شيوع ژن هاي كد كننده مقاومت آمينوگليكوزيدي در استافيلوكوكوس اورئوس حساس به متي سيلين و استافيلوكوكوس كواگولاز منفي جد اشده از عفونت هاي بيمارستاني

Prevalence of genes encoding aminoglycoside resistant in methicillin-sensitive Staphylococcus aurous and coagulasenegative staphylococci isolated from hospital infectious

ﺳﺎﺑﻘﻪ و ﻫﺪف: اﺳﺘﺎﻓﯿﻠﻮﮐﻮﮐﻮس ﻫﺎ ﯾﮑـﯽ از راﯾـﺞ ﺗـﺮﯾﻦ ﻋﻮاﻣـﻞ ﻋﻔﻮﻧـﺖ ﻫـﺎ ي ﺑﯿﻤﺎرﺳـﺘﺎني ﺑـﻪ ﺷـﻤﺎر ﻣـي روﻧـﺪ. آﻣﯿﻨﻮﮔﻠﯿﮑﻮزﯾﺪﻫﺎ اﻏﻠﺐ ﺑﻪ ﺻﻮرت ﺗﺮﮐﯿﺐ ﺑﺎ ﺑﺘﺎﻻﮐﺘﺎم ﻫﺎ ﯾﺎ ﮔﻠﯿﮑﻮﭘﭙﺘﯿﺪﻫﺎ در درﻣﺎن اﻧـﺪوﮐﺎردﯾﺖ و ﺑـﺎﮐﺘﺮﯾﻤﯽ ﻧﺎﺷﯽ از اﺳﺘﺎﻓﯿﻠﻮﮐﻮﮐﻮس ﻫﺎ اﺳﺘﻔﺎده ﻣﯽﺷﻮﻧﺪ. ﻣﮑﺎﻧﯿﺴﻢ اﺻﻠﯽ ﻣﻘﺎوﻣﺖ آﻣﯿﻨﻮﮔﻠﯿﮑﻮزﯾﺪي در اﺳﺘﺎﻓﯿﻠﻮﮐﻮﮐﻮس ﻫﺎ ﻏﯿﺮ ﻓﻌﺎلﺳﺎزي دارو ﺑﻪ وﺳﯿﻠﻪ آﻧﺰﯾﻢ ﻫﺎي ﺗﻐﯿﯿﺮ دﻫﻨﺪه آﻣﯿﻨﻮ ﮔﻠﯿﮑﻮزﯾﺪي ﺳﻠﻮﻟﯽ ﻣﯽ ﺑﺎﺷﺪ. ﻣﻮاد و روش ﻫﺎ: 50 اﯾﺰوﻟﻪ اﺳﺘﺎﻓﯿﻠﻮﮐﻮﮐﻮس اورﺋﻮس ﺣﺴﺎس ﺑﻪ ﻣﺘﯽ ﺳﯿﻠﯿﻦ و 50 اﯾﺰوﻟـﻪ اﺳـﺘﺎﻓﯿﻠﻮﮐﻮﮐﻮس ﮐﻮاﮔـﻮﻻز ﻣﻨﻔﯽ از ﻧﻤﻮﻧﻪ ﻫﺎي ﻣﺨﺘﻠﻒ ﺑﺎﻟﯿﻨﯽ ﺟﻤﻊ آوري ﮔﺮدﯾﺪ و ﺗﻮﺳﻂ ﺗﺴﺖ ﻫﺎي ﺑﯿﻮﺷﯿﻤﯿﺎﯾﯽ اﺳﺘﺎﻧﺪارد ﺗﻌﯿﯿﻦ ﻫﻮﯾﺖ ﺷﺪ. اﻟﮕﻮي ﺣﺴﺎﺳﯿﺖ آﻧﺘﯽ ﺑﯿﻮﺗﯿﮑﯽ در اﯾﺰوﻟـﻪﻫـﺎ ﺑـﺎ اﺳـﺘﻔﺎده از روش دﯾﺴـﮏ د ﯾﻔﯿـﻮژن وEtestٍ ﺑـﺮ اي آﻧﺘـﯽ ﺑﯿﻮﺗﯿﮏ ﻫـﺎي آﻣﯿﻨﻮﮔﻠﯿﮑﻮزﯾﺪي ﺗﻌﯿﯿﻦ ﺷﺪ و ﺳﭙﺲ ﻓﺮاواﻧﯽ ژن ﻫﺎي 2 (aph(3')-IIIa ،aac(6')-Ie-aph و ant(4')-Ia ﺑﺎ اﺳﺘﻔﺎده از روش PCR ﻣﺸﺨﺺ ﮔﺮدﯾﺪ. ﯾﺎﻓﺘﻪ ﻫﺎ: 26% از ﻧﻤﻮﻧﻪ ﻫﺎ ﺣﺪاﻗﻞ ﺑﻪ ﯾﮑﯽ از آﻧﺘﯽ ﺑﯿﻮﺗﯿﮏ ﻫﺎ ﻣﻘﺎوﻣﺖ ﻧﺸﺎن ﻣﯽ دادﻧﺪ. ژن ﻫـﺎ ي 2(aac(6')-Ie/aph و aph(3')-IIIa ﺑﻪ ﺗﺮﺗﯿﺐ ﻓﺮاوان ﺗﺮﯾﻦ ژن ﻫﺎ ﺑﻮدﻧﺪ. ﺣﺪود 14% از ﮐﻞ ﻧﻤﻮﻧﻪ ﻫﺎ ﺑﻪ ﻃﻮر ﻫﻢ زﻣـﺎن دار اي دو ژن ﻓـﻮق ﺑﻮدﻧـﺪ وﻟﯽ در ﻫﯿﭻ ﻧﻤﻮﻧﻪ اي ژن ant(4')-Ia ﯾﺎﻓﺖ ﻧﺸﺪ. ﻧﺘﯿﺠﻪ ﮔﯿﺮي: ژن ﻫﺎي 2(aac(6')-Ie-aph و aph(3')-IIIa ﺷﯿﻮع ﺑﺎﻻﯾﯽ در ﺑﯿﻦ اﯾﺰوﻟﻪ ﻫﺎ داﺷﺘﻨﺪ، ﮐـﻪ ﺑـﺎ ﺗﺠـﻮ ﯾﺰ ﻣﻨﺎﺳﺐ آﻧﺘﯽ ﺑﯿﻮﺗﯿﮏ ﻣﯽ ﺗﻮان از ﺷﯿﻮع ﻣﻘﺎوﻣﺖ ﺑﯿﺶ ﺗﺮ ﺟﻠﻮﮔﯿﺮي ﻧﻤﻮد. اﺳﺘﻔﺎده از روش ﻫﺎي ﻓﻨﻮﺗﯿﭙﯽ و ژﻧﻮﺗﯿﭙﯽ ﺑﻪ ﻃﻮر ﻫﻢ زﻣﺎن اﻃﻼﻋﺎت ﮐﺎﻣﻠﯽ از ﻣﻘﺎوﻣﺖ آﻣﯿﻨﻮﮔﻠﯿﮑﻮزﯾﺪي را در اﺧﺘﯿﺎر ﻣﺎ ﻗﺮار داد.

