Karbapenemlere dirençli pseudomonas aeruginosa kökenlerinde metallo beta laktamaz enzimlerinin fenotipik ve moleküler yöntemlerle araştırılması
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Dosyalar
Tarih
2013
Yazarlar
Dergi Başlığı
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Cilt Başlığı
Yayıncı
Trakya Üniversitesi Tıp Fakültesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Karbapenemlere dirençli Pseudomonas aeruginosa kökenleri, tedavide ciddi sorunlara neden olmaktadır. Pseudomonas aeruginosa kökenlerinde karbapenem grubu antibiyotiklere dirençte rol oynayan en önemli mekanizmalardan biri metallo beta laktamaz enzimlerinin bulunmasıdır ve çok sayıda enzim tanımlanmıştır. Metallo beta laktamaz genleri kromozom ya da plazmid üzerinde bulunur ve farklı bakteri kökenleri arasında kolayca yayılabilmektedir. Bu enzimlerin aktivitesi çinko bağımlıdır ve etilendiaminotetraasetik asit ile inhibe olmaktadır. Bu yüzden metallo beta laktamaz tanımlama testlerinde bu özellikten yararlanılmaktadır. Bu çalışmada Edirne'de metallo beta laktamaz enzimlerinin araştırılması amaçlandı. Karbapenemlere orta duyarlı/dirençli Pseudomonas aeruginosa kökenlerinde metallo beta laktamaz varlığı, fenotipik ve genotipik yöntemlerle araştırıldı. Beş fenotipik test uygulandı. Ardından blaIMP, blaVIM, blaGIM, blaSIM, blaSPM genleri multipleks, blaNDM geni ise polimeraz zincir reaksiyonu ile araştırıldı. Pseudomonas aeruginosa kökenlerinde, E-test ile %54.2, 0.5 M ve 0.1 M etilendiaminotetraasetik asit ile yapılan kombine disk difüzyon testiyle sırasıyla %94.2 ve %37.1, çift disk sinerji testiyle %42.8 oranında pozitiflik saptandı. Modifiye Hodge testiyle metallo beta laktamaz pozitifliği saptanmadı. E teste göre Çift disk sinerji testi (%80) ve 0.1 M etilendiaminotetraasetik asit ile yapılan kombine disk difüzyon testi (%76) duyarlılık oranları yüksek bulundu (sırasıyla p=0.008, p=0.03). Genotipik yöntemlerle kökenlerde aranılan metallo beta laktamaz genleri saptanmadı. Pseudomonas'larda karbapenem direncinden sorumlu olan en yaygın metallo beta laktamazlara Edirne'de rastlanılmadı. Fenotipik test sonuçlarının kendi aralarında değerlendirmesi yapılırken yüksek özgüllük ve duyarlılık gösterdiği bildirilen E-teste göre karşılaştırılmasının her zaman uygun olmadığı fark edildi. Fenotipik test sonuçlarının doğru değerlendirilmesi için bölgede yaygın bulunan direnç genlerinin moleküler yöntemlerle araştırılması gerekmektedir. Hastanemizden izole edilen kökenlerde karbapenem direncinden farklı mekanizmaların sorumlu olabileceği düşünüldü.Anahtar Kelimeler: Pseudomonas aeruginosa, metallo beta laktamaz, multipleks polimeraz zincir reaksiyonu
Abstract
Carbapenem resistant Pseudomonas aeruginosa strains causes serious problems in treatment. A large number of identified metallo beta lactamase enzymes produce by Pseudomonas aeruginosa are the one of the most important mechanism in the resistance to carbapenems. Metallo beta lactamase genes are located on chromosome or plasmid and they can easily spread between the different bacterial strains. The activities of these enzymes are zinc-dependent and they are inhibited by ethylenediaminetetraacetic acid. Therefore, this advantage is used in metallo beta lactamase identification tests. In this study, it was aimed to determine the metallo beta lactamase among P. aeruginosa strains isolated in Edirne. The existence of metallo beta lactamase enzymes in carbapenems moderately resistant/susceptible Pseudomonas aeruginosa strains were investigated by phenotypic and genotypic tests. Five phenotypic tests were used. And then, blaIMP, blaVIM, blaGIM, blaSIM, blaSPM genes and blaNDM gene were investigated by multiplex and polimerase chain reaction, respectively. Among the carbapenems resistant Pseudomonas aeruginosa isolates, positivity of metallo beta lactamase was found as 54.2% by E-test, 42.8% by double disk synergy test, 94.2% and 37.1% by combined disk diffusion method by using 0.5 M and 0.1 M ethylenediaminetetraacetic