تحسين النشاط المضاد للميكروبات لجسيمات الفضة النانوية المقترنة مع اللينكومايسين

الباحث

آمنة منذر عبدالجبار

المشرف

نهاية نعمة حسين

الجامعة

الجامعة التكنولوجية

الكلية / القسم

قسم العلوم التطبيقية / التقنيات الأحيائية

الشهادة

ماجستير

السنة

2023

لغة الرسالة

انكليزي

الكلمات المفتاحية

Silver Nanoparticles ; Lincomycin ; Antimicrobial Activity ; Drug Conjugation

تم اختبار جزيئات الفضة النانوية المقترنة مع مضاد اللنكومايسين حيث اظهرت تأثيراً تأزرياً من خلال ملاحظة الزيادة الواضحة في قطر التثبيط, وكانت البكتريا الموجبة لصبغة غرام وفطر الكانديدا اكثر تأثراً من البكتريا السالبة لصبغة غرام تم استخدام تراكيز مختلفة من جزيئات الفضة النانوية )12.5 ٠، 25 ، 50 و 100( ميكروغرام / مل لتقييم التأثير على تكوين الغشاء الحيوي للعزلات الممرضة. أظهر نشاط مضاد حيوي بتركيزات عالية. شوهد أعلى تأثير في المبيضات Cnadida guilliermondii وكان أقل تأثير في Serratia marcescens أظهرت جزيئات الفضة النانوية المقترنة مع اللينكومايسين تأثيرًا تآزريًا ضد تكوين الأغشية الحيوية في Bacillus cereus و Proteus mirabilis و Candida guilliermondii ؟ في Serratia al marcescens يظهر أي تغيير في تكوين الغشاء الحيوي. تم تحديد النشاط المضاد للأكسدة لجزيئات dad) النانوية وجزيئات الفضة النانوية المقترنة مع اللينكومايسين بواسطة طريقة (12211-1،1 ،(Diphenyl-2-picryl-hydrazyl وأظهرت نتائج اختبارالكسح أن جزيئات الفضة النانوية تمتلك نشاطاً Shoe للأكسدة يزداد مع زيادة التركيزء وكذلك اظهرت جزيئات الفضة النانوية المقترنة مع اللينكومايسين نشاطًا مضادًا للأكسدة. كما تم استخدام quantitative real-time PCR (qRT-PCR) لتقييم التعبير الجيني لخمسة جينات مقاومة للمضادات الحيوية blaZ) ل ,B. cereus Sbla_,S. Warneri وروريوى 1ط P. mirabilis , marcescens, aac (6°) -Ib-cr-15 .كو CDR1I ل C. guilliermondii ( بعد المعالجة ب 100 ميكروغرام / مل من جزيئات الفضة النانوية أظهرت نتائج الجسيمات النانوية الفضية تأثير جسيمات الفضة النانوية في تثبيط التعبير الجيني لجميع العزلات P. ،B. cereus +C. guilliermondii ٠ S. warneri 5S. marcescens , mirabilis | على sll sill | | | | | | | | |

