الفهرس 
coverOnly 14 pages are availabe for public view
 |  | from | 91 |  |  |
| | | from | 91 | | |
Abstract
Escherichia coli, which normally resides in the intestinal flora of warm-blooded animals, including humans, is ubiquitous in the environment and has been used as an indicator of faecal contamination to assess the safety and quality of food and water.
Escherichia coli is one of the commonest causes of bacteraemia in humans around the world, accounting for 15% - 40% of all significant bacteraemia isolates. Despite being a common and serious infection, there have been few recent studies describing the clinical features of E. coli bacteraemia, and few data are available on its population incidence.
Poultry food products are important sources of E. coli, because at the time of slaughter, faecal contamination from the intestines contaminated the carcass. As a result, poultry meat can be contaminated with faecal material or ingesta and with bacteria associated with these contaminants.
Escherichia coli biofilms are found to be the major causative agent of many intestinal infection. The most frequent causative agent for UTI has been recognized as E. coli and most of these isolates were recognized as resistant to antibiotics ampicillin, amoxicillin- clavulanic acid, norfloxacin, cefuroxime, ceftriaxone and co-trimoxazole. Diabetes, renal disease and use of intra uterine device are some of the risk factors associated with UTI which complicate the infection and increases the cost of treatment, morbidity and mortality.
It was discovered that the rapA gene altered the gene regulation of the biofilm that ensued lower expression of the 22 genes. Deletion of yhcQ gene which encodes the putative multidrug resistance pump decreased the biofilm penicillin G resistance in E. coli. Moreover the rapA mutation also reduced the extent of matrix coverage facilitating the penetration of penicillin.
There is an urgent need for the development of new therapeutic strategies to eradicate biofilm infections by E. coli.Only few studies have reported on the SA anti-biofilm effects on a matureand well-developed biofilm typical of microbial systems. Moreover, the SA anti-biofilm mechanism of action, thenature of its binding targets and cellular receptors remain unknown.
In view of the above, the present study was conducted to assess the role of aspirin as an overcoming strategy for biofilm formation in E. coli isolated from humans UTI samples and chicken.
To achieve that aim, total number of 435 samples collected from human urine samples and chicken with numbers 200 and 235 respectively from Alexandria governorate. At the microbiology lab the samples were cultivated, purified, bacterial isolates were identified. Antibiotic sensitivity tests, DNA extraction, biofilm formation and PCR were done according to standard protocols. The biofilms were treated with SA and antibiotic sensitivity tests were done after treatment with SA according to standard protocols.
Our study revealed incidence of E. coli of 158 and 110 with percentage of 79% and 46.8% in human urine and chicken samples respectively.
Our results revealed that most human E. coli samples were resistant to ampicillin and amoxicillin (63.33 and 60% respectively). In addition, 46.66 and 26.66% of human samples showed resistance to tetracycline and kanamycin respectively. Besides, resistance to cephalexin and erythromycin was encountered in 30% of cases.
Regarding E.coli isolated from chicken samples, ampicillin and amoxicillin resistance was detected in 63.88 and 61.11% of specimens respectively. Furthermore, neomycin and erythromycin resistance were detected in 44.44 and 41.66% of specimens respectively.
The PCR test for amplification of ndvB gene has demonstrated that the gene can be downregulated after aspirin treatment. In human samples, a significant increase in gene cut was observed (24.8 vs. 36.06 after treatment – p < 0.001). Regarding chicken, it showed the same response (27.04 vs. 35.35 after aspirin – p < 0.001).
Conclusion
Aspirin may be used as an adjuvant to antibiotics in the management of drug resistant E. coli infections. However, more studies conducting the same perspective should be conducted in the near future.