عبير عبد الرضا عباس الحسناوي

on human health. Several infections caused by this bacterium occur in both community acquired and hospital-acquired settings. Objective: This research aims to study the effect of magnesium oxide nanoparticles biosynthesized from Bacillus subtilis against multidrug-resistant (MDR) S. aureus isolated from various clinical infections. Methodology: A total of 230 specimens were collected from patients with different clinical infections referred to hospitals in Al-Najaf Province, Iraq, representing various age groups and both genders. Standard microbiological assays were used to identify S. aureus isolates, which were then subjected to antimicrobial susceptibility testing against 18 types of antibiotics using the disc diffusion method. Magnesium oxide nanoparticles (MgO NPs) were synthesized by mixing B. subtilis culture filtrate with magnesium nitrate solution. The color change from pale yellow to white indicated the formation of MgO NPs. Results: Out of the 230 specimens, 80 were identified as S. aureus isolates and tested for antimicrobial susceptibility. The results showed the highest resistance rate to Penicillin G (97.5%), while S. aureus showed no resistance to Vancomycin (0%). Among the 80 isolates, 45 (56.25%) were identified as multidrug-resistant (MDR S. aureus).The antibacterial activity of MgO nanoparticles at different concentrations (100, 200, 300, and 400 μg/ml) against S. aureus demonstrated that the inhibition zones increased proportionally with the concentration of MgO nanoparticles. Conclusion: This study concludes that higher concentrations of MgO nanoparticles biosynthesized by B. subtilis lead to an increased inhibition zone against MDR S. aureus, indicating a concentration dependent antibacterial effect. INTRODUCTION Staphylococcus aureus is a major human pathogen capable of adapting to diverse hosts and environmental conditions, causing a wide range of infections. Additionally, it is one of the leading causes of both hospital-acquired and community-acquired infections. It can cause infections of the bloodstream, skin and soft tissues, and lower respiratory tract; infections associated with medical instrumentation such as central-line associated bloodstream infections; as well as serious deep-seated infections such as osteomyelitis and endocarditis¹. S. aureus is among the most common bacterial pathogens in humans and is responsible for multiple infections, including infective endocarditis, skin and soft tissue infections (e.g., impetigo, folliculitis, furuncles, carbuncles, cellulitis, and scalded skin syndrome), septic arthritis, gastroenteritis, meningitis, urinary tract infections, pneumonia, and bloodstream infections².

The main objective of this manuscript was to prepare and evaluate the antimicrobial activity of AuNPs nanoparticles against the antibiotics resistant bacteria included Escherichia coli, pseudomonas aeruginosa and proteussp. Gold nanoparticles (AuNPs) was prepared by pulsed laser ablation in liquid (PLAL). The synthesis of nanoparticle were characterized by different techniques such as the diffraction of X-ray meam (X-RD), transmission electron microgram (TEM), atomic force microscopy (AFM), and absorption spectra of AuNPs (UV-Vis) spectra. The XRD displays Bragg’s diffraction peaks located at (110), (200) and (220) facts in the face-centered polycrystalline structure. Size and shape of nanoparticles were determined by TEM microgram with size ranging 50±5nm forming flower-shapes. Escherichia coli, Pseudomonas aeruginosa and Proteus sp. were isolated and identified from different clinical samples using traditional methods on bacteriological culture media. Antibacterial activity of AuNPs against multi-drug resistant bacteria were assayed qualitatively and quantitatively using two method; well diffusion and micro dilution, respectively. The antibacterial susceptibility of (Amoxicillin, Cefotaxime, Gentamicin and Ciproflouxacin) were analyzed on Muller Hinton agar (MHA) plate. The results of antibacterial susceptibility of bacterial isolates exhibited high resistance to the antibiotics that used in the current study. According to these findings gold nanoparticles revealed highest activity when using 100 μg/mL in well diffusion and the mean of inhibition zone was 26-37 mm for each Escherichia coli, Pseudomonas aeruginosa and proteussp. However, the minimum inhibitory concentration (MIC) values of gold nanoparticles recorded 75 and 73 μg/mL against Proteus sp. and P. aeruginosa, respectively. And 53 μg/mL was a lowest concentration of AuNPs for inhibiting E. coli. It is concluded that the AuNPs nanoparticles have in vitro

