Biochemical and molecular study of staphyloxanthin extracted from clinical isolates of Staphylococcus aureus

Other Title(s)

دراسة كيموحيوية و جزيئية لصبغة الستافيلوزانثين المستخلصة من بكتريا العنقوديات الذهبية المعزولة من مصادر سريرية

Dissertant

al-Qazzaz, Iman Jihad Nafi

Thesis advisor

Melconian, Alice Krikor
Qandala, Nuha Juzif

Comitee Members

al-Ubaydi, Murawij Abd al-Sattar
Uthman, Sawsan H.
al-Qazzaz, Abd al-Karim Abd al-Razzaq Abd al-Wahhab

University

University of Baghdad

Faculty

College of Science

Department

Biotechnology Department

University Country

Iraq

Degree

Master

Degree Date

2014

English Abstract

Fourty three isolates ( 20.7%) characterized as Staphylococcus aureus , were isolated from 207 different clinical sources (blood , nose, , wound , urine , vaginal, ear and eye) in different percentages (30.23, 18.60, 16.28, 13.95, 15.15, 6.96 and 2.33) % respectively.

The results showed that blood samples were more accessible for contamination by this organism.

The antibiotic susceptibility test against 25 antibiotics revealed that all isolates were resistant to Amoxicillin/Clavulanic acid, Aztreonam, Carbenicillin, Ceftaxime, Cefotaxin, Cifixime, Nitrofluranton, Pencillin G, Pipracillin and Vancomycin in 100%, whereas they indicated variable resistance to the other antibiotics used.

While Imipenem and Trimethoprim were the most effective drugs used in the present study.

The results of staphyloxanthin production from S.aureus isolates on different culture media ( Milk agar medium ,Trypticase yeast medium , Trypticase soya medium ,Peanut seed medium and Sesame seed medium) was 44.1%, 37.2%, 37.2%.

30.2 % , 30.2 % respectively The Staphyloxanthin pigment was extracted using methanol and purified partially by organic solvents and Thin Layer Chromatography (TLC).

The results revealed three peaks with a highest peak at (450) nm.

The local isolate Staphylococcus aureus AE36 was selected in this study for its high productivity of Staphyloxanthin pigment (STX) .

The optimal conditions for pigment production by S.

aureus AE36 , were detected and was noticed that the milk agar medium revealed the highest production of pigment which was estimated 165.21unit/cell, at pH 8 for 72 hr at 370C.

Summary II No antibacterial activity of STX was detected against the bacteria used in this study (Staphylococcus epidermidis, Pseudomonas aeruginosa, Salmonella spp., Shigella spp., Escherichia coli, Klebsiella spp , Proteus spp.

Pseudomonas fluorescens , Pseudomonas putida , Staphylococcus aureus).

The wild-type (WT) S.

aureus AE36 pigmented bacterium was mutant using Ethyl Methane Sulphonate to inhibit the anti oxidant effect of the pigment has impaired neutrophil survival and its impact as a virulence factor , then compared with S.aureus AE38 the non pigmented bacterium and the parent S.

aureus AE36 , the results showed that the mutant wildtype S.

aureus AE36 was less pathogenic in a mouse subcutaneous abscess model and more susceptible to killing by neutrophil cell compared with the parent wild-type S.

aureus AE36.

Duplex real-time PCR assay represents a rapid and powerful method used for the detection of crtM gene (staphyloxanthin pigment production) and mecA gene (methicillin-resistance) in a single SYBR Green I Real- Time PCR assay.

Main Subjects

Biology

No. of Pages

140

Table of Contents

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Language

English

Data Type

Arab Theses

Record ID

BIM-601095