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بررسی و تشخیص آلودگی برج‎های خنک‌کننده پالایشگاه‌های کشور به باکتری Legionella pneumophila

نوع مقاله: مقاله پژوهشی

نویسندگان

گروه پژوهش میکروبیولوژی و بیوتکنولوژی، پژوهشکده محیط زیست و بیوتکنولوژی، پژوهشگاه صنعت نفت

چکیده

در صورت آلودگی آب برج‌های خنک‌کننده به باکتری Legionella pneumophila، به‌دلیل وجود شرایط مناسب در این سامانه‌ها، باکتری مذکور می‌تواند به سرعت تکثیر یابد. اگر آب آلوده به‌صورت قطرات معلق درآید، ذرات کوچک حاوی باکتری می‌تواند به سیستم تنفس افراد حساس وارد شده و در صورت عدم تشخیص به موقع، منجر به بروز بیماری لژیونر و مرگ شود. در این پژوهش آلودگی برج‌های خنک‌کننده پنج پالایشگاه کشور با استفاده از روش مبتنی بر کشت در چند نوبت مورد ارزیابی قرار گرفت. نتایج پژوهش، بیان‌گر آلودگی آب برج‌های خنک‌کننده سه پالایشگاه به این باکتری بود. بررسی‌های فصلی نشان داد که در اغلب موارد تعداد این باکتری در این سه پالایشگاه بیشتر از CFU/ml 100 بوده و در شرایط مناسب رشد، جمعیت این باکتری در یکی از پالایشگاه‌ها CFU/ml 800 و در دو پالایشگاه دیگر به CFU/ml 1000 (حد خطرناک) نیز می‌رسد. این امر نشان می‌دهد که در برخی از پالایشگاه‌ها روش‌های جاری تیمار آب و مدیریت آن کارآیی مناسبی ندارد. بنابراین لازم است فرآیند تمیزکاری و استفاده از زیست‌کش مناسب در آنها به‌کارگرفته شود و درخصوص اقدامات ضد میکروبی دقت بیشتری در این پالایشگاه‌ها اعمال گردد.
 

کلیدواژه‌ها


عنوان مقاله [English]

Investigation and Detection of Legionella Pneumophila in Iranian Oil Refineries’ Cooling Towers

نویسندگان [English]

  • Majid Soheili
  • Hassan Tirandaz
  • Rafat Kaveh-Ahangar
  • Abdalrasoul Heydarian
Microbiology and Biotechnology Research Group, Environmental and Biotechnology Division, Research Institute of Petroleum Industry, Tehran, Iran
چکیده [English]

Regarding the presence of appropriate conditions for the growth of Legionella pneumophila in cooling tower water, the population of this bacterium can rapidly increase in contaminated systems. When these waters are aerosolized, small respirable-sized droplets containing Legionella can reach the respiratory system of the susceptible person and cause Legionnaires’ disease. Legionnaires’ disease is a severe form of pneumonia that can be lethal if not detected in the early stage of contamination. In this research, the contamination of five Iranian oil refinery cooling towers with L. pneumophila was investigated by culture-dependent methods. The results showed that cooling towers in three refineries were contaminated by L. pneumophila. Seasonal investigation showed that in these cases bacterial count almost were more than 100 CFU/ml. In the two cases, in some seasons, bacterial counts were 1000 CFU/ml and in one another case it was 800 CFU/ml, which all were in the risk limit. The results showed that cooling tower water treatment and their management in some refineries were not sufficient and must be modified as soon as possible. Using suitable biocide and system cleaning along with extra attention on anti-microbial treatment should be applied.

کلیدواژه‌ها [English]

  • Legionella pneumophila
  • Legionnaires’ Disease
  • BCYE-α Agar
  • Cooling Tower
  • Iranian Refineries
  • Aerosol
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