جدا شده از oxa23 شناسايي ژنوتيپ ايزوله هاي اسينتوباكتر بوماني مقاوم به كارباپنم حامل ژن نمونه هاي باليني در بيمارستان هاي منتخب شهر تهران 1391-92

Assessment the Genotypes of Carbapenem Resistant Acinetobacter baumannii Isolates Carrying oxa23 Recovered from Clinical Specimens in Selected Hospitals of Tehran

زﻣﯿﻨﻪ و ﻫﺪف: زﻣﺎن ﮐﻮﺗﺎﻫﯽ ﭘﺲ از ﻣﻌﺮﻓﯽ و ﻣﺼﺮف ﮐﺎرﺑﺎﭘﻨﻢ ﻫﺎ ﺑﻮﯾﮋه اﯾﻤﯽ ﭘﻨﻢ، ﻧﺨﺴﺘﯿﻦ ﺳﻮﯾﻪ اﺳﯿﻨﺘﻮﺑﺎﮐﺘﺮ ﺑﻮﻣﺎﻧﯽ ﻣﻘﺎوم ﺑﻪ اﯾﻤﯽ ﭘﻨﻢ، ﭘﺪﯾﺪار ﺷﺪ. ﻣﻘﺎوﻣﺖ ﺑﻪ اﯾﻤﯽ ﭘﻨﻢ در اﯾﻦ ﺳﻮﯾﻪ را ﺑﻪ ﺣﻀﻮر ژن oxa23 ﺑﻪ ﻋﻨﻮان ﺷﺎﯾﻊ ﺗـﺮﯾﻦ ژن ﮐـﺪ ﮐﻨﻨـﺪه ﻣﻘﺎوﻣـﺖ ﺑـﻪ ﮐﺎرﺑـﺎﭘﻨﻢ در اﺳﯿﻨﺘﻮﺑﺎﮐﺘﺮ ﺑﻮﻣﺎﻧﯽ ﻧﺴﺒﺖ دادﻧﺪ. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ وﻓﻮر ژن oxa23 در اﯾﺰوﻟﻪ ﻫﺎي ﺑﻮﻣﯽ اﺳﯿﻨﺘﻮﺑﺎﮐﺘﺮ ﺑﻮﻣﺎﻧﯽ، ﺷﻨﺎﺳﺎﯾﯽ ژﻧﻮﺗﯿﭗ اﯾﺰوﻟﻪ ﻫـﺎي در ﺣﺎل ﮔﺮدش ﯾﺎ اﻧﺪﻣﯿﮏ در ﺑﯿﻤﺎرﺳﺘﺎن ﻫﺎ اﻫﻤﯿﺖ ﺑﺴﺰاﯾﯽ دارد. ﻫﺪف از اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺷﻨﺎﺳﺎﯾﯽ ژﻧﻮﺗﯿﭗ اﯾﺰوﻟـﻪ ﻫـﺎي اﺳـﯿﻨﺘﻮﺑﺎﮐﺘﺮ ﺑﻮﻣـﺎﻧﯽ ﻣﻘﺎوم ﺑﻪ ﮐﺎرﺑﺎﭘﻨﻢ ﺣﺎﻣﻞ ژن oxa23 ﺟﺪا ﺷﺪه از ﻧﻤﻮﻧﻪ ﻫﺎي ﺑﺎﻟﯿﻨﯽ در ﺑﯿﻤﺎرﺳﺘﺎن ﻫﺎي ﻣﻨﺘﺨﺐ ﺷﻬﺮ ﺗﻬﺮان ﺑﻮد. ﻣﻮاد و روش ﻫﺎ: ﭘﺲ از ﺟﻤﻊ آوري و ﺷﻨﺎﺳﺎﯾﯽ ﻣﻮﻟﮑﻮﻟﯽ 92 اﯾﺰوﻟﻪ اﺳﯿﻨﺘﻮﺑﺎﮐﺘﺮ ﺑﻮﻣـﺎﻧﯽ، آزﻣـﺎﯾﺶ ﺣﺴﺎﺳـﯿﺖ آﻧﺘـﯽ ﺑﯿـﻮﺗﯿﮑﯽ ﺑـﻪ روش دﯾﺴﮏ دﯾﻔﯿﻮژن اﻧﺠﺎم ﺷﺪ. Multiplex PCR ﺑﻪ ﻣﻨﻈﻮر ﺑﺮرﺳـﯽ ﺣﻀـﻮر ژن ﻫـﺎي oxa24 ، oxa23 و oxa58 اﻧﺠـﺎم ﺷـﺪ. اﻟﮕـﻮي ژﻧﺘﯿﮑﯽ اﯾﺰوﻟﻪ ﻫﺎ ﺑﻪ روش ﭘﺎﻟﺲ ﻓﯿﻠﺪ ژل اﻟﮑﺘﺮﻓﻮرزﯾﺲ )PFGE( و ﺑﺎ اﺳﺘﻔﺎده از آﻧﺰﯾﻢ ApaI ﺷﻨﺎﺳﺎﯾﯽ ﺷﺪ. ﯾﺎﻓﺘﻪ ﻫﺎ: از ﻣﯿﺎن 92 اﯾﺰوﻟﻪ، 81 )%88( اﯾﺰوﻟﻪ داراي ژن oxa23 ﺑﻮدﻧﺪ. در اﯾﻦ ﻣﻄﺎﻟﻌﻪ، 72 ﭘﺎﻟﺴﻮﺗﺎﯾﭗ Pulsotype, PT ﺷﻨﺎﺳـﺎﯾﯽ ﺷﺪ ﮐﻪ از اﯾﻦ ﻣﯿﺎن، 61 ﭘﺎﻟﺴﻮﺗﺎﯾﭗ داراي ﯾﮏ اﯾﺰوﻟﻪ ﺑﻮدﻧﺪ، در ﺣﺎﻟﯽ ﮐﻪ در ﻫﺮ ﯾﮏ از 11 ﭘﺎﻟﺴﻮﺗﺎﯾﭗ دﯾﮕﺮ، دو اﯾﺰوﻟﻪ ﯾﺎ ﺑﯿﺸـﺘﺮ ﮐﻼﺳـﺘﺮ ﺷﺪﻧﺪ. ﻧﺘﯿﺠﻪ ﮔﯿﺮي: اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺮ ﺗﻮزﯾﻊ ﭘﻠﯽ ﮐﻠﻮﻧﺎل اﯾﺰوﻟﻪ ﻫﺎي اﺳﯿﻨﺘﻮﺑﺎﮐﺘﺮ ﺑﻮﻣﺎﻧﯽ ﻣﻘﺎوم ﺑﻪ ﮐﺎرﺑﺎﭘﻨﻢ ﺣﺎﻣﻞ ژنoxa23 در ﺑﯿﻤﺎرﺳﺘﺎن ﻫـﺎي ﻣﻨﺘﺨﺐ دﻻﻟﺖ دارد. ﺑﺮﺧﯽ از اﯾﺰوﻟﻪ ﻫﺎي ﺣﺎﻣﻞ ژن oxa23 ، در ﺑﺮﺧﯽ از ﺑﯿﻤﺎرﺳﺘﺎن ﻫﺎي ﻣـﻮرد ﻣﻄﺎﻟﻌـﻪ ﺑـﻪ ﻣـﺪت ﭼﻨـﺪﯾﻦ ﻣـﺎه، ﻗﺎﺑـﻞ ردﯾﺎﺑﯽ ﺑﻮدﻧﺪ.

