Kan Kültürü Şişesinden Doğrudan Yapılan Hızlı Antibiyotik Duyarlılık Testi Yönteminin Standart Disk Difüzyon Yöntemi ile Karşılaştırılması

Abstract

Amaç: Sepsis etkenlerinin antimikrobiyal duyarlılıklarının erken belirlenmesi çok önemlidir. Bu çalışmada, standart disk difüzyon yöntemi ile kan kültür şişelerinden doğrudan yapılan hızlı antibiyotik duyarlılık testi (HADT) yönteminin karşılaştırılması amaçlandı. Gereç ve Yöntemler: Çalışmaya Nisan 2019 ile Eylül 2019 tarihleri arasında kan kültürü cihazında pozitif sinyal veren örneklerden izole edilen bakteriler dahil edilmiş ve antimikrobiyal duyarlıkları standart disk difüzyon yöntemi ve HADT yöntemi ile belirlenmiştir. Kategorik uyum, küçük hata, büyük hata, çok büyük hata ve teknik belirsizlik alanı oranları kaydedilmiştir. Bulgular: Çalışmaya 19’u S. aureus, 10’u Enterococcus spp. ile 24’ü E. coli, 24’ü K. pneumoniae, 13’ü P. Aeruginosa ve 13’ü A. baumannii olmak üzere toplam 103 adet bakteri dahil edilmiştir. HADT yöntemi ile standart disk difüzyon yöntemi karşılaştırıldığında, E. coli izolatlarında imipenem, meropenem, gentamisin ve trimetoprim-sülfametoksazole karşı değerlendirilen tüm saatler için, K. pneumoniae izolatlarında ise meropeneme karşı 6. ve 8. saatler için yöntemler arasında %100 uyum bulunmuştur. S. aureus ve P. aeruginosa izolatlarında ise HADT sonuçlarında çok büyük hata saptanmıştır. A. baumannii izolatlarında birçok antibiyotik için yöntemler arasında %100 uyum olduğu görülmüştür. Sonuç: HADT yönteminin sepsis gibi hayatı tehdit eden enfeksiyonlar için kullanımı kolay ve ucuz bir test olduğu sonucuna varılmıştır. Test edilen bakteriye göre değişen uyum oranları nedeniyle benzer çalışmaların çok sayıda izolatla yapılması gerektiği de düşünülmüştür.

Keywords

• Bakteriyemi
• disk diffüzyon antimikrobiyal testleri
• EUCAST hızlı antimikrobiyal duyarlılık testi
• kan kültürü

Comparison of Rapid Antibiotic Susceptibility Test Method Directly from Blood Culture Bottle with Standard Disc Diffusion Method

Abstract

Aim: Early determination of antimicrobial susceptibility of sepsis pathogens is important. In this study, we aimed to compare the standard disc diffusion method with the rapid antimicrobial susceptibility testing (RAST) method performed directly from blood culture bottles. Material and Methods: Bacteria isolated from samples that gave a positive signal on the blood culture device between April 2019 and September 2019 were included in the study, and antimicrobial susceptibilities were determined by the standard disc diffusion method and the RAST method. Categorical agreement, small error, large error, very large error, and area of technical uncertainty ratios were recorded. Results: A total of 103 bacteria including 19 S. aureus, 10 Enterococcus spp. and 24 E. coli, 24 K. pneumoniae, 13 P. aeruginosa, and 13 A. baumannii were included in the study. When the RAST method was compared with the standard disc diffusion method, 100% agreement was found between the methods against imipenem, meropenem, gentamicin, and trimethoprim-sulfamethoxazole in E. coli isolates at all hours evaluated, and against meropenem in K. pneumoniae isolates at the 6th and 8th hour. For S. aureus and P. aeruginosa isolates, very major errors were found in the RAST results. For A. baumannii isolates, 100% agreement between methods was observed for many antibiotics. Conclusion: It was concluded that the RAST method is a simple and inexpensive test for life-threatening infections such as sepsis. It was also felt that similar studies should be carried out with a large number of isolates, as compliance rates vary depending on the bacteria tested.

Keywords

• Bacteremia
• disc diffusion antimicrobial tests
• EUCAST rapid antimicrobial susceptibility test;
• blood culture

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