Klinik Klebsiella pneumoniae İzolatlarında Karbapenemaz Üretiminin Saptanmasında Polimeraz Zincir Reaksiyonu ve Fenotipik Yöntemlerin Karşılaştırılması

Abstract

Being a member of the Enterobacteriaceae family, Klebsiella pneumoniae is an opportunistic pathogen that inhabits normal human microbiota and causes predominantly hospital-acquired infections. The emergence of K.pneumoniae isolates which are resistant particularly to the carbapenem group of antibiotics has led to an increase in hospitalization period, mortality and morbidity. Although different rates of resistance are observed between countries, regions and even healthcare facilities, there has been a rapid increase in the prevalence of carbapenem-resistant strains in the last 10 years. Fast and correct identification of carbapenem-resistant strains is important for the successful treatment of infections caused by these resistant bacteria. The objective of this study was to investigate the presence and the types of carbapenemases in carbapenem-resistant K.pneumoniae strains using "MASTDISCS™ ID carbapenemase detection disc set", a commercial product that can be used for this purpose, and "Carbapenem Inactivation Method (CIM)", a relatively new method, and compare the results of these methods by polymerase chain reaction (PCR). For this purpose, we used 54 K.pneumoniae strains isolated in 2015-2016, that were resistant to any of the ertapenem, meropenem or imipenem antibiotics. The identification of the strains was performed using VITEK MS and their antibiotic susceptibility tests were carried out using the VITEK 2 Compact® automated system. For the strains that were found resistant to carbapenems in the automated system, the minimum inhibitor concentration (MIC) values were determined by the gradient testing method according to the recommendations of "The European Committee on Antimicrobial Susceptibility Testing (EUCAST)". The blaOXA-48, blaIMP, blaNDM, blaVIM, and blaSIM genes were investigated with PCR among these isolates. Phenotypic enzyme typing was performed in the carbapenem-resistant strains using the "MASTDISCS™ ID carbapenemase detection disc set" and "Carbapenem Inactivation Method (CIM)". REP-PCR was used to reveal clonal relationship of the isolates. The 54 K.pneumoniae isolates were found as resistant to carbapenem and the MIC50 and MIC90 values of imipenem, meropenem and ertapenem were 32 µg/ml. Only 33 of the strains had blaOXA-48 and two of them had only blaNDM, the remaining 19 strains had both of these two genes. The blaIMP, blaVIM and blaSIM genes were not encountered in any of the isolates. When the isolates were assessed by the REP-PCR method, six main clones were detected. The "MASTDISCS™ ID carbapenemase detection disc set" was able to detect all the carbapenemase producing strains and it remained incapable of distinguishing OXA-48 in the strains which had both OXA-48 and metallo beta lactamase (MBL) enzymes. The CIM method showed a low rate of positivity (46.15%) in the strains containing blaOXA-48, but was found much more successful in the strains containing blaNDM with a detection rate of 85.71%. In this study, it was concluded that the Mastdiscs-ID method could be successfully used to...

Investigation of the prevalence of carbapenem resistance genes in faecal carriage of carbapenem resistant Klebsiella spp. isolates by multiplex real-time PCR method

“…The K. pneumoniae strain producing NDM carbapenemase in Turkey was first identified from the patient's blood culture in 2011 [12]. It was the second most isolated carbapenemase gene type in Turkey after OXA-48 [13][14][15][16]. In our study, while the NDM gene was single in 21 strains and co-existed with OXA-48 in 18 strains in a total of 39 NDM (78%)-carrying strains, OXA-48…”

Carbapenemase investigation with rapid phenotypic test (RESIST-4 O.K.N.V) and comparison with PCR in carbapenem-resistant Enterobacterales strains

“…In the same study, KPC was identified in four strains ( 15 ). In another study conducted in our region in 2017, no KPC-producing strain was found ( 6 ). In this study, 20 strains were found to be producing KPC.…”

“…Primers targeting the bla NDM , bla OXA-48 , bla KPC , and bla VIM were used in carbapenem-resistant isolates ( 6 , 7 ). The final ingredient of the PCR mix was prepared as; X Taq Buffer, 200 mm dNTP, 2.5 mm MgCl 2 (Taq polymerase - set dNTP, Applied Biological Materials Inc., Canada), and 50 pmol of primer pairs in a final volume of 25 μL.…”

“…Finally, the results were determined in a chemiluminescence imaging device (GEN-BOX imagER CFx, Erbiotek, Turkey) under UV light. Isolates containing relevant genes were used as the positive control ( 6 ).…”

Klebsiella pneumoniae Klinik Suşlarında, 2012-2020 Yılları Arasında Karbapenem Direnç Oranlarındaki Değişimin ve Direnç Genlerinin Araştırılması

“…IMP direnç geni Japonya ve Tayvan' da endemik iken VIM direnç geni ise Yunanistan'da endemiktir (1,5,13) . Ülkemizde yapılan çeşitli çalışmalarda, tekli direnç geni OXA-48 varlığı en sık direnç mekanizması, OXA-48 ve NDM-1 direnç geni birlikteliği ise ikinci sıklıkta bildirilmiştir (21)(22)(23)(24) .…”