Background and objective The first imipenem-resistant A. baumannii emerged shortly after the introduction and therapeutic use of carbapenems, particularly imipenem. The resistance to imipenem in this strain was found to be associated with oxa23 which is the most widespread gene conferring resistance to carbapenems. Because of the wide distribution of oxa23 in Iranian isolates, identifying the genotypes of endemic or circulating isolates in hospitals is of prime importance. This study aimed to identify the genotypes of carbapenem resistant A. baumannii isolates carrying oxa23 recovered from clinical specimens in selected hospitals of Tehran. Materials and methods A set of 92 A. baumannii isolates was collected and identified. Antibiotic susceptibility testing was performed by disk diffusion. A multiplex PCR was done for screening oxa23, oxa24 and oxa58 genes. The genetic pattern of the isolates was identified by Pulsed Field Gel Electrophoresis (PFGE) using ApaI enzyme. Results Of the 92 isolates, 81 (88%) harbored oxa23. In the current study, 72 distinct pulsotypes were identified and of them 61 pulsotypes contained only one isolate while in the remaining 11 pulsotypes, two or more isolates were clustered. Conclusion This study showed the polycloncal distribution of the carbapenem resistant A. baumannii isolates carrying oxa23 in selected hospitals. Some of the isolates carrying oxa23 were detected for several months in target hospitals.