During the period from November to February of 2022, one hundred isolates were collected from burns and wounds, including 15 Isolates of Staphylococcus warneri, 23 isolates of Bacillus cereus, 32 isolates of Proteus mirabilis, 21 isolates of Serratia marcescens, and 9 isolates of Candida guilliermondii, samples were obtained from patients at medical city/ Education Laboratories in Baghdad/ Iraq. The isolates were diagnosed through traditional methods, and the microbial species were confirmed using the Vitek2 technique. Silver nanoparticles were synthesized by using the chemical reduction method and then conjugated with a lincomycin antibiotic. Silver nanoparticles and their conjugates were characterized by several techniques, including UV/vis spectrophotometer, where the highest peak of the UV spectrum appeared at 428nm for AgNPs and 440nm for AgNPsـlincomycin conjugation, Fourier Transform ـ Infrared spectroscopy (FTIR), Xـray diffraction (XRD), determined that the silver nanoparticles size was ~32.28nm and silver nanoparticles-lincomycin conjugation was ~38.253nm after applying the Scherrer equation, Dynamic light scattering (DLS) analysis were poly- dispersed with an average mean size were 35.45nm for silver nanoparticles and 40nm with monodispersed for silver nanoparticles-lincomycin, Where zeta potential results indicate that AgNPs and AgNPs-lincomycin were moderate stability with a negative charge. Field Emission-Scanning Electron Microscopes (FE-SEM) results showed the particle shape of silver nanoparticles was spherical with size ranging between (31.26 to 67.3) nm and silver nanoparticles-lincomycin showed different shapes for nanoparticles staked together. Transmission Electrons Microscopy (TEM) results exhibited that the majority of NPs it has a spherical form with ±26.53nm average mean size for silver nanoparticles and ±30.42nm for silver nanoparticles- lincomycin. The Minimum Bactericidal Concentration and the Minimum Inhibitory Concentration of silver nanoparticles and silver nanoparticles-lincomycin were also determined. The results showed that the MIC of silver nanoparticles was (25 μg/ml) for Staphylococcus warneri and Candida guilliermondii, (50 μg/ml) for Bacillus cereus and Proteus mirabilis, (100 μg/ml) for Serratia marcescens; While the MIC of AgNPs-lincomycin was (12.5 μg/ml) for Staphylococcus warneri, Bacillus cereus and Candida guilliermondii, (25 μg/ml) for Proteus mirabilis, and (50 μg/ml) for Serratia marcescens. Whereas, the minimum bactericidal concentration (MBC) was higher than MIC. The results recorded that the MBC of silver nanoparticles was (50 μg/ml) for Staphylococcus warneri and Candida guilliermondii, (100 μg/ml) for Bacillus cereus and Proteus mirabilis, While the results recorded that the MBC of AgNPs-lincomycin was (25 μg/ml) for Staphylococcus warneri, Bacillus cereus and Candida guilliermondii, (50 μg/ml) for Proteus mirabilis. While Serratia marcescens was highly resistant, MBC didn’t appear. Silver nitrate inhibited the growth of isolates at 5 millimolar (mM) concentrations. Silver nanoparticles inhibited the growth of all isolates, at concentrations (12.5, 25, 50, and 100) μg/ml, except Serratia marcescens was inhibited at concentrations (100 and 50) μg/ml. The results detected that silver nanoparticles had more antimicrobial efficiency against microbial growth than silver nitrate. The synergistic activity of silver nanoparticlesـlincomycin mixture, on the pathogenic growth of microbial isolates, demonstrated that the inhibition zone diameters were increased at 100μg/ml concentration. An antibiotic susceptibility testing was performed on all isolates, and it was observed that some isolates showed resistance to lincomycin. Different concentrations of silver nanoparticles (12.5, 25, 50 and 100) μg/ml were used to evaluate the effect on biofilm formation of pathogenic isolates. It showed an antibiofilm activity at high concentrations. The highest effect was seen in the Candida guilliermondii and the lowest effect was seen in the Serratia marcescens. Silver nanoparticles-lincomycin showed a synergistic effect against biofilm formation in all isolates, except Serratia marcescens no change in its biofilm composition was shown. Antioxidant activity for silver nanoparticles and silver nanoparticlesـlincomycin was determined by the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) method, and the resultes demonstrated that silver nanoparticles have antioxidant activity increased with increasing the concentrations of AgNPs, and AgNPsـlincomycin was showed antioxidant activity. In the present study, quantitative real-time PCR (qRT-PCR) was used to evaluate the gene expression of five antibiotic resistance genes (blaZ for S. warneri, bla for B. cereus, blaCTXـMـ15 for P. mirabilis, aac(6 ́)ـIbـcr for S. marcescens, and CDR1 for C. guilliermondii) after treated with 100 μg/ml silver nanoparticles results showed the effect of silver nanoparticles was clear on the inhibition of gene expression for all isolates, C. guilliermondii, B. cereus, P. mirabilis, S. marcescens and S. warneri respectively.

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