Publication: Acinetobacter spp.’e karşı kullanılan kolistin aktivitesine çok düşük frekanslı elektromanyetik alanın etkisi
Abstract
Amaç: Acinetobacter baumannii suşları çoklu ilaç direnci gösteren (ÇİD)nozokomiyal kökenli enfeksiyonlardan sorumlu patojenlerdir. Kolistin ÇİD gösterenA. baumannii enfeksiyonlarına son çare olarak kabul edilmektedir. Ancak kolistindirencinin gelişmesi ciddi sağlık tehdidine neden olmaktadır. Çok düşük frekanslıelektromanyetik alanların (ÇDF-EMA) prokaryotik canlılarda çoğalmayı ketlediğigözlemlenmiştir. Bu çalışma ÇDF-EMA'nın kolistin dirençli ve duyarlı A.baumannii'nin kolistin direncine etkisini saptamayı amaçlamaktadır.Gereç ve yöntem: A. baumanni suşları 1x106 CFU/ mL elde etmek için MuellerHinton Broth ile süspense edilmiştir. Solenoid içerisinde oluşturulan ÇDF-EMAaltında 37°C’de inkübe edilmiştir. Dört farklı ÇDF-EMA parametresinde sonuçlarabakılmıştır. Her alan parametresi için farklı saatlere bakılmıştır. Üremede en fazlaazalmayı sağlayan süre ve alan parametresi kolistinin minimum inhibasyonkonsantrasyonundaki değişimi belirlenmesi için kullanılmıştır. Bakteriyel üreme ODölçümleriyle belirlenmiştir.Bulgular: ÇDF-EMA’da maruziyette her iki suş için üreme oranındaki en yüksekdüşüş, 24 saat boyunca 30 Hz 1 mT ÇDF-EMA uygulamasıyla elde edilmiştir. Buparametredeki MİK sonucunda duyarlı suş için kolistinin duyarlılığını 2 kat, dirençlisuş içinse 4 kat arttırmıştır.Sonuç: ÇDF-EMA, kolistin etkinliğini arttırmaktadır. İn-vivo deneylere ihtiyaçduyulmasına rağmen ÇİD için tedavide dikkate alınmalıdır
Objective: Acinetobacter baumannii strains are pathogens responsible for severenosocomial infections that have acquired multidrug resistance (MDR). Colistin isconsidered to be the last resort to MDR A. baumannii infections however besides itsside effects acquisition of colistin resistance cause serious health threat. Extremelylow frequency electromagnetic fields (ELF-EMF) are non-ionizing fields with afrequency of less than 300 Hz. It has been observed that it inhibits reproduction inprokaryotic organisms. This study aimed to overcome this problem by exposingcolistin resistant and susceptible A. baumannii strains to extremely lowelectromagnetic fields which have been shown to decrease bacterial growth.Material and methods: A.baumannii strains were suspended in Mueller Hintonbroth to get 1x106 CFU/ mL. ELF-EMF was generated in a solenoid and placed in anincubator. Control was in another incubator. ELF-EMF exposure was done at fourfield parameters. The duration and field parameter that produced the highest decreasein growth was chosen for colistin treatment. Bacterial growth was determined by ODmeasurements. Colistin efficacy was made by MIC test.Results: ELF-EMF exposure caused a statistically significant decrease in growthrate for both strains. The highest difference in growth rate for both strains wasobtained with 30Hz 1mT ELF-EMF exposure for 24 hours. This parameter was usedfor colistin susceptibility testing. ELF-EMF increased colistin susceptibility 2 foldfor susceptible strain and 4 fold for resistant strain.Conclusion: ELF-EMF creates a significant increase in colistin efficacy. Although invivo experiments are needed these results must be considered for therapy of MDR.
Objective: Acinetobacter baumannii strains are pathogens responsible for severenosocomial infections that have acquired multidrug resistance (MDR). Colistin isconsidered to be the last resort to MDR A. baumannii infections however besides itsside effects acquisition of colistin resistance cause serious health threat. Extremelylow frequency electromagnetic fields (ELF-EMF) are non-ionizing fields with afrequency of less than 300 Hz. It has been observed that it inhibits reproduction inprokaryotic organisms. This study aimed to overcome this problem by exposingcolistin resistant and susceptible A. baumannii strains to extremely lowelectromagnetic fields which have been shown to decrease bacterial growth.Material and methods: A.baumannii strains were suspended in Mueller Hintonbroth to get 1x106 CFU/ mL. ELF-EMF was generated in a solenoid and placed in anincubator. Control was in another incubator. ELF-EMF exposure was done at fourfield parameters. The duration and field parameter that produced the highest decreasein growth was chosen for colistin treatment. Bacterial growth was determined by ODmeasurements. Colistin efficacy was made by MIC test.Results: ELF-EMF exposure caused a statistically significant decrease in growthrate for both strains. The highest difference in growth rate for both strains wasobtained with 30Hz 1mT ELF-EMF exposure for 24 hours. This parameter was usedfor colistin susceptibility testing. ELF-EMF increased colistin susceptibility 2 foldfor susceptible strain and 4 fold for resistant strain.Conclusion: ELF-EMF creates a significant increase in colistin efficacy. Although invivo experiments are needed these results must be considered for therapy of MDR.