوان اصلي

ارزیابی خواص ضدمیکروبی آب فعال شده با پلاسمای غیرحرارتی هوا بر اشریشیا کلی و استافیلوکوکوس اورئوس

نام نخستين پديدآور

شیما شکرزاده

نام ناشر، پخش کننده و غيره

علوم طبیعی(پردیس)

تاریخ نشرو بخش و غیره

۱۴۰۰

نام خاص و کميت اثر

۱۳۱ص.

مواد همراه اثر

سی دی

جزئيات پايان نامه و نوع درجه آن

کارشناسی ارشد

نظم درجات

میکروبیولوژی گرایش میکروب‌های بیماریزا

زمان اعطا مدرک

۱۴۰۰/۰۶/۳۰

متن يادداشت

افزایش ظهور مقاومت آنتی‌بیوتیکی در بین باکتری‌ها به خصوص باکتری‌های عامل عفونت‌های بیمارستانی به یک خطر جدی در بهداشت عمومی تبدیل شده است. این امر محققان را به فکر ابداع روش‌های جدید درمانی برای مقابله با این باکتری‌ها انداخته است. یکی از این تکنیک‌های جدید استفاده از پلاسما برای ضدعفونی سطوح و حتی زخم‌های عفونی شده با باکتری‌های مقاوم می‌باشد. پلاسما از نظر تعادل دمایی و ترمودینامیکی به دو نوع پلاسمای حرارتی و غیرحرارتی می‌باشد. پلاسمای غیرحرارتی یا سرد به دلیل دمای پایین، بهترین روش برای ضدعفونی سطوح حساس به حرارت و زخم‌ها می‌باشد. یکی از روش‌های استفاده از پلاسمای سرد، به کارگیری آب فعال شده توسط پلاسما (PAW) می‌باشد. این آب که تحت عنوان آب تیمار شده با پلاسما هم خوانده می‌شود، یک محیط اسیدی با گونه‌های واکنش‌گر اکسیژن و نیتروژن می‌باشد که به آب خاصیت ضدمیکروبی اعطا می‌کند. به طوری ‌که مجاورت باکتری‌ها با آب تیمار شده با پلاسما منجر به غیرفعال شدن آن‌ها می‌گردد. ولی مکانیسم‌های غیرفعال‌سازی هنوز کاملا شناسایی نشده‌اند.هدف از انجام این مطالعه بررسی نوع و غلظت گونه‌های فعال تولید شده در آب پس از پلاسمادهی، ارزیابی اثر ضدمیکروبی آب فعال شده با پلاسما و ماندگاری این اثر برحسب زمان و مطالعه راه‎‌های احتمالی مقاومت باکتری در برابر استرس ایجاد شده توسط این آب فعال می‌باشد.

متن يادداشت

Abstract:Increasing the emergence of antibiotic resistance bacteria, especially those that cause nosocomial infections, has become a serious risk in public health. This has led researchers to think about new treatments to fight these bacteria. One of these new techniques is the use of plasma to disinfect surfaces and even wound infections caused by resistant bacteria. There are two types of plasma based on temperature and thermodynamic equilibrium: thermal and non-thermal plasma. Non-thermal plasma or cold plasma is the best method for disinfection of heat sensitive surfaces and wounds because its temperature is low. One way to use of cold plasma is use of plasma-activated water (PAW). This water, also known as plasma-treated water, is an acidic environment with reactive oxygen and nitrogen species (RONS). This RONS gives antimicrobial properties to water. So that exposure of bacteria to plasma activated water leads to their inactivation. But the inactivation mechanisms have not been fully identified yet.The aim of this study was to investigate the type and concentration of reactive species produced in water after plasma treatment, to evaluate the antimicrobial effects of plasma activated water and its durability in terms of time and a study of possible ways of bacterial resistance to stress caused by this active water. In this study, gliding arc plasma at atmospheric pressure was used to produce plasma activated water. The type and concentration of reactive species produced by plasma in different conditions were evaluated. The antimicrobial effects of plasma activated water on Escherichia coli (gram negative) and Staphylococcus aureus (gram positive) was investigated. The half-life of antimicrobial properties of plasma-activated water was evaluated at different temperature and the expression of genes encoding oxidative enzymes in bacteria was examined after treated by PAW.Investigation of plasma activated water properties in different conditions showed that the acidity and concentration of reactive species produced in PAW can vary depending on the amount of voltage used and time of plasma exposure. Contrary to the expected results in this study, gram-negative bacteria (E. coli) was more stable than gram-positive bacteria (S. aureus) against the antimicrobial effect of plasma-activated water and the longer time was necessary to completely deactivate it by PAW. While S. aureus was completely inactivated by PAW in the early exposure times. The effect of plasma-activated physiological serum on bacteria showed that plasma-activated physiological serum was more effective than PAW on gram-negative bacteria E. coli, but again its effect on gram-positive bacteria was greater than that of gram-negative bacteria. Plasma-activated water had a better half-life at 8 °C. However, it should be noted that before the use of cold PAW as a disinfectant, we must wait to its temperature reaches to room temperature, because low temperatures inactivated the PAW. This case for plasma-activated saline solution was inverse, so that saline solution stored at 37 °C had a better antimicrobial effect than the solution stored at 8 °C. As previously reported, PAW induces oxidative stress in bacteria. A study of the expression of oxyR, sodA, soxS and katG genes in PAW-treated E. coli showed that bacteria increase the expression of these genes to protect itself against active plasma-derived species, although the gene expression of katG (catalase enzyme encoder) was highest and more than double. This result was confirmed by measuring the concentration of catalase in E.coli treated. The results of the catalase concentration assay also showed that concentration of catalase was decreased in S. aureus after PAW treatment unlike E.coli.In general, it can be concluded that PAW and plasma-activated saline solution are a promising methods for controlling bacteria that their effects on bacteria depend on the species and even the bacterial strain. The antimicrobial effects of PAW has been attributed to the synergistic effects of acidic pH with reactive oxygen and nitrogen species. The concentration of these reactive species depends on the duration and voltage used for treated water by plasma. On the other hand, the antimicrobial effects of PAW is transient. One of the effective factors in maintaining the antimicrobial property of PAW is temperature, that low temperature will be slower the deactivation rate of PAW antimicrobial effects. However, it should be noted that storage at low temperatures temporarily deactivates the antimicrobial effect of PAW, which its temperature must reach to room temperature before used.

عنوان گونه گون

Assessing the antimicrobial properties of plasma activated water prepared by non-thermal air plasma on Escherichia coli and Staphylococcus aureus

عنصر شناسه اي

‏شکرزاده،

ساير عناصر نام

‏شیما

کد نقش

تهيه کننده

عنصر شناسه اي

‏زرینی،

عنصر شناسه اي

سیاهپوش،

عنصر شناسه اي

‏خلج کندری،

ساير عناصر نام

‏غلامرضا

ساير عناصر نام

‏ وحید

ساير عناصر نام

محمد

تاريخ

استاد راهنما

تاريخ

استاد راهنما

تاريخ

استاد مشاور

عنصر شناسه اي

تبریز