Thesis (M.Sc.) -Cairo University, 2024.

Bibliography: pages 72-86.

CF is a genetically recessive disease marked by frequent, chronic lung infections that impair lung function and cause early death. There are limited published data on microbiological surveillance of CF patients from Middle East including Egypt. Some bacterial species colonizing the airways have recently become resistant to routine antimicrobial therapy. This resistance is attributed mainly to the formation of biofilm matrices, offering physical and electrostatic protection from antimicrobials, host defences and other environmental stressors.

The present study was conducted to identify the bacteria colonizing the airways among a cohort of Egyptian children with CF. Additionally, antimicrobial susceptibility and biofilm formation capacity of the isolated bacteria were assessed.

In the current study, A total of 43 bacteria were isolated from 34 respiratory samples from Egyptian pediatric patients with CF sputum specimens, Identification of the isolates was done according to colony morphology and the conventional microbiological standard tests. Antibiotic susceptibility testing was performed using Kirby–Bauer disc diffusion method. Biofilm formation of isolated pathogens were performed by microtiter plate assay.

In the present study, the most frequently isolated microorganisms were S. aureus (51.2%) followed by P. aeruginosa (34.9%). Other less prevalent bacterial isolates included E. coli, Klebsiella spp., and Acinetobacter spp. (4.7% each). Regarding antibiotic susceptibility profile, S. aureus demonstrated the greatest resistance to penicillin and cefoxitin, with resistance rates of 95.5% and 81.8% respectively. followed with Erythromycin and tetracycline, with resistance rates of 68.2% and 45.5% respectively. Alarmingly, a high prevalence of MRSA was

observed among our tested isolates (81.8% of S. aureus isolates). Among P. aeruginosa isolates, cefepime and imipenem exhibited the highest resistance rates (26.7% each), followed by tobramycin (20%). All isolated pathogens produce biofilm with varying degrees. Among them 50% of S. aureus and 66.7% of P. aeruginosa were strong biofilm producers.

Our findings indicate a significantly higher prevalence of S. aureus chronic colonization among our CF patients. Meanwhile chronic colonization with P. aeruginosa was less prevalent. Unfortunately, there was a high prevalence of MRSA and biofilm formation among our isolated bacteria. Implementing strict preventive measures and infection control can help prevent MRSA-related exacerbations in these patients.

