Omneya Helmy

Eradication of Helicobacter pylori, the class 1 carcinogen, faces several obstacles, which demand alternative options to conventional drug development methods. Alanine racemase (Alr) was proposed as H. pylori drug target, inhibited by propanoic acid (PA), in a previous in silico study. We investigated the possible treatment of H. pylori infection through Alr inhibition. A new model of H. pylori Alr was built, validated, and the binding of PA to the active site was modelled via molecular docking with a good docking score. PA minimum inhibitory concentration (MIC) against H. pylori ATCC 43504 and six H. pylori clinical isolates ranged from 312.5 to 416.7 ± 180 μg/ml and remained unchanged after 14 serial passages in increasing PA concentrations. The minimum bactericidal concentration of PA was 625 μg/ml. Selective Alr inhibition was confirmed by a significant PA MIC increase with increasing d-alanine concentrations. Similar PA MIC in other tested pathogens was recorded (312.5-625 μg/ml). PA lacked cytotoxicity in tested cell lines and efficiently eradicated H. pylori in a rat infection model. In conclusion, Alr is a promising broad-spectrum drug target, inhibited by PA without resistance development by repeated exposure for 14 serial passages.

Effective eradication therapy for is a worldwide demand. Aspartate α-decarboxylase (ADC) was reported as a drug target in . , in an study, with malonic acid (MA) as its inhibitor. We evaluated eradicating . infection through ADC inhibition and the possibility of resistance development. MA binding to ADC was modeled molecular docking. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of MA were determined against . ATCC 43504, and a clinical . isolate. To confirm selective ADC inhibition, we redetermined the MIC in the presence of products of the inhibited enzymatic pathway: β-alanine and pantothenate. HPLC was used to assay the enzymatic activity of . 6x-his tagged ADC in the presence of different MA concentrations. . strains were serially exposed to MA for 14 passages, and the MICs were determined. Cytotoxicity in different cell lines was tested. The efficiency of ADC inhibition in treating . infections was evaluated using a Sprague-Dawley (SD) rat infection model. MA spectrum of activity was determined in different pathogens. MA binds to . ADC active site with a good docking score. The MIC of MA against . ranged from 0.5 to 0.75 mg/mL with MBC of 1.5 mg/mL. Increasing β-alanine and pantothenate concentrations proportionally increased MA MIC. The 6x-his tagged ADC activity decreased by increasing MA concentration. No resistance to ADC inhibition was recorded after 14 passages; MA lacked cytotoxicity in all tested cell lines. ADC inhibition effectively eradicated . infection in SD rats. MA had MIC between 0.625 to 1.25 mg/mL against the tested bacterial pathogens. In conclusion, ADC is a promising target for effectively eradicating . infection that is not affected by resistance development, besides being of broad-spectrum presence in different pathogens. MA provides a lead molecule for the development of an anti-helicobacter ADC inhibitor. This provides hope for saving the lives of those at high risk of infection with the carcinogenic . .

() has been identified as a group-1 definite carcinogen. As of yet, there is no available vaccine for this microorganism. Our study aimed to identify antigenic peptides in using an in silico proteomic approach, and to evaluate their effectiveness as potential vaccine candidates. Four different peptide sequences were prioritized using the reverse vaccinology, namely, CagA, CagA, VacA, and SabA. Peptides emulsified with Freunde's adjuvant were used to immunize BALB/C mice. Subcutaneously immunized mice were challenged by oral administration of IgG, IgA, IL4, and IL17 were detected in mice sera. Histopathology of the dissected stomach of vaccinated and control mice were assessed using H&E stain. IgG was significantly higher in mice vaccinated with SabA. IL-4 was significantly increased in CagA, CagA, VacA, and SabA vaccinated mice compared to the adjuvant group. Additionally, histopathological examination of gastric tissue showed a protective effect in the vaccinated groups compared to adjuvant and PBS groups. Our findings indicate a promising effect of the tested epitopes, particularly the SabA antigen, to induce an immune response against .

This study investigated the effect of cefepime at sub-minimum inhibitory concentrations (sub-MICs) on in vitro biofilm formation (BF) by clinical isolates of . The effect of cefepime at sub-MIC levels (½-/ MIC) on in vitro BF by six clinical isolates of was phenotypically assessed following 24 and 48 h of challenge using the tissue culture plate (TCP) assay. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to observe the change in expression of three biofilm-related genes, namely, a protease-encoding gene (), fimbrial protein-encoding gene (), and alginate-encoding gene (), in a weak biofilm-producing strain of following 24 and 48 h of challenge with sub-MICs of cefepime. The BF morphology in response to cefepime was imaged using scanning electron microscopy (SEM). The TCP assay showed strain-, time-, and concentration-dependent changes in in vitro BF in following challenge with sub-MICs of cefepime, with a profound increase in strains with inherently no or weak biofilm-producing ability. RT-PCR revealed time-dependent upregulation in the expression of the investigated genes following challenge with ½ and ¼ MIC levels, as confirmed by SEM. Cefepime at sub-MICs could upregulate the expression of BF-related genes and enhance BF by clinical isolates.

Background: ) infection has been recognized as a significant threat for gastric cancer. However, studies that investigated the oncogenic factors and antimicrobial resistance of in Egyptian isolates with gastric cancer are rare. The current study aimed to examine: (1) The pattern of antimicrobial resistance of isolates of Egyptian gastric cancer patients, and (2) the prevalence of Cytotoxin-associated gene A (CagA).

Methods: Samples were collected from patients with gastric cancer. Isolation of was performed using Columbia blood agar supplemented with 10% horse blood, and selective supplement of for 3 to 5 days at 37 °C under microaerophilic condition. Isolates were identified by biochemical traits of oxidase, urease and catalase tests. Antimicrobial susceptibility of isolates was examined against five antimicrobial agents using disc diffusion method. After that, extraction of DNA and Polymerase Chain Reaction (PCR) were performed to amplify the target genes.

Results: Twelve samples were collected from six males and six females Egyptian patients with cancer with an age range from 22 to 65 years. These cases are scarce and samples were collected over a period of almost eleven months. All isolates were confirmed as positive through morphology and biochemical tests. The most effective antibiotic found was ciprofloxacin whereas all isolates showed resistance to metronidazole and erythromycin. The target CagA oncogene gene with expected product size was reported and seven (out of twelve) isolates (58%) were identified as CagA positive.

Conclusion: The current study is unique in two main aspects. First, it reported the pattern of antimicrobial susceptibility and prevalence of CagA gene in from Egyptian patients. Second, it exclusively recruited isolates from gastric cancer patients which were confirmed by clinical and laparoscopic examination. The moderately high prevalence of CagA gene in Egyptian cancer patients calls for more vigilance against that oncogene.