Correlation of quorum sensing and virulence factors in Pseudomonas aeruginosa isolates in Egypt

  • Hamida M. Aboushleib Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
  • Hoda M. Omar Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
  • Rania Abozahra Faculty of Pharmacy, Damanhour University, Damanhour, Egypt
  • Amel Elsheredy Medical Research Institute, Alexandria University, Alexandria, Egypt
  • Kholoud Baraka Faculty of Pharmacy, Damanhour University, Damanhour, Egypt
Keywords: quorum sensing, virulence, Pseudomonas aeruginosa, genes, biofilm

Abstract

Introduction: Pseudomonas aeruginosa is one of the most virulent nosocomial pathogens worldwide. Quorum sensing (QS) regulates the production of pathogenic virulence factors and biofilm formation in P. aeruginosa. The four genes lasR, lasI, rhlR,and rhlI were found to regulate this QS system. In this study, we aimed to assess the correlation between these four genes and QS-dependent virulence factors and to detect the inhibitory effect of clove oil on QS.

Methodology: Fifty P. aeruginosa clinical isolates were collected. Susceptibility to different antibiotics was tested. Virulence factors including biofilm formation, pyocyanin production, and twitching motility were phenotypically detected. QS genes were amplified by polymerase chain reaction (PCR), and one strain subsequently underwent sequencing. The inhibitory effect of clove oil on virulence factors was also tested.

Results: A positive correlation was found between biofilm formation and the presence of lasR and rhlI genes. Twitching motility was positively correlated with the presence of lasR, lasI, and rhlI genes. On the other hand, no correlation was found between pyocyanin production and any of the studied genes. Only one isolate amplified all the tested QS gene primers, but it did not express any of the tested virulence factors phenotypically. Sequence analyses of this isolate showed that the four genes had point mutations.

Conclusions: Results emphasize the importance of QS in P. aeruginosa virulence; however, QS-deficient clinical isolates occur and are still capable of causing clinical infections in humans. Also, clove oil has an obvious inhibitory effect on QS, which should be clinically exploited.

Author Biographies

Hamida M. Aboushleib, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt

Professor in the Pharmaceutical Microbiology Department, Faculty of Pharmacy, Alexandria University.

Hoda M. Omar, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
Assistant Professor in the Pharmaceutical Microbiology Department, Faculty of Pharmacy, Alexandria University.
Rania Abozahra, Faculty of Pharmacy, Damanhour University, Damanhour, Egypt
Lecturer in the Pharmaceutical Microbiology Department, Faculty of Pharmacy, Damanhour University.
Amel Elsheredy, Medical Research Institute, Alexandria University, Alexandria, Egypt
Lecturer in Microbiology department, Medical Research Institute, Alexandria University
Kholoud Baraka, Faculty of Pharmacy, Damanhour University, Damanhour, Egypt
Assistant Lecturer in the Pharmaceutical Microbiology Department, Faculty of Pharmacy, Damanhour University.
Published
2015-10-29
How to Cite
1.
Aboushleib HM, Omar HM, Abozahra R, Elsheredy A, Baraka K (2015) Correlation of quorum sensing and virulence factors in Pseudomonas aeruginosa isolates in Egypt. J Infect Dev Ctries 9:1091-1099. doi: 10.3855/jidc.6492
Section
Original Articles