Background and Objectives: Pseudomonas aeruginosa is a problematic opportunistic pathogen causing several types of nosocomial infections with a high resistance rate to antibiotics. Production of many virulence factors in P. aeruginosa is regulated by quorum sensing (QS), a cell-to-cell communication mechanism. In this study, we aimed to assess and compare the inhibitory effect of azithromycin (AZM) and EPI- PAβN (efflux pump inhibitor- Phenylalanine-Arginine Beta-Naphthylamide) on QS system and QS-dependent virulence factors in P. aeruginosa clinical isolates. Materials and Methods: A total of 50 P. aeruginosa isolates were obtained from different types of clinical specimens. Isolates were investigated for detection of QS system molecules by AHL cross-feeding bioassay and QS-dependent virulence factors; this was also confirmed by detection of QS genes (lasR, lasI, rhlR, and rhlI) using PCR assay. The inhibitory effect of sub-MIC AZM and EPI PAβN on these virulence factors was assessed. Results: All the P. aeruginosa, producing QS signals C4 HSL, failed to produce C4 HSL in the presence of sub-MIC AZM, In the presence of EPI PAβN (20 µg/ml) only 14 isolates were affected, there was a significant reduction in QS-dependent virulence factors production (protease, biofilm, rhamnolipid and pyocyanin) in the presence of either 20 µg/ml EPI or subMIC of AZM with the inhibitory effect of AZM was more observed than PAβN. Conclusion: Anti-QS agents like AZM and EPI (PAβN) are useful therapeutic options for P. aeruginosa due to its inhibitory effect on QS-dependent virulence factors production without selective pressure on bacteria growth, so resistance to these agents is less likely to develop.

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The emergence of resistance to methicillin resistant Staphylococcus aureus (S.aurus) (MRSA), followed by Vancomycin resistant S.aurus has turned the therapy of staphylococcal infections into a worldwide challenge. Three classes of vancomycinresistance have emerged that differ in vancomycin susceptibility; vancomycin resistant S.aureus (VRSA), Vancomycin intermediate S.aureus (VISA) and heterogenous vancomycin-Intermediate S.aureus (hVISA). Objectives: The present study aimed to detect S.aureus with reduced susceptibility to vancomycin in different types of clinical samples and their genomic characterizations. Methodology: The study was carried out on 250 S.aureus isolates from different types of clinical samples collected from patients admitted to various departments in the Alexandria University Hospitals, Egypt from May 2014 to April 2015. Results: We detected 22 S.aureus isolates with reduced sensitivity to vancomycin out of the 250 S.aureus test isolates by PAP-AUC and agar dilution methods. Three of them were VISA and 19 were hVISA; mainly isolated from pyogenic infections. Molecular typing of VISA and hVISA exhibited dominance of agr group Type I. Conclusion: Strict infection control measures and antibiotic policy should be adopted to control the problem of VISA and hVISA.

Background/objective Disinfection of a 3D-printed surgical guide is of utmost importance as it comes into contact with hard and soft tissue during implant placement so it poses a potential risk of pathogenic transmission. Methods used for disinfection in the surgical field should be reliable, practical, and safe for the instruments and the patients. The objectives of this study were to compare the antimicrobial potential of 100% Virgin Coconut Oil, 2% Glutaraldehyde, and 70% Ethyl Alcohol used to decontaminate 3D-printed surgical guides. Materials and methods Thirty identical surgical guides were printed and cut into two halves (N = 60). Both halves were then contaminated with a defined amount of human saliva samples (2 ml). The first half (n = 30) was sub-grouped into three study groups which were immersed in one of the three disinfectants for 20 min as follows; group VCO was immersed in 100% Virgin Coconut Oil, group GA was immersed in 2% Glutaraldehyde, and group EA was immersed in 70% Ethyl Alcohol. The second half (n* = 30) was sub-grouped into three control groups which were immersed in sterile distilled water as follows group VCO*, group GA*, and group EA*. The microbial count was expressed as colony-forming units per plate and the comparison of the antimicrobial potential of the three tested disinfectants between the three study and three control groups was done using the One-Way ANOVA test. Results The culture results of three study groups revealed no bacterial growth with the highest % of reduction in the mean microbial count of the oral microorganisms (about100%) and an uncountable bacterial growth was shown between the three control groups (more than 100 CFU/plate) representing the baseline of the oral microorganisms. Therefore; statistically significant differences were found between the three control and three study groups (P < .001). Conclusion The antimicrobial potential of Virgin Coconut Oil was comparable and equivalent to Glutaraldehyde and Ethyl Alcohol with a significant inhibitory action against oral pathogens.

Background and Objectives: Immunocompromised patients are considered a high-risk group to develop mycobacterial infections with either pulmonary and/or extra-pulmonary diseases. Low-cost and low-density (LCD) DNA-microarray is considered an easy and efficient method to detect typical and atypical Mycobacterial species. Materials and methods: Thirty immunocompromised patients were recruited to provide their clinical specimens (sputum, serum, urine and lymph node aspirate). Both Real-Time PCR and LCD-microarray techniques were performed and compared to the conventional methods of Ziehl-Neelsen (ZN) staining and Lowenstein Jensen (LJ) culturing. Results and conclusion: Mycobacterium tuberculosis complex (MTBC) was detected in all 30 clinical specimens (100% sensitivity) by Real-Time PCR and LCD-microarray. Additionally, co-infection with 4 atypical species belonging to mycobacteria other than tuberculosis (MOTT) was identified in 7 sputum specimens. These atypical mycobacterial species were presented as M. kansasii 10% (n=3), M. avium complex 6.6% (n=2), M. gordanae 3.3% (n=1) and M. peregnium 3.3% (n=1). This study documents the presence of certain species of atypical mycobacteria among immunocompromised patients in Egypt. To the best of our knowledge, this is the first detection of M. peregenium among clinical specimen in Egypt.