Hasan Cenk Mirza1, Elvan Hortaç2, Aylin Altay Koçak2, M Hamiyet Demirkaya3, Buket Yayla4, Aylin Üsküdar Güçlü2, Ahmet Başustaoğlu2. 1. Department of Medical Microbiology, Başkent University Faculty of Medicine, Ankara, Turkey. Electronic address: h_cenkmirza@yahoo.com.tr. 2. Department of Medical Microbiology, Başkent University Faculty of Medicine, Ankara, Turkey. 3. Department of Infectious Diseases and Clinical Microbiology, Başkent University Faculty of Medicine, Ankara, Turkey. 4. Department of Medical Microbiology, Başkent University Faculty of Medicine, Adana Medical and Research Center, Adana, Turkey.
Abstract
OBJECTIVES: This study aimed to compare the activity of ceftazidime-avibactam (C/A), ceftolozane-tazobactam (C/T) and three anti-pseudomonal β-lactams (piperacillin-tazobactam, ceftazidime and cefepime) against a collection of meropenem-non-susceptible Pseudomonas aeruginosa (P. aeruginosa) clinical isolates recovered from two centres in Turkey. METHODS: A total of 102 unique patient isolates of meropenem-non-susceptible P. aeruginosa were included in the study. MICs of antimicrobials were determined by the gradient diffusion method. RESULTS: Overall susceptibility rates for C/A and C/T were 83.3% and 82.4%, respectively. Both C/A and C/T had better activity than any one of the three anti-pseudomonal β-lactams. According to the MIC50 values, C/T was the most potent agent against isolates. Although the susceptibility rates of isolates to C/T and C/A were similar, C/T (MIC50, 1 μg/mL) was four-fold more potent than C/A (MIC50, 4 μg/mL). The MIC50 values of C/A and C/T for the isolates that were non-susceptible to three β-lactams were significantly higher than those for isolates that were non-susceptible to zero, one or two β-lactams. Also, the C/A MIC50 value for the isolates that were non-susceptible to two β-lactams was higher than that for isolates which were non-susceptible to one β-lactam. CONCLUSIONS: C/A and C/T showed good activity against meropenem-non-susceptible P. aeruginosa isolates. However, resistance to these agents was not uncommon among these isolates. The overall β-lactam susceptibility profile of isolates seems to have an effect on the probability of susceptibility to C/A and C/T. Antimicrobial susceptibility testing should be performed for C/A and C/T if these agents are considered for treatment of infections caused by meropenem-non-susceptible P. aeruginosa.
OBJECTIVES: This study aimed to compare the activity of ceftazidime-avibactam (C/A), ceftolozane-tazobactam (C/T) and three anti-pseudomonal β-lactams (piperacillin-tazobactam, ceftazidime and cefepime) against a collection of meropenem-non-susceptible Pseudomonas aeruginosa (P. aeruginosa) clinical isolates recovered from two centres in Turkey. METHODS: A total of 102 unique patient isolates of meropenem-non-susceptible P. aeruginosa were included in the study. MICs of antimicrobials were determined by the gradient diffusion method. RESULTS: Overall susceptibility rates for C/A and C/T were 83.3% and 82.4%, respectively. Both C/A and C/T had better activity than any one of the three anti-pseudomonal β-lactams. According to the MIC50 values, C/T was the most potent agent against isolates. Although the susceptibility rates of isolates to C/T and C/A were similar, C/T (MIC50, 1 μg/mL) was four-fold more potent than C/A (MIC50, 4 μg/mL). The MIC50 values of C/A and C/T for the isolates that were non-susceptible to three β-lactams were significantly higher than those for isolates that were non-susceptible to zero, one or two β-lactams. Also, the C/A MIC50 value for the isolates that were non-susceptible to two β-lactams was higher than that for isolates which were non-susceptible to one β-lactam. CONCLUSIONS: C/A and C/T showed good activity against meropenem-non-susceptible P. aeruginosa isolates. However, resistance to these agents was not uncommon among these isolates. The overall β-lactam susceptibility profile of isolates seems to have an effect on the probability of susceptibility to C/A and C/T. Antimicrobial susceptibility testing should be performed for C/A and C/T if these agents are considered for treatment of infections caused by meropenem-non-susceptible P. aeruginosa.
Authors: Paulina Paprocka; Bonita Durnaś; Angelika Mańkowska; Karol Skłodowski; Grzegorz Król; Magdalena Zakrzewska; Michał Czarnowski; Patrycja Kot; Kamila Fortunka; Stanisław Góźdź; Paul B Savage; Robert Bucki Journal: Infect Drug Resist Date: 2021-12-25 Impact factor: 4.003