Abstract: The main objective of this study was to evaluate the bactericidal activity of Bi2O3nanospheres against the antimicrobial resistant isolates included Staphylococcus aureus, Escherichia coliandKlebsiella sp.Bismuth Oxide Nanospere particles was prepared by chemical reduction technique with (11-30)nm average diameter, the colloidal of Bi2O3nanospheres was characterized by using X-ray diffraction (XRD), TransmitionElectron Microscopy (TEM) and UV–Vis spectrophotometry. Three pathogenic strains of multi-drug resistant bacteria of each Staphylococcus aureus, Escherichia coliandKlebsiella sp.were isolated and identified from different clinical samples usingtraditional methods on bacteriological culture media. The antibacterial susceptibility of (Amoxicillin, Cefotaxime,Gentamicin, and Ciproflouxacin) were analyzed on Muller Hinton agar plate and the activity of Bi2O3nanospheres was assayed using well diffusion method against tested bacteria. The results of antibacterial susceptibility of bacterial isolates exhibited high resistance to the antibiotics that used in the current study. According to these findings thecolloidalof Bi2O3nanospheres revealed highest activity when using 100 μg/ml and the mean of inhibition zone was 18-22 mm for each S. aureus, E. coliandKlebsiella sp. However, the study showed slight effects (meanof inhibition zones ≤ 13 mm) when used50μg/ml of Bi2O3nanospheres. In same way, the E. coliandKlebsiellasp were more susceptible (mean of inhibition zones;15-12mm) for 150μg/mlofBi2O3nanospheres, than S. aureus. It is concluded that theBi2O3nanosphereshave insitu effectiveness an displayed a good antibacterial action against the tested bacterial isolates.

Currently, uncontrolled and repeated use of antibiotic may be cause evolution of microbial resistance among pathogenic agents. Consequently, the use of new artificial and natural antimicrobial compounds is inevitable. In this study was designed to evaluated the antibacterial effectiveness of aqueous and methanol extract of pomegranate peels against six types of bacteria (Staphylococcus aureus, Escherichia coli and Pseudomonas aeroginosa, Klebsiella pneumonia, Streptococcus pyogenes, Proteus mirabilis). The antibacterial effectiveness of pomegranate peel extract was studied and compared with Tetracycline which used as Positive Control.The various Concentrations (25, 50,75, 100mg/ml) of the methanol and aqueous peel extracts were tested and Evaluations were done by using agar well diffusion technique for the inhibition zone determination. The results obtained were encouraging as the methanol extract showed greater zones of inhibition against the various bacteria tested in comparison with the aqueous extract. The greatest zone of inhibition induced by the action of pomegranate peel extracts was obtained from Staphylococcus aureus 22.33 mm at (100) mg/ml in methanol extract while the smallest zone of inhibition was obtained from pseudomonas aerognosa 5.5 mm at (25) mg/ ml in aqueous extract. The antibacterial effect of pomegranate peels extracts was more effectiveness against Gram-positive bacteria than Gram-negative bacteria

to 1st July . liver samples were collected for bacterial isolation and identification, with histopathological examination. Pathogenic agents were isolated and identified by using culture media (Nutrient agar, Salmonella Shigella agar, MacConkey agar , pseudomonas agar and EMB agar), biochemical tests and Api20 test for confirmation.Result of this study showed differences between the bacterial isolates in first period from bacterial isolates in second period. The results of bacterial isolates in the first period were (E.coli 23.5%, Enterobacter 21.6% and Aeromonashydrophila 7.8% for the months January, February and March ) , while results of the bacterial isolates in the second period were (E. coli 35.3%, klebseliaoxytoca 15.7%, Salmonella Spp 3.9%, Pseudomonas aeruginosa 7.8% , K.pneumonia 9.8%). Histopathological results show Vaculation, necrosis and nuclear condensation were observed in hepatocytes of effected livers. In conclusion, According to the results obtained in this study, we investigated that , the time period from April up to July pathogenic agent ratio was more than pathogens agent ratio that was isolated in the months of January, February and March. Keywords: common carp, Bacterial disease ,Aeromonashydrophila, liver

Diarrhea is one of the most common infectious gastroenteritis diseases in the children under two years old. The present study included 100 diarrhea samples from children patients under two years attending to Al-zahraa teaching hospital for Maternity and Children in Najaf during the period from September2013 to February 2014. From these 100 samples : 6o samples gave positive stool culture (causes by bacteria ) , and 40 samples were negative results(causes by other causative agent such parasitic agent , viral agent ,food tolerance and reaction to medicines). Out of 6o samples :30 isolates of E.coli causes diarrhea and 30other bacteria isolates causes diarrhea. The study dealt with Identification of E.coli from diarrheatic patients by using automated VITEK-2 compact system using Gram Negative-Identification (GN-ID) cards and detect some virulence factors of the E.coli such as : hemolysin , proteases, capsule, bioflim production , adhesion. The results explained that all isolates of E.coli have polysaccharide capsules ,it able to produce hemolysin was 51.6% , also it able to produce proteases enzymes was 35.4% ,E.coli able to bioflim formation was 74.2% and E. coli have able to adhere with epithelial cell was 80.6%.

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