Publication: İnvaziv örneklerden izole edilen Escherichia coli suşlarının aminoglikozid antibiyotiklere direncinin araştırılması
Abstract
Amaç: Hastanemizde izole edilen invaziv Escherichia coli izolatlarında aminoglikozid direncinden sorumlu mekanizmaları ortaya koymaktır.Gereç ve Yöntem: Marmara Üniversitesi Hastanesi’nde Ocak-Aralık 2016 tarihleri arasında izole edilen 156 invaziv E. coli izolatı çalışmaya alınmıştır. VITEK 2 Compact (bioMérieux, France) ile amikasin ve/ veya gentamisine dirençli saptanan 50 izolatta; amikasin, gentamisin, tobramisin, netilmisin, apramisin ve kanamisin minimum inhibitor konsantrasyonları (MİK) standart sıvı mikrodilüsyon yöntemiyle belirlenmiştir. Elli izolatta ayrıca aminoglikozid modifikasyon enzimlerini kodlayan genler (aac(3)-II, aac(3)-I, aac)6’)-Ib, ant(2’’)-I), PZT yöntemiyle araştırılmıştır.Bulgular ve Sonuçlar: Çalışmamızda, E. coli izolatlarına en etkili aminoglikozidin amikasin olduğu (%94) saptanmıştır. İzolatlarımızın %80’inde (40/ 50) aac(3)-II, %54’ünde (27/ 50) aac(6’)-Ib ve %4’ünde (2/ 50) ant(2‘’)-I genleri tek başına veya birlikte saptanmıştır. aac(6')-Ib ve aac(3)-II birlikteliği izolatların %34’ünde (17/ 50) bulunmuştur. Direnç fenotipi ile direnç genlerinin varlığı arasında uyum saptanmıştır. Hastanemizde aminoglikozid direncine yol açan temel mekanizma aminoglikozid modifikasyon enzimlerini kodlayan aac(3)-II ve aac(6’)-Ib‘dir.
Aim: The purpose of this study is to determine aminoglycoside resistance mechanisms in Escherichia coli isolates collected in our University Hospital. Material and Method: A total of 156 invasive E. coli isolates collected in 2016 at Marmara University Hospital were included in the study. Fifty isolates which were found to be resistant to amikacin and/ or gentamicin in VITEK 2 Compact (bioMérieux, France) were run to standart broth microdilution test to determine amikacin, netilmicin, gentamicin, tobramycin, kanamycin, apramycin MICs. The four genes (aac(3)-II, aac(3)-I, aac)6’)-Ib, ant(2’’)-I) encoding common aminoglicoside modifying enzymes were investigated by PCR.Results and Conclusion: Amikacin was the most active aminoglycoside with 94% susceptibility rate in E. coli isolates. aac(3)-II, aac(6’)-Ib and ant(2‘’)-I genes alone or together were determined in 80% (40/ 50), 54% (27/ 50), and 4% (2/ 50) of the isoltes, respectively. In %34 (17/ 50) of the isoltes, aac(6')-Ib and aac(3)-II genes were found together. A general concordance was found between resistance phenotype and genetic determinants of resistance. Main mechanisms that cause aminoglycoside resistance in our hospital’s samples are aac(3)-II and aac(6’)-Ib, which encode aminoglycoside modifying enzymes.
Aim: The purpose of this study is to determine aminoglycoside resistance mechanisms in Escherichia coli isolates collected in our University Hospital. Material and Method: A total of 156 invasive E. coli isolates collected in 2016 at Marmara University Hospital were included in the study. Fifty isolates which were found to be resistant to amikacin and/ or gentamicin in VITEK 2 Compact (bioMérieux, France) were run to standart broth microdilution test to determine amikacin, netilmicin, gentamicin, tobramycin, kanamycin, apramycin MICs. The four genes (aac(3)-II, aac(3)-I, aac)6’)-Ib, ant(2’’)-I) encoding common aminoglicoside modifying enzymes were investigated by PCR.Results and Conclusion: Amikacin was the most active aminoglycoside with 94% susceptibility rate in E. coli isolates. aac(3)-II, aac(6’)-Ib and ant(2‘’)-I genes alone or together were determined in 80% (40/ 50), 54% (27/ 50), and 4% (2/ 50) of the isoltes, respectively. In %34 (17/ 50) of the isoltes, aac(6')-Ib and aac(3)-II genes were found together. A general concordance was found between resistance phenotype and genetic determinants of resistance. Main mechanisms that cause aminoglycoside resistance in our hospital’s samples are aac(3)-II and aac(6’)-Ib, which encode aminoglycoside modifying enzymes.