This research was aimed to the purification and characterization of cytosine deaminase as a medically important enzyme from locally isolated Escherichia coli; then studying its cytotoxic anticancer effects against colon cancer cell line. Cytosine deaminase was subjected to three purification steps including precipitation with 90% ammonium sulfate saturation, ion exchange chromatography on DEAE-cellulose column, and gel filtration chromatography throughout Sephadex G-200 column. Specific activity of the purified enzyme was increased up to 9 U/mg with 12.85 folds of purification and 30.85% enzyme recovery. Characterization study of purified enzyme revealed that the molecular weight of cytosine deaminase produced by E. coli was about 48 KDa, the highest enzyme activity at pH 8.5, and is most stable at pH 7.5 - 9, the enzyme also showed a full activity at a range of temperatures between 45-60 0C. Enzyme activity was strongly inhibited in the presence of mercuric chloride and copper sulphate, when added individually at a constant concentration. However, calcium chloride, manganese chloride and ferric chloride caused a little increase in enzyme activity while sodium azide had no effect on enzyme activity. Upon cytotoxic effect study through micro-cultured tetrazolium assay (MTT) against Caco-2 cell line. Purified cytosine deaminase was found to inhibit the growth of Caco-2 cancer cell line with an IC50 of 242.5 ?g/ml in a comparison to an IC50 of 1864 ?g/ml for crude enzyme. Besides, the enzyme didn’t show significant effect on WRL normal cell line.
Some Factors determining the virulence of Escherichia coli ( E. coli ) isolates were studied ,of 25 isolates , 17(group A) uropathogenic E. coli ,6 (group B) infected gastrointestinal tract , 2 (group C) infected wound , beside these group we use the standard strain E. coli HB101 as control group. The twenty five isolates were tested for adherence capability to human buccal cavity epithelial cells by in vitro experiment . The results showed that all isolates have different adhesion capability with mean ranging from (14.35±11.39) to (33.80 ± 22.68) bacteria / epithelial cell It was noticed that isolates EU9, ES6, EW17 displayed high adhesive capability with mean value (33.80 ± 22.68), (32.60 ± 21.19), (29.90±22.50) bacteria /epithelial
... Show MoreThis study proposed to synthesize iron oxide by biological method nanoparticles. The E.coli is used to reduce Ferric chloride salt into iron particles. The formation of iron oxide nanoparticle was initially monitored by visual observation and then characterized with the help of various characterization techniques such as Uv-vis spectroscopy, (AFM) and (FTIR) analysis, which revealed that the biosynthesized iron oxide nanoparticles were spherical within size 27.7 nm. Optimization of iron oxide nanoparticle biosynthesis by E.coli was performed for parameters (temperature and pH) and the results revealed that temperature 37°C and pH 5 were the optimum conditions for iron oxide nanoparticales biosynthesis by E.coli.<
... Show MoreAs major nosocomial pathogens,
In this study, 20
Around fifty Escherichia coli isolates were isolated from sixty midstream urine specimens collected from patients visiting hospitals in Baghdad city. Approximately, 52% of all isolates were identified as extended spectrum beta lactamases (ESBL) producer. Results demonstrated that 92% of these isolates were sensitive to carbapenems. Only four β-lactamase coding genes were detected; blaTEM, blaPER, blaVIM and blaCTX-M-2. As a conclusion, this work revealed that local E. coli isolates harboured ESBL coding genes which may contribute in its pathogenicity.
Background: Invasive fungal infections have become more common during the past two decades. Candida species are the most common human fungal infections. Internal injuries characterize these infections because of virulence factors, such as gliotoxin, which is a fungal toxin that is thought to be antibacterial, antifungal, and antiviral.
Objectives: To test the ability of Candida species obtained from clinical sources to produce gliotoxin as a virulence factor and investigate its cytotoxicity effects against some selected cell lines.
Materials and Methods: One hundred and ten clinical isolates of Candida species were obtained from patients attendi
... Show MoreThis study aimed at isolating uropathogenic Escherichia coli from urinary tract infections (UTIs) of human and cattle to examine the molecular diversity and phylogenetic relationship of the isolates. A total of 100 urine samples were collected from UTIs of human and cattle. The isolates identification was done using routine diagnostic methods and confirmed by Vitek2. Antimicrobial susceptibility was tested against 10 antimicrobials. Random amplified polymorphic DNA (RAPD)-polymerase chain reaction (PCR) was applied to identify the genetic diversity among E. coli isolates from human and animal origin by using five different octamer primers. The gelJ software for the phylogenetic analysis created Dendrograms. Out of 50 human urine samples, E.
... Show MoreBackground:
Escherichia coli infections are becoming difficult treated because of extensive resistance to antibiotic among these organisms and manufacturing extended-spectrum beta lactamases enzymes (ESBLs) make them resistant to beta-lactam antibiotics. This study aims to offer a summary of the main horizontal transmission apparatuses between E. coli as well as Staphylococcus aureus and emergence resistance to antibiotics. Fifty of the E. coli and 50 of S. aureus isolates were examined to obtain minimum inhibitory concentration (MIC) results. These isolates were then tested by conventional polymerase chain-reaction for the existence or absenc
... Show MoreThis study was conducted in Wasit governorate for the period between February 2012 to February 2013 to determine the impact of Castor seed oil at different concentrations 100, 75, 50 and 25% in inhibition of the growth of E. coli isolated from 52 male and female patients (2-70 yrs) attending Al Zahra Hospital and Al Karama Hospital in Kut city. Oil was extracted from seeds of Castor had the ability to inhibit E. coli isolated from patients presented with recurrent urinary tract infections . Zone of inhibition accomplishing was 9.06 mm in diameter.HPLC analysis revealed that the content of α-linolenic in Castor seed oil (18.90 μg\ml) was higher than other fatty acids followed by oleic. Perhaps this is why it able to inhibit E. coli; whi
... Show MoreAdhesion (type 1 fimbriae) and host defense avoidance mechanisms (capsule or lipopolysaccharide) have been shown to be prevalent in Escherichia coli isolates associated with urinary tract infections. In this work, 50 uropathogenic Escherichia coli (UPEC) isolated from children with urinary tract infections were genotypically characterized by polymerase chain reaction (PCR) assay. We used two genes; fimH and kpsMTII, both of them previously identified in uropathogenic E.coli (UPEC) isolates. The PCR assay results identified fimH (90.0)% and kpsMTII (72.0)% isolates. In the present study, was also demonstrated that these genes may be included in both or one of them within a single isolate.