Introduction: Staphylococci are the most common causes of nosocomial infections are considered.Aminoglycosides are often used in combination with B-lactamas and glycopeptides for the treatment of endocarditis and bacteremia caused by Staphylococci. The main mechanism of aminoglycoside resistance in staphylococci is drug inactivation by cellular aminoglycoside modifying enzymes. Materials and Methods: 50 isolates of methicillin-sensitive Staphylococcus aureus and 50 isolates coagulase-negative staphylococci, were collected from various clinical specimens and were identified by standard biochemical tests. The antibiotic susceptibility pattern of isolates using the disk diffusion method and Etest for determining aminoglycoside antibiotics and the frequency of gene aac(6')-Ie-aph(2"), aph(3')- IIIa and ant(4')-Ia was determined using PCR. Results: 26% of the samples showed resistance to at least one antibiotics.Genes aac(6')-Ie/aph(2") and aph(3')-IIIa were most abundant genes, respectively. Approximately 14% of these genes were two samples simultaneously, but in no instance a gene ant(4')-Ia were found. Conclusion: High prevalence of genes aac(6')-Ie-aph(2") and aph(3')-IIIa resistance genes among isloate were found. Proper antibiotic can be prescribed to prevent dissemination of resistant strains. Use phenotypic and genotypic methods simultaneously give us full information of aminoglycoside resistance.