acid, respectively. The metallo beta lactamases in all these strains were detected as negative by modified Hodge test. The susceptibility rates were higher in double disk synergy test (80%) and combined disk diffusion test by using 0.1 M ethylenediaminetetraacetic acid (76%) according to E-test (p=0.008 and p=0.03, respectively). In Pseudomonas aeruginosa strains, metallo beta laktamase genes were not detected by applied genotypic methods. The most common metallo beta laktamase enzymes responsible for resistance to carbapenem in Pseudomonas were not observed in Edirne. It was realized that to compare the phenotypic test results according to metallo beta laktamase E-test, which was reported with a high sensitivity and specificity, was not appropriate always during the interpretation of the phenotypic test results between each other. In order to evaluation correctly of the phenotypic test results is also required to investigation of resistance genes is most common in the region, by molecular methods. It was thought that the different mechanisms might be responsible for the identified carbapenem resistance at strains isolated in our hospital.Keywords: Pseudomonas aeruginosa, metallo beta laktamase, multiplex polymerase chain reaction
Abstract
Carbapenem resistant Pseudomonas aeruginosa strains causes serious problems in treatment. A large number of identified metallo beta lactamase enzymes produce by Pseudomonas aeruginosa are the one of the most important mechanism in the resistance to carbapenems. Metallo beta lactamase genes are located on chromosome or plasmid and they can easily spread between the different bacterial strains. The activities of these enzymes are zinc-dependent and they are inhibited by ethylenediaminetetraacetic acid. Therefore, this advantage is used in metallo beta lactamase identification tests. In this study, it was aimed to determine the metallo beta lactamase among P. aeruginosa strains isolated in Edirne. The existence of metallo beta lactamase enzymes in carbapenems moderately resistant/susceptible Pseudomonas aeruginosa strains were investigated by phenotypic and genotypic tests. Five phenotypic tests were used. And then, blaIMP, blaVIM, blaGIM, blaSIM, blaSPM genes and blaNDM gene were investigated by multiplex and polimerase chain reaction, respectively. Among the carbapenems resistant Pseudomonas aeruginosa isolates, positivity of metallo beta lactamase was found as 54.2% by E-test, 42.8% by double disk synergy test, 94.2% and 37.1% by combined disk diffusion method by using 0.5 M and 0.1 M ethylenediaminetetraacetic acid, respectively. The metallo beta lactamases in all these strains were detected as negative by modified Hodge test. The susceptibility rates were higher in double disk synergy test (80%) and combined disk diffusion test by using 0.1 M ethylenediaminetetraacetic acid (76%) according to E-test (p=0.008 and p=0.03, respectively). In Pseudomonas aeruginosa strains, metallo beta laktamase genes were not detected by applied genotypic methods. The most common metallo beta laktamase enzymes responsible for resistance to carbapenem in Pseudomonas were not observed in Edirne. It was realized that to compare the phenotypic test results according to metallo beta laktamase E-test, which was reported with a high sensitivity and specificity, was not appropriate always during the interpretation of the phenotypic test results between each other. In order to evaluation correctly of the phenotypic test results is also required to investigation of resistance genes is most common in the region, by molecular methods. It was thought that the different mechanisms might be responsible for the identified carbapenem resistance at strains isolated in our hospital.Keywords: Pseudomonas aeruginosa, metallo beta laktamase, multiplex polymerase chain reaction
Açıklama
Tıpta Uzmanlık Tezi
Anahtar Kelimeler
Pseudomonas Aeruginosa, Metallo Beta Laktamaz, Multipleks Polimeraz Zincir Reaksiyonu, Metallo Beta Laktamase, Multiplex Polymerase Chain Reaction
