Distribution of Gram Negative Isolates in Blood Cultures and Their Antibiotic Resistance

AimIn our study, we aimed to report the distribution as well as antimicrobial susceptibility profiles of negative bacteria in the blood cultures in our hospital in order to direct the clinicians.Materials and MethodsWe worked with blood cultures which were sent to our microbiology laboratory between 2014 and 2015 by using automated blood culture system.The identification of isolates and the antibiotic susceptibilities were controlled by using conventional automated methods. Antibiotic susceptibility was determined according to the recommendations of Clinical and Laboratory Standards Institute.ResultsAccording to our results, the most frequently isolated bacteria from patient blood cultures were E. coli (32.1%), Acinetobacter spp. (%26.1), K. pneumoniae (17.1%) and P. aureuginosa (9.5%) respectively. The 38% of the E. Coli isolates, 62% of K. pneumonia isolates, 63% of P. aureuginosa isolates, %86 of Acinetobacter spp. isolates were isolated from samples which were obtained from intensive care units.All isolates were susceptible to colistin. E. coli isolates were mostly susceptible to imipenem and amikacin; Pseudomonas spp. isolates were mostly susceptible to amikacin and gentamicin; Acinetobacter spp. isolates were mostly susceptible to amikacin and trimethoprim-sulfamethoxazole; and K. pneumonia isolates were mostly susceptible to imipenem and amikacin.ConclusionWe found interesting results related to the high antibiotic resistance rates particularly against Acinetobacter spp. isolates and the abundance of gram negative bacteria in blood cultures obtained from inpatients in the intensive care units. It will be beneficial to determine the types of bacteria in blood cultures and their antibiotic susceptibilities in order to direct the empirical antibiotic use in hospitals

Distribution of Gram Negative Isolates in Blood Cultures and Their Antibiotic Resistance

Amaç Çalışmamızda ampirik tedavi gereken durumlarda klinisyenlere yol gösterebilmesi amacıyla hastanemizde kan kültürlerinde üreyen gram negatif bakterilerin dağılımının ve antimikrobiyal duyarlılık profillerinin ortaya konması amaçlandı. Materyal ve Metot Mikrobiyoloji Laboratuvarı’na 2014-2015 yılları arasında gönderilen kan numuneleri, otomatize kan kültür sistemi ile çalışıldı. İzolatların identifikasyonu ve antibiyotik duyarlılıkları konvansiyonel ve otomatize yöntemler. Sonuçlar Clinical and Laboratory Standards Institute kriterlerine göre incelendi. Bulgular Çalışmamızda gram negatif bakteriler arasında en sık izole edilenleri sırasıyla E. coli (%32,1) Acinetobacter spp. (%26,1), K. pneumoniae (%17,1) ve P. aureuginosa(%9,5) olarak saptandı. Kan kültürlerinde üremiş olan E. coli izolatlarının % 38 i, K. pneumoniae izolatlarının %62 si P. aureuginosa izolatlarının %63 ü, Acinetobacter spp. izolatlarının %86 sı yoğun bakım servislerinden izole edilmiştir. Tüm izolatların en duyarlı olduğu antibiyotik kolistin olmakla birlikte E. coli izolatlarının en duyarlı olduğu antibiyotikler imipenem ve amikasin, Pseudomonas spp. izolatlarının en duyarlı olduğu antibiyotikler amikasin ve gentamisin,Acinetobacter spp. izolatlarının en duyarlı olduğu antibiyotikler amikasin ve timetropim sülfametaksazol, K. pneumoniae izolatlarının en duyarlı olduğu antibiyotikler ise imipenem ve amikasin olarak saptanmıştır. Sonuç Özellikle Acinetobacter spp. izolatlarına karşı görülen yüksek direnç oranları ve yoğun bakım ünitelerinde yatan hastalardan izole edilmiş olan gram negatif bakterilerin çokluğu dikkat çekmiştir. Hastanelerde ampirik antibiyotik kullanımında yol gösterici olması açısından kan kültürü örneklerinde üremiş olan bakterilerin ve antibiyotik duyarlılıklarının belirlenmesi faydalı olacaktır.Aim In our study, we aimed to report the distribution as well as antimicrobial susceptibility profiles of negative bacteria in the blood cultures in our hospital in order to direct the clinicians. Materials and Methods We worked with blood cultures which were sent to our microbiology laboratory between 2014 and 2015 by using automated blood culture system.The identification of isolates and the antibiotic susceptibilities were controlled by using conventional automated methods. Antibiotic susceptibility was determined according to the recommendations of Clinical and Laboratory Standards Institute. Results According to our results, the most frequently isolated bacteria from patient blood cultures were E. coli (32.1%), Acinetobacter spp. (%26.1), K. pneumoniae (17.1%) and P. aureuginosa (9.5%) respectively. The 38% of the E. Coli isolates, 62% of K. pneumonia isolates, 63% of P. aureuginosa isolates, %86 of Acinetobacter spp. isolates were isolated from samples which were obtained from intensive care units.All isolates were susceptible to colistin. E. coli isolates were mostly susceptible to imipenem and amikacin; Pseudomonas spp. isolates were mostly susceptible to amikacin and gentamicin; Acinetobacter spp. isolates were mostly susceptible to amikacin and trimethoprim-sulfamethoxazole; and K. pneumonia isolates were mostly susceptible to imipenem and amikacin. Conclusion We found interesting results related to the high antibiotic resistance rates particularly against Acinetobacter spp. isolates and the abundance of gram negative bacteria in blood cultures obtained from inpatients in the intensive care units. It will be beneficial to determine the types of bacteria in blood cultures and their antibiotic susceptibilities in order to direct the empirical antibiotic use in hospitals