Comparison of the Results of the Microdilution and Automated System in Determination of Colistin Resistance

Year 2020, Volume: 10 Issue: 3, 297 - 301, 21.09.2020

Yeliz Tanrıverdi Canberk Çınar Kemal Bilgin Demet Gür Vural Asuman Birinci

https://doi.org/10.33631/duzcesbed.603411

Abstract

Aim: Colistin is one of theantibiotics with increasing usage in the treatment of multidrug-resistant Gram-negative bacteria. The Mueller-Hinton broth microdilution (BMD) method proposed by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) is the gold standard for the determination of sensitivity. The aim of this study was to compare the sensitivity of the Vitek2 Compact automated device with BMD results.
Material and Methods: Total of 126 Gram negative isolates participated in the study. Colistin sensitivity of the isolates was determined by Vitek2 Compact automated system and BMD method.
Results: Sixteen of 126 isolates in the automated system were found to be colistin resistant (12.7%). Colistin resistance was found in 34 (126%) out of 126 isolates with BMD. These two methods, the categorical adjustment (KU) ratio for the automated system was found to be 84.12%, majör error (BH) was 1.09%, and very large error (MDI) was 55.88%. The minimum inhibitory concentration values (MIC50 and MIC90) of the isolates studied in the automated system were 0.5 μg / ml and16 μg / ml. The MIC50 and MIC90 values of the results obtained by BMD method were 0.5 μg / ml and 2 μg / ml.
Conclusion: When the automated system results are examined, it is seen that the rate of resistant isolates is less. With these results it is seen that resistant isolates can be overlooked in automated system. In the sensitivity of colistin, it was seen that the automated system did not fully meet the expectations.

Keywords

Antimicrobial susceptibility, colistin, broth microdilution

Kolistin Direncinin Saptanmasında Sıvı Mikrodilüsyon ve Otomatize Sistem Sonuçlarının Karşılaştırılması

Abstract

Amaç: Kolistin çok ilaca dirençli Gram negatif bakterilerin tedavisinde kullanımı artan antibiyotiklerden biridir. Duyarlılığının belirlenmesinde European Committee on Antimicrobial Susceptibility Testing (EUCAST) tarafından önerilen Mueller-Hinton buyyonda sıvı mikrodilüsyon (BMD) yöntemi altın standart olarak belirlenmiştir. Bu çalışmada Vitek2 Compakt otomatize cihazının belirlediği duyarlılık sonucuyla BMD yönteminin sonuçlarının karşılaştırılması amaçlanmıştır.
Gereç ve Yöntemler: Çalışmaya 126 Gram negatif izolat dahil edilmiştir. Bu izolatların kolistin duyarlılığı Vitek2 Compakt otomatize sistemiyle belirlenmiş olup tüm örneklerin kolistin duyarlılığı BMD yöntemi ile de çalışılmıştır.
Bulgular Otomatize sistemde 126 izolatın 16 tanesi kolistin dirençli olarak bulunmuştur (%12,7). BMD yönteminde 126 izolatın 34 tanesi kolistin dirençli olarak bulunmuştur (%27). İki yöntem karşılaştırıldığında otomatize sistem için kategorik uyum (KU) oranı %84,12, büyük hata (BH) oranı %1,09, çok büyük hata (ÇBH) oranı da %55,88 olarak saptanmıştır. Otomatize sistem ile incelenen izolatların minimum inhibitör konsantrasyon değerleri (MİK50 ve MİK90) sırasıyla 0,5 μg/ml ve 16 μg/ml olup BMD yöntemi ile elde edilen sonuçların MİK50 ve MİK90 değerleri sırasıyla 0,5 μg/ml ve 2 μg/ml olarak bulunmuştur.
Sonuç: Otomatize sistem sonuçlarına bakıldığında dirençli izolat sayısının daha az olduğu görülmektedir. Bu sonuçlar ile otomatize sistemde dirençli olan izolatların gözden kaçabileceği görülmektedir. Kolistin duyarlılığında EUCAST’ın önerdiği BMD yönteminin kullanılmasının gerekliliği ve otomatize sistemlerin beklentileri tam olarak karşılamadığı bu çalışma ile vurgulanmıştır.

