Spiropiperidyl rifabutins: expanded in vitro testing against ESKAPE pathogens and select bacterial biofilms.

The expanded microbiological evaluation of a series of rifastures, novel spiropiperidyl rifamycin derivatives, against clinically relevant ESKAPE bacteria has identified several analogs with promising in vitro bioactivities against antibiotic-resistant strains of Enterococcus faecium and Staphylococcus aureus. Thirteen of the rifastures displayed minimum inhibitory concentrations (MICs) below 1 µg/ml against the methicillin- and vancomycin-resistant forms of S. aureus and E.

The effect of paratuberculosis on milk yield--A systematic review and meta-analysis.

Bovine paratuberculosis is a disease characterized by chronic granulomatous enteritis causing protein-losing enteropathy. Adverse effects on animal productivity are key drivers in the attempt to control paratuberculosis at the farm level. Economic models require an accurate estimation of the production effects associated with paratuberculosis.

Strong in vitro activities of two new rifabutin analogs against multidrug-resistant Mycobacterium tuberculosis.

Two new rifabutin analogs, RFA-1 and RFA-2, show high in vitro antimycobacterial activities against Mycobacterium tuberculosis. MIC values of RFA-1 and RFA-2 were ≤0.02 μg/ml against rifamycin-susceptible strains and 0.

New rifabutin analogs: synthesis and biological activity against Mycobacterium tuberculosis.

The synthesis, structure, and biological evaluation of a series of novel rifamycin derivatives, Rifastures (RFA) with potent anti-tuberculosis activity are presented. Some of these derivatives showed higher in vitro activity than rifabutin and rifampicin against not only Mycobacterium tuberculosis strains but also against MAC and Mycobacterium kansasii.

NMR spectroscopic analysis of new spiro-piperidylrifamycins.

New spiro-piperidylrifamycin derivatives are presented. These compounds were synthesized from the reaction of 3-amino-4-iminorifamycin S and enantiomerically pure 4-piperidones, which generate diasteroisomeric rifabutin analogues with a new stereocentre at the spiranic carbon. The (1)H and (13)C NMR spectra of these new compounds, and also the configuration of the new stereogenic centres, were assigned using 2D NMR spectroscopic techniques.