Monoclonal outbreak caused by ceftazidime-avibactam resistant blaOXA-48-positive, carbapenem-resistant Klebsiella pneumoniae in an intensive care unit

Purpose: (CRKP) isolates. Methods: -positive CRKP by VITEK 2 compact system and multiplex PCR, were included in the study. Colistin susceptibility of isolates was tested using the broth microdilution method. The Kirby-Bauer disk diffusion test was performed for CAZ-AVI susceptibility. Arbitrary primer sequence-based PCR (AP-PCR) was used to investigate genotypic similarity between the isolates. Results: carrier. AP-PCR revealed that 15 isolates showed five different genotypes. Eleven of the isolates were classified under genotype 1, leading to a clustering rate of 73.3%. Isolates in the genotype 1 group were defined as outbreak isolates. All but one of the genotype 1 outbreak isolates were resistant to all antibiotics studied, including CAZ-AVI and colistin. Conclusion: This study evaluated an intensive care unit outbreak caused by a clone resistant to CAZ-AVI, which has been reported to have susceptibility rates of up to 100% in OXA-48-producing CRKP isolates and is suggested as first choice therapy. To prevent the spread of CAZ-AVI-resistant CRKP isolates, it is essential to conduct active surveillance studies in hospitals. Especially ICUs - where these strains are common - should be routinely screened. Infection control practices in general must also be tightened.