Keywords

kolistin, Antimikrobiyal duyarlılık, sıvı mikrodilüsyon

References

• 1. Pereira GH, Garcia DO, Mostardeiro M, Fanti KS, Levin AS. Outbreak of carbapenemresistant Klebsiella pneumoniae: two-year epidemiologic follow-up in a tertiary hospital. Mem Inst Oswaldo Cruz. 2013; 108(1): 113-5.
• 2. Öztürk O, Öztürk C, Delialioğlu N, Emekdaş G. Çoklu antibiyotik dirençli gram negatif bakterilerde kolistin duyarlılığının belirlenmesi. Mersin Üniversitesi Sağlık Bilimleri Dergisi. 2010; 3(3): 15-20.
• 3. Kılınç Ç, Güçkan R, Kahveci M, Kayhan Y, Pirhan Y, Özalp T. Kan kültürlerinde üreyen gram negatif izolatların dağılımı ve antibiyotik direnç profilleri. Int J Basic Clin Med. 2015; 3(3): 125-30.
• 4. Arman D. Yoğun bakımda gram negatif bakteri sorunu. Ankem Derg. 2009; 23: 148-56.
• 5. Kaye KS, Pogue JM, Tran TB, Nation RL, Li J. Agents of last resort: Polymyxin resistance. Infect Dis Clin North Am. 2016; 30(2): 391-414.
• 6. Koçak CÖ, Hazırolan G. Karbapenem dirençli Klebsiella pneumoniae klinik izolatlarında kolistin direnci. Türk Mikrobiyoloji Cem Derg. 2019; 49(1): 17-23.
• 7. Nordmann P, Cuzon G, Naas T. The real threat of Klebsiella pneumoniae carbapenemase-producing bacteria. Lancet Infect Dis. 2009; 9(4): 228-36.
• 8. Grégoire N, Aranzana-Climent V, Magréault S, Marchand S, Co¬uet W. Clinical pharmacokinetics and pharmacodynamics of co¬listin. Clin Pharmaco kinet. 2017; 56(12): 1441-60.
• 9. eucast.org [Internet]. European Committee on Antimicrobial Susceptibility Testing. Breakpoint tables for interpretation of MICs and zone diameters. Version7.1 Basel: EUCAST [Cited: March 2018]. Available from: http://www.eucast.org/ast_of_bacteria/pre-vious_versions_of_documents/.
• 10. eucast.org [Internet]. European Committee on Antimicrobial Susceptibility Testing. Recommendations for MIC determination of colistin (polym¬yxin E). As recommended by the joint CLSI-EUCAST Polymyxin Breakpoints Working Group. Basel: EUCAST [Cited March 2018]. Available from: http://www.eucast.org/ast_of_bacteria/pre-vious_versions_of_documents/.
• 11. Clinical and Laboratory Standards Institute. Development of In Vitro Susceptibility Testing Criteria and Quality Control Parame¬ters. Approved Guideline. 3rd ed. CLSI document M23-A3. Way¬ne, PA: CLSI, 2008.
• 12. International Organization for Standardization. ISO 20776-2:2007. Clinical laboratory testing and in vitro diagnostic test systems. Susceptibility testing of infectious agents evalua¬tion of performance of antimicrobial susceptibility test devices - Part 2: Evaluation of performance of antimicrobial susceptibility test devices. Geneva: ISO. Dis Clin North Am. 2016; 30(2): 391-414. https://www.iso.org/standard/41631.html.
• 13. Vasoo S. Susceptibility testing for the polymyxins: two steps back, three steps forward? J Clin Microbiol. 2017; 55(9): 2573-82.
• 14. Humphries RM. Susceptibility testing of the polymyxins: where are we now? Pharmacotherapy. 2015; 35(1): 22-7.
• 15. Lo-Ten-Foe JR, de Smet AM, Diederen BM, Kluytmans JA, van Keulen PH. Comparative evaluation of the Vitek 2, disk diffu¬sion, Etest, broth microdilution, and agar dilution susceptibi¬lity testing methods for colistin in clinical isolates, including heteroresistant Enterobacter cloacae and Acinetobacter bau¬manii strains. Antimicrob Agents Chemo Ther. 2007; 51(10): 3726-30.
• 16. Eucast [Internet]. Recommendations for MIC determination of colistin (polymyxin E) As recommended by the joint CLSI-EUCAST Polymyxin Breakpoints Working Group. 2016 [Cited: December 2018]. Available from: http://www.eucast.org/fileadmin/src/media/PDFs/EUCAST_files/General_documents/Recommendations_for_MIC_determination_of_colistin_March_2016.pdf.
• 17. Tan TY, Ng SY. Comparison of E test, Vitek and agar dilution for susceptibility testing of colistin. Clin Microbiol Infect. 2007; 13(5): 541-4.
• 18. Chew KL, La MV, Lin RT, Teo JW. Colistin and polymyxin B sus¬ceptibility testing for carbapenem-resistantand mcr-positive En¬terobacteriaceae: comparison of Sensititre, Microscan, Vitek 2, and E test with broth microdilution. J ClinMicrobiol. 2017; 55(9): 2609-16.
• 19. Lee SY, Shin JH, Lee K, et al. Comparison of the Vitek 2, Mic¬roScan, and Etest methods with the agar dilution method in assessing colistin susceptibility of blood stream isolates of Aci¬netobacter species from a Korean university hospital. J Clin Microbiol. 2013; 51(6): 1924-6.
• 20. Dafopoulou K, Zarkotou O, Dimitroulia E, et al. Comparative eva¬luation of colistin susceptibility testing methods among carba¬penem-nonsusceptible Klebsiella pneumoniae and Acinetobac¬ter baumannii clinical isolates. Antimicrob Agents Chemo ther. 2015; 59(8): 4625-30.
• 21. Rojas LJ, Salim M, Cober E, et al. Colistin resistance in carbapenem-resistant Klebsiella pneumoniae: laboratory detection and impact on mortality. Clin Infect Dis. 2017; 64(6): 711-8.
• 22. Tüzemen NÜ, Efe K, Akalın H, Özakın C. Retrospective evaluation of colistin-resistant isolates in automated system by gradient diffusion method and broth microdilution method. Klimik Derg. 2019; 32(1): 57-61.
• 23. Giske CG, Kahlmeter G. Colistin antimicrobial susceptibility tes¬ting can the slow and challenging be replaced by the rapid and convenient? Clin Microbiol Infect. 2018; 24(2): 93-4.