RESUMO
Background: The treatment options for infections caused by MDR Gram-negative bacteria have been limited, especially for infections caused by bacteria that produce carbapenemases and/or ESBLs. Ceftolozane/tazobactam is a cephalosporin/ß-lactamase inhibitor developed to treat Gram-negative bacteria. Methods: Ceftolozane/tazobactam and 14 comparators (amikacin, aztreonam, cefepime, cefotaxime, cefoxitin, ceftazidime, ceftriaxone, ciprofloxacin, colistin, ertapenem, imipenem, levofloxacin, meropenem and piperacillin/tazobactam) were evaluated against Pseudomonas aeruginosa and Enterobacterales isolates collected from Kuwait and Oman (nâ=â606) during 2016-17. In addition, further analysis of resistance mechanisms to ceftolozane/tazobactam was done utilizing WGS. Non-susceptible isolates from ceftolozane/tazobactam surveillance were selected for analysis. Overall, 35 strains underwent WGS. Results: Among isolates from Kuwait, susceptibility of P. aeruginosa, Escherichia coli and Klebsiella pneumoniae to ceftolozane/tazobactam was 79.8%, 95.7% and 87.5%, respectively, and from Oman was 92.3%, 93.1% and 88.5%, respectively. No P. aeruginosa with a ceftolozane/tazobactam MIC <32â mg/L encoded ß-lactamases besides normal chromosomal enzymes (PDC variants or OXA-50-like) whereas all but one P. aeruginosa isolate with MIC >32â mg/L encoded either MBLs (60%), VEB-1 (19%) or additional OXAs (3.7%). Conclusions: Colistin followed by ceftolozane/tazobactam showed the greatest activity against P. aeruginosa. Enterobacterales showed more susceptibility to ceftolozane/tazobactam than to piperacillin/tazobactam, but meropenem and colistin showed better activity.
RESUMO
Two cases of fungemia caused by Magnusiomyces capitatus, an arthroconidial yeast-like fungus, in non-hematologic immunocompromised patients are described. Both patients died before definite diagnosis of M. capitatus was made. The report highlights that pending confirmation of the isolate by phenotypic and/or molecular methods, the characteristic morphologic features observed in Gram-stained smears of blood culture positive bottles can lead to early preliminary diagnosis, thus significantly reducing time required for initiating appropriate antifungal therapy.