Molecular study on expression of cytokines and Ý-peptides by epithelial cells in ocular infection and resistance of causative agents to gamma radiation and antimicrobial agents / Maha Ahmed Shafik Abdullah ; Supervised Mohammed Abdelhaleem Ramadan , Alaa Eldien Mahmoud Shawky Hosny , Zeinab Eldemerdash Mohamed Elbazza

Thesis (Ph.D.) - Cairo University - Faculty of Pharmacy - Department of Microbiology and Immunology

Infectious Conjunctivitis is a common eye infection that can be caused by different types of microbes which are either commensals or transferred from the environment. Topical antibiotics reduce the duration of the disease and prevent serious damage. One of the relevant problems related to the treatment of infections is the isolation of resistant bacterial isolates. In this study, 235 bacterial isolates were recovered from 150 patient{u2019}s conjunctiva during active bacterial conjunctivitis. The most predominant isolates were Staphylococcus species (50.6%) and gram-positive bacillus species (32.8%). Gram-negative rods represented 13.2% of the recovered isolates. The susceptibility pattern of all recovered bacterial isolates against different antibiotics was determined and the resistant bacterial isolates were detected in 95.3% of recovered bacterial isolates.After gamma irradiation of resistant isolates, the frequency of resistance at dose level 24.4 Gy increased against different selected antibiotic agents with different patterns.The prevalent increase in resistant to antibiotic agents compared to before irradiation was among Corynebacterium species and bacillus species followed by Staphylococcus species and gram negative rods. During infection, the conjunctival epithelium expresses inflammatory interleukins and antimicrobial peptides to defend as part of the innate immune response.The quantitative expression levels of the pro-inflammatory Interleukin-8 (IL8), Human beta defensin-2 (HBD2) and Human beta defensin-3 (HBD3) genes in bacterial conjunctivitis were detected by Reverse transcription- quantitative polymerase chain reaction (RT-qPCR).The relative gene expression showed that IL8, HBD2, and HBD3 were up-regulated in bacterial conjunctivitis as compared to healthy control (P<0.001)

Issued also as CD