Luay Abu-Qatouseh

Synthesis of New Nitrofluoroquinolone Derivatives with Novel Anti-Microbial Properties against Metronidazole Resistant H. pylori

One of the major therapeutic approaches to preventing relapse and accelerating the healing of duodenal and gastric ulcers is the eradication of Helicobacter pylori. Due to the emergence of antibiotic resistance among clinical strains of H. pylori, alternative approaches using newly discovered antimicrobial agents in combination with the standard regimens for the treatment of H. pylori are increasingly needed. The purpose of the present study was to investigate the effect of newly synthesized 8-nitroflouroqunolone derivatives when used either alone or when combined with metronidazole against metronidazole-resistant H. pylori. Based on the standard antimicrobial susceptibility testing methods and checkerboard titration assay, all of the tested compounds showed interesting antimicrobial activity against 12 clinical strains of H. pylori, with the best in vitro effect for compound 3c. In addition, synergistic and additive activities of some of the tested compounds were observed when combined with metronidazole. Furthermore, among the tested nitroflouroquinolone derivatives, compound 3b showed significant urease inhibition activity with IC50 of 62.5 µg/mL. These results suggest that 8-nitroflouroquinolone derivatives may have a useful role in combination with anti-H. pylori drugs in the management of H. pylori-associated diseases.

Synthesis of 1,2,3-Triazolo[4,5-h]quinolone Derivatives with Novel Anti-Microbial Properties against Metronidazole Resistant Helicobacter pylori

Helicobacter pylori infection can lead to gastritis, peptic ulcer, and the development of mucosa associated lymphoid tissue (MALT) lymphoma. Treatment and eradication of H. pylori infection can prevent relapse and accelerate the healing of gastric and duodenal ulcers as well as regression of malignancy. Due to the increasing emergence of antibiotic resistance among clinical isolates of H. pylori, alternative approaches using newly discovered antimicrobial agents in combination with the standard antibiotic regimens for the treatment of H. pylori are of major importance. The purpose of the present study was to investigate the effect of newly synthesized 8-amino 7-substituted fluoroquinolone and their correspondent cyclized triazolo derivatives when either alone or combined with metronidazole against metronidazole-resistant H. pylori. Based on standard antimicrobial susceptibility testing methods and checkerboard titration assay, all of the tested compounds showed interesting antimicrobial activity against 12 clinical strains of H. pylori, with best in vitro effect for compounds 4b and 4c. Fractional inhibitory concentration (FIC) mean values showed synergistic pattern in all compounds of Group 5. In addition, additive activities of some of the tested compounds of Group 4 were observed when combined with metronidazole. In contrast, the tested compounds showed no significant urease inhibition activity. These results support the potential of new fluoroquinolone derivatives to be useful in combination with anti-H. pylori drugs in the management of H. pylori-associated diseases.

Detection of potential AcrAB-TolC multidrug efflux pump inhibitor in calyces extract of Hibiscus sabdariffa

Aim: The aim of this study is to investigate occurrence of potential efflux pump inhibitor (EPI) against AcrAB-TolC efflux pump in the methanol extract of H. sabdariffa. Materials and Methods: Calyces of H. sabdariffa were purchased from the local market in April 2014, methanol extract of H. sabdariffa was subjected to agar plate diffusion against Escherichia coli TG1 and its ∆acrB-∆tolC and thin layer chromatography (TLC) bioassay. The corresponding EPI fraction was eluted by methanol. The synergistic effect of antimicrobials and EPI fraction was measured by minimum inhibitory concentration (MIC) determination for E. coli and Erwinia amylovora strains, and the ability of EPI fraction to enhance EtBr accumulation was conducted. Results: E. coli TG1 was more sensitive to the methanol extracts of H. sabdariffa than E. coli ∆acrB-∆tolC, and inhibition zone corresponding to flavones on TLC bioassay plate has been formed which might be related to the fraction of potential EPI. The MIC values revealed that EPI fraction enhanced the activity of the used antimicrobials by 4 to 8 folds in E. coli TG1 and by 4 to 10 folds in E. amylovora 1189. Addition of EPI fraction in a dose-dependent manner increased the intercellular accumulation of Ethidium Bromide (EtBr) in the wild type stains of E. coli TG1 and E. amylovora 1189. Conclusion: EPI fraction behaves like a multidrug efflux pump inhibitor and further investigation should be conducted for determination of the chemical structure of EPI fraction.

Detection of High-Risk Human Papillomavirus Genotypes 16 and 18 in Head and Neck Squamous Cell Carcinomas in Jordan

Background: Recently, associations of the human papillomavirus (HPV) with head and neck cancer have become well established. Of particular concern, the severity and pathological outcomes of squamous cell carcinomas are remarkably affected by the genotypes of HPV present in such lesions. This study was conducted to investigate the occurrence of HPV genotypes, particularly high risk 16 and 18, among oral and laryngeal squamous cell carcinomas in Jordan. Methods: During the period of May 2015 to March 2016, we evaluated a total of 108 paraffin-embedded tissue samples, histologically confirmed as SCC, of both oral and laryngeal tumors for the presence of HPV DNA. DNA was extracted using a Zymogen commercial kit. HPV genotypes were detected by nested PCR using consensus primers followed by primer-specific PCR for HPV-16 and HPV-18 genotypes. The genotypes were confirmed by DNA sequencing methods. Results: Sixteen samples were positive for HPV DNA (14.8%) with higher rates in oral tumors compared to their laryngeal counterparts (20% and 6% respectively). The HPV-16 genotype predominated, being detected in 81.3% of the cases as a single infection and in 18.7% in combination with HPV-18. A significant association between the anatomical location and the HPV-16 genotype was observed (p < 0.05). In contrast, no significant associations could be established with tumor grade and gender or age. Conclusions: A relatively high rate of high-risk HPV genotypes, especially HPV 16, is evident in head and neck cancers SCCs in Jordan. Genotyping of HPV might be of considerable value for evaluation of progression.

Characterization of capsule expression of both MSSA/MRSA isolates from various body sites from colonization and infections cases

Background: Staphylococcus aureus is a major cause of nosocomial and community-acquired infections. Despite the predominance of two capsular polysaccharides, types 5 and 8, on the surface of clinical isolates, molecular and epidemiological variations have been reported among various geographical areas in addition to various clinical outcomes of S. aureus increasing the challenge for preventive and control measurements against staphylococcal infections and diseases. Materials and Methods: A total of 315 S. aureus isolates of various clinical conditions comprised both hospital and community-acquired infections between 2009 and 2011 in Amman and Gaza were studied. All S. aureus clinical isolates included in the present study have been investigated by PCR method to determine the distribution and diversity of capsule polysaccharide expression. Results: Most of the clinical isolates (90%) expressedeither capsular polysaccharide genotypes CP5 (37%) andCP8 (53%), whereas 10% were nontypeable by PCR. Significant predominance of CP8 geno type was reported in clinical isolates of S. aureus from infections in comparison to those which are commonly colonising various normal body sites.