ﯾﻌﺪﱡ اﻟﺘﻠﯿﻒ اﻟﻜﯿﺴﻲ ﻣﺮﺿًﺎ وراﺛﯿًﺎ ﻣﺘﻨﺤﯿًﺎ ﯾﺘﺴﻢ ﺑﺎﻟﻌﺪوى اﻟﺮﺋﻮﯾﺔ اﻟﻤﺰﻣﻨﺔ واﻟﻤﺘﻜﺮرة اﻟﺘﻲ ﺗﺆﺛﺮ ﻋﻠﻰ وظﯿﻔﺔ اﻟﺮﺋﺔ وﺗﺴﺒﺐ اﻟﻮﻓﺎة اﻟﻤﺒﻜﺮة. ھﻨﺎك ﺑﯿﺎﻧﺎت ﻣﺤﺪودة ﻣﻨﺸﻮرة ﺣﻮل اﻟﻤﺮاﻗﺒﺔ اﻟﻤﯿﻜﺮوﺑﯿﻮﻟﻮﺟﯿﺔ ﻟﻤﺮﺿﻰ اﻟﺘﻠﯿﻒ اﻟﻜﯿﺴﻲ ﻣﻦ اﻟﺸﺮق اﻷوﺳﻂ ﺑﻤﺎ ﻓﻲ ذﻟﻚ ﻣﺼﺮ. ﺑﻌﺾ أﻧﻮاع اﻟﺒﻜﺘﯿﺮﯾﺎ اﻟﺘﻲ ﺗﺴﺘﻌﻤﺮ
اﻟﺠﮭﺎز اﻟﺘﻨﻔﺴﻲ أﺻﺒﺤﺖ ﻣﺆﺧﺮًا ﻣﻘﺎوﻣﺔ ﻟﻠﻌﻼج ﺑﺎﻟﻤﻀﺎدات اﻟﺤﯿﻮﯾﺔ اﻟﺮوﺗﯿﻨﯿﺔ. ﺗﻌﺰى ھﺬه اﻟﻤﻘﺎوﻣﺔ
ﺑﺸﻜﻞ أﺳﺎﺳﻲ إﻟﻰ ﺗﻜﻮﯾﻦ ﻣﺼﻔﻮﻓﺎت اﻷﻏﺸﯿﺔ اﻟﺤﯿﻮﯾﺔ، ﻣﻤﺎ ﯾﻮﻓﺮ ﺣﻤﺎﯾﺔ ﻓﯿﺰﯾﺎﺋﯿﺔ وﻛﮭﺮﺑﺎﺋﯿﺔ ﻣﻦ اﻟﻤﻀﺎدات اﻟﺤﯿﻮﯾﺔ واﻟﺪﻓﺎﻋﺎت اﻟﻤﻀﯿﻔﺔ واﻟﻌﻮاﻣﻞ اﻟﺒﯿﺌﯿﺔ اﻷﺧﺮى.
ﺗﻢ اﺟﺮاء اﻟﺪراﺳﺔ اﻟﺤﺎﻟﯿﺔ ﻟﺘﺤﺪﯾﺪ اﻟﺒﻜﺘﯿﺮﯾﺎ اﻟﺘﻲ ﺗﺴﺘﻌﻤﺮ اﻟﺠﮭﺎز اﻟﺘﻨﻔﺴﻲ ﺑﯿﻦ ﻣﺠﻤﻮﻋﺔ ﻣﻦ
اﻷطﻔﺎل اﻟﻤﺼﺮﯾﯿﻦ اﻟﻤﺼﺎﺑﯿﻦ ﺑﺎﻟﺘﻠﯿﻒ اﻟﻜﯿﺴﻲ. ﺑﺎﻹﺿﺎﻓﺔ إﻟﻰ ذﻟﻚ، ﺗﻢ ﺗﻘﯿﯿﻢ ﺣﺴﺎﺳﯿﺔ اﻟﻤﻀﺎدات اﻟﺤﯿﻮﯾﺔ وﻗﺪرة ﺗﻜﻮﯾﻦ اﻷﻏﺸﯿﺔ اﻟﺤﯿﻮﯾﺔ ﻟﻠﺒﻜﺘﯿﺮﯾﺎ اﻟﻤﻌﺰوﻟﺔ.
ﻓﻲ اﻟﺪراﺳﺔ اﻟﺤﺎﻟﯿﺔ، ﺗﻢ ﻋﺰل ﻣﺠﻤﻮﻋﮫ 43 ﺑﻜﺘﯿﺮﯾﺎ ﻣﻦ 34 ﻋﯿﻨﺔ ﺗﻨﻔﺴﯿﺔ ﻣﻦ ﻣﺮﺿﻰ اﻷطﻔﺎل اﻟﻤﺼﺮﯾﯿﻦ اﻟﻤﺼﺎﺑﯿﻦ ﺑﺎﻟﺘﻠﯿﻒ اﻟﻜﯿﺴﻲ. ﺗﻢ ﺗﺤﺪﯾﺪ اﻟﻌﺰﻻت وﻓﻘًﺎ ﻟﺸﻜﻞ اﻟﺒﻜﺘﺮﯾﺎ اﻟﻤﺴﺘﻌﻤﺮة واﻻﺧﺘﺒﺎرات اﻟﻘﯿﺎﺳﯿﺔ اﻟﻤﯿﻜﺮوﺑﯿﻮﻟﻮﺟﯿﺔ اﻟﺘﻘﻠﯿﺪﯾﺔ. ﺗﻢ إﺟﺮاء اﺧﺘﺒﺎر ﺣﺴﺎﺳﯿﺔ اﻟﻤﻀﺎدات اﻟﺤﯿﻮﯾﺔ ﺑﺎﺳﺘﺨﺪام طﺮﯾﻘﺔ اﻻﻧﺘﺸﺎر ﺑﺎﺳﺘﺨﺪام اﻟﻘﺮص (Kirby-Bauer) وﺗﻢ إﺟﺮاء ﺗﻜﻮﯾﻦ اﻷﻏﺸﯿﺔ اﻟﺤﯿﻮﯾﺔ ﻣﻦ ﻣﺴﺒﺒﺎت اﻷﻣﺮاض اﻟﻤﻌﺰوﻟﺔ ﺑﺎﺳﺘﺨﺪام طﺮﯾﻘﺔ طﺒﻖ زراﻋﺔ اﻷﻧﺴﺠﺔ اﻟﻤﯿﻜﺮوﺗﯿﺘﺮ.
ﻓﻲ اﻟﺪراﺳﺔ اﻟﺤﺎﻟﯿﺔ، ﻛﺎﻧﺖ اﻟﻜﺎﺋﻨﺎت اﻟﺤﯿﺔ اﻟﺪﻗﯿﻘﺔ اﻟﻤﻌﺰوﻟﺔ اﻷﻛﺜﺮ ﺷﯿﻮﻋًﺎ ھﻲ اﻟﻤﻜﻮرات اﻟﻌﻨﻘﻮدﯾﺔ
اﻟﺬھﺒﯿﺔaureus) (S. (51.2%) ﺗﻠﯿﮭﺎ اﻟ ﱠﺰاﺋِﻔَﺔُ اﻟﺰِّﻧْﺠﺎرِﯾﱠﺔ aeruginosa) (P. (34.9%) وﺷﻤﻠﺖ
اﻟﻌﺰﻻت اﻟﺒﻜﺘﯿﺮﯾﺔ اﻷﻗﻞ اﻧﺘﺸﺎرًا اﻹﺷﺮﯾﻜﯿﺔ اﻟﻘﻮﻟﻮﻧﯿﺔ coli) (E. واﻟﻜﻠﯿﺒﺴﯿﻼspp.) (Klebsiella ،
واﻟﻤﻜﻮرات اﻟﺮاﻛﺪةapp.) (Acinetobacter %4.7) ﻟﻜﻞ ﻣﻨﮭﺎ.( ﻓﯿﻤﺎ ﯾﺘﻌﻠﻖ ﺑﻤﻠﻒ ﺣﺴﺎﺳﯿﺔ
اﻟﻤﻀﺎدات اﻟﺤﯿﻮﯾﺔ، أظﮭﺮت اﻟﻤﻜﻮرات اﻟﻌﻨﻘﻮدﯾﺔ اﻟﺬھﺒﯿﺔ أﻛﺒﺮ ﻣﻘﺎوﻣﺔ ﻟﻠﺒﻨﺴﻠﯿﻦ واﻟﺴﯿﻔﻮﻛﺴﯿﺘﯿﻦ، ﻣﻊ ﻣﻌﺪﻻت ﻣﻘﺎوﻣﺔ ﺑﻠﻐﺖ %95.5 و%81.8 ﻋﻠﻰ اﻟﺘﻮاﻟﻲ. ﺗﻠﺘﮭﺎ اﻹرﯾﺜﺮوﻣﺎﯾﺴﯿﻦ واﻟﺘﺘﺮاﺳﯿﻜﻠﯿﻦ، ﺑﻤﻌﺪﻻت
ﻣﻘﺎوﻣﺔ ﺑﻠﻐﺖ %68.2 و%45.5 ﻋﻠﻰ اﻟﺘﻮاﻟﻲ. وﻣﻦ اﻟﻤﻘﻠﻖ ﻣﻼﺣﻈﺔ وﺟﻮد ﻧﺴﺒﺔ ﻋﺎﻟﯿﺔ ﻣﻦ اﻟﻤﻜﻮرات اﻟﻌﻨﻘﻮدﯾﺔ اﻟﺬھﺒﯿﺔ اﻟﻤﻘﺎوﻣﺔ ﻟﻠﻤﯿﺜﯿﺴﯿﻠﯿﻦ(MRSA) ﺑﯿﻦ اﻟﻌﺰﻻت اﻟﺘﻲ ﺗﻢ اﺧﺘﺒﺎرھﺎ (%81.8) .
ﻣﻦ ﺑﯿﻦ ﻋﺰﻻت اﻟ ﱠﺰاﺋَِﻔﺔُ اﻟِّﺰْﻧﺠﺎرِﯾﱠﺔ، أظﮭﺮ اﻟﺴﯿﻔﯿﺒﯿﻢ واﻹﯾﻤﯿﺒﯿﻨﯿﻢ أﻋﻠﻰ ﻣﻌﺪﻻت ﻣﻘﺎوﻣﺔ %26.7) ﻟﻜﻞ ﻣﻨﮭﻤﺎ(، وﺗﻼھﻤﺎ اﻟﺘﻮﺑﺮاﻣﯿﺴﯿﻦ .(%20) أﻧﺘﺠﺖ ﺟﻤﯿﻊ اﻟﻌﺰﻻت اﻟﺒﻜﺘﯿﺮﯾﺔ أﻏﺸﯿﺔ ﺣﯿﻮﯾﺔ ﺑﺪرﺟﺎت ﻣﺘﻔﺎوﺗﺔ. ﻣﻦ ﺑﯿﻨﮭﺎ، ﻛﺎن %50 ﻣﻦ اﻟﻤﻜﻮرات اﻟﻌﻨﻘﻮدﯾﺔ اﻟﺬھﺒﯿﺔ aureus) (S. و%66.7 ﻣﻦ ﻋﺰﻻت اﻟ ﱠﺰاﺋَِﻔﺔُ اﻟِّﺰْﻧﺠﺎرِﯾﱠﺔ aeruginosa) (P. ﻣﻦ ﻣﻨﺘﺠﻲ اﻷﻏﺸﯿﺔ اﻟﺤﯿﻮﯾﺔ اﻟﻘﻮﯾﺔ.
ﺗﺸﯿﺮ ﻧﺘﺎﺋﺠﻨﺎ إﻟﻰ ارﺗﻔﺎع ﻛﺒﯿﺮ ﻓﻲ اﻧﺘﺸﺎر اﻻﺳﺘﻌﻤﺎر اﻟﻤﺰﻣﻦ ﻟﻠﻤﻜﻮرات اﻟﻌﻨﻘﻮدﯾﺔ اﻟﺬھﺒﯿﺔ ﺑﯿﻦ ﻣﺮﺿﻰ اﻟﺘﻠﯿﻒ اﻟﻜﯿﺴﻲ ﻟﺪﯾﻨﺎ. ﻓﻲ ﺣﯿﻦ أن اﻟﺘﻜﺎﺛﺮ اﻟﻤﺰﻣﻦ ﻟﻠﺰاﺋﻔﺔ اﻟِّﺰْﻧﺠﺎرِﯾﱠﺔ ﻛﺎن أﻗﻞ اﻧﺘﺸﺎرًا. ﻟﺴﻮء اﻟﺤﻆ، ﻛﺎن ھﻨﺎك اﻧﺘﺸﺎر ﻣﺮﺗﻔﻊ ﻟـﻠﻤﻜﻮرات اﻟﻌﻨﻘﻮدﯾﺔ اﻟﺬھﺒﯿﺔ اﻟﻤﻘﺎوﻣﺔ ﻟﻠﻤﯿﺜﯿﺴﯿﻠﯿﻦ (MRSA) وﺗﻜﻮﯾﻦ اﻷﻏﺸﯿﺔ اﻟﺤﯿﻮﯾﺔ ﺑﯿﻦ اﻟﺒﻜﺘﯿﺮﯾﺎ اﻟﻤﻌﺰوﻟﺔ ﻟﺪﯾﻨﺎ. ﯾﻤﻜﻦ أن ﯾﺴﺎﻋﺪ ﺗﻄﺒﯿﻖ ﺗﺪاﺑﯿﺮ وﻗﺎﺋﯿﺔ ﺻﺎرﻣﺔ وﻣﺮاﻗﺒﺔ
اﻟﻌﺪوى ﻓﻲ ﻣﻨﻊ ﺗﻔﺎﻗﻢ اﻟﺤﺎﻻت اﻟﻤﺮﺗﺒﻄﺔ ﺑﺎﻟﻤﻜﻮرات اﻟﻌﻨﻘﻮدﯾﺔ اﻟﺬھﺒﯿﺔ اﻟﻤﻘﺎوﻣﺔ ﻟﻠﻤﯿﺜﯿﺴﯿﻠﯿﻦ (MRSA) ﻟﺪى ھﺆﻻء اﻟﻤﺮﺿﻰ.

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Text in English and abstract in Arabic & English.