Inhibitor of the NDM Enzyme
Aspergillomarasmine (AMA) was identified as an inhibitor of the New Delhi 
metallo-betalactamase (NDM) enzyme. This substance, when combined with meropenem, restored antibiotic activity against an NDM lab strain. AMA is a substance which was already tested in the past in humans. Concerns about interference with human metalloenzymes proved unfounded; it seems to have negligible toxicity. Currently, only colistin is active against NDM bacteria. None of the newer B-lactamase inhibitors (avibactam, MK-7655) inactivates NDMs.
Of note, tigecycline has poor activity against NDM-producers. [1]
Altered Antibiotic PK in Critically Ill Patients Requires Dosing Adjustments
Cefuroxime dosing, like that of other B-lactams, needs to be adjusted upwards in critically ill ICU patients. Especially when CLcr is in the normal range, standard doses are unlikely to achieve levels of T > MIC of 65% or greater. Hence, pathogens with MICs close to break point or patients with high CLcr may not be adequately covered with intermittent dosing. Based on PK/PD data, a continuous infusion of high doses may be able to still provide bacterial killing. As the authors point out, clinical studies to confirm this approach have yet to be performed.[2]
First Case of Ciprofloxacin-Resistant Legionella pneumophila
I guess it had to happen eventually: Bruin et al. report a patient infected with
L. pneumophila serogroup 1 who presented with severe respiratory insufficiency and interstial pneumonia. The organism MIC – tested at a reference lab – was 2 mg/L. Sequencing of the gyrA gene revealed a point mutation in the QRDR (quinolone resistance determining region). It was not clear whether the organism was resistant already prior to ciprofloxacin therapy.[3]
References
[1] A King Nature 2014, 510: 503
[2] M Carlier J Antimicrob Chemother 2014; 69: 2797
[3] J Bruin, J Antimicrob Chemother 69: 